Sample records for micro-angiographic fluoroscope hs-maf

  1. Region-of-interest micro-angiographic fluoroscope detector used in aneurysm and artery stenosis diagnoses and treatment

    Wang, Weiyuan; Ionita, Ciprian; Huang, Ying; Qu, Bin; Panse, Ashish; Jain, Amit; Bednarek, Daniel R.; Rudin, Stephen


    Due to the need for high-resolution angiographic and interventional vascular imaging, a Micro-Angiographic Fluoroscope (MAF) detector with a Control, Acquisition, Processing, and Image Display System (CAPIDS) was installed on a detector changer, which was attached to the C-arm of a clinical angiographic unit at a local hospital. The MAF detector provides high-resolution, high-sensitivity, and real-time imaging capabilities and consists of a 300 μm thick CsI phosphor, a dual stage micro-channel plate light image intensifier (LII) coupled to a fiber optic taper (FOT), and a scientific grade frame-transfer CCD camera, providing an image matrix of 1024×1024 35 μm effective square pixels with 12 bit depth. The changer allows the MAF region-of-interest (ROI) detector to be inserted in front of the Image Intensifier (II) when higher resolution is needed during angiographic or interventional vascular imaging procedures, e.g. endovascular stent deployment. The CAPIDS was developed and implemented using Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW) software and provides a user-friendly interface that enables control of several clinical radiographic imaging modes of the MAF including: fluoroscopy, roadmapping, radiography, and digital-subtraction-angiography (DSA). The total system has been used for image guidance during endovascular image-guided interventions (EIGI) for diagnosing and treating artery stenoses and aneurysms using self-expanding endovascular stents and coils in fifteen patient cases, which have demonstrated benefits of using the ROI detector. The visualization of the fine detail of the endovascular devices and the vessels generally gave the clinicians confidence on performing neurovascular interventions and in some instances contributed to improved interventions.

  2. Design considerations for a new, high resolution Micro-Angiographic Fluoroscope based on a CMOS sensor (MAF-CMOS).

    Loughran, Brendan; Swetadri Vasan, S N; Singh, Vivek; Ionita, Ciprian N; Jain, Amit; Bednarek, Daniel R; Titus, Albert; Rudin, Stephen


    The detectors that are used for endovascular image-guided interventions (EIGI), particularly for neurovascular interventions, do not provide clinicians with adequate visualization to ensure the best possible treatment outcomes. Developing an improved x-ray imaging detector requires the determination of estimated clinical x-ray entrance exposures to the detector. The range of exposures to the detector in clinical studies was found for the three modes of operation: fluoroscopic mode, high frame-rate digital angiographic mode (HD fluoroscopic mode), and DSA mode. Using these estimated detector exposure ranges and available CMOS detector technical specifications, design requirements were developed to pursue a quantum limited, high resolution, dynamic x-ray detector based on a CMOS sensor with 50 μm pixel size. For the proposed MAF-CMOS, the estimated charge collected within the full exposure range was found to be within the estimated full well capacity of the pixels. Expected instrumentation noise for the proposed detector was estimated to be 50-1,300 electrons. Adding a gain stage such as a light image intensifier would minimize the effect of the estimated instrumentation noise on total image noise but may not be necessary to ensure quantum limited detector operation at low exposure levels. A recursive temporal filter may decrease the effective total noise by 2 to 3 times, allowing for the improved signal to noise ratios at the lowest estimated exposures despite consequent loss in temporal resolution. This work can serve as a guide for further development of dynamic x-ray imaging prototypes or improvements for existing dynamic x-ray imaging systems.

  3. Design considerations for a new high resolution Micro-Angiographic Fluoroscope based on a CMOS sensor (MAF-CMOS)

    Loughran, Brendan; Swetadri Vasan, S. N.; Singh, Vivek; Ionita, Ciprian N.; Jain, Amit; Bednarek, Daniel R.; Titus, Albert H.; Rudin, Stephen


    The detectors that are used for endovascular image-guided interventions (EIGI), particularly for neurovascular interventions, do not provide clinicians with adequate visualization to ensure the best possible treatment outcomes. Developing an improved x-ray imaging detector requires the determination of estimated clinical x-ray entrance exposures to the detector. The range of exposures to the detector in clinical studies was found for the three modes of operation: fluoroscopic mode, high frame-rate digital angiographic mode (HD fluoroscopic mode), and DSA mode. Using these estimated detector exposure ranges and available CMOS detector technical specifications, design requirements were developed to pursue a quantum limited, high resolution, dynamic x-ray detector based on a CMOS sensor with 50 μm pixel size. For the proposed MAF-CMOS, the estimated charge collected within the full exposure range was found to be within the estimated full well capacity of the pixels. Expected instrumentation noise for the proposed detector was estimated to be 50-1,300 electrons. Adding a gain stage such as a light image intensifier would minimize the effect of the estimated instrumentation noise on total image noise but may not be necessary to ensure quantum limited detector operation at low exposure levels. A recursive temporal filter may decrease the effective total noise by 2 to 3 times, allowing for the improved signal to noise ratios at the lowest estimated exposures despite consequent loss in temporal resolution. This work can serve as a guide for further development of dynamic x-ray imaging prototypes or improvements for existing dynamic x-ray imaging systems.

  4. SU-E-I-26: Estimation of Micro-Angiographic Fluoroscope (MAF) Gain Settings for Digital Subtraction Angiography (DSA) Based on the Fluoroscopic Exposure.

    Ionita, C; Loughran, B; Nagesh, S Setlur; Jain, A; Bednarek, D; Rudin, S


    The MAF is a new high-resolution detector which is being clinically evaluated in neuro-vascular procedures. The detector contains a large-dynamic-range, high-sensitivity light image intensifier with variable gain. Since the MAF is a research prototype only partially integrated with the clinical system, x-ray technique parameters must be set manually. To improve workflow we developed an automatic method to estimate and set the proper LII voltage (MAF gain) for DSA acquisition based on the fluoroscopic parameters. The detector entrance exposure (XD) can be written as the x-ray tube output exposure (Xo) times an object attenuation factor and an inverse-square correction. If the object attenuation, scatter and distances are unchanged and the effect of x-ray kVp changes are neglected, then the DSA XD can be expressed as the ratio of Xo(DSA)/Xo(Fluoroscopy) multiplied with XD(fluoroscopy). We measured Xo for fluoroscopy and DSA for mAs and kVp ranges appropriate to neuro- vascular interventions and fit the data with a 2D function. To estimate the XD(Fluoroscopy) we derived a curve of XD versus LII-voltage for a mid- dynamic-range average pixel gray-level. Since the MAF system during clinical fluoroscopy automatically adjusts the LII voltage until the desired gray-level value is achieved, by reading that voltage we can estimate the XD(Fluoroscopy). Using the 2D-fit function, Xo(DSA) is automatically calculated for the kVp and mA values set and XD(DSA) can be estimated using the relation above. Using the inverse LII calibration curve, the proper LII-voltage can be determined for the desired average gray-level. The algorithm was implemented and evaluated in thirty-two in-vivo DSA runs on rabbits. The proper LII voltage was selected in all cases with no failures. Using the fluoroscopic LII gain setting to determine the appropriate DSA setting can greatly improve the workflow in clinical evaluations of the MAF. NIH Grants R01-EB008425, R01-EB002873 and an equipment grant from

  5. Graphics Processing Unit (GPU) implementation of image processing algorithms to improve system performance of the Control, Acquisition, Processing, and Image Display System (CAPIDS) of the Micro-Angiographic Fluoroscope (MAF).

    Vasan, S N Swetadri; Ionita, Ciprian N; Titus, A H; Cartwright, A N; Bednarek, D R; Rudin, S


    We present the image processing upgrades implemented on a Graphics Processing Unit (GPU) in the Control, Acquisition, Processing, and Image Display System (CAPIDS) for the custom Micro-Angiographic Fluoroscope (MAF) detector. Most of the image processing currently implemented in the CAPIDS system is pixel independent; that is, the operation on each pixel is the same and the operation on one does not depend upon the result from the operation on the other, allowing the entire image to be processed in parallel. GPU hardware was developed for this kind of massive parallel processing implementation. Thus for an algorithm which has a high amount of parallelism, a GPU implementation is much faster than a CPU implementation. The image processing algorithm upgrades implemented on the CAPIDS system include flat field correction, temporal filtering, image subtraction, roadmap mask generation and display window and leveling. A comparison between the previous and the upgraded version of CAPIDS has been presented, to demonstrate how the improvement is achieved. By performing the image processing on a GPU, significant improvements (with respect to timing or frame rate) have been achieved, including stable operation of the system at 30 fps during a fluoroscopy run, a DSA run, a roadmap procedure and automatic image windowing and leveling during each frame.

  6. Graphics processing unit (GPU) implementation of image processing algorithms to improve system performance of the control acquisition, processing, and image display system (CAPIDS) of the micro-angiographic fluoroscope (MAF)

    Swetadri Vasan, S. N.; Ionita, Ciprian N.; Titus, A. H.; Cartwright, A. N.; Bednarek, D. R.; Rudin, S.


    We present the image processing upgrades implemented on a Graphics Processing Unit (GPU) in the Control, Acquisition, Processing, and Image Display System (CAPIDS) for the custom Micro-Angiographic Fluoroscope (MAF) detector. Most of the image processing currently implemented in the CAPIDS system is pixel independent; that is, the operation on each pixel is the same and the operation on one does not depend upon the result from the operation on the other, allowing the entire image to be processed in parallel. GPU hardware was developed for this kind of massive parallel processing implementation. Thus for an algorithm which has a high amount of parallelism, a GPU implementation is much faster than a CPU implementation. The image processing algorithm upgrades implemented on the CAPIDS system include flat field correction, temporal filtering, image subtraction, roadmap mask generation and display window and leveling. A comparison between the previous and the upgraded version of CAPIDS has been presented, to demonstrate how the improvement is achieved. By performing the image processing on a GPU, significant improvements (with respect to timing or frame rate) have been achieved, including stable operation of the system at 30 fps during a fluoroscopy run, a DSA run, a roadmap procedure and automatic image windowing and leveling during each frame.

  7. Evaluation and Comparison of High-Resolution (HR) and High-Light (HL) Phosphors in the Micro-Angiographic Fluoroscope (MAF) using Generalized Linear Systems Analyses (GMTF, GDQE) that include the Effect of Scatter, Magnification and Detector Characteristics.

    Gupta, Sandesh K; Jain, Amit; Bednarek, Daniel R; Rudin, Stephen


    In this study, we evaluated the imaging characteristics of the high-resolution, high-sensitivity micro-angiographic fluoroscope (MAF) with 35-micron pixel-pitch when used with different commercially-available 300 micron thick phosphors: the high resolution (HR) and high light (HL) from Hamamatsu. The purpose of this evaluation was to see if the HL phosphor with its higher screen efficiency could be replaced with the HR phosphor to achieve improved resolution without an increase in noise resulting from the HR's decreased light-photon yield. We designated the detectors MAF-HR and MAF-HL and compared them with a standard flat panel detector (FPD) (194 micron pixel pitch and 600 micron thick CsI(Tl)). For this comparison, we used the generalized linear-system metrics of GMTF, GNNPS and GDQE which are more realistic measures of total system performance since they include the effect of scattered radiation, focal spot distribution, and geometric un-sharpness. Magnifications (1.05-1.15) and scatter fractions (0.28 and 0.33) characteristic of a standard head phantom were used. The MAF-HR performed significantly better than the MAF-HL at high spatial frequencies. The ratio of GMTF and GDQE of the MAF-HR compared to the MAF-HL at 3(6) cycles/mm was 1.45(2.42) and 1.23(2.89), respectively. Despite significant degradation by inclusion of scatter and object magnification, both MAF-HR and MAF-HL provide superior performance over the FPD at higher spatial frequencies with similar performance up to the FPD's Nyquist frequency of 2.5 cycles/mm. Both substantially higher resolution and improved GDQE can be achieved with the MAF using the HR phosphor instead of the HL phosphor.

  8. SU-E-I-53: Comparison of Kerma-Area-Product Between the Micro-Angiographic Fluoroscope (MAF) and a Flat Panel Detector (FPD) as Used in Neuro-Endovascular Procedures

    Vijayan, S; Rana, V; Nagesh, S Setlur; Xiong, Z; Rudin, S; Bednarek, D [Toshiba Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY (United States)


    Purpose: To determine the reduction of integral dose to the patient when using the micro-angiographic fluoroscope (MAF) compared to when using the standard flat-panel detector (FPD) for the techniques used during neurointerventional procedures. Methods: The MAF is a small field-of-view, high resolution x-ray detector which captures 1024 x 1024 pixels with an effective pixel size of 35μm and is capable of real-time imaging up to 30 frames per second. The MAF was used in neuro-interventions during those parts of the procedure when high resolution was needed and the FPD was used otherwise. The technique parameters were recorded when each detector was used and the kerma-area-product (KAP) per image frame was determined. KAP values were calculated for seven neuro interventions using premeasured calibration files of output as a function of kVp and beam filtration and included the attenuation of the patient table for the frontal projections to be more representative of integral patient dose. The air kerma at the patient entrance was multiplied by the beam area at that point to obtain the KAP values. The ranges of KAP values per frame were determined for the range of technique parameters used during the clinical procedures. To appreciate the benefit of the higher MAF resolution in the region of interventional activity, DA technique parameters were generally used with the MAF. Results: The lowest and highest values of KAP per frame for the MAF in DA mode were 4 and 50 times lower, respectively, compared to those of the FPD in pulsed fluoroscopy mode. Conclusion: The MAF was used in those parts of the clinical procedures when high resolution and image quality was essential. The integral patient dose as represented by the KAP value was substantially lower when using the MAF than when using the FPD due to the much smaller volume of tissue irradiated. This research was supported in part by Toshiba Medical Systems Corporation and NIH Grant R01EB002873.

  9. Improved contrast and spatial resolution with Single Photon Counting (SPC) for an area x-ray imager, the newly developed high-resolution Micro-Angiographic Fluoroscopic (MAF) detector.

    Jain, Amit; Kuhls-Gilcrist, Andrew; Bednarek, Daniel R; Rudin, Stephen


    Although in radiological imaging, the prevailing mode of acquisition is the integration of the energy deposited by all x-rays absorbed in the imaging detector, much improvement in image spatial and contrast resolution could be achieved if each individual x-ray photon were detected and counted separately. In this work we compare the conventional energy integration (EI) mode with the new single photon counting (SPC) mode for a recently developed high-resolution Micro-Angiographic Fluoroscopic (MAF) detector, which is uniquely capable of both modes of operation. The MAF has 1024×1024 pixels of 35 microns effective size and is capable of real-time imaging at 30 fps. The large variable gain of its light image intensifier (LII) provides quantum limited operation with essentially no additive instrumentation noise and enables the MAF to operate in both EI and the very sensitive low-exposure SPC modes. We used high LII gain with very low exposure (SPC mode and higher exposure per frame with lower gain for EI mode. Multiple signal-thresholded frames were summed in SPC mode to provide an integrated frame with the same total exposure as EI mode. A heavily K-edge filtered x-ray beam (average energy of 31 keV) was used to provide a nearly monochromatic spectrum. The MTF measured using a standard slit method showed a dramatic improvement for the SPC mode over the EI mode at all frequencies. Images of a line pair phantom also showed improved spatial resolution with 12 lp/mm visible in SPC mode compared to only 8 lp/mm in EI mode. In SPC mode, images of human distal and middle phalanges showed the trabecular structures of the bone with far better contrast and detail. These improvements with the SPC mode should be advantageous for clinical applications where high resolution and/or high contrast are essential such as in mammography and extremity imaging as well as for dual modality applications, which combine nuclear medicine and x-ray imaging using a single detector.

  10. Progress in the development of a new angiography suite including the high resolution micro-angiographic fluoroscope (MAF): a control, acquisition, processing, and image display system (CAPIDS), and a new detector changer integrated into a commercial C-arm angiography unit to enable clinical use

    Wang, Weiyuan; Ionita, Ciprian N.; Keleshis, Christos; Kuhls-Gilcrist, Andrew; Jain, Amit; Bednarek, Daniel; Rudin, Stephen


    Due to the high-resolution needs of angiographic and interventional vascular imaging, a Micro-Angiographic Fluoroscope (MAF) detector with a Control, Acquisition, Processing, and Image Display System (CAPIDS) was installed on a detector changer which was attached to the C-arm of a clinical angiographic unit. The MAF detector provides high-resolution, high-sensitivity, and real-time imaging capabilities and consists of a 300 μm-thick CsI phosphor, a dual stage micro-channel plate light image intensifier (LII) coupled to a fiber optic taper (FOT), and a scientific grade frame-transfer CCD camera, providing an image matrix of 1024×1024 35 μm square pixels with 12 bit depth. The Solid-State X-Ray Image Intensifier (SSXII) is an EMCCD (Electron Multiplying charge-coupled device) based detector which provides an image matrix of 1k×1k 32 μm square pixels with 12 bit depth. The changer allows the MAF or a SSXII region-of-interest (ROI) detector to be inserted in front of the standard flat-panel detector (FPD) when higher resolution is needed during angiographic or interventional vascular imaging procedures. The CAPIDS was developed and implemented using LabVIEW software and provides a user-friendly interface that enables control of several clinical radiographic imaging modes of the MAF or SSXII including: fluoroscopy, roadmapping, radiography, and digital-subtraction-angiography (DSA). The total system has been used for image guidance during endovascular image-guided interventions (EIGI) using prototype self-expanding asymmetric vascular stents (SAVS) in over 10 rabbit aneurysm creation and treatment experiments which have demonstrated the system's potential benefits for future clinical use.

  11. WE-G-204-05: Relative Object Detectability Evaluation of a New High Resolution A-Se Direct Detection System Compared to Indirect Micro-Angiographic Fluoroscopic (MAF) Detectors

    Russ, M; Nagesh, S Setlur; Ionita, C; Bednarek, D; Rudin, S [Toshiba Stroke and Vascular Research Center, University at Buffalo (SUNY), Buffalo, NY (United States); Scott, C; Karim, K [University of Waterloo, Waterloo, ON (Canada)


    Purpose: To evaluate the task specific imaging performance of a new 25µm pixel pitch, 1000µm thick amorphous selenium direct detection system with CMOS readout for typical angiographic exposure parameters using the relative object detectability (ROD) metric. Methods: The ROD metric uses a simulated object function weighted at each spatial frequency by the detectors’ detective quantum efficiency (DQE), which is an intrinsic performance metric. For this study, the simulated objects were aluminum spheres of varying diameter (0.05–0.6mm). The weighted object function is then integrated over the full range of detectable frequencies inherent to each detector, and a ratio is taken of the resulting value for two detectors. The DQE for the 25µm detector was obtained from a simulation of a proposed a-Se detector using an exposure of 200µR for a 50keV x-ray beam. This a-Se detector was compared to two microangiographic fluoroscope (MAF) detectors [the MAF-CCD with pixel size of 35µm and Nyquist frequency of 14.2 cycles/mm and the MAF-CMOS with pixel size of 75µm and Nyquist frequency of 6.6 cycles/mm] and a standard flat-panel detector (FPD with pixel size of 194µm and Nyquist frequency of 2.5cycles/mm). Results: ROD calculations indicated vastly superior performance by the a-Se detector in imaging small aluminum spheres. For the 50µm diameter sphere, the ROD values for the a-Se detector compared to the MAF-CCD, the MAF-CMOS, and the FPD were 7.3, 9.3 and 58, respectively. Detector performance in the low frequency regime was dictated by each detector’s DQE(0) value. Conclusion: The a-Se with CMOS readout is unique and appears to have distinctive advantages of incomparable high resolution, low noise, no readout lag, and expandable design. The a-Se direct detection system will be a powerful imaging tool in angiography, with potential break-through applications in diagnosis and treatment of neuro-vascular disease. Supported by NIH Grant: 2R01EB002873 and an

  12. SU-D-204-05: Quantitative Comparison of a High Resolution Micro-Angiographic Fluoroscopic (MAF) Detector with a Standard Flat Panel Detector (FPD) Using the New Metric of Generalized Measured Relative Object Detectability (GM-ROD)

    Russ, M; Ionita, C; Bednarek, D; Rudin, S [Toshiba Stroke and Vascular Research Center, University at Buffalo (SUNY), Buffalo, NY (United States)


    Purpose: In endovascular image-guided neuro-interventions, visualization of fine detail is paramount. For example, the ability of the interventionist to visualize the stent struts depends heavily on the x-ray imaging detector performance. Methods: A study to examine the relative performance of the high resolution MAF-CMOS (pixel size 75µm, Nyquist frequency 6.6 cycles/mm) and a standard Flat Panel Detector (pixel size 194µm, Nyquist frequency 2.5 cycles/mm) detectors in imaging a neuro stent was done using the Generalized Measured Relative Object Detectability (GM-ROD) metric. Low quantum noise images of a deployed stent were obtained by averaging 95 frames obtained by both detectors without changing other exposure or geometric parameters. The square of the Fourier transform of each image is taken and divided by the generalized normalized noise power spectrum to give an effective measured task-specific signal-to-noise ratio. This expression is then integrated from 0 to each of the detector’s Nyquist frequencies, and the GM-ROD value is determined by taking a ratio of the integrals for the MAF-CMOS to that of the FPD. The lower bound of integration can be varied to emphasize high frequencies in the detector comparisons. Results: The MAF-CMOS detector exhibits vastly superior performance over the FPD when integrating over all frequencies, yielding a GM-ROD value of 63.1. The lower bound of integration was stepped up in increments of 0.5 cycles/mm for higher frequency comparisons. As the lower bound increased, the GM-ROD value was augmented, reflecting the superior performance of the MAF-CMOS in the high frequency regime. Conclusion: GM-ROD is a versatile metric that can provide quantitative detector and task dependent comparisons that can be used as a basis for detector selection. Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation.

  13. Evaluation of intracranial aneurysm coil embolization in phantoms and patients using a high resolution microangiographic fluoroscope (MAF)

    Ionita, Ciprian N.; Jain, Amit; Loughran, Brendan; Swetadri Vasan, S. N.; Bednarek, Daniel R.; Levy, Elad; Siddiqui, Adnan H.; Snyder, Kenneth V.; Hopkins, L. N.; Rudin, Stephen


    Intracranial aneurysm (IA) embolization using Gugliemi Detachable Coils (GDC) under x-ray fluoroscopic guidance is one of the most important neuro-vascular interventions. Coil deposition accuracy is key and could benefit substantially from higher resolution imagers such as the micro-angiographic fluoroscope (MAF). The effect of MAF guidance improvement over the use of standard Flat Panels (FP) is challenging to assess for such a complex procedure. We propose and investigate a new metric, inter-frame cross-correlation sensitivity (CCS), to compare detector performance for such procedures. Pixel (P) and histogram (H) CCS's were calculated as one minus the cross-correlation coefficients between pixel values and histograms for the region of interest at successive procedure steps. IA treatment using GDC's was simulated using an anthropomorphic head phantom which includes an aneurysm. GDC's were deposited in steps of 3 cm and the procedure was imaged with a FP and the MAF. To measure sensitivity to detect progress of the procedure by change in images of successive steps, an ROI was selected over the aneurysm location and pixel-value and histogram changes were calculated after each step. For the FP, after 4 steps, the H and P CCSs between successive steps were practically zero, indicating that there were no significant changes in the observed images. For the MAF, H and P CCSs were greater than zero even after 10 steps (30 cm GDC), indicating observable changes. Further, the proposed quantification method was applied for evaluation of seven patients imaged using the MAF, yielding similar results (H and P CCSs greater than zero after the last GDC deposition). The proposed metric indicates that the MAF can offer better guidance during such procedures.

  14. New Jersey's Thomas Edison and the fluoroscope.

    Tselos, G D


    Thomas Edison played a major role in the development of early x-ray technology in 1896, notably increasing tube power and reliability and making the fluoroscope a practical instrument. Eventually, Edison would move x-ray technology from the laboratory to the marketplace.

  15. Fluoroscopic image-guided intervention system for transbronchial localization

    Rai, Lav; Keast, Thomas M.; Wibowo, Henky; Yu, Kun-Chang; Draper, Jeffrey W.; Gibbs, Jason D.


    Reliable transbronchial access of peripheral lung lesions is desirable for the diagnosis and potential treatment of lung cancer. This procedure can be difficult, however, because accessory devices (e.g., needle or forceps) cannot be reliably localized while deployed. We present a fluoroscopic image-guided intervention (IGI) system for tracking such bronchoscopic accessories. Fluoroscopy, an imaging technology currently utilized by many bronchoscopists, has a fundamental shortcoming - many lung lesions are invisible in its images. Our IGI system aligns a digitally reconstructed radiograph (DRR) defined from a pre-operative computed tomography (CT) scan with live fluoroscopic images. Radiopaque accessory devices are readily apparent in fluoroscopic video, while lesions lacking a fluoroscopic signature but identifiable in the CT scan are superimposed in the scene. The IGI system processing steps consist of: (1) calibrating the fluoroscopic imaging system; (2) registering the CT anatomy with its depiction in the fluoroscopic scene; (3) optical tracking to continually update the DRR and target positions as the fluoroscope is moved about the patient. The end result is a continuous correlation of the DRR and projected targets with the anatomy depicted in the live fluoroscopic video feed. Because both targets and bronchoscopic devices are readily apparent in arbitrary fluoroscopic orientations, multiplane guidance is straightforward. The system tracks in real-time with no computational lag. We have measured a mean projected tracking accuracy of 1.0 mm in a phantom and present results from an in vivo animal study.

  16. Quantitative comparison using generalized relative object detectability (G-ROD) metrics of an amorphous selenium detector with high resolution microangiographic fluoroscopes (MAF) and standard flat panel detectors (FPD)

    Russ, M.; Shankar, A.; Jain, A.; Setlur Nagesh, S. V.; Ionita, C. N.; Scott, C.; Karim, K. S.; Bednarek, D. R.; Rudin, S.


    A novel amorphous selenium (a-Se) direct detector with CMOS readout has been designed, and relative detector performance investigated. The detector features include a 25μm pixel pitch, and 1000μm thick a-Se layer operating at 10V/μm bias field. A simulated detector DQE was determined, and used in comparative calculations of the Relative Object Detectability (ROD) family of prewhitening matched-filter (PWMF) observer and non-pre-whitening matched filter (NPWMF) observer model metrics to gauge a-Se detector performance against existing high resolution micro-angiographic fluoroscopic (MAF) detectors and a standard flat panel detector (FPD). The PWMF-ROD or ROD metric compares two x-ray imaging detectors in their relative abilities in imaging a given object by taking the integral over spatial frequencies of the Fourier transform of the detector DQE weighted by an object function, divided by the comparable integral for a different detector. The generalized-ROD (G-ROD) metric incorporates clinically relevant parameters (focal- spot size, magnification, and scatter) to show the degradation in imaging performance for detectors that are part of an imaging chain. Preliminary ROD calculations using simulated spheres as the object predicted superior imaging performance by the a-Se detector as compared to existing detectors. New PWMF-G-ROD and NPWMF-G-ROD results still indicate better performance by the a-Se detector in an imaging chain over all sphere sizes for various focal spot sizes and magnifications, although a-Se performance advantages were degraded by focal spot blurring. Nevertheless, the a-Se technology has great potential to provide break- through abilities such as visualization of fine details including of neuro-vascular perforator vessels and of small vascular devices.

  17. Development of fluoroscopic registration in spinal neuronavigation

    Abbasi, Hamid R.; Grzeszczuk, Robert; Chin, Shao; Holz, H.; Hariri, Sanaz; Badr, Rana; Kim, Daniel; Adler, John R.; Shahidi, Ramin


    We present a system involving a computer-instrumented fluoroscope for the purpose of 3D navigation and guidance using pre-operative diagnostic scans as a reference. The goal of the project is to devise a computer-assisted tool that will improve the accuracy, reduce risk, minimize the invasiveness, and shorten the time it takes to perform a variety of neurosurgical and orthopedic procedures of the spine. For this purpose we propose an apparatus that will track surgical tools and localize them with respect to the patient's 3D anatomy and pre-operative 3D diagnostic scans using intraoperative fluoroscopy for in situ registration and localization of embedded fiducials. Preliminary studies have found a fiducial registration error (FRE) of 1.41 mm and a Target Localization Error (TLE) of 0.48 mm. The resulting system leverages equipment already commonly available in the operating room (OR), providing an important new functionality that is free of many current limitations, such as the inadequacy of skin fiducials for spinal neuronavigation, while keeping costs contained.

  18. Fluoroscopic studies of the upper gastrointestinal tract: techniques and indications.

    Sánchez-Carpintero de la Vega, M; García Villar, C

    Fluoroscopic studies of the gastrointestinal tract are becoming increasing less common due to the introduction of other imaging techniques such as computed tomography and magnetic resonance imaging and to the increased availability of endoscopy. Nevertheless, fluoroscopic studies of the gastrointestinal tract continue to appear in clinical guidelines and some of their indications are still valid. These studies are dynamic, operator-dependent examinations that require training to obtain the maximum diagnostic performance. This review aims to describe the technique and bring the indications for this imaging modality up to date. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Dosimetry with a fluoroscopic electronic portal imaging device

    K.L. Pasma (Kasper)


    textabstractechniques for dosimetric verification of radiotherapy treatments using a CCD camera based fluoroscopic electronic portal imaging device (EPID) are described. The dosimetric characteristics of the EPID were investigated and a method was developed to derive portal dose images (PDIs) from m

  20. Multimodality calibration for simultaneous fluoroscopic and nuclear imaging

    Beijst, Casper; Elschot, Mattijs; van der Velden, Sanda; de Jong, Hugo W A M


    BACKGROUND: Simultaneous real-time fluoroscopic and nuclear imaging could benefit image-guided (oncological) procedures. To this end, a hybrid modality is currently being developed by our group, by combining a c-arm with a gamma camera and a four-pinhole collimator. Accurate determination of the sys

  1. Ulcerated Radiodermatitis Induced after Fluoroscopically Guided Stent Implantation Angioplasty

    Herz-Ruelas, Maira Elizabeth; Gómez-Flores, Minerva; Moxica-del Angel, Joaquín; Miranda-Maldonado, Ivett; Gutiérrez-Villarreal, Ilse Marilú; Villarreal-Rodríguez, Adriana Orelia


    Cases of radiation-induced skin injury after fluoroscopically guided procedures have been reported since 1996, though the majority of them have been published in Radiology and Cardiology literature, less frequently in Dermatology journals. Chronic radiation dermatitis induced by fluoroscopy can be difficult to diagnose; a high grade of suspicion is required. We report a case of an obese 46-year-old man with hypertension, dyslipidemia, and severe coronary artery disease. He developed a pruritic and painful atrophic ulcerated skin plaque over his left scapula, six months after fluoroscopically guided stent implantation angioplasty. The diagnosis of radiodermatitis was confirmed histologically. We report this case to emphasize the importance of recognizing fluoroscopy as a cause of radiation dermatitis. A good clinical follow-up at regular intervals is important after long and complicated procedures, since the most prevalent factor for injury is long exposure time. PMID:25276441

  2. Ulcerated Radiodermatitis Induced after Fluoroscopically Guided Stent Implantation Angioplasty

    Maira Elizabeth Herz-Ruelas


    Full Text Available Cases of radiation-induced skin injury after fluoroscopically guided procedures have been reported since 1996, though the majority of them have been published in Radiology and Cardiology literature, less frequently in Dermatology journals. Chronic radiation dermatitis induced by fluoroscopy can be difficult to diagnose; a high grade of suspicion is required. We report a case of an obese 46-year-old man with hypertension, dyslipidemia, and severe coronary artery disease. He developed a pruritic and painful atrophic ulcerated skin plaque over his left scapula, six months after fluoroscopically guided stent implantation angioplasty. The diagnosis of radiodermatitis was confirmed histologically. We report this case to emphasize the importance of recognizing fluoroscopy as a cause of radiation dermatitis. A good clinical follow-up at regular intervals is important after long and complicated procedures, since the most prevalent factor for injury is long exposure time.

  3. Cyclic voiding cystouretrography without the use of fluoroscopic monitoring

    Kadioglu, Alev [ALKA Medical Imaging Center, Buyukdere Cad. Levent Apt. No: 36/16, 80200-Mecidiyekoy, Istanbul (Turkey)]. E-mail:; Mihmanli, Ismail [Istanbul University, Cerrahpasa Medical Faculty, Department of Radiology, 34300-Istanbul (Turkey); Kantarci, Fatih [Istanbul University, Cerrahpasa Medical Faculty, Department of Radiology, 34300-Istanbul (Turkey); Tekes, Aylin [ALKA Medical Imaging Center, Buyukdere Cad. Levent Apt. No: 36/16, 80200-Mecidiyekoy, Istanbul (Turkey); Uysal, Omer [Istanbul University, Cerrahpasa Medical Faculty, Department of Biostatistics, 34300-Istanbul (Turkey)


    Purpose: To determine whether cyclic voiding cystourethrography (VCUG) examinations can be performed without using real-time fluoroscopic monitoring. Materials and methods: VCUG examinations were performed in 209 children (133 girls and 76 boys). In each child, it was performed in a cyclic manner (three consecutive cycles) without using fluoroscopic monitoring and one radiograph was taken in each cycle of the examination. All patients were sedated by midazolam prior to examination. The degree of vesicoureteric reflux (VUR) was graded for each of the kidney ureter units (KUU) (total 418 KUU) separately. Statistical analysis included the comparison of the presence and absence of VUR and three ordinal-matched comparisons of each cycle. Results: VCUG was detected in 37.3% of the children (78/209) and 28.7% (120/418) of the KUU. The absence of or same degree of VUR in three consecutive cycles were obtained in 345 KUU and the agreement was calculated as 82.5%. The same degree and presence of reflux were found in 85 and 89 refluxing KUU, the same negative findings (absence of VUR) in 306 and 298 KUU, and discordant findings in 27 and 31 KUU (between the first and second and between first and third cycles), respectively. Therefore, the agreement was 93.5 and 92.5% between the first and second cycles (p = 0.70) and between the first and the third cycles (p = 0.15), respectively. Conclusion: Both the cyclic nature of this study and the results indicated that VCUG without real-time fluoroscopic monitoring could be used where adequate fluoroscopic examination is not possible for children in whom VUR detection is necessary and impacts treatment. However, the responsibility of pediatric radiologist always must also include the task to provide proper equipment for imaging children with suspected VUR.

  4. Automated quantification of lumbar vertebral kinematics from dynamic fluoroscopic sequences

    Camp, Jon; Zhao, Kristin; Morel, Etienne; White, Dan; Magnuson, Dixon; Gay, Ralph; An, Kai-Nan; Robb, Richard


    We hypothesize that the vertebra-to-vertebra patterns of spinal flexion and extension motion of persons with lower back pain will differ from those of persons who are pain-free. Thus, it is our goal to measure the motion of individual lumbar vertebrae noninvasively from dynamic fluoroscopic sequences. Two-dimensional normalized mutual information-based image registration was used to track frame-to-frame motion. Software was developed that required the operator to identify each vertebra on the first frame of the sequence using a four-point "caliper" placed at the posterior and anterior edges of the inferior and superior end plates of the target vertebrae. The program then resolved the individual motions of each vertebra independently throughout the entire sequence. To validate the technique, 6 cadaveric lumbar spine specimens were potted in polymethylmethacrylate and instrumented with optoelectric sensors. The specimens were then placed in a custom dynamic spine simulator and moved through flexion-extension cycles while kinematic data and fluoroscopic sequences were simultaneously acquired. We found strong correlation between the absolute flexionextension range of motion of each vertebra as recorded by the optoelectric system and as determined from the fluoroscopic sequence via registration. We conclude that this method is a viable way of noninvasively assessing twodimensional vertebral motion.

  5. Intraoperative fluoroscopic dose assessment in prostate brachytherapy patients.

    Reed, Daniel R; Wallner, Kent E; Narayanan, Sreeram; Sutlief, Steve G; Ford, Eric C; Cho, Paul S


    To evaluate a fluoroscopy-based intraoperative dosimetry system to guide placement of additional sources to underdosed areas, and perform computed tomography (CT) verification. Twenty-six patients with prostate carcinoma treated with either I-125 or Pd-103 brachytherapy at the Puget Sound VA using intraoperative postimplant dosimetry were analyzed. Implants were performed by standard techniques. After completion of the initial planned brachytherapy procedure, the initial fluoroscopic intraoperative dose reconstruction analysis (I-FL) was performed with three fluoroscopic images acquired at 0 (AP), +15, and -15 degrees. Automatic seed identification was performed and the three-dimensional (3D) seed coordinates were computed and imported into VariSeed for dose visualization. Based on a 3D assessment of the isodose patterns additional seeds were implanted, and the final fluoroscopic intraoperative dose reconstruction was performed (FL). A postimplant computed tomography (CT) scan was obtained after the procedure and dosimetric parameters and isodose patterns were analyzed and compared. An average of 4.7 additional seeds were implanted after intraoperative analysis of the dose coverage (I-FL), and a median of 5 seeds. After implantation of additional seeds the mean V100 increased from 89% (I-FL) to 92% (FL) (p sources to supplement inadequately dosed areas within the prostate gland. Additionally, guided implantation of additional source, can significantly improve V100s and D90s, without significantly increasing rectal doses.

  6. Patient Doses in Paediatric Fluoroscopic Examinations in Finland

    Servomaa, A.; Komppa, T.; Heikkila, M.; Parviainen, T


    Dose-area products (DAP) in paediatric fluoroscopic examinations were measured at paediatric clinics in three university hospitals. The purpose was to provide supplementary data for development of reference doses, and for determination of relations between patient size and dose, in examinations involving both radiography and fluoroscopy for paediatric patients of various ages. The number of paediatric patients was 217. The most common fluoroscopic examinations were: micturating cystourethrography (MCU), 103 patients; barium enema (anography), 39 patients; barium meal and follow, 20 patients; and oesophagus, nine patients. Data on the patients and examination techniques, and the dose-area products are reported for various examinations and age groups. In the MCU examinations the mean DAP values were 560{sup 2} for the age group of 0 years: 910{sup 2} for the age group of 1-4 years; 880{sup 2} for the age group of 5-9 years; and 4600{sup 2} for the age group of 10-15 years. The radiation doses to which paediatric patients are exposed in fluoroscopic examinations vary over a large scale, even within narrow age bands, and comparisons between the doses are difficult because of wide ranges in patient size. This indicates the need for developing a method for taking account of the effects of patients size before deriving reference doses. (author)

  7. Intrapelvic obturator internus muscle injections: a novel fluoroscopic technique.

    Valovska, Assia; Zaccagnino, Michael P; Weaver, Michael J; Valovski, Ivan; Kaye, Alan David; Urman, Richard D


    The obturator internus (OI) muscle is important in adult chronic noninfectious pelvic, perineal, gluteal, and retrotrochanteric pain syndromes. Evaluation and management of these patients' pain can be challenging because of the complex anatomy of this region, broad differential diagnosis, and lack of specific physical examination findings. Consequently, several clinicians have advocated the use of image guided injections to assist in the accurate diagnosis of OI-related symptoms and provide symptomatic relief to affected patients. We present 2 case series describing a novel fluoroscopically guided contrast controlled transpectineal approach to intrapelvic OI injections. Unlike prior fluoroscopically guided OI injection techniques, the approach described in the present 2 cases utilized multiple standard pelvic views, thus facilitating optimal needle positioning in three-dimensional space. This technique utilized standard fluoroscopic pelvic views to accurately measure needle depth within the pelvic cavity permitting the bulk of the OI to be injected in a controlled and safe fashion. The first patient underwent a left intrapelvic OI muscle injection with bupivacaine 0.25% and 40 mg methylprednisolone. The average pre- and postprocedural visual analog pain scale scores were 5 out of 10 and 2 out of 10, respectively, with a self-reported 75% pain reduction. The second patient underwent a right intrapelvic OI muscle injection with bupivacaine 0.25% and 40 mg methylprednisolone. The average pre- and postprocedural visual analog scale scores were 8 out of 10 and 1 out of 10, respectively, with a self-reported 90% pain reduction. Larger scale studies should be undertaken to evaluate the therapeutic efficacy and generalized accuracy of this technique.

  8. Multimodality calibration for simultaneous fluoroscopic and nuclear imaging

    Beijst, Casper; Elschot, Mattijs; van der Velden, Sandra; de Jong, Hugo W A M


    Background Simultaneous real-time fluoroscopic and nuclear imaging could benefit image-guided (oncological) procedures. To this end, a hybrid modality is currently being developed by our group, by combining a c-arm with a gamma camera and a four-pinhole collimator. Accurate determination of the system parameters that describe the position of the x-ray tube, x-ray detector, gamma camera, and collimators is crucial to optimize image quality. The purpose of this study was to develop a calibratio...

  9. The fluoroscopic barium enema in colonic polyp detection.

    Teefey, S A; Carlson, H C


    The results of 1,500 barium enema studies done by vigorous manual palpation under fluoroscopy were reviewed to determine the adequacy of this technique in detecting polyps above the proctoscopic level. Of the 1,500 patients examined, 103 (7%) were diagnosed radiographically as having a total of 149 polyps. Polyps were found at proctoscopy in about 10% of the 1,500 patients. Colonoscopy or surgery was performed on 35 of the 103 patients. Of the 52 polyps discovered during these procedures, only three were missed at fluoroscopic barium enema study, a false-negative rate of 6%. Fourteen patients whose barium enemas initially were reported as negative for polyps or neoplasia had colonoscopy. Two of the 14 patients had positive findings, for a true-negative rate of 86%. If the detection rate of 7% found at barium enema, taking into account an overlap of 10%, is combined with the rate of 7.5% found at proctoscopy, a frequency of about 14% emerges in detecting polyps in the rectum and in the colon. Thus, the fluoroscopic barium enema when combined with proctoscopy is a sensitive method in the detection of colorectal polyps. In addition, it has the advantage of rapid execution and relatively low cost.

  10. Auto-shape lossless compression of pharynx and esophagus fluoroscopic images.

    Arif, Arif Sameh; Mansor, Sarina; Logeswaran, Rajasvaran; Karim, Hezerul Abdul


    The massive number of medical images produced by fluoroscopic and other conventional diagnostic imaging devices demand a considerable amount of space for data storage. This paper proposes an effective method for lossless compression of fluoroscopic images. The main contribution in this paper is the extraction of the regions of interest (ROI) in fluoroscopic images using appropriate shapes. The extracted ROI is then effectively compressed using customized correlation and the combination of Run Length and Huffman coding, to increase compression ratio. The experimental results achieved show that the proposed method is able to improve the compression ratio by 400 % as compared to that of traditional methods.

  11. Fluoroscope Study of Lesser Snow Geese at Sabine National Wildlife Refuge, Louisiana

    US Fish and Wildlife Service, Department of the Interior — This dataset contains the results of a fluoroscope study of Lesser Snow Geese wintering at Sabine National Wildlife Refuge in November of 1974.

  12. The AAPM/RSNA physics tutorial for residents: general overview of fluoroscopic imaging.

    Schueler, B A


    Fluoroscopy is used to visualize the motion of internal fluids, structures, and devices. During a fluoroscopic examination, the operator controls activation of the x-ray tube for real-time imaging of the patient. The article provides a general overview of fluoroscopic imaging from its initial development to modern use. Early fluoroscopes produced a dim image on a fluorescent screen that required dark adaptation of the physician's eyes to optimize viewing conditions. Image intensifiers were later developed to replace the fluorescent screen and increase image brightness. Modern fluoroscopy systems include an image intensifier with television image display and a choice of several different types of image recording devices. Fluoroscopic equipment is available in many different configurations for use in a wide variety of clinical applications.

  13. Minimizing radiation dose to patient and staff during fluoroscopic, nasoenteral tube insertions

    Rudin, S.; Bednarek, D.R. (New York Univ., NY (United States). School of Medicine)


    Since the fluoroscopic image during nasoenteral tube placements is used for guidance and not for diagnosis, a lower contrast image with increased quantum mottle can be easily tolerated. The three methods to reduce the radiation dose rate investigated consisted of removing camera from the image intensifier output phosphor, and setting the fluoroscopic mA to the minimum value so that the kVp could be maximized. Fluoroscopic frozen video frames of a clinical tube insertion comparing the images with and without the dose-saving techniques are presented. Measurements of the radiation dose rates using a Plexiglas phantom show that the dose for patient and staff during fluoroscopic-guided nasoenteral tube placements can be reduced by over a factor of 10 without significantly adversely affecting the actual placement procedure. (author).

  14. Estimates of diagnostic reference levels for pediatric peripheral and abdominal fluoroscopically guided procedures.

    Strauss, Keith J; Racadio, John M; Johnson, Neil; Patel, Manish; Nachabe, Rami A


    The objective of our study was to survey radiation dose indexes of pediatric peripheral and abdominal fluoroscopically guided procedures from which estimates of diagnostic reference levels (DRLs) can be proposed for both a standard fluoroscope and a novel fluoroscope with advanced image processing and lower radiation dose rates. Radiation dose structured reports were retrospectively collected for 408 clinical pediatric cases: Half of the procedures were performed with a standard imaging technology and half with a novel x-ray technology. Dose-area product (DAP), air Kerma (AK), fluoroscopy time, number of digital subtraction angiography images, and patient mass were collected to calculate and normalize radiation dose indexes for procedures completed with the standard and novel fluoroscopes. The study population was composed of 180 and 175 patients who underwent procedures with the standard and novel technology, respectively. The 21 different types of pediatric peripheral and abdominal interventional procedures produced 408 total studies. Median ages, mass and body mass index, fluoroscopy time per procedure, and total number of recorded images for the standard and novel technologies were not statistically different. The area of the x-ray beams was square at the level of the patient with a dimension of 10-13 cm. The dose reduction achieved with the novel fluoroscope ranged from 18% to 51% of the dose required with the standard fluoroscope. The median DAP and AK patient dose indexes were 0.38 Gy · cm(2) and 4.00 mGy, respectively, for the novel fluoroscope. Estimates of dose indexes of pediatric peripheral and abdominal fluoroscopically guided, clinical procedures should assist in the development of DRLs to foster management of radiation doses of pediatric patients.

  15. Silent aspiration: results of 2,000 video fluoroscopic evaluations.

    Garon, Bernard R; Sierzant, Tess; Ormiston, Charles


    The purpose of this retrospective study of aspiration and the lack of a protective cough reflex at the vocal folds (silent aspiration) was to increase the awareness of nursing staffs of the diagnostic pathology groups associated with silent aspiration. Of the 2,000 patients evaluated in this study, 51% aspirated on the video fluoroscopic evaluation. Of the patients who aspirated, 55% had no protective cough reflex (silent aspiration). The diagnostic pathology groups with the highest rates of silent aspiration were brain cancer, brainstem stroke, head-neck cancer, pneumonia, dementia/Alzheimer, chronic obstructive lung disease, seizures, myocardial infarcts, neurodegenerative pathologies, right hemisphere stroke, closed head injury, and left hemisphere stroke. It is of high concern that the diagnostic groups identified in this research as having the highest risk of silent aspiration be viewed as "red-flag" patients by the nursing staff caring for them. Early nursing dysphagia screens, with close attention to the clinical symptoms associated with silent aspiration, and early referral for formal dysphagia evaluation are stressed.

  16. Ultrasound and fluoroscopic images fusion by autonomous ultrasound probe detection.

    Mountney, Peter; Ionasec, Razvan; Kaizer, Markus; Mamaghani, Sina; Wu, Wen; Chen, Terrence; John, Matthias; Boese, Jan; Comaniciu, Dorin


    New minimal-invasive interventions such as transcatheter valve procedures exploit multiple imaging modalities to guide tools (fluoroscopy) and visualize soft tissue (transesophageal echocardiography (TEE)). Currently, these complementary modalities are visualized in separate coordinate systems and on separate monitors creating a challenging clinical workflow. This paper proposes a novel framework for fusing TEE and fluoroscopy by detecting the pose of the TEE probe in the fluoroscopic image. Probe pose detection is challenging in fluoroscopy and conventional computer vision techniques are not well suited. Current research requires manual initialization or the addition of fiducials. The main contribution of this paper is autonomous six DoF pose detection by combining discriminative learning techniques with a fast binary template library. The pose estimation problem is reformulated to incrementally detect pose parameters by exploiting natural invariances in the image. The theoretical contribution of this paper is validated on synthetic, phantom and in vivo data. The practical application of this technique is supported by accurate results (< 5 mm in-plane error) and computation time of 0.5s.

  17. Dose reduction during fluoroscopic placement of feeding tubes

    Rudin, S.; Bednarek, D.R.; Miller, J.A. (State Univ. of New York, Buffalo (USA))


    By both increasing the optical iris of the video camera and removing the grid in fluoroscopic procedures involved in placement of a Dubbhoff feeding tube, the radiation dose to patients and staff was reduced by five to seven times. An average expected dose to a patient of about 300 mGy per procedure was reduced by two to three times when the grid was removed and by an additional three times when an iris of increased diameter was used. Because Dobbhoff procedures do not involve obtaining a diagnosis, the image degradation was acceptable and did not affect the total exposure times or ability to conduct the procedure. With the grid out, the difference between the mean exposure times of 5.1 minutes in 96 patient studies done with a normal iris opening and 4.0 minutes in 52 studies done with an enlarged iris was not statistically significant. The importance of reducing patient dose is reinforced by the finding that one-third of the patients underwent repeated procedures, accounting for almost 60% of the total.

  18. Measuring radiation dose to patients undergoing fluoroscopically-guided interventions

    Lubis, L. E.; Badawy, M. K.


    The increasing prevalence and complexity of fluoroscopically guided interventions (FGI) raises concern regarding radiation dose to patients subjected to the procedure. Despite current evidence showing the risk to patients from the deterministic effects of radiation (e.g. skin burns), radiation induced injuries remain commonplace. This review aims to increase the awareness surrounding radiation dose measurement for patients undergoing FGI. A review of the literature was conducted alongside previous researches from the authors’ department. Studies pertaining to patient dose measurement, its formalism along with current advances and present challenges were reviewed. Current patient monitoring techniques (using available radiation dosimeters), as well as the inadequacy of accepting displayed dose as patient radiation dose is discussed. Furthermore, advances in real-time patient radiation dose estimation during FGI are considered. Patient dosimetry in FGI, particularly in real time, remains an ongoing challenge. The increasing occurrence and sophistication of these procedures calls for further advances in the field of patient radiation dose monitoring. Improved measuring techniques will aid clinicians in better predicting and managing radiation induced injury following FGI, thus improving patient care.

  19. Patient doses from fluoroscopically guided cardiac procedures in pediatrics

    Martinez, L. C.; Vano, E.; Gutierrez, F.; Rodriguez, C.; Gilarranz, R.; Manzanas, M. J.


    Infants and children are a higher risk population for radiation cancer induction compared to adults. Although some values on pediatric patient doses for cardiac procedures have been reported, data to determine reference levels are scarce, especially when compared to those available for adults in diagnostic and therapeutic procedures. The aim of this study is to make a new contribution to the scarce published data in pediatric cardiac procedures and help in the determination of future dose reference levels. This paper presents a set of patient dose values, in terms of air kerma area product (KAP) and entrance surface air kerma (ESAK), measured in a pediatric cardiac catheterization laboratory equipped with a biplane x-ray system with dynamic flat panel detectors. Cardiologists were properly trained in radiation protection. The study includes 137 patients aged between 10 days and 16 years who underwent diagnostic catheterizations or therapeutic procedures. Demographic data and technical details of the procedures were also gathered. The x-ray system was submitted to a quality control programme, including the calibration of the transmission ionization chamber. The age distribution of the patients was 47 for <1 year; 52 for 1-<5 years; 25 for 5-<10 years and 13 for 10-<16 years. Median values of KAP were 1.9, 2.9, 4.5 and 15.4 Gy cm2 respectively for the four age bands. These KAP values increase by a factor of 8 when moving through the four age bands. The probability of a fatal cancer per fluoroscopically guided cardiac procedure is about 0.07%. Median values of ESAK for the four age bands were 46, 50, 56 and 163 mGy, which lie far below the threshold for deterministic effects on the skin. These dose values are lower than those published in previous papers.

  20. Inferring 3D kinematics of carpal bones from single view fluoroscopic sequences.

    Chen, Xin; Graham, Jim; Hutchinson, Charles; Muir, Lindsay


    We present a novel framework for inferring 3D carpal bone kinematics and bone shapes from a single view fluoroscopic sequence. A hybrid statistical model representing both the kinematics and shape variation of the carpal bones is built, based on a number of 3D CT data sets obtained from different subjects at different poses. Given a fluoroscopic sequence, the wrist pose, carpal bone kinematics and bone shapes are estimated iteratively by matching the statistical model with the 2D images. A specially designed cost function enables smoothed parameter estimation across frames. We have evaluated the proposed method on both simulated data and real fluoroscopic sequences. It was found that the relative positions between carpal bones can be accurately estimated, which is potentially useful for detection of conditions such as scapholunate dissociation.

  1. A feasibility study of markerless fluoroscopic gating for lung cancer radiotherapy using 4DCT templates

    Li Ruijiang; Lewis, John H; Cervino, Laura I; Jiang, Steve B [Department of Radiation Oncology, University of California San Diego, 3855 Health Sciences Dr, La Jolla, CA 92037-0843 (United States)], E-mail:


    A major difficulty in conformal lung cancer radiotherapy is respiratory organ motion, which may cause clinically significant targeting errors. Respiratory-gated radiotherapy allows for more precise delivery of prescribed radiation dose to the tumor, while minimizing normal tissue complications. Gating based on external surrogates is limited by its lack of accuracy, while gating based on implanted fiducial markers is limited primarily by the risk of pneumothorax due to marker implantation. Techniques for fluoroscopic gating without implanted fiducial markers (markerless gating) have been developed. These techniques usually require a training fluoroscopic image dataset with marked tumor positions in the images, which limits their clinical implementation. To remove this requirement, this study presents a markerless fluoroscopic gating algorithm based on 4DCT templates. To generate gating signals, we explored the application of three similarity measures or scores between fluoroscopic images and the reference 4DCT template: un-normalized cross-correlation (CC), normalized cross-correlation (NCC) and normalized mutual information (NMI), as well as average intensity (AI) of the region of interest (ROI) in the fluoroscopic images. Performance was evaluated using fluoroscopic and 4DCT data from three lung cancer patients. On average, gating based on CC achieves the highest treatment accuracy given the same efficiency, with a high target coverage (average between 91.9% and 98.6%) for a wide range of nominal duty cycles (20-50%). AI works well for two patients out of three, but failed for the third patient due to interference from the heart. Gating based on NCC and NMI usually failed below 50% nominal duty cycle. Based on this preliminary study with three patients, we found that the proposed CC-based gating algorithm can generate accurate and robust gating signals when using 4DCT reference template. However, this observation is based on results obtained from a very limited

  2. Pre-procedural scout radiographs are unnecessary for routine pediatric fluoroscopic examinations

    Creeden, Sean G.; Rao, Anil G.; Eklund, Meryle J.; Hill, Jeanne G.; Thacker, Paul G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States)


    Although practice patterns vary, scout radiographs are often routinely performed with pediatric fluoroscopic studies. However few studies have evaluated their utility in routine pediatric fluoroscopy. To evaluate the value of scout abdomen radiographs in routine barium or water-soluble enema, upper gastrointestinal (GI) series, and voiding cystourethrogram pediatric fluoroscopic procedures. We retrospectively evaluated 723 barium or water-soluble enema, upper GI series, and voiding cystourethrogram fluoroscopic procedures performed at our institution. We assessed patient history and demographics, clinical indication for the examination, prior imaging findings and impressions, scout radiograph findings, additional findings provided by the scout radiograph that were previously unknown, and whether the scout radiograph contributed any findings that significantly changed management. We retrospectively evaluated 723 fluoroscopic studies (368 males and 355 females) in pediatric patients. Of these, 700 (96.8%) had a preliminary scout radiograph. Twenty-three (3.2%) had a same-day radiograph substituted as a scout radiograph. Preliminary scout abdomen radiographs/same-day radiographs showed no new significant findings in 719 (99.4%) studies. New but clinically insignificant findings were seen in 4 (0.6%) studies and included umbilical hernia, inguinal hernia and hip dysplasia. No findings were found on the scout radiographs that would either alter the examination performed or change management with regard to the exam. Pre-procedural scout abdomen radiographs are unnecessary in routine barium and water-soluble enema, upper GI series, and voiding cystourethrogram pediatric fluoroscopic procedures and can be substituted with a spot fluoroscopic last-image hold. (orig.)

  3. Spinal cord injury from fluoroscopically guided intercostal blocks with phenol.

    Kissoon, Narayan R; Graff-Radford, Jonathan; Watson, James C; Laughin, Ruple S


    Image guided intercostal blocks are commonly performed and considered relatively safe. Chemical denervation is commonly used in clinical practice for treatment of chronic non-cancer associated pain. To report a case of spinal cord injury resulting from fluoroscopically guided intercostal blocks with phenol. Case report. Inpatient hospital service. RESULTS/CASE REPORTS: A 53 year-old women was transferred from her local facility for acute onset of lower extremity paresis beginning shortly after right intercostal nerve injections of 2 mL of preservative-free phenol at the T7, 8, 9 levels. She had previous intercostal blocks for chronic right-sided mid thoracic/abdominal pain every 3 months for at least one year without sequelae. Within 20 minutes of the injection, she developed a sensation of right leg weakness and heaviness. Over several hours she developed worsening right leg weakness, and then left leg weakness, followed by urinary retention. Admission examination revealed severe right greater than left leg weakness, right lower extremity hyperesthesia to T10, absent lower extremity reflexes, and bilateral extensor plantar responses. Magnetic resonance imaging (MRI) of the entire spine demonstrated extensive T2/DWI hyperintensity in the central spinal cord from T1 to L1 with mild cord enlargement and enhancement at T7-9 (sites of injection). Extensive serum and cerebrospinal fluid (CSF) evaluation did not show any evidence of an infectious, inflammatory, or metabolic cause to her myelopathy. Repeat MRI of the entire spine demonstrated near complete resolution of the T2 signal abnormality. One month after presentation, despite radiographic improvement, the patient showed some clinical improvement, but remained walker dependent and with neurogenic bowel and bladder. This report describes a single case report. This case offers several lessons for a pain specialist including 1) the potential for a neurologic catastrophe (spinal cord injury) from aqueous neurolytic

  4. RADCOM: a computerized translation device for use during fluoroscopic examination of non-English-speaking patients.

    Cohn, M J; Cohen, A J


    We developed and have implemented RADCOM (RADiology COMmunicator), a computerized speech-based language translator for use during fluoroscopic examination of non-English-speaking patients. It is controlled completely by voice commands issued into a headset microphone. The system output is digital audio via a small speaker, in the native language of the patient. RADCOM currently supports more than 40 commands in more than a dozen languages. The language data base is easily expandable. We have performed more than 20 fluoroscopic examinations with the RADCOM system. The non-English-speaking patients respond well, following the selected instructions appropriately.

  5. Technique for Percutaneous Fluoroscopically Guided G-Tube Placement in a High-BMI Patient

    Irwin M. Best


    Full Text Available Enteral feeding is still the preferred method of nutritional support even in patients with excessive body mass index. Often, this mass poses a hindrance in performing routine procedures. We present a case describing the technique used to safely place a fluoroscopically guided G-tube in a patient with a significant nutritional deficit after repair of a ruptured thoracic aneurysm. Her admission weight was in excess of 180 Kg. However, protracted respiratory insufficiency and mechanical ventilation prolonged her hospital course. The G-tube was successfully placed using a fluoroscopically guided technique. The advantages of such an approach are discussed.

  6. Technique for Percutaneous Fluoroscopically Guided G-Tube Placement in a High-BMI Patient.

    Best, Irwin M


    Enteral feeding is still the preferred method of nutritional support even in patients with excessive body mass index. Often, this mass poses a hindrance in performing routine procedures. We present a case describing the technique used to safely place a fluoroscopically guided G-tube in a patient with a significant nutritional deficit after repair of a ruptured thoracic aneurysm. Her admission weight was in excess of 180 Kg. However, protracted respiratory insufficiency and mechanical ventilation prolonged her hospital course. The G-tube was successfully placed using a fluoroscopically guided technique. The advantages of such an approach are discussed.

  7. 28 CFR 552.13 - X-ray, major instrument, fluoroscope, or surgical intrusion.


    ... INSTITUTIONAL MANAGEMENT CUSTODY Searches of Housing Units, Inmates, and Inmate Work Areas § 552.13 X-ray, major... 28 Judicial Administration 2 2010-07-01 2010-07-01 false X-ray, major instrument, fluoroscope, or... reasons only, with the inmate's consent. (b) The institution physician may authorize use of an X-ray...

  8. Combined CT and fluoroscopic guidance of balloon kyphoplasty versus fluoroscopy-only procedures

    Amoretti, Nicolas; Marcy, Pierre-Yves; Lesbats-Jacquot, Virginie; Fonquerne, Marie-Eve; Hericord, Olivier; Maratos, Yvonne [Centre Hospitalier Universitaire de Nice, Service de Radiologie, Nice (France); Hovorka, Istvan [Centre Hospitalier Universitaire de Nice, Spine Surgery Department, Nice (France); Roux, Christian; Euller-Ziegler, Liana [Centre Hospitalier Universitaire de Nice, Rheumatology Department, Nice (France)


    To evaluate the performance of combined (computed tomography (CT) and fluoroscopic) guidance of balloon kyphoplasty in comparison to fluoroscopic guidance alone. Forty-one kyphoplasties were performed between January 2005 and March 2006 according to two different protocols. Study group 1 consisted of 20 consecutive patients with 20 balloon kyphoplasty procedures under dual guidance (CT scan and fluoroscopy) for osteoporotic or traumatic vertebral fractures. Study group 2 consisted of 21 consecutive patients in whom kyphoplasty was performed with fluoroscopy alone. Visualization of the pedicles, the final of the balloon position, and cement distribution were evaluated(1 - poor, 2 - intermediate, 3 - good). Combined use of CT and fluoroscopy (group 1) was superior in identifying the pedicles (100% versus 66.7%, p = 0.009) and balloon placement (100% versus 71.4%, p = 0.02) but not in monitoring of cement distribution within the vertebral body (100% versus 90.5%, p = 0.49). The difference between the two groups was more pronounced in the thoracic spine than in the lumbar spine. CT/fluoroscopic guidance of kyphoplasty combines safe CT-guided insertion of the osteointroducers and balloons as well as fluoroscopic real-time monitoring of polymethylmethacrylate injection. (orig.)

  9. Transcatheter Mitral Paravalvular Leak Closure Facilitated by Preprocedural Cardiac CT for Simulation of Fluoroscopic Anatomy and Paravalvular Defect Localization.

    Korsholm, Kasper; Mortensen, Ulrik; Jensen, Jesper Møller; Piazza, Nicolo; Thériault-Lauzier, Pascal; Nielsen-Kudsk, Jens Erik


    Paravalvular leakage (PVL) occurs in 6%-15% of cases after surgical heart valve replacement. A percutaneous approach is increasingly used to close PVLs as an alternative to repeat surgery. Computed tomography (CT) can be used for simulation of fluoroscopic cardiac anatomy. This technique allows preprocedural definition of optimal C-arm angulations and PVL localization in reference to fluoroscopic views. It is very helpful for guidewire crossing of the PVL and positioning of the closure device. We report a case with the first use of dedicated software for fluoroscopic simulation (FluoroCT) in transcatheter mitral PVL closure.

  10. MR cone-beam CT fusion image overlay for fluoroscopically guided percutaneous biopsies in pediatric patients.

    Thakor, Avnesh S; Patel, Premal A; Gu, Richard; Rea, Vanessa; Amaral, Joao; Connolly, Bairbre L


    Lesions only visible on magnetic resonance (MR) imaging cannot easily be targeted for image-guided biopsy using ultrasound or X-rays but instead require MR guidance with MR-compatible needles and long procedure times (acquisition of multiple MR sequences). We developed an alternative method for performing these difficult biopsies in a standard interventional suite, by fusing MR with cone-beam CT images. The MR cone-beam CT fusion image is then used as an overlay to guide a biopsy needle to the target area under live fluoroscopic guidance. Advantages of this technique include (i) the ability for it to be performed in a conventional interventional suite, (ii) three-dimensional planning of the needle trajectory using cross-sectional imaging, (iii) real-time fluoroscopic guidance for needle trajectory correction and (iv) targeting within heterogeneous lesions based on MR signal characteristics to maximize the potential biopsy yield.

  11. Aid to Percutaneous Renal Access by Virtual Projection of the Ultrasound Puncture Tract onto Fluoroscopic Images

    Mozer, Pierre; Leroy, Antoine; Baumann, Michael; Payan, Yohan; Troccaz, Jocelyne; Chartier-Kastler, Emmanuel; Richard, François


    Background and Purpose: Percutaneous renal access in the context of percutaneous nephrolithotomy (PCNL) is a difficult technique, requiring rapid and precise access to a particular calix. We present a computerized system designed to improve percutaneous renal access by projecting the ultrasound puncture tract onto fluoroscopic images. Materials and Methods: The system consists of a computer and a localizer allowing spatial localization of the position of the various instruments. Without any human intervention, the ultrasound nephrostomy tract is superimposed in real time onto fluoroscopic images acquired in various views. Results: We tested our approach by laboratory experiments on a phantom. Also, after approval by our institution's Ethics Committee, we validated this technique in the operating room during PCNL in one patient. Conclusion: Our system is reliable, and the absence of image-processing procedures makes it robust. We have initiated a prospective study to validate this technique both for PCNL speci...

  12. Video-fluoroscopic study of swallowing in children with neurodevelopmental disorders.

    Fung, Cheuk-Wing; Khong, Pek-Lan; To, Raymond; Goh, Winnie; Wong, Virginia


    Children with neurodevelopmental disorders can have feeding problems. Malnutrition and recurrent aspiration pneumonia can increase the risk of morbidity and mortality. Video-fluoroscopic study of swallowing (VFSS) is essential in understanding the pathological mechanisms involved during swallowing. The aim of the present study was to assess the role of VFSS in assessment and management of four children with various neurodevelopmental disorders in a multidisciplinary feeding team. We describe the team approach, with the participation of child neurologist, radiologist with the rehabilitation team including the speech therapist, occupational therapist and dietician, in the assessment and plan of management. Video-fluoroscopic study of swallowing had been useful in assessing the type of swallowing problems with treatment goals targeted to the basic underlying pathophysiological mechanism. A child neurologist should be involved in the multidisciplinary oromotor rehabilitation program for neurologically impaired children with feeding problems.

  13. Foreign body extraction from soft tissue by using CT and fluoroscopic guidance: a new technique

    Amoretti, Nicolas; Marcy, Pierre-Yves; Lesbats-Jacquot, Virginie; Fonquerne, Marie-Eve; Maratos, Yvonne [Centre Hospitalier Universitaire de Nice, Radiology Department, Nice (France); Hauger, Olivier [Hopital Pellegrin, Unite d' Imagerie Osteo-articulaire, CHU de Bordeaux (France); Hovorka, Istvan; Boileau, Pascal [Centre Hopitalier Universitaire de Nice, Orthopaedic Department, Nice (France)


    We report on a new minimally invasive technique for the retrieval of a surgical pin fragment after accidental migration into the soft tissue of the shoulder in two patients. The technique is performed under local anaesthesia and uses combined CT and fluoroscopic guidance. The materials used were simple, combining a bone biopsy needle and an endoscopy clamp. Pin displacement was confirmed under fluoroscopic guidance and the clamp was used to withdraw the pin to the cutaneous entry point under CT (step-by-step) guidance. The CT slices provide perfect visualisation of the vascular or nervous structures as well as perfect positioning of the extremity of the trocar relative to the material to be removed. This intervention avoids a second surgical intervention with a longer incision and avoided repeated general anaesthesia. (orig.)

  14. Use of a fluoroscopic overlay to assist arthroscopic anterior cruciate ligament reconstruction.

    Moloney, Gele; Araujo, Paulo; Rabuck, Stephen; Carey, Robert; Rincon, Gustavo; Zhang, Xudong; Harner, Christopher


    A growing body of evidence supports the importance of anatomic tunnel positioning in the success of anterior cruciate ligament (ACL) reconstruction, which stimulates the need for technologies to aid surgeons in achieving accurate anatomic tunnel placement. Intraoperative fluoroscopy is potentially one such technology, while its efficacy and usability have yet to be established. To investigate the performance of an intraoperative fluoroscopic overlay in guiding tunnel placement during ACL reconstruction. Controlled laboratory study. Twenty cadaveric knees underwent computed tomography (CT) scans and arthroscopic digitization of ACL insertion sites. The outlines of the digitized insertion sites were mapped to the corresponding CT-acquired bone models through a co-registration procedure. Twenty orthopaedic surgeons performed simulated ACL reconstructions, each on a randomly assigned cadaveric knee, first without and then with the aid of a fluoroscopic overlay system. The overlay system displayed on a lateral fluoroscopic image targets points representing the locations of the ACL insertion sites estimated from the literature data. Surgeons were allowed to adjust their tunnel positions under the guidance of the fluoroscopic image. Their initial, intermediate, and final positions were documented and compared with the target points as well as the native insertion sites. Surgeons demonstrated significant (P < .01) improvements in femoral and tibial tunnel placements relative to the target points from an average distance of 3.9 mm to 1.6 mm on the femur and 2.1 mm to 0.9 mm on the tibia. The improvements toward the knee-specific actual insertion sites were significant on the tibial side but not on the femoral side. Surgeons can be successfully guided with fluoroscopy to create more consistent femoral and tibial tunnels during ACL reconstruction. More research is warranted to develop better population representations of the locations of natural insertion sites

  15. R&D of the Fluoroscopes of 100 MeV Cyclotron Beam Lines

    YIN; Meng; GUAN; Feng-ping; XIE; Huai-dong; ZHENG; Xia; XING; Jian-sheng; LV; Yin-long


    Beijing Radioactive Ion-beam Facility(BRIF)consists of a 100 MeV H-cyclotron CYCIAE-100and nine beam lines.All the beam lines provide the channels of the proton beam or the neutron beam to the terminal of physics experiment.There are many beam diagnosis monitors distributing along the beam lines,including,Faraday cups,beam position monitors,fluoroscopes,collimators,emittance measurement

  16. Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

    Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark [Kosin Medical College, Pusan (Korea, Republic of)


    To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis.

  17. Long term safety of fluoroscopically guided selective salpingography and tubal catheterization.

    Papaioannou, S; Afnan, M; Coomarasamy, A; Ola, B; Hammadieh, N; Temperton, D H; McHugo, J M; Sharif, K


    The irradiation of the ovaries of reproductive age women during fluoroscopically guided selective salpingography and tubal catheterization has raised concern about the safety of the procedure. In addition to the risk of cancer induction, which exists with the irradiation of all tissues, with the gonads, the induction of hereditary disorders is possible. The objective of this study was to estimate these risks and present them in a clinically meaningful way. Retrospective analysis was undertaken of 366 consecutive cases of selective salpingography and tubal catheterization performed at the Birmingham Women's Hospital, UK. The radiation doses of different types of procedure were compared with the background annual radiation dose. The risks of cancer and genetic disorders induction were calculated using conversion coefficients published by the International Commission on Radiological Protection. The radiation dose women were exposed to during selective salpingography and tubal catheterization under fluoroscopic guidance was a fraction of the background annual radiation dose. The excess lifetime risks of cancer and hereditary disorders were in the order of four to 13 and two to six per million procedures respectively. The long term risks of selective salpingography and tubal catheterization under fluoroscopic guidance are low.

  18. Percutaneous drainage of psoas abscess under real-time computed tomography fluoroscopic guidance

    Yamagami, Takuji; Terayama, Koshi; Yoshimatsu, Rika; Matsumoto, Tomohiro; Miura, Hiroshi; Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science, Kyoto (Japan)


    The goal of our study was to determine the usefulness of percutaneous abscess drainage under guidance of computed tomography (CT) fluoroscopy. Our subjects were 21 patients (seven women, 14 men; mean age 64 years; age range 30-87 years) who had undergone percutaneous drainage of 26 psoas abscess lesions under CT fluoroscopic guidance between May 2001 and January 2008. Drainage methods involved a needle puncture, insertion of a guidewire, serial dilations, and the exchange of the needle with a drainage tube. The procedures were guided by use of a helical CT scanner that provided real-time fluoroscopic reconstruction. Percutaneous drainage under real-time CT fluoroscopic guidance was successfully performed in every procedure. Use of real-time CT fluoroscopy allowed rapid assessment of needle, guidewire, and catheter placement. No patient had serious complications related to the drainage procedure. The mean procedure time required to drain one lesion was 35.6 {+-} 13.6 min. Mean period after the drainage procedure until complete disappearance of the abscess as confirmed by CT was 12.4 {+-} 10.0 days (range 3-46 days). CT fluoroscopy is useful in achieving accurate and safe drainage of abnormal psoas fluid collections. (orig.)

  19. Percutaneous Drainage of Postoperative Pelvic Abscess: Fluoroscopic and US-Guided Transgluteal Approach

    Lim, Hyo Jin; Hong, Hyun Pyo; Lee, Hyung Geun; Choi, Yoon Jung; Lee, Young Rae; Lee, Ji Young; Park, Hae Won [Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Sam Soo [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)


    To retrospectively review the effectiveness and safety of fluoroscopic and US-guided percutaneous transgluteal drainage of postoperative pelvic abscesses. From January 2002 to December 2007, 594 patients underwent surgery at our institution due to rectosigmoid cancer. A retrospective analysis revealed that percutaneous drainage of a postoperative pelvic abscess was performed in 19 out of the 594 patients (3.19%) that underwent surgery (13 male, 6 female; mean age, 57.9 years; age range, 40-82 years). The transgluteal and other methods were used for percutaneous drainage and the success rate, duration of therapy, and complication rate were evaluated. The transgluteal approach was performed with fluoroscopic and US-guidance in 10 patients (52.6%). A catheter was inserted through a preexisting surgical drain in 5 patients (26.3%). The transabdominal approach was performed under US-guidance in 4 patients (21.0%). Technical success was achieved in all patients. The catheter was removed after a mean of 14 days. In 2 patients, who were treated by the transgluteal approach, subsequent surgery was performed due to incomplete resolution of the abscess (10.5%). The mean duration of catheter drainage using the transgluteal approach (16.5 days) was longer than other methods (11.2 days). Furthermore, no procedure-related major complications or mortality was observed in all methods. The percutaneous transgluteal approach to a postoperative pelvic abscess with US and fluoroscopic guidance is relatively safe and effective.

  20. Transthoracic fine needle aspiration biopsy of subcarinal lesion: oblique approach using biplane fluoroscopic guidance

    Kim, Sung Tae; Jeon, Seok Chol; Choi, Yo Won; Seo, Heung Suk; Hahm, Chang Kok [School of Medicine, Hanyang University, Seoul (Korea, Republic of)


    To evaluate effectiveness of oblique approach under biplane fluoroscopic guidance in transthoracic fine needle aspiration biopsy. Fourteen consecutive patients underwent transthoracic fine needle aspiration biopsy for subcarinal lesions. Subcarina was the only accessible biopsy site in 13 patients. Subcarinal biopsy was performed to determine the presence of metastasis in an enlarged subcarinal lymph node in the remaining one patient. Before biopsy, we evaluated the size and location of the lesion on preliminary plain chest X-ray film and CT scan. Under dual projection fluoroscopic guidance, biopsy was performed through right posterior intercostal space with the patient prone by using oblique approach. On 15 degree LAO projection the needle was directed to the area anterior to the spine and advanced to the line extending through the posterior wall of the main bronchus. Cytologic diagnosis was made in 12 out of 14 patients(accuracy 85.7%). The final diagnosis consisted of 5 squamous cell carcinoma, 5 small cell carcinoma, 1 adenocarcinoma and 1 adenosquamous carcinoma. Pneumothorax developed in 2 patients(14%) and was managed by chest tube drainage. Mild hemoptysis was observed in 2. Transthoracic fine needle aspiration biopsy using oblique approach under biplane fluoroscopic guidance is a relatively safe and sensitive method for the histologic diagnosis of subcarinal lesion.

  1. A spatio-temporal detective quantum efficiency and its application to fluoroscopic systems

    Friedman, S. N.; Cunningham, I. A. [Sackler School of Medicine, Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978 (Israel); Imaging Research Laboratories, Robarts Research Institute and Lawson Health Research Institute, 100 Perth Drive, London, Ontario N6A 5K8 (Canada) and Department of Medical Biophysics, University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B8 (Canada)


    Purpose: Fluoroscopic x-ray imaging systems are used extensively in spatio-temporal detection tasks and require a spatio-temporal description of system performance. No accepted metric exists that describes spatio-temporal fluoroscopic performance. The detective quantum efficiency (DQE) is a metric widely used in radiography to quantify system performance and as a surrogate measure of patient ''dose efficiency.'' It has been applied previously to fluoroscopic systems with the introduction of a temporal correction factor. However, the use of a temporally-corrected DQE does not provide system temporal information and it is only valid under specific conditions, many of which are not likely to be satisfied by suboptimal systems. The authors propose a spatio-temporal DQE that describes performance in both space and time and is applicable to all spatio-temporal quantum-based imaging systems. Methods: The authors define a spatio-temporal DQE (two spatial-frequency axes and one temporal-frequency axis) in terms of a small-signal spatio-temporal modulation transfer function (MTF) and spatio-temporal noise power spectrum (NPS). Measurements were made on an x-ray image intensifier-based bench-top system using continuous fluoroscopy with an RQA-5 beam at 3.9 {mu}R/frame and hardened 50 kVp beam (0.8 mm Cu filtration added) at 1.9 {mu}R/frame. Results: A zero-frequency DQE value of 0.64 was measured under both conditions. Nonideal performance was noted at both larger spatial and temporal frequencies; DQE values decreased by {approx}50% at the cutoff temporal frequency of 15 Hz. Conclusions: The spatio-temporal DQE enables measurements of decreased temporal system performance at larger temporal frequencies analogous to previous measurements of decreased (spatial) performance. This marks the first time that system performance and dose efficiency in both space and time have been measured on a fluoroscopic system using DQE and is the first step toward the

  2. A spatio-temporal detective quantum efficiency and its application to fluoroscopic systems.

    Friedman, S N; Cunningham, I A


    Fluoroscopic x-ray imaging systems are used extensively in spatio-temporal detection tasks and require a spatio-temporal description of system performance. No accepted metric exists that describes spatio-temporal fluoroscopic performance. The detective quantum efficiency (DQE) is a metric widely used in radiography to quantify system performance and as a surrogate measure of patient "dose efficiency". It has been applied previously to fluoroscopic systems with the introduction of a temporal correction factor. However, the use of a temporally-corrected DQE does not provide system temporal information and it is only valid under specific conditions, many of which are not likely to be satisfied by suboptimal systems. The authors propose a spatio-temporal DQE that describes performance in both space and time and is applicable to all spatio-temporal quantum-based imaging systems. The authors define a spatio-temporal DQE (two spatial-frequency axes and one temporal-frequency axis) in terms of a small-signal spatio-temporal modulation transfer function (MTF) and spatio-temporal noise power spectrum (NPS). Measurements were made on an x-ray image intensifier-based bench-top system using continuous fluoroscopy with an RQA-5 beam at 3.9 microR/frame and hardened 50 kVp beam (0.8 mm Cu filtration added) at 1.9 microR/frame. A zero-frequency DQE value of 0.64 was measured under both conditions. Nonideal performance was noted at both larger spatial and temporal frequencies; DQE values decreased by approximately 50% at the cutoff temporal frequency of 15 Hz. The spatio-temporal DQE enables measurements of decreased temporal system performance at larger temporal frequencies analogous to previous measurements of decreased (spatial) performance. This marks the first time that system performance and dose efficiency in both space and time have been measured on a fluoroscopic system using DQE and is the first step toward the generalized use of DQE on clinical fluoroscopic systems.

  3. Assessing validation of dual fluoroscopic image matching method for measurement of in vivo spine kinematics

    BAI Jian-qiang; HU Yong-cheng; DU Li-qing; HE Jing-liang; LIU Kai; LIU Zhong-jun; XIA Qun


    Background Accurate knowledge of the spinal structural functions is critical to understand the biomechanical factors that affect spinal pathology. Many studies have investigated the human vertebral motion both in vitro and in vivo.However, determination of in vivo motion of the vertebrae under physiologic loading conditions remains a challenge in biomedical engineering because of the limitations of current technology and the complicated anatomy of the spine.Methods For in vitro validation, a human lumbar specimen was imbedded with steel beads and moved to a known distance by an universal testing machine (UTM). The dual fluoroscopic system was used to capture the spine motion and reproduce the moving distance. For in vivo validation, a living subject moved the spine in various positions while bearing weight. The fluoroscopes were used to reproduce the in vivo spine positions 5 times. The standard deviations in translation and orientation of the five measurements were used to evaluate the repeatability of technique. The accuracy of vertebral outline matching with metallic marks matching technology was compared.Results The translation positions of the human lumbar specimen could be determined with a mean accuracy less than 0.35 mm and a mean repeatability 0.36 mm for the image matching technique. The repeatability of the method in reproducing in vivo human spine six degrees of freedom (6DOF) kinematics was less than 0.43 mm in translation and less than 0.65° in rotation. The accuracy of metallic marks and vertebral outline matching did not show significant difference.Conclusions Combining a dual fluoroscopic and computerized tomography imaging technique was accurate and reproduceable for noninvasive measurement of spine vertebral motion. The vertebral outline matching technique could be a useful technique for matching of vertebral positions and orientations which can evaluate and improve the efficacy of the various surgical treatments.

  4. Pediatric Percutaneous Osteoid Osteoma Ablation: Cone-Beam CT with Fluoroscopic Overlay Versus Conventional CT Guidance.

    Perry, Brandon C; Monroe, Eric J; McKay, Tyler; Kanal, Kalpana M; Shivaram, Giridhar


    To compare technical success, clinical success, complications, radiation dose, and total room utilization time for osteoid osteoma thermal (radiofrequency or microwave) ablation using cone-beam computed tomography (CBCT) with two-axis fluoroscopic navigational overlay versus conventional computed tomography (CT) guidance. A retrospective review was performed to identify all osteoid osteoma ablations performed over a 5.5-year period at a single tertiary care pediatric hospital. Twenty-five ablations (15 radiofrequency and 10 microwave) in 23 patients undergoing fluoroscopic CBCT-guided osteoid osteoma ablation were compared to 35 ablations (35 radiofrequency) in 32 patients undergoing ablation via conventional CT guidance. Dose area product and dose length product were recorded for CBCT and conventional CT, respectively, and converted to effective doses. Technical success, clinical success (cessation of pain and medication use 1 month after ablation), complications, radiation dose, and total room utilization time were compared. All procedures were technically successful. Twenty-two of 25 (88.0%) CBCT and 31 of 35 (88.6%) conventional CT-guided ablations achieved immediate clinical success. There were two minor complications in each group and no major complications. Mean effective radiation dose was significantly lower for CBCT compared to CT guidance (0.12 vs. 0.39 mSv, p = 0.02). Mean total room utilization time for CBCT was longer (133.5 vs. 97.5 min, p = 0.0001). Fluoroscopic CBCT guidance for percutaneous osteoid osteoma ablation yields similar technical and clinical success, reduced radiation dose, and increased total room utilization time compared to conventional CT guidance.

  5. Solid-state fluoroscopic imager for high-resolution angiography: parallel-cascaded linear systems analysis.

    Vedantham, Srinivasan; Karellas, Andrew; Suryanarayanan, Sankararaman


    Cascaded linear systems based modeling techniques have been used in the past to predict important system parameters that have a direct impact on image quality. Such models are also useful in optimizing system parameters to improve image quality. In this work, detailed analysis of a solid-state fluoroscopic imaging system intended for high-resolution angiography is presented with the use of such a model. The imaging system analyzed through this model uses four 8 x 8 cm three-side buttable interlined charge-coupled devices (CCDs) specifically designed for high-resolution angiography and tiled in a seamless fashion to achieve a field of view (FOV) of 16 x 16 cm. Larger FOVs can be achieved by tiling more CCDs in a similar manner. The system employs a CsI:Tl scintillator coupled to the CCDs by straight (nontapering) fiberoptics and can potentially be operated in 78, 156, or 234 microm pixel pitch modes. The system parameters analyzed through this model include presampling modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE). The results of the simulations performed indicate that DQE(0) in excess of 0.6 is achievable, with the imager operating at 156 microm pixel pitch, 30 frames/s, and employing a 450-microm-thick CsI:Tl scintillator, even at a low fluoroscopic exposure rate of 1 microR/frame. Further, at a nominal fluoroscopic exposure rate of 2.5 microR/frame there was no noticeable degradation of the DQE even at the 78 microm pixel pitch mode suggesting that it is feasible to perform high-resolution angiography hitherto unattainable in clinical practice.

  6. Technical and imaging report: fluoroscopic guidance for diagnosis and treatment of lumbar synovial cyst.

    Rauchwerger, Jacob J; Candido, Kenneth D; Zoarski, Gregg H


    Lumbar synovial cysts can be a source of low back pain with or without radiculopathy depending upon the size and location of the mass. Options for treatment range from analgesics to surgery, depending upon the degree of nerve root or spinal cord impingement. Attempts at minimally invasive treatment such as computed tomography-assisted aspiration and cyst rupture are documented in the radiology literature with varying degrees of reported success. This case report is the first to document the fluoroscopically-guided management of a lumbar synovial cyst in the pain medicine literature and highlights the knowledge and technical skills required when treating such cases. © 2010 World Institute of Pain.

  7. C-arm cone beam computed tomography needle path overlay for fluoroscopic guided vertebroplasty.

    Tam, Alda L; Mohamed, Ashraf; Pfister, Marcus; Chinndurai, Ponraj; Rohm, Esther; Hall, Andrew F; Wallace, Michael J


    Retrospective review. To report our early clinical experience using C-arm cone beam computed tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty. C-arm CBCT is advanced three-dimensional (3-D) imaging technology that is currently available on state-of-the-art flat panel based angiography systems. The imaging information provided by C-arm CBCT allows for the acquisition and reconstruction of "CT-like" images in flat panel based angiography/interventional suites. As part of the evolution of this technology, enhancements allowing the overlay of cross-sectional imaging information can now be integrated with real time fluoroscopy. We report our early clinical experience with C-arm CBCT with fluoroscopic overlay for needle guidance during vertebroplasty. This is a retrospective review of 10 consecutive oncology patients who underwent vertebroplasty of 13 vertebral levels using C-arm CBCT with fluoroscopic overlay for needle guidance from November 2007 to December 2008. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Technical success with the overlay technology was assessed based on accuracy which consisted of 4 measured parameters: distance from target to needle tip, distance from planned path to needle tip, distance from midline to needle tip, and distance from the anterior 1/3 of the vertebral body to needle tip. Success within each parameter required that the distance between the needle tip and parameter being evaluated be no more than 5 mm on multiplanar CBCT or fluoroscopy. Imaging data for 12 vertebral levels was available for review. All vertebral levels were treated using unilateral access and 9 levels were treated with an extrapedicular approach. Technical success rates were 92% for both distance from planned path and distance from midline to final needle tip, 100% when distance from needle tip to the anterior 1

  8. Transrectal Drainage of Deep Pelvic Abscesses Using a Combined Transrectal Sonographic and Fluoroscopic Guidance

    Jeong, Kyung Soon; Lee, Eun Jung; Ko, Ji Ho; Joh, Young Duk [Gospel Hospital, Kosin University College of Medicine, Busan (Korea, Republic of); Jung, Gyoo Sik [Ulsan Hospital, Ulsan (Korea, Republic of)


    To evaluate the feasibility and clinical efficacy of transrectal drainage of a deep pelvic abscess using combined transrectal sonographic and fluoroscopic guidance. From March 1995 and August 2004, 17 patients (9 men; 8 women; mean age, 39 years) suffering from pelvic pain, fever and leukocytosis were enrolled in this retrospective study. Ultrasound (US) or computed tomography (CT), which was obtained prior to the procedure, showed pelvic fluid collections that were deemed unapproachable by the percutaneous trans abdominal routes. Transrectal drainage of the pelvic abscess was performed under combined transrectal sonographic and fluoroscopic guidance. The causes of the deep pelvic abscess were postoperative complications (n=7), complications associated with radiation (n=3) and chemotherapy (n=1) as well as unknown causes (n=6). A 7.5-MHz end-firing transrectal US probe with a needle biopsy guide attachment was advanced into the rectum. Once the abscess was identified, a needle was advanced via the biopsy guide and the abscess was punctured. Under US guidance, either a 0.018'or 0.035' guide wire was passed through the needle in the abscess. Under fluoroscopic guidance, the tract was dilated to the appropriate diameter with sequential fascial dilators, and a catheter was placed over the guide wire within the abscess. Clinical success of drainage was determined by a combination closure of the cavity on the follow up images and diminished leukocytosis. The technical and clinical success rate, complications, and patient's discomfort were analyzed. Drainage was technically successful in all patients and there were no serious complications. Surgery was eventually performed in two cases due to fistular formation with the rectum and leakage of the anastomosis site. The procedure was well tolerated in all but one patient who complained of discomfort while the catheter was inserted . The catheter did not interfere with defecation and there was no incidence of

  9. Fluoroscopically-guided micropuncture femoral artery access for large-caliber sheath insertion.

    Cilingiroglu, Mehmet; Feldman, Ted; Salinger, Michael H; Levisay, Justin; Turi, Zoltan G


    Over the last decade, significant developments have been made in the treatment of structural heart disease. Some of these techniques require placement of large arterial sheaths for device delivery. Optimal vascular access is essential for successful large-vessel sheath insertion as well as to avoid vascular complications. The critical step for ideal percutaneous vessel entry is single anterior wall-only puncture of the common femoral artery in a location above the femoral bifurcation and below the inguinal ligament. We describe a fluoroscopically-guided micropuncture technique for accurate placement of large-caliber arterial sheaths.

  10. Short-term outcome of fluoroscopic-guided steroid injection therapy of lumber facet cyst-induced radicular pain

    Kwon, Mi Ri; Kwon, Jong Won; Lee, Jong Seo; Kim, Eu Sang [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)


    To determine the short-term effect of fluoroscopic-guided steroid injection therapy of lumbar facet cyst-induced radicular pain. Seventeen patients with radiculopathy due to lumbar synovial cysts, who were treated with fluoroscopically guided injection, were retrospectively evaluated. All plain radiographic images and MR images before the therapy were reviewed. Five patients underwent only the facet joint injection, whereas twelve patients underwent the facet joint injection with perineural injection therapy. The clinical course of pain was evaluated on the first follow-up after therapy. Effective pain relief was achieved in 11 (64.7%) of the 17 patients. Among 12 patients who underwent facet joint injection with perineural injection, 9 patients (75%) had an effective pain relief. Of 5 patients, 2 (40%) patients only took the facet joint injection and had an effective pain relief. Fluoroscopic-guided steroid injection therapy shows a good short-term effect in patients with symptomatic lumbar facet joint synovial cysts.

  11. T-Fastener Gastropexy and Percutaneous Gastrostomy Under CT-Fluoroscopic Guidance in a Patient with Partial Gastrectomy

    Siu-Cheung Chan


    Full Text Available The real-time images of computed tomography (CT-fluoroscopy provide an excellent means of guidance for percutaneous interventions. We describe the performance of T-fastener gastropexy and percutaneous gastrostomy under CT-fluoroscopic guidance in a 59-year-old woman who had received total pharyngolaryngectomy for hypopharyngeal cancer and partial gastrectomy with Billroth II anastomosis for bleeding gastric ulcer 10 years before this operation. The previous gastric operation altered the gastrointestinal anatomy and made conventional fluoroscopic-guided percutaneous gastrostomy extremely difficult and risky. The T-fastener gastropexy and percutaneous gastrostomy were accomplished smoothly in a single session using CT-fluoroscopic guidance. This modified method of percutaneous gastrostomy may be useful in patients with anatomic distortion due to previous gastric surgery.

  12. Fluoroscopic bone fragment tracking for surgical navigation in femur fracture reduction by incorporating optical tracking of hip joint rotation center.

    Nakajima, Yoshikazu; Tashiro, Takahito; Sugano, Nobuhiko; Yonenobu, Kazuo; Koyama, Tsuyoshi; Maeda, Yuki; Tamura, Yuichi; Saito, Masanobu; Tamura, Shin'ichi; Mitsuishi, Mamoru; Sugita, Naohiko; Sakuma, Ichiro; Ochi, Takahiro; Matsumoto, Yoichiro


    A new method for fluoroscopic tracking of a proximal bone fragment in femoral fracture reduction is presented. The proposed method combines 2-D and 3-D image registration from single-view fluoroscopy with tracking of the head center position of the proximal femoral fragment to improve the accuracy of fluoroscopic registration without the need for repeated manual adjustment of the C-arm as required in stereo-view registrations. Kinematic knowledge of the hip joint, which has a positional correspondence with the femoral head center and the pelvis acetabular center, allows the position of the femoral fragment to be determined from pelvis tracking. The stability of the proposed method with respect to fluoroscopic image noise and the desired continuity of the fracture reduction operation is demonstrated, and the accuracy of tracking is shown to be superior to that achievable by single-view image registration, particularly in depth translation.

  13. Percutaneous radiofrequency ablation for lung tumors beneath the rib under CT fluoroscopic guidance with gantry tilt

    Suzuki, Takanobu; Yamagami, Takuji; Tanaka, Osamu; Yoshimatsu, Rika; Miura, Hiroshi; Nishimura, Tsunehiko (Dept. of Radiology, Graduate School of Medical Science, Kyoto Prefectural Univ. of Medicine, Kamigyo, Kyoto (Japan)), e-mail:


    Background: Radiofrequency (RF) ablation of lung tumors has become a treatment of choice, especially for unresectable cases. However, RF ablation of small lung lesions located just beneath the rib is difficult. Purpose: To evaluate the efficacy and safety of gantry tilting for the performance of RF ablation of peripheral lesions located beneath the rib. Material and Methods: Our study was based on 18 of 293 lesions in the lung for which RF ablation was performed under CT scan fluoroscopic guidance at our institution between October 2004 and March 2009. For these 18 lesions, RF ablation was performed with gantry tilting because a rib blocked visualization of the RF ablation route even after other attempts had been made to change the relationship between the target and the rib. Results: All RF needles, with only one exception, were successfully advanced to hit the tumor. The commonest complication was a pneumothorax, which occurred in seven procedures. No serious complications occurred. The progression-free rates were 82.4% at 6 months, 62.5% at 12 months, and 30% at 24 months. Mean local progression-free duration was 17.6+-11.6 months (range 4-36 months). Conclusion: RF ablation under CT scan fluoroscopic guidance with gantry tilt is a useful and safe technique for RF ablation of lung nodules located beneath the rib

  14. A C-arm calibration method with application to fluoroscopic image-guided procedures

    Rai, Lav; Gibbs, Jason D.; Wibowo, Henky


    C-arm fluoroscopy units provide continuously updating X-ray video images during surgical procedure. The modality is widely adopted for its low cost, real-time imaging capabilities, and its ability to display radio-opaque tools in the anatomy. It is, however, important to correct for fluoroscopic image distortion and estimate camera parameters, such as focal length and camera center, for registration with 3D CT scans in fluoroscopic imageguided procedures. This paper describes a method for C-arm calibration and evaluates its accuracy in multiple C-arm units and in different viewing orientations. The proposed calibration method employs a commerciallyavailable unit to track the C-arm and a calibration plate. The method estimates both the internal calibration parameters and the transformation between the coordinate systems of tracker and C-arm. The method was successfully tested on two C-arm units (GE OEC 9800 and GE OEC 9800 Plus) of different image intensifier sizes and verified with a rigid airway phantom model. The mean distortion-model error was found to be 0.14 mm and 0.17 mm for the respective C-arms. The mean overall system reprojection error (which measures the accuracy of predicting an image using tracker coordinates) was found to be 0.63 mm for the GE OEC 9800.

  15. Discrepancy between fluoroscopic arthrography and magnetic resonance arthrography in patients with arthroscopically confirmed supraspinatus tendon tears: The additional benefit of cine fluoroscopic arthrography images

    Hahn, Seok; Lee, Young Han; Suh, Jin Suck [Dept. Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of)


    To determine the additional diagnostic benefits of fluoroscopic arthrography (FA) in patients with full-thickness supraspinatus tendon (SST) tears by comparing FA images with magnetic resonance arthrography (MRA) images. This study included FA and MRA images of 53 patients who were confirmed to have full-thickness SST tears by arthroscopy. In the FA analysis, the presence of contrast leakage into the subacromial-subdeltoid bursa was recorded. In the MRA analysis, contrast leakage, retraction of a torn tendon, width and length of the tear, and supraspinatus atrophy were evaluated. Patients were divided into the concordant group or the discordant group based on the presence of contrast leakage to compare the characteristics of SST tears. We used Fisher's exact test and two-sample t-test for the comparison. Of the 53 patients, 34 were included in the concordant group and 19 were included in the discordant group. In the concordant group, the grades of retraction were higher than those in the discordant group; the width and length of the tears were larger. Muscle atrophy was more severe in the concordant group. A full-thickness SST tear did not always exhibit contrast leakage on FA, particularly small SST tears or tears with low-grade retraction. FA can provide diagnostic information regarding the severity of full-thickness SST tears by itself.

  16. Image-guided transapical aortic valve implantation: sensorless tracking of stenotic valve landmarks in live fluoroscopic images.

    Merk, Denis R; Karar, Mohamed Esmail; Chalopin, Claire; Holzhey, David; Falk, Volkmar; Mohr, Friedrich W; Burgert, Oliver


    Aortic valve stenosis is one of the most frequently acquired valvular heart diseases, accounting for almost 70% of valvular cardiac surgery. Transapical transcatheter aortic valve implantation has recently become a suitable minimally invasive technique for high-risk and elderly patients with severe aortic stenosis. In this article, we aim to automatically define a target area of valve implantation, namely, the area between the coronary ostia and the lowest points of two aortic valve cusps. Therefore, we present a new image-based tracking method of these aortic landmarks to assist in the placement of aortic valve prosthesis under live 2D fluoroscopy guidance. We propose a rigid intensity-based image registration technique for tracking valve landmarks in 2D fluoroscopic image sequences, based on a real-time alignment of a contrast image including the initialized manual valve landmarks to each image of sequence. The contrast image is automatically detected to visualize aortic valve features when the aortic root is filled with a contrast agent. Our registration-based tracking method has been retrospectively applied to 10 fluoroscopic image sequences from routine transapical aortic valve implantation procedures. Most of all tested fluoroscopic images showed a successful tracking of valve landmarks, especially for the images without contrast agent injections. A new intraoperative image-based method has been developed for tracking aortic valve landmarks in live 2D fluoroscopic images to assist transapical aortic valve implantations and to increase the overall safety of surgery as well.

  17. Fluoroscopic-guided covered metallic stent placement for gastric outlet obstruction and post-operative gastroenterostomy anastomotic stricture

    Lee, Jeong Min; Han, Young Min; Kim, Chong Soo; Lee, Sang Young; Lee, Soo Teik; Yang, Doo Hyun


    AIM: To evaluate the feasibility and safety of fluoroscopic-guided covered metallic stent placements in providing palliative care for patients with inoperable malignant gastric outlet obstruction. MATERIALS AND METHODS: Under fluoroscopic guidance, placement of self-expandable, covered stents was attempted in 20 patients with inoperable or recurrent gastric cancer (age range 36-79 years). All patients had inoperable gastric outlet obstruction, 13 with native anatomy and seven with post-operative anatomy (gastrointestinal anastomotic sites). All patients had intolerance to oral alimentation and/or vomiting after ingestion. Success was defined both technically and clinically. RESULTS: The placement of the stent was technically successful in 18 patients and failed in two patients (technical success: 90%). The cause of the technical failures was an inability to negotiate the guide wire through the obstruction sites in spite of the use of both fluoroscopic and endoscopic guidance. After stent placement, 15 patients were able to ingest at least liquids and had a markedly decreased incidence of vomiting (clinical success: 75%). During the mean follow-up of 6 weeks, there have been no stent reocclusion and no life-threatening complications except migration of two stents in one patient. CONCLUSION: Fluoroscopically guided covered metallic stent placement appears to be valuable for the palliative treatment of malignant obstruction of gastric outlet and post-operative gastrointestinal anastomoses. Lee, J.M. et al. (2001)

  18. A prospective evaluation of complications of 10,000 fluoroscopically directed epidural injections.

    Manchikanti, Laxmaiah; Malla, Yogesh; Wargo, Bradley W; Cash, Kimberly A; Pampati, Vidyasagar; Fellows, Bert


    Among the multiple modalities of treatments available in managing chronic spinal pain, including surgery and multiple interventional techniques, epidural injections by various routes, such as interlaminar epidural injections, caudal epidural injections, transforaminal epidural injections, and percutaneous adhesiolysis are common. Even though the complications of fluoroscopically directed epidural injections are fewer than blind epidural injections, and have better effectiveness, multiple complications have been reported in scattered case reports, with only minor complications in randomized or non-randomized studies and systematic reviews. Thus, prospective studies with large patient series are essential to determine the types and incidences of complications. A prospective, non-randomized study of patients undergoing interventional techniques from May 2008 to December 2009. A private interventional pain management practice, a specialty referral center in the United States. To assess the complication rate of fluoroscopically directed epidural injections. This study was carried out over a period of 20 months and included over 10,000 procedures: 39% caudal epidurals, 23% cervical interlaminar epidurals, 14% lumbar interlaminar epidurals, 13% lumbar transforaminal epidurals, 8% percutaneous adhesiolysis, and 3% thoracic interlaminar epidural procedures. All of the interventions were performed under fluoroscopic guidance in an ambulatory surgery center by one of 3 physicians. The complications encountered during the procedure and postoperatively were prospectively evaluated. Measurable outcomes employed were intravascular entry of the needle, profuse bleeding, local hematoma, bruising, dural puncture and headache, nerve root or spinal cord irritation with resultant injury, infectious complications, vasovagal reactions, and facial flushing. Intravascular entry was higher for adhesiolysis (11.6%) and lumbar transforaminal (7.9%) procedures compared to other epidurals which

  19. Fluoroscopically Guided Three-Tube Insertion for the Treatment of Postoperative Gastroesophageal Anastomotic Leakage

    Yin, Guowen; Xu, Qingyu; Chen, Shixi; Bai, Xiangjun; Jiang, Feng; Zhang, Qin; Xu, Lin; Xu, Weidong [Cancer Hospital of Jiangsu Province, Nanjing (Korea, Republic of)


    To retrospectively evaluate the feasibility and effectiveness of three-tube insertion for the treatment of postoperative gastroesophageal anastomotic leakage (GEAL). From January 2007 to January 2011, 28 cases of postoperative GEAL after an esophagectomy with intrathoracic esophagogastric anastomotic procedures for esophageal and cardiac carcinoma were treated by the insertion of three tubes under fluoroscopic guidance. The three tubes consisted of a drainage tube through the leak, a nasogastric decompression tube, and a nasojejunum feeding tube. The study population consisted of 28 patients (18 males, 10 females) ranging in their ages from 36 to 72 years (mean: 59 years). We evaluated the feasibility of three-tube insertion to facilitate leakage site closure, and the patients' nutritional benefit by checking their serum albumin levels between pre- and post-enteral feeding via the feeding tube. The three tubes were successfully placed under fluoroscopic guidance in all twenty-eight patients (100%). The procedure times for the three tube insertion ranged from 30 to 70 minutes (mean time: 45 minutes). In 27 of 28 patients (96%), leakage site closure after three-tube insertion was achieved, while it was not attained in one patient who received stent implantation as a substitute. All patients showed good tolerance of the three-tube insertion in the nasal cavity. The mean time needed for leakage treatment was 21 {+-} 3.5 days. The serum albumin level change was significant, increasing from pre-enteral feeding (2.5 {+-} 0.40 g/dL) to post-enteral feeding (3.7 {+-} 0.51 g/dL) via the feeding tube (p < 0.001). The duration of follow-up ranged from 7 to 60 months (mean: 28 months). Based on the results of this study, the insertion of three tubes under fluoroscopic guidance is safe, and also provides effective relief from postesophagectomy GEAL. Moreover, our findings suggest that three-tube insertion may be used as the primary procedure to treat postoperative GEAL.

  20. MO-F-CAMPUS-I-02: Occupational Conceptus Doses From Fluoroscopically-Guided Interventional Procedures

    Damilakis, J; Perisinakis, K; Solomou, G [University of Crete (Greece); Stratakis, J [University of Crete, Heraklion, Crete (Greece)


    Purpose: The aim of this method was to provide dosimetric data on conceptus dose for the pregnant employee who participates in fluoroscopically-guided interventional procedures. Methods: Scattered air-kerma dose rates were obtained for 17 fluoroscopic projections involved in interventional procedures. These projections were simulated on an anthropomorphic phantom placed on the examination table supine. The operating theater was divided into two grids relative to the long table sides. Each grid consisted of 33 cells spaced 0.50 m apart. During the simulated exposures, at each cell, scatter air-kerma rate was measured at 110 cm from the floor i.e. at the height of the waist of the pregnant worker. Air-kerma rates were divided by the dose area product (DAP) rate of each exposure to obtain normalized data. For each projection, measurements were performed for 3 kVp and 3 filtration values i.e. for 9 different x-ray spectra. All measurements were performed by using a modern C-arm angiographic system (Siemens Axiom Artis, Siemens, Germany) and a radiation meter equipped with an ionization chamber. Results: The results consist of 153 iso-dose maps, which show the spatial distribution of DAP-normalized scattered air-kerma doses at the waist level of a pregnant worker. Conceptus dose estimation is possible using air-kerma to embryo/fetal dose conversion coefficients published in a previous study (J Cardiovasc Electrophysiol, Vol. 16, pp. 1–8, July 2005). Using these maps, occupationally exposed pregnant personnel may select a working position for a certain projection that keeps abdominal dose as low as reasonably achievable. Taking into consideration the regulatory conceptus dose limit for occupational exposure, determination of the maximum workload allowed for the pregnant personnel is also possible. Conclusion: Data produced in this work allow for the anticipation of conceptus dose and the determination of the maximum workload for a pregnant worker from any

  1. Radiation Dose Reduction Methods For Use With Fluoroscopic Imaging, Computers And Implications For Image Quality

    Edmonds, E. W.; Hynes, D. M.; Rowlands, J. A.; Toth, B. D.; Porter, A. J.


    The use of a beam splitting device for medical gastro-intestinal fluoroscopy has demonstrated that clinical images obtained with a 100mm photofluorographic camera, and a 1024 X 1024 digital matrix with pulsed progressive readout acquisition techniques, are identical. In addition, it has been found that clinical images can be obtained with digital systems at dose levels lower than those possible with film. The use of pulsed fluoroscopy with intermittent storage of the fluoroscopic image has also been demonstrated to reduce the fluoroscopy part of the examination to very low dose levels, particularly when low repetition rates of about 2 frames per second (fps) are used. The use of digital methods reduces the amount of radiation required and also the heat generated by the x-ray tube. Images can therefore be produced using a very small focal spot on the x-ray tube, which can produce further improvement in the resolution of the clinical images.

  2. Use of a fluoroscopic overlay to guide femoral tunnel placement during posterior cruciate ligament reconstruction.

    Araujo, Paulo H; Moloney, Gele; Rincon, Gustavo; Carey, Robert; Zhang, Xudong; Harner, Christopher


    Intraoperative recognition of the local anatomy of the posterior cruciate ligament (PCL) is difficult for many surgeons, and correct positioning of the graft can be challenging. To investigate the efficacy of an overlay system based on fluoroscopic landmarks in guiding femoral tunnel placement during PCL reconstruction. Controlled laboratory study. Twenty cadaveric knees were arthroscopically prepared, and their PCL femoral insertion sites were digitized. The digitized images were co-registered to computed tomography-acquired 3-dimensional bone models. Twenty surgeons with diverse backgrounds performed simulated arthroscopic reconstruction of the anterolateral (AL) and posteromedial (PM) bundles of the PCL, first without and then with the aid of a lateral fluoroscopic image on which the position of a target insertion site based on literature data was displayed as an overlay. The surgeons were allowed to adjust tunnel placement in accordance with the displayed target position. A 3-way comparison was made of the tunnel positions placed by the surgeons, the native insertion site positions, and the literature-based positions. The overlay system was effective in helping surgeons to improve femoral tunnel placement toward the target and toward the anatomic insertion site (P 5 mm from the native insertion site. With the use of the overlay, 70% of the surgeons were overlay to guide intraoperative placement of the femoral tunnel(s) during PCL reconstruction can result in more anatomic reconstructions and therefore assist in re-creating native knee kinematics after PCL reconstruction. Intraoperative fluoroscopy is an effective, easy, and safe method for improving femoral tunnel positioning during PCL reconstruction. © 2014 The Author(s).

  3. Accurate 3D kinematic measurement of temporomandibular joint using X-ray fluoroscopic images

    Yamazaki, Takaharu; Matsumoto, Akiko; Sugamoto, Kazuomi; Matsumoto, Ken; Kakimoto, Naoya; Yura, Yoshiaki


    Accurate measurement and analysis of 3D kinematics of temporomandibular joint (TMJ) is very important for assisting clinical diagnosis and treatment of prosthodontics and orthodontics, and oral surgery. This study presents a new 3D kinematic measurement technique of the TMJ using X-ray fluoroscopic images, which can easily obtain the TMJ kinematic data in natural motion. In vivo kinematics of the TMJ (maxilla and mandibular bone) is determined using a feature-based 2D/3D registration, which uses beads silhouette on fluoroscopic images and 3D surface bone models with beads. The 3D surface models of maxilla and mandibular bone with beads were created from CT scans data of the subject using the mouthpiece with the seven strategically placed beads. In order to validate the accuracy of pose estimation for the maxilla and mandibular bone, computer simulation test was performed using five patterns of synthetic tantalum beads silhouette images. In the clinical applications, dynamic movement during jaw opening and closing was conducted, and the relative pose of the mandibular bone with respect to the maxilla bone was determined. The results of computer simulation test showed that the root mean square errors were sufficiently smaller than 1.0 mm and 1.0 degree. In the results of clinical application, during jaw opening from 0.0 to 36.8 degree of rotation, mandibular condyle exhibited 19.8 mm of anterior sliding relative to maxillary articular fossa, and these measurement values were clinically similar to the previous reports. Consequently, present technique was thought to be suitable for the 3D TMJ kinematic analysis.

  4. Non-fluoroscopic navigation systems for radiofrequency catheter ablation for supraventricular tachycardia reduce ionising radiation exposure.

    See, Jason; Amora, Jonah L; Lee, Sheldon; Lim, Paul; Teo, Wee Siong; Tan, Boon Yew; Ho, Kah Leng; Lee, Chee Wan; Ching, Chi-Keong


    The use of non-fluoroscopic systems (NFS) to guide radiofrequency catheter ablation (RFCA) for the treatment of supraventricular tachycardia (SVT) is associated with lower radiation exposure. This study aimed to determine if NFS reduces fluoroscopy time, radiation dose and procedure time. We prospectively enrolled patients undergoing RFCA for SVT. NFS included EnSiteTM NavXTM or CARTO® mapping. We compared procedure and fluoroscopy times, and radiation exposure between NFS and conventional fluoroscopy (CF) cohorts. Procedural success, complications and one-year success rates were reported. A total of 200 patients over 27 months were included and RFCA was guided by NFS for 79 patients; those with atrioventricular nodal reentrant tachycardia (AVNRT), left-sided atrioventricular reentrant tachycardia (AVRT) and right-sided AVRT were included (n = 101, 63 and 36, respectively). Fluoroscopy times were significantly lower with NFS than with CF (10.8 ± 11.1 minutes vs. 32.0 ± 27.5 minutes; p < 0.001). The mean fluoroscopic dose area product was also significantly reduced with NFS (NSF: 5,382 ± 5,768 mGy*cm2 vs. CF: 21,070 ± 23,311 mGy*cm2; p < 0.001); for all SVT subtypes. There was no significant reduction in procedure time, except for left-sided AVRT ablation (NFS: 79.2 minutes vs. CF: 116.4 minutes; p = 0.001). Procedural success rates were comparable (NFS: 97.5% vs. CF: 98.3%) and at one-year follow-up, there was no significant difference in the recurrence rates (NFS: 5.2% vs. CF: 4.2%). No clinically significant complications were observed in both groups. The use of NFS for RFCA for SVT is safe, with significantly reduced radiation dose and fluoroscopy time. Copyright © Singapore Medical Association.

  5. Efficient segmentation of 3D fluoroscopic datasets from mobile C-arm

    Styner, Martin A.; Talib, Haydar; Singh, Digvijay; Nolte, Lutz-Peter


    The emerging mobile fluoroscopic 3D technology linked with a navigation system combines the advantages of CT-based and C-arm-based navigation. The intra-operative, automatic segmentation of 3D fluoroscopy datasets enables the combined visualization of surgical instruments and anatomical structures for enhanced planning, surgical eye-navigation and landmark digitization. We performed a thorough evaluation of several segmentation algorithms using a large set of data from different anatomical regions and man-made phantom objects. The analyzed segmentation methods include automatic thresholding, morphological operations, an adapted region growing method and an implicit 3D geodesic snake method. In regard to computational efficiency, all methods performed within acceptable limits on a standard Desktop PC (30sec-5min). In general, the best results were obtained with datasets from long bones, followed by extremities. The segmentations of spine, pelvis and shoulder datasets were generally of poorer quality. As expected, the threshold-based methods produced the worst results. The combined thresholding and morphological operations methods were considered appropriate for a smaller set of clean images. The region growing method performed generally much better in regard to computational efficiency and segmentation correctness, especially for datasets of joints, and lumbar and cervical spine regions. The less efficient implicit snake method was able to additionally remove wrongly segmented skin tissue regions. This study presents a step towards efficient intra-operative segmentation of 3D fluoroscopy datasets, but there is room for improvement. Next, we plan to study model-based approaches for datasets from the knee and hip joint region, which would be thenceforth applied to all anatomical regions in our continuing development of an ideal segmentation procedure for 3D fluoroscopic images.

  6. Magnetic Resonance Enterography Findings in Crohn′s disease in the Pediatric Population and Correlation with Fluoroscopic and Multidetector Computed Tomographic Techniques

    Parul Patel; Margaret Ormanoski; Hoadley, Kim M.


    Traditionally, fluoroscopic examinations such as enteroclysis, upper GI studies, and small bowel follow through exams have been the procedures of choice in evaluating inflammatory bowel disease (IBD) in pediatric populations. With the advent of multidetector computed tomography (MDCT), it has subsequently become a complementary examination in imaging inflammatory bowel disease. A major advantage of MDCT over fluoroscopic examination is its ability to directly visualize bowel mucosa, as well a...

  7. Robust fluoroscopic respiratory gating for lung cancer radiotherapy without implanted fiducial markers

    Cui, Ying; Dy, Jennifer G.; Sharp, Greg C.; Alexander, Brian; Jiang, Steve B.


    For gated lung cancer radiotherapy, it is difficult to generate accurate gating signals due to the large uncertainties when using external surrogates and the risk of pneumothorax when using implanted fiducial markers. We have previously investigated and demonstrated the feasibility of generating gating signals using the correlation scores between the reference template image and the fluoroscopic images acquired during the treatment. In this paper, we present an in-depth study, aiming at the improvement of robustness of the algorithm and its validation using multiple sets of patient data. Three different template generating and matching methods have been developed and evaluated: (1) single template method, (2) multiple template method, and (3) template clustering method. Using the fluoroscopic data acquired during patient setup before each fraction of treatment, reference templates are built that represent the tumour position and shape in the gating window, which is assumed to be at the end-of-exhale phase. For the single template method, all the setup images within the gating window are averaged to generate a composite template. For the multiple template method, each setup image in the gating window is considered as a reference template and used to generate an ensemble of correlation scores. All the scores are then combined to generate the gating signal. For the template clustering method, clustering (grouping of similar objects together) is performed to reduce the large number of reference templates into a few representative ones. Each of these methods has been evaluated against the reference gating signal as manually determined by a radiation oncologist. Five patient datasets were used for evaluation. In each case, gated treatments were simulated at both 35% and 50% duty cycles. False positive, negative and total error rates were computed. Experiments show that the single template method is sensitive to noise; the multiple template and clustering methods are more

  8. The need for using fluoroscopic guidance to obtain gastric biopsies when in search of Helicobacter pylori with a nonendoscopic method

    Bender, Greg N.; Mullins, Daniel J.; Makuch, Richard S


    Purpose: Nonendoscopic, fluoroscopic biopsy of the gastric mucosa, following barium examination of the stomach, has gained attention with its ease of performance and cost savings potential over endoscopy. Endoscopic research concerning the efficacy of biopsy sites has revealed an increased sensitivity of antral biopsies over greater curvature biopsies for the detection of Helicobacter pylori. Fluoroscopically guided biopsies of the gastric mucosal are studied to determine whether such a difference between site sensitivity held true. If not, blind biopsy through a nasogastric tube, which traditionally samples only the greater curvature, might prove an even less expensive alternative. Materials and methods: Seventy-two patients underwent nonendoscopic, fluoroscopically guided, mucosal biopsy of both the gastric antrum and the greater curvature of the stomach. Pathologic reports from both sites, using each patient as their own control, are compared to assess site sensitivity in the diagnosis of H. pylori gastritis. Results: The sensitivity for the detection of H. pylori gastritis by antral biopsy is 89% whereas the sensitivity of greater curvature biopsy is 62%. The difference is considered clinically significant at P{<=}0.05. Conclusions: This study confirms the need for antral biopsies when desiring a nonendoscopic approach to gastric mucosal sampling, in order to obtain a reasonable yield of data in dyspeptic patients with H. pylori gastritis. Blind techniques cannot reliably reach the antrum. Fluoroscopy can, and remains a less expensive alternative to endoscopy.

  9. Effectiveness of Fluoroscopic and US - Guided Percutaneous Catheter Drainage for Iliopsoas Abscess through the Anterolateral Transabdominal Approach

    Choi, Ho Cheol; Shin, Tae Beom; Park, Mee Jung; Kim, Ji Eun; Choi, Hye Young; Bae, Kyung Soo; Choi, Dae Seob; Na, Jae Boem; Jeong, Seong Hoon [Gyeongsang National University Hospital, College of Medicine, Jinju (Korea, Republic of)


    We evaluated the effectiveness of performing fluoroscopic and ultrasonography guided percutaneous catheter drainage (PCD) through the anterolateral transabdominal approach for treating iliopsoas abscess. From January 2008 to December 2009, fluoroscopic and US-guided PCD through the anterolateral transabdominal approach was performed on sixteen iliopsoas abscesses of fourteen patients (7 males and 7 females; mean age: 63 years; age range: 30-87 years). Six abscesses were on the right side and ten abscesses were on the left side. The location of the abscesses were the psoas muscle (n=7), the iliacus muscle (n=7) and the iliopsoas muscle (n=2). All the procedures were performed under fluoroscopy and US guidance in the angiography room. The clinical findings before and after the procedure, the duration of catheter insertion and the procedure-related complications were evaluated. 15 out of the 16 iliopsoas abscesses were effectively treated. The duration of catheter insertion was 5- 27 days (mean: 14.6) days. No patient had significant complications during or after drainage. One patient died of uncontrolled diabetes complications and shock on the 9th day after percutaneous catheter drainage. One recurrence was noted 5 months after removal of the catheter. This patient underwent aspiration and antibiotic treatment for this lesion and the patient improved. Fluoroscopic and US-guided PCD for iliopsoas abscess through the anterolateral transabdominal approach is an effective and safe procedure

  10. Percutaneous vertebroplasty: optimizing the procedure after treatment of 250 vertebral levels under fluoroscopic guidance.

    Pedicelli, A; Rollo, M; Piano, M; Grattacaso, G; Colosimo, C; Bonomo, L


    Percutaneous vertebroplasty (PVP) is a minimally invasive treatment for symptomatic vertebral compression fractures (VCFs). The aim of this study was to assess the effectiveness, complications and progress of results of PVP optimized in terms of technique, costs, time and strategic protocol after 3 years of procedures performed under fluoroscopic guidance alone. We treated 250 VCFs in 120 consecutive patients after assessing clinical and radiological indications. The effectiveness of the procedure was determined by statistical analysis of numerical scores for pain, mobility and drug consumption before and after treatment. No major complications and only three minor complications occurred. Clinically relevant improved mobility and reduction of pain and analgesics were observed, with overall significant results (p<0.0001) in all patients at 24 h after PVP and in 83 available patients at 6 months. A total of five asymptomatic refractures of cemented vertebrae and 14 new symptomatic vertebral fractures at different levels were observed between 1 and 10 months after the procedure. PVP is a safe, rapid, effective and costeffective therapy for VCFs, requiring only brief hospital admission and with long-lasting clinical results, when performed under good-quality radiological guidance, when correct indications are respected and when it is associated with rehabilitation therapy in the follow-up. It is a valid alternative to conservative therapy, which is burdened by high healthcare costs and often requires long-term immobilisation of frail and elderly patients at risk of clinical complications.

  11. [Percutaneous fluoroscopic and arthroscopic controlled screw fixation of posterior facet fractures of the calcaneus].

    Nehme, A; Chaminade, B; Chiron, P; Fabie, F; Tricoire, J-L; Puget, J


    We describe a new technique for reduction and percutaneous osteosynthesis of displaced posterior facet fractures of the calcaneus which appears to overcome the problems encountered with other percutaneous methods described for this type of surgery. The method relies on the use of traction which allows automatic reduction of the greater tubersosity. The patient is installed on an orthopedic traction table. Pin traction provides anatomic reduction of the posterior articular surface and restitution of Böhler's angle under fluoroscopic and arthroscopic control. We used this technique in thirteen patients with fifteen displaced posterior facet fractures of the calcaneum. Mean patient age was 50.4 Years. Mean follow-up was twenty Months. We did not have any cutaneous or infectious complications in this short series. In the majority of the cases, the overall functional and physical results were excellent or good. The mean Böhler's angle was 27 degrees, corresponding to 83% correction compared with the healthy side. These preliminary results are encouraging. We were able to restitute calcaneum anatomy, shorten hospital stay, and avoid all skin complications. Indications for this percutaneous technique could be widened. It is a valid alternative to open treatment of posterior facet fractures of the calcaneum.

  12. Basal cell carcinoma and breast carcinoma following repeated fluoroscopic examinations of the chest.

    Myskowski, P L; Gumpertz, E; Safai, B


    A 69-year-old white Italian woman was first seen at Memorial Sloan-Kettering Cancer Center in 1981 concerning several skin growths on her back. The patient had had several basal cell carcinomas surgically removed from her back during the preceding 5 years. There was no history of arsenic ingestion or prolonged sun exposure and her family history was negative for skin cancer. The patient had developed pulmonary tuberculosis in 1938 and was treated with pneumothorax therapy. She had had more than 50 fluoroscopic examinations of the chest following this therapy, as well as multiple diagnostic x-ray films since that time. She recalled that she had faced the fluoroscopy beam during the procedure. In 1959, she had a transabdominal hysterectomy for fibroid tumors. In 1980 she underwent a right modified radical mastectomy for adenoid cystic carcinoma of the breast; biopsies of lymph nodes were negative. Physical examination revealed a thin, white woman with a right mastectomy scar. On the back, clustered in the interscapular region, were multiple scars and nine erythematous nodules with pearly borders, telangiectasia, and translucent surfaces. Within several nodules there were areas of light and dark brown pigmentation. There were no other suspicious lesions on the head, chest, or extremities, nor did the patient show any evidence of the basal cell nevus syndrome. Biopsy of all lesions revealed basal cell carcinoma, some of which were pigmented, without evidence of chronic radiodermatitis. All lesions were treated with curettage and electrodesiccation three times with good cosmetic results (Fig. 1).

  13. Placement of central venous access via subclavian vein under fluoroscopic guidance with intravenous contrast injection

    Choo, Sung Wook; Choo, In Wook; Do, Young Soo; Kim, Seung Hoon; Yoh, Kyu Tong; Ro, Duk Woo; Kim, Bo Kyung [Samsung Medical Center, Seoul (Korea, Republic of)


    To evaluate the safety and efficacy of Hickman catheter placement via the subclavian vein under fluoroscopic guidance with intravenous contrast injection. During an eleven-month period, 187 Hickman catheters were percutaneously placed in 167 consecutive patients in an interventional radiology suite. Subclavian venous puncture was made with injection of contrast medium into the peripheral venous line. After subclavian venous access had been obtained, a subcutaneous tunnel was created using a peel-away sheath or a tunneler. The Hickman catheters were inserted through a peel-away sheath, the distal tip of which was as the junction of the right atrium and the superior vena cava. One hundred and eighty-six Hickman catheters were successfully placed ; the one failure was due to anatomical tortuosity of the vein (0.53%). Complications included one case of subclavian vein occlusion (0.53%) ; three of line occlusion by thrombus (1.6%) ; one of oozing at the suture site (0.53%) ; six of infection or inflammation (3.2%) ; eight of natural removal (4.2%) ; one case of air embolism (0.53%) and two of malposition (0.1%). Major complications such as pneumothorax or arterial puncture leading to mediastinal hemorrhage did not, however, occur. The authors concluded that radiologic Hickman catheter placement offers advantages over traditional approaches in terms of safety, convenience, and time and cost savings.

  14. Treatment of degenerative chronic low back pain with fluoroscopically guided epidural procaine-corticosteroid injection

    Ćulafić Slobodan


    Full Text Available Background/Aim. Low back pain is one of the most common painful conditions in the modern age. Therefore, it is very important to establish the most effective protocol for the treatment of this condition. The aim of this study was to find out if fluoroscopically, guided epidural procainecorticosteroid injection is effective in the treatment of degenerative chronic low back pain. Methods. This prospective cohort study was performed in the Military Medical Academy from September 2005 to June 2006 and included 60 patients of both sexes, 34-85 years of age. Degenerative changes of lumbosacral spine were determined by magnetic resonance imaging. The intensity of low back pain was evaluated by subjective (Roland's scale and objective parameter (Lazarevic sign. Epidural procaine-corticosteroid injection was applied in the patients with low back pain not responding to conservative therapy. After the application of injection, effects of the therapy were followed up. Results. In 92% of the patients there was a reduction of pain intensity for three months, in 4.8% a reduction for a month, but after another injection they felt pain reduction for the next three months. One patient (2.3% had pain reduction for one month. Conclusion. In the treatment of degenerative chronic low back pain, not responding to conservative therapy with nonsteroidal anti-inflammatory drugs, epidural procaine-corticosteroid injection have a satisfactory short-term as well as a long-term analgesic effect.

  15. A novel fluoroscopic-assisted balloon thrombectomy technique for thrombosed hemodialysis prosthetic grafts [corrected].

    Kakkos, Stavros K; Haddad, Joseph A; Haddad, Georges K


    Previous studies have shown that stenosis of the arterial anastomosis of thrombosed hemodialysis (HD) grafts, unmasked after conventional thrombectomy, very often necessitate subsequent arterial angioplasty. The aim of this study was to describe a novel fluoroscopic-assisted balloon thrombectomy technique which permits simultaneous arterial angioplasty (should this is required) for thrombosed HD grafts. Thirty patients with 36 thrombotic episodes of their prosthetic HD grafts participated in this study. A balloon angioplasty catheter is placed beyond the arterial anastomosis, over a guidewire; the balloon is inflated with contrast solution under fluoroscopy and pulled back to remove the arterial thrombus from the anastomosis. Any coexisting stenosis revealed by balloon indentation is completely dilated at that time, rather than after the thrombectomy. Mechanical thrombolysis of the graft and venous outflow is then performed with the AngioJet catheter (Possis Medical, Inc). Technical and clinical success rates (the latter defined as one subsequent HD session) of the procedure were 100% and 94%, respectively. No complications, including arterial embolism, vessel rupture or pulmonary embolism, were encountered. Primary assisted patency at 3 and 6 months was 51% and 32%, respectively, while functional secondary patency at the same follow-up points was 78%. Our technique is safe and also effective in both short- and long-term follow-up. Because it offers convenience, since the treatment of arterial anastomotic stenoses is accomplished in one (rather than two) steps, this method deserves further investigation.

  16. Pediatric patient and staff dose measurements in barium meal fluoroscopic procedures

    Filipov, D.; Schelin, H. R.; Denyak, V.; Paschuk, S. A.; Porto, L. E.; Ledesma, J. A.; Nascimento, E. X.; Legnani, A.; Andrade, M. E. A.; Khoury, H. J.


    This study investigates patient and staff dose measurements in pediatric barium meal series fluoroscopic procedures. It aims to analyze radiographic techniques, measure the air kerma-area product (PKA), and estimate the staff's eye lens, thyroid and hands equivalent doses. The procedures of 41 patients were studied, and PKA values were calculated using LiF:Mg,Ti thermoluminescent dosimeters (TLDs) positioned at the center of the patient's upper chest. Furthermore, LiF:Mg,Cu,P TLDs were used to estimate the equivalent doses. The results showed a discrepancy in the radiographic techniques when compared to the European Commission recommendations. Half of the results of the analyzed literature presented lower PKA and dose reference level values than the present study. The staff's equivalent doses strongly depends on the distance from the beam. A 55-cm distance can be considered satisfactory. However, a distance decrease of ~20% leads to, at least, two times higher equivalent doses. For eye lenses this dose is significantly greater than the annual limit set by the International Commission on Radiological Protection. In addition, the occupational doses were found to be much higher than in the literature. Changing the used radiographic techniques to the ones recommended by the European Communities, it is expected to achieve lower PKA values ​​and occupational doses.

  17. X-ray characterization of CMOS imaging detector with high resolution for fluoroscopic imaging application

    Cha, Bo Kyung; Kim, Cho Rong; Jeon, Seongchae; Kim, Ryun Kyung; Seo, Chang-Woo; Yang, Keedong; Heo, Duchang; Lee, Tae-Bum; Shin, Min-Seok; Kim, Jong-Boo; Kwon, Oh-Kyung


    This paper introduces complementary metal-oxide semiconductor (CMOS) active pixel sensor (APS)-based X-ray imaging detectors with high spatial resolution for medical imaging application. In this study, our proposed X-ray CMOS imaging sensor has been fabricated by using a 0.35 μm 1 Poly 4 Metal CMOS process. The pixel size is 100 μm×100 μm and the pixel array format is 24×96 pixels, which provide a field-of-view (FOV) of 9.6 mm×2.4 mm. The 14.3-bit extend counting analog-to digital converter (ADC) with built-in binning mode was used to reduce the area and simultaneously improve the image resolution. Both thallium-doped CsI (CsI:Tl) and Gd2O2S:Tb scintillator screens were used as converters for incident X-rays to visible light photons. The optical property and X-ray imaging characterization such as X-ray to light response as a function of incident X-ray exposure dose, spatial resolution and X-ray images of objects were measured under different X-ray energy conditions. The measured results suggest that our developed CMOS-based X-ray imaging detector has the potential for fluoroscopic imaging and cone-beam computed tomography (CBCT) imaging applications.

  18. Transbronchial lung biopsy without fluoroscopic guide in Tehran Imam Khomeini’s Hospital (1999

    "Firoozbakhsh S


    Full Text Available Background: Transbronchial lung biopsy (TBLB is an attractive alternative to open lung biopsy as an initial diagnostic procedure for patients with diffuse parenchymal disease or localized densities beyond direct endoscopic vision. TBLB can be carried out safely without fluoroscopy in patients with diffuse lung disease. Since in our bronchoscopic department fluoroscopy is not available, we planned to evaluate the blind (without fluoroscopic guide TBLB being performed in our department to determine the success rate in obtaining lung tissue, the sensitivity of the procedure and the risk of complications. Materials and Methods: Sixty-Four TBLB were done in our department during a 6 month period (March-September 1999. Results: Lung tissue wasn’t detected in two (3.1 percent samples. Pathological results were helpful in 46 (71.9 percent cases. No evidence of hemoptysis was found after the procedure. Three (4.68 percent cases of pneumothorax was detected. Only one of them required chest tube (1.51 percent. Conclusion: We concluded that blind TBLB was successful in our department with rates of complications comparable to other approved centers.

  19. Fluoroscopically-Guided Posterior Approach for Shoulder Magnetic Resonance Arthrography: Comparison with Conventional Anterior Approach

    Yoo, Koun J.; Ha, Doo Hoe; Lee, Sang Min [Dept. of Radiology, CHA Budang Medical Center, CHA University College of Medicine, Seongnam (Korea, Republic of)


    To prospectively evaluate the usefulness of the fluoroscopically-guided posterior approach compared with the anterior approach for shoulder magnetic resonance(MR) arthrography. Institutional review board approval and informed consent were obtained. Among 60 shoulder MR arthrographies performed on 59 patients with symptomatic shoulders, an intra-articular injection was performed (30 cases using the anterior approach and 30 using the posterior approach). Procedure-related pain was assessed by using a 5 score visual analogue scale (VAS). Depth of the puncture and standardized depth of puncture by body mass index (BMI) were recorded. The contrast leakage along the course of the puncture was evaluated by reviewing the MR. The statistical analyses included the Mann-Whitney U and Kruskal-Wallis test. There was no significant difference in VAS scores between the anterior and posterior groups (1.77 {+-} 1.10 vs. 1.80 {+-} 0.96). Depth of puncture and standardized depth of puncture by BMI were significantly shorter in the posterior group than those in the anterior group (4.4 {+-} 0.8 cm and 1.8 {+-} 0.3 cm vs. 6.6 {+-} 0.9 cm and 2.8 {+-} 0.4 cm, p < 0.001), respectively. The incidence of contrast leakage was more frequent in the posterior group (p = 0.003). The posterior approach will be useful in shoulder MR arthrography with a suspected anterior pathology, a postoperative follow-up study or obese patient.

  20. Role Guided Intraperitoneal Port-A-Cath Insertion in The Managment of Cancer Ovary of Fluoroscopic

    Ahmed H Soliman *, Saad Ali Abd-Rabou *, Maged Abou Seada *,


    Full Text Available Introduction : The use of intraperitoneal (IP chemotherapy as a treatment for ovarian cancer has been demonstrated to result in improved survival. Aim of the work: The aim of this work is to evaluate the applicability and efficacy of fluoroscopic placed intraperitoneal port-A-cath and to assess the response rate to intraperitoneal chemotherapy in cases of ovarian carcinoma .Methods: The studied group included ,22 female patients with malignant ovarian cancer whom referred from gynecological surgery and gynecological oncology units to the Vascular and Interventional Radiology Unit, Ain Shams University Hospitals, for peritoneal port-A-cath application. All the patients were known cases of either primary or recurrent ovarian cancer , underwent cytoreductive surgery and referred to us .Results: Intraperitoneal port-A-cath with the aid of fluoroscopy showed highest technical success ( 91.9% and lowest complication rate on the long run compared to other methods of peritoneal access . Patients with cancer ovary showed significant improvement of the disease process denoted by changes in the degree of ascites , peritoneal nodules and tumor marker level after receiving combined IV/ IP chemotherapy. Conclusion: Port catheters proved to be the most safe method of long term access to the peritoneal cavity with the lowest complication rate compared to other methods of access to the peritoneal cavity

  1. Fine needle aspiration of focal lung lesion under CT fluoroscopic guidance

    Jeon, Hae Jeong; Shin, Hyun Joon; Choi, Young Chil; Park, Sang Woo; Yi, Jeong Geun; Park, Jeong Hee [College of Medicine, Konkuk University, Seoul (Korea, Republic of); Jin, Yong Hyun [Sung Ae Hospital, Seoul (Korea, Republic of)


    We wanted to assess the efficacy of using CT fluoroscopy during Fine Needle Aspiration (FNA) for focal lung lesion. We retrospectively reviewed 22 patients who had undergone FNA under CT fluoroscopic guidance. The final diagnosis of focal lung lesion was based on surgery, the results of biopsy taken from another site or the clinical diagnosis with imaging follow-up. We reviewed the imaging and recorded the location of the lesion, the lesion size and the depth from the puncture site. In 24 cases of 22 patients, 16 lesions were benign and 8 were malignant. The sensitivity and specificity for malignant lesions were 100%, and 75%, respectively. The mean size of the malignant lesions was 3.75 {+-} 1.68 cm, and that of the benign lesion was 3.05 {+-} 2.98 cm. The mean depth of the lesion divided by the size was 1.85 {+-} 1.09 for 20 lesions of the correct result group and 3.13 {+-} 1.73 for 4 lesions of the incorrect result group; the difference between the two groups was statistically different ({rho} = 0.030). The complications after FNA were pneumothoraces in three cases and parenchymal hemorrhage in one case, but no significant complication was noted after the procedures. We could perform the FNA accurately and safely under CT fluoroscopy guidance, so this technique can be used for FNA of focal lung lesion for obtaining a correct result with fewer complications.

  2. Comparison measurements of DQE for two flat panel detectors: fluoroscopic detector vs. cone beam CT detector

    Betancourt Benítez, Ricardo; Ning, Ruola; Conover, David


    The physical performance of two flat panel detectors (FPD) has been evaluated using a standard x-ray beam quality set by IEC, namely RQA5. The FPDs evaluated in this study are based on an amorphous silicon photodiode array that is coupled to a thallium-doped Cesium Iodide scintillator and to a thin film transistor (TFT) array. One detector is the PaxScan 2520 that is designed for fluoro imaging, and has a small dynamic range and a large image lag. The other detector is the PaxScan 4030CB that is designed for cone beam CT, and has a large dynamic range (>16-bit), a reduced image lag and many imaging modes. Varian Medical Systems manufactured both detectors. The linearity of the FPDs was investigated by using an ionization chamber and aluminum filtration in order to obtain the beam quality. Since the FPDs are used in fluoroscopic mode, image lag of the FPD was measured in order to investigate its effect on this study, especially its effect on DQE. The spatial resolution of the FPDs was determined by obtaining the pre-sampling modulation transfer function for each detector. A sharp edge was used in accordance to IEC 62220-1. Next, the Normalized Noise Power Spectrum (NNPS) was calculated for various exposures levels at RQA5 radiation quality. Finally, the DQE of each FPD was obtained with a modified version of the international standard set by IEC 62220-1. The results show that the physical performance in DQE and MTF of the PaxScan 4030CB is superior to that of PaxScan2520.

  3. Fluoroscopic and CT enteroclysis in children: initial experience, technical feasibility, and utility

    Brown, Shanaree [Indiana University School of Medicine, Indianapolis, IN (United States); University of Missouri, Department of Radiology, Columbia, MO (United States); Applegate, Kimberly E. [Riley Hospital for Children, Section of Pediatric Radiology, Indianapolis, IN (United States); Riley Hospital for Children, Department of Radiology, Indiana University School of Medicine, Indianapolis, IN (United States); Sandrasegaran, Kumar; Jennings, S.G.; Garrett, Joshua; Maglinte, Dean T. [Riley Hospital for Children, Department of Radiology, Indiana University School of Medicine, Indianapolis, IN (United States); Skantharajah, Arunan [Indiana University, Indianapolis, IN (United States)


    Partial small-bowel obstruction can be difficult to diagnose on clinical examination. These obstructions might not be detected on routine abdominal/pelvic CT. To evaluate the feasibility, safety, and techniques of fluoroscopic enteroclysis (FE) and CT enteroclysis (CTE), and to review their indications and findings in children. We retrospectively reviewed all enteroclysis studies in children younger than 18 years performed between January 2002 and March 2007. We correlated the results with other abdominal imaging and surgical and pathological findings. The review revealed 112 FE and 74 CTE studies performed in 175 children (mean age 14 years, range 3-18 years). FE and CTE studies were performed most commonly for evaluation of known Crohn disease (FE 38%, CTE 29%) and abdominal pain (FE 26%, CTE 26%). One FE study was terminated because of patient anxiety, and one CTE study was terminated because of patient discomfort. No complications of FE or CTE were reported. The findings were normal in 54% of the FE studies and 46% of the CTE studies. The most common small bowel diagnoses were Crohn disease (FE 34%, CTE 28%) and partial small bowel obstruction (FE 3%, CTE 10%). Two FE studies (2%) and 14 CTE studies (19%) showed abnormalities outside the small bowel. In 54 patients with inflammatory bowel disease, 11 FE studies and 25 CTE studies showed additional bowel abnormalities. Overall, 14 and 21 patients had surgery as a result of the findings of FE and CTE, respectively. FE and CTE are safe, feasible, and accurate in depicting small-bowel pathology in children. These techniques can be particularly useful in children with Crohn disease involving the small bowel. (orig.)

  4. Improved-resolution real-time skin-dose mapping for interventional fluoroscopic procedures

    Rana, Vijay K.; Rudin, Stephen; Bednarek, Daniel R.


    We have developed a dose-tracking system (DTS) that provides a real-time display of the skin-dose distribution on a 3D patient graphic during fluoroscopic procedures. Radiation dose to individual points on the skin is calculated using exposure and geometry parameters from the digital bus on a Toshiba C-arm unit. To accurately define the distribution of dose, it is necessary to use a high-resolution patient graphic consisting of a large number of elements. In the original DTS version, the patient graphics were obtained from a library of population body scans which consisted of larger-sized triangular elements resulting in poor congruence between the graphic points and the x-ray beam boundary. To improve the resolution without impacting real-time performance, the number of calculations must be reduced and so we created software-designed human models and modified the DTS to read the graphic as a list of vertices of the triangular elements such that common vertices of adjacent triangles are listed once. Dose is calculated for each vertex point once instead of the number of times that a given vertex appears in multiple triangles. By reformatting the graphic file, we were able to subdivide the triangular elements by a factor of 64 times with an increase in the file size of only 1.3 times. This allows a much greater number of smaller triangular elements and improves resolution of the patient graphic without compromising the real-time performance of the DTS and also gives a smoother graphic display for better visualization of the dose distribution.

  5. A Study of Occupational Radiation Dosimetry During Fluoroscopically Guided Simulated Urological Surgery in the Lithotomy Position.

    Horsburgh, Ben A; Higgins, Mike


    To quantify through environmental audit the radiation dose that urologists receive during surgery in the lithotomy position, and to quantify the dose reduction achieved by altering exposure techniques and personal protective equipment use. Simulated surgery in the lithotomy position using an anthropomorphic phantom as a patient and a SimMan(®) mannequin as the surgeon. Pulsed fluoroscopy, focus-to-skin distance (FSD), collimation, and addition of a lead shield at the table end were individually and collectively introduced after a control study. Scattered X-ray dose rates to the simulated surgeon's eye, thyroid, trunk, external genitalia, and leg were measured with each of the technique adjustments. The absorbed dose in air at the phantom skin was measured throughout. Results were compared to discover surgeon dose rates with technique alteration. Increasing FSD leads to a rise in surgeon eye dose, and table end lead protection increases the patient skin dose. Use of all the dose-reduction techniques together reduces the dose to the patient, and a surgeon's trunk dose is decreased by 95%, external genitalia dose by 99%, and leg dose by 97%. Sitting to perform fluoroscopically guided surgery in the lithotomy position increases surgeon dose by a median value of 17%, with the external genitalia dose increased by 78% compared with the standing position. This study describes effective methods of dose reduction that are easy to instigate. The resulting reduction in radiation dose during urology procedures meets the requirements of international guidelines and legislation. This change in practice improves patient care and reduces risk to urologists from occupational exposure to radiation. By combining all of the dose-reduction techniques, urologists should never reach the threshold for deterministic radiation effects to their eyes during their career, and they will have a significantly lower chance of stochastic risks such as cancer.

  6. Benefit of fluoroscopically guided intraarticular, long-acting corticosteroid injection for subtalar arthritis in juvenile idiopathic arthritis

    Cahill, Anne M.; Cho, Sandy S. [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Baskin, Kevin M. [Children' s Hospital of Philadelphia, Department of Pediatrics, Division of Rheumatology, Philadelphia, PA (United States); Beukelman, Timothy; Cron, Randy Q. [Children' s Hospital of Pittsburgh, Department of Radiology, Pittsburgh, PA (United States); Kaye, Robin D. [Children' s Hospital of Wisconsin, Department of Radiology, Milwaukee, WI (United States); Towbin, Richard B.


    Children with arthritis may endure a lifetime of disfigurement, dysfunction, and pain if acute inflammation progresses to chronic changes in the joint cartilage and underlying bone. Intraarticular steroids have become an integral component of treatment, but at times are difficult to deliver to joints, such as the subtalar joint, that have complex anatomies. We describe our technique and outcomes using fluoroscopically guided intraarticular subtalar steroid injection in patients with active symptoms of juvenile idiopathic arthritis (JIA). Fluoroscopically guided subtalar joint injections were performed in 38 children (mean age 6.7 years). Medical records were reviewed retrospectively and improvement was evaluated clinically by the degree of foot movement in eversion and inversion. Subtalar joint injection was technically successful in 100% of the JIA patients with improvement in physical symptoms in 34/38 (89%). Of the 38 children, 32 were followed up within 13 weeks of the initial injection and, therefore, satisfied the eligibility criteria for resolution of arthritis. Of these 32 children, 14 showed clinical resolution (44%). The mean duration of improvement was 1.2 {+-} 0.9 years. Children with a longer interval (>1 year) from diagnosis to treatment had significantly less resolution (P = 0.04). Local subcutaneous atrophy or hypopigmentation were observed in 53% of the children after steroid injection (20/38). These minor complications were associated with a greater volume of steroid injected into the site per child (P = 0.02). Fluoroscopically guided subtalar joint injection is an effective treatment for subtalar arthropathy. Prompt referral for intraarticular steroid treatment in the acute phase improves response. Skin changes often occur at the injection site, and specific precautions should be employed to reduce this risk. Prospective study is indicated to determine the most effective treatment strategy to prevent long-term pain and disability. (orig.)

  7. SU-E-J-126: Generation of Fluoroscopic 3D Images Using Single X-Ray Projections on Realistic Modified XCAT Phantom Data.

    Mishra, P; Li, R; St James, S; Yue, Y; Mak, R; Berbeco, R; Lewis, J


    To simulate the process of generating fluoroscopic 3D treatment images from 4DCT and measured 2D x-ray projections using a realistic modified XCAT phantom based on measured patient 3D tumor trajectories. First, the existing XCAT phantom is adapted to incorporate measured patient lung tumor trajectories. Realistic diaphragm and chest wall motion are automatically generated based on input tumor motion and position, producing synchronized, realistic motion in the phantom. Based on 4DCT generated with the XCAT phantom, we derive patient-specific motion models that are used to generate 3D fluoroscopic images. Patient-specific models are created in two steps: first, the displacement vector fields (DVFs) are obtained through deformable image registration of each phase of 4DCT with respect to a reference image (typically peak-exhale). Each phase is registered to the reference image to obtain (n-1) DVFs. Second, the most salient characteristics in the DVFs are captured in a compact representation through principal component analysis (PCA). Since PCA is a linear decomposition method, all the DVFs can be represented as linear combinations of eigenvectors. Fluoroscopic 3D images are obtained using the projection image to determine optimal weights for the eigenvectors. These weights are determined through iterative optimization of a cost function relating the projection image to the 3D image via the PCA lung motion model and a projection operator. Constructing fluoroscopic 3D images is thus reduced to finding optimal weights for the eigenvectors. Fluoroscopic 3D treatment images were generated using the modified XCAT phantom. The average relative error of the reconstructed image over 30 sec is 0.0457 HU and the standard deviation is 0.0063. The XCAT phantom was modified to produce realistic images by incorporating patient tumor trajectories. The modified XCAT phantom can be used to simulate the process of generating fluoroscopic 3D treatment images from 4DCT and 2D x

  8. Evaluation of the microangiographic fluoroscope (MAF) using generalized system performance metrics

    Jain, Amit [Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York 14214 (United States); Bednarek, Daniel R. [Toshiba Stroke and Vascular Research Center, Department of Radiology, Department of Neurosurgery, and Department of Physiology and Biophysics, University at Buffalo, State University of New York, Buffalo, New York 14214 (United States); Rudin, Stephen [Toshiba Stroke and Vascular Research Center, Department of Radiology, Department of Neurosurgery, Department of Physiology and Biophysics, Department of Mechanical and Aerospace Engineering, Department of Electrical Engineering, and Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, New York 14214 (United States)


    Purpose: The performance of a newly developed, high resolution, microangiographic fluoroscope (MAF) (35 {mu}m pixel pitch and 300 {mu}m thick CsI phosphor) was evaluated using a generalized linear system analysis and compared with that of a standard amorphous Si thin film transistor flat panel detector (FPD) (194 {mu}m pixel pitch and 600 {mu}m thick CsI phosphor). The linear system metrics such as modulation transfer function (MTF), noise power spectrum, and detection quantum efficiency (DQE) are commonly used to gauge the intrinsic detector performance in the detector plane. However, these linear system metrics do not provide information about the image receptor performance in a real system since they do not include the effects of other parameters such as focal spot distribution, scatter radiation, and geometric unsharpness, which may compromise detector performance characteristics. Use of generalized linear system metrics [generalized modulation transfer function (GMTF), generalized normalized noise power spectrum (GNNPS), and generalized detection quantum efficiency (GDQE)] that include these effects gives a more meaningful, complete, and appropriate evaluation of detector performance as part of the imaging system. Methods: A uniform head equivalent phantom was used to simulate realistic clinical parameters and x-ray spectra. The detector MTFs were measured using the slanted edge method and the focal spot MTFs were measured using a pinhole assembly. The scatter MTF was simulated and the scatter fraction was measured for a head-equivalent phantom. The generalized system metrics were calculated for different combinations of three choices of focal spots and three different magnifications with two different air-gaps. The performance of the MAF was also illustrated using stent images obtained with different focal spots under similar conditions. Results: Results for the generalized metrics provide a quantitative description of the performance of the imaging system

  9. Magnetic Resonance Enterography Findings in Crohn's disease in the Pediatric Population and Correlation with Fluoroscopic and Multidetector Computed Tomographic Techniques.

    Patel, Parul; Ormanoski, Margaret; Hoadley, Kim M


    Traditionally, fluoroscopic examinations such as enteroclysis, upper GI studies, and small bowel follow through exams have been the procedures of choice in evaluating inflammatory bowel disease (IBD) in pediatric populations. With the advent of multidetector computed tomography (MDCT), it has subsequently become a complementary examination in imaging inflammatory bowel disease. A major advantage of MDCT over fluoroscopic examination is its ability to directly visualize bowel mucosa, as well as demonstrate extra-enteric complications of IBD such as abscesses, fistulae, and sinus tracts. The major disadvantage of CT however is exposure to ionizing radiation, especially in IBD patients of the pediatric age group who maybe repeatedly imaged due to exacerbations. As a result, magnetic resonance enterography (MRE) is becoming increasingly important in the evaluation and follow-up of pediatric patients with IBD. This pictorial essay will summarize the multi-modality imaging findings of IBD with emphasis on MRE including the imaging protocol and procedure. For the purposes of this article, patients less than 17 years of age have been considered to represent the pediatric population.

  10. Fluoroscopically guided fallopian tube recanalization with a simplified set of instruments; Durchleuchtungsgesteuerte Eileiter-Rekanalisation mit vereinfachtem Instrumentarium

    Schmitz-Rode, T.; Guenther, R.W. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Neulen, J. [Technische Hochschule Aachen (Germany). Frauenklinik fuer gynaekologische Endokrinologie und Reproduktionsmedizin


    Purpose: Fluoroscopically guided transcervical fallopian tube recanalization is recognized as an important step in the workup of female infertility. In the present study, a simplified set of recanalization instruments was tested. Materials and Methods: Forty-two women with infertility and sonographically confirmed or suspected uni- or bilateral tubal occlusion were examined. After vaginal placement of a plastic speculum and fixation of a tenaculum, a 4F glide catheter with a 0.89 mm glidewire was advanced transcervically. After documentation of tubal occlusion by hysterosalpingography, the uterotubal junction was catheterized with the same instruments. Under fluoroscopic guidance, the glidewire was negotiated beyond the intramural portion of the tube. Selective salpingography documented the outcome of the recanalization. Results: Hysterosalpingography confirmed tubal occlusions in 26 of 42 patients (in 12 cases unilateral and in 14 cases bilateral). Fallopian tube recanalization was successful in 23 of 26 patients (technical success rate of 88%). The resulting fertility rate was 30% (7/23), without any ectopic pregnancy. Complications such as tubal perforation, infection, or bleeding did not occur. Tubal catheterization was straightforward and smooth in 17/23 cases. For a hyperflexed uterus (6/23), a curved tip of the catheter was helpful in tubal probing. (orig.)

  11. Fluoroscopic Analysis of Tibial Translation in Anterior Cruciate Ligament Injured Knees With and Without Bracing During Forward Lunge



    Full Text Available Background Despite several studies with different methods, the effect of functional knee braces on knee joint kinematics is not clear. Direct visualization of joint components through medical imaging modalities may provide the clinicians with more useful information. Objectives In this study, for the first time in the literature, video fluoroscopy was used to investigate the effect of knee bracing on the sagittal plane kinematics of anterior cruciate ligament (ACL injured patients. Patients and Methods For twelve male unilateral ACL deficient subjects, the anterior tibial translation was measured during lunge exercise in non-braced and braced conditions. Fluoroscopic images were acquired from the subjects using a digital fluoroscopy system with a rate of 10 fps. The image of each frame was scaled using a calibration coin and analyzed in AutoCAD environment. The angle between the two lines, tangent to the posterior cortexes of the femoral and tibial shafts was measured as the flexion angle. For the fluoroscopic images associated with 0°, 15°, 30°, 45° and 60° knee flexion angles, the relative anterior-posterior configuration of the tibiofemoral joint was assessed by measuring the position of landmarks on the tibia and femur. Results Results indicated that the overall anterior translations of the tibia during the eccentric (down and concentric (up phases of lunge exercise were 10.4 ± 1.7 mm and 9.0 ± 2.2 mm for non-braced, and 10.1 ± 3.4 mm and 7.4 ± 2.5 mm, for braced conditions, respectively. The difference of the tibial anterior-posterior translation behaviors of the braced and non-braced knees was not statistically significant. Conclusion Fluoroscopic imaging provides an effective tool to measure the dynamic behavior of the knee joint in the sagittal plane and within the limitations of this study, the pure mechanical stabilizing effect of functional knee bracing is not sufficient to control the anterior tibial translation of the ACL

  12. SU-E-J-01: 3D Fluoroscopic Image Estimation From Patient-Specific 4DCBCT-Based Motion Models

    Dhou, S; Hurwitz, M; Lewis, J [Brigham and Women' s Hospital, Dana-Farber Cancer Center, Harvard Medical School, Boston, MA (United States); Mishra, P [Varian Medical Systems, Palo Alto, CA (United States)


    Purpose: 3D motion modeling derived from 4DCT images, taken days or weeks before treatment, cannot reliably represent patient anatomy on the day of treatment. We develop a method to generate motion models based on 4DCBCT acquired at the time of treatment, and apply the model to estimate 3D time-varying images (referred to as 3D fluoroscopic images). Methods: Motion models are derived through deformable registration between each 4DCBCT phase, and principal component analysis (PCA) on the resulting displacement vector fields. 3D fluoroscopic images are estimated based on cone-beam projections simulating kV treatment imaging. PCA coefficients are optimized iteratively through comparison of these cone-beam projections and projections estimated based on the motion model. Digital phantoms reproducing ten patient motion trajectories, and a physical phantom with regular and irregular motion derived from measured patient trajectories, are used to evaluate the method in terms of tumor localization, and the global voxel intensity difference compared to ground truth. Results: Experiments included: 1) assuming no anatomic or positioning changes between 4DCT and treatment time; and 2) simulating positioning and tumor baseline shifts at the time of treatment compared to 4DCT acquisition. 4DCBCT were reconstructed from the anatomy as seen at treatment time. In case 1) the tumor localization error and the intensity differences in ten patient were smaller using 4DCT-based motion model, possible due to superior image quality. In case 2) the tumor localization error and intensity differences were 2.85 and 0.15 respectively, using 4DCT-based motion models, and 1.17 and 0.10 using 4DCBCT-based models. 4DCBCT performed better due to its ability to reproduce daily anatomical changes. Conclusion: The study showed an advantage of 4DCBCT-based motion models in the context of 3D fluoroscopic images estimation. Positioning and tumor baseline shift uncertainties were mitigated by the 4DCBCT

  13. X-ray fluoroscopic observation of slag foaming; Slag no awadachi gensho no x sen toshi kansatsu

    Ogawa, Y.; Tokumitsu, N. [Nippon Steel Corp., Tokyo (Japan)


    Slag foaming caused by slag/metal reaction in a graphite crucible was observed with X-ray fluoroscopic apparatus in order to make clear the effect of bubble size on the foam height and the distribution of bubbles in slag. It was observed that the foam layer was formed when CO bubbles evolved at slag/metal interface became less than approximately 2mm in diameter. The foam height increased with the decrease of bubble size even in case of almost the same gas evolution rate. The size of bubbles decreased with the increase of iron oxide Content in slag and the decrease of sulphur content. It is considered that the bubbles become smaller when slag is wettable with metal. Therefore, the physical properties of slag/metal interface also affect the foam height besides the surface tension or viscosity of slag because they change the bubble size. (author)

  14. Google Glass as an Alternative to Standard Fluoroscopic Visualization for Percutaneous Fixation of Hand Fractures: A Pilot Study.

    Chimenti, Peter C; Mitten, David J


    This pilot study investigated the feasibility of Google Glass to assist visualization of fluoroscopic images during percutaneous pinning of hand fractures. Cadavers were used to compare total time to pin each fracture and total number of radiographs per fracture from a mini C-arm. A FluoroScan monitor was used for radiographic visualization compared to projecting the images in the Google Glass display. All outcome measures significantly improved for proximal phalanx fractures (127 versus 86 seconds, p = 0.017; 5.3 versus 2.2 images, p = 0.003), and fewer images were obtained during fixation of metacarpal fractures using Google Glass compared with traditional techniques (6.4 versus 3.6, p Google Glass allows constant attention directed toward the operative field.

  15. Placement of subcutaneous ureteral bypasses without fluoroscopic guidance in cats with ureteral obstruction: 19 cases (2014-2016).

    Livet, Véronique; Pillard, Paul; Goy-Thollot, Isabelle; Maleca, David; Cabon, Quentin; Remy, Denise; Fau, Didier; Viguier, Éric; Pouzot, Céline; Carozzo, Claude; Cachon, Thibaut


    The purpose of this study was to describe the perioperative and postoperative complications as well as short-term and long-term outcomes in cats with ureteral obstructions treated by placement of a subcutaneous ureteral bypass (SUB) device without imaging control. The second objective of this study was to compare cats treated by SUB device with cats treated by traditional surgical intervention. Data were obtained retrospectively from the medical records (2014-2016) of cats that underwent SUB placement (SUB cats) and cats that underwent traditional ureteral surgery (C cats). Nineteen SUB devices were placed without fluoroscopic, radiographic or ultrasonographic guidance in 13 cats. Fifteen traditional interventions (ureterotomy and neoureterocystostomy) were performed in 11 cats. Successful placement of the SUB device was achieved in all cats with only one major intraoperative complication (kinking of the kidney catheter) and one minor intraoperative complication (misplacement of the kidney catheter). Eleven SUB cats recovered from the surgical procedure; two SUB cats and three C cats died during the anaesthesia recovery period. Postoperative SUB complications included anaemia (n = 2), urinary tract infection (UTI) (n = 4), non-infectious cystitis (n = 5) and SUB device obstruction (n = 1). Postoperative traditional surgery complications included anaemia (n = 7), UTIs (n = 6), non-infectious cystitis (n = 1), re-obstruction (n = 4) and ureteral stricture (n = 1). Median postoperative duration of hospitalisation (3 days) was significantly shorter for SUB cats than for C cats (P = 0.013). Ten SUB cats (76.9%) and four C cats (40%) were still alive at a median follow-up of 225 days and 260 days, respectively. Owners were completely (90%) or mostly (10%) satisfied with the SUB device placement. SUB device placement appears to be an effective and safe option for treating ureteral obstruction in cats, and this study has shown that fluoroscopic guidance is not essential in

  16. Feasibility of differential quantification of 3D temporomandibular kinematics during various oral activities using a cone-beam computed tomography-based 3D fluoroscopic method

    Chien-Chih Chen


    Conclusion: A new CBCT-based 3D fluoroscopic method was proposed and shown to be capable of quantitatively differentiating TMJ movement patterns among complicated functional activities. It also enabled a complete description of the rigid-body mandibular motion and descriptions of as many reference points as needed for future clinical applications. It will be helpful for dental practice and for a better understanding of the functions of the TMJ.

  17. Multiplanar reformat and volume rendering of a multidetector CT scan for path planning a fluoroscopic procedure on Gasserian ganglion block - a preliminary report

    Horiguchi, Jun; Ishifuro, Minoru; Fukuda, Hiroshi; Akiyama, Yuji; Ito, Katsuhide


    In the treatment of trigeminal neuralgia, Gasserian block under fluoroscopical guidance may be difficult because of anatomic variability, and difficulty in identification of the foramen ovale. We introduce how to use three-dimensional CT in the preprocedural planning. We determine the skull-rotation angle in which the foramen ovale is best visualized, the relationship (distance, angle) between the virtual puncture point and anatomical landmarks, and the distance between the virtual puncture point and the foramen.

  18. Comparison of MR and fluoroscopic mucous fistulography in the pre-operative evaluation of infants with anorectal malformation: a pilot study

    Alves, Jose C.G.; Lotz, Jan W.; Pitcher, Richard D. [Stellenbosch University, Division of Radiodiagnosis, Department of Medical Imaging and Clinical Oncology, Tygerberg Academic Hospital, Cape Town (South Africa); Sidler, Daniel [Stellenbosch University, Division of Pediatric Surgery, Department of Surgical Sciences, Tygerberg Academic Hospital, Cape Town (South Africa)


    Anorectal malformations are often associated with rectal pouch fistulas. Surgical correction requires accurate evaluation of the presence and position of such fistulas. Fluoroscopy is currently the chosen modality for the detection of fistulas. The role of MRI is unexplored. To compare the diagnostic accuracy of MR versus fluoroscopic fistulography in the pre-operative evaluation of infants with anorectal malformation. We conducted a pilot study of infants requiring defunctioning colostomy for initial management of anorectal malformation. Dynamic sagittal steady-state free-precession MRI of the pelvis was acquired during introduction of saline into the mucous fistulas. Findings were compared among MR fistulography, fluoroscopic fistulography and intraoperative inspection. Eight children were included. Median age at fistulography was 15 weeks, inter-quartile range 13-20 weeks; all were boys. There was full agreement among MR fistulography, fluoroscopic fistulography and surgical findings. The pilot data suggest that MR fistulography is promising in the pre-operative evaluation of children with anorectal malformation. (orig.)

  19. Fluoroscopic-guided supra-scapular nerve block in the management of shoulder pain in a Nigerian Teaching Hospital: Report of five cases

    Zakari Aliyu Suleiman


    Full Text Available Shoulder pain complaints are common in our environment. The disorder can occur among the young active age group or in the older patients as a result of degenerative changes with its attendant limitations of the function of the affected upper limb, hindrance of the performance of activities of daily living, and reduced quality of life. The traditional oral analgesics, physiotherapy, and intra-articular corticosteroid injections are seldom ineffective at providing the desired pain relief and functional improvement at the shoulder joint. We investigated the role of fluoroscopic-guided supra-scapular nerve blocks (SSNBs in patients with shoulder pain who failed to respond to the routine conservative management. With the patient lying prone and the C-arm fluoroscope placed in anterior-posterior position, the scapula notch was visualized and a 22G spinal needle was directed toward the nerve. The mixture of local anesthetic agent and steroid was injected as close to the nerve as possible after negative aspiration. Fluoroscopic-guided SSNB can produce substantial pain relief and improved range of movement in patients with painful shoulders. The procedure is safe, well tolerated, and can be done on a day-case basis.

  20. Thyroid, parathyroid, and salivary gland evaluations in patients exposed to multiple fluoroscopic examinations during tuberculosis therapy: a pilot study

    Kaplan, M.M.; Boice, J.D. Jr.; Ames, D.B.; Rosenstein, M.


    The prevalence of thyroid, parathyroid, and salivary abnormalities was determined in 91 women who received an average of 112 fluoroscopic chest examinations during pneumothorax treatment for tuberculosis more than 40 yr previously and in 72 women treated for tuberculosis by other modalities. Thyroid abnormalities were determined by physical examination, scintiscans, and measurements of serum free T4 index, TSH, and thyroid microsomal antibodies. Thyroid nodules were diagnosed in 7.7% of the exposed and 4.2% of the comparison group (prevalence ratio, 1.8; 90% confidence interval 0.6-5.7). Autoimmune thyroid disease was diagnosed in 15.2% of the exposed and 6.9% of the comparison group (prevalence ratio, 2.2; 95% confidence interval, 0.8-6.2). No salivary tumors were detected. Two exposed women and 1 comparison woman had primary hyperparathyroidism. Although absorbed dose to the thyroid could not be precisely determined, approximately 60 rads would be expected to yield the observed excess of thyroid nodules. While the prevalence ratios were not significantly increased in the exposed group, the results suggest that susceptibility of the thyroid to nodules from cumulative radiation doses of this magnitude could be increased even when the doses are accumulated over years and that such x-ray exposure of the thyroid gland may predispose the patient to the development of autoimmune disease.

  1. Rehabilitation after ACL Injury: A Fluoroscopic Study on the Effects of Type of Exercise on the Knee Sagittal Plane Arthrokinematics

    Sadegh Norouzi


    Full Text Available A safe rehabilitation exercise for anterior cruciate ligament (ACL injuries needs to be compatible with the normal knee arthrokinematics to avoid abnormal loading on the joint structures. The objective of this study was to measure the amount of the anterior tibial translation (ATT of the ACL-deficient knees during selective open and closed kinetic chain exercises. The intact and injured knees of fourteen male subjects with unilateral ACL injury were imaged using uniplanar fluoroscopy, while the subjects performed forward lunge and unloaded/loaded open kinetic knee extension exercises. The ATTs were measured from fluoroscopic images, as the distance between the tibial and femoral reference points, at seven knee flexion angles, from 0° to 90°. No significant differences were found between the ATTs of the ACL-deficient and intact knees at all flexion angles during forward lunge and unloaded open kinetic knee extension (. During loaded open kinetic knee extension, however, the ATTs of the ACL deficient knees were significantly larger than those of the intact knees at 0° (. It was suggested that the forward lunge, as a weight-bearing closed kinetic chain exercise, provides a safer approach for developing muscle strength and functional stability in rehabilitation program of ACL-deficient knees, in comparison with open kinetic knee extension exercise.

  2. Transverse morphology of the sacroiliac joint: effect of angulation and implications for fluoroscopically guided sacroiliac joint injection

    Ling, B.C.; Lee, J.W.; Man, H.S.J.; Grace, M.G.A.; Lambert, R.G.W. [Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, Edmonton (Canada); Jhangri, G.S. [Department of Public Health Sciences, University of Alberta Hospital, Edmonton (Canada)


    Effects of angulation of computed tomography (CT) reconstruction plane on sacroiliac (SI) joint morphology were studied, and factors influencing the approach to fluoroscopically guided SI joint injection were assessed. CT scans of pelvises were reformatted on 41 subjects, aged 51.7 ({+-}15.1) years. Transverse images were reconstructed at the caudal 3 cm of the SI joint tilting plane of reconstruction from -30 to +30 at 15 increments. Anteroposterior diameter of joint (depth), angle from sagittal plane (orientation angle), and distance from skin were measured. Joint contour was classified, and presence of bone blocking access to the joint was recorded. Comparison between angles were analysed by t-test. Relationships between variables were assessed by a Pearson correlation test. Depth was shorter with angulation in the inferior direction (P<0.01). Orientation angle increased with superior angulation (P<0.01). Distance from skin increased (P<0.01) with angulation in either direction. Joint contour was significantly different from baseline at each angle (P<0.001) but highly variable. Inferior angulation resulted in interposition of ilium between skin and SI joint, and superior angulation caused bone block due to the lower sacrum. None of these features was identified without tilting of the reconstruction plane, and effects were more pronounced with steeper angulation.

  3. Closed reduction and fluoroscopic-assisted percutaneous pinning of 42 physeal fractures in 37 dogs and 4 cats.

    Boekhout-Ta, Christina L; Kim, Stanley E; Cross, Alan R; Evans, Richard; Pozzi, Antonio


    To report complications and clinical outcome of dogs and cats that underwent fluoroscopic-assisted percutaneous pinning (FAPP) of physeal fractures. Retrospective study. Client-owned dogs (n = 37) and cats (n = 4). Records (August 2007-August 2014) of physeal fractures treated with FAPP in 3 hospitals were evaluated. Data collected included signalment, fracture characteristics (etiology, location, duration, Salter-Harris classification, preoperative and postoperative displacement), surgical information (implant size, surgical duration), and outcome assessment information (functional outcome, radiographic outcome, and complications). The majority of animals (92%) were classified as full functional outcome. No significant predictors of functional outcome were identified. The overall complication rate was 15% (n = 6). Elective pin removal rate was 41% (n = 17). Goniometry and limb circumference measurements of the affected and contralateral limbs were not significantly different in dogs for which measurements were obtained. Seventeen of 18 animals (16 dogs, 2 cats) measured had bone length changes on follow-up radiographs. FAPP is associated with an excellent functional outcome in a narrow selection of fracture configurations, specifically those with minimal displacement and for which anatomical alignment can be achieved with closed reduction. © 2016 The American College of Veterinary Surgeons.

  4. Three-dimensional kinematic estimation of mobile-bearing total knee arthroplasty from x-ray fluoroscopic images

    Yamazaki, Takaharu; Futai, Kazuma; Tomita, Tetsuya; Sato, Yoshinobu; Yoshikawa, Hideki; Tamura, Shinichi; Sugamoto, Kazuomi


    To achieve 3D kinematic analysis of total knee arthroplasty (TKA), 2D/3D registration techniques, which use X-ray fluoroscopic images and computer-aided design (CAD) model of the knee implant, have attracted attention in recent years. These techniques could provide information regarding the movement of radiopaque femoral and tibial components but could not provide information of radiolucent polyethylene insert, because the insert silhouette on X-ray image did not appear clearly. Therefore, it was difficult to obtain 3D kinemaitcs of polyethylene insert, particularly mobile-bearing insert that move on the tibial component. This study presents a technique and the accuracy for 3D kinematic analysis of mobile-bearing insert in TKA using X-ray fluoroscopy, and finally performs clinical applications. For a 3D pose estimation technique of the mobile-bearing insert in TKA using X-ray fluoroscopy, tantalum beads and CAD model with its beads are utilized, and the 3D pose of the insert model is estimated using a feature-based 2D/3D registration technique. In order to validate the accuracy of the present technique, experiments including computer simulation test were performed. The results showed the pose estimation accuracy was sufficient for analyzing mobile-bearing TKA kinematics (the RMS error: about 1.0 mm, 1.0 degree). In the clinical applications, seven patients with mobile-bearing TKA in deep knee bending motion were studied and analyzed. Consequently, present technique enables us to better understand mobile-bearing TKA kinematics, and this type of evaluation was thought to be helpful for improving implant design and optimizing TKA surgical techniques.

  5. MO-F-CAMPUS-I-01: A System for Automatically Calculating Organ and Effective Dose for Fluoroscopically-Guided Procedures

    Xiong, Z; Vijayan, S; Rana, V; Rudin, S; Bednarek, D [Toshiba Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY (United States)


    Purpose: A system was developed that automatically calculates the organ and effective dose for individual fluoroscopically-guided procedures using a log of the clinical exposure parameters. Methods: We have previously developed a dose tracking system (DTS) to provide a real-time color-coded 3D- mapping of skin dose. This software produces a log file of all geometry and exposure parameters for every x-ray pulse during a procedure. The data in the log files is input into PCXMC, a Monte Carlo program that calculates organ and effective dose for projections and exposure parameters set by the user. We developed a MATLAB program to read data from the log files produced by the DTS and to automatically generate the definition files in the format used by PCXMC. The processing is done at the end of a procedure after all exposures are completed. Since there are thousands of exposure pulses with various parameters for fluoroscopy, DA and DSA and at various projections, the data for exposures with similar parameters is grouped prior to entry into PCXMC to reduce the number of Monte Carlo calculations that need to be performed. Results: The software developed automatically transfers data from the DTS log file to PCXMC and runs the program for each grouping of exposure pulses. When the dose from all exposure events are calculated, the doses for each organ and all effective doses are summed to obtain procedure totals. For a complicated interventional procedure, the calculations can be completed on a PC without manual intervention in less than 30 minutes depending on the level of data grouping. Conclusion: This system allows organ dose to be calculated for individual procedures for every patient without tedious calculations or data entry so that estimates of stochastic risk can be obtained in addition to the deterministic risk estimate provided by the DTS. Partial support from NIH grant R01EB002873 and Toshiba Medical Systems Corp.

  6. Changes in length of the plantar aponeurosis during the stance phase of gait--an in vivo dynamic fluoroscopic study.

    Fessel, G; Jacob, H A C; Wyss, Ch; Mittlmeier, Th; Müller-Gerbl, M; Büttner, A


    In locomotion, ligaments and muscles have been recognized to support the arch of the foot. However, it remains unclear to what extent the passive and active structures of the lower extremity support the longitudinal arch of the foot during walking. In this study, the mechanical function of the plantar aponeurosis (PA) is investigated by elongation measurements in vivo during the stance phase of gait, in combination with measurements of the mechanical properties of the PA in vitro. Fluoroscopy was used to measure the dynamic changes in PA length and the angular motion of the metatarsophalangeal joint of the first ray, measured during the stance phase (StPh) in 11 feet. Simultaneously, ground forces were measured. Additionally, four cadaver feet delivered topographic information relating to the PA, and three autopsy specimens of PA served to determine the in vitro mechanical properties of PA. The present study revealed a non-significant peak average PA shortening of 0.48% at about 32.5% StPh, followed by a significant average peak elongation of 3.6% at 77.5% StPh. This average peak elongation of 3.6% corresponds to a force of 292N, as estimated by mechanical testing of the autopsy PA specimens. Considering the maximum peak elongation measured in one volunteer of 4.8% at 76% StPh, a peak PA load of 488N might be expected. Hence, with an average body weight of 751N, as allocated to the 11 investigated feet, this maximum peak force would correspond to about 0.65×body weight. As far as we are aware, this is the first report on a dynamic fluoroscopic study of the PA in gait with an appreciable number of feet (11 feet). In conclusion, muscles contribute to support of the longitudinal arch of the foot and can possibly relax the PA during gait. The 'windlass effect' for support of the arch in this context is therefore questionable.

  7. Large or small bore, push or pull: a comparison of three classes of percutaneous fluoroscopic gastrostomy catheters.

    Kuo, Yuo-Chen; Shlansky-Goldberg, Richard D; Mondschein, Jeffrey I; Stavropoulos, S William; Patel, Aalpen A; Solomon, Jeffrey A; Soulen, Michael C; Kwak, Andrew; Itkin, Maxim; Chittams, Jesse L; Trerotola, Scott O


    To compare the tube performance and complication rates of small-bore, large-bore push-type, and large-bore pull-type gastrostomy catheters. A total of 160 patients (74 men, 86 women; mean age, 66.9 years, range, 22-95 y) underwent percutaneous fluoroscopic gastrostomy placement between January 2004 and March 2006. Choice of catheter was based on the preference of the attending radiologist. Data were collected retrospectively with institutional review board approval. Radiology reports provided information on the catheter, indication for gastrostomy, technical success, and immediate outcome. Chart review provided data on medical history, postprocedural complications, progress to feeding goal, and clinical outcomes. Statistical analysis was performed to compare the three classes of gastrostomy catheters. All 160 catheters were placed successfully. Patients who received small-bore catheters (14 F; n = 88) had significantly more tube complications (17% vs 5.6%) and were less likely to meet their feeding goal (P = .035) compared with patients with large-bore catheters (20 F; n = 72). No difference was observed in terms of major or minor complications. Large-bore push-type (n = 14) and pull-type catheters (n = 58) were similar in terms of complication rates. Patients who received large-bore push-type catheters achieved their feeding goals in significantly less time than those with large-bore pull-type catheters (average, 3.8 days vs 6.0 days; P = .04). Patients who received small-bore gastrostomy catheters are significantly more prone to tube dysfunction. Large-bore catheters should be preferentially used, with push-type catheters performing better with regard to the time to achieve feeding goal.

  8. Incorporating Corrections for the Head-Holder and Compensation Filter when Calculating Skin Dose during Fluoroscopically-Guided Interventions

    Vijayan, Sarath; Rana, Vijay K.; Rudin, Stephen; Bednarek, Daniel R.


    The skin dose tracking system (DTS) that we developed provides a color-coded illustration of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures for immediate feedback to the interventionist. To improve the accuracy of dose calculation, we now have incorporated two additional important corrections (1) for the holder used to immobilize the head in neuro-interventions and (2) for the built-in compensation filters used for beam equalization. Both devices have been modeled in the DTS software so that beam intensity corrections can be made. The head-holder is modeled as two concentric hemi-cylindrical surfaces such that the path length between those surfaces can be determined for rays to individual points on the skin surface. The head-holder on the imaging system we used was measured to attenuate the primary x-rays by 10 to 20% for normal incidence, and up to 40% at non-normal incidence. In addition, three compensation filters of different shape are built into the collimator apparatus and were measured to have attenuation factors ranging from 58% to 99%, depending on kVp and beam filtration. These filters can translate and rotate in the beam and their motion is tracked by the DTS using the digital signal from the imaging system. When it is determined that a ray to a given point on the skin passes through the compensation filter, the appropriate attenuation correction is applied. These corrections have been successfully incorporated in the DTS software to provide a more accurate determination of skin dose. PMID:26819488

  9. Incorporating corrections for the head-holder and compensation filter when calculating skin dose during fluoroscopically guided interventions

    Vijayan, Sarath; Rana, Vijay K.; Rudin, Stephen; Bednarek, Daniel R.


    The skin dose tracking system (DTS) that we developed provides a color-coded illustration of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures for immediate feedback to the interventionist. To improve the accuracy of dose calculation, we now have incorporated two additional important corrections (1) for the holder used to immobilize the head in neuro-interventions and (2) for the built-in compensation filters used for beam equalization. Both devices have been modeled in the DTS software so that beam intensity corrections can be made. The head-holder is modeled as two concentric hemi-cylindrical surfaces such that the path length between those surfaces can be determined for rays to individual points on the skin surface. The head-holder on the imaging system we used was measured to attenuate the primary x-rays by 10 to 20% for normal incidence, and up to 40% at non-normal incidence. In addition, three compensation filters of different shape are built into the collimator apparatus and were measured to have attenuation factors ranging from 58% to 99%, depending on kVp and beam filtration. These filters can translate and rotate in the beam and their motion is tracked by the DTS using the digital signal from the imaging system. When it is determined that a ray to a given point on the skin passes through the compensation filter, the appropriate attenuation correction is applied. These corrections have been successfully incorporated in the DTS software to provide a more accurate determination of skin dose.

  10. Incorporating Corrections for the Head-Holder and Compensation Filter when Calculating Skin Dose during Fluoroscopically-Guided Interventions.

    Vijayan, Sarath; Rana, Vijay K; Rudin, Stephen; Bednarek, Daniel R


    The skin dose tracking system (DTS) that we developed provides a color-coded illustration of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures for immediate feedback to the interventionist. To improve the accuracy of dose calculation, we now have incorporated two additional important corrections (1) for the holder used to immobilize the head in neuro-interventions and (2) for the built-in compensation filters used for beam equalization. Both devices have been modeled in the DTS software so that beam intensity corrections can be made. The head-holder is modeled as two concentric hemi-cylindrical surfaces such that the path length between those surfaces can be determined for rays to individual points on the skin surface. The head-holder on the imaging system we used was measured to attenuate the primary x-rays by 10 to 20% for normal incidence, and up to 40% at non-normal incidence. In addition, three compensation filters of different shape are built into the collimator apparatus and were measured to have attenuation factors ranging from 58% to 99%, depending on kVp and beam filtration. These filters can translate and rotate in the beam and their motion is tracked by the DTS using the digital signal from the imaging system. When it is determined that a ray to a given point on the skin passes through the compensation filter, the appropriate attenuation correction is applied. These corrections have been successfully incorporated in the DTS software to provide a more accurate determination of skin dose.

  11. Shoulder, hip, and knee arthrography needle placement using fluoroscopic guidance: practice patterns of musculoskeletal radiologists in North America

    Shortt, Conor P. [Thomas Jefferson University Hospital, Department of Radiology, Philadelphia, PA (United States); Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Morrison, William B.; Deely, Diane M.; Gopez, Angela G.; Zoga, Adam C. [Thomas Jefferson University Hospital, Department of Radiology, Philadelphia, PA (United States); Roberts, Catherine C. [Mayo Clinic College of Medicine, Department of Radiology, Phoenix, AZ (United States)


    The aim of this study was to evaluate the range of techniques used by radiologists performing shoulder, hip, and knee arthrography using fluoroscopic guidance. Questionnaires on shoulder, hip, and knee arthrography were distributed to radiologists at a national radiology meeting. We enquired regarding years of experience, preferred approaches, needle gauge, gadolinium dilution, and volume injected. For each approach, the radiologist was asked their starting and end needle position based on a numbered and lettered grid superimposed on a radiograph. Sixty-eight questionnaires were returned. Sixty-eight radiologists performed shoulder and hip arthrography, and 65 performed knee arthrograms. Mean experience was 13.5 and 12.8 years, respectively. For magnetic resonance arthrography, a gadolinium dilution of 1/200 was used by 69-71%. For shoulder arthrography, an anterior approach was preferred by 65/68 (96%). The most common site of needle end position, for anterior and posterior approaches, was immediately lateral to the humeral cortex. A 22-gauge needle was used by 46/66 (70%). Mean injected volume was 12.7 ml (5-30). For hip arthrography, an anterior approach was preferred by 51/68 (75%). The most common site of needle end position, for anterior and lateral approaches, was along the lateral femoral head/neck junction. A 22-gauge needle was used by 53/68 (78%). Mean injected volume was 11.5 ml (5-20). For knee arthrography, a lateral approach was preferred by 41/64 (64%). The most common site of needle end position, for lateral and medial approaches, was mid-patellofemoral joint level. A 22-gauge needle was used by 36/65 (56%). Mean injected volume was 28.2 ml (5-60). Arthrographic approaches for the shoulder, hip, and knee vary among radiologists over a wide range of experience levels. (orig.)

  12. Implementation of a competency check-off in diagnostic fluoroscopy for radiology trainees: impact on reducing radiation for three common fluoroscopic exams in children

    Shah, Sweta [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); Desouches, Stephane L. [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); St. Luke' s Hospital, Department of Radiology, Kansas City, MO (United States); Lowe, Lisa H.; Kasraie, Nima; Reading, Brenton [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); Children' s Mercy Hospitals and Clinics, Department of Radiology, Kansas City, MO (United States)


    Fluoroscopy is an important tool for diagnosis in the pediatric population, but it carries the risk of radiation exposure. Because radiology resident education and experience in the use of fluoroscopy equipment in children vary, we implemented an intervention to standardize fluoroscopy training. The purpose of this study is to determine the impact of implementing a fluoroscopy competency check-off for radiology resident trainees aimed at decreasing radiation exposure in three common pediatric fluoroscopic studies. A fluoroscopy competency check-off form was developed for radiology resident trainees performing pediatric procedures. Techniques used to limit radiation exposure for common pediatric radiologic studies were reviewed as part of the check-off process. Pediatric radiologists supervised each trainee until they demonstrated competence to independently perform three specified procedures. Radiation dose was recorded for the three procedures, upper GI (UGI), voiding cystourethrogram (VCUG) and oropharyngeal (OPM) exams, over 6 months preceding and 6 months following implementation of the competency check-off. The mean cumulative dose for each procedure was compared before and after implementation of competency check-off using a Kruskal-Wallis test. During the 12-month study period doses from 909 fluoroscopic procedures were recorded. In the 6 months preceding competency check-off implementation, procedures were performed by 24 radiology resident trainees including 171 UGI, 176 VCUG and 171 OPM exams. In the 6 months following competency check-off, 23 trainees performed 114 UGI, 145 VCUG and 132 OPM exams. After competency check-off implementation, a statistically significant reduction in average radiation dose was found for all three studies (P < 0.001). Median cumulative doses (mGy) were decreased by 33%, 36% and 13% for UGIs, VCUGs and OPMs, respectively. Implementation of a competency check-off for radiology resident trainees can reduce average radiation

  13. SU-E-I-42: Normalized Embryo/fetus Doses for Fluoroscopically Guided Pacemaker Implantation Procedures Calculated Using a Monte Carlo Technique

    Damilakis, J; Stratakis, J; Solomou, G [University of Crete, Heraklion (Greece)


    Purpose: It is well known that pacemaker implantation is sometimes needed in pregnant patients with symptomatic bradycardia. To our knowledge, there is no reported experience regarding radiation doses to the unborn child resulting from fluoroscopy during pacemaker implantation. The purpose of the current study was to develop a method for estimating embryo/fetus dose from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all trimesters of gestation. Methods: The Monte Carlo N-Particle (MCNP) radiation transport code was employed in this study. Three mathematical anthropomorphic phantoms representing the average pregnant patient at the first, second and third trimesters of gestation were generated using Bodybuilder software (White Rock science, White Rock, NM). The normalized embryo/fetus dose from the posteroanterior (PA), the 30° left-anterior oblique (LAO) and the 30° right-anterior oblique (RAO) projections were calculated for a wide range of kVp (50–120 kVp) and total filtration values (2.5–9.0 mm Al). Results: The results consist of radiation doses normalized to a) entrance skin dose (ESD) and b) dose area product (DAP) so that the dose to the unborn child from any fluoroscopic technique and x-ray device used can be calculated. ESD normalized doses ranged from 0.008 (PA, first trimester) to 2.519 μGy/mGy (RAO, third trimester). DAP normalized doses ranged from 0.051 (PA, first trimester) to 12.852 μGy/Gycm2 (RAO, third trimester). Conclusion: Embryo/fetus doses from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all stages of gestation can be estimated using the method developed in this study. This study was supported by the Greek Ministry of Education and Religious Affairs, General Secretariat for Research and Technology, Operational Program ‘Education and Lifelong Learning’, ARISTIA (Research project: CONCERT)

  14. A small-signal approach to temporal modulation transfer functions with exposure-rate dependence and its application to fluoroscopic detective quantum efficiency.

    Friedman, S N; Cunningham, I A


    The detective quantum efficiency (DQE) is a metric widely used in radiography to quantify system performance and as a surrogate measure of patient "dose efficiency." It has been applied previously to fluoroscopic systems with the introduction of a temporal correction factor. Calculation of this correction factor relies on measurements of the temporal modulation transfer function (MTF). However, the temporal MTF is often exposure-rate dependent, violating a necessary Fourier linearity requirement. The authors show that a Fourier analysis is appropriate for fluoroscopic systems if a "small-signal" approach is used. Using a semitransparent edge, a lag-corrected DQE is described and measured for an x-ray image intensifier-based fluoroscopic system under continuous (non-pulsed) exposure conditions. It was found that results were equivalent for both rising and falling-edge profiles independent of edge attenuation when effective attenuation was in the range of 0.1-0.6. This suggests that this range is appropriate for measuring the small-signal temporal MTF. In general, lag was greatest at low exposure rates. It was also found that results obtained using a falling-edge profile with a radiopaque edge were equivalent to the small-signal results for the test system. If this result is found to be true generally, it removes the need for the small-signal approach. Lag-corrected DQE values were validated by comparison with radiographic DQE values obtained using very long exposures under the same conditions. Lag was observed to inflate DQE measurements by up to 50% when ignored.

  15. Diagnostic performance of percutaneous lung biopsy using automated biopsy needles under CT-fluoroscopic guidance for ground-glass opacity lesions

    Yoshimatsu, R; Miura, H; Yamada, K; Takahata, A; Matsumoto, T; Hasebe, T


    Objective: The goal of our study was to evaluate the diagnostic performance of percutaneous lung biopsy under CT-fluoroscopic guidance for ground-glass opacity (GGO) lesions. Methods: 85 percutaneous needle lung biopsies were performed in 73 patients. Specimens were obtained by core biopsy utilising an automated cutting needle and were evaluated histologically. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up. Results: Rates of adequate specimens obtained and of precise diagnosis by needle biopsy were 92.9% (79/85) and 90.6% (77/85) of evaluated lung lesions, respectively. Precise diagnosis was achieved in 87.1% (27/31) of lesions ≤10 mm in diameter, 90.0% (36/40) of lesions >10 mm to ≤20 mm and 100.0% (14/14) of lesions >20 mm. Precision in diagnosing GGO lesions according to the GGO component was 73.9% (17/23) for pure GGO lesions and 96.8% (60/62) for part-solid GGO lesions. Obtaining a precise diagnosis did not differ significantly according to the lesion size (p=0.3840), but differences were significant according to the GGO component (p=0.0047). Malignancy was accurately diagnosed in 35 of 36 malignant lesions for which surgery was later performed. The specific cell type determined from specimens obtained by needle biopsy was exactly the same as the final histological diagnosis obtained after surgery in 20 lesions. Conclusion: Tissue-core lung biopsy under CT-fluoroscopic guidance for a GGO lesion provides a high degree of diagnostic accuracy but is less reliable for determining the specific cell type. Advances in knowledge: Percutaneous lung biopsy under CT-fluoroscopic guidance for GGO is useful in differentiating malignancy. PMID:23385998

  16. In vivo kinematic study of the tarsal joints complex based on fluoroscopic 3D-2D registration technique.

    Chen Wang, M D; Geng, Xiang; Wang, Shaobai; Xin Ma, M D; Xu Wang, M D; Jiazhang Huang, M D; Chao Zhang, M D; Li Chen, M S; Yang, Junsheng; Wang, Kan


    The tarsal bones articulate with each other and demonstrate complicated kinematic characteristics. The in vivo motions of these tarsal joints during normal gait are still unclear. Seven healthy subjects were recruited and fourteen feet in total were tested in the current study. Three dimensional models of the tarsal bones were first created using CT scanning. Corresponding local 3D coordinate systems of each tarsal bone was subsequently established for 6DOF motion decompositions. The fluoroscopy system captured the lateral fluoroscopic images of the targeted tarsal region whilst the subject was walking. Seven key pose images during the stance phase were selected and 3D to 2D bone model registrations were performed on each image to determine joint positions. The 6DOF motions of each tarsal joint during gait were then obtained by connecting these positions together. The TNJ (talo-navicular joint) exhibited the largest ROMs (range of motion) on all rotational directions with 7.39±2.75°of dorsi/plantarflexion, 21.12±4.68°of inversion/eversion, and 16.11±4.44°of internal/external rotation. From heel strike to midstance, the TNJ, STJ (subtalar joint), and CCJ (calcaneao-cuboid joint) were associated with 5.97°, 5.04°, and 3.93°of dorsiflexion; 15.46°, 8.21°, and 5.82°of eversion; and 9.75°, 7.6°, and 4.99°of external rotation, respectively. Likewise, from midstance to heel off, the TNJ, STJ, and CCJ were associated with 6.39, 6.19°, and 4.47°of plantarflexion; 18.57°, 11.86°, and 6.32°of inversion and 13.95°, 9.66°, and 7.58°of internal rotation, respectively. In conclusion, among the tarsal joints, the TNJ exhibited the greatest rotational mobility. Synchronous and homodromous rotational motions were detected for TNJ, STJ, and CCJ during the stance phase.

  17. Risk of whole body radiation exposure and protective measures in fluoroscopically guided interventional techniques: a prospective evaluation

    Rivera Jose


    Full Text Available Abstract Background Fluoroscopic guidance is frequently utilized in interventional pain management. The major purpose of fluoroscopy is correct needle placement to ensure target specificity and accurate delivery of the injectate. Radiation exposure may be associated with risks to physician, patient and personnel. While there have been many studies evaluating the risk of radiation exposure and techniques to reduce this risk in the upper part of the body, the literature is scant in evaluating the risk of radiation exposure in the lower part of the body. Methods Radiation exposure risk to the physician was evaluated in 1156 patients undergoing interventional procedures under fluoroscopy by 3 physicians. Monitoring of scattered radiation exposure in the upper and lower body, inside and outside the lead apron was carried out. Results The average exposure per procedure was 12.0 ± 9.8 seconds, 9.0 ± 0.37 seconds, and 7.5 ± 1.27 seconds in Groups I, II, and III respectively. Scatter radiation exposure ranged from a low of 3.7 ± 0.29 seconds for caudal/interlaminar epidurals to 61.0 ± 9.0 seconds for discography. Inside the apron, over the thyroid collar on the neck, the scatter radiation exposure was 68 mREM in Group I consisting of 201 patients who had a total of 330 procedures with an average of 0.2060 mREM per procedure and 25 mREM in Group II consisting of 446 patients who had a total of 662 procedures with average of 0.0378 mREM per procedure. The scatter radiation exposure was 0 mREM in Group III consisting of 509 patients who had a total 827 procedures. Increased levels of exposures were observed in Groups I and II compared to Group III, and Group I compared to Group II. Groin exposure showed 0 mREM exposure in Groups I and II and 15 mREM in Group III. Scatter radiation exposure for groin outside the apron in Group I was 1260 mREM and per procedure was 3.8182 mREM. In Group II the scatter radiation exposure was 400 mREM and with 0.6042 m

  18. Magnetic Resonance Enterography Findings in Crohn′s disease in the Pediatric Population and Correlation with Fluoroscopic and Multidetector Computed Tomographic Techniques

    Parul Patel


    Full Text Available Traditionally, fluoroscopic examinations such as enteroclysis, upper GI studies, and small bowel follow through exams have been the procedures of choice in evaluating inflammatory bowel disease (IBD in pediatric populations. With the advent of multidetector computed tomography (MDCT, it has subsequently become a complementary examination in imaging inflammatory bowel disease. A major advantage of MDCT over fluoroscopic examination is its ability to directly visualize bowel mucosa, as well as demonstrate extra-enteric complications of IBD such as abscesses, fistulae, and sinus tracts. The major disadvantage of CT however is exposure to ionizing radiation, especially in IBD patients of the pediatric age group who maybe repeatedly imaged due to exacerbations. As a result, magnetic resonance enterography (MRE is becoming increasingly important in the evaluation and follow-up of pediatric patients with IBD. This pictorial essay will summarize the multi-modality imaging findings of IBD with emphasis on MRE including the imaging protocol and procedure. For the purposes of this article, patients less than 17 years of age have been considered to represent the pediatric population.

  19. Fluoroscopically guided caudal epidural steroid injection for management of degenerative lumbar spinal stenosis: short-term and long-term results

    Lee, Joon Woo; Myung, Jae Sung; Kang, Heung Sik [Seoul National University Bundang Hospital, Department of Radiology, Seong Nam, Gyeongi-do (Korea); Park, Kun Woo; Yeom, Jin S. [Seoul National University Bundang Hospital, Department of Orthopaedic Surgery, Seong Nam, Gyeongi-do (Korea); Kim, Ki-Jeong; Kim, Hyun-Jib [Seoul National University Bundang Hospital, Department of Neurosurgery, Seong Nam, Gyeongi-do (Korea)


    To evaluate the short-term and long-term effects of fluoroscopically guided caudal epidural steroid injection (ESI) for the management of degenerative lumbar spinal stenosis (DLSS) and to analyze outcome predictors. All patients who underwent caudal ESI in 2006 for DLSS were included in the study. Response was based on chart documentation (aggravated, no change, slightly improved, much improved, no pain). In June 2009 telephone interviews were conducted, using formatted questions including the North American Spine Society (NASS) patient satisfaction scale. For short-term and long-term effects, age difference was evaluated by the Mann-Whitney U test, and gender, duration of symptoms, level of DLSS, spondylolisthesis, and previous operations were evaluated by Fisher's exact test. Two hundred and sixteen patients (male: female = 75:141; mean age 69.2 years; range 48{proportional_to}91 years) were included in the study. Improvements (slightly improved, much improved, no pain) were seen in 185 patients (85.6%) after an initial caudal ESI and in 189 patients (87.5%) after a series of caudal ESIs. Half of the patients (89/179, 49.8%) replied positively to the NASS patient satisfaction scale (1 or 2). There were no significant outcome predictors for either the short-term or the long-term responses. Fluoroscopically guided caudal ESI was effective for the management of DLSS (especially central canal stenosis) with excellent short-term and good long-term results, without significant outcome predictors. (orig.)

  20. Transcutaneous aortic valve replacement with the Edwards SAPIEN XT and Medtronic CoreValve prosthesis under fluoroscopic guidance and local anaesthesia only.

    Greif, Martin; Lange, Philipp; Näbauer, Michael; Schwarz, Florian; Becker, Christoph; Schmitz, Christoph; Pohl, Tilmann; D'Anastasi, Melvin; Boekstegers, Peter; Massberg, Steffen; Kupatt, Christian


    To assess the feasibility of transcatheter aortic valve implantation (TAVI; Medtronic CoreValve and Edwards SAPIEN XT) under local anaesthesia with only mild analgesic medication and fluoroscopic guidance. 461 patients underwent TAVI under local anaesthesia with lidocaine. The procedure was performed successfully in 459 of the cases. All patients were also treated with piritramide, metoclopramide hydrochloride and 62 mg dimenhydrinate. Monitoring consisted of a six-electrode, virtual 12-lead ECG, pulse oximetry, and invasive arterial pressure measurement. There was no continuous surveillance by an anaesthesiologist. There was no need for conversion to general anaesthesia except in four patients who required cardiopulmonary resuscitation. Conscious sedation with intravenous administration of midazolam for agitation or inotropic medication for prolonged hypotension was necessary in only seven of the 461 patients. The combined safety end point according to the Valve Academic Research Consortium consensus document was reached in 12.6%. Our results show that TAVI performed under local anaesthesia with only mild analgesic medication and under fluoroscopic guidance is feasible, with good outcome comparable to published data.

  1. Feature-based respiratory motion tracking in native fluoroscopic sequences for dynamic roadmaps during minimally invasive procedures in the thorax and abdomen

    Wagner, Martin G.; Laeseke, Paul F.; Schubert, Tilman; Slagowski, Jordan M.; Speidel, Michael A.; Mistretta, Charles A.


    Fluoroscopic image guidance for minimally invasive procedures in the thorax and abdomen suffers from respiratory and cardiac motion, which can cause severe subtraction artifacts and inaccurate image guidance. This work proposes novel techniques for respiratory motion tracking in native fluoroscopic images as well as a model based estimation of vessel deformation. This would allow compensation for respiratory motion during the procedure and therefore simplify the workflow for minimally invasive procedures such as liver embolization. The method first establishes dynamic motion models for both the contrast-enhanced vasculature and curvilinear background features based on a native (non-contrast) and a contrast-enhanced image sequence acquired prior to device manipulation, under free breathing conditions. The model of vascular motion is generated by applying the diffeomorphic demons algorithm to an automatic segmentation of the subtraction sequence. The model of curvilinear background features is based on feature tracking in the native sequence. The two models establish the relationship between the respiratory state, which is inferred from curvilinear background features, and the vascular morphology during that same respiratory state. During subsequent fluoroscopy, curvilinear feature detection is applied to determine the appropriate vessel mask to display. The result is a dynamic motioncompensated vessel mask superimposed on the fluoroscopic image. Quantitative evaluation of the proposed methods was performed using a digital 4D CT-phantom (XCAT), which provides realistic human anatomy including sophisticated respiratory and cardiac motion models. Four groups of datasets were generated, where different parameters (cycle length, maximum diaphragm motion and maximum chest expansion) were modified within each image sequence. Each group contains 4 datasets consisting of the initial native and contrast enhanced sequences as well as a sequence, where the respiratory motion is

  2. An exploration of fluoroscopically guided spinal steroid injections in patients with non-specific exercise-related lower-limb pain

    Leon Neve


    Full Text Available Leon Neve1, John Orchard2, Nathan Gibbs3, Willem van Mechelen4, Evert Verhagen4, Ken Sesel5, Ian Burgess6, Brett Hines61VU University, Amsterdam, The Netherlands; 2School of Public Health, University of Sydney, Sydney, NSW, Australia; 3South Sydney Sports Medicine, Sydney, NSW, Australia; 4EMGO, VU University, Amsterdam, The Netherlands; 5Sydney X-ray Centre, Sydney, NSW, Australia; 6Mater Imaging, Sydney, NSW, AustraliaBackground: Fluoroscopically guided lumbar cortisone injections have been proven useful in cases of lower-limb pain caused by lumbar disc prolapse (with evidence levels ll-1/ll-2. These injections are also sometimes used clinically in sports medicine for patients with non-specific exercise-related lower-limb pain, where no prolapse or other obvious cause of nerve-impingement is diagnosed via magnetic resonance imaging (MRI or computed tomography (CT, even though this treatment scenario has not been adequately studied for this last diagnosis.Objectives: To explore whether fluoroscopically guided transforaminal lumbar cortisone injections may be a valid treatment method for non-specific exercise-related lower-limb pain.Study design: Retrospective case series.Methods: Patients were selected from databases at two sports clinics and divided into two groups: Group D, with back-related lower-limb pain and disc prolapse proven on CT or MR; and Group N, with non-specific exercise-related lower-limb pain. Patients were sent a questionnaire regarding: symptoms, improvement, effect of injections, satisfaction, side effects and other used treatments. Outcomes were compared between Group D and N.Results: 153 patients were eligible for the study (Group D: 93/Group N: 60. Eventually 110 patients responded (Group D: 67/Group N: 43. Twelve percent of Group D and 14% of Group N indicated that the injections had fully cured their symptoms. Altogether, 27% of Group D and 24% of Group N were certain the injections had improved their symptoms in the


    Wrigglesworth, David J; Bailey, Michael Q; Colyer, Alison; Hughes, Kevin R


    A limiting factor of radiographic contrast studies is the requirement for restraint of the animal in order to reduce movement artifacts. To demonstrate that gastrointestinal transit can be analyzed by a barium meal in nonsedated and unrestrained dogs, a pilot study of six adult Labrador retriever dogs was undertaken. Study subjects were selected by convenience sampling from an available population of Labrador dogs and were trained to stand motionless during radiographic fluoroscopy. Following a meal containing 7% w/w powdered barium sulfate, radiographic images were generated using a digital fluoroscope C-arm, at intervals of 5, 15, and 30 min, and at 1, 2, 3, 4, 5, 6, 7, and 8 h. A qualitative assessment of fill density using a 5-point scale was made for the stomach, small intestine, and ascending, transverse, and descending regions of the colon at each timepoint. Gastric emptying half-time occurred between 1 and 2 h postmeal. Mean fill density of the small intestine increased from 15 min postmeal and reached a peak at 3 h postmeal. Mean fill density of the proximal large intestine mirrored that of the small intestine. The distal large intestine remained empty for the first 2 h postmeal, then increased between hours 2 and 5 postmeal, and was subsequently at maximum fill density from hour 6 postmeal onwards. Fluoroscopic observation of a barium contrast meal provided an effective indication of the amount and progression of ingested food through the various regions of the gastrointestinal tract in habituated, fully conscious dogs. © 2016 American College of Veterinary Radiology.

  4. Routine Use of Fluoroscopic-Guided Femoral Arterial Puncture to Minimise Vascular Complication Rates in CTO Intervention: Multi-centre UK Experience.

    Fairley, Sarah L; Lucking, Andrew J; McEntegart, Margaret; Shaukat, Aadil; Smith, David; Chase, Alexander; Hanratty, Colm G; Spratt, James C; Walsh, Simon J


    Chronic total occlusion (CTO) revascularisation has a crucial role in contemporary percutaneous coronary intervention (PCI). Procedural success is influenced by disease complexity, calcific burden and patient characteristics but has substantially improved with the implementation of novel hybrid strategies. However, vascular-access related complications remain a cause of morbidity and mortality. This study aimed to assess the effectiveness of fluoroscopic-guided femoral arterial puncture to minimise this risk during CTO PCI. Standardised data were retrospectively collected from four high-volume UK CTO centres between September 2011 and November 2013. Demographic, clinical and procedural data (vascular access site, sheath size, anticoagulation use) was collated. The anatomical location of the femoral puncture in relation to the femoral bifurcation, femoral head position and inferior epigastric artery were recorded. Adverse events related to vascular access were documented. A total of 528 patients were included (676 femoral punctures) with the majority being male (n=432, 81.8%). Large sheaths (8F) were used in 81.2% of cases. Fluoroscopy-enabled punctures were made in the 'safe zone' in over > 93% of cases. Vascular closure devices (VCD) were used in 88.3% of cases. The adverse event rate per puncture was 0.89%. This study demonstrates an extremely low incidence of vascular-access complications in CTO PCI when fluoroscopic guidance is used to obtain femoral arterial access by default radial operators. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  5. Integration of kerma-area product and cumulative air kerma determination into a skin dose tracking system for fluoroscopic imaging procedures

    Vijayan, Sarath; Shankar, Alok; Rudin, Stephen; Bednarek, Daniel R.


    The skin dose tracking system (DTS) that we developed provides a color-coded mapping of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures in real time. The DTS has now been modified to also calculate the kerma area product (KAP) and cumulative air kerma (CAK) for fluoroscopic interventions using data obtained in real-time from the digital bus on a Toshiba Infinix system. KAP is the integral of air kerma over the beam area and is typically measured with a large-area transmission ionization chamber incorporated into the collimator assembly. In this software, KAP is automatically determined for each x-ray pulse as the product of the air kerma/ mAs from a calibration file for the given kVp and beam filtration times the mAs per pulse times the length and width of the beam times a field nonuniformity correction factor. Field nonuniformity is primarily the result of the heel effect and the correction factor was determined from the beam profile measured using radio-chromic film. Dividing the KAP by the beam area at the interventional reference point provides the area averaged CAK. The KAP and CAK per x-ray pulse are summed after each pulse to obtain the total procedure values in real-time. The calculated KAP and CAK were compared to the values displayed by the fluoroscopy machine with excellent agreement. The DTS now is able to automatically calculate both KAP and CAK without the need for measurement by an add-on transmission ionization chamber.

  6. Radiation dose and intra-articular access: comparison of the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections

    Huang, Ambrose J.; Torriani, Martin; Bredella, Miriam A.; Chang, Connie Y.; Simeone, Frank J.; Palmer, William E. [Massachusetts General Hospital, Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Boston, MA (United States); Balza, Rene [Centro Medico de Occidente, Department of Radiology, Maracaibo (Venezuela, Bolivarian Republic of)


    To compare the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections with respect to successful intra-articular needle placement, fluoroscopy time, radiation dose, and dose area product (DAP). This retrospective study was IRB-approved and HIPAA-compliant. 498 fluoroscopically guided tibiotalar joint injections were performed or supervised by one of nine staff radiologists from 11/1/2010-12/31/2013. The injection approach was determined by operator preference. Images were reviewed on a PACS workstation to determine the injection approach (lateral mortise versus anterior midline) and to confirm intra-articular needle placement. Fluoroscopy time (minutes), radiation dose (mGy), and DAP (μGy-m{sup 2}) were recorded and compared using the student's t-test (fluoroscopy time) or the Wilcoxon rank sum test (radiation dose and DAP). There were 246 lateral mortise injections and 252 anterior midline injections. Two lateral mortise injections were excluded from further analysis because no contrast was administered. Intra-articular location of the needle tip was documented in 242/244 lateral mortise injections and 252/252 anterior midline injections. Mean fluoroscopy time was shorter for the lateral mortise group than the anterior midline group (0.7 ± 0.5 min versus 1.2 ± 0.8 min, P < 0.0001). Mean radiation dose and DAP were less for the lateral mortise group than the anterior midline group (2.1 ± 3.7 mGy versus 2.5 ± 3.5 mGy, P = 0.04; 11.5 ± 15.3 μGy-m{sup 2} versus 13.5 ± 17.3 μGy-m{sup 2}, P = 0.006). Both injection approaches resulted in nearly 100 % rates of intra-articular needle placement, but the lateral mortise approach used approximately 40 % less fluoroscopy time and delivered 15 % lower radiation dose and DAP to the patient. (orig.)

  7. Dose reduction in fluoroscopic interventions using a combination of a region of interest (ROI) x-ray attenuator and spatially different, temporally variable temporal filtering

    Swetadri Vasan, S. N.; Pope, Liza; Ionita, Ciprian N.; Titus, A. H.; Bednarek, D. R.; Rudin, S.


    A novel dose reduction technique for fluoroscopic interventions involving a combination of a material x-ray region of interest (ROI) attenuator and spatially different, temporally variable ROI temporal recursive filter, was used to guide the catheter to the ROI in three live animal studies, two involving rabbits and one involving a sheep. In the two rabbit studies presented , a catheter was guided to the entrance of the carotid artery. With the added ROI attenuator the image under the high attenuation region is very noisy. By using temporal filtering with a filter weight of 0.6 on previous frames, the noise is reduced. In the sheep study the catheter was guided to the descending aorta of the animal. The sheep offered a relatively higher attenuation to the incident x-rays and thus a higher temporal filter weight of 0.8 on previous frames was used during the procedure to reduce the noise to levels acceptable by the interventionalist. The image sequences from both studies show that significant dose reduction of 5-6 times can be achieved with acceptable image quality outside the ROI by using the above mentioned technique. Even though the temporal filter weighting outside the ROI is higher, the consequent lag does not prevent perception of catheter movement.

  8. Direct percutaneous transorbital puncture under fluoroscopic guidance with a 3D skull reconstruction overlay for embolisation of intraorbital and cavernous sinus dural arteriovenous fistulas.

    Lv, Ming; Jiang, Chuhan; Liu, Dong; Ning, Zhiguang; Yang, Jun; Wu, Zhongxue


    To describe the direct percutaneous transorbital puncture technique for embolisation of the selected intraorbital and cavernous sinus dural arteriovenous fistula, which failed to be treated by conventional endovascular techniques. One case of intraorbital and five cases of cavernous sinus dural arteriovenous fistula were embolised through direct percutaneous transorbital puncture in 2012, and the clinical data were reviewed. Under fluoroscopic guidance with a three-dimensional (3D) skull reconstruction overlay, the cavernous sinus or ophthalmic vein was punctured via the superior orbital fissure. Then a microcatheter was inserted via the needle, and Onyx was injected to embolise the fistula with or without a combination of coils. Complete obliteration of the fistula was achieved in all six patients. After operation all the patients experienced transient swelling of the punctured orbit persisting for three to five days. No other complications occurred. Follow-up of six patients at three to six months showed resolution of their initial neuro-ophthalmological symptoms in five and left visual loss in one did not recover. Six months follow-up angiogram showed no recurrence of these fistulas. Direct percutaneous transorbital puncture provides an option for the intraorbital and cavernous sinus dural arteriovenous fistulas, particularly when the conventional transvenous routes are inaccessible. Overlay of the 3D skull reconstruction can facilitate the precise puncture of the superior orbital fissure. © The Author(s) 2015.


    Bhavani Prasad


    Full Text Available BACKGROUND AND INTRODUCTION: Management of tibial plateau fractures had witnessed tremendous improvement in surgical techniques over the past decades. Conservative treatment of these fractures results in consistently poor results. The present literature supports that absolute anatomi cal reduction and stable fixation of peri articular fractures followed by early post - operative rehabilitation is crucial for good results. And if this is achieved by minimal damage to soft tissue the results are much better. In this study it is achieved by arthroscopy and fluoroscopy. MATERIALS AND METHODS: We have conducted a prospective study between September 2009 to august 2013 including 9 patients with tibial plateau fractures treated with combined arthroscopic and fluoroscopic reduction and internal f ixation with or without bone grafting. And then the radiographic and functional evaluation done. RESULTS: According to Hohl’s clinical and radiographic scoring systems 4 patients were assessed excellent, 3 good, 2 fair. According to Rasmussen’s clinical sc oring system 4 patients excellent, 3 good and 2 fair results. CONCLUSION: The use of arthroscopy and fluoroscopy in the management of tibial plateau fractures results in good outcome. It also helped to simultaneously treat the meniscal injuries. But its use is mainly limited to Shatzkar type1, 2, 3, 4

  10. Systematic investigation of the signal properties of polycrystalline HgI{sub 2} detectors under mammographic, radiographic, fluoroscopic and radiotherapy irradiation conditions

    Su Zhong; Antonuk, Larry E; El-Mohri, Youcef; Hu, Larry; Du Hong; Sawant, Amit; Li Yixin; Wang Yi; Yamamoto, Jin; Zhao Qihua [Department of Radiation Oncology, University of Michigan, 519 W. William St., Argus Building 1, Ann Arbor, MI 48103-4943 (United States)


    The signal properties of polycrystalline mercuric iodide (HgI{sub 2}) film detectors, under irradiation conditions relevant to mammographic, radiographic, fluoroscopic and radiotherapy x-ray imaging, are reported. Each film detector consists of an {approx}230 to {approx}460 {mu}m thick layer of HgI{sub 2} (fabricated through physical vapour deposition or a screen-print process) and a thin barrier layer, sandwiched between a pair of opposing electrode plates. The high atomic number, high density and low effective ionization energy, W{sub EFF}, of HgI{sub 2} make it an attractive candidate for significantly improving the performance of active matrix, flat-panel imagers (AMFPIs) for several x-ray imaging applications. The temporal behaviour of current from the film detectors in the presence and in the absence of radiation was used to examine dark current levels, the lag and reciprocity of the signal response, x-ray sensitivity and W{sub EFF}. The results are discussed in the context of present AMFPI performance. This study provides performance data for a wide range of potential medical x-ray imaging applications from a single set of detectors and represents the first investigation of the signal properties of polycrystalline mercuric iodide for the radiotherapy application.

  11. The performance of a NERO 8000 non-invasive x-ray beam analyser when measuring tube voltage under fluoroscopic conditions.

    Burrage, J W


    A NERO 8000 non-invasive x-ray beam analyser was examined under fluoroscopic conditions with respect to the measurement of tube voltage. An invasive measurement of tube voltage was performed concurrently to test the accuracy of the NERO device over a range of tube voltages and currents. The data indicated that for the NERO 8000 the accuracy of kVp average measurement is dependent on input doserate. With the tube current set to 1 mA the doserates ranged from 2.1 to 6.5 mGy/min over the range of tube voltages measured. The associated kVp average measurement errors ranged from 6 to 28%. At 5 mA the doserates ranged from 20.4 to 66.0 mGy/min and the associated errors ranged from 0 to 3%. A possible explanation for the drop in accuracy of kVp measurements at low doserates is a decreased signal to noise ratio. The kV waveforms from inaccurate measurements appeared noisier than waveforms from more accurate measurements. NERO may be interpreting noise spikes as voltage readings and including them in the kVp average calculations, causing an erroneously high kVp average reading. The data from this experiment suggest that when performing non-invasive measurements of tube voltage accuracy in fluoroscopy mode, the doserate must be taken into consideration.

  12. WE-G-207-06: 3D Fluoroscopic Image Generation From Patient-Specific 4DCBCT-Based Motion Models Derived From Physical Phantom and Clinical Patient Images

    Dhou, S; Cai, W; Hurwitz, M; Rottmann, J; Myronakis, M; Cifter, F; Berbeco, R; Lewis, J [Brigham and Women’s Hospital, Boston, MA (United States); Williams, C [Harvard Medical School, Cambridge, MA (United States); Mishra, P [Varian Medical Systems, Palo Alto, CA (United States); Ionascu, D [William Beaumont Hospital, Royal Oak, MI (United States)


    Purpose: Respiratory-correlated cone-beam CT (4DCBCT) images acquired immediately prior to treatment have the potential to represent patient motion patterns and anatomy during treatment, including both intra- and inter-fractional changes. We develop a method to generate patient-specific motion models based on 4DCBCT images acquired with existing clinical equipment and used to generate time varying volumetric images (3D fluoroscopic images) representing motion during treatment delivery. Methods: Motion models are derived by deformably registering each 4DCBCT phase to a reference phase, and performing principal component analysis (PCA) on the resulting displacement vector fields. 3D fluoroscopic images are estimated by optimizing the resulting PCA coefficients iteratively through comparison of the cone-beam projections simulating kV treatment imaging and digitally reconstructed radiographs generated from the motion model. Patient and physical phantom datasets are used to evaluate the method in terms of tumor localization error compared to manually defined ground truth positions. Results: 4DCBCT-based motion models were derived and used to generate 3D fluoroscopic images at treatment time. For the patient datasets, the average tumor localization error and the 95th percentile were 1.57 and 3.13 respectively in subsets of four patient datasets. For the physical phantom datasets, the average tumor localization error and the 95th percentile were 1.14 and 2.78 respectively in two datasets. 4DCBCT motion models are shown to perform well in the context of generating 3D fluoroscopic images due to their ability to reproduce anatomical changes at treatment time. Conclusion: This study showed the feasibility of deriving 4DCBCT-based motion models and using them to generate 3D fluoroscopic images at treatment time in real clinical settings. 4DCBCT-based motion models were found to account for the 3D non-rigid motion of the patient anatomy during treatment and have the potential

  13. LabVIEW Graphical User Interface for a New High Sensitivity, High Resolution Micro-Angio-Fluoroscopic and ROI-CBCT System.

    Keleshis, C; Ionita, Cn; Yadava, G; Patel, V; Bednarek, Dr; Hoffmann, Kr; Verevkin, A; Rudin, S


    A graphical user interface based on LabVIEW software was developed to enable clinical evaluation of a new High-Sensitivity Micro-Angio-Fluoroscopic (HSMAF) system for real-time acquisition, display and rapid frame transfer of high-resolution region-of-interest images. The HSMAF detector consists of a CsI(Tl) phosphor, a light image intensifier (LII), and a fiber-optic taper coupled to a progressive scan, frame-transfer, charged-coupled device (CCD) camera which provides real-time 12 bit, 1k × 1k images capable of greater than 10 lp/mm resolution. Images can be captured in continuous or triggered mode, and the camera can be programmed by a computer using Camera Link serial communication. A graphical user interface was developed to control the camera modes such as gain and pixel binning as well as to acquire, store, display, and process the images. The program, written in LabVIEW, has the following capabilities: camera initialization, synchronized image acquisition with the x-ray pulses, roadmap and digital subtraction angiography acquisition (DSA), flat field correction, brightness and contrast control, last frame hold in fluoroscopy, looped playback of the acquired images in angiography, recursive temporal filtering and LII gain control. Frame rates can be up to 30 fps in full-resolution mode. The user friendly implementation of the interface along with the high framerate acquisition and display for this unique high-resolution detector should provide angiographers and interventionalists with a new capability for visualizing details of small vessels and endovascular devices such as stents and hence enable more accurate diagnoses and image guided interventions. (Support: NIH Grants R01NS43924, R01EB002873).

  14. Fluoroscopic-guided primary single-step percutaneous gastrostomy. Initial results using the Freka {sup registered} GastroTube; Primaere einzeitige durchleuchtungsgesteuerte perkutane Gastrostomie (PG). Erste Ergebnisse mit dem Freka {sup registered} GastroTube

    Hahne, J.D.; Schoennagel, B.P.; Arndt, C.; Bannas, P.; Koops, A.; Adam, G.; Habermann, C.R. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Zentrum fuer Radiologie; Herrmann, J. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Zentrum fuer Radiologie; Universitaetsklinikum Hamburg-Eppendorf (Germany). Abt. Paediatrische Radiologie


    Purpose: To determine the practicability and outcome of fluoroscopic-guided primary one-step treatment of percutaneous gastrostomy (PG) with the system Freka {sup registered} Gastro Tube (Fresenius Kabi, Germany). Materials and Methods: In 39 patients (mean age 62.7 {+-} 12.0 years), primary PG was performed based on clinical indication from August 2009 to April 2010. The intervention was performed by an experienced radiologist under aseptic conditions by direct puncture with Freka {sup registered} Gastro Tube under fluoroscopic guidance. The clinical data and outcome as well as any complications originated from the electronic archive of the University Medical Center Hamburg-Eppendorf. Results: The intervention was technically successful in all 39 patients. Within the mean follow-up time of 155.3 {+-} 73.6 days, 29 patients (74.4 %) did not experience complications. 10 patients (25.6 %) had to be revised. Complications manifested after a mean of 135.6 {+-} 61.2 days and mainly corresponded to accidental dislocation (50 %). One patient had to be surgically revised under suspicion of a malpositioned tube and suspected intestinal perforation. Clinically relevant wound infections were not detected. The total costs per patient were 553.17 Euro for our single-step treatment (OPS 5 - 431.x) vs. 963.69 Euro (OPS 5 - 431.x and OPS 8 - 123.0) for the recommended two-step treatment. Conclusion: Fluoroscopic-guided primary single-step treatment with Freka {sup registered} Gastro Tube system is feasible and not associated with an increased complication rate when compared to published literature applying a two-step treatment approach. Material costs as well as human and time resources could be significantly reduced using the single-step treatment. (orig.)

  15. Comparison of conventional full spine radiographs and fluoroscopic scanning method in young patients with idiopathic scoliosis; Vergleich von konventioneller Wirbelsaeulenganzaufnahme und fluoroskopischer Scan-Methode bei jungen Patienten mit idiopathischer Skoliose

    Schaefer, J.; Kottke, R.; Claussen, C. [Abt. fuer Radiologische Diagnostik, Universitaetsklinikum Tuebingen (Germany); Kluba, T.; Niemeyer, T.; Hahnfeldt, T. [Klinik und Poliklinik fuer Orthopaedie, Universitaetsklinikum Tuebingen (Germany); Vonthein, R. [Inst. fuer Medizinische Biometrie, Universitaetsklinikum Tuebingen (Germany); Kamm, K.F. [Philips Medizin Systeme GmbH, Hamburg (Germany)


    Purpose: evaluation of low-dose full spine radiographs using fluoroscopic images for the assessment of the Cobb angle measurement in patients with scoliosis. Material and methods: twenty-one consecutive patients (aged 10-27 years, mean age 14 years) with a conventional full spine examination (film speed class 800) underwent a follow-up exam using digital pulsed fluoroscopy (Multi Diagnost 4, Philips Medical Systems, Eindhoven, The Netherlands). The mean follow-up was 9 months. During a synchronized scan with a C-arm speed of 4 cm/sec fluoroscopic images were stored with a pulsed frequency of 3 images per second. The single images were merged and reconstructed to one image with the software easy spine (Philips medical Systems, Eindhoven, The Netherlands). The corresponding dose-area product values (DAP) of both methods were compared. Three independent observers assessed Cobb angles and image quality for each technique. Results: the mean DAP values for conventional imaging was 94.9 cGy x cm{sup 2} and for fluoroscopy 7.8 cGy x cm{sup 2}, respectively. A significant dose reduction of 91.8% (CI 91% to 95%) was calculated. The average absolute angle difference between the observers was found to be 2.7 for conventional imaging and 2.4 for the fluoroscopic method. Interobserver standard deviation of 2.9 was lower than the 5.3 for conventional images. Image quality was better in the conventional images. Conclusion: using the scanning method, we could achieve a mean reduction of the radiation dose of 92%, while the accuracy of the Cobb angle measurements was comparable for both techniques despite of reduced image quality of digital fluoroscopy. (orig.)

  16. A theoretical and experimental evaluation of the microangiographic fluoroscope: A high-resolution region-of-interest x-ray imager

    Jain, Amit; Bednarek, D. R.; Ionita, Ciprian; Rudin, S. [Toshiba Stroke Research Center, University at Buffalo, State University of New York, Buffalo, New York 14214 (United States); Department of Radiology, Department of Neurosurgery, Department of Physiology and Biophysics, Toshiba Stroke Research Center, University at Buffalo, State University of New York, Buffalo, New York 14214 (United States); Department of Neurosurgery, Toshiba Stroke Research Center, University at Buffalo, State University of New York, Buffalo, New York 14214 (United States); Department of Radiology, Department of Neurosurgery, Department of Physiology and Biophysics, Department of Mechanical and Aerospace Engineering, Department of Electrical Engineering, Department of Biomedical Engineering, Toshiba Stroke Research Center, University at Buffalo, State University of New York, Buffalo, New York 14214 (United States)


    Purpose: The increasing need for better image quality and high spatial resolution for successful endovascular image-guided interventions (EIGIs) and the inherent limitations of the state-of-the-art detectors provide motivation to develop a detector system tailored to the specific, demanding requirements of neurointerventional applications.Method: A microangiographic fluoroscope (MAF) was developed to serve as a high-resolution, region-of-interest (ROI) x-ray imaging detector in conjunction with large lower-resolution full field-of-view (FOV) state-of-the-art x-ray detectors. The newly developed MAF is an indirect x-ray imaging detector capable of providing real-time images (30 frames per second) with high-resolution, high sensitivity, no lag and low instrumentation noise. It consists of a CCD camera coupled to a Gen 2 dual-stage microchannel plate light image intensifier (LII) through a fiber-optic taper. A 300 {mu}m thick CsI(Tl) phosphor serving as the front end is coupled to the LII. The LII is the key component of the MAF and the large variable gain provided by it enables the MAF to operate as a quantum-noise-limited detector for both fluoroscopy and angiography. Results: The linear cascade model was used to predict the theoretical performance of the MAF, and the theoretical prediction showed close agreement with experimental findings. Linear system metrics such as MTF and DQE were used to gauge the detector performance up to 10 cycles/mm. The measured zero frequency DQE(0) was 0.55 for an RQA5 spectrum. A total of 21 stages were identified for the whole imaging chain and each stage was characterized individually. Conclusions: The linear cascade model analysis provides insight into the imaging chain and may be useful for further development of the MAF detector. The preclinical testing of the prototype detector in animal procedures is showing encouraging results and points to the potential for significant impact on EIGIs when used in conjunction with a state

  17. SU-E-I-22: Dependence On Calibration Phantom and Field Area of the Conversion Factor Used to Calculate Skin Dose During Neuro-Interventional Fluoroscopic Procedures

    Rana, V K; Vijayan, S [Physiology and Biophysics, Toshiba Stroke and Vascular Research Center, University at Buffalo (State University of New York), Buffalo, NY (United States); Rudin, S R; Bednarek, D R [Department of Radiology, Physiology and Biophysics, Toshiba Stroke and Vascular Research Center, University at Buffalo (State University of New York), Buffalo, NY (United States)


    Purpose: To determine the appropriate calibration factor to use when calculating skin dose with our real-time dose-tracking system (DTS) during neuro-interventional fluoroscopic procedures by evaluating the difference in backscatter from different phantoms and as a function of entrance-skin field area. Methods: We developed a dose-tracking system to calculate and graphically display the cumulative skin-dose distribution in real time. To calibrate the DTS for neuro-interventional procedures, a phantom is needed that closely approximates the scattering properties of the head. We compared the x-ray backscatter from eight phantoms: 20-cm-thick solid water, 16-cm diameter water-filled container, 16-cm CTDI phantom, modified-ANSI head phantom, 20-cm-thick PMMA, Kyoto-Kagaku PBU- 50 head, Phantom-Labs SK-150 head, and RSD RS-240T head. The phantoms were placed on the patient table with the entrance surface at 15 cm tube-side from the isocenter of a Toshiba Infinix C-arm, and the entrance-skin exposure was measured with a calibrated 6-cc PTW ionization chamber. The measurement included primary radiation, backscatter from the phantom and forward scatter from the table and pad. The variation in entrance-skin exposure was also measured as a function of the skin-entrance area for a 30x30 cm by 20-cm-thick PMMA phantom and the SK-150 head phantom using four different added beam filters. Results: The entranceskin exposure values measured for eight different phantoms differed by up to 12%, while the ratio of entrance exposure of all phantoms relative to solid water showed less than 3% variation with kVp. The change in entrance-skin exposure with entrance-skin area was found to differ for the SK-150 head compared to the 20-cm PMMA phantom and the variation with field area was dependent on the added beam filtration. Conclusion: To accurately calculate skin dose for neuro-interventional procedures with the DTS, the phantom for calibration should be carefully chosen since different

  18. SU-C-210-04: Considerable Pancreatic Tumor Motion During Breath-Hold Measured Using Intratumoral Fiducials On Fluoroscopic Movies

    Lens, E; Horst, A van der; Versteijne, E; Tienhoven, G van; Bel, A [Academic Medical Center, Amsterdam (Netherlands)


    Purpose: Using a breath hold (BH) technique during radiotherapy of pancreatic tumors is expected to reduce intra-fractional motion. The aim of this study was to evaluate the tumor motion during BH. Methods: In this pilot study, we included 8 consecutive pancreatic cancer patients. All had 2– 4 intratumoral gold fiducials. Patients were asked to perform 3 consecutive 30-second end-inhale BHs on day 5, 10 and 15 of their three-week treatment. During BH, airflow through a mouthpiece was measured using a spirometer. Any inadvertent flow of air during BH was monitored for all patients. We measured tumor motion on lateral fluoroscopic movies (57 in total) made during BH. In each movie the fiducials as a group were tracked over time in superior-inferior (SI) and anterior-posterior (AP) direction using 2-D image correlation between consecutive frames. We determined for each patient the range of intra-BH motion over all movies; we also determined the absolute means and standard deviations (SDs) for the entire patient group. Additionally, we investigated the relation between inadvertent airflow during BH and the intra-BH motion. Results: We found intra-BH tumor motion of up to 12.5 mm (range, 1.0–12.5 mm) in SI direction and up to 8.0 mm (range, 1.0–8.0 mm) in AP direction. The absolute mean motion over the patient population was 4.7 (SD: 3.0) mm and 2.8 (SD: 1.2) mm in the SI and AP direction, respectively. Patients were able to perform stable consecutive BHs; during only 20% of the movies we found very small airflows (≤ 65 ml). These were mostly stepwise in nature and could not explain the continuous tumor motions we observed. Conclusion: We found substantial (up to 12.5 mm) pancreatic tumor motion during BHs. We found minimal inadvertent airflow, seen only during a minority of BHs, and this did not explain the obtained results. This work was supported by the foundation Bergh in het Zadel through the Dutch Cancer Society (KWF Kankerbestrijding) project No. UVA 2011-5271.

  19. Prosthesis alignment affects axial rotation motion after total knee replacement: a prospective in vivo study combining computed tomography and fluoroscopic evaluations

    Harman Melinda K


    Full Text Available Abstract Background Clinical consequences of alignment errors in total knee replacement (TKR have led to the rigorous evaluation of surgical alignment techniques. Rotational alignment in the transverse plane has proven particularly problematic, with errors due to component malalignment relative to bone anatomic landmarks and an overall mismatch between the femoral and tibial components’ relative positions. Ranges of nominal rotational alignment are not well defined, especially for the tibial component and for relative rotational mismatch, and some studies advocate the use of mobile-bearing TKR to accommodate the resulting small rotation errors. However, the relationships between prosthesis rotational alignment and mobile-bearing polyethylene insert motion are poorly understood. This prospective, in vivo study evaluates whether component malalignment and mismatch affect axial rotation motions during passive knee flexion after TKR. Methods Eighty patients were implanted with mobile-bearing TKR. Rotational alignment of the femoral and tibial components was measured from postoperative CT scans. All TKR were categorized into nominal or outlier groups based on defined norms for surgical rotational alignment relative to bone anatomic landmarks and relative rotational mismatch between the femoral and tibial components. Axial rotation motion of the femoral, tibial and polyethylene bearing components was measured from fluoroscopic images acquired during passive knee flexion. Results Axial rotation motion was generally accomplished in two phases, dominated by polyethylene bearing rotation on the tibial component in early to mid-flexion and then femoral component rotation on the polyethylene articular surface in later flexion. Opposite rotations of the femur-bearing and bearing-baseplate articulations were evident at flexion greater than 80°. Knees with outlier alignment had lower magnitudes of axial rotation and distinct transitions from external to

  20. Measurements of the modulation transfer function, normalized noise power spectrum and detective quantum efficiency for two flat panel detectors: a fluoroscopic and a cone beam computer tomography flat panel detectors.

    Benítez, Ricardo Betancourt; Ning, Ruola; Conover, David; Liu, Shaohua


    The physical performance of two Flat Panel Detectors has been evaluated. The first Flat Panel Detector is for Fluoroscopic applications, Varian PaxScan 2520, and the second is for Cone Beam Computer Tomography applications, Varian PaxScan 4030CB. First, the spectrum of the X-ray source was measured. Second, the linearity of the detectors was investigated by using an ionization chamber and the average ADU values of the detectors. Third, the temporal resolution was characterized by evaluating their image lag. Fourth, their spatial resolution was characterized by the pre-sampling Modulation Transfer Function. Fifth, the Normalized Noise Power Spectrum was calculated for various exposures levels. Finally, the Detective Quantum Efficiency was obtained as a function of spatial frequency and entrance exposure. The results illustrate that the physical performance in Detective Quantum Efficiency and Normalized Noise Power Spectrum of the Cone Beam Computer Tomography detector is superior to that of the fluoroscopic detector whereas the latter detector has a higher spatial resolution as demonstrated by larger values of its Modulation Transfer Function at large spatial frequencies.

  1. Preliminary trial of identification of brain structures in nude mice with green fluorescent protein expression by fluoroscope%荧光镜下界定绿色荧光裸小鼠脑结构部位

    郑达理; 董军; 兰青; 黄强; 钱志远; 李如军; 王爱东; 崔宝乾; 陈延明; 费喜峰; 吴明霞; 霍红梅


    目的 探讨荧光镜下界定绿色荧光裸小鼠脑结构部位的可行性及优势所在.方法 取表达绿色荧光蛋白(GFP)的成年裸小鼠脑置于SLY脑切片模具中,切出1mm或0.9 mm厚的脑片,再分别对其进行25 μm厚的冰冻切片.荧光镜下观察切片的形态结构,结合《小鼠脑立体定位图谱》中小鼠脑解剖资料,在荧光镜下界定其解剖结构.观察结束后,全部切片行尼氏染色做对照.结果 依据脑内不同结构间的荧光色差可对其进行辨认:细胞核、尼氏小体密集区及神经束分布区为弱荧光信号;细胞核、尼氏小体密集区周围结构,如嗅球的丛状层、小脑的分子层为强荧光信号.切片经尼氏染色后,体视显微镜下观察到的脑结构与荧光镜观察的结果基本一致. 结论 荧光镜下界定绿色荧光裸小鼠脑结构部位可作为一个实验手段应用于荧光示踪实验的解剖定位研究.%Objective To explore the feasibility and advantage of fluoroscope in identification of brain structures in nude mice with green fluorescent protein (GFP) expression. Methods We laid the whole brain separated from 8-week adult nude mice with GFP expression into SLY mouse brain blocker to produce slices of 1 or 0.9 mm thickness; and then,25 μm-thickness frozen sections were cut.Fluoroscope was employed to observe the morphological structure to define their anatomic structures with reference to The Mouse Brain in Stereotaxic Coordinates compiled by Paxinos. After the observation,these frozen sections were performed Nissi staining for contrast. Results Different structures can be identified by their distinct fluorescence intensity:the dense areas of nuclei,Nissl bodies and nerve tract showed low fluorescence intensity; while the structures around the areas of nuclei and nerve tract,such as,the plexiform layer of olfactory bulb and the molecular layer of cerebella,showed high fluorescence intensity.The fluorescence intensity was

  2. Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: a report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council.

    Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith


    Task Group 125 (TG 125) was charged with investigating the functionality of fluoroscopic automatic dose rate and image quality control logic in modern angiographic systems, paying specific attention to the spectral shaping filters and variations in the selected radiologic imaging parameters. The task group was also charged with describing the operational aspects of the imaging equipment for the purpose of assisting the clinical medical physicist with clinical set-up and performance evaluation. Although there are clear distinctions between the fluoroscopic operation of an angiographic system and its acquisition modes (digital cine, digital angiography, digital subtraction angiography, etc.), the scope of this work was limited to the fluoroscopic operation of the systems studied. The use of spectral shaping filters in cardiovascular and interventional angiography equipment has been shown to reduce patient dose. If the imaging control algorithm were programmed to work in conjunction with the selected spectral filter, and if the generator parameters were optimized for the selected filter, then image quality could also be improved. Although assessment of image quality was not included as part of this report, it was recognized that for fluoroscopic imaging the parameters that influence radiation output, differential absorption, and patient dose are also the same parameters that influence image quality. Therefore, this report will utilize the terminology "automatic dose rate and image quality" (ADRIQ) when describing the control logic in modern interventional angiographic systems and, where relevant, will describe the influence of controlled parameters on the subsequent image quality. A total of 22 angiography units were investigated by the task group and of these one each was chosen as representative of the equipment manufactured by GE Healthcare, Philips Medical Systems, Shimadzu Medical USA, and Siemens Medical Systems. All equipment, for which measurement data were

  3. Análise fluoroscópica da movimentação in vivo do insert na ATJ de plataforma rotatória Fluoroscopic analysis of in vivo movement of the insert in rotating platform TKA

    Carlos Eduardo Gonçales Barsotti


    Full Text Available OBJETIVO: Confirmar por análise fluoroscópica a movimentação rotacional do insert de polietileno em artroplastias totais de joelho (ATJ de plataforma rotatória, após um tempo pós operatório mínimo de seis meses, foram estudados 15 joelhos, submetidos a ATJ de plataforma rotatória, com a prótese NEW WAVE, da LEPINE. MÉTODOS: Foi utilizado para a avaliação da rotação do insert de polietileno através de um aparelho de fluoroscopia numa visão anteroposterior do joelho com 90º de flexão. Caso a imagem do marcador radiopaco do polietileno permanecesse inalterada, ou seja, acompanhasse o fêmur, era considerado então que a rotação estaria ocorrendo entre o insert e o componente tibial. RESULTADOS: Dos 15 joelhos analisados, 14 apresentaram movimentação demonstrável do insert de polietileno, totalizando 93,3%. Para que a ATJ de plataforma rotatória mantenha seu potencial é necessário que a movimentação rotacional do insert de polietileno se mantenha com o tempo. CONCLUSÃO: Com estudo dessa amostra concluiu-se que a rotação se mantém de forma consistente (93%. Sugerindo que a ATJ de plataforma rotatória tem efetivamente o potencial de apresentar menor desgaste do polietileno pela maior congruência articular, em relação à ATJ de apoio fixo, além da vantagem de auto-alinhamento do mecanismo extensor.OBJECTIVE: To confirm by fluoroscopic analysis the rotational movement of the polyethylene insert in rotating platform total knee arthroplasty (TKA after a minimum postoperative time of six months. Fifteen knees submitted to rotating platform TKA with the LEPINE NEW WAVE prosthesis were studied. METHODS: A fluoroscopic appliance in an anterior-posterior view of the proximal tibia was used to evaluate the rotation of the polyethylene insert, with the knee at a 90º flexion. If the image of the polyethylene radiopaque marker remained unchanged, i.e. if it accompanied the femur, then it was considered that rotation was

  4. Fluoroscopically-guided transforaminal epidural steroid injection for the treatment of sciatica due to herniated nucleus pulposus%X线引导经椎间孔硬膜外注射治疗坐骨神经痛

    刘潇; 王建辉; 段早辉; 徐志涛; 舒晓敏; 邱荣华


    Objective To discuss the therapeutic benefit of fluoroscopically-guided lumbar transforaminal epidural steroid injections (TFESI) in treating patients with sciatica due to a herniated nucleus pulposus. Methods From October 2004 to November 2007, fluomscopically-guided lumbar TFESI as performed in 79 patients (41 males and 38 females with a mean age of 45.75 years, ranged from 20 to 70 years) with sciatica due to a herniated nucleus pulposus. Patients had a symptomatic course of disease from 8 weeks to 22 years and showed no response to conservative treatment. The diagnosis was confirmed by computed tomography or magnetic resonance imaging. TFESI was performed at patient's request. Additional injections, up to 3 times, were given with an interval of 7 or 10 days. The injection medicine consisted of 25 mg of prednisolone acetate and (9 - 14) ml of 0.5% lidocaine. Patients were evaluated by an independent observer and received questionnaires before the initial injection and at 6, 12 months after TFESI. Questionnaires included an eleven points visual analog scale (VAS) and a five points patient satisfaction scale. A successful outcome required a patient satisfaction scale score of 3 (very good) or 4 (excellent) and a reduction on the VAS score of 2 or more points after TFESI. Pain relief was classified as "excellent" when the pain was completely resolved or diminished by 5 points or more, as "good" when a diminution of pain was 2 points or more, as "fair" and "poor" when a diminution of pain was 1 point or less, or even an increase in pain. Results Twenty-nine patients received single injection, 22 patients received two, 15 patients receivedthree and 13 patients received four times of injection, with a mean of 1.96 times per patient. The mean VAS scores were 6.5 (ranged 3.5 - 9.5) before and 3.8 (ranged 0 - 9.5) 6 months after the procedure. Pain relief was graded as excellent in 35 patients (44.3%), good in 26 patients (32.9%), fair in 10 patients (12.7%), and poor in

  5. Heavy Metal Pad Shielding during Fluoroscopic Interventions

    Dromi, Sergio; Wood, Bradford J.; Oberoi, Jay; Neeman, Ziv


    Significant direct and scatter radiation doses to patient and physician may result from routine interventional radiology practice. A lead-free disposable tungsten antimony shielding pad was tested in phantom patients during simulated diagnostic angiography procedures. Although the exact risk of low doses of ionizing radiation is unknown, dramatic dose reductions can be seen with routine use of this simple, sterile pad made from lightweighttungsten antimony material.

  6. 21 CFR 1020.32 - Fluoroscopic equipment.


    ... the barrier with the attenuation block in the useful beam combined with radiation from the... during the measurement. For all measurements, the attenuation block shall be positioned in the useful... visible area of the image receptor by more than 3 percent of the SID. The sum of the excess length and...

  7. Skin dose mapping for fluoroscopically guided interventions

    Johnson, Perry B.; Borrego, David; Balter, Stephen; Johnson, Kevin; Siragusa, Daniel; Bolch, Wesley E. [Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Radiology, Columbia University Medical Center, New York, New York 10032 (United States); Radiology, University of Florida, Jacksonville, Florida 32209 (United States); Radiology, Division of Vascular Interventional Radiology, University of Florida, Jacksonville, Florida 32209 (United States); Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States)


    Purpose: To introduce a new skin dose mapping software system for interventional fluoroscopy dose assessment and to analyze the benefits and limitations of patient-phantom matching. Methods: In this study, a new software system was developed for visualizing patient skin dose during interventional fluoroscopy procedures. The system works by translating the reference point air kerma to the location of the patient's skin, which is represented by a computational model. In order to orient the model with the x-ray source, geometric parameters found within the radiation dose structured report (RDSR) are used along with a limited number of in-clinic measurements. The output of the system is a visual indication of skin dose mapped onto an anthropomorphic model at a resolution of 5 mm. In order to determine if patient-dependent and patient-sculpted models increase accuracy, peak skin dose was calculated for each of 26 patient-specific models and compared with doses calculated using an elliptical stylized model, a reference hybrid model, a matched patient-dependent model and one patient-sculpted model. Results were analyzed in terms of a percent difference using the doses calculated using the patient-specific model as the true standard. Results: Anthropometric matching, including the use of both patient-dependent and patient-sculpted phantoms, was shown most beneficial for left lateral and anterior-posterior projections. In these cases, the percent difference using a reference model was between 8 and 20%, using a patient-dependent model between 7 and 15%, and using a patient-sculpted model between 3 and 7%. Under the table tube configurations produced errors less than 5% in most situations due to the flattening affects of the table and pad, and the fact that table height is the main determination of source-to-skin distance for these configurations. In addition to these results, several skin dose maps were produced and a prototype display system was placed on the in-clinic monitor of an interventional fluoroscopy system. Conclusions: The skin dose mapping program developed in this work represents a new tool that, as the RDSR becomes available through automated export or real-time streaming, can provide the interventional physician information needed to modify behavior when clinically appropriate. The program is nonproprietary and transferable, and also functions independent to the software systems already installed on the control room workstation. The next step will be clinical implementation where the workflow will be optimized along with further analysis of real-time capabilities.

  8. 胸部CT与钡餐透视检查对食管癌诊断价值研究%Research on Value of Chest CT and Barium Meal Fluoroscopic Examination in Diagnosis of Esophagus Cancer



    Objective To discuss the application value of chest barium meal fluoroscopy, CT and gastroscope in diagnosis of esophagus cancer. Methods 76 cases of patients with esophagus cancer diagnosed in our hospital from January 2014 to De-cember 2015 were selected, 44 cases of patients with benign lesions of pars oesophagea treated at the same period were se-lected for comparison, the different examination methods included barium meal fluoroscopy, CT and bronchoscope, all pa-tients received the above examinations, and the diagnostic accuracy of various methods was compared and analyzed. Results The diagnostic accuracy rates of barium meal fluoroscopy, CT and gastroscope for esophagus cancer were respectively 67.11%, 90.79% and 92.11%, the diagnostic accuracy rate of CT and gastroscope for esophagus cancer was higher than that of barium meal fluoroscopic diagnosis, the diagnostic accuracy rate of CT for lesions of pars oesophagea was higher than that of barium meal fluoroscopy with statistical difference(χ2=5.37, P0.05). Conclusion Chest barium meal fluoroscopy can be in the first place in the initial diagnosis and screening of esophagus cancer in clinic, and the CT and gastroscope can be used for further examination, which is of impor-tant significance to improve the diagnosis rate of esophagus cancer in clinic.%目的:探讨胸部钡餐透视、CT和胃镜对食管癌诊断的应用价值。方法整群选取该医院2014年1月—2015年12月间就诊的76例食管癌患者作为研究对象,选取同期44例食管部良性病变患者作为对照,并根据检查方法的不同分为钡餐透视、CT、支气管镜,所有患者均进行以上检查,对比和分析各种方法在诊断中的准确性。结果钡餐透视对食管癌的诊断准确率为67.11%,CT为90.79%,胃镜为92.11%,CT与胃镜对食管癌的诊断准确率高于钡餐透视诊断,对食管部病变的诊断准确率CT高于钡餐透视,差异有统计学意义(χ2=5.37,P0.05

  9. 经皮胃造瘘术在治疗恶性肿瘤所致继发性吞咽困难中的应用%Clinical application of percutaneous fluoroscopic gastrostomy in the treatment of secondary dysphagia caused by malignancy

    易小宇; 何伟; 余雷


    目的 分析经皮胃造瘘术在治疗恶性肿瘤所致继发性吞咽困难中的应用.方法 选择15例因头颈部恶性肿瘤导致无法进食、胃肠功能仍存在、需依赖静脉内营养患者,在局麻下行透视下经皮胃造瘘术.结果 15例均操作成功,1例术后出现严重并发症,3例出现轻微并发症,经处理后恢复正常.15例患者术后均摆脱静脉内营养,行肠内营养支持,明显提高生活质量.结论 透视下经皮胃造瘘术操作简单、易行,并发症可控可处理,特别适用于头颈部恶性肿瘤所致进食困难的患者.%Objective To summarize the clinical experience of percutaneous fluoroscopic gastrostomy (PFG) in the treatment of secondary dysphagia caused by malignancy.Methods Fifteen head and neck cancer patients with swallowing disorders (12 men,3 women; age range:48-76 years ; mean:54 years) underwent PFG.Radiopaque gastrostomy feeding catheter was placed with Seldinger technique under fluoroscopic guidance.Results All patients had technically successful placement of PFG tubes.One patient had serious complications and three patients had minor complications,which resolved after treatment.Parenteral nutrition was no longer required in all patients.Condusions PEG is a safe,effective and minimally-invasive procedure for nutrition support therapy in head and neck cancer patients with swallowing disorders.

  10. X线透视联合超声引导行经皮肝穿胆道引流术治疗梗阻性黄疸的临床应用%Percutaneous transhepatic biliary drainage under fluoroscopic and ultrasound guidance for the treatment of obstructive jaundice: its clinical application

    王建雄; 刘维; 窦晓霞; 王健; 宋莉; 佟小强; 邹英华


    Objective To investigate the technical and clinical value of percutaneous transhepatic biliary drainage (PTBD) in treating patients of obstructive jaundice with the help of fluoroscopic and realtime ultrasound monitoring. Methods A total of 78 patients with obstructive jaundice were enrolled in this study. The primary lesions included malignant diseases (n = 70) and benign diseases (n = 8). PTBD was carried out in all patients. Under fluoroscopic and real-time ultrasonography guidance, the biliary duct of the right hepatic lobe (n = 52) or the biliary duct of the left hepatic lobe was punctured and the cholangiography was routinely performed. the drainage procedure was carried out. Results PTBD was successfully accomplished in all patients. No severe complications, such as massive bleeding or biliary peritonitis, occurred. After the treatment the symptoms and signs of obstructive jaundice were gradually improved. The serum levels of both bitirubin and transaminase determined 1-2 weeks after the treatment were decreased, and the reductions were statistically significant when compared with the preoperative data (P < 0.01). Conclusion For the obstructive jaundice, PTBD under the guidance of fluoroscopy and realtime ultrasonography is an effective, safe, simple and economical treatment with fewer complications. (J Intervent Radiol, 2012, 21: 309-313)%目的 分析X线透视联合超声实时引导下经皮肝穿胆道引流术(PTBD)治疗阻塞性黄疸的操作技术及其应用价值.方法 78例阻塞性黄疸患者,其中70例为恶性阻塞性病变,8例为良性阻塞性病变,在超声实时引导结合X线透视下行PTBD术,穿刺右叶胆管52例,穿刺左叶胆管26例,并常规造影.结果所有患者手术均获得成功,未出现大出血及胆汁性腹膜炎等并发症,术后梗阻性黄疸症状逐渐改善,术后1~2周血清胆红素及转氨酶水平较术前明显下降(P<0.01).结论 X线透视结合超声实时引导下PTBD是一种治疗阻

  11. 无X线监视内镜下置入幽门支架治疗胃出口恶性梗阻36例%Treatment of malignant gastric outlet obstruction by endoscopically implanting pyloric stents without fluoroscopic guidance: an analysis of 36 cases

    吴齐; 李士杰; 曹长琦; 张集昌


    AIM: To evaluate the feasibility, efficacy, and complications of endoscopic placement of pyloric stents without fluoroscopic guidance in patients with malignant gastric outlet obstruction.METHODS: The clinical data for 36 patients with malignant gastric outlet obstruction who underwent endoscopic placement of pyloric stents between January 2007 and December 2009 were analyzed retrospectively.RESULTS: Thirty-six patients received a total of 39 stents, one stent each in 33 patients and two stents each in three patients.In seven patients with high-grade stenosis, endoscopic balloon dilatation was performed before stent insertion.Successful stent implantation was achieved in all patients.The gastric outlet obstruction score system (GOOSS) score was significantly increased within 1 and 4 weeks after stent placement (P = 0.000).The mean duration was increased 101.3 days (7-380 days).The mean survival time was 123.3 days (10-380 days).Device-related adverse events included stent migration (n = 2, day 20 and day 65), stent occlusion caused by tumor infiltration (n = 2), and acute cholangitis (n = 1,day 7).No hemorrhage or perforation occurred.CONCLUSION: Endoscopic implantation of pyloric stents without fluoroscopic guidance is a simple, safe and effective method for malignant gastric outlet obstruction.%目的:评价无X线监视内镜下置入幽门支架治疗胃出口恶性梗阻的操作技术、临床疗效及并发症.方法:对2007-01/2009-12接受无X线监视内镜下幽门支架置入治疗的36例胃出口恶性梗阻患者的临床资料进行回顾性分析.结果:36例患者共置入39枚支架,其中3例患者为双支架.7例患者因病变狭窄程度高,先行内镜下球囊扩张,再行支架置入.支架置入成功率100%.患者术后1 wk及4 wk的GOOSS评分高于术前,且差异具有统计学意义(P=0.000).患者GOOSS评分高于术前时间平均为101.3(7-380)d.患者平均生存期123.3(10-380)d.2例患者发生术后支架移位(20 d及65 d).2

  12. Patients exposure from fluoroscopic guided pacemaker implantation procedures

    Alkhorayef, M.; Babikir, E. [King Saud University, College of Applied Sciences, Radiological Sciences Department, P. O. Box 10219, Riyadh 11433 (Saudi Arabia); Sulieman, A. [Prince Sattam bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, P. O. Box 422, Alkharj 11942 (Saudi Arabia); Daar, E. [University of Jordan, Faculty of Science, Department of Physics, Amman 11942 (Jordan); Alnaaimi, M.; Alduaij, M. [Kuwait Cancer Control Centre, Department of Nuclear Medicine, Shwiekh (Kuwait); Bradley, D., E-mail: [University of Surrey, Centre for Nuclear and Radiation Physics, Guildford, Surrey, GU2 7XH (United Kingdom)


    A pacemaker, which is used for heart re synchronization with electrical impulses, is used to manage many clinical conditions. Recently, the frequency of the pacemaker implantation procedures increased 50% worldwide. During this procedure, patients and staff can be exposed to excessive radiation exposure. Wide range of doses was reported in previous studies, suggesting that optimization of this procedure is not fulfilled yet. This study aims to evaluate the patient and staff radiation doses during cardiac pacemaker procedure and quantify the patient effective dose. A total of 145 procedures were performed for five pacemakers procedures (VVI, VVIR, VVD, VVDR and DDDR) two hospitals were evaluated. Patients doses were measured using the kerma-area product meter. Effective doses were estimated using software based on Monte Carlo simulation from National Radiological Protection Board. The effective dose values were used to estimate the cancer risk from pacemaker procedure. Patients demographic data, exposure parameters for both fluoroscopy and radiography were quantified. The mean patients doses (Gy. cm{sup 2}) for VVI, VVIR, VVD, VVDR and DDDR was 1.52±0.13 (1.43-1.61), 3.28±2.34 (0.29-8.73), 3.04±1.67 (1.57-4.86), 6.04±2.326 and 19.2±3.6 (5.43-30.2), respectively, per procedure. The overall patients effective dose is 1.1 mSv per procedure. (Author)

  13. Logarithmic amplifier for computed tomography tasks using fluoroscopic projections.

    Buliev, I; Badea, C; Pallikarakis, N


    The image intensifier (II)-based imaging systems, as radiotherapy simulators or C-arm X-ray units, have also been used for image acquisition in computed tomography. When analogue-to-digital conversion is performed on the output signal of the television camera, the accuracy for low-amplitude video signals, corresponding to X-ray pathways crossing high attenuation structures, is limited. To deal with this lack of accuracy, we investigated the benefits of using a logarithmic amplifier (LOGAMP) inserted between the television camera output and the analogue-to-digital converter (ADC) in the image acquisition chain. Such a device was intended to provide better use of the available ADCs of a given resolution and actually to reduce the quantization noise. Simulated data were used in this study, and cases with and without logarithmic amplifier were compared. Based on the simulation results, we formulate requirements for several signal and acquisition system parameters where the use of such a circuit is recommended.

  14. Torsional dynamics of steerable needles: modeling and fluoroscopic guidance.

    Swensen, John P; Lin, MingDe; Okamura, Allison M; Cowan, Noah J


    Needle insertions underlie a diversity of medical interventions. Steerable needles provide a means by which to enhance existing needle-based interventions and facilitate new ones. Tip-steerable needles follow a curved path and can be steered by twisting the needle base during insertion, but this twisting excites torsional dynamics that introduce a discrepancy between the base and tip twist angles. Here, we model the torsional dynamics of a flexible rod-such as a tip-steerable needle-during subsurface insertion and develop a new controller based on the model. The torsional model incorporates time-varying mode shapes to capture the changing boundary conditions inherent during insertion. Numerical simulations and physical experiments using two distinct setups-stereo camera feedback in semitransparent artificial tissue and feedback control with real-time X-ray imaging in optically opaque artificial tissue-demonstrate the need to account for torsional dynamics in control of the needle tip.

  15. Detection of respiratory motion in fluoroscopic images for adaptive radiotherapy

    Moser, T; Nill, S; Remmert, G; Bendl, R [German Cancer Research Center, Heidelberg (Germany); Biederer, J [Department of Diagnostic Radiology, University Hospital Schleswig-Holstein, Kiel (Germany)], E-mail:


    Respiratory motion limits the potential of modern high-precision radiotherapy techniques such as IMRT and particle therapy. Due to the uncertainty of tumour localization, the ability of achieving dose conformation often cannot be exploited sufficiently, especially in the case of lung tumours. Various methods have been proposed to track the position of tumours using external signals, e.g. with the help of a respiratory belt or by observing external markers. Retrospectively gated time-resolved x-ray computed tomography (4D CT) studies prior to therapy can be used to register the external signals with the tumour motion. However, during treatment the actual motion of internal structures may be different. Direct control of tissue motion by online imaging during treatment promises more precise information. On the other hand, it is more complex, since a larger amount of data must be processed in order to determine the motion. Three major questions arise from this issue. Firstly, can the motion that has occurred be precisely determined in the images? Secondly, how large must, respectively how small can, the observed region be chosen to get a reliable signal? Finally, is it possible to predict the proximate tumour location within sufficiently short acquisition times to make this information available for gating irradiation? Based on multiple studies on a porcine lung phantom, we have tried to examine these questions carefully. We found a basic characteristic of the breathing cycle in images using the image similarity method normalized mutual information. Moreover, we examined the performance of the calculations and proposed an image-based gating technique. In this paper, we present the results and validation performed with a real patient data set. This allows for the conclusion that it is possible to build up a gating system based on image data, solely, or (at least in avoidance of an exceeding exposure dose) to verify gates proposed by the various external systems.

  16. Theoretical performance analysis for CMOS based high resolution detectors.

    Jain, Amit; Bednarek, Daniel R; Rudin, Stephen


    High resolution imaging capabilities are essential for accurately guiding successful endovascular interventional procedures. Present x-ray imaging detectors are not always adequate due to their inherent limitations. The newly-developed high-resolution micro-angiographic fluoroscope (MAF-CCD) detector has demonstrated excellent clinical image quality; however, further improvement in performance and physical design may be possible using CMOS sensors. We have thus calculated the theoretical performance of two proposed CMOS detectors which may be used as a successor to the MAF. The proposed detectors have a 300 μm thick HL-type CsI phosphor, a 50 μm-pixel CMOS sensor with and without a variable gain light image intensifier (LII), and are designated MAF-CMOS-LII and MAF-CMOS, respectively. For the performance evaluation, linear cascade modeling was used. The detector imaging chains were divided into individual stages characterized by one of the basic processes (quantum gain, binomial selection, stochastic and deterministic blurring, additive noise). Ranges of readout noise and exposure were used to calculate the detectors' MTF and DQE. The MAF-CMOS showed slightly better MTF than the MAF-CMOS-LII, but the MAF-CMOS-LII showed far better DQE, especially for lower exposures. The proposed detectors can have improved MTF and DQE compared with the present high resolution MAF detector. The performance of the MAF-CMOS is excellent for the angiography exposure range; however it is limited at fluoroscopic levels due to additive instrumentation noise. The MAF-CMOS-LII, having the advantage of the variable LII gain, can overcome the noise limitation and hence may perform exceptionally for the full range of required exposures; however, it is more complex and hence more expensive.

  17. Workflow for the use of a high-resolution image detector in endovascular interventional procedures

    Rana, R.; Loughran, B.; Swetadri Vasan, S. N.; Pope, L.; Ionita, C. N.; Siddiqui, A.; Lin, N.; Bednarek, D. R.; Rudin, S.


    Endovascular image-guided intervention (EIGI) has become the primary interventional therapy for the most widespread vascular diseases. These procedures involve the insertion of a catheter into the femoral artery, which is then threaded under fluoroscopic guidance to the site of the pathology to be treated. Flat Panel Detectors (FPDs) are normally used for EIGIs; however, once the catheter is guided to the pathological site, high-resolution imaging capabilities can be used for accurately guiding a successful endovascular treatment. The Micro-Angiographic Fluoroscope (MAF) detector provides needed high-resolution, high-sensitivity, and real-time imaging capabilities. An experimental MAF enabled with a Control, Acquisition, Processing, Image Display and Storage (CAPIDS) system was installed and aligned on a detector changer attached to the C-arm of a clinical angiographic unit. The CAPIDS system was developed and implemented using LabVIEW software and provides a user-friendly interface that enables control of several clinical radiographic imaging modes of the MAF including: fluoroscopy, roadmap, radiography, and digital-subtraction-angiography (DSA). Using the automatic controls, the MAF detector can be moved to the deployed position, in front of a standard FPD, whenever higher resolution is needed during angiographic or interventional vascular imaging procedures. To minimize any possible negative impact to image guidance with the two detector systems, it is essential to have a well-designed workflow that enables smooth deployment of the MAF at critical stages of clinical procedures. For the ultimate success of this new imaging capability, a clear understanding of the workflow design is essential. This presentation provides a detailed description and demonstration of such a workflow design.

  18. Generalized two-dimensional (2D) linear system analysis metrics (GMTF, GDQE) for digital radiography systems including the effect of focal spot, magnification, scatter, and detector characteristics

    Kuhls-Gilcrist, Andrew T.; Gupta, Sandesh K.; Bednarek, Daniel R.; Rudin, Stephen


    The MTF, NNPS, and DQE are standard linear system metrics used to characterize intrinsic detector performance. To evaluate total system performance for actual clinical conditions, generalized linear system metrics (GMTF, GNNPS and GDQE) that include the effect of the focal spot distribution, scattered radiation, and geometric unsharpness are more meaningful and appropriate. In this study, a two-dimensional (2D) generalized linear system analysis was carried out for a standard flat panel detector (FPD) (194-micron pixel pitch and 600-micron thick CsI) and a newly-developed, high-resolution, micro-angiographic fluoroscope (MAF) (35-micron pixel pitch and 300-micron thick CsI). Realistic clinical parameters and x-ray spectra were used. The 2D detector MTFs were calculated using the new Noise Response method and slanted edge method and 2D focal spot distribution measurements were done using a pin-hole assembly. The scatter fraction, generated for a uniform head equivalent phantom, was measured and the scatter MTF was simulated with a theoretical model. Different magnifications and scatter fractions were used to estimate the 2D GMTF, GNNPS and GDQE for both detectors. Results show spatial non-isotropy for the 2D generalized metrics which provide a quantitative description of the performance of the complete imaging system for both detectors. This generalized analysis demonstrated that the MAF and FPD have similar capabilities at lower spatial frequencies, but that the MAF has superior performance over the FPD at higher frequencies even when considering focal spot blurring and scatter. This 2D generalized performance analysis is a valuable tool to evaluate total system capabilities and to enable optimized design for specific imaging tasks. PMID:21243038

  19. SU-E-I-40: New Method for Measurement of Task-Specific, High-Resolution Detector System Performance

    Loughran, B; Singh, V; Jain, A; Bednarek, D; Rudin, S [University at Buffalo, Buffalo, NY (United States)


    Purpose: Although generalized linear system analytic metrics such as GMTF and GDQE can evaluate performance of the whole imaging system including detector, scatter and focal-spot, a simplified task-specific measured metric may help to better compare detector systems. Methods: Low quantum-noise images of a neuro-vascular stent with a modified ANSI head phantom were obtained from the average of many exposures taken with the high-resolution Micro-Angiographic Fluoroscope (MAF) and with a Flat Panel Detector (FPD). The square of the Fourier Transform of each averaged image, equivalent to the measured product of the system GMTF and the object function in spatial-frequency space, was then divided by the normalized noise power spectra (NNPS) for each respective system to obtain a task-specific generalized signal-to-noise ratio. A generalized measured relative object detectability (GM-ROD) was obtained by taking the ratio of the integral of the resulting expressions for each detector system to give an overall metric that enables a realistic systems comparison for the given detection task. Results: The GM-ROD provides comparison of relative performance of detector systems from actual measurements of the object function as imaged by those detector systems. This metric includes noise correlations and spatial frequencies relevant to the specific object. Additionally, the integration bounds for the GM-ROD can be selected to emphasis the higher frequency band of each detector if high-resolution image details are to be evaluated. Examples of this new metric are discussed with a comparison of the MAF to the FPD for neuro-vascular interventional imaging. Conclusion: The GM-ROD is a new direct-measured task-specific metric that can provide clinically relevant comparison of the relative performance of imaging systems. Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation.

  20. New family of generalized metrics for comparative imaging system evaluation

    Russ, M.; Singh, V.; Loughran, B.; Bednarek, D. R.; Rudin, S.


    A family of imaging task-specific metrics designated Relative Object Detectability (ROD) metrics was developed to enable objective, quantitative comparisons of different x-ray systems. Previously, ROD was defined as the integral over spatial frequencies of the Fourier Transform of the object function, weighted by the detector DQE for one detector, divided by the comparable integral for another detector. When effects of scatter and focal spot unsharpness are included, the generalized metric, GDQE, is substituted for the DQE, resulting in the G-ROD metric. The G-ROD was calculated for two different detectors with two focal spot sizes using various-sized simulated objects to quantify the improved performance of new high-resolution CMOS detector systems. When a measured image is used as the object, a Generalized Measured Relative Object Detectability (GM-ROD) value can be generated. A neuro-vascular stent (Wingspan) was imaged with the high-resolution Micro-Angiographic Fluoroscope (MAF) and a standard flat panel detector (FPD) for comparison using the GM-ROD calculation. As the lower integration bound increased from 0 toward the detector Nyquist frequency, increasingly superior performance of the MAF was evidenced. Another new metric, the R-ROD, enables comparing detectors to a reference detector of given imaging ability. R-RODs for the MAF, a new CMOS detector and an FPD will be presented. The ROD family of metrics can provide quantitative more understandable comparisons for different systems where the detector, focal spot, scatter, object, techniques or dose are varied and can be used to optimize system selection for given imaging tasks.

  1. Overcoming x-ray tube small focal spot output limitations for high resolution region of interest imaging

    Gupta, Sandesh K.; Jain, Amit; Bednarek, Daniel R.; Rudin, Stephen


    We investigate methods to increase x-ray tube output to enable improved quantum image quality with a higher generalized-NEQ (GNEQ) while maintaining a small focal-spot size for the new high-resolution Micro-angiographic Fluoroscope (MAF) Region of Interest (ROI) imaging system. Rather than using a larger focal spot to increase tubeloading capacity with degraded resolution, we evaluated separately or in combination three methods to increase tube output: 1) reducing the anode angle and lengthening the filament to maintain a constant effective small focal-spot size, 2) using the standard medium focal spot viewed from a direction on the anode side of the field and 3) increasing the frame rate (frames/second) in combination with temporal filter. The GNEQ was compared for the MAF for the small focal-spot at the central axis, and for the medium focal-spot with a higher output on the anode side as well as for the small focal spot with different temporal recursive filtering weights. A net output increase of about 4.0 times could be achieved with a 2-degree anode angle (without the added filtration) and a 4 times longer filament compared to that of the standard 8-degree target. The GNEQ was also increased for the medium focal-spot due to its higher output capacity and for the temporally filtered higher frame rate. Thus higher tube output, while maintaining a small effective focal-spot, should be achievable using one or more of the three methods described with only small modifications of standard x-ray tube geometry.

  2. Fluoroscopic lumbar interlaminar epidural injections in managing chronic lumbar axial or discogenic pain

    Manchikanti L; Cash KA; McManus CD; Pampati V; Benyamin R


    Laxmaiah Manchikanti,1,2 Kimberly A Cash,1 Carla D McManus,1 Vidyasagar Pampati,1 Ramsin Benyamin3,41Pain Management Center of Paducah, Paducah, KY; 2University of Louisville, Louisville, KY; 3Millennium Pain Center, Bloomington, IL; 4University of Illinois, Urbana-Champaign, IL, USAAbstract: Among the multiple causes of chronic low back pain, axial and discogenic pain are common. Various modalities of treatments are utilized in managing discogenic and axial low back pain including e...

  3. Fluoroscopic lumbar interlaminar epidural injections in managing chronic lumbar axial or discogenic pain.

    Manchikanti, Laxmaiah; Cash, Kimberly A; McManus, Carla D; Pampati, Vidyasagar; Benyamin, Ramsin


    Among the multiple causes of chronic low back pain, axial and discogenic pain are common. Various modalities of treatments are utilized in managing discogenic and axial low back pain including epidural injections. However, there is a paucity of evidence regarding the effectiveness, indications, and medical necessity of any treatment modality utilized for managing axial or discogenic pain, including epidural injections. In an interventional pain management practice in the US, a randomized, double-blind, active control trial was conducted. The objective was to assess the effectiveness of lumbar interlaminar epidural injections of local anesthetic with or without steroids for managing chronic low back pain of discogenic origin. However, disc herniation, radiculitis, facet joint pain, or sacroiliac joint pain were excluded. Two groups of patients were studied, with 60 patients in each group receiving either local anesthetic only or local anesthetic mixed with non-particulate betamethasone. Primary outcome measures included the pain relief-assessed by numeric rating scale of pain and functional status assessed by the, Oswestry Disability Index, Secondary outcome measurements included employment status, and opioid intake. Significant improvement or success was defined as at least a 50% decrease in pain and disability. Significant improvement was seen in 77% of the patients in Group I and 67% of the patients in Group II. In the successful groups (those with at least 3 weeks of relief with the first two procedures), the improvement was 84% in Group I and 71% in Group II. For those with chronic function-limiting low back pain refractory to conservative management, it is concluded that lumbar interlaminar epidural injections of local anesthetic with or without steroids may be an effective modality for managing chronic axial or discogenic pain. This treatment appears to be effective for those who have had facet joints as well as sacroiliac joints eliminated as the pain source.

  4. PFO closure with only fluoroscopic guidance: 7 years real-world single centre experience.

    Mangieri, Antonio; Godino, Cosmo; Montorfano, Matteo; Arioli, Francesco; Rosa, Isabella; Ajello, Silvia; Piraino, Daniela; Monello, Alberto; Pavon, Anna Giulia; Viani, Giacomo; Magni, Valeria; Cappelletti, Alberto; Margonato, Alberto; Colombo, Antonio


    To evaluate the safety and the efficacy of fluoroscopy-guided only (Fluo-G) and of echocardiography-guided (Echo-G; trans-esophageal echocardiography-TEE-or intracardiac echocardiography-ICE) percutaneous closure of patent foramen ovale (PFO). Single center retrospective registry enrolling 368 consecutive patients (mean age 50.5 years) who underwent PFO closure between June 2004 and December 2011. Most patients had prior cryptogenic stroke (n = 126; 34.2%), TIA (n = 218; 51.1%); some of these had recurrent neurological events [multiple strokes n = 28 (7.8%); multiple TIAs n = 72 (18.6%)]. All the patients underwent a preprocedure TEE. PFO closure was performed with Echo-G in 187 patients (50.8%) (TEE n = 69, 36.8% and ICE n = 124, 66.3%). In Fluo-G cases, PFO with atrial septal aneurysm (ASA) was significantly less present (P Fluo-G group (P Fluo-G vs. 98.3% Echo-G) and RtL-shunt at follow-up (11.7% Fluo-G vs. 7.6% Echo-G). The rate of conversion from Fluoro-G to Echo-G procedure was 4.4% (n = 8). At a median follow-up of 4 years, freedom from recurrent embolic events rate was similar between the two groups (Echo-G 94.5 vs. Fluo-G 95.7%). In our experience Fluoro-G PFO closure was performed mainly in cases of simple anatomy, with similar results in terms of safety and efficacy compared to Echo-G cases. Both fluoroscopy and total procedural times were lower in the Fluo-G cases. © 2015 Wiley Periodicals, Inc.

  5. 'Zero' fluoroscopic exposure for ventricular tachycardia ablation in a patient with situs viscerum inversus totalis.

    Giaccardi, Marzia; Chiodi, Leandro; Del Rosso, Attilio; Colella, Andrea


    Situs viscerum inversus totalis (SVIT) is a congenital disorder characterized by mirror reversal of the thoracic and abdominal organs. Different studies have shown that the ablation procedure can be performed without fluoroscopy with safety and effectiveness, in the setting of supraventricular tachycardia. We successfully performed an anatomical map and a radiofrequency catheter ablation of ventricular arrhythmia in a patient with SVIT without fluoroscopy.

  6. Fluoroscopic insertion of post-pyloric feeding tubes: success rates and complications

    Thurley, P.D.; Hopper, M.A. [Department of Clinical Radiology, Nottingham University Hospitals NHS Trust, Nottingham (United Kingdom); Jobling, J.C. [Department of Clinical Radiology, Nottingham University Hospitals NHS Trust, Nottingham (United Kingdom)], E-mail:; Teahon, K. [Department of Clinical Radiology, Nottingham University Hospitals NHS Trust, Nottingham (United Kingdom)


    Aim: To examine the success and complication rates of radiological placement of post-pyloric feeding tubes, including those inserted with the assistance of a guide-wire. Materials and Methods: Two hundred referrals (156 patients), between the dates of 5 April 2002 and 10 September 2004, were identified retrospectively from computerized records. Subsequently, the radiology reports and patients' notes were reviewed to evaluate the indications for post-pyloric feeding, success of placement, use of a guide-wire, and any complications. Results: A post-pyloric tube was placed in the distal duodenum/jejunum in 183 (91.5%) patients and in the proximal duodenum or distal stomach in six (3%). A tube could not be inserted in 11 (5.5%) patients, and 51 (25.5%) of the insertions required the use of a guide-wire. Immediate complications were recorded in seven patients (3.5%): vomiting (n = 5); hypotension and apnoea requiring naloxone (n = 1) and hypoxia requiring endotracheal intubation (n = 1). Conclusion: Radiological placement of post-pyloric feeding tubes has a success rate comparable with endoscopically placed tubes, and it rarely involves significant technique-related complications.

  7. Fluoroscopically Guided Interventional Procedures: A Review of Radiation Effects on Patients’ Skin and Hair


    ters below the skin . The build-up of dose below the surface can minimize injury of skin . This is often called skin sparing . Because orthovoltage...radiation ther- apy does not exhibit skin sparing , clini- cal radiation therapy with orthovoltage equipment was prescribed in a manner that... skin reaction in deep therapy as a function of size of the fi eld: a law for radiotherapy [in German] . Fortschr Geb Rontgenstr 1955 ; 82 : 387

  8. Fluoroscopic guided fogarty embolectomy for an angio-seal embolism in the popliteal artery

    Hong, Dong; Lee, Seung Hwa; Chung, Hwan Hoon; Seo, Bo Kyoung; Cha, Sang Hoon; Lee, Kee Yeol; Ahn, Jeong Cheon [Korea University Ansan Hospital, College of Medicine, Korea University, Ansan (Korea, Republic of)


    The Angio-Seal is a widely used arterial closure device that helps achieve faster hemostasis and provide early ambulation to patients. However, it can cause various complications in clinical practice. We present the uncommon complication of popliteal artery occlusion following Angio-Seal deployment, and describe an effective interventional approach to its treatment. Because fluoroscopy-guided Fogarty embolectomy has the advantages of complete removal of the embolus without fragmentation, and clear visualization of the exact location of the embolus during the procedure, it is a suitable method for treating this complication.

  9. Prospective nationwide fluoroscopic and electrical longitudinal follow-up of recalled Riata defibrillator leads in Denmark

    Larsen, Jacob M.; Nielsen, Jens Cosedis; Johansen, Jens B.;


    BACKGROUND Recalled St. Jude Medical Riata defibrillator leads are prone to insulation failures with externalized conductors (ECs). Longitudinal studies are needed to guide lead management. OBJECTIVE The purpose of this study was to describe the dynamic nature of EC and the association with elect...... is a dynamic process despite long lead dwell time. ECs are associated with a higher risk of electrical abnormalities. Therefore, lead replacement should be considered, especially in patients with a long life expectancy....... with electrical abnormalities and lead extraction outcomes. METHODS A nationwide cohort established in 2012 of 295 patients with recalled Riata leads with dwell time 5.1 +/- 1.1 years, 34 ECs, and 19 electrical abnormalities were followed until death, lead discontinuation with fluoroscopy, or a new 2013 screening......-up in 27 patients with baseline EC showed an increase in EC length of 4 +/- 1 mm (P Electrical follow-up in 276 patients with normal baseline electrical function demonstrated 20 incident electrical abnormalities after 1.0 +/- 0.3 years, with an incidence rate of 7.1 per 100...

  10. Factors affecting exposure level for medical staff during orthopedic procedures under fluoroscopic control

    Maria A. Staniszewska


    Full Text Available Background: Extended control of staff exposure in interventional radiology has been legally required over the last few years. This is determined by a number of factors, including the type of procedure, technical conditions and methodology. In orthopedic procedures fluoroscopy is used to control surgical reconstructions. An influence of particular factors on the registered values of doses received by the members of medical team performing osteosynthesis for limb fractures is presented in this paper. Material and Methods: Doses received by individual interventional team members performing specific functions, operator, assisting physicians and scrub nurse, during a series of the procedures were measured. Each person was equipped with 4 dosimetric tools, containing thermoluminescent dosimeters, to measure the equivalent doses for the eyes, hand skin and the neck (outside the shield and to evaluate effective doses. The investigations were performed in operational theatres of 3 hospitals in Łódź. Results: The equivalent doses per one procedure for the eyes and hand skin of the operator were 0.029–0.073 mSv and 0.366–1.604 mSv, respectively. Significantly higher doses were noted during the procedures of intramedullary osteosynthesis, especially for the operator. An average age and body mass index (BMI of patients treated in the monitored hospitals did not differ statistically. Conclusions: Based on the dosimetric measurements the following conclusions can be drawn: in orthopedic procedures of interventional radiology (IR the exposure of the staff is mostly determined by the type of procedure and more precisely by its complexity and by the optimized use of X-ray unit, including pulsed fluoroscopy. It is also revealed that the operator is the most exposed person in the interventional team. Med Pr 2017;68(1:75–83

  11. Glenohumeral joint injection: a comparative study of ultrasound and fluoroscopically guided techniques before MR arthrography.

    Rutten, M.J.; Collins, J.M.; Maresch, B.J.; Smeets, J.H.R.; Janssen, C.M.; Kiemeney, L.A.L.M.; Jager, G.J.


    To assess the variability in accuracy of contrast media introduction, leakage, required time and patient discomfort in four different centres, each using a different image-guided glenohumeral injection technique. Each centre included 25 consecutive patients. The ultrasound-guided anterior (USa) and

  12. Radiation dose reduction in fluoroscopic procedures: left varicocele embolization as a model

    Verstandig, Anthony G.; Shraibman, Vladimir [Shaare Zedek Medical Center, Department of Radiology, Interventional Radiology Unit, POB 3235, Jerusalem (Israel); Shamieh, Bashar [St. Joseph Hospital, Department of Radiology, Jerusalem (Israel); Raveh, David [Shaare Zedek Medical Center, Infectious Diseases Unit, POB 3235, Jerusalem (Israel)


    To investigate the effect of a radiation reduction program on total dose, fluoroscopy dose per second corrected for body habitus and degree of collimation in left varicocele embolizations (LVE). A radiation reduction program for LVE was implemented, consisting of a technique minimizing fluoroscopy time, using low-dose presets, virtual collimation, and virtual patient positioning. Height, weight, fluoroscopy time, kerma area product (KAP) and reference air kerma (Ka,r) were recorded for 100 consecutive cases satisfying the inclusion criteria. For each patient, a device specific dose correction factor, determined using a phantom, was used to standardize the KAP to that of the cylindrical diameter of the standard man and a collimation index was derived from the KAP and Ka,r. Median fluoroscopy time was 3 minutes (mean 4.5, range 1-23.8). Median KAP was 0.54 Gy/cm{sup 2} (mean 0.82, range 0.12-6.52). There was a significant decrease in KAP/second corrected for cylindrical diameter (p < 0.001) and the collimation index (p < 0.001) over time. This study shows that a dedicated dose reduction program can achieve very low total radiation dose rates for LVE. The significant decrease in collimation index and standardized KAP per second during this study suggest a learning curve for collimation. (orig.)

  13. Fluoroscopic balloon-guided transesophageal echocardiography in a patient with Zenker's diverticulum.

    Fergus, Icilma; Bennett, Edward S; Rogers, David M; Siskind, Steven; Messineo, Frank C


    During the past 20 years, transesophageal echocardiography (TEE) became an important diagnostic technique. Indications for TEE include: defining the cause and severity of native valve disease, particularly mitral regurgitation; detecting vegetations and other sequelae of endocarditis; assessing prosthetic valve function; and identifying a potential cardiac source for emboli.(1) TEE is usually well tolerated and is associated with few adverse events. However, structural abnormalities of the esophagus such as diverticula, stenoses, tumors, and advanced varices are relative contraindications to TEE because of the technical difficulties associated with probe advancement and the risk of esophageal perforation.(2) This report describes the successful performance of TEE in a patient with a Zenker's diverticulum. The patient was severely symptomatic of atrial fibrillation and was a poor candidate for long-term anticoagulation. Therefore, it was necessary to rule out a thrombus before cardioversion. Because the Zenker's diverticulum was large, a novel approach was taken using a balloon to occlude the orifice allowing safe passage of the TEE probe.

  14. Percutaneous retrieval of malpositioned, kinked and unraveled guide wire under fluoroscopic guidance during central venous cannulation

    Gopal Krishan Jalwal


    Full Text Available The placement of central venous catheter using Seldinger′s technique, remains a commonly performed procedure with its own risks and benefits. Various complications have been reported with the use of guide wire as well as catheter. We report a unique problem during subclavian vein cannulation due to guidewire malposition which led to its kinking and difficult retrieval requiring removal in fluoroscopy suit. The probable mechanism of guide wire entrapment and possible bedside management of similar problems is described.

  15. Successful Non-fluoroscopic Radiofrequency Ablation of Incessant Atrial Tachycardia in a High Risk Twin Pregnancy.

    Zuberi, Zia; Silberbauer, John; Murgatroyd, Francis


    We describe a patient presenting with incessant ectopic atrial tachycardia during a high risk twin pregnancy. Tachycardia was resistant to escalating doses of beta-blockade with digoxin. Because of increasing left ventricular dysfunction early in the third trimester, catheter ablation was performed successfully at 30 weeks gestation. Electro-anatomic mapping permitted the entire procedure to be conducted without the use of ionizing radiation. The pregnancy proceeded to successful delivery near term and after three years the patient remains recurrence free with normal left ventricular function, off all medication.

  16. Angiographer's exposure to radiation under different fluoroscopic imaging conditions

    Iida, Hiroji; Ueda, Shinichi; Shimizu, Mitsuru; Tamura, Sakio [Kanazawa Univ. (Japan). Hospital; Koshida, Kichiro


    Scattered radiation levels near an imaging system commonly used in angiography were measured with a 200 mm thick water phantom. The scattered radiation exposure rate was measured in lines parallel in space to the central ray of the x-ray beam, at lateral distances of 30-100 cm. The effects of an x-ray beam limiting device, geometric and electric magnification, and rotation angle of the C-arm were also determined. The results indicated that the highest scattered radiation levels occurred near the surface of the phantom where the x-ray beam enters. In P-A geometry, the highest radiation levels occurred below the angiographer's waist. These areas of the body corresponded to the gonads of the angiographer. It has been suggested that angiographers' exposure rates are higher near the gonads than near the chest. However, lead aprons efficiently protect these areas. When smaller field sizes were limited by a variable x-ray beam limiting device, the volume of irradiated tissue was reduced, and the scattered radiation exposure rate was decreased. Further, when larger magnification factors were chosen for the analogue magnification method, the volume of irradiated tissue was reduced by the automatic x-ray beam limiting device, and the scattered radiation exposure rate was decreased. However, smaller field sizes markedly increased patient exposure by auto brightness control. To mitigate the angiographer's exposure, smaller field sizes with x-ray limiting devices are required. However, a larger field size should be used whenever possible to minimize patient exposure. The angiographer's exposure rate was influenced by the incidence direction of the x-ray beam when the C-arm had been rotated around the phantom. Consequently, the angiographer's exposure rate was maximum when the x-ray tube most closely approached the angiographer and was minimum when the image intensifier most closely approached the angiographer. Therefore, to mitigate the angiographer's exposure, attention needs to be given to the incidence direction of the x-ray beam. (author)

  17. Automatic segmentation of seeds and fluoroscope tracking (FTRAC) fiducial in prostate brachytherapy x-ray images

    Kuo, Nathanael; Lee, Junghoon; Deguet, Anton; Song, Danny; Burdette, E. Clif; Prince, Jerry


    C-arm X-ray fluoroscopy-based radioactive seed localization for intraoperative dosimetry of prostate brachytherapy is an active area of research. The fluoroscopy tracking (FTRAC) fiducial is an image-based tracking device composed of radio-opaque BBs, lines, and ellipses that provides an effective means for pose estimation so that three-dimensional reconstruction of the implanted seeds from multiple X-ray images can be related to the ultrasound-computed prostate volume. Both the FTRAC features and the brachytherapy seeds must be segmented quickly and accurately during the surgery, but current segmentation algorithms are inhibitory in the operating room (OR). The first reason is that current algorithms require operators to manually select a region of interest (ROI), preventing automatic pipelining from image acquisition to seed reconstruction. Secondly, these algorithms fail often, requiring operators to manually correct the errors. We propose a fast and effective ROI-free automatic FTRAC and seed segmentation algorithm to minimize such human intervention. The proposed algorithm exploits recent image processing tools to make seed reconstruction as easy and convenient as possible. Preliminary results on 162 patient images show this algorithm to be fast, effective, and accurate for all features to be segmented. With near perfect success rates and subpixel differences to manual segmentation, our automatic FTRAC and seed segmentation algorithm shows promising results to save crucial time in the OR while reducing errors.

  18. Fluoroscopic lumbar interlaminar epidural injections in managing chronic lumbar axial or discogenic pain

    Manchikanti L


    Full Text Available Laxmaiah Manchikanti,1,2 Kimberly A Cash,1 Carla D McManus,1 Vidyasagar Pampati,1 Ramsin Benyamin3,41Pain Management Center of Paducah, Paducah, KY; 2University of Louisville, Louisville, KY; 3Millennium Pain Center, Bloomington, IL; 4University of Illinois, Urbana-Champaign, IL, USAAbstract: Among the multiple causes of chronic low back pain, axial and discogenic pain are common. Various modalities of treatments are utilized in managing discogenic and axial low back pain including epidural injections. However, there is a paucity of evidence regarding the effectiveness, indications, and medical necessity of any treatment modality utilized for managing axial or discogenic pain, including epidural injections. In an interventional pain management practice in the US, a randomized, double-blind, active control trial was conducted. The objective was to assess the effectiveness of lumbar interlaminar epidural injections of local anesthetic with or without steroids for managing chronic low back pain of discogenic origin. However, disc herniation, radiculitis, facet joint pain, or sacroiliac joint pain were excluded. Two groups of patients were studied, with 60 patients in each group receiving either local anesthetic only or local anesthetic mixed with non-particulate betamethasone. Primary outcome measures included the pain relief-assessed by numeric rating scale of pain and functional status assessed by the, Oswestry Disability Index, Secondary outcome measurements included employment status, and opioid intake. Significant improvement or success was defined as at least a 50% decrease in pain and disability. Significant improvement was seen in 77% of the patients in Group I and 67% of the patients in Group II. In the successful groups (those with at least 3 weeks of relief with the first two procedures, the improvement was 84% in Group I and 71% in Group II. For those with chronic function-limiting low back pain refractory to conservative management, it is concluded that lumbar interlaminar epidural injections of local anesthetic with or without steroids may be an effective modality for managing chronic axial or discogenic pain. This treatment appears to be effective for those who have had facet joints as well as sacroiliac joints eliminated as the pain source.Keywords: lumbar disc herniation, axial or discogenic pain, lumbar interlaminar epidural injections, local anesthetic, steroids, controlled comparative local anesthetic blocks, NCT00681447

  19. SU-E-CAMPUS-I-04: Automatic Skin-Dose Mapping for An Angiographic System with a Region-Of-Interest, High-Resolution Detector

    Vijayan, S; Rana, V [Department of Physiology and Biophysics, Toshiba Stroke and Vascular Research Center (United States); Setlur Nagesh, S [Toshiba Stroke and Vascular Research Center (United States); Ionita, C [Department of Biomedical Engineering, University at Buffalo (State University of New York), Buffalo, NY (United States); Rudin, S [Department of Radiology, Department of Physiology and Biophysics, Toshiba Stroke and Vascular Research Center, Department of Biomedical Engineering, University at Buffalo (State University of New York), Buffalo, NY (United States); Bednarek, D [Department of Radiology, Department of Physiology and Biophysics, Toshiba Stroke and Vascular Research Center (United States)


    Purpose: Our real-time skin dose tracking system (DTS) has been upgraded to monitor dose for the micro-angiographic fluoroscope (MAF), a high-resolution, small field-of-view x-ray detector. Methods: The MAF has been mounted on a changer on a clinical C-Arm gantry so it can be used interchangeably with the standard flat-panel detector (FPD) during neuro-interventional procedures when high resolution is needed in a region-of-interest. To monitor patient skin dose when using the MAF, our DTS has been modified to automatically account for the change in scatter for the very small MAF FOV and to provide separated dose distributions for each detector. The DTS is able to provide a color-coded mapping of the cumulative skin dose on a 3D graphic model of the patient. To determine the correct entrance skin exposure to be applied by the DTS, a correction factor was determined by measuring the exposure at the entrance surface of a skull phantom with an ionization chamber as a function of entrance beam size for various beam filters and kVps. Entrance exposure measurements included primary radiation, patient backscatter and table forward scatter. To allow separation of the dose from each detector, a parameter log is kept that allows a replay of the procedure exposure events and recalculation of the dose components.The graphic display can then be constructed showing the dose distribution from the MAF and FPD separately or together. Results: The DTS is able to provide separate displays of dose for the MAF and FPD with field-size specific scatter corrections. These measured corrections change from about 49% down to 10% when changing from the FPD to the MAF. Conclusion: The upgraded DTS allows identification of the patient skin dose delivered when using each detector in order to achieve improved dose management as well as to facilitate peak skin-dose reduction through dose spreading. Research supported in part by Toshiba Medical Systems Corporation and NIH Grants R43FD0158401, R44FD

  20. SU-E-I-29: Generalized Relative Object Detectability (G-ROD): A Metric for Comparing X-Ray Imaging Detector Systems

    Singh, V; Jain, A; Bednarek, D; Rudin, S [Toshiba Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY (United States)


    Purpose: To determine the relative task-specific performance of two x-ray imaging detectors including the effect of other components of the imaging chain. Methods: The relative object detectability (ROD) was defined as the ratio of the integral of the detective-quantum efficiency (DQE) of a detector weighted by the square of the Fourier Transform (or frequency spectrum) of the object to the same integral for a second detector. The generalized ROD (G-ROD) is calculated by replacing DQE by the generalized DQE (GDQE) which includes geometric unsharpness and scatter to evaluate the total imaging chain. The G-ROD was calculated for the micro-angiographic fluoroscope (MAF) relative to a flat-panel detector (FPD) for low (1.05) and high (1.2) magnifications with two focal-spot sizes, small (0.3 mm) and medium (0.5 mm), and for the same value of scatter fraction. Solid spheres from 50 to 600 microns were simulated as the objects for this evaluation. The G-ROD results were compared with those of the ROD which considers the detectors alone. Results: For 50-micron spheres, the ROD is 7.93 and, for the small [medium] focus, the G-ROD is 6.74 [5.22] at low magnification and 3.03 [1.66] at high magnification, indicating superior performance of the MAF particularly at low magnification. Both ROD and G-ROD decrease monotonically with size and remain around one above 400-microns. The G-ROD decreases more dramatically with low compared to high magnification for both focal spots. Conclusion: In all cases, the MAF performs better than the FPD and the decreasing trend of the G-ROD indicates that the performance of both detectors becomes similar as the object size increases and becomes nearly equal above 400-micron diameter sphere size. Finally, increased magnification and focal-spot size decrease the G-ROD, indicting that they degrade the performance of the MAF more than that of the FPD for a small-object viewing task. Supported by NIH Grant: 2R01EB002873 and an equipment grant from

  1. Rotational micro-CT using a clinical C-arm angiography gantry

    Patel, V.; Hoffmann, K. R.; Ionita, C. N.; Keleshis, C.; Bednarek, D. R.; Rudin, S. [Toshiba Stroke Research Center, Department of Physics, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Neurosurgery, Department of Physics, Department of Physiology and Biophysics, Department of Mechanical and Aerospace Engineering, and Department of Computer Science, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Neurosurgery, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Electrical Engineering, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Radiology, Department of Neurosurgery, Department of Physics, and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Radiology, Department of Neurosurgery, Department of Physiology and Biophysics, Department of Mechanical and Aerospace Engineering, and Department of Electrical Engineering, State University of New York at Buffalo, Buffalo, New York 14214 (United States)


    Rotational angiography (RA) gantries are used routinely to acquire sequences of projection images of patients from which 3D renderings of vascular structures are generated using Feldkamp cone-beam reconstruction algorithms. However, these systems have limited resolution (<4 lp/mm). Micro-computed tomography (micro-CT) systems have better resolution (>10 lp/mm) but to date have relied either on rotating object imaging or small bore geometry for small animal imaging, and thus are not used for clinical imaging. The authors report here the development and use of a 3D rotational micro-angiography (RMA) system created by mounting a micro-angiographic fluoroscope (MAF) [35 {mu}m pixel, resolution >10 lp/mm, field of view (FOV)=3.6 cm] on a standard clinical FPD-based RA gantry (Infinix, Model RTP12303J-G9E, Toshiba Medical Systems Corp., Tustin, CA). RA image sequences are obtained using the MAF and reconstructed. To eliminate artifacts due to image truncation, lower-dose (compared to MAF acquisition) full-FOV (FFOV) FPD RA sequences (194 {mu}m pixel, FOV=20 cm) were also obtained to complete the missing data. The RA gantry was calibrated using a helical bead phantom. To ensure high-quality high-resolution reconstruction, the high-resolution images from the MAF were aligned spatially with the lower-dose FPD images, and the pixel values in the FPD image data were scaled to match those of the MAF. Images of a rabbit with a coronary stent placed in an artery in the Circle of Willis were obtained and reconstructed. The MAF images appear well aligned with the FPD images (average correlation coefficient before and after alignment: 0.65 and 0.97, respectively) Greater details without any visible truncation artifacts are seen in 3D RMA (MAF-FPD) images than in those of the FPD alone. The FWHM of line profiles of stent struts (100 {mu}m diameter) are approximately 192{+-}21 and 313{+-}38 {mu}m for the 3D RMA and FPD data, respectively. In addition, for the dual-acquisition 3D RMA

  2. Fluoroscopic caudal epidural injections in managing chronic axial low back pain without disc herniation, radiculitis, or facet joint pain

    Manchikanti L; Cash KA; McManus CD; Pampati V


    Laxmaiah Manchikanti,1,2 Kimberly A Cash,1 Carla D McManus,1 Vidyasagar Pampati11Pain Management Center of Paducah, Paducah, 2Department of Anesthesiology and Perioperative Medicine, University of Louisville, Louisville, KY, USABackground: Chronic low back pain without disc herniation is common. Various modalities of treatments are utilized in managing this condition, including epidural injections. However, there is continued debate on the effectiveness, indications, and medical necessity of ...

  3. Fluoroscopic x-ray demonstrator using a CdTe polycrystalline layer coupled to a CMOS readout chip

    Arques, M.; Renet, S.; Brambilla, A.; Feuillet, G.; Gasse, A.; Billon-Pierron, N.; Jolliot, M.; Mathieu, L.; Rohr, P.


    Dynamic X-ray imagers require large surface, fast and highly sensitive X-ray absorbers and dedicated readout electronics. Monocrystalline photoconductors offer the sensitivity, speed, and MTF performances. Polycristalline photoconductors offer the large surface at a moderate cost. The challenge for them is to maintain the first performances at a compatible level with the medical applications requirements. This work has been focused on polycristalline CdTe grown by Close Space Sublimation (CSS) technique. This technique offers the possibility to grow large layers with a high material evaporation yield. This paper presents the results obtained with an image demonstrator using 350μm thick CdTe_css layers coupled to a CMOS readout circuit with Indium bumping. The present demonstrator has 200 x 200 pixels, with a pixel pitch of 75μm ×75μm. A total image surface of 15mm × 15mm has then been obtained. The ASIC works in an integration mode, i.e. each pixel accumulates the charges coming from the CdTe layer on a capacitor, converting them to a voltage. Single images as well as video sequences have been obtained. X-ray performance at 16 frames per second rate is measured. In particular a readout noise of 0.5 X ray, an MTF of 50% at 4 lp/mm and a DQE of 20% at 4lp/mm and 600 nGy are obtained. Although present demonstrator surface is moderate, it demonstrates that high performance can be expected from this assembly concept and its interest for medical applications.

  4. Intra-operative dosimetry of trans-rectal ultrasound guided 125I prostate implants using C-arm fluoroscopic images

    Ravindran Paul


    Full Text Available Permanent implantation of radioactive seeds is a viable and effective therapeutic option widely used today for early-stage prostate cancer. The implant technique has improved considerably during the recent years due to the use of image guidance; however, real-time dose distributions would allow potential cold spots to be assessed and additional seeds added. In this study, we investigate the use of a conventional C-arm fluoroscopy unit for image acquisition and evaluation of dose distribution immediately after the implant. The phantom study indicates that it is possible to obtain seed positions within ±2 mm. A pilot study carried out with three patients indicated that it is possible to obtain seed positions and calculate the dose distribution with C-arm fluoroscopy and about 95% of the seeds were reconstructed within ±2 mm. The results could be further improved with better digital imaging.

  5. Fluoroscopic-Guided Radial Endobronchial Ultrasound Without Guide Sheath For Peripheral Pulmonary Lesions: A Safe And Efficient Combination.

    Casutt, Alessio; Prella, Maura; Beigelman-Aubry, Catherine; Fitting, Jean-William; Nicod, Laurent; Koutsokera, Angela; Lovis, Alban


    Several guidelines recommend computed tomography scans for populations with high-risk for lung cancer. The number of individuals evaluated for peripheral pulmonary lesions (PPL) will probably increase, and with it non-surgical biopsies. Associating a guidance method with a target confirmation technique has been shown to achieve the highest diagnostic yield, but the utility of bronchoscopy with radial probe endobronchial ultrasound using fluoroscopy as guidance without a guide sheath has not been reported. We conducted a retrospective analysis of bronchoscopy with radial probe endobronchial ultrasound using fluoroscopy procedures for the investigation of PPL performed by experienced bronchoscopists with no specific previous training in this particular technique. Operator learning curves and radiological predictors were assessed for all consecutive patients examined during the first year of application of the technique. Fifty-one PPL were investigated. Diagnostic yield and visualization yield were 72.5 and 82.3% respectively. The diagnostic yield was 64.0% for PPL ≤20mm, and 80.8% for PPL>20mm. No false-positive results were recorded. The learning curve of all diagnostic tools showed a DY of 72.7% for the first sub-group of patients, 81.8% for the second, 72.7% for the third, and 81.8% for the last. Bronchoscopy with radial probe endobronchial ultrasound using fluoroscopy as guidance is safe and simple to perform, even without specific prior training, and diagnostic yield is high for PPL>and ≤20mm. Based on these findings, this method could be introduced as a first-line procedure for the investigation of PPL, particularly in centers with limited resources. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

  6. Calculation of patient effective dose and scattered dose for dental mobile fluoroscopic equipment: application of the Monte Carlo simulation.

    Lee, Boram; Lee, Jungseok; Kang, Sangwon; Cho, Hyelim; Shin, Gwisoon; Lee, Jeong-Woo; Choi, Jonghak


    The objective of this study was to evaluate the patient effective dose and scattered dose from recently developed dental mobile equipment in Korea. The MCNPX 2.6 (Los Alamos National Laboratory, USA) was used in a Monte Carlo simulation to calculate both the effective and scattered doses. The MCNPX code was constructed identically as in the general use of equipment and the effective dose and scattered dose were calculated using the KTMAN-2 digital phantom. The effective dose was calculated as 906 μSv. The equivalent doses per organ were calculated via the MCNPX code, and were 32 174 and 19 μSv in the salivary gland and oesophagus, respectively. The scattered dose of 22.5-32.6 μSv of the tube side at 25 cm from the centre in anterior and posterior planes was measured as 1.4-3 times higher than the detector side of 10.5-16.0 μSv.

  7. High knee valgus in female subjects does not yield higher knee translations during drop landings: a biplane fluoroscopic study.

    Torry, Michael R; Shelburne, Kevin B; Myers, Casey; Giphart, J Erik; Pennington, W Wesley; Krong, Jacob P; Peterson, Daniel S; Steadman, J Richard; Woo, Savio L-Y


    The goal of this study was to determine the effects of peak knee valgus angle and peak knee abductor moment on the anterior, medial, and lateral tibial translations (ATT, MTT, LTT) in the "at risk" female knee during drop landing. Fifteen female subjects performed drop landings from 40 cm. Three-dimension knee motion was simultaneously recorded using a high speed, biplane fluoroscopy system, and a video-based motion analysis system. Valgus knee angles and knee abduction moments were stratified into low, intermediate, and high groups and peak ATT, MTT, and LTT were compared between these groups with ANOVA (α = 0.05). Significant differences were observed between stratified groups in peak knee valgus angle (p < 0.0001) and peak knee abduction moment (p < 0.0001). However, no corresponding differences in peak ATT, LTT, and MTT between groups exhibiting low to high-peak knee valgus angles (ATT: p = 0.80; LTT: p = 0.25; MTT: p = 0.72); or, in peak ATT (p = 0.61), LTT (p = 0.26) and MTT (p = 0.96) translations when stratified according to low to high knee abduction moments, were found. We conclude that the healthy female knee is tightly regulated with regard to translations even when motion analysis derived knee valgus angles and abduction moments are high.

  8. Reference air kerma and kerma-area product as estimators of peak skin dose for fluoroscopically guided interventions

    Kwon, Deukwoo; Little, Mark P.; Miller, Donald L. [Radiation Epidemiology Branch, National Cancer Institute, Division of Cancer Epidemiology and Genetics, Bethesda, Maryland 20852-7238 (United States); Radiation Epidemiology Branch, National Cancer Institute, Division of Cancer Epidemiology and Genetics, Bethesda, Maryland 20852-7238 and Department of Radiology and Radiological Sciences, F. Edward Hebert School of Medicine, Uniformed Services University, Bethesda, Maryland 20814 (United States)


    Purpose: To determine more accurate regression formulas for estimating peak skin dose (PSD) from reference air kerma (RAK) or kerma-area product (KAP). Methods: After grouping of the data from 21 procedures into 13 clinically similar groups, assessments were made of optimal clustering using the Bayesian information criterion to obtain the optimal linear regressions of (log-transformed) PSD vs RAK, PSD vs KAP, and PSD vs RAK and KAP. Results: Three clusters of clinical groups were optimal in regression of PSD vs RAK, seven clusters of clinical groups were optimal in regression of PSD vs KAP, and six clusters of clinical groups were optimal in regression of PSD vs RAK and KAP. Prediction of PSD using both RAK and KAP is significantly better than prediction of PSD with either RAK or KAP alone. The regression of PSD vs RAK provided better predictions of PSD than the regression of PSD vs KAP. The partial-pooling (clustered) method yields smaller mean squared errors compared with the complete-pooling method.Conclusion: PSD distributions for interventional radiology procedures are log-normal. Estimates of PSD derived from RAK and KAP jointly are most accurate, followed closely by estimates derived from RAK alone. Estimates of PSD derived from KAP alone are the least accurate. Using a stochastic search approach, it is possible to cluster together certain dissimilar types of procedures to minimize the total error sum of squares.

  9. High Knee Valgus in Female Subjects Does Not Yield Higher Knee Translations During Drop Landings: A Biplane Fluoroscopic Study

    Torry, Michael R.; Shelburne, Kevin B.; Myers, Casey; Giphart, J. Erik; Pennington, W. Wesley; Krong, Jacob P.; Peterson, Daniel S.; Steadman, J. Richard; Woo, Savio L-Y.


    The goal of this study was to determine the effects of peak knee valgus angle and peak knee abductor moment on the anterior, medial, and lateral tibial translations (ATT, MTT, LTT) in the ‘at risk’ female knee during drop landing. Fifteen female subjects performed drop landings from 40 cm. 3D knee motion was simultaneously recorded using a high speed, biplane fluoroscopy system and a video-based motion analysis system. Valgus knee angles and knee abduction moments were stratified into low, intermediate and high groups and peak ATT, MTT and LTT were compared between these groups with ANOVA (α = .05). Significant differences were observed between stratified groups in peak knee valgus angle (p knee abduction moment (p knee valgus angles (ATT: p = .80; LTT: p = .25; MTT: p = .72); or, in peak ATT (p = .61), LTT (p = .26) and MTT (p = .96) translations when stratified according to low to high knee abduction moments, were found. We conclude that the healthy female knee is tightly regulated with regard to translations even when motion analysis derived knee valgus angles and abduction moments are high. PMID:22968826

  10. Fluoroscopic caudal epidural injections in managing chronic axial low back pain without disc herniation, radiculitis, or facet joint pain

    Manchikanti L


    Full Text Available Laxmaiah Manchikanti,1,2 Kimberly A Cash,1 Carla D McManus,1 Vidyasagar Pampati11Pain Management Center of Paducah, Paducah, 2Department of Anesthesiology and Perioperative Medicine, University of Louisville, Louisville, KY, USABackground: Chronic low back pain without disc herniation is common. Various modalities of treatments are utilized in managing this condition, including epidural injections. However, there is continued debate on the effectiveness, indications, and medical necessity of any treatment modality utilized for managing axial or discogenic pain, including epidural injections.Methods: A randomized, double-blind, actively controlled trial was conducted. The objective was to evaluate the ability to assess the effectiveness of caudal epidural injections of local anesthetic with or without steroids for managing chronic low back pain not caused by disc herniation, radiculitis, facet joints, or sacroiliac joints. A total of 120 patients were randomized to two groups; one group did not receive steroids (group 1 and the other group did (group 2. There were 60 patients in each group. The primary outcome measure was at least 50% improvement in Numeric Rating Scale and Oswestry Disability Index. Secondary outcome measures were employment status and opioid intake. These measures were assessed at 3, 6, 12, 18, and 24 months after treatment.Results: Significant pain relief and functional status improvement (primary outcome defined as a 50% or more reduction in scores from baseline, were observed in 54% of patients in group 1 and 60% of patients in group 2 at 24 months. In contrast, 84% of patients in group 1 and 73% in group 2 saw significant pain relief and functional status improvement in the successful groups at 24 months.Conclusion: Caudal epidural injections of local anesthetic with or without steroids are effective in patients with chronic axial low back pain of discogenic origin without facet joint pain, disc herniation, and/or radiculitis.Keywords: chronic axial low back pain, discogenic pain, disc herniation, caudal epidural injections

  11. Evaluation of flow with dynamic x-ray imaging for aneurysms

    Dohatcu, Andreea Cristina

    characteristics as a result of interaction with an AVS. A comparison with optical-dye-dilution data and 3D Computational Fluid Dynamics virtual angiography (CFD) data in similar conditions was also performed. Task oriented optimization of x-ray system parameters with regard to the needs of obtaining TDCs so as to obtain more accurate information of contrast media flow into aneurysms from angiographic images, were done. This includes a comparison between a commercial x-ray Flat Panel Detector (FPD) and an in-house new x-ray micro detector prototype, the Micro-Angiographic Fluoroscope (MAF). X-ray dose levels given in clinical procedures similar in length and complexity to aneurysm treatments, were studied on a statistical representative batch. It was concluded that there is a need for reduction of radiation-induced skin injuries to patients following interventional procedures. Hence, we developed and assessed a method to evaluate the variation of image quality (which impacts the success of TDC analysis) and dose with the acquisition mode operation logic and the automatic-brightness-control (ABC); this method was applied to two clinical interventional fluoroscopic imaging systems: one with an Image Intensifier (II) and the other with a Flat Panel Detector (FPD). The resultant ABC tracking curves obtained for the various imaging modes available on a given system can then be used for proper selection of technique to achieve the needed contrast signal to noise ratio to acquire adequate data for TDC evaluation, while controlling the patient dose.

  12. Complications of Fluoroscopically Guided Percutaneous Gastrostomy With Large-bore Balloon-retained Catheter in Patients With Head and Neck Tumors

    Siu-Cheung Chan


    Conclusion: FPG is a safe method with low mortality and complication rate for constructing long-term enteral access in patients with head and neck cancer and esophageal abnormalities, who have no endoscopic access to the stomach.

  13. Use of a graphics processing unit (GPU) to facilitate real-time 3D graphic presentation of the patient skin-dose distribution during fluoroscopic interventional procedures.

    Rana, Vijay; Rudin, Stephen; Bednarek, Daniel R


    We have developed a dose-tracking system (DTS) that calculates the radiation dose to the patient's skin in real-time by acquiring exposure parameters and imaging-system-geometry from the digital bus on a Toshiba Infinix C-arm unit. The cumulative dose values are then displayed as a color map on an OpenGL-based 3D graphic of the patient for immediate feedback to the interventionalist. Determination of those elements on the surface of the patient 3D-graphic that intersect the beam and calculation of the dose for these elements in real time demands fast computation. Reducing the size of the elements results in more computation load on the computer processor and therefore a tradeoff occurs between the resolution of the patient graphic and the real-time performance of the DTS. The speed of the DTS for calculating dose to the skin is limited by the central processing unit (CPU) and can be improved by using the parallel processing power of a graphics processing unit (GPU). Here, we compare the performance speed of GPU-based DTS software to that of the current CPU-based software as a function of the resolution of the patient graphics. Results show a tremendous improvement in speed using the GPU. While an increase in the spatial resolution of the patient graphics resulted in slowing down the computational speed of the DTS on the CPU, the speed of the GPU-based DTS was hardly affected. This GPU-based DTS can be a powerful tool for providing accurate, real-time feedback about patient skin-dose to physicians while performing interventional procedures.

  14. Fluoroscopic cervical epidural injections in chronic axial or disc-related neck pain without disc herniation, facet joint pain, or radiculitis

    Manchikanti L


    Full Text Available Laxmaiah Manchikanti, Kimberly A Cash, Vidyasagar Pampati, Yogesh MallaPain Management Center of Paducah, Paducah, KY, USABackground: While chronic neck pain is a common problem in the adult population, with a typical 12-month prevalence of 30%–50%, there is a lack of consensus regarding its causes and treatment. Despite limited evidence, cervical epidural injections are one of the commonly performed nonsurgical interventions in the management of chronic neck pain.Methods: A randomized, double-blind, active, controlled trial was conducted to evaluate the effectiveness of cervical interlaminar epidural injections of local anesthetic with or without steroids for the management of chronic neck pain with or without upper extremity pain in patients without disc herniation, radiculitis, or facet joint pain.Results: One hundred and twenty patients without disc herniation or radiculitis and negative for facet joint pain by means of controlled diagnostic medial branch blocks were randomly assigned to one of two treatment groups, ie, injection of local anesthetic only (group 1 or local anesthetic mixed with nonparticulate betamethasone (group 2. The primary outcome of significant pain relief and improvement in functional status (≥50% was demonstrated in 72% of group 1 and 68% of group 2. The overall average number of procedures per year was 3.6 in both groups with an average total relief per year of 37–39 weeks in the successful group over a period of 52 weeks.Conclusion: Cervical interlaminar epidural injections of local anesthetic with or without steroids may be effective in patients with chronic function-limiting discogenic or axial pain.Keywords: chronic neck pain, cervical disc herniation, cervical discogenic pain, cervical epidural injections, epidural steroids, local anesthetics

  15. Use of a graphics processing unit (GPU) to facilitate real-time 3D graphic presentation of the patient skin-dose distribution during fluoroscopic interventional procedures

    Rana, Vijay; Rudin, Stephen; Bednarek, Daniel R.


    We have developed a dose-tracking system (DTS) that calculates the radiation dose to the patient's skin in realtime by acquiring exposure parameters and imaging-system-geometry from the digital bus on a Toshiba Infinix C-arm unit. The cumulative dose values are then displayed as a color map on an OpenGL-based 3D graphic of the patient for immediate feedback to the interventionalist. Determination of those elements on the surface of the patient 3D-graphic that intersect the beam and calculation of the dose for these elements in real time demands fast computation. Reducing the size of the elements results in more computation load on the computer processor and therefore a tradeoff occurs between the resolution of the patient graphic and the real-time performance of the DTS. The speed of the DTS for calculating dose to the skin is limited by the central processing unit (CPU) and can be improved by using the parallel processing power of a graphics processing unit (GPU). Here, we compare the performance speed of GPU-based DTS software to that of the current CPU-based software as a function of the resolution of the patient graphics. Results show a tremendous improvement in speed using the GPU. While an increase in the spatial resolution of the patient graphics resulted in slowing down the computational speed of the DTS on the CPU, the speed of the GPU-based DTS was hardly affected. This GPU-based DTS can be a powerful tool for providing accurate, real-time feedback about patient skin-dose to physicians while performing interventional procedures.

  16. Significance of including field non-uniformities such as the heel effect and beam scatter in the determination of the skin dose distribution during interventional fluoroscopic procedures

    Rana, Vijay; Gill, Kamaljit; Rudin, Stephen; Bednarek, Daniel R.


    The current version of the real-time skin-dose-tracking system (DTS) we have developed assumes the exposure is contained within the collimated beam and is uniform except for inverse-square variation. This study investigates the significance of factors that contribute to beam non-uniformity such as the heel effect and backscatter from the patient to areas of the skin inside and outside the collimated beam. Dose-calibrated Gafchromic film (XR-RV3, ISP) was placed in the beam in the plane of the patient table at a position 15 cm tube-side of isocenter on a Toshiba Infinix C-Arm system. Separate exposures were made with the film in contact with a block of 20-cm solid water providing backscatter and with the film suspended in air without backscatter, both with and without the table in the beam. The film was scanned to obtain dose profiles and comparison of the profiles for the various conditions allowed a determination of field non-uniformity and backscatter contribution. With the solid-water phantom and with the collimator opened completely for the 20-cm mode, the dose profile decreased by about 40% on the anode side of the field. Backscatter falloff at the beam edge was about 10% from the center and extra-beam backscatter decreased slowly with distance from the field, being about 3% of the beam maximum at 6 cm from the edge. Determination of the magnitude of these factors will allow them to be included in the skin-dose-distribution calculation and should provide a more accurate determination of peak-skin dose for the DTS.

  17. Dose reduction technique using a combination of a region of interest (ROI) material x-ray attenuator and spatially different temporal filtering for fluoroscopic interventions

    Swetadri Vasan, S. N.; Panse, A.; Jain, A.; Sharma, P.; Ionita, Ciprian N.; Titus, A. H.; Cartwright, A. N.; Bednarek, D. R.; Rudin, S.


    We demonstrate a novel approach for achieving patient dose savings during image-guided neurovascular interventions, involving a combination of a material x-ray region of interest (ROI) attenuator and a spatially different ROI temporal filtering technique. The part of the image under the attenuator is reduced in dose but noisy and less bright due to fewer x-ray quanta reaching the detector, as compared to the non-attenuating (or less attenuating) region. First the brightness is equalized throughout the image by post processing and then a temporal filter with higher weights is applied to the high attenuating region to reduce the noise, at the cost of increased lag; however, in the regions where less attenuation is present, a lower temporal weight is needed and is applied to preserve temporal resolution. A simulation of the technique is first presented on an actual image sequence obtained from an endovascular image guided interventional (EIGI) procedure. Then the actual implementation of the technique with a physical ROI attenuator is presented. Quantitative analysis including noise analysis and integral dose calculations are presented to validate the proposed technique.

  18. Development and evaluation of a new radiographic and fluoroscopic imager based on electron-multiplying CCDs: The solid state x-ray image intensifier

    Kuhls-Gilcrist, Andrew Thomas

    A new dual detector system was developed which utilizes a low resolution, large field-of-view x-ray image intensifier (II) and a high resolution, region-of-interest microangiographic (MA) detector on the same c-arm gantry. With this new MA-II system, the larger field-of-view (FOV) II can be operated when the demands of the task are not as high, and a larger imaging area is desired. However, when a higher-resolution image with greater image quality is desired at a targeted region-of-interest (ROI), the MA can be deployed to take on these greater demands. To quantitatively and qualitatively assess the imaging performance of each detector under realistic conditions, angiographic images of simulated vessels and rabbit neurovasculature were acquired with both detectors under nearly identical conditions. With the MA detector deployed, vessels as small as 95 mum were visible, whereas the II could not detect vessels smaller than 235 mum. The ROI MA mode was also shown to provide sharper images with higher contrast-to-noise ratios and was four times as likely to successfully detect overlapping vessels as compared to the II. More accurate three-dimensional center lines of vasculature using multi-view reconstruction techniques were also obtained with the MA. The solid state x-ray image intensifier (SSXII) was developed to provide similar high-resolution imaging capabilities as the MA and a built in adjustable gain to provide high-sensitivity imaging capabilities for operation at all exposures used in medical x-ray imaging procedures. The imaging components used in construction of the prototype SSXII were selected based on a theoretical performance evaluation, using a Fourier-based linear-systems model analysis. The performance of the prototype SSXII was then extensively evaluated. Images of various objects and image comparisons with current state-of-the-art detectors qualitatively demonstrated that the SSXII is capable of providing substantial improvements. A quantitative assessment of spatial resolution, noise performance, and overall performance was then determined using MTF, INEE, and DQE measurements. In addition to the overall performance of the SSXII, the performances of individual components were determined using measurements of their resolution and transmission efficiency. The unique ability of the SSXII to operate in both tradition energy integrating (EI) mode and single photon counting (SPC) mode was also demonstrated. To better assess detector performance, a new method for determination of the two-dimensional presampled MTF, the "noise-response method", was developed and evaluated. Compared to current measurement methods, the noise-response method simplifies the MTF determination by eliminating the need for manufacture and alignment of precisely machined test objects, thereby eliminating inaccuracies that result from the use of such objects and subsequent analysis of the resulting images. The accuracy of this method was demonstrated using both simulated and experimental data sets. For the simulated image set which used a simple detector model for which the "true" MTF was known exactly, excellent agreement was obtained with the MTF determined using the noise-response method, with a maximum deviation of 1.1%. Comparison measurements were also made on this simulated data set with the established edge-response method and these showed deviations greater than 35% from the "true" MTF. Experimental measurements on a range of detector technologies (including an XII, FPD and SSXII) demonstrated agreement between the noise-response and edge-response methods within experimental uncertainty, with discrepancies likely resulting from errors inherent in the edge-response MTF procedure. The two-dimensional MTF for the FPD was non-isotropic, with an increase observed on the diagonals, whereas the SSXII MTF was shown to be largely symmetric. Initial results indicate that the new noise-response method is a promising candidate to replace existing standard methods. To further assess detector performance, the instrumentation noise equivalent exposure (INEE) metric has been developed to address the need for a direct, quantitative measure of the quantum-noise-limited exposure range of x-ray detectors by providing the threshold exposure at which the detector instrumentation-noise exceeds the quantum-noise. Frequency dependence and all instrumentation noise sources were investigated to provide a greater understanding of this promising new metric and to ensure quantum noise limited operation at every spatial frequency of interest. Measurements were done on various x-ray detectors to demonstrate the usefulness of these new developments. In addition to providing a practical quantification of instrumentation noise, the INEE was also shown to provide insight into overall detector performance in terms of the behavior of the DQE as a function of exposure. (Abstract shortened by UMI.)

  19. Stenosis in laparoscopic gastric bypass: management by endoscopic dilation without fluoroscopic guidance Estenosis tras derivación gástrica laparoscópica: tratamiento mediante dilataciones endoscópicas sin control radiológico

    Jesús Espinel


    Full Text Available Objectives: gastric bypass is the surgical procedure that is carried out most frequently in the treatment of morbid obesity. Stenosis of the gastro-jejunal anastomosis is a relatively frequent complication that requires endoscopic management. However, the optimal dilation technique is yet to be determined. The purpose of this study was to evaluate the safety and efficacy of dilation with a hydrostatic balloon (CRE without radioscopic guidance in morbidly obese patients treated by laparoscopic bypass. Material and methods: retrospective review of the data elicited from 525 patients treated against morbid obesity with laparoscopic gastric bypass from January, 2006 to November, 2010. Results: a total of 22/525 patients (4.1% developed stenosis of the anastomosis [20 women (91%, 2 men (9%]. In four patients (18.2%, there was an associated anastomotic ulcer, and in one case, there was a history of bleeding of an ulcer treated with sclerosis one month earlier. The diagnosis of stenosis was done in most patients during the first 90 days after the bypass. All cases were resolved by means of endoscopic dilation without radioscopic guidance, 15 cases (68.1% required a single session, 6 cases (27.2% two sessions, and 1 case (4.5% required four sessions. This last case had an associated anastomotic ulcer. The diameter of the balloons ranged from 12 to 20 mm, generally using diameters of 12-15 mm in the first session, and increasing them in the following sessions according to the previous result. One patient treated with a 20 mm balloon presented with a small tear, without showing any evidence of leak of contrast medium in the radioscopic guidance, and was thus managed conservatively. In the follow-up, no re-stenoses were detected. Conclusions: in our experience, stenosis of the anastomosis in the laparoscopic gastric bypass is an infrequent complication. When it happens, dilation with a hydrostatic balloon is an effective and safe treatment. Radioscopic guidance during dilation is not strictly necessary if norms of progressive dilation are followed.

  20. Evaluation

    Ayman Galhom


    Conclusions: Fluoroscopic guided injection and surgery have the highest efficacy and satisfaction rates in managing chronic coccygodynia. Hypermobility and spicules are predictors of failure of conservative therapy.

  1. Application of a Fast Connected Components Labeling Algorithm in Processing Landmark Images


    Extracting geometric data of landmarks from fluoroscopic images plays an important role in camera calibration process of a fluoroscopic-image-based surgical navigation system. Connected components labeling is the essential technique for the extraction. A new fast connected components labeling algorithm was presented. The definition of upward concave set was introduced to explain the algorithm. Feasibility and efficiency of the algorithm were verified with experiments. This algorithm performs well in labeling non-upward concave set connected components and applies to landmarks labeling well. Moreover, the proposed algorithm possesses a desirable characteristic that will facilitate the subsequent processing of fluoroscopic images.

  2. Missing Broken Needle During Caesarean Section

    Chandana Das


    Full Text Available Breakage of the needle and missing while repairing the uterine wound during cesarean section is an uncommon event. Subsequently it was removed under fluoroscopic guidance on the 7th postoperative day

  3. 75 FR 54493 - Cardiovascular Devices; Reclassification of Certain Percutaneous Transluminal Coronary...


    ... facilitate fluoroscopic visualization of the balloon during use. A PTCA catheter is intended for balloon... visualization of the balloon during use. A PTCA catheter is intended for balloon dilatation of a hemodynamically.... BILLING CODE 4160-01-S...

  4. Lumbar pedicle screw placement: Using only AP plane imaging

    Anil Sethi


    Conclusion: Placement of pedicle screws under fluoroscopic guidance using AP plane imaging alone with tactile guidance is safe, fast, and reliable. However, a good understanding of the radiographic landmarks is a prerequisite.

  5. Transnasal tracheobronchial stenting for malignant airway narrowing under local anesthesia: Our experience of treating three cases using this technique

    Jayanta Medhi


    Full Text Available Purpose: To study the technical feasibility of tracheobronchial stenting via transnasal route under bronchoscopy and fluoroscopic guidance in severe malignant airway strictures using self-expandable nitinol stents. Materials and Methods: We describe three patients with malignant airway strictures, treated entirely via transnasal route under local anesthesia using bronchoscopic and fluoroscopic guidance. Nasal route allowed convenient access to the airway for the bronchoscope across the stricture and a guidewire was introduced through its working channel. The 18F tracheal stent and the 6F bronchial stent assembly could be easily introduced and deployed under bronchoscopic (reintroduced through the other nostril and fluoroscopic guidance. Results: We achieved technical success in all the three patients with immediate relief of dyspnea. Conclusion: Transnasal airway stenting with self-expandable nitinol stent using bronchoscopic and fluoroscopic guidance under local anesthesia is a safe and effective method with minimal patient discomfort.

  6. Arthrography

    Full Text Available ... may be required prior to sedation. You should plan to have a relative or friend drive you ... Image Gallery Musculoskeletal radiologist using fluoroscopic images to plan an ankle arthrogram. View full size with caption ...

  7. Tracking the path traversed by temporary pacing lead

    Kapoor, Aditya; Moorthy, Nagaraja; Khanna, Roopali; Kumar, Sudeep


    ... of stylets and considerable lead maneuvering. We describe an interesting case wherein a temporary pacemaker lead after entering the PLSVC followed an unusual fluoroscopic course with demonstrable pacing in right ventricle (RV), right atrium (RA...

  8. A study of the x-ray image quality improvement in the examination of the respiratory system based on the new image processing technique

    Nagai, Yuichi; Kitagawa, Mayumi; Torii, Jun; Iwase, Takumi; Aso, Tomohiko; Ihara, Kanyu; Fujikawa, Mari; Takeuchi, Yumiko; Suzuki, Katsumi; Ishiguro, Takashi; Hara, Akio


    Recently, the double contrast technique in a gastrointestinal examination and the transbronchial lung biopsy in an examination for the respiratory system [1-3] have made a remarkable progress. Especially in the transbronchial lung biopsy, better quality of x-ray fluoroscopic images is requested because this examination is performed under a guidance of x-ray fluoroscopic images. On the other hand, various image processing methods [4] for x-ray fluoroscopic images have been developed as an x-ray system with a flat panel detector [5-7] is widely used. A recursive filtering is an effective method to reduce a random noise in x-ray fluoroscopic images. However it has a limitation for its effectiveness of a noise reduction in case of a moving object exists in x-ray fluoroscopic images because the recursive filtering is a noise reduction method by adding last few images. After recursive filtering a residual signal was produced if a moving object existed in x-ray images, and this residual signal disturbed a smooth procedure of the examinations. To improve this situation, new noise reduction method has been developed. The Adaptive Noise Reduction [ANR] is the brand-new noise reduction technique which can be reduced only a noise regardless of the moving object in x-ray fluoroscopic images. Therefore the ANR is a very suitable noise reduction method for the transbronchial lung biopsy under a guidance of x-ray fluoroscopic images because the residual signal caused of the moving object in x-ray fluoroscopic images is never produced after the ANR. In this paper, we will explain an advantage of the ANR by comparing of a performance between the ANR images and the conventional recursive filtering images.

  9. X-ray fluoroscopy noise modeling for filter design.

    Cesarelli, M; Bifulco, P; Cerciello, T; Romano, M; Paura, L


    Fluoroscopy is an invaluable tool in various medical practices such as catheterization or image-guided surgery. Patient's screen for prolonged time requires substantial reduction in X-ray exposure: The limited number of photons generates relevant quantum noise. Denoising is essential to enhance fluoroscopic image quality and can be considerably improved by considering the peculiar noise characteristics. This study presents analytical models of fluoroscopic noise to express the variance of noise as a function of gray level, a practical method to estimate the parameters of the models and a possible application to improve the performance of noise filtering. Quantum noise is modeled as a Poisson distribution and results strongly signal-dependent. However, fluoroscopic devices generally apply gray-level transformations (i.e., logarithmic-mapping, gamma-correction) for image enhancement. The resulting statistical transformations of the noise were analytically derived. In addition, a characterization of the statistics of noise for fluoroscopic image differences was offered by resorting to Skellam distribution. Real fluoroscopic sequences of a simple step-phantom were acquired by a conventional fluoroscopic device and were utilized as actual noise measurements to compare with. An adaptive spatio-temporal filter based on the local conditional average of similar pixels has been proposed. The gray-level differences between the local pixel and the neighboring pixels have been assumed as measure of similarity. Filter performance was evaluated by using real fluoroscopic images of a step phantom and acquired during a pacemaker implantation. The comparison between experimental data and the analytical derivation of the relationship between noise variance and mean pixel intensity (noise-parameter models) were presented relatively to raw-images, after applying logarithmic-mapping or gamma-correction and for difference images. Results have confirmed a great agreement (adjusted R

  10. Acquisition of quantitative physiological data and computerized image reconstruction using a single scan TV system

    Baily, N. A.


    A single-scan radiography system has been interfaced to a minicomputer, and the combined system has been used with a variety of fluoroscopic systems and image intensifiers available in clinical facilities. The system's response range is analyzed, and several applications are described. These include determination of the gray scale for typical X-ray-fluoroscopic-television chains, measurement of gallstone volume in patients, localization of markers or other small anatomical features, determinations of organ areas and volumes, computer reconstruction of tomographic sections of organs in motion, and computer reconstruction of transverse axial body sections from fluoroscopic images. It is concluded that this type of system combined with a minimum of statistical processing shows excellent capabilities for delineating small changes in differential X-ray attenuation.

  11. Wrist arthrography: a simple method

    Berna-Serna, Juan D.; Reus, Manuel; Alonso, Jose [Virgen de la Arrixaca University Hospital, Department of Radiology, El Palmar (Murcia) (Spain); Martinez, Francisco; Domenech-Ratto, Gines [University of Murcia, Department of Human Anatomy, Faculty of Medicine, Murcia (Spain)


    A technique of wrist arthrography is presented using an adhesive marker-plate with radiopaque coordinates to identify precisely sites for puncture arthrography of the wrist and to obviate the need for fluoroscopic guidance. Radiocarpal joint arthrography was performed successfully in all 24 cases, 14 in the cadaveric wrists and 10 in the live patients. The arthrographic procedure described in this study is simple, safe, and rapid, and has the advantage of precise localisation of the site for puncture without need for fluoroscopic guidance. (orig.)

  12. Performing a Better Bone Marrow Aspiration.

    Friedlis, Mayo F; Centeno, Christopher J


    Bone marrow aspiration (BMA) is increasingly being used to harvest stem cells for use in regenerative medicine. The focus of BMA in interventional orthopedics is to maximize the yield of mesenchymal stem cells. The authors present an improved method for BMA that involves fluoroscope or ultrasound guidance combined with anesthesia; in the authors' experience, it produces the highest possible stem cell yield and is well tolerated by patients. The authors provide a step-by-step guide to the process, along with a discussion of technical and other considerations and quick reference guides for ultrasound- and fluoroscope-guided BMA. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. 21 CFR 1020.30 - Diagnostic x-ray systems and their major components.


    ... imaging assembly means a subsystem in which x-ray photons produce a set of fluoroscopic images or... scan. Solid state x-ray imaging device means an assembly, typically in a rectangular panel... aluminum equivalent of each filter. (5) Imaging system information. For x-ray systems manufactured on or...

  14. Fluoroscopy-guided snare retrieval of the celt ACD(®) metallic vascular closure device following failed deployment.

    Cahill, Thomas J; Choji, Kiyoshi; Kardos, Attila


    We report a case of endovascular snare retrieval of a new stainless steel vascular closure device (Celt ACD(®) , Kimal, Middlesex, UK) from the common femoral artery, following device failure after diagnostic coronary angiography. The stainless steel composition of the device aided successful fluoroscopic localization and removal.

  15. The lung volume reduction coil for the treatment of emphysema : a new therapy in development

    Klooster, Karin; ten Hacken, Nick H. T.; Slebos, Dirk-Jan


    Lung volume reduction (LVR) coil treatment is a novel therapy for patients with severe emphysema. In this bilateral bronchoscopic treatment, approximately 10 LVR coils per lobe are delivered under fluoroscopic guidance in two sequential procedures. The LVR coil reduces lung volume by compressing the

  16. Statistical shape model-based femur kinematics from biplane fluoroscopy

    Baka, N.; de Bruijne, Marleen; Walsum, T. van


    on the distal femur using eight biplane fluoroscopic drop-landing sequences. The proposed dynamic prior and features increased the convergence rate of the reconstruction from 71% to 91%, using a convergence limit of 3 mm. The achieved root mean square point-to-surface accuracy at the converged frames was 1...

  17. 2D-3D shape reconstruction of the distal femur from stereo X-Ray imaging using statistical shape models

    Baka, N.; Kaptein, B. L.; de Bruijne, Marleen


    pose estimation of ground truth shapes as well as 3D shape estimation using a SSM of the whole femur, from stereo cadaver X-rays, in vivo biplane fluoroscopy image-pairs, and an in vivo biplane fluoroscopic sequence. Ground truth shapes for all experiments were available in the form of CT segmentations...

  18. The use of virtual reality for training in carotid artery stenting: a construct validation study

    Berry, M.; Reznick, R.; Lystig, T.


    of subjective parameters using a visual analog scale. Results: Procedure and fluoroscopic time was 8.7 and 8.7 min greater in the novice group (P=0.0066 and P=0.0031), respectively. There were no significant differences in performances between the two groups in the remaining metrics of cine loops (number...

  19. Arthrography

    Full Text Available ... E-mail: Area code: Phone no: Thank you! Images × Image Gallery Musculoskeletal radiologist using fluoroscopic images to plan ... address): From (your name): Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your ...

  20. A simple technique to remove migrated esophageal stents.

    Noyer, C M; Forohar, F


    A 51-yr-old man with a tracheoesophageal fistula from an esophageal carcinoma had two expandable covered stents placed, which migrated distally. After several unsuccessful attempts to remove the stents, we fashioned a homemade snare to entrap and remove the stents under endoscopic and fluoroscopic guidance.

  1. Radiographer involvement with stent insertion to palliate symptomatic dysphagia resulting from neoplastic obstruction

    Law, R.L. [Department of Radiology, Frenchay Hospital, Bristol, BS16 1LE (United Kingdom)], E-mail:


    Self-expanding metal stent (SEMS) insertion is recognized as an effective palliative treatment for patients with symptomatic dysphagia resulting from inoperable neoplastic occlusion. This paper reviews radiographer involvement in the fluoroscopic deployment of SEMS. One hundred and fifty-eight SEMS were passed in 136 consecutive patients. Radiographers were responsible for the barium swallow and subsequent passage of an oro-gastric wire across the strictured lumen. One hundred and twenty-seven guide wire insertions under fluoroscopic control transgressed the tumour lumen at first attempt. Nine (6.6%) guide wire insertions were unsuccessful at first attempt however two patients (2.7%) had successful second attempts at fluoroscopically guided wire insertion. Five patients went on to have a joint endoscopic/fluoroscopic SEMS procedure, three were successful, two failed. Due to poor health it was decided not to proceed with further intervention with two other patients. With an overall success rate of 96%, a joint radiographer/clinician approach to guide wire insertion and subsequent SEMS deployment using fluoroscopy alone is a safe, time- and cost-effective procedure.

  2. Combined pre-injection wrist and ankle MRI protocol and steroid joint injections in juvenile idiopathic arthritis

    Kan, J.H. [Texas Children' s Hospital, Department of Radiology, Houston, TX (United States); Graham, T.B. [Monroe Carell Jr. Children' s Hospital at Vanderbilt, Department of Pediatric Rheumatology, Nashville, TN (United States)


    Precise localization of affected compartments of the wrist and ankle in children with an established diagnosis of juvenile idiopathic arthritis (JIA) is clinically challenging. The purpose of this paper is to describe our experience utilizing a pre-injection MRI protocol of the wrist and ankle for localizing disease activity followed by fluoroscopically guided joint injections in children with JIA. (orig.)

  3. Reduction of CT beam hardening artefacts of ethylene vinyl alcohol copolymer by variation of the tantalum content: evaluation in a standardized aortic endoleak phantom

    Treitl, Karla M.; Scherr, Michael; Foerth, Monika; Braun, Franziska; Maxien, Daniel; Treitl, Marcus [Hospitals of the Ludwig-Maximilians-University of Munich, Institute for Clinical Radiology, Munich (Germany)


    Our aim was to develop an aortic stent graft phantom to simulate endoleak treatment and to find a tantalum content (TC) of ethylene-vinyl-alcohol-copolymer that causes fewer computed tomography (CT) beam hardening artefacts, but still allows for fluoroscopic visualization. Ethylene-vinyl-alcohol-copolymer specimens of different TC (10-50 %, and 100 %) were injected in an aortic phantom bearing a stent graft and endoleak cavities with simulated re-perfusion. Fluoroscopic visibility of the ethylene-vinyl-alcohol-copolymer specimens was analyzed. In addition, six radiologists analyzed endoleak visibility, and artefact intensity of ethylene-vinyl-alcohol-copolymer in CT. Reduction of TC significantly decreased CT artefact intensity of ethylene-vinyl-alcohol-copolymer and increased visibility of endoleak re-perfusion (p < 0.000). It also significantly decreased fluoroscopic visibility of ethylene-vinyl-alcohol-copolymer (R = 0.883, p ≤ 0.01), and increased the active embolic volumes prior to visualization (Δ ≥ 40 μl). Ethylene-vinyl-alcohol-copolymer specimens with a TC of 45-50 % exhibited reasonable visibility, a low active embolic volume and a tolerable CT artefact intensity. The developed aortic stent graft phantom allows for a reproducible simulation of embolization of endoleaks. The data suggest a reduction of the TC of ethylene-vinyl-alcohol-copolymer to 45 -50 % of the original, to interfere less with diagnostic imaging in follow-up CT examinations, while still allowing for fluoroscopic visualization. (orig.)

  4. Interventional radiology in the lacrimal drainage system

    Ilgit, Erhan T. [Department of Radiology, School of Medicine, Gazi University, Besevler 06510, Ankara (Turkey)]. E-mail:; Oenal, Baran [Department of Radiology, School of Medicine, Gazi University, Besevler 06510, Ankara (Turkey); Coskun, Bilgen [Department of Radiology, School of Medicine, Gazi University, Besevler 06510, Ankara (Turkey)


    This article presents a review of the interventional radiological procedures in the lacrimal drainage system. Balloon dacryocystoplasty and nasolacrimal polyurethane stent placement are the main fluoroscopically guided interventions for the treatment of epiphora by recanalizing the obstructed LDS. These procedures can also be used for dacryolith removal and lacrimal sac abscess treatment.

  5. Verification of Caregraph (trademark) Peak Skin Dose Data Using Radiochromic Film


    during the experimental exposures. The phantom is 155 cm (5 ft. 1 in.) tall and weighs 55 kg (110 lb).34 It is transected horizontally into 2.5 cm...Techniques to estimate radiation dose to skin during fluoroscopically guided procedures, Phelps, B. (ed), AAPM Summer School Proceedings, Madison

  6. Psychophysical evaluation of the image quality of a dynamic flat-panel digital x-ray image detector using the threshold contrast detail detectability (TCDD) technique

    Davies, Andrew G.; Cowen, Arnold R.; Bruijns, Tom J. C.


    We are currently in an era of active development of the digital X-ray imaging detectors that will serve the radiological communities in the new millennium. The rigorous comparative physical evaluations of such devices are therefore becoming increasingly important from both the technical and clinical perspectives. The authors have been actively involved in the evaluation of a clinical demonstration version of a flat-panel dynamic digital X-ray image detector (or FDXD). Results of objective physical evaluation of this device have been presented elsewhere at this conference. The imaging performance of FDXD under radiographic exposure conditions have been previously reported, and in this paper a psychophysical evaluation of the FDXD detector operating under continuous fluoroscopic conditions is presented. The evaluation technique employed was the threshold contrast detail detectability (TCDD) technique, which enables image quality to be measured on devices operating in the clinical environment. This approach addresses image quality in the context of both the image acquisition and display processes, and uses human observers to measure performance. The Leeds test objects TO[10] and TO[10+] were used to obtain comparative measurements of performance on the FDXD and two digital spot fluorography (DSF) systems, one utilizing a Plumbicon camera and the other a state of the art CCD camera. Measurements were taken at a range of detector entrance exposure rates, namely 6, 12, 25 and 50 (mu) R/s. In order to facilitate comparisons between the systems, all fluoroscopic image processing such as noise reduction algorithms, were disabled during the experiments. At the highest dose rate FDXD significantly outperformed the DSF comparison systems in the TCDD comparisons. At 25 and 12 (mu) R/s all three-systems performed in an equivalent manner and at the lowest exposure rate FDXD was inferior to the two DSF systems. At standard fluoroscopic exposures, FDXD performed in an equivalent

  7. Pre-ablative high-resolution MRA facilitates electrophysiologic pulmonary vein ablation and reduces fluoroscopy time in patients with paroxysmal atrial fibrillation

    Collins, Jeremy D.; Pereles, F. S.; Bello, David; Betts, Timothy; Zachariah, Anish; Kaliney, Ryan; Song, Gina K.; Shors, Stephanie M.; Carr, James C.; Finn, John P.


    Pulmonary MRA generates high-resolution images of the pulmonary veins (PV) and left atrium (LA), permitting characterization of complex PV anatomy, which is useful in electrophysiologic PV catheter ablation, a proven technique for the treatment of paroxysmal atrial fibrillation (PAF). The purpose of this study was to determine if pre-ablative pulmonary MRA with intra-ablative viewing facilitates ablation by reducing fluoroscopy time. We studied the morphology of the LA and PV at 1.5T (Magnetom Sonata, Siemens Medical Solutions, Erlangen Germany) with breath-held gadolinium-enhanced 3D MRA in 7 patients with PAF undergoing PV ablation. Data was volume rendered (VR) on a stereoscopic workstation. PV ostial diameter and cross-sectional area measurements were obtained on multi-planar reformatted (MPR) images. VR datasets were converted into digital movies and were viewed on a laptop computer adjacent to real-time fluoroscopic images. Fluoroscopy times for patients undergoing pre-ablative MPA mapping were compared with a cohort of 22 consecutive patients diagnosed with PAF who underwent catheter ablation without pre-ablative MRA planning. Mean PV ablation fluoroscopic time with MRA planning versus fluoroscopic imaging alone were 84+/-20 minutes and 114+/-20 minutes respectively. Pre-ablative MRA planning resulted in a significant mean fluoroscopy time savings of 26% (p<0.05). In patients with PAF undergoing PV ablation, analysis of MRA datasets depicting PV anatomy confirms that there is great variability in anatomy between veins. Pre-ablative 3D PV mapping by MRA greatly facilitates fluoroscopic identification of individual veins and significantly reduces fluoroscopic radiation time.

  8. Radiation exposure from fluoroscopy during fixation of hip fracture and fracture of ankle: Effect of surgical experience

    Botchu Rajesh


    Full Text Available Background: Over the years, there has been a tremendous increase in the use of fluoroscopy in orthopaedics. The risk of contracting cancer is significantly higher for an orthopedic surgeon. Hip and spine surgeries account for 99% of the total radiation dose. The amount of radiation to patients and operating surgeon depends on the position of the patient and the type of protection used during the surgery. A retrospective study to assess the influence of the radiation exposure of the operating surgeon during fluoroscopically assisted fixation of fractures of neck of femur (dynamic hip screw and ankle (Weber B was performed at a district general hospital in the United Kingdom. Materials and Methods: Sixty patients with undisplaced intertrochanteric fracture were included in the hip group, and 60 patients with isolated fracture of lateral malleolus without communition were included in the ankle group. The hip and ankle groups were further divided into subgroups of 20 patients each depending on the operative experience of the operating surgeon. All patients had fluoroscopically assisted fixation of fracture by the same approach and technique. The radiation dose and screening time of each group were recorded and analyzed. Results: The radiation dose and screening time during fluoroscopically assisted fixation of fracture neck of femur were significantly high with surgeons and trainees with less than 3 years of surgical experience in comparison with surgeons with more than 10 years of experience. The radiation dose and screening time during fluoroscopically assisted fixation of Weber B fracture of ankle were relatively independent of operating surgeon′s surgical experience. Conclusion: The experience of operating surgeon is one of the important factors affecting screening time and radiation dose during fluoroscopically assisted fixation of fracture neck of femur. The use of snapshot pulsed fluoroscopy and involvement of senior surgeons could

  9. Pneumatic reduction of intussusception in children at Korle Bu Teaching Hospital: An initial experience

    Yaw Boateng Mensah


    Full Text Available Background: Intussusception is a common abdominal emergency in children which necessitates prompt diagnosis and management. Nonsurgical methods of managing this condition are rapidly gaining popularity with fluoroscopic-guided pneumatic reduction being one of such methods that has been used with great success in many countries. We present our initial experience with fluoroscopic-guided pneumatic reduction of intussusception at Korle Bu Teaching Hospital which is also the first time the technique has been used in Ghana. Materials and Methods: A total of 18 children were enrolled in the study between August 2007 and February 2008 at Korle Bu Teaching Hospital, Accra, Ghana. Patients were given air enema under fluoroscopic-guidance using locally assembled equipment. The intraluminal pressure was monitored with a pressure gauge and was not permitted to go above 120 mmHg. A total of three attempts of 3 min each were allowed. Results: There were 12 males and 6 females. The average age of the patients was 8.3 months (SD= 3 months. Twelve (67% of the cases were reduced successfully while 6 (33% failed to reduce. A majority of those that did not reduced had symptoms for at least 2 days. Bowel perforation occurred in three (16.7% cases. Conclusion: Pneumatic reduction of intussusception is a cost-effective and rapid method of management of intussusception. It however has limitations like high reported rate of bowel perforation and limited ability to identify lead points. The benefits however seem to outweigh these challenges, such as fluoroscopic-guided pneumatic reduction has a very high success rate. Fluoroscopic guided pneumatic reduction should be considered as one of the primary modes of reduction in Ghana and other neighbouring countries that are yet to practice it.

  10. Tangential View and Intraoperative Three-Dimensional Fluoroscopy for the Detection of Screw-Misplacements in Volar Plating of Distal Radius Fractures



    Full Text Available Background Volar locking plate fixation has become the gold standard in the treatment of unstable distal radius fractures. Juxta-articular screws should be placed as close as possible to the subchondral zone, in an optimized length to buttress the articular surface and address the contralateral cortical bone. On the other hand, intra-articular screw misplacements will promote osteoarthritis, while the penetration of the contralateral bone surface may result in tendon irritations and ruptures. The intraoperative control of fracture reduction and implant positioning is limited in the common postero-anterior and true lateral two-dimensional (2D-fluoroscopic views. Therefore, additional 2D-fluoroscopic views in different projections and intraoperative three-dimensional (3D fluoroscopy were recently reported. Nevertheless, their utility has issued controversies. Objectives The following questions should be answered in this study; 1 Are the additional tangential view and the intraoperative 3D fluoroscopy useful in the clinical routine to detect persistent fracture dislocations and screw misplacements, to prevent revision surgery? 2 Which is the most dangerous plate hole for screw misplacement? Patients and Methods A total of 48 patients (36 females and 13 males with 49 unstable distal radius fractures (22 x 23 A; 2 x 23 B, and 25 x 23 C were treated with a 2.4 mm variable angle LCP Two-Column volar distal radius plate (Synthes GmbH, Oberdorf, Switzerland during a 10-month period. After final fixation, according to the manufactures' technique guide and control of implant placement in the two common perpendicular 2D-fluoroscopic images (postero-anterior and true lateral, an additional tangential view and intraoperative 3D fluoroscopic scan were performed to control the anatomic fracture reduction and screw placements. Intraoperative revision rates due to screw misplacements (intra-articular or overlength were evaluated. Additionally, the number of

  11. Open reduction and internal fixation aided by intraoperative 3-dimensional imaging improved the articular reduction in 72 displaced acetabular fractures

    Eckardt, Henrik; Lind, Dennis; Toendevold, Erik


    Background and purpose - During acetabular fracture surgery, the acetabular roof is difficult to visualize with 2-dimensional fluoroscopic views. We assessed whether intraoperative 3-dimensional (3D) imaging can aid the surgeon to achieve better articular reduction and improve implant fixation....... Patients and methods - We operated on 72 acetabular fractures using intraoperative 3D imaging and compared the operative results, duration of surgery, and complications with those for 42 consecutive acetabular fracture operations conducted using conventional fluoroscopic imaging. Postoperative reduction...... was evaluated on reconstructed coronal and sagittal images of the acetabulum. Results - The fracture severity and patient characteristics were similar in the 2 groups. In the 3D group, 46 of 72 patients (0.6) had a perfect result after open reduction and internal fixation, and in the control group, 17 of 42 (0...

  12. Does Imaging Modality Used For Percutaneous Renal Access Make a Difference?

    Andonian, Sero; Scoffone, Cesare; Louie, Michael K;


    OBJECTIVE To assess peri-operative outcomes of percutaneous nephrolithotomy (PCNL) using ultrasound or fluoroscopic guidance for percutaneous access. METHODS A prospectively collected international CROES database containing 5806 patients treated with PCNL was used for the study. Patients were...... divided into two groups based on the methods of percutaneous access: ultrasound vs. fluoroscopy. Patient characteristics, operative data and post-operative outcomes were compared. RESULTS Percutaneous access was obtained using ultrasound guidance only in 453 patients (13.7%) and fluoroscopic guidance only...... in 2853 patients (86.3%). Comparisons were performed on a matched sample with 453 patients in each group. Frequency and pattern of Clavien complications did not differ between groups (P =.333). However, post-operative hemorrhage and transfusions were significantly higher in the fluoroscopy group: 6.0 vs...

  13. High-risk transseptal puncture in a patient with a “pancake” deformity in the left atrium caused by descending aorta displacement

    Takuro Nishimura, MD


    Full Text Available Catheter ablation via the transseptal approach has recently become a widely performed technique for treating atrial fibrillation (AF. However, fluoroscopic imaging provides limited anatomic guidance for the left atrial structure. We describe the case of a 78-year-old man who was referred to our hospital for pulmonary vein isolation for symptomatic paroxysmal AF. He had a history of pulmonary tuberculosis for which he had undergone a right upper lobectomy. A “pancake” deformity of the left atrium (LA was observed using 64-slice multislice computed tomography. We performed a transseptal puncture by using real-time three-dimensional transesophageal echocardiography (RT3D-TEE in combination with fluoroscopic imaging, without any complications. Although transseptal puncture can be performed without echocardiographic guidance in most patients, in our patient, RT3D-TEE proved to be a very helpful imaging technique to access the LA.

  14. The Principle of Digital Subtraction Angiography and Radiological Protection

    Okamoto, K.; Ito, J.; Sakai, K.; Yoshimura, S.


    Summary Recent improvements in x-ray technology have greatly contributed to the advancement of diagnostic imaging. Fluoroscopically guided neurointerventional procedures with digital subtraction angiography (DSΛ) are being performed with increasing frequency as the treatment of choice for a variety of neurovascular diseases. Radiation-induced skin injuries can occur after extended fluoroscopic exposure times, and the injuries have recently been reported. In this article, measured radiation doses at the surface of Rando Phantom with Skin Dose Monitor, and estimated and measured entrance skin doses in patients underwent neurointerventional procedures are reported as well as means of reducing radiation doses absorbed by patients and personnel to avoid occurrence of radiation-induced injuries. PMID:20667218

  15. Use of a radiopaque localizer grid to reduce radiation exposure

    Li Wentao


    Full Text Available Abstract Background Minimally invasive spine surgery requires placement of the skin incision at an ideal location in the patient's back by the surgeon. However, numerous fluoroscopic x-ray images are sometimes required to find the site of entry, thereby exposing patients and Operating Room personnel to additional radiation. To minimize this exposure, a radiopaque localizer grid was devised to increase planning efficiency and reduce radiation exposure. Results The radiopaque localizer grid was utilized to plan the point of entry for minimally invasive spine surgery. Use of the grid allowed the surgeon to accurately pinpoint the ideal entry point for the procedure with just one or two fluoroscopic X-ray images. Conclusions The reusable localizer grid is a simple and practical device that may be utilized to more efficiently plan an entry site on the skin, thus reducing radiation exposure. This device or a modified version may be utilized for any procedure involving the spine.

  16. Software innovations in computed tomography for structural heart disease interventions.

    Hell, Michaela; Marwan, Mohamed; Gaede, Luise; Achenbach, Stephan


    Computed tomography (CT) provides high, isotropic spatial resolution and has become firmly established in pre-procedural imaging for structural heart disease interventions. It allows determination of the exact dimensions of the target structure, provides information regarding the access route and permits identification of fluoroscopic projection angles to provide optimal visualisation for device placement. Several software solutions are available and have been systematically evaluated in the context of transcatheter aortic valve implantation (TAVI). The use of software products to perform automated measurements can be useful, especially when the experience and expertise regarding evaluation of CT in the context of structural heart disease are limited. In scientific studies, software has been demonstrated to provide accurate support for annulus sizing and prosthesis selection, to aid in reliably identifying patients in whom a transfemoral access may be problematic, and to suggest suitable angulations for fluoroscopic imaging to achieve an orthogonal view onto the aortic valve during implantation.

  17. Small bowel enteroclysis using a hemodialysis blood pump

    Lee, Soon Jin; Lim, Hyo Keun; Lee, Won Jae; Kim, Kyeong Ah; Lee, Yeon Ok; Hwang, Jung Hwa; Choi, Sang Hee; Lim, Jae Hoon [Samsung Medical Center, Seoul (Korea, Republic of)


    The purpose of this study is to describe the usefulness of small bowel enteroclysis using a hemodialysis blood pump. Over 1 16 month period, 135 double contrast small bowel enteroclysis examinations were performed in 132 patients using a hemodialysis blood pump. Following incubation of the proximal jejunum, barium at a dilution of 50 % and 0.5 %-methylcellulose were infused at a constant rate using a hemodialysis blood pump and multiple spot films of the small intestine were obtained. Success rate, quality of radiographs, positive findings, fluoroscopic time and complications were evaluated. It spite of the long fluoroscopic time and invasiveness, double contrast small bowel enteroclysis is useful for the evaluation of small bowel disease. The infusion of barium and methylcellulose using a hemodialysis blood pump give radiographs of good quality. (author). 18 refs., 2 tabs., 10 figs.

  18. Technique of Peritoneal Catheter Placement under Fluroscopic Guidance

    Ahmed Kamel Abdel-Aal


    Full Text Available Peritoneal catheters are mainly used for peritoneal dialysis in patients with end-stage renal disease. Other uses of this catheter include intraperitoneal chemotherapy and gene therapy for ovarian cancer and draining of uncontrolled refractory ascites in patients with liver cirrhosis. Traditionally, surgeons place most of these peritoneal catheters either by laparoscopy or open laparotomy. We detail our percutaneous approach to placing peritoneal catheters using fluoroscopic guidance. We emphasize the use of additional ultrasound guidance, including gray scale and color Doppler ultrasound, to determine the safest puncture site and to guide the initial needle puncture in order to avoid bowel perforation and injury to epigastric artery. We present our experience in placing peritoneal catheters using this technique in 95 patients with various indications. Fluoroscopic guided percutaneous placement of peritoneal catheters is a safe, minimally invasive, and effective alternative to open surgical or laparoscopic placement.

  19. Fluoroscopy guided percutaneous catheter drainage of pneumothorax in good mid-term patency with tube drainage

    Park, Ga Young; Oh, Joo Hyung; Yoon, Yup; Sung, Dong Wook [Kyung Hee University Hospital, Seoul (Korea, Republic of)


    To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. We retrospectively reviewed effectiveness of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n =4), reptured bullae (n = 2), and histiocytosis-X (n = 1). Three patients had iatrogenic pneumothorax caused by trauma (n = 1) and surgery (n = 2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. All catheter were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy.

  20. Evaluation of automated statistical shape model based knee kinematics from biplane fluoroscopy

    Baka, Nora; Kaptein, Bart L.; Giphart, J. Erik;


    State-of-the-art fluoroscopic knee kinematic analysis methods require the patient-specific bone shapes segmented from CT or MRI. Substituting the patient-specific bone shapes with personalizable models, such as statistical shape models (SSM), could eliminate the CT/MRI acquisitions, and thereby...... decrease costs and radiation dose (when eliminating CT). SSM based kinematics, however, have not yet been evaluated on clinically relevant joint motion parameters. Therefore, in this work the applicability of SSMs for computing knee kinematics from biplane fluoroscopic sequences was explored. Kinematic......-posterior tibial drawer, joint distraction-contraction, flexion, tibial rotation and adduction. The relationship between kinematic precision and bone shape accuracy was also investigated. The SSM based kinematics resulted in sub-millimeter (0.48-0.81mm) and approximately 1° (0.69-0.99°) median precision...

  1. Intraurethral Catheter: Alternative Management for Urinary Retention in Patients With Benign Prostatic Hypertrophy

    Sulabha Punekar; Ramkrishnan, Prem A.; Anand R. Kelkar; Date, Jaydeep A.; Vasudeo R. Ridhorkar


    A polyurethane intraurethral catheter (IUC) was used in 27 patients with benign prostatic hypertrophy who were unfit for surgery, or were awaiting surgery. All of them had previously had a periurethral catheter inserted. The IUC was inserted with a cystoscope under fluoroscopic control. Spontaneous voiding through the IUC resumed in 25 patients (93%) in the immediate postprocedure period. At the end of 6 months follow-up, the peak flow rates and the residual volumes estimated in 22 patients w...

  2. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization.

    Whiteside, Wendy; Christensen, Jason; Zampi, Jeffrey D


    Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI) overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver.

  3. Detector system comparison using relative CNR for specific imaging tasks related to neuro-endovascular image-guided interventions (neuro-EIGIs)

    Loughran, Brendan; Swetadri Vasan, S. N.; Singh, Vivek; Ionita, Ciprian N; Jain, Amit; Bednarek, Daniel R.; Rudin, Stephen


    Neuro-EIGIs require visualization of very small endovascular devices and small vessels. A Microangiographic Fluoroscope (MAF) x-ray detector was developed to improve on the standard flat panel detector’s (FPD’s) ability to visualize small objects during neuro-EIGIs. To compare the performance of FPD and MAF imaging systems, specific imaging tasks related to those encountered during neuro-EIGIs were used to assess contrast to noise ratio (CNR) of different objects. A bar phantom...

  4. Untangling of knotted urethral catheters

    Sambrook, Andrew J. [Aberdeen Royal Infirmary, Department of Radiology, Aberdeen (United Kingdom); Todd, Alistair [Raigmore Hospital, Inverness (United Kingdom)


    Intravesical catheter knotting during micturating cystourethrography is a rare but recognized complication of the procedure. We were able to untangle a knot utilizing a fluoroscopically guided vascular guidewire. Following this success, a small study was performed using a model. Various types of guidewires and techniques were tested for different diameters of knots in order to predict the likelihood of success in this type of situation. (orig.)

  5. A study on quality improvement of x-ray imaging of the respiratory-system based on a new image processing technique

    Torii, Jun; Nagai, Yuichi; Horita, Tatsuya; Matsumoto, Yuuji; Izumo, Takehiro; Kitagawa, Mayumi; Ihara, Kanyu; Nakamura, Tadashi; Mukoyoshi, Wataru; Tennmei, Kounosuke; Suzuki, Katsumi; Hara, Akio; Sasada, Shinji; Aso, Tomohiko


    Recently, the double contrast technique in a gastrointestinal examination and the transbronchial lung biopsy in an examination for the respiratory system [1-3] have made a remarkable progress. Especially in the transbronchial lung biopsy, better quality of x-ray fluoroscopic images is requested because this examination is performed under a guidance of x-ray fluoroscopic images. On the other hand, various image processing methods [4] for x-ray fluoroscopic images have been developed as an x-ray system with a flat panel detector [5-7] is widely used. New noise reduction processing, Adaptive Noise Reduction [ANR], was announced in SPIE last year.[8] ANR is a new image processing technique which is capable of extracting and reducing noise components regardless of moving objects in fluoroscopy images. However, for further enhancement of noise reduction effect in clinical use, it was used in combination with a recursive filter, which is a time axis direction filter. Due to this, the recursive filter generated image lags when there are moving objects in the fluoroscopic images, and these image lags sometimes became hindrance in performing smooth bronchoscopy. This is because recursive filters reduce noise by adding multiple fluoroscopy images. Therefore, we have developed new image processing technique, Motion Tracking Noise Reduction [MTNR] for decreasing image lags as well as noise. This ground-breaking image processing technique detects global motion in images with high accuracy, determines the pixels to track the motion, and applies a motion tracking-type time filter. With this, image lags are removed remarkably while realizing the effective noise reduction. In this report, we will explain the effect of MTNR by comparing the performance of MTNR images [MTNR] and ANR + Recursive filter-applied images [ANR + Recursive filter].

  6. ICRP PUBLICATION 120: Radiological protection in cardiology.

    Cousins, C; Miller, D L; Bernardi, G; Rehani, M M; Schofield, P; Vañó, E; Einstein, A J; Geiger, B; Heintz, P; Padovani, R; Sim, K-H


    Cardiac nuclear medicine, cardiac computed tomography (CT), interventional cardiology procedures, and electrophysiology procedures are increasing in number and account for an important share of patient radiation exposure in medicine. Complex percutaneous coronary interventions and cardiac electrophysiology procedures are associated with high radiation doses. These procedures can result in patient skin doses that are high enough to cause radiation injury and an increased risk of cancer. Treatment of congenital heart disease in children is of particular concern. Additionally, staff(1) in cardiac catheterisation laboratories may receive high doses of radiation if radiological protection tools are not used properly. The Commission provided recommendations for radiological protection during fluoroscopically guided interventions in Publication 85, for radiological protection in CT in Publications 87 and 102, and for training in radiological protection in Publication 113 (ICRP, 2000b,c, 2007a, 2009). This report is focused specifically on cardiology, and brings together information relevant to cardiology from the Commission's published documents. There is emphasis on those imaging procedures and interventions specific to cardiology. The material and recommendations in the current document have been updated to reflect the most recent recommendations of the Commission. This report provides guidance to assist the cardiologist with justification procedures and optimisation of protection in cardiac CT studies, cardiac nuclear medicine studies, and fluoroscopically guided cardiac interventions. It includes discussions of the biological effects of radiation, principles of radiological protection, protection of staff during fluoroscopically guided interventions, radiological protection training, and establishment of a quality assurance programme for cardiac imaging and intervention. As tissue injury, principally skin injury, is a risk for fluoroscopically guided interventions

  7. Gene Therapy for Fracture Repair


    case, the external catheter hub is visible (D), though the internal tubing cannot be visualized by X-Ray. 11 MLV-based vector with BMP-2/4...catheter) injection. Top: A fluoroscope was used to visualize a radio- opaque contrast dye during a percutaneous injection from the lateral aspect...analysis was performed using ImaGene software (BioDiscovery, El Segundo, CA), that used an internal statistical analysis of the signal intensity of

  8. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization

    Wendy Whiteside


    Full Text Available Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver.

  9. A case of misplaced permacath dialysis catheter

    Mohammed Arshad Ali


    Full Text Available Central venous placement using ultrasound has significantly reduced the complications associated with blind puncture. The central venous catheter can still get misplaced if it follows an anomalous route after appropriate puncture of desired vessel. We report a case of misplaced dialysis catheter into the accessory hemiazygos vein which resulted in a large hemothorax, and we recommend the routine use of a fluoroscope for placement of dialysis catheters so as to avoid serious complications.

  10. Fluoroscopy-induced radionecrosis

    Tchanque-Fossuo, Catherine N.; Kamangar, Faranak; Ho, Baran; Chang, Shurong; Dahle, Sara E.; Schulman, Joshua M.; Isseroff, R Rivkah


    Complications from radiation exposure during fluoroscopic guidance of cardiac catheterization may occur. With repeated procedures, the risk for cutaneous injuries increases. Herein, we describe a 59-year-old man with extensive coronary artery disease, who had undergone multiple revascularization procedures and developed a non-healing ulcer on his left inferior scapula. The patient’s medical history, physical exam findings, and histopathology gave clues to a case of radiation-induced dermatiti...

  11. Chronic radiodermatitis following cardiac catheterisation: a report of two cases and a brief review of the literature

    Dehen, L; Vilmer, C; Humiliere, C; Corcos, T; Pentousis, D.; Ollivaud, L; Chatelain, D.; Dubertret, L


    Cardiac angiography produces one of the highest radiation exposures of any commonly used diagnostic x ray procedure. Recently, serious radiation induced skin injuries have been reported after repeated therapeutic interventional procedures using prolonged fluoroscopic imaging. Two male patients, aged 62 and 71 years, in whom chronic radiodermatitis developed one to two years after two consecutive cardiac catheterisation procedures are reported. Both patients had undergone lengthy procedures us...

  12. Surgeons’ Perceptions of Spinal Navigation: Analysis of Key Factors Affecting the Lack of Adoption of Spinal Navigation Technology

    Choo, Alexander D.; Regev, Gilad; Garfin, Steven R.; Kim, Choll W.


    Background Computer-assisted spinal navigation allows for real time localization of surgical instruments in multiple views. Its use decreases radiation exposure and clears the surgical field of the C-arm fluoroscope. Despite these advantages, spinal navigation has yet to gain general acceptance among spine surgeons. The purpose of this study is to survey spine surgeons about their opinions on the strengths and weaknesses of spinal navigation. Methods Spine surgeons from the membership of the ...

  13. Radiation dose reduction in intra-arterial chemotherapy infusion for intraocular retinoblastoma.

    Cooke, Daniel L; Stout, Charles E; Kim, Warren T; Hetts, Steven W; Higashida, Randall T; Halbach, Van V; Dowd, Christopher F; Gould, Robert G


    Retinoblastoma (RB) is a rare malignancy affecting the pediatric population. Intravenous chemotherapy is the longstanding delivery method, although intra-arterial (IA) chemotherapy is gaining popularity given the reduced side effects compared with systemic chemotherapy administration. Given the sensitivity of the target organ, patient age, and secondary tumor susceptibility, a premium has been placed on minimizing procedural related radiation exposure. To reduce patient x-ray dose during the IA infusion procedure, customized surgical methods and fluoroscopic techniques were employed. The routine fluoroscopic settings were changed from the standard 7.5 pulses/s and dose level to the detector of 36 nGy/pulse, to a pulse rate of 4 pulses/s and detector dose to 23 nGy/pulse. The angiographic dose indicators (reference point air kerma (Ka) and fluoroscopy time) for a cohort of 10 consecutive patients (12 eyes, 30 infusions) were analyzed. An additional four cases (five eyes, five infusions) were analyzed using dosimeters placed at anatomic locations to reflect scalp, eye, and thyroid dose. The mean Ka per treated eye was 20.1±11.9 mGy with a mean fluoroscopic time of 8.5±4.6 min. Dosimetric measurements demonstrated minimal dose to the lens (0.18±0.10 mGy). Measured entrance skin doses varied from 0.7 to 7.0 mGy and were 73.4±19.7% less than the indicated Ka value. Ophthalmic arterial melphalan infusion is a safe and effective means to treat RB. Modification to contemporary fluoroscopic systems combined with parsimonious fluoroscopy can minimize radiation exposure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to

  14. Untangling of knotted urethral catheters.

    Sambrook, Andrew J; Todd, Alistair


    Intravesical catheter knotting during micturating cystourethrography is a rare but recognized complication of the procedure. We were able to untangle a knot utilizing a fluoroscopically guided vascular guidewire. Following this success, a small study was performed using a model. Various types of guidewires and techniques were tested for different diameters of knots in order to predict the likelihood of success in this type of situation.

  15. Computerized tomography using a modified orthogonal tangent correction algorithm.

    Hsia, T C; Smith, S C; Lantz, B M


    A modified orthogonal tangent correction algorithm is presented for computerized tomography. The algorithm uses four X-rays scans spaced 45 degrees apart, to reconstruct a transverse axial image. The reconstruction procedure is interative in which image matrix elements are corrected by alternately matching the two sets of orthogonal scan data. The algorithm has been applied to phantom data as well as to video recorded fluoroscopic data.

  16. Scaled, patient-specific 3D vertebral model reconstruction based on 2D lateral fluoroscopy.

    Zheng, Guoyan; Nolte, Lutz-P; Ferguson, Stephen J


    Accurate three-dimensional (3D) models of lumbar vertebrae are required for image-based 3D kinematics analysis. MRI or CT datasets are frequently used to derive 3D models but have the disadvantages that they are expensive, time-consuming or involving ionizing radiation (e.g., CT acquisition). An alternative method using 2D lateral fluoroscopy was developed. A technique was developed to reconstruct a scaled 3D lumbar vertebral model from a single two-dimensional (2D) lateral fluoroscopic image and a statistical shape model of the lumbar vertebrae. Four cadaveric lumbar spine segments and two statistical shape models were used for testing. Reconstruction accuracy was determined by comparison of the surface models reconstructed from the single lateral fluoroscopic images to the ground truth data from 3D CT segmentation. For each case, two different surface-based registration techniques were used to recover the unknown scale factor, and the rigid transformation between the reconstructed surface model and the ground truth model before the differences between the two discrete surface models were computed. Successful reconstruction of scaled surface models was achieved for all test lumbar vertebrae based on single lateral fluoroscopic images. The mean reconstruction error was between 0.7 and 1.6 mm. A scaled, patient-specific surface model of the lumbar vertebra from a single lateral fluoroscopic image can be synthesized using the present approach. This new method for patient-specific 3D modeling has potential applications in spine kinematics analysis, surgical planning, and navigation.

  17. Modification of the coaxial technique for selective salpingography with measurement of tubal perfusion pressures.

    Papaioannou, Spyros; Afnan, Masoud; McHugo, Josephine M; Coomarasamy, Aravinthan; Ola, Bolarinde; Sharif, Khaldoun


    This article describes the use of the fallopotorque catheter system for transcervical selective salpingography and tubal catheterization under fluoroscopic guidance for the diagnosis and treatment of obstruction of the proximal Fallopian tube. The technique of tubal perfusion pressure assessment during the procedure, using the same catheter system, is also described. The relative advantages of this method of selective salpingography and tubal catheterization are then discussed in the background of previously described techniques.

  18. Dental Implant Placement using C-arm CT Real Time Imaging System: A Case Report.

    Rajkumar, B; Boruah, Lalit C; Thind, Amandeep; Jain, Gaurav; Gupta, Shilpi


    C-arm computed tomography (CT) is a new and innovative imaging technique. In combination with two-dimensional fluoroscopic or radiographic imaging, information provided by three-dimensional C-arm real time imaging can be valuable for therapy planning, guidance and outcome assessment in dental implant placement. This paper reports a case of two dental implant placement using Artis zee C-arm CT system first time in field of implantology.

  19. Transoral C2 biopsy and vertebroplasty

    Kaminsky, Ian A.; Härtl, Roger; Sigounas, Dimitri; Mlot, Stefan; Patsalides, Athos


    Pathologic fractures involving the C2 vertebral body and odontoid process pose a unique dilemma, as the surgical approach for direct odontoid process screw fixation has several limitations. There have been a small number of transoral approach C2 vertebroplasty or kyphoplasty reported in the literature. Previous attempts were performed utilizing fluoroscopy or CT guidance. We report a case of a fluoroscopically guided transor-al approach vertebroplasty in a patient with a lyt...

  20. Entrapment of J-tip guidewires by Venatech and stainless-steel Greenfield vena cava filters during central venous catheter placement: percutaneous management in four patients.

    Andrews, R T; Geschwind, J F; Savader, S J; Venbrux, A C


    We present four patients in whom bedside placement of a central venous catheter was complicated by entrapment of a J-tip guidewire by a previously placed vena cava (VC) filter. Two Venatech filters were fragmented and displaced into the superior VC or brachiocephalic vein during attempted withdrawal of the entrapped wire. Two stainless-steel Greenfield filters remained in place and intact. Fluoroscopically guided extraction of both wires entrapped by Greenfield filters was successfully performed in the angiography suite.

  1. Reduction of radiation exposure in catheter ablation of atrial fibrillation: Lesson learned

    Roberto; De; Ponti


    Over the last decades, the concern for the radiation injury hazard to the patients and the professional staff has increased in the medical community. Since there is no magnitude of radiation exposure that is known to be completely safe, the use of ionizing radiation during medical diagnostic or interventional procedures should be as low as reasonably achievable(ALARA principle). Nevertheless, in cardiovascular medicine, radiation exposure for coronary percutaneous interventions or catheter ablation of cardiac arrhythmias may be high: for ablation of a complex arrhythmia, such as atrial fibrillation, the mean dose can be > 15 m Sv and in some cases > 50 m Sv. In interventional electrophysiology, although fluoroscopy has been widely used since the beginning to navigate catheters in the heart and the vessels and to monitor their position, the procedure is not based on fluoroscopic imaging. Therefore, nonfluoroscopic three-dimensional systems can be used to navigate electrophysiology catheters in the heart with no or minimal use of fluoroscopy. Although zerofluoroscopy procedures are feasible in limited series, there may be difficulties in using no fluoroscopy on a routine basis. Currently, a significant reduction in radiation exposure towards near zero-fluoroscopy procedures seems a simpler task to achieve, especially in ablation of complex arrhythmias, such as atrial fibrillation. The data reported in the literature suggest the following three considerations. First, the use of the non-fluoroscopic systems is associated with a consistent reduction in radiation exposure in multiple centers: the more sophisticated and reliable this technology is, the higher the reduction in radiation exposure. Second, the use of these systems does not automatically lead to reduction of radiation exposure, but an optimized workflow should be developed and adopted for a safe non-fluoroscopic navigation of catheters. Third, at any level of expertise, there is a specific learning curve for

  2. Safety of 1000 CT-guided steroid injections with air used to localize the epidural space.

    Chang, A; Pochert, S; Romano, C; Brook, A; Miller, T


    Historically, ESIs were performed without any imaging guidance, resulting in erroneous placement in up to 30% of injections. Fluoroscopic imaging is now used to guide most procedures. Recently, several reports have described the use of CT to guide ESIs instead of fluoroscopy. CT provides the ability to use air as contrast to localize the epidural space. This retrospective review will discuss findings in 1000 CT-guided ESIs with air localization.

  3. Biliopancreatic ascariasis: endoscopic approach.

    Kamiya, Toshiaki; Justiniano, Mario; Durán, Abel; Uechi, Chikara


    From June 1985 to June 1999, 120 patients were diagnosed by means of panendoscopy, choledocoscopy, and endoscopic retrograde cholangiopancreatography as having biliary and pancreatic ascariasis. All duodenoscopic procedures were performed under fluoroscopic control. Endoscopic extraction was successful in 99 of 108 (92%) patients, some of whom had had previous endoscopic sphincterotomy. The endoscopic accessories used were a basket catheter, polypectomy snare, and balloon catheter. Because no significant complications were observed after this endoscopic treatment, we recommend endoscopic extractions for biliary ascariasis.

  4. Optimization of fluoroscopy parameters using pattern matching prediction in the real-time tumor-tracking radiotherapy system.

    Miyamoto, Naoki; Ishikawa, Masayori; Bengua, Gerard; Sutherland, Kenneth; Suzuki, Ryusuke; Kimura, Suguru; Shimizu, Shinichi; Onimaru, Rikiya; Shirato, Hiroki


    In the real-time tumor-tracking radiotherapy system, fluoroscopy is used to determine the real-time position of internal fiducial markers. The pattern recognition score (PRS) ranging from 0 to 100 is computed by a template pattern matching technique in order to determine the marker position on the fluoroscopic image. The PRS depends on the quality of the fluoroscopic image. However, the fluoroscopy parameters such as tube voltage, current and exposure duration are selected manually and empirically in the clinical situation. This may result in an unnecessary imaging dose from the fluoroscopy or loss of the marker because of too much or insufficient x-ray exposure. In this study, a novel optimization method is proposed in order to minimize the fluoroscopic dose while keeping the image quality usable for marker tracking. The PRS can be predicted in a region where the marker appears to move in the fluoroscopic image by the proposed method. The predicted PRS can be utilized to judge whether the marker can be tracked with accuracy. In this paper, experiments were performed to show the feasibility of the PRS prediction method under various conditions. The predicted PRS showed good agreement with the measured PRS. The root mean square error between the predicted PRS and the measured PRS was within 1.44. An experiment using a motion controller and an anthropomorphic chest phantom was also performed in order to imitate a clinical fluoroscopy situation. The result shows that the proposed prediction method is expected to be applicable in a real clinical situation.

  5. [Technical solution to a complication caused by intra-arterial catheterization].

    Oliu Torres, O; Pedroso Mendoza, L E; Figueredo Barreras, F; Corteguera Fonte, M E


    Knot formation in the distal segment of an angiographic catheter is not very frequent. Its early recognition, as well as domination of several techniques in order to untie it, may avoid surgery. An unique technique in order to untie a knot in a catheter is described, which consists in using other more rigid catheter with "J" shaped end by contralateral femoral via and under direct fluoroscopic visualization, with image magnifier and fitted TV.

  6. Simultaneous management for retrocaval ureter and ipsilateral renal stone using retroperitoneoscopic approach: report of a case

    Suzuki, Shouji; Sawada, Norifumi; Haheda,Yaburu; Zakoji, Hidenori; Tsuchida, Takayuki; Aikawa,Masami; Adaki ,Isao; Takeda, Masayuki


    A 32-year-old male presented with a month history of right back and flank pain and a possibility of gross hematuria. As part of the initial evaluation abdominal ultrasound revealed marked right hydronephrosis. An excretion urogram showed delayed excretion of contrast material extending to the L4 level distally. Computed omography revealed right renal pelvic stone and right retrocaval ureter. At surgery, a right-sided ouble-J ureteric stent was placed under fluoroscopic guidance. Retroperitone...

  7. Is there possibility of radioinduced deterministic effect during procedures of cardiac catheterism in patients?; Existe a possibilidade de inducao de efeito deterministico da radiacao ionizante durante procedimentos de cateterismo cardiaco em pacientes?

    Medeiros, Rogerio Fachel de; Bacelar, Alexandre; Zimerman, Leandro Ioschpe [Hospital das Clinicas, Porto Alegre, RS (Brazil). Servico de Engenharia Biomedica. Grupo de Pesquisa e Pos-graduacao


    In this work were presented 22 cases of radiation deterministic effect in patients submitted to catheterism procedures by means of X-fluoroscope. Evaluation of the results suggest that the most of patients receive potential skin entrance doses over 2 Gy and some of them may have received doses over 12 Gy. At these doses, radiation induced erythema, ulceration and necrosis are all possible complications if the same entrance skin surface is exposed for the duration of the procedure.

  8. Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy

    Waugh, R.; McCarty, M. [Div. of Radiology, South Cleveland Hospital, South Tees Acute Hospitals NHS Trust, Marton Road, Middlesbrough, Cleveland (United Kingdom); McCallum, H.M. [Regional Medical Physics Dept., South Cleveland Hospital, Middlesbrough (United Kingdom); Montgomery, R. [Dept. of Orthopaedics, South Tees Hospitals NITS Trust, Middlesbrough (United Kingdom); Aszkenasy, M. [Tees and North East Yorkshire NHS Trust, West Lane Hospital, Middlesbrough (United Kingdom)


    Background. An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. Objective. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Materials and methods. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Results. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83 %, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Conclusion. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving. (orig.)

  9. Pylorus-preserving whipple pancreaticoduodenectomy : CT findings of immediate postoperative complications

    Kim, Keon Woo; Kim, Tae Hun [Kyungpook National Univ., Taegu (Korea, Republic of). School of Medicine


    The purpose of this paper is to determine the CT findings of immediately postoperative complications including anastomotic leakage, and to evaluate the usefulness of CT scan in the assessment of early postoperative complications of pylorus preserving whipple pancreaticoduodenectomy (PPPD). During the early postoperative period, fluid accumulated in the abdominal cavity of ten of 23 patients who had undergone PPPD. In all cases, the time interval between the first follow up CT scan and surgery was no more than two weeks. At each leakage site, we compared CT findings with those of conventional fluoroscopic studies: upper gastrointestinal studies with oral water-soluble contrast materials, a contrast injection study via drainage catheters in place in the stomach, the site of choledochojejunostomy during surgery and pancreaticojejunostomy, and nine cases of sinogram via percutaneous drainage catheters. We also evaluated CT findings of the locations, amounts, and margin of the fluid collections. If conventional fluoroscopic studies showed no evidence of anastomotic leakage, as was the case with six patients, the leakage site was determined on the basis of clinical and laboratory data. In four of the six, this was found to be the site of pancreaticojejunostomy, and in the other two, an abscess without anastomotic leakage. In some cases of suspected complications arising after PPPD, and including anastomotic leakage and abdominal abscess, leakage is not revealed by conventional fluoroscopic studies; in such cases, CT scanning may help detect the complications and determine the site of anastomotic leakage. (author). 10 refs., 2 figs.

  10. A system for finding a 3D target without a 3D image

    West, Jay B.; Maurer, Calvin R., Jr.


    We present here a framework for a system that tracks one or more 3D anatomical targets without the need for a preoperative 3D image. Multiple 2D projection images are taken using a tracked, calibrated fluoroscope. The user manually locates each target on each of the fluoroscopic views. A least-squares minimization algorithm triangulates the best-fit position of each target in the 3D space of the tracking system: using the known projection matrices from 3D space into image space, we use matrix minimization to find the 3D position that projects closest to the located target positions in the 2D images. A tracked endoscope, whose projection geometry has been pre-calibrated, is then introduced to the operating field. Because the position of the targets in the tracking space is known, a rendering of the targets may be projected onto the endoscope view, thus allowing the endoscope to be easily brought into the target vicinity even when the endoscope field of view is blocked, e.g. by blood or tissue. An example application for such a device is trauma surgery, e.g., removal of a foreign object. Time, scheduling considerations and concern about excessive radiation exposure may prohibit the acquisition of a 3D image, such as a CT scan, which is required for traditional image guidance systems; it is however advantageous to have 3D information about the target locations available, which is not possible using fluoroscopic guidance alone.

  11. Technical advances of interventional fluoroscopy and flat panel image receptor.

    Lin, Pei-Jan Paul


    In the past decade, various radiation reducing devices and control circuits have been implemented on fluoroscopic imaging equipment. Because of the potential for lengthy fluoroscopic procedures in interventional cardiovascular angiography, these devices and control circuits have been developed for the cardiac catheterization laboratories and interventional angiography suites. Additionally, fluoroscopic systems equipped with image intensifiers have benefited from technological advances in x-ray tube, x-ray generator, and spectral shaping filter technologies. The high heat capacity x-ray tube, the medium frequency inverter generator with high performance switching capability, and the patient dose reduction spectral shaping filter had already been implemented on the image intensified fluoroscopy systems. These three underlying technologies together with the automatic dose rate and image quality (ADRIQ) control logic allow patients undergoing cardiovascular angiography procedures to benefit from "lower patient dose" with "high image quality." While photoconductor (or phosphor plate) x-ray detectors and signal capture thin film transistor (TFT) and charge coupled device (CCD) arrays are analog in nature, the advent of the flat panel image receptor allowed for fluoroscopy procedures to become more streamlined. With the analog-to-digital converter built into the data lines, the flat panel image receptor appears to become a digital device. While the transition from image intensified fluoroscopy systems to flat panel image receptor fluoroscopy systems is part of the on-going "digitization of imaging," the value of a flat panel image receptor may have to be evaluated with respect to patient dose, image quality, and clinical application capabilities. The advantage of flat panel image receptors has yet to be fully explored. For instance, the flat panel image receptor has its disadvantages as compared to the image intensifiers; the cost of the equipment is probably the most

  12. Comparative analysis of anterior and posterior contrast injection approaches for shoulder MR arthrograms in adolescents

    Gupton, Theodore B.; Cahill, Anne M. [The Children' s Hospital of Philadelphia, Division of Interventional Radiology, Department of Radiology, Philadelphia, PA (United States); Delgado, Jorge [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Jaramillo, Diego [Stanford University Medical Center, Diagnostic Radiology, Palo Alto, CA (United States); Chauvin, Nancy A. [The Children' s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Musculoskeletal Imaging, Department of Radiology, Philadelphia, PA (United States)


    There is no consensus in the literature concerning the optimal approach for performing a fluoroscopically guided shoulder arthrogram injection in a pediatric population. To compare adequacy of capsular injection and radiation doses between fluoroscopically guided anterior and posterior glenohumeral joint contrast injections in adolescents. We evaluated imaging in 67 adolescents (39 boys, 28 girls; mean age 16.0 years; range 11.7-19.1 years) who underwent an anterior approach glenohumeral contrast injection with subsequent MR imaging, and 67 age- and gender-matched subjects (39 boys, 28 girls; mean age 16.0 years; range 11.1-19.2 years) who underwent a posterior approach injection during the period June 2010 to September 2015. Two pediatric radiologists independently evaluated all MR shoulder arthrograms to assess adequacy of capsular distention and degree of contrast extravasation. We recorded total fluoroscopic time, dose-area product (DAP) and cumulative air kerma (CAK). There were no significant differences in age, gender, height, weight or body mass index between the populations (P-values > 0.6). The amount of contrast extravasation between the groups was not significantly different (P = 0.27). Three anterior injections (4.5%) and one posterior (1.5%) were suboptimal (P = 0.62). Fluoroscopy time was not different: 1.1 min anterior and 1.3 min posterior (P = 0.14). There was a significant difference in CAK (0.7 mGy anterior and 1.1 mGy posterior; P = 0.007) and DAP (5.3 μGym{sup 2} anterior and 9.4 μGym{sup 2} posterior; P = 0.008). Inter-rater agreement was excellent (Cohen kappa >0.81). Both techniques were technically successful. There was no difference in the fluoroscopy time for either approach. The radiation dose was higher with the posterior approach but this is of questionable clinical significance. (orig.)

  13. Evaluation of low-dose limits in 3D-2D rigid registration for surgical guidance

    Uneri, A.; Wang, A. S.; Otake, Y.; Kleinszig, G.; Vogt, S.; Khanna, A. J.; Gallia, G. L.; Gokaslan, Z. L.; Siewerdsen, J. H.


    An algorithm for intensity-based 3D-2D registration of CT and C-arm fluoroscopy is evaluated for use in surgical guidance, specifically considering the low-dose limits of the fluoroscopic x-ray projections. The registration method is based on a framework using the covariance matrix adaptation evolution strategy (CMA-ES) to identify the 3D patient pose that maximizes the gradient information similarity metric. Registration performance was evaluated in an anthropomorphic head phantom emulating intracranial neurosurgery, using target registration error (TRE) to characterize accuracy and robustness in terms of 95% confidence upper bound in comparison to that of an infrared surgical tracking system. Three clinical scenarios were considered: (1) single-view image + guidance, wherein a single x-ray projection is used for visualization and 3D-2D guidance; (2) dual-view image + guidance, wherein one projection is acquired for visualization, combined with a second (lower-dose) projection acquired at a different C-arm angle for 3D-2D guidance; and (3) dual-view guidance, wherein both projections are acquired at low dose for the purpose of 3D-2D guidance alone (not visualization). In each case, registration accuracy was evaluated as a function of the entrance surface dose associated with the projection view(s). Results indicate that images acquired at a dose as low as 4 μGy (approximately one-tenth the dose of a typical fluoroscopic frame) were sufficient to provide TRE comparable or superior to that of conventional surgical tracking, allowing 3D-2D guidance at a level of dose that is at most 10% greater than conventional fluoroscopy (scenario #2) and potentially reducing the dose to approximately 20% of the level in a conventional fluoroscopically guided procedure (scenario #3).

  14. SU-E-P-13: Quantifying the Geometric Error Due to Irregular Motion in Four-Dimensional Computed Tomography (4DCT)

    Sawant, A [UT Southwestern Medical Center, Dallas, TX (United States)


    Purpose: Respiratory correlated 4DCT images are generated under the assumption of a regular breathing cycle. This study evaluates the error in 4DCT-based target position estimation in the presence of irregular respiratory motion. Methods: A custom-made programmable externally-and internally-deformable lung motion phantom was placed inside the CT bore. An abdominal pressure belt was placed around the phantom to mimic clinical 4DCT acquisitio and the motion platform was programmed with a sinusoidal (±10mm, 10 cycles per minute) motion trace and 7 motion traces recorded from lung cancer patients. The same setup and motion trajectories were repeated in the linac room and kV fluoroscopic images were acquired using the on-board imager. Positions of 4 internal markers segmented from the 4DCT volumes were overlaid upon the motion trajectories derived from the fluoroscopic time series to calculate the difference between estimated (4DCT) and “actual” (kV fluoro) positions. Results: With a sinusoidal trace, absolute errors of the 4DCT estimated markers positions vary between 0.78mm and 5.4mm and RMS errors are between 0.38mm to 1.7mm. With irregular patient traces, absolute errors of the 4DCT estimated markers positions increased significantly by 100 to 200 percent, while the corresponding RMS error values have much smaller changes. Significant mismatches were frequently found at peak-inhale or peak-exhale phase. Conclusion: As expected, under conditions of well-behaved, periodic sinusoidal motion, the 4DCT yielded much better estimation of marker positions. When an actual patient trace is used 4DCT-derived positions showed significant mismatches with the fluoroscopic trajectories, indicating the potential for geometric and therefore dosimetric errors in the presence of cycle-to-cycle respiratory variations.

  15. Skeletal imaging following reconstruction of the posterior cruciate ligament: in vivo comparison of fluoroscopy, radiography, and computed tomography

    Osti, Michael; Benedetto, Karl Peter [Academic Hospital Feldkirch, Department for Trauma Surgery and Sports Traumatology, Feldkirch (Austria); Krawinkel, Alessa [Academic Hospital Feldkirch, Department for Radiology, Feldkirch (Austria)


    Intra- and postoperative validation of anatomic footprint replication in posterior cruciate ligament (PCL) reconstruction can be conducted using fluoroscopy, radiography, or computed tomography (CT) scans. However, effectiveness and exposure to radiation of these imaging modalities are unknown. The objective of this study was to evaluate the comparative effectiveness of fluoroscopy, radiography, and CT in detecting femoral and tibial tunnel positions following an all-inside reconstruction of the PCL ligament in vivo. The study design was a retrospective case series. Intraoperative fluoroscopic images, postoperative radiographs, and CT scans were obtained in 50 consecutive patients following single-bundle PCL reconstruction. The centers of the tibial and femoral tunnel apertures were identified and correlated to measurement grid systems. The results of fluoroscopic, radiographic, and CT measurements were compared to each other and accumulated radiation dosages were calculated. Comparing the imaging groups, no statistically significant difference could be detected for the reference of the femoral tunnel to the intercondylar depth and height, for the reference of the tibial tunnel to the mediolateral diameter of the tibial plateau and for the superoinferior distance of the tibial tunnel entry to the tibial plateau and to the former physis line. Effective doses resulting from fluoroscopic, radiographic, and CT exposure averaged 2.9 mSv, standard deviation (±SD) 4.1 mSv, to 1.3 ± 0.8 mSv and to 3.6 ± 1.0 mSv, respectively. Fluoroscopy, radiography, and CT yield approximately equal effectiveness in detecting parameters used for quality validation intra- and postoperatively. An accumulating exposure to radiation must be considered. (orig.)

  16. Treatment of gastric outlet and duodenal obstructions with uncovered expandable metal stents


    AIM: To investigate and evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided peroral uncovered expandable metal stent placement to treat gastric outlet and duodenal obstructions. METHODS: Fifteen consecutive patients underwent peroral placement of WallstentTM Enteral Endoprosthesis to treat gastric outlet and duodenal obstructions (14 malignant, 1 benign). All procedures were completed under fluoroscopic guidance without endoscopic assistance. Follow-up was completed until the patients died or were lost, and the clinical outcomes were analyzed. RESULTS: The technique success rate was 100%, and the oral intake was maintained in 12 of 14 patients varying from 7 d to 270 d. Two patients remained unable to resume oral intake, although their stents were proven to be patent with the barium study. One patient with acute necrotizing pancreatitis underwent enteral stenting to treat intestinal obstruction, and nausea and vomiting disappeared. Ten patients died during the followup period, and their mean oral intake time was 50 d. No procedure-related complications occurred. Stent migration to the gastric antrum occurred in one patient 1 year after the procedure, a tumor grew at the proximal end of the stent in another patient 38 d post-stent insertion. CONCLUSION: Fluoroscopically guided peroral metal stent implantation is a safe and effective method to treat malignant gastrointestinal obstructions, and complications can be ignored based on our short-term study. Indications for this procedure should be discreetly considered because a few patients may not benefit from gastrointestinal insertion, but some benign gastrointestinal obstructions can be treated using this procedure.

  17. Anatomy-based registration of CT-scan and intraoperative X-ray images for guiding a surgical robot.

    Guéziec, A; Kazanzides, P; Williamson, B; Taylor, R H


    We describe new methods for rigid registration of a preoperative computed tomography (CT)-scan image to a set of intraoperative X-ray fluoroscopic images, for guiding a surgical robot to its trajectory planned from CT. Our goal is to perform the registration, i.e., compute a rotation and translation of one data set with respect to the other to within a prescribed accuracy, based upon bony anatomy only, without external fiducial markers. With respect to previous approaches, the following aspects are new: 1) we correct the geometric distortion in fluoroscopic images and calibrate them directly with respect to the robot by affixing to it a new calibration device designed as a radiolucent rod with embedded metallic markers, and by moving the device along two planes, while radiographs are being acquired at regular intervals; 2) the registration uses an algorithm for computing the best transformation between a set of lines in three space, the (intraoperative) X-ray paths, and a set of points on the surface of the bone (imaged preoperatively), in a statistically robust fashion, using the Cayley parameterization of a rotation; and 3) to find corresponding sets of points to the X-ray paths on the surfaces, our new approach consists of extracting the surface apparent contours for a given viewpoint, as a set of closed three-dimensional nonplanar curves, before registering the apparent contours to X-ray paths. Aside from algorithms, there are a number of major technical difficulties associated with engineering a clinically viable system using anatomy and image-based registration. To detect and solve them, we have so far conducted two experiments with the surgical robot in an operating room (OR), using CT and fluoroscopic image data of a cadaver bone, and attempting to faithfully simulate clinical conditions. Such experiments indicate that intraoperative X-ray-based registration is a promising alternative to marker-based registration for clinical use with our proposed method.

  18. Assessment of the dose distribution inside a cardiac cath lab using TLD measurements and Monte Carlo simulations

    Baptista, M.; Teles, P.; Cardoso, G.; Vaz, P.


    Over the last decade, there was a substantial increase in the number of interventional cardiology procedures worldwide, and the corresponding ionizing radiation doses for both the medical staff and patients became a subject of concern. Interventional procedures in cardiology are normally very complex, resulting in long exposure times. Also, these interventions require the operator to work near the patient and, consequently, close to the primary X-ray beam. Moreover, due to the scattered radiation from the patient and the equipment, the medical staff is also exposed to a non-uniform radiation field that can lead to a significant exposure of sensitive body organs and tissues, such as the eye lens, the thyroid and the extremities. In order to better understand the spatial variation of the dose and dose rate distributions during an interventional cardiology procedure, the dose distribution around a C-arm fluoroscopic system, in operation in a cardiac cath lab at Portuguese Hospital, was estimated using both Monte Carlo (MC) simulations and dosimetric measurements. To model and simulate the cardiac cath lab, including the fluoroscopic equipment used to execute interventional procedures, the state-of-the-art MC radiation transport code MCNPX 2.7.0 was used. Subsequently, Thermo-Luminescent Detector (TLD) measurements were performed, in order to validate and support the simulation results obtained for the cath lab model. The preliminary results presented in this study reveal that the cardiac cath lab model was successfully validated, taking into account the good agreement between MC calculations and TLD measurements. The simulated results for the isodose curves related to the C-arm fluoroscopic system are also consistent with the dosimetric information provided by the equipment manufacturer (Siemens). The adequacy of the implemented computational model used to simulate complex procedures and map dose distributions around the operator and the medical staff is discussed, in

  19. Markerless gating for lung cancer radiotherapy based on machine learning techniques

    Lin Tong; Li Ruijiang; Tang Xiaoli; Jiang, Steve B [Department of Radiation Oncology, University of California San Diego, La Jolla, CA 92093 (United States); Dy, Jennifer G [Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115 (United States)], E-mail:


    In lung cancer radiotherapy, radiation to a mobile target can be delivered by respiratory gating, for which we need to know whether the target is inside or outside a predefined gating window at any time point during the treatment. This can be achieved by tracking one or more fiducial markers implanted inside or near the target, either fluoroscopically or electromagnetically. However, the clinical implementation of marker tracking is limited for lung cancer radiotherapy mainly due to the risk of pneumothorax. Therefore, gating without implanted fiducial markers is a promising clinical direction. We have developed several template-matching methods for fluoroscopic marker-less gating. Recently, we have modeled the gating problem as a binary pattern classification problem, in which principal component analysis (PCA) and support vector machine (SVM) are combined to perform the classification task. Following the same framework, we investigated different combinations of dimensionality reduction techniques (PCA and four nonlinear manifold learning methods) and two machine learning classification methods (artificial neural networks-ANN and SVM). Performance was evaluated on ten fluoroscopic image sequences of nine lung cancer patients. We found that among all combinations of dimensionality reduction techniques and classification methods, PCA combined with either ANN or SVM achieved a better performance than the other nonlinear manifold learning methods. ANN when combined with PCA achieves a better performance than SVM in terms of classification accuracy and recall rate, although the target coverage is similar for the two classification methods. Furthermore, the running time for both ANN and SVM with PCA is within tolerance for real-time applications. Overall, ANN combined with PCA is a better candidate than other combinations we investigated in this work for real-time gated radiotherapy.

  20. Combination of CT scanning and fluoroscopy imaging on a flat-panel CT scanner

    Grasruck, M.; Gupta, R.; Reichardt, B.; Suess, Ch.; Schmidt, B.; Stierstorfer, K.; Popescu, S.; Brady, T.; Flohr, T.


    We developed and evaluated a prototype flat-panel detector based Volume CT (fpVCT) scanner. The fpVCT scanner consists of a Varian 4030CB a-Si flat-panel detector mounted in a multi slice CT-gantry (Siemens Medical Solutions). It provides a 25 cm field of view with 18 cm z-coverage at the isocenter. In addition to the standard tomographic scanning, fpVCT allows two new scan modes: (1) fluoroscopic imaging from any arbitrary rotation angle, and (2) continuous, time-resolved tomographic scanning of a dynamically changing viewing volume. Fluoroscopic imaging is feasible by modifying the standard CT gantry so that the imaging chain can be oriented along any user-selected rotation angle. Scanning with a stationary gantry, after it has been oriented, is equivalent to a conventional fluoroscopic examination. This scan mode enables combined use of high-resolution tomography and real-time fluoroscopy with a clinically usable field of view in the z direction. The second scan mode allows continuous observation of a timeevolving process such as perfusion. The gantry can be continuously rotated for up to 80 sec, with the rotation time ranging from 3 to 20 sec, to gather projection images of a dynamic process. The projection data, that provides a temporal log of the viewing volume, is then converted into multiple image stacks that capture the temporal evolution of a dynamic process. Studies using phantoms, ex vivo specimens, and live animals have confirmed that these new scanning modes are clinically usable and offer a unique view of the anatomy and physiology that heretofore has not been feasible using static CT scanning. At the current level of image quality and temporal resolution, several clinical applications such a dynamic angiography, tumor enhancement pattern and vascularity studies, organ perfusion, and interventional applications are in reach.

  1. MediGuide-impact on catheter ablation techniques and workflow.

    Pillarisetti, Jayasree; Kanmanthareddy, Arun; Reddy, Yeruva Madhu; Lakkireddy, Dhanunjaya


    Since the introduction of percutaneous intervention in modern medical science, specifically cardiovascular medicine fluoroscopy has remained the gold standard for navigation inside the cardiac structures. As the complexity of the procedures continue to increase with advances in interventional electrophysiology, the procedural times and fluoroscopy times have proportionately increased and the risks of radiation exposure both to the patients as well as the operator continue to rise. 3D electroanatomic mapping systems have to some extent complemented fluoroscopic imaging in improving catheter navigation and forming a solid platform for exploring the electroanatomic details of the target substrate. The 3D mapping systems are still limited as they continue to be static representations of a dynamic heart without being completely integrated with fluoroscopy. The field needed a technological solution that could add a dynamic positioning system that can be successfully incorporated into fluoroscopic imaging as well as electroanatomic imaging modalities. MediGuide is one such innovative technology that exploits the geo-positioning system principles. It employs a transmitter mounted on the X-ray panel that emits an electromagnetic field within which sensor-equipped diagnostic and ablation catheters are tracked within prerecorded fluoroscopic images. MediGuide is also integrated with NavX mapping system and helps in developing better 3D images by field scaling-a process that reduces field distortions that occur from impedance mapping alone. In this review, we discuss about the principle of MediGuide technology, the catheter ablation techniques, and the workflow in the EP lab for different procedures.

  2. Video-guided calibration of an augmented reality mobile C-arm.

    Chen, Xin; Naik, Hemal; Wang, Lejing; Navab, Nassir; Fallavollita, Pascal


    The augmented reality (AR) fluoroscope augments an X-ray image by video and provides the surgeon with a real-time in situ overlay of the anatomy. The overlay alignment is crucial for diagnostic and intra-operative guidance, so precise calibration of the AR fluoroscope is required. The first and most complex step of the calibration procedure is the determination of the X-ray source position. Currently, this is achieved using a biplane phantom with movable metallic rings on its top layer and fixed X-ray opaque markers on its bottom layer. The metallic rings must be moved to positions where at least two pairs of rings and markers are isocentric in the X-ray image. The current "trial and error" calibration process currently requires acquisition of many X-ray images, a task that is both time consuming and radiation intensive. An improved process was developed and tested for C-arm calibration. Video guidance was used to drive the calibration procedure to minimize both X-ray exposure and the time involved. For this, a homography between X-ray and video images is estimated. This homography is valid for the plane at which the metallic rings are positioned and is employed to guide the calibration procedure. Eight users having varying calibration experience (i.e., 2 experts, 2 semi-experts, 4 novices) were asked to participate in the evaluation. The video-guided technique reduced the number of intra-operative X-ray calibration images by 89% and decreased the total time required by 59%. A video-based C-arm calibration method has been developed that improves the usability of the AR fluoroscope with a friendlier interface, reduced calibration time and clinically acceptable radiation doses.

  3. Robust patella motion tracking using intensity-based 2D-3D registration on dynamic bi-plane fluoroscopy: towards quantitative assessment in MPFL reconstruction surgery

    Otake, Yoshito; Esnault, Matthieu; Grupp, Robert; Kosugi, Shinichi; Sato, Yoshinobu


    The determination of in vivo motion of multiple-bones using dynamic fluoroscopic images and computed tomography (CT) is useful for post-operative assessment of orthopaedic surgeries such as medial patellofemoral ligament reconstruction. We propose a robust method to measure the 3D motion of multiple rigid objects with high accuracy using a series of bi-plane fluoroscopic images and a multi-resolution, intensity-based, 2D-3D registration. A Covariance Matrix Adaptation Evolution Strategy (CMA-ES) optimizer was used with a gradient correlation similarity metric. Four approaches to register three rigid objects (femur, tibia-fibula and patella) were implemented: 1) an individual bone approach registering one bone at a time, each with optimization of a six degrees of freedom (6DOF) parameter, 2) a sequential approach registering one bone at a time but using the previous bone results as the background in DRR generation, 3) a simultaneous approach registering all the bones together (18DOF) and 4) a combination of the sequential and the simultaneous approaches. These approaches were compared in experiments using simulated images generated from the CT of a healthy volunteer and measured fluoroscopic images. Over the 120 simulated frames of motion, the simultaneous approach showed improved registration accuracy compared to the individual approach: with less than 0.68mm root-mean-square error (RMSE) for translation and less than 1.12° RMSE for rotation. A robustness evaluation was conducted with 45 trials of a randomly perturbed initialization showed that the sequential approach improved robustness significantly (74% success rate) compared to the individual bone approach (34% success) for patella registration (femur and tibia-fibula registration had a 100% success rate with each approach).

  4. C-arm cone-beam CT combined with a new electromagnetic navigation system for guidance of percutaneous needle biopsies. Initial clinical experience

    Kickuth, R.; Reichling, C.; Bley, T.; Hahn, D.; Ritter, C. [University Hospital of Wuerzburg (Germany). Inst. of Diagnostic and Interventional Radiology


    To evaluate the feasibility and efficacy of C-arm fluoroscopic cone-beam computed tomography (CACT) in combination with a new electromagnetic tracking (EMT) system for needle guidance during percutaneous biopsies. 53 patients were referred for biopsy of thoracic (n = 19) and abdominal (n = 34) lesions. CT-like images of the anatomical region of interest (ROI) were generated using a flat panel-based angiographic system. These images were transmitted to an EMT system. A coaxial puncture needle with a sensor in its tip was connected with the navigation system and tracked into an electromagnetic field created via a field generator. Data generated within this field were merged with the CACT images. On a monitor both the anatomical ROI and needle tip position were displayed to enable precise needle insertion into the target. Through the coaxial needle, biopsy specimens for the histologic evaluation were extracted. Number of representative biopsy samples, number of core biopsies/patient, total procedure time, dose-area product, fluoroscopic time, and complications were recorded. 53 CACT/EMT-guided biopsy procedures were performed, 48 of which (91 %) yielded representative tissue samples. Four core biopsies were obtained from each patient. 40 (75 %) lesions were malignant and 13 (25 %) lesions were benign. The total procedure time was 9 ± 5 min (range, 3 - 23 min), fluoroscopic time was 0.8 ± 0.4 min (range, 0.4 - 2 min). The mean dose-area product (cGy cm{sup 2}) was 7373 (range, 895 - 26 904). The rate of complications (1 pneumothorax, 2 hemoptyses) was 6 %. CACT combined with EMT appears to be a feasible and effective technique for the guidance of percutaneous biopsies with a low rate of therapeutically relevant complications.

  5. Percutaneous Mesocaval Shunt Creation in a Patient with Chronic Portal and Superior Mesenteric Vein Thrombosis

    Bercu, Zachary L., E-mail:; Sheth, Sachin B., E-mail: [Icahn School of Medicine at Mount Sinai, Division of Interventional Radiology (United States); Noor, Amir, E-mail: [The George Washington University School of Medicine and Health Sciences (United States); Lookstein, Robert A., E-mail:; Fischman, Aaron M., E-mail:; Nowakowski, F. Scott, E-mail:; Kim, Edward, E-mail:; Patel, Rahul S., E-mail: [Icahn School of Medicine at Mount Sinai, Division of Interventional Radiology (United States)


    The creation of a transjugular intrahepatic portosystemic shunt (TIPS) is a critical procedure for the treatment of recurrent variceal bleeding and refractory ascites in the setting of portal hypertension. Chronic portal vein thrombosis remains a relative contraindication to conventional TIPS and options are limited in this scenario. Presented is a novel technique for management of refractory ascites in a patient with hepatitis C cirrhosis and chronic portal and superior mesenteric vein thrombosis secondary to schistosomiasis and lupus anticoagulant utilizing fluoroscopically guided percutaneous mesocaval shunt creation.

  6. Multimodality Imaging Evaluation of an Uncommon Entity: Esophageal Heterotopic Pancreas

    Takman Mack


    Full Text Available A 25-year-old male was referred to the Radiology Department with new onset of right upper quadrant and epigastric abdominal pain. He had no past medical or surgical history. Physical exam was unremarkable. The patient underwent computed tomography (CT, fluoroscopic upper gastrointestinal (GI evaluation, endoscopic ultrasound (EUS, and positron emission tomography (PET evaluation, revealing the presence of a heterogeneous esophageal mass. In light of imaging findings and clinical workup, the patient was ultimately referred for thorascopic surgery. Surgical findings and histology confirmed the diagnosis of esophageal heterotopic pancreas.

  7. Patient-bounded extrapolation using low-dose priors for volume-of-interest imaging in C-arm CT

    Xia, Y.; Maier, A.; Berger, M.; Hornegger, J. [Pattern Recognition Lab, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91058 (Germany); Bauer, S. [Siemens AG, Healthcare Sector, Forchheim 91301 (Germany)


    Purpose: Three-dimensional (3D) volume-of-interest (VOI) imaging with C-arm systems provides anatomical information in a predefined 3D target region at a considerably low x-ray dose. However, VOI imaging involves laterally truncated projections from which conventional reconstruction algorithms generally yield images with severe truncation artifacts. Heuristic based extrapolation methods, e.g., water cylinder extrapolation, typically rely on techniques that complete the truncated data by means of a continuity assumption and thus appear to be ad-hoc. It is our goal to improve the image quality of VOI imaging by exploiting existing patient-specific prior information in the workflow. Methods: A necessary initial step prior to a 3D acquisition is to isocenter the patient with respect to the target to be scanned. To this end, low-dose fluoroscopic x-ray acquisitions are usually applied from anterior–posterior (AP) and medio-lateral (ML) views. Based on this, the patient is isocentered by repositioning the table. In this work, we present a patient-bounded extrapolation method that makes use of these noncollimated fluoroscopic images to improve image quality in 3D VOI reconstruction. The algorithm first extracts the 2D patient contours from the noncollimated AP and ML fluoroscopic images. These 2D contours are then combined to estimate a volumetric model of the patient. Forward-projecting the shape of the model at the eventually acquired C-arm rotation views gives the patient boundary information in the projection domain. In this manner, we are in the position to substantially improve image quality by enforcing the extrapolated line profiles to end at the known patient boundaries, derived from the 3D shape model estimate. Results: The proposed method was evaluated on eight clinical datasets with different degrees of truncation. The proposed algorithm achieved a relative root mean square error (rRMSE) of about 1.0% with respect to the reference reconstruction on

  8. Minimally Invasive Spinal Surgery with Intraoperative Image-Guided Navigation

    Terrence T. Kim


    Full Text Available We present our perioperative minimally invasive spine surgery technique using intraoperative computed tomography image-guided navigation for the treatment of various lumbar spine pathologies. We present an illustrative case of a patient undergoing minimally invasive percutaneous posterior spinal fusion assisted by the O-arm system with navigation. We discuss the literature and the advantages of the technique over fluoroscopic imaging methods: lower occupational radiation exposure for operative room personnel, reduced need for postoperative imaging, and decreased revision rates. Most importantly, we demonstrate that use of intraoperative cone beam CT image-guided navigation has been reported to increase accuracy.

  9. Non-operative residual biliary stone extraction by using steerable catheter and basket

    Kim, K. W.; Chang, J. C.; Park, C. Y. [Yonsei University College of Medicine, Seoul (Korea, Republic of)


    Nonoperative residual biliary stone removal through the T-tube sinus tract was performed in 9 patients by using steerable catheter and basket under fluoroscopic guidance and the result was satisfactory. There is no significant complication or morbidity. We concluded that this method is 1. easy of performance, highly successful and of no demonstrable risk. 2. can be performed without any medication and in our patient department. 3. the method of choice of treatment in post-op residual biliary stone with T-tube.

  10. Evaluation of periprosthetic bone cysts in patients with a scandinavian total ankle replacement

    Jensen, Janni; Frøkjær, Johnny; Gerke, Oke;


    OBJECTIVE. Periprosthetic bone cysts are a known finding after total ankle replacement (TAR). The significance of cysts is uncertain, but they may threaten the long-term survival of the implant. The aim of this prospective study was to evaluate the diagnostic accuracy of weight-bearing digital...... radiography compared with 3D weight-bearing multiplanar reconstructed (MPR) fluoroscopic imaging when diagnosing periprosthetic bone cysts in patients who have undergone TAR. SUBJECTS AND METHODS. Forty-two consecutive patients with a Scandinavian Total Ankle Replacement (STAR) were consecutively enrolled...

  11. Lateral sided snapping elbow caused by a meniscus: two case reports and literature review.

    Kang, Shin-Taek; Kim, Tae-Ho


    Lateral sided snapping elbow is an unusual condition, and it is apt to be misdiagnosed as lateral epicondylitis. The causes of lateral sided snapping elbow have been attributed to intraarticular loose bodies, instability, synovial plicae and torn annular ligament. We report our experiences for treating lateral sided snapping elbow caused by a meniscus in the radio-humeral joint. In the present cases, the cause of snapping was detected using double contrast arthrogram under fluoroscopic control, and histology revealed that it was a meniscus. Complete removal of the meniscus allowed immediate relief of the symptom, and there was no recurrence in both cases.

  12. Effect of triple tibial osteotomy on femorotibial stability in canine cranial cruciate ligament deficient stifles

    Kristiansen, S.; Vedel, T.; Jensen, B. R.

    leveling osteotomy (TPLO), have been biomechanically evaluated (Kipfer et al. (2008), Apelt et al. (2007), Butler et al. (2011), Pozzi et al. (2006) and Rey et al. (2014)), experimental studies on TTO are lacking. The aim of this study was to evaluate the effect of TTO on cadaveric stifle stability....... Limbs were mounted on a custom-made frame, which permitted controlled movement of the tibia relative to the femur, and extended from full flexion whilst recording the stifle region fluoroscopically. Metal markers placed at the CrCL attachment sites were used to monitor cranial tibial subluxation (CTS...

  13. Penetration of Günther Tulip filter struts through an introducer sheath: case report and safety concerns.

    Contractor, Sohail G; Merkulov, Alex; Bhatti, Waseem; Lee, Michael; Gardner, Kim


    The authors present a patient who had a Günther-Tulip inferior vena cava filter placed under fluoroscopic guidance. The filter struts were seen to penetrate through the introducer sheath at deployment. This was believed to be secondary to a kink in the sheath at the site of venous entry and was due to the patient's nuchal obesity as well as his inability to turn his head to the opposite side. The introducer sheath was then placed through a long reinforced metal sheath through which the filter was then placed without complication.

  14. Computer-assisted navigation systems for insertion of cannulated screws in femoral neck fractures: a comparison of bi-planar robot navigation with optoelectronic navigation in a Synbone hip model trial

    WANG Jun-qiang; ZHAO Chun-peng; SU Yong-gang; ZHOU Li; HU Lei; WANG Tian-miao; WANG Man-yi


    Background Computer-assisted procedures have recently been introduced for navigated femoral neck screw placement.Currently there is little information available regarding accuracy and efficiency of the different navigated procedures.The aim of this study was to compare two fluoroscopic navigation tracking technologies,a novel bi-planar robot navigation and standardized optoelectronic navigation,versus standard freehand fluoroscopic insertion in a Synbone hip model.Methods Eighteen fixed Synbone hip models were divided into 3 groups.C-arm navigated cannulated screws (AO-ASIF,diameter 7.3 mm) were inserted using freehand targeting (control group).A novel bi-planar robot system (TINAV,GD2000) and an optoelectronic system (Stryker OTS Navigation System) were used for the navigated procedures (robot group and optoelectronic group).Accuracy was measured using radiographic evaluation including the measurement of screw parallelism and decentralization,and joint penetration.To evaluate the efficiency,the number of guidewire passes,operative time and fluoroscopic images taken were noted.Results The two computer-assisted systems provided significantly improved accuracy compared to the freehand technique.Each of the parameters,including guidewire passes and number of fluoroscopy images,was significantly lower when using the computer-assisted systems than for freehand-unguided insertion (P <0.05),but operative time was significantly shorter when using freehand-unguided insertion than for the computer-assisted systems (P <0.05).Accuracy,operative time and number of fluoroscopy images taken were similar among the two navigated groups (P >0.05),but guidewire passes in the robot group were significantly less than in the optoelectronic group (P <0.05).Conclusions Both bi-planar robot navigation and optoelectronic navigation were similarly accurate and have the potential to improve accuracy and reduce radiation for freehand fluoroscopic targeting for insertion of cannulated

  15. Management of a chronic carotid artery pseudoaneurysm.

    Baker, Aaron C; Arko, Frank R; Zarins, Christopher K; Lee, Eugene S


    An 82-year-old female with a history of right carotid endarterectomy with patch closure 12 years prior presents with a pulsatile right neck mass with skin erosion and bleeding. The patient had been previously evaluated but refused the surgical intervention because a median sternotomy was recommended to obtain adequate proximal control. Her aneurysm was successfully repaired using a combination of open and endovascular method. The repair was performed through a right-hand side anterior sternocleidomastoid neck incision, and proximal vascular control was obtained with an 8.5-mm balloon positioned under fluoroscopic guidance via a femoral puncture.

  16. Successful Treatment of Acute Lymphoblastic Leukemia in a Child with Trisomy 21 and Complex Congenital Heart Disease with Mechanical Prosthetic Valve

    Saima Alvi


    Full Text Available A 10-year-old girl with trisomy 21 and complex congenital heart disease presented with acute lymphoblastic leukemia. Her chemotherapy required modifications due to poor baseline cardiac status and a mechanical prosthetic heart valve that was dependent on anticoagulation. We describe our management including the use of low-molecular-weight heparin as anticoagulation for a mechanical heart valve, the safe delivery of intrathecal chemotherapy included bridging with unfractionated heparin, and the use of fluoroscopic guidance to minimize the risk of bleeding. Adjustments were made to avoid anthracyclines. The child tolerated therapy well without complications and remains relapse free five years after diagnosis.

  17. Intraoperative visualisation of the trigeminal cistern. Intraoperative Darstellung der Trigeminuszisterne

    Bockermann, V.; Dieckmann, G. (Goettingen Univ. (Germany). Abt. Funktionelle Neurochirurgie)


    Percutaneous retrogassarian glycerol rhizotomy has passed the test of time as an immediately effective and reliable method for the treatment of trigeminal neuralgia. X-ray-assisted puncture of the trigeminal cistern and contrast-enhanced intraoperative visualisation techniques are absolute requirements of this surgical measure and invariably precede any further steps taken by the surgeon. The use of state-of-the-art fluoroscopic methods ensures that ample information is even obtained from the images of the base-of-scull region. (orig.).

  18. US and RTG guided percutaneous biliary drainage; Przezskorny drenaz drog zolciowych monitorowany usg i rtg

    Bukowski, J. [Pomorska Akademia Medyczna, Szczecin (Poland)


    Under combined US and fluoroscopic guidance from anterior approach through left liver lobe a Seldinger technique was used for biliary drainage in 46 patients with nonresectable malignant biliary obstruction. In 9 cases of hilar tumor separating both hepatic ducts a second catheter was inserted through right liver lobe. In 11 cases an internal-external drainage was established. In 3 cases the externally drained bile was recycled by connecting the transhepatic catheter to a percutaneous gastrostomy also performed under US guidance. No severe complications were observed. A described drainage technique provides an effective palliative intervention for advanced biliary malignancies. (author). 18 refs, 6 figs.

  19. Interventional radiography and mortality risks in U.S. radiologic technologists

    Linet, Martha S.; Freedman, D.M.; Sigurdson, Alice J.; Doody, Michele M. [National Cancer Institute, Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, Bethesda, MD (United States); Hauptmann, Michael [National Cancer Institute, Biostatistics Branch, Division of Cancer Epidemiology and Genetics, Bethesda, MD (United States); Alexander, Bruce H. [University of Minnesota, Division of Environmental Health Sciences, Minneapolis, MN (United States); Miller, Jeremy [Information Management Services, Inc., Rockville, MD (United States)


    With the exponential increase in minimally invasive fluoroscopically guided interventional radiologic procedures, concern has increased about the health effects on staff and patients of radiation exposure from these procedures. There has been no systematic epidemiologic investigation to quantify serious disease risks or mortality. To quantify all-cause, circulatory system disease and cancer mortality risks in U.S. radiologic technologists who work with interventional radiographic procedures, we evaluated mortality risks in a nationwide cohort of 88,766 U.S. radiologic technologists (77% female) who completed a self-administered questionnaire during 1994-1998 and were followed through 31 December 2003. We obtained information on work experience, types of procedures (including fluoroscopically guided interventional procedures), and protective measures plus medical, family cancer history, lifestyle, and reproductive information. Cox proportional hazards regression models were used to compute relative risks (RRs) with 95% confidence intervals (CIs). Between completion of the questionnaire and the end of follow-up, there were 3,581 deaths, including 1,209 from malignancies and 979 from circulatory system diseases. Compared to radiologic technologists who never or rarely performed or assisted with fluoroscopically guided interventional procedures, all-cause mortality risks were not increased among those working on such procedures daily. Similarly, there was no increased risk of mortality resulting from all circulatory system diseases combined, all cancers combined, or female breast cancer among technologists who daily performed or assisted with fluoroscopically guided interventional procedures. Based on small numbers of deaths (n=151), there were non-significant excesses (40%-70%) in mortality from cerebrovascular disease among technologists ever working with these procedures. The absence of significantly elevated mortality risks in radiologic technologists reporting the

  20. Aplicación del bloqueo del ganglio estrellado en el tratamiento de dos pacientes con angina refractaria crónica Use of stellate ganglion blockade in two patients with chronic refractory angina

    M. P. Papa de la Rosa; D. Fiandra; J. Muzetti


    Objetivo: Evaluación y seguimiento de dos pacientes a los que se les realizó la técnica del Bloqueo del Ganglio Estrellado (BGE) como tratamiento del angor refractario. Casos clínicos: Se controla durante un período de 12 meses la evolución de dos pacientes con angina crónica refractaria a los que se les realizó la técnica de BGE por abordaje anterior izquierdo bajo fluoroscopía. Durante el control evolutivo se registraron la aparición de episodios anginosos y su relación con la actividad dia...

  1. The cementless AGC 2000 knee prosthesis: 20-year results in a consecutive series

    Eriksen, Jamila; Christensen, Jan; Solgaard, Søren


    One hundred and fourteen AGC 2000 porous-coated cementless total knee arthroplasties were performed in 102 patients between 1984 and 1986. We report their 20-year results with patient assessment, Hospital for Special Surgery knee score, weight-bearing radiographs done under fluoroscopic control...... and survivorship analyses. All patients could be accounted for. With prosthesis revision as a failure criterion, the cumulative survival rate of all prosthetic components at 20 years was 84.4%. The fall in success rate was primarily due to early tibial and late patellar component failure. The cumulative survival...


    Kozanek, Michal; Hosseini, Ali; Liu, Fang; Van de Velde, Samuel K.; Gill, Thomas J.; Rubash, Harry E.; Li, Guoan


    Accurate knowledge of the dynamic knee motion in vivo is instrumental for understanding normal and pathological function of the knee joint. However, interpreting motion of the knee joint during gait in other than the sagittal plane remains controversial. In this study, we utilized the dual fluoroscopic imaging technique to investigate the six-degree of freedom kinematics and condylar motion of the knee during the stance phase of treadmill gait in eight healthy volunteers at a speed of 0.67m/s...

  3. Fish bone as a nidus for stone formation in the common bile duct: report of two cases

    Kim, Young Hwan; Lee, Sang Kwon; Kwon, Jung Hyeok; Woo, Seong Ku [Dongsan Medical Center, Keimyung University College of Medicine, Daegu (Korea, Republic of); Kim, Yong Joo [Andong General Hospital, Andong (Korea, Republic of); Park, Won Kyu [Youngnam University Hospital, Daegu (Korea, Republic of)


    We report two cases of common bile duct stone formed around a fish bone which migrated from the intestinal tract, along with their characteristic imaging findings. Two patients who had no history of previous operation were admitted because of cholangitis. Percutaneous transhepatic biliary drainage (PTBD) was performed and the cholangiogram showed filling defects with an unusually elongated shape in the common bile duct. After improvement of the cholangitic symptoms, the stones were removed through the PTBD tract under fluoroscopic guidance. A nidus consisting of a 1.5 cm sized fish bone was found in each stone removed.

  4. Early experience with X-ray magnetic resonance fusion for low-flow vascular malformations in the pediatric interventional radiology suite

    Hwang, Tiffany J. [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Keck School of Medicine of the University of Southern California, Los Angeles, CA (United States); Girard, Erin [Siemens Corporation, Corporate Technology, Princeton, NJ (United States); Shellikeri, Sphoorti; Vossough, Arastoo; Ho-Fung, Victor; Cahill, Anne Marie [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Setser, Randolph [Siemens Medical Solutions USA, Inc., Hoffman Estates, IL (United States)


    This technical innovation describes our experience using an X-ray magnetic resonance fusion (XMRF) software program to overlay 3-D MR images on real-time fluoroscopic images during sclerotherapy procedures for vascular malformations at a large pediatric institution. Five cases have been selected to illustrate the application and various clinical utilities of XMRF during sclerotherapy procedures as well as the technical limitations of this technique. The cases demonstrate how to use XMRF in the interventional suite to derive additional information to improve therapeutic confidence with regards to the extent of lesion filling and to guide clinical management in terms of intraprocedural interventional measures. (orig.)

  5. Endoscope-guided pneumatic dilation for treatment of esophageal achalasia

    Seng-Kee; Chuah; Tsung-Hui; Hu; Chi-Sin; Changchien


    Pneumatic dilation(PD) is considered to be the first line nonsurgical therapy for achalasia.The principle of the procedure is to weaken the lower esophageal sphincter by tearing its muscle fibers by generating radial force.The endoscope-guided procedure is done without fluoroscopic control.Clinicians usually use a lowcompliance balloon such as Rigiflex dilator to perform endoscope-guided PD for the treatment of esophageal achalasia.It has the advantage of determining mucosal injury during the dilation proce...

  6. Utility of the NavX® Electroanatomic Mapping System for Permanent Pacemaker Implantation in a Pregnant Patient with Chagas Disease

    Alejandro Velasco, MD


    Full Text Available Chagas disease is a highly prevalent zoonosis in Mexico, Central, and South America. Early cardiac involvement is one of the most serious complications of this disease, and conduction disturbances may occur at an early age. We describe a young pregnant woman with Chagas disease and a high degree atrioventricular block, who required implantation of a permanent dual chamber pacemaker. Using an electroanatomic navigation EnSite NavX® system the pacemaker was successfully implanted with minimal fluoroscopic exposure. This case demonstrates the safety and feasibility of using an electroanatomic navigation system to guide permanent pacemaker implantation minimizing x-ray exposure in pregnant patients.

  7. Percutaneous tricuspid valve-In-ring replacement for the treatment of recurrent severe tricuspid regurgitation.

    Condado, Jose; Leonardi, Robert; Babaliaros, Vasilis


    Percutaneous tricuspid valve-in-ring replacement can be an alternative to surgery for high-risk patients with symptomatic severe tricuspid regurgitation that recurs after surgical ring repair. Practitioners must pay attention to the specific technical details associated with this procedure that include: using the ring as a fluoroscopic landmark, sizing the valve area with multi-modality imaging, choosing the appropriate device based on the patients anatomy, and dealing with the inevitable paravalvular leak (created by the ring deformation in the absence of valve-specific devices). Our case demonstrates that percutaneous tricuspid valve-in-ring replacement is a feasible treatment that can result in both hemodynamic and symptomatic improvement.

  8. Portable X-Ray Device


    Portable x-ray instrument developed by NASA now being produced commercially as an industrial tool may soon find further utility as a medical system. The instrument is Lixiscope - Low Intensity X-Ray Imaging Scope -- a self-contained, battery-powered fluoroscope that produces an instant image through use of a small amount of radioactive isotope. Originally developed by Goddard Space Flight Center, Lixiscope is now being produced by Lixi, Inc. which has an exclusive NASA license for one version of the device.

  9. Image-guided endoscopic spine surgery: Part I. A feasibility study.

    Assaker, R; Cinquin, P; Cotten, A; Lejeune, J P


    A feasibility study was performed to determine the efficacy of computer assistance in endoscopic spine surgery. To assess a new method for computer assistance based on image guidance during thoracoscopic or any endoscopic spine procedure. To evaluate the reproducibility, the sensitivity and the reliability of the technique first in vitro and second in clinical use. The computer-based, image-guided surgery is now a routine tool used in open spine surgery. Exposure of the anatomy of the vertebra is needed for registration. This methodology is inapplicable in endoscopic approach. Fluoroscopic-based navigation combines the technology of image-guided surgery and C-arm fluoroscopy. The navigation is based on the fluoroscopic images acquired before surgery. This technology is applicable to endoscopic surgery but the navigation is based on fluoroscopic image. The computed tomography images are not exploited. There are no published data on a technique that allows image-guided surgery based on computed tomography and magnetic resonance imaging. A laboratory study was performed on a thoracic human spine. One vertebra was marked on the right lateral side of the body with five titanium marks. A percutaneous reference frame was specifically designed to be placed in the pedicle of the same marked vertebrae. The reference frame acted as a 3D localizer and a registration tool. The spine model was scanned including the reference frame. A standard Stealth station treatment guidance platform (Medtronic, Sofamor Danek, Memphis, TN) was used for simulation. The registration was obtained using the reference frame. Twenty navigation procedure trials were done and the error was recorded based on the distance between the anatomical point and the corresponding virtual one. Registration was always possible using the stealth station and a standard spine navigational software (spine 3, Medtronic Sofamor Danek, Memphis, TN). The mean error after registration given by the computer was 0.96 mm

  10. The importance of phrenic nerve preservation and its effect on long-term postoperative lung function after pneumonectomy

    Kocher, Gregor J; Lysgaard, Jannie; Blichfeldt-Eckhardt, Morten Rune


    ) and fluoroscopic and/or sonographic assessment of diaphragmatic motion on the pneumonectomy side were performed before and after ultrasonographic-guided ipsilateral cervical phrenic nerve block by infiltration with lidocaine. RESULTS: Ipsilateral phrenic nerve block was successfully achieved in 12 patients (86......%). In the remaining 2 patients, diaphragmatic motion was already paradoxical before the nerve block. We found no significant difference on dynamic lung function values (FEV1 'before' 1.39 ± 0.44 vs FEV1 'after' 1.38 ± 0.40; P = 0.81). CONCLUSIONS: Induction of a temporary diaphragmatic palsy did not significantly...

  11. Radiation-Induced Alopecia after Endovascular Embolization under Fluoroscopy

    Vipawee Ounsakul


    Full Text Available Radiation-induced alopecia after fluoroscopically guided procedures is becoming more common due to an increasing use of endovascular procedures. It is characterized by geometric shapes of nonscarring alopecia related to the area of radiation. We report a case of a 46-year-old man presenting with asymptomatic, sharply demarcated rectangular, nonscarring alopecic patch on the occipital scalp following cerebral angiography with fistula embolization under fluoroscopy. His presentations were compatible with radiation-induced alopecia. Herein, we also report a novel scalp dermoscopic finding of blue-grey dots in a target pattern around yellow dots and follicles, which we detected in the lesion of radiation-induced alopecia.

  12. Exact focusing of extracorporeal shock wave therapy for calcifying tendinopathy.

    Haake, Michael; Deike, Barbara; Thon, Alexander; Schmitt, Jan


    A controlled prospective randomized study was designed to analyze the effect of extracorporeal shock wave therapy on calcifying tendinopathy of the shoulder focused on the calcified area or the origin of the supraspinatus tendon. Fifty patients were included in the study and were treated with a Storz Minilith Sl-1 shock wave generator. The first group of patients received 4000 impulses (positive energy flux density, 0.78 mJ/mm2) in two treatment sessions after receiving local anesthesia at the origin of the supraspinatus tendon. Patients in the second group received extracorporeal shock wave therapy at the calcified area. Follow-ups were done 12 weeks and 1 year after treatment by an independent observer. An increase of function and a reduction of pain occurred in both groups. Statistical analyses showed a significant superiority of extracorporeal shock wave application at the calcified area in the primary end point (Constant and Murley score). Therefore, exact fluoroscopic focusing of extracorporeal shock wave therapy at the calcific deposit for treatment of calcifying tendinopathy of the supraspinatus muscle is recommended. Based on these results, extracorporeal shock wave application should be focused fluoroscopically with appropriate shock wave generators.

  13. Flat-panel volume CT: fundamental principles, technology, and applications.

    Gupta, Rajiv; Cheung, Arnold C; Bartling, Soenke H; Lisauskas, Jennifer; Grasruck, Michael; Leidecker, Christianne; Schmidt, Bernhard; Flohr, Thomas; Brady, Thomas J


    Flat-panel volume computed tomography (CT) systems have an innovative design that allows coverage of a large volume per rotation, fluoroscopic and dynamic imaging, and high spatial resolution that permits visualization of complex human anatomy such as fine temporal bone structures and trabecular bone architecture. In simple terms, flat-panel volume CT scanners can be thought of as conventional multidetector CT scanners in which the detector rows have been replaced by an area detector. The flat-panel detector has wide z-axis coverage that enables imaging of entire organs in one axial acquisition. Its fluoroscopic and angiographic capabilities are useful for intraoperative and vascular applications. Furthermore, the high-volume coverage and continuous rotation of the detector may enable depiction of dynamic processes such as coronary blood flow and whole-brain perfusion. Other applications in which flat-panel volume CT may play a role include small-animal imaging, nondestructive testing in animal survival surgeries, and tissue-engineering experiments. Such versatility has led some to predict that flat-panel volume CT will gain importance in interventional and intraoperative applications, especially in specialties such as cardiac imaging, interventional neuroradiology, orthopedics, and otolaryngology. However, the contrast resolution of flat-panel volume CT is slightly inferior to that of multidetector CT, a higher radiation dose is needed to achieve a comparable signal-to-noise ratio, and a slower scintillator results in a longer scanning time.

  14. Novel High-Frequency Peripheral Nerve Stimulator Treatment of Refractory Postherpetic Neuralgia: A Brief Technical Note.

    Lerman, Imanuel R; Chen, Jeffrey L; Hiller, David; Souzdalnitski, Dmitri; Sheean, Geoffrey; Wallace, Mark; Barba, David


    The study aims to describe an ultrasound (US)-guided peripheral nerve stimulation implant technique and describe the effect of high-frequency peripheral nerve stimulation on refractory postherpetic neuralgia. Following a cadaver pilot trial using US and confirmatory fluoroscopic guidance, a 52-year-old man with refractory left supraorbital neuralgia underwent combined US and fluoroscopic-guided supraorbital peripheral nerve stimulator trial. The patient was subsequently implanted with a percutaneous lead over the left supraorbital and supratrochlear nerve utilizing a high-frequency stimulation paradigm. At 9 months follow-up, the pain intensity had declined from a weekly average of 8/10 to 1/10 on the pain visual analog scale (VAS). After implant, both nerve conduction and blink reflex studies were performed, which demonstrated herpetic nerve damage and frequency-specific peripheral nerve stimulation effects. The patient preferred analgesia in the supraorbital nerve distribution accomplished with high-frequency paresthesia-free stimulation (HFS) at an amplitude of 6.2 mA, a frequency of 100-1200 Hz, and a pulse width of 130 μsec, to paresthesia-mediated pain relief associated with low-frequency stimulation. We report the implant of a supraorbital peripheral nerve stimulating electrode that utilizes a high-frequency program resulting in sustained suppression of intractable postherpetic neuralgia. © 2015 International Neuromodulation Society.

  15. 2D-3D Registration of CT Vertebra Volume to Fluoroscopy Projection: A Calibration Model Assessment

    Allen R


    Full Text Available This study extends a previous research concerning intervertebral motion registration by means of 2D dynamic fluoroscopy to obtain a more comprehensive 3D description of vertebral kinematics. The problem of estimating the 3D rigid pose of a CT volume of a vertebra from its 2D X-ray fluoroscopy projection is addressed. 2D-3D registration is obtained maximising a measure of similarity between Digitally Reconstructed Radiographs (obtained from the CT volume and real fluoroscopic projection. X-ray energy correction was performed. To assess the method a calibration model was realised a sheep dry vertebra was rigidly fixed to a frame of reference including metallic markers. Accurate measurement of 3D orientation was obtained via single-camera calibration of the markers and held as true 3D vertebra position; then, vertebra 3D pose was estimated and results compared. Error analysis revealed accuracy of the order of 0.1 degree for the rotation angles of about 1 mm for displacements parallel to the fluoroscopic plane, and of order of 10 mm for the orthogonal displacement.

  16. A novel removable shield attached to C-arm units against scattered X-rays from a patient's side

    Mori, Hiroshige [Hokkaido Social Insurance Hospital, Department of Radiology, Sapporo, Hokkaido (Japan); Kanazawa University, Department of Quantum Medical Technology, Division of Health Sciences, Graduate School of Medical Science, Kanazawa, Ishikawa (Japan); Koshida, Kichiro; Matsubara, Kosuke [Kanazawa University, School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa, Ishikawa (Japan); Ishigamori, Osamu [Hokkaido Social Insurance Hospital, Department of Radiology, Sapporo, Hokkaido (Japan)


    We invented a drape-like shield against scattered X-rays that can safely come into contact with medical equipment or people during fluoroscopically guided procedures. The shield can be easily removed from a C-arm unit using one hand. We evaluated the use of the novel removable shield during the endoscopic retrograde cholangiopancreatography (ERCP) procedure. We measured the dose rate of scattered X-rays around endoscopists with and without this removable shield and surveyed the occupational doses to the ERCP staff. We also examined the endurance of the shield. The removable shield reduced the dose rate of scattered X-rays to one-tenth and reduced the monthly dose to an endoscopist by at least two-fifths. For 2.5 years, there was no damage to the shield and no loosening of the seam. The bonding of the hook-and-loop fasteners did not weaken, although the powerful double-sided tapes made especially for plastic did. The removable shield can reduce radiation exposure to the ERCP staff and may contribute to reducing the exposure to the eye lenses of operators. It would also be possible to expand its use to other fluoroscopically guided procedures besides ERCP because it is a light, simple, and useful device. (orig.)

  17. US-guided percutaneous transhepatic biliary drainage: comparative study of right-sided and left-sided approach

    Kim, Young Hwan; Cha, Soon Joo [College of Medicine, Inje Univ., Kimhae (Korea, Republic of)


    To compare the feasibility and safety of US-guided right and left percutaneous transhepatic biliary drainage (PTBD). Between March 1998 and May 1999, 32 patients underwent 36 US-guided right or left PTBD in referred order, alternatively. The causes of biliary obstruction were bile duct stone (n=2), bile duct carcinoma (n=10), carcinoma of the pancreas (n=9), GB carcinoma (n=7), metastasis to the porta hepatis (n=3), and carcinoma of the ampulla of vater (n=1). Technical success, procedure time, fluoroscopic time, and complications were evaluated. PTBD was successful in 94% of both right and left approach. The average procedure time was 9.7 {+-}3.8 min. in the right approach and 9.6 {+-}3.1 min. in the left approach, respectively (p=0.794). The average fluoroscopic time were 3.9{+-}2.4 min. in the right approach and 3.8{+-}2.2 min. in the left approach (p=0.892). A major complication, bile peritonitis, occurred in one of 16 patient with right-sided approach. Minor complications occurred in six right (2 hemobilia, 3 tube malfunction, 1 cholangitis) and three left (1 hemobilia, 1 fever, 1cholangitis) PTBD. There were no significant difference in the complication rates between right and left PTBD (p=0.729). There were no significant differences in feasibility and safety in US-guided right and left PTBD.

  18. Monoplane Stereoscopic Imaging Method for Inverse Geometry X-ray Fluoroscopy.

    Tomkowiak, Michael T; Van Lysel, Michael S; Speidel, Michael A


    Scanning Beam Digital X-ray (SBDX) is a low-dose inverse geometry fluoroscopic system for cardiac interventional procedures. The system performs x-ray tomosynthesis at multiple planes in each frame period and combines the tomosynthetic images into a projection-like composite image for fluoroscopic display. We present a novel method of stereoscopic imaging using SBDX, in which two slightly offset projection-like images are reconstructed from the same scan data by utilizing raw data from two different detector regions. To confirm the accuracy of the 3D information contained in the stereoscopic projections, a phantom of known geometry containing high contrast steel spheres was imaged, and the spheres were localized in 3D using a previously described stereoscopic localization method. After registering the localized spheres to the phantom geometry, the 3D residual RMS errors were between 0.81 and 1.93 mm, depending on the stereoscopic geometry. To demonstrate visualization capabilities, a cardiac RF ablation catheter was imaged with the tip oriented towards the detector. When viewed as a stereoscopic red/cyan anaglyph, the true orientation (towards vs. away) could be resolved, whereas the device orientation was ambiguous in conventional 2D projection images. This stereoscopic imaging method could be implemented in real time to provide live 3D visualization and device guidance for cardiovascular interventions using a single gantry and data acquired through normal, low-dose SBDX imaging.

  19. The role of the MR-fluoroscopy in the diagnosis and staging of the pelvic organ prolapse

    Etlik, Oemer E-mail:; Arslan, Halil; Odabasi, Oner; Odabasi, Hulya; Harman, Mustafa; Celebi, Hacer; Sakarya, M. Emin


    Introduction: The aim of the study is to investigate the efficacy of the magnetic resonance fluoroscopy in the diagnosis and staging of the pelvic prolapse. Materials and methods: The study consisted of 46 patients who were known to have pelvic prolapses from their vaginal examination. Thirty women who underwent vaginal exam and shown not have pelvic prolapse were selected as a control group. Firstly, pelvic sagittal FSE T2 weighted images of all the women were acquired in 0.3 T open MR equipment than sagittal MR-fluoroscopic images using spoiled gradient echo sequences were obtained during pelvic strain. Physical examination and MR-fluoroscopic findings were compared. The relationship between the stages of prolapse established by both of the methods was evaluated statistically with Pearson's correlation analysis. Results: Physical examination and MR findings were very concordant in the diagnosis of pelvic prolapse and statistical correlations in the stages of prolapse were established between both of the methods (P<0.01 for anterior and middle comportment, P<0.05 for posterior comportment). Conclusion: We conclude that MR-fluoroscopy is a non-invasive, easily applied, dynamic useful method without contrast agent in the diagnosis and staging of pelvic organ prolapse.

  20. Factors affecting radiation exposure during lumber epidural steroid injection: A prospective study in 759 patients

    Kim, Su Young; Lee, Joon Woo; Kang, Heung Sik; Lee, Guen Young; Ahn, Joong Mo [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Shin, Joon Ho [Dept. of Rehabilitation, National Rehabilitation Center, Seoul (Korea, Republic of)


    To estimate and compare radiation exposure and intervention time during lumbar epidural steroid injection (ESI) 1) under different practitioners and methods with continuous fluoroscopic monitoring, and 2) under one practitioner with different methods and monitoring. We consecutively recruited 804 patients who underwent lumbar ESI and 759 patients who underwent 922 interventions were included for analysis in this investigation. Three different practitioners (a senior faculty member, junior faculty member, trainee) performed lumbar ESI using different methods (caudal, interlaminar, transforaminal). The senior faculty member performed lumbar ESI under two different methods of fluoroscopic monitoring (continuous [CM] and intermittent monitoring [IM]). The dose area product (DAP) fluoroscopy time, and intervention time during lumbar ESI were compared for 1) ESI methods and practitioners under CM, and 2) ESI methods and monitoring. With CM, interaction between the effects of the practitioner and the intervention on DAP was significant (p < 0.001), but not fluoroscopy time (p = 0.672) or intervention time (p = 0.852). The significant main effects included the practitioner and intervention on DAP, fluoroscopy time, and intervention time with CM (p < 0.001). DAPs and fluoroscopy time for caudal, interlaminar, and transforaminal ESI were higher with CM than with IM (p < 0.001). Intervention time did not differ between CM and IM. Radiation exposure is dependent on the practitioners and methods and within the established safety limits during lumbar ESIs under CM. With an experienced practitioner, IM leads to less radiation exposure than CM.

  1. Visualization of cardiac wavefronts using data fusion

    Kynor, David B.; Dietz, Anthony; Friets, Eric; Peterson, Jon; Bergstrom, Ursula; Triedman, John; Hammer, Peter


    Catheter ablation has emerged as a highly effective treatment for arrhythmias that are constrained by known, easily located, anatomic landmarks. However, this treatment has enjoyed limited success for arrhythmias that are characterized by complex activation patterns or are not anatomically constrained. This class of arrhythmias, which includes atrial fibrillation and ventricular tachycardia resulting from ischemic heart disease, demands improved mapping tools. Current technology forces the cardiologist to view cardiac anatomy independently from the functional information contained in the electrical activation patterns. This leads to difficulties in interpreting the large volumes of data provided by high-density recording catheters and in mapping patients with abnormal anatomy (e.g., patients with congenital heart disease). The goal of this is work is development of new data processing and display algorithms that will permit the clinician to view activation sequences superimposed onto existing fluoroscopic images depicting the location of recording catheters within the heart. In cases where biplane fluoroscopic images and x-ray camera position data are available, the position of the catheters can be reconstructed in three-dimensions.

  2. Prosthetic Valve Thrombosis: Diagnosis and Management.

    Garg, Jalaj; Palaniswamy, Chandrasekar; Pinnamaneni, Sowmya; Sarungbam, Judy; Jain, Diwakar


    St. Jude mechanical prosthesis is the most commonly used prosthetic device with least valvular complications with excellent hemodynamics. However, prosthetic valve thrombosis is one of the serious complications, with rates between 0.03% and 0.13% per patient-year depending on the type of anticoagulation used and compliance to the therapy. Transthoracic echocardiography (TTE) is the initial screening tool (class I) that would provide clues for the assessment of valvular hemodynamics. Fluoroscopy is an alternate imaging modality for the assessment of mechanical leaflet motion, especially in patients when prosthetic valves are difficult to image on TTE or transesophageal echocardiography. A complete fluoroscopic evaluation of a prosthetic valve includes assessment of valvular motion and structural integrity. Opening and closing angles can be measured fluoroscopically to determine whether a specific valve is functioning properly. We discuss a case of a 91-year-old man with thrombosis of bileaflet mechanical mitral prosthesis that was demonstrated on real-time fluoroscopy (not evident on TTE). An algorithmic approach to diagnosis and management of prosthetic heart valve thrombosis is outlined.

  3. Fluoroscopy-Guided Percutaneous Gallstone Removal Using a 12-Fr Sheath in High-Risk Surgical Patients with Acute Cholecystitis

    Kim, Young Hwan [Keimyung University, College of Medicine, Daegu (Korea, Republic of); Kim, Yong Joo [Andong General Hospital, Andong (Korea, Republic of); Shin, Tae Beom [Gyeonsang National University, College of Medicine, Jinju (Korea, Republic of)


    To evaluate the technical feasibility and clinical efficacy of percutaneous transhepatic cholecystolithotomy under fluoroscopic guidance in high-risk surgical patients with acute cholecystitis. Sixty-three consecutive patients of high surgical risk with acute calculous cholecystitis underwent percutaneous transhepatic gallstone removal under conscious sedation. The stones were extracted through the 12-Fr sheath using a Wittich nitinol stone basket under fluoroscopic guidance on three days after performing a percutaneous cholecystostomy. Large or hard stones were fragmented using either the snare guide wire technique or the metallic cannula technique. Gallstones were successfully removed from 59 of the 63 patients (94%). Reasons for stone removal failure included the inability to grasp a large stone in two patients, and the loss of tract during the procedure in two patients with a contracted gallbladder. The mean hospitalization duration was 7.3 days for acute cholecystitis patients and 9.4 days for gallbladder empyema patients. Bile peritonitis requiring percutaneous drainage developed in two patients. No symptomatic recurrence occurred during follow-up (mean, 608.3 days). Fluoroscopy-guided percutaneous gallstone removal using a 12-Fr sheath is technically feasible and clinically effective in high-risk surgical patients with acute cholecystitis

  4. The learning curve of selective salpingography and tubal catheterization.

    Papaioannou, Spyros; Afnan, Masood; Girling, Alan J; Ola, Bolarinde; Hammadieh, Nehed; Coomarasamy, Aravinthan; Sharif, Kaldoun


    To determine the effect of increasing experience in fluoroscopically guided selective salpingography and tubal catheterization on radiation doses and screening times, thus establishing a learning curve for the procedure. Retrospective case note analysis. IVF center of an academic teaching hospital. Three hundred sixty-six patients with infertility seen over 3.5 years. Fluoroscopically guided selective salpingography and tubal catheterization. Reductions in radiation doses and screening times for different categories of selective salpingography and tubal catheterization, expressed as percentage reductions during the study period and reductions per 10 procedures. During the study period, The median dose of radiation decreased by 62.6%-71.9%, and the median screening time declined by 61.5%-78.5%. Reductions per 10 procedures were 2.5%-4.2% and 2.7%-5%, respectively. Significant reductions in radiation doses and screening times start early in a clinical team's practice of selective salpingography and tubal catheterization and continue even as trainees are added to the pool of operators.

  5. Fluoroscopy-guided intrA-articular facet joint steroid injection for the management of low back pain: Therapeutic effectiveness and arthrographic pattern

    Kim, Su Jin; Lee, Jun Woo; Lee, Guen Young; You, Ja Yeon; Kang, Heung Sik [Dept. of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Chai, Jae Won [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Ahn, Joong Mo [Dept. of Radiology, University of Pittsburgh Medical Center, Pittsburgh (United States)


    To evaluate the effectiveness of fluoroscopy-guided intra-articular facet joint steroid injection for the management of low back pain, and to document the incidence of epidural leakage. In total, 320 facet joint injections of 244 consecutive patients were included in this study. All patients had undergone an intra-articular facet joint steroid injection in 2007 and had follow-up post-treatment medical records. The response to treatment was analyzed on the basis of chart documentation (aggravated, no change, slightly improved, much improved, no pain). Fluoroscopic arthrograms of the injections were retrospectively analyzed by two radiologists. Of the 244 patients, 85.2% (n = 208) showed improvement after an initial intra-articular facet joint steroid injection. A total of 77.9% (n = 162) of the patients showed symptom recurrence, with a median of a 69 day symptom-free interval, while 30.3% (n = 74) of the patients showed symptom-free intervals of more than six months. Overall, 74 (33.3%) of the 222 cases of intra-articular facet joint steroid injections without concomitant epidural steroid injection showed epidural leakage in fluoroscopic arthrograms. Fluoroscopy-guided intra-articular facet joint injection is a reliable technique for the management of low back pain, with excellent immediate effectiveness and good prolonged (> 2 months) pain relief. Epidural leakage during injection was detected in one-third of the cases.

  6. Assessment of small bowel Crohn disease: noninvasive peroral CT enterography compared with other imaging methods and endoscopy--feasibility study.

    Wold, Peter B; Fletcher, Joel G; Johnson, C Daniel; Sandborn, William J


    A feasibility study was conducted to evaluate two biphasic computed tomographic (CT) enterography protocols, a noninvasive CT technique with water administered perorally and CT enteroclysis with methylcellulose administered through a nasojejunal tube, in 23 patients known or suspected to have Crohn disease. Results were compared with the results of fluoroscopic small bowel examination and terminal ileoscopy for the detection of active Crohn disease in the terminal ileum. Luminal distention did not differ significantly between the two CT protocols. Arterial phase imaging was noncontributory in 22 of 23 cases. The noninvasive peroral water CT enterography protocol had similar accuracy (12 of 15 cases, 80%) for enabling the detection of active Crohn disease in comparison with CT enteroclysis with nasojejunal tube (seven of eight, 88%) and fluoroscopic small bowel examination (17 of 23, 74%). No fistulas were missed with use of either CT technique. The authors conclude that noninvasive peroral portal venous phase CT enterography with use of water is an accurate and feasible technique for detecting active small bowel inflammation in patients with Crohn disease.

  7. Placement of an implantable central venous access device

    Kim, Tae Hoon; Lee, Young Suk [Dan Kook Univ., Seoul (Korea, Republic of). Hospital


    To evaluate the efficacy and safety of placement of a central venous catheter with infusion port into the superior vena cava. Central venous catheters with a infusion port were implanted in 21 patients (M:F=4:17, age range:15-63, mean age: 41) diagnosed as suffering from breast cancer (n=9), lymphoma (n=7), thymoma (n=2) rhabdomyosarcoma(n=2) and rectal cancer (n=1). The per(n=9), lymphoma(n=7), thymoma (n=2) rhabdomyosarcoma (n=2) and rectal cancer (n=1). The peripheral portion of the subclavian vein was punctured under fluoroscopic guidance during injection of contrast media at the site of the ipsilateral peripheral vein (20 cases) and under ultrasonographic guidance (1 case). 9.6F central venous catheters placed in the superior vena cava via the subclavian vein and the connected infusion ports were implanted in the subcutaneous pocket near the puncture site of the right anterosuperior chest wall. Radiologic placement under fluoroscopic guidance of a central venous catheter with a infusion port is easy, safe and useful for patients requiring long-term venous access. (author). 21 refs., 2 figs.


    Chandrashekhar V. Mudgal


    Full Text Available BACKGROUND A study was done to evaluate the effect of the ligamentotaxis in the management of intraarticular fractures of the distal radius. MATERIALS AND METHODS 34 patients were studied prospectively between March 2014 and February 2016. All patients had intraarticular fracture of distal end of radius and all were treated with ligamentotaxis after closed reduction with fluoroscopic guidance. The follow-up period was 12 months. At the time of surgery, the mean age was 45.29 years. RESULTS In all fracture cases, the mean of fracture union was 5.8 weeks. During the final follow-up, the mean range of motion was 55.30 in flexion, 56.60 in extension, 21.0 in ulnar deviation, 9.00 in radial deviation, 70.30 in pronation and 67.10 in supination. According to the scoring system of Gartland and Werley, the clinical and functional outcomes showed that 15 patients (44.1% had excellent results, 14 (41.1% had good results, 3 (8.8% had fair results and 2 (5.8% had poor results. CONCLUSION Closed reduction under fluoroscopic image guidance and the ligamentotaxis is useful and effective in the treatment of intraarticular fractures of the distal radius.

  9. The AAPM/RSNA physics tutorial for residents: fluoroscopy: optical coupling and the video system.

    Van Lysel, M S


    In fluoroscopic/fluorographic systems, an image intensifier is optically coupled to recording cameras. The optical distributor is responsible for transmitting a focused image from the output phosphor of the image intensifier to the focal planes of the cameras. Each camera has an aperture, which is used to control the level of light reaching its focal plane. The aperture setting determines the patient x-ray exposure level and the image noise level. Increasing the x-ray exposure reduces image noise; reducing the x-ray exposure increases image noise. Fluoroscopic/fluorographic systems always include a video camera. The functions of the video system are to provide for multiple observers and to facilitate image recording. The camera head contains an image sensor, which converts the light image from the image intensifier into a voltage signal. The device used to generate the video signal is a pickup tube or a charge-coupled device sensor. The method used is raster scanning, of which there are two types: progressive and interlaced. The vertical resolution of the system is primarily determined by the number of scan lines; the horizontal resolution is primarily determined by the bandwidth. Frame rate reduction can be a powerful tool for exposure reduction.

  10. Technical feasibility of 2D-3D coregistration for visualization of self-expandable microstents to facilitate coil embolization of broad-based intracranial aneurysms: an in vitro study

    Richter, Gregor [University of Erlangen-Nuernberg, Department of Neuroradiology, Erlangen (Germany); Kreisklinikum Siegen, Department of Radiology and Neuroradiology, Siegen (Germany); Pfister, Marcus [Siemens AG, Healthcare Sector, Forchheim (Germany); Struffert, Tobias; Engelhorn, Tobias; Doelken, Marc; Doerfler, Arnd [University of Erlangen-Nuernberg, Department of Neuroradiology, Erlangen (Germany); Spiegel, Martin; Hornegger, Joachim [University of Erlangen, Department of Informatics 5, Erlangen (Germany)


    The use of self-expandable microstents for treatment of broad-based intracranial aneurysms is widely spread. However, poor fluoroscopic visibility of the stents remains disadvantageous during the coiling procedure. Flat detector angiographic computed tomography (ACT) provides high resolution imaging of microstents even though integration of this imaging modality in the neurointerventional workflow has not been widely reported. An acrylic glass model was used to simulate the situation of a broad-based sidewall aneurysm. After insertion of a self-expandable microstent, ACT was performed. The resulting 3D dataset of the Microstent was subsequently projected into a conventional 2D fluoroscopic roadmap. This 3D visualization of the stent supported the coil embolization procedure of the in vitro aneurysm. In vitro 2D-3D coregistration with integration of 3D ACT data of a self-expandable microstent in a conventional 2D roadmap is feasible. Unsatisfying stent visibility constrains clinical cases with complex parent vessel anatomy and challenging aneurysm geometry; hence, this technique potentially may be useful in such cases. In our opinion, the clinical feasibility and utility of this new technique should be verified in a clinical aneurysm embolization study series using 2D-3D coregistration. (orig.)

  11. The effect of X-ray beam distortion on the Edwards Sapien XT(™) trans-catheter aortic valve replacement prosthesis.

    Crowhurst, James A; Poon, Karl K; Murdoch, Dale; Incani, Alexander; Raffel, Owen C; Liddicoat, Annelise; Walters, Darren


    Profiling the Aortic root perpendicular to the fluoroscopic image plane will achieve a more successful implant position for trans-catheter aortic valve replacement (TAVR). This study aimed to investigate whether the divergent nature of the X-ray beam from the C-arm altered the appearance of the TAVR device. Under bench-top testing, a 23, 26 and 29 mm Edwards Sapien XT valve was positioned coaxially at the bottom of a fluoroscopic image utilising 22 and 32 cm fields of view (FOV). The table was then moved so that the valve was positioned at the top of the image. The valve's appearance was scored using a previously published three tier classification tool (excellent, satisfactory and poor) and quantified with measurements. The number of degrees of C-arm rotation that were required to bring the valve back to a coaxial appearance was recorded. When using the 32 cm FOV, the valve's appearance changes from excellent to satisfactory. When a 22 cm FOV was used, the change is less marked. More C-arm rotation is required to bring the appearance back to coaxial with the 32 cm FOV. Not maintaining the valve in the centre of the image can distort the valves appearance. This has the potential to affect the final implantation depth.

  12. Placement of the AbbVie PEG-J tube for the treatment of Parkinson's disease in the interventional radiology suite

    Montgomery, Mark L.; Miner, Noel K.; Soileau, Michael J.


    The primary treatment for Parkinson's disease is dopaminergic stimulation. Although levodopa has historically been administered orally, maintaining a predictable plasma concentration of the drug is challenging. As a result, enteral administration of carbidopa/levodopa (Duopa) has emerged as a promising tool in the treatment of the disease. This requires placement of an enteric catheter, two of which have been approved by the Food and Drug Administration for delivery of Duopa. The approved tubes are placed using the “peroral” or “pull” technique, a method traditionally requiring endoscopy. This technical note describes placement of the AbbVie PEG-J tube by means of the peroral route while utilizing only sonographic and fluoroscopic guidance. After placing an orogastric tube and achieving percutaneous access to the stomach under fluoroscopic visualization, a snare catheter is advanced through the percutaneous access into the stomach. The orogastric tube is engaged with the snare and retracted, bringing the attached snare with it to the mouth. The AbbVie PEG tube is attached to the snare, pulled back down the esophagus and into the stomach before being retracted through the percutaneous access to the skin. Finally, the AbbVie J tube is advanced through the gastrostomy tube into the proximal jejunum and attached with the provided connectors. As demonstrated, the AbbVie PEG-J tube can be placed safely and effectively using a percutaneous image-guided technique without the use of an endoscope.

  13. Reproducibility of aortic annulus measurements by computed tomography

    Schuhbaeck, Annika; Achenbach, Stephan [University of Erlangen, Department of Cardiology, Erlangen (Germany); University of Giessen, Department of Cardiology, Giessen (Germany); Pflederer, Tobias; Marwan, Mohamed; Schmid, Jasmin; Arnold, Martin [University of Erlangen, Department of Cardiology, Erlangen (Germany); Nef, Holger; Rixe, Johannes; Hecker, Franziska [University of Giessen, Department of Cardiology, Giessen (Germany); Schneider, Christian [University of Giessen, Department of Radiology, Giessen (Germany); Lell, Michael; Uder, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany)


    To evaluate a systematic approach for measurement of aortic annulus dimensions by cardiac computed tomography. CT data sets of 64 patients were evaluated. An oblique cross-section aligned with the aortic root was created by systematically identifying the caudal insertion points of the three aortic cusps and sequentially aligning them in a double oblique plane. Aortic annulus dimensions, distances of coronary ostia and a suitable fluoroscopic projection angle were independently determined by two observers. Interobserver intraclass correlation coefficients (ICC) for aortic annulus diameters were excellent (ICC 0.89-0.93). Agreement for prosthesis size selection was excellent (k = 0.86 for mean, k = 0.84 for area-derived and k = 0.91 for circumference-derived diameter). Mean distances of the left/right coronary ostium were 13.4 ± 2.4/14.4 ± 2.8 mm for observer 1 and 13.2 ± 2.7/13.5 ± 3.2 mm for observer 2 (p = 0.30 and p = 0.0001, respectively; ICC 0.76/0.77 for left/right coronary artery). A difference of less than 10 for fluoroscopic projection angle was achieved in 84.3 % of patients. A systematic approach to generate a double oblique imaging plane exactly aligned with the aortic annulus demonstrates high interobserver and intraobserver agreements for derived measurements which are not influenced by aortic root calcification. (orig.)

  14. Treatment of pathologic spinal fractures with combined radiofrequency ablation and balloon kyphoplasty

    Tzanakakis George


    Full Text Available Abstract Background In oncologic patients with metastatic spinal disease, the ideal treatment should be well tolerated, relieve the pain, and preserve or restore the neurological function. The combination of fluoroscopic guided radiofrequency ablation (RFA and kyphoplasty may fulfill these criteria. Methods We describe three pathological vertebral fractures treated with a combination of fluoroscopic guided RFA and kyphoplasty in one session: a 62-year-old man suffering from a painful L4 pathological fracture due to a plasmocytoma, a 68-year-old man with a T12 pathological fracture from metastatic hepatocellular carcinoma, and a 71-year-old man with a Th12 and L1 pathological fracture from multiple myeloma. Results The choice of patients was carried out according to the classification of Tomita. Visual analog score (VAS and Oswestry disability index (ODI were used for the evaluation of the functional outcomes. The treatment was successful in all patients and no complications were reported. The mean follow-up was 6 months. Marked pain relief and functional restoration was observed. Conclusion In our experience the treatment of pathologic spinal fractures with combined radiofrequency ablation and balloon kyphoplasty is safe and effective for immediate pain relief in painful spinal lesions in neurologically intact patients.

  15. Technical feasibility of 2D-3D coregistration for visualization of self-expandable microstents to facilitate coil embolization of broad-based intracranial aneurysms: an in vitro study.

    Richter, Gregor; Pfister, Marcus; Struffert, Tobias; Engelhorn, Tobias; Doelken, Marc; Spiegel, Martin; Hornegger, Joachim; Doerfler, Arnd


    The use of self-expandable microstents for treatment of broad-based intracranial aneurysms is widely spread. However, poor fluoroscopic visibility of the stents remains disadvantageous during the coiling procedure. Flat detector angiographic computed tomography (ACT) provides high resolution imaging of microstents even though integration of this imaging modality in the neurointerventional workflow has not been widely reported. An acrylic glass model was used to simulate the situation of a broad-based sidewall aneurysm. After insertion of a self-expandable microstent, ACT was performed. The resulting 3D dataset of the Microstent was subsequently projected into a conventional 2D fluoroscopic roadmap. This 3D visualization of the stent supported the coil embolization procedure of the in vitro aneurysm. In vitro 2D-3D coregistration with integration of 3D ACT data of a self-expandable microstent in a conventional 2D roadmap is feasible. Unsatisfying stent visibility constrains clinical cases with complex parent vessel anatomy and challenging aneurysm geometry; hence, this technique potentially may be useful in such cases. In our opinion, the clinical feasibility and utility of this new technique should be verified in a clinical aneurysm embolization study series using 2D-3D coregistration.

  16. Development of an auxiliary system for the execution of vascular catheter interventions with a reduced radiological risk; system description and first experimental results.

    Placidi, Giuseppe; Franchi, Danilo; Marsili, Luca; Gallo, Pasquale


    Vascular catheterization is a common procedure in clinical medicine. It is normally performed by a specialist using an X-ray fluoroscopic guide and contrast-media. In the present paper, an image-guided navigation system which indicates a path providing guidance to the desired target inside the vascular tree is described with the aim of reducing the exposure of personnel and patients to X-rays during the catheterization procedure. A 3D model of the patient vascular tree, reconstructed with data collected by an angiography before starting the intervention, is used as a guide map instead of fluoroscopic scans. An accurate spatial correspondence between the body of the patient and the 3D reconstructed vascular model is established and, by means of a position indicator installed over the catheter tip, the real-time position/orientation of the tip is indicated correctly. This paper describes the system and the operational procedures necessary to use the proposed method efficiently during a catheter intervention. Preliminary experimental results on a phantom are also reported.

  17. Automatic system for measuring dose-area product (DAP) in ROI fluoroscopy

    Kezerashvili, M.; Bednarek, D.R.; Rudin, S. [Departments of Radiology and Biophysical Sciences, University at Buffalo, State University of New York, Buffalo, NY (United States)


    A computerized system for monitoring dose-area product (DAP) has been developed for region of interest (ROI) fluoroscopy in which patient exposure is reduced using an x-ray attenuating filter with an aperture. The system includes an IBM compatible computer which is connected through an IEEE-488 interface to an electrometer which measures the charge from a DAP ionization chamber. A digital input/output board connects the computer to the filter placement device to determine whether the filter is in or out of the beam, and to the x-ray generator to determine when the exposure is due to spot filming. The computer logs the DAP from conventional fluoroscopy, ROI fluoroscopy and spot filming separately, applying the appropriate calibration factor for each. Measured DAPs, fluoroscopic DAP rates and exposure times are displayed in real-time. The system has been installed in a GI fluoroscopic room so that the dose-reduction potential of ROI imaging can be evaluated. (author)

  18. A Simple Technique for Shoulder Arthrography

    Berna-Serna, J.D.; Redondo, M.V.; Martinez, F.; Reus, M.; Alonso, J.; Parrilla, A.; Campos, P.A. [Virgen de la Arrixaca Univ. Hospital, El Palmar, Murcia (Spain). Dept. of Radiology


    Purpose: To present a systematic approach to teaching a technique for arthrography of the shoulder. Using an adhesive marker-plate with radiopaque coordinates, precise sites for puncture can be identified and the need for fluoroscopic guidance obviated. Material and Methods: Forty-six glenohumeral arthrograms were performed in 45 patients; in 1 case involving examination of both shoulders. The stages of the technique are described in detail, as are the fundamental aspects of achieving an effective glenohumeral injection. Pain intensity was measured in all patients using a verbal description scale. Results: Shoulder arthrography was successful in all cases. Average time taken for the procedure was 7 min, with no difference in the respective times required by an experienced radiologist and a resident. The procedure was well tolerated by most patients, with slight discomfort being observed in a very few cases. Conclusion: The arthrographic technique used in this study is simple, safe, rapid, and reproducible, and has the advantage of precise localization of the site for puncture without need for fluoroscopic guidance. The procedure described in this study can be of help in teaching residents and can reduce the learning curve for radiologists with no experience in arthrographic methods. It also reduces the time of exposure to fluoroscopy Keywords: Arthrography, joint, shoulder.

  19. W.S.B.--a fluoroscopy C-arm communication strategy.

    Williams, Timothy H D; Syrett, Amanda G; Brammar, Timothy J


    Good communication between an operating clinician and the attending radiographer when using C-arm fluoroscopy is vital. Efficient and safe use of ionising radiation protects all theatre staff. The object of this study was to design and test a single communication language for use in all fluoroscopy-assisted procedures. A clinician guiding a radiographer performed a control 'no-rules' experiment of 56 targeting manoeuvres with a fluoroscopic C-arm on a scientific model. A single beam laser replaced the usual ionising radiation beam. The time taken for each targeting along with the laser exposure required was recorded. Following a period of instruction, the experiment was repeated using only our pre-defined communication strategy. The data was collected for statistical analysis. A statistically significant reduction was seen in the time taken for each targeting manoeuvre and the laser exposure required when using our strategy. This study shows that using our pre-prepared communication strategy could significantly improve efficiency and safety of fluoroscopic C-arm use.

  20. Why are important the quality control measurements in x-ray equipment; Por que sao importantes as medicoes de controle de qualidade em equipamentos de raios X ?

    Dias Rodrigues, B.B., E-mail: [Secretaria de Saude do Distrito Federal, Brasilia, DF (Brazil). Diretoria de Engenharia Clinica e Equipamentos Medicos. Supervisao de Radioprotecao; Oliveira da Silva, M.W.; Canevaro, L.V., E-mail:, E-mail: [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)


    In this work tests were used for quality control fluoroscopic units dedicated to interventional cardiology in three institutions of Rio de Janeiro. We evaluated four equipment, two belonging to a public hospital and two other to private hemodynamic services. The results obtained during the tests to assess the field size and the rate of air kerma at the entrance of the patient are presented. All devices evaluated showed the size of the field within the limits except an equipment of national fabrication of a public institution. The recommended values for air kerma rate at the entrance of the patient were also exceeded in institutions evaluated. This work shows the importance of maintaining the X-ray tube as far as possible the patient to maintain a constant focus distance - intensifier. In addition to dose reduction and obtaining adequate image quality it is necessary to submit the fluoroscopic equipment to a program of quality control. It is essential to educate professionals in the sense that the methods of protection of the patient almost always result in decreased doses of professionals.

  1. 3D multimodality roadmapping in neuroangiography

    Ruijters, Daniel; Babic, Drazenko; Homan, Robert; Mielekamp, Peter; ter Haar Romeny, Bart M.; Suetens, Paul


    In this paper we describe a novel approach to using morphological datasets (such as CT or MR) in the minimally invasive image guidance of intra-arterial and intra-venous endovascular devices in neuroangiography interventions. Minimally invasive X-ray angiography procedures rely on the navigation of endovascular devices, such as guide wires and catheters, through human vessels, using C-arm fluoroscopy. While the bone structure may be visible, and the injection of iodine contrast medium allows to guide endovascular devices through the vasculature, the soft-tissue structures remain invisible in the fluoroscopic images. We intend to present a method for the combined visualization of morphological data, a 3D rotational angiography (3DRA) reconstruction and the live fluoroscopy data stream in a single image. The combination of the fluoroscopic image with the 3DRA vessel tree offers the advantage that endovascular devices can be located with respect to the vasculature, without additional contrast injection, while the position of the C-arm geometry can be altered freely. The additional visualization of the morphological data, adds contextual information to the position of endovascular devices. This article addresses the clinical applications, the real-time aspects of the registration algorithms and fast fused visualization of the proposed method.

  2. 3D roadmap in neuroangiography: technique and clinical interest

    Soederman, Michael; Andersson, T. [Karolinska Hospital, Department of Neuroradiology, Stockholm (Sweden); Babic, D.; Homan, R. [Philips Medical Systems, Best (Netherlands)


    We present the first clinical results obtained with a novel technique: the three-dimensional [3D] roadmap. The major difference from the standard 2D digital roadmap technique is that the newly developed 3D roadmap is based on a rotational angiography acquisition technique with the two-dimensional [2D] fluoroscopic image as an overlay. Data required for an accurate superimposition of the previously acquired 3D reconstructed image on the interactively made 2D fluoroscopy image, in real time, are stored in the 3D workstation and constitute the calibration dataset. Both datasets are spatially aligned in real time; thus, the 3D image is accurately superimposed on the 2D fluoroscopic image regardless of any change in C-arm position or magnification. The principal advantage of the described roadmap method is that one contrast injection allows the C-arm to be positioned anywhere in the space and allows alterations in the distance between the x-ray tube and the image intensifier as well as changes in image magnification. In the clinical setting, the 3D roadmap facilitated intravascular neuronavigation with concurrent reduction of procedure time and use of contrast medium. (orig.)

  3. The impact of radiological equipment on patient radiation exposure during endovascular aortic aneurysm repair

    Fossaceca, Rita; Guzzardi, Giuseppe; Cerini, Paolo; Carriero, Alessandro [University Hospital ' ' Maggiore della Carita' ' , Radiology Department, Novara (Italy); Brambilla, Marco; Valzano, Serena [University Hospital ' ' Maggiore della Carita' ' , Medical Physics Department, Novara (Italy); Renghi, Alessandra; Brustia, Piero [University Hospital ' ' Maggiore della Carita' ' , Vascular Surgery Department, Novara (Italy)


    To compare the patient radiation dose during endovascular aortic aneurysm repair (EVAR) using different types of radiological systems: a mobile fluoroscopic C-arm, mobile angiographic and fixed angiographic equipment. Dose-area products (DAP) were obtained from a retrospective study of 147 consecutive patients, subjected to 153 EVAR procedures during a 3.5-year period. On the basis of these data, entrance surface dose (ESD) and effective dose (ED) were calculated. EVARs were performed using a fluoroscopic C-arm, mobile or fixed angiographic equipment in 79, 26 and 48 procedures, respectively. Fluoroscopy times were essentially equivalent for all the systems, ranging from 15 to 19 min. The clinical outcomes were not significantly different among the systems. Statistically significant differences among radiological equipment grouping were found for DAP (mobile C-arm: 32 {+-} 20 Gy cm{sup 2}; mobile angiography: 362 {+-} 164 Gy cm{sup 2}; fixed angiography: 464 {+-} 274 Gy cm{sup 2}; P < 10{sup -6}), for ESD (mobile C-arm: 0.18 {+-} 0.11 Gy; mobile angiography: 2.0 {+-} 0.8 Gy; fixed angiography: 2.5 {+-} 1.5 Gy; P < 10{sup -6}) and ED (mobile C-arm: 6.2 {+-} 4.5 mSv; mobile angiography: 64 {+-} 26 mSv; fixed angiography: 129 {+-} 76 mSv; P < 10{sup -6}). Radiation dose in EVAR is substantially less with a modern portable C-arm than with a fixed or mobile dedicated angiographic system. (orig.)

  4. Hardware accelerated C-arm CT and fluoroscopy: a pilot study

    Riabkov, Dmitri; Brown, Todd; Cheryauka, Arvi; Tokhtuev, Alexander


    Clinical demands of image-guided procedures present technical challenges in X-ray 1K×1K fluoroscopy and cone-beam CT on a mobile C-arm. Performance-per-watt and performance-per-dollar are other major considerations in a search for an optimal computational platform. Real-time constraints of processing high-resolution fluoroscopic images currently necessitate the use of highly specialized proprietary image processing hardware, which cannot be easily repurposed for acceleration of other computing tasks. In our previous studies, we were investigating heterogeneous computing architectures and suitable hardware/software components to assist in time-critical surgical applications. Through those studies, it has been shown that Graphics Processing Units (GPUs) can provide outstanding levels of computational power utilizing the Single Instruction Multiple Data (SIMD) programming model. In the present study, we expand our research in the domain of real-time processing and continue to explore the feasibility of GPU acceleration for both fluoroscopic and tomographic imaging. Current emphasis is being placed on applicability of NVIDIA's novel Tesla computing solutions and Compute Unified Device Architecture (CUDA). The results of this pilot project comprise the Cg/OpenGL and CUDA algorithm implementations, benchmark evaluations, and examples of processing image data acquired with use of anthropomorphic phantoms.

  5. First steps towards initial registration for electrophysiology procedures

    Brost, Alexander; Bourier, Felix; Yatziv, Liron; Koch, Martin; Hornegger, Joachim; Strobel, Norbert; Kurzidim, Klaus


    Atrial fibrillation is the most common heart arrhythmia and a leading cause of stroke. The treatment option of choice is radio-frequency catheter ablation, which is performed in electrophysiology labs using C-Arm X-ray systems for navigation and guidance. The goal is to electrically isolate the pulmonary vein-left atrial junction thereby rendering myocardial fibers responsible for induction and maintenance of AF inactive. The use of overlay images for fluoroscopic guidance may improve the quality of the ablation procedure, and can reduce procedure time. Overlay images, acquired using CT, MRI, or C-arm CT, can add soft-tissue information, otherwise not visible under X-ray. MRI can be used to image a wide variety of anatomical details without ionizing radiation. In this paper, we present a method to register a 3-D MRI volume to 2-D biplane X-ray images using the coronary sinus. Current approaches require registration of the overlay images to the fluoroscopic images to be performed after the trans-septal puncture, when contast agent can be administered. We present a new approach for registration to align overlay images before the trans-septal puncture. To this end, we manually extract the coronary sinus from pre-operative MRI and register it to a multi-electorde catheter placed in the coronary sinus.

  6. MR arthrography of the shoulder: tolerance evaluation of four different injection techniques

    Perdikakis, Evangelos; Drakonaki, Eleni; Karantanas, Apostolos [University Hospital, Department of Medical Imaging, Heraklion, Crete (Greece); Maris, Thomas [University Hospital, Department of Medical Physics, Heraklion, Crete (Greece)


    We sought to prospectively evaluate patients' pain perception and technical success of four different arthrographic techniques for shoulder MR arthrography. A total of 125 consecutive patients were referred for shoulder MR arthrography. The patients were randomly injected under fluoroscopic guidance (n{sub 1} = 37), with CT guidance using an anterior (n{sub 2} = 29) or a posterior approach (n{sub 3} = 32) and with ultrasound guidance (n{sub 4} = 27). For each patient, absolute periprocedural pain on a numerical rating pain scale (0 = ''no pain'', 10 = ''intolerable pain''), technical success of the method used, and reason for referral were recorded. The technical success rate was 100 % for all injection methods. The results regarding absolute periprocedural pain were as follows: fluoroscopic guidance showed a mean pain of 4.05 {+-} 1.24, CT anterior guidance demonstrated a mean pain of 3.87 {+-} 0.95, CT posterior guidance showed a mean pain of 1.59 {+-} 0.81, and ultrasound guidance a mean pain of 3.63 {+-} 1.12. A significant difference (p <.05) was observed for the posterior route under CT guidance. The mean pain level was significantly higher for older (> 51 year) female patients. No differences were found for the technical success rate of the aforementioned techniques. A CT-guided posterior approach seems to be a more comfortable method for the patient. (orig.)

  7. [Effectiveness of lead thyroid shield for reducing roentgen ray exposure in trauma surgery interventions of the lower leg].

    Müller, L P; Suffner, J; Mohr, W; Degreif, J; Rommens, P M


    The occupational radiation exposure of trauma surgeons has increased over the last few years as a result of biologic orthopaedic procedures like intramedullary nailing as closed reduction and insertion of distal interlocking screws need fluoroscopic control. In order to assess the surface doses of the primary surgeon with and without lead shield of the thyroid we performed in vitro measurements during operative procedures of the lower extremities simulating different intraoperative situations under fluoroscopic control. The average registered ionizing dosage without thyroid shield was 70 times higher compared to the measurements with thyroid protection. In a previous study we found average fluoroscopy times during intramedullary nailing of tibia and femur of 4.6 min per procedure. Extrapolation of this value leads to the result, that even when 1000 intramedullary nailings were carried out without wearing lead protection, 13% of the dose limit recommended by the International Commission on Radiological Protection for the thyroid of 300 mSv per year would not be exceeded, whereas by wearing the lead protection only 0.2% of the recommended dose would be reached.

  8. Magnetic resonance imaging urodynamics: technique development and preliminary results

    Gustavo Borghesi


    Full Text Available OBJECTIVES: In this preliminary study we report the development of the video urodynamic technique using magnetic resonance imaging (MRI. MATERIALS AND METHODS: We studied 6 women with genuine stress urinary incontinence, diagnosed by history and physical examination. Urodynamic examination was performed on multichannel equipment with the patient in the supine position. Coughing and Valsalva maneuvers were performed at volumes of 150, 250 and 350 mL. Simultaneously, MRI was carried out by using 1.5 T GE Signa CV/i high-speed scanner with real time fluoroscopic imaging possibilities. Fluoroscopic imaging was accomplished in the corresponding planes with T2-weighted single shot fast spin echo sequences at a speed of about 1 frame per second. Both studies were recorded and synchronized, resulting in a single video urodynamic examination. RESULTS: Dynamic MRI with cine-loop reconstruction of 1 image per second demonstrated the movement of all compartment of the relaxed pelvis during straining with the concomitant registration of abdominal and intravesical pressures. In 5 patients, urinary leakage was demonstrated during straining and the Valsalva leak point pressure (VLPP was determined as the vesical pressure at leak subtracted from baseline bladder pressure. Mean VLPP was 72.6 cm H2O (ranging from 43 to 122 cm H2O. CONCLUSIONS: The concept of MRI video urodynamics is feasible. In a clinical perspective, practical aspects represent a barrier to daily use and it should be recommended for research purposes.

  9. Initial clinical experience using the Echo Navigator~-system during structural heart disease interventions

    Jan; Balzer; Tobias; Zeus; Katharina; Hellhammer; Verena; Veulemans; Silke; Eschenhagen; Eva; Kehmeier; Christian; Meyer; Tienush; Rassaf; Malte; Kelm


    AIM: To present our initial clinical experience using this innovative software solution for guidance of percutaneous structural heart disease interventions.METHODS: Left atrial appendage, atrial septal defect and paravalvular leak closure, transaortic valve repair and Mitra Clip procedures were performed in the catheter laboratory under fluoroscopic and echocardiographic guidance. The two-dimensional and three-dimensional images generated by the transesophageal echocardiography probe were interfaced with the fluoroscopic images in real-time using the Echo Navigator-system.RESULTS:The application of the novel image fusion technology was safe and led to a better appreciation of multimodality imaging guidance due to improved visualization of the complex relationship between catheter devices and anatomical structures.CONCLUSION:The Echo Navigator-system is a feasible and safe tool for guidance of interventional procedures in structural heart disease.This innovative technology may improve confidence of interventional cardiologists in targeting and positioning interventional devices in order to increase safety,accuracy,and efficacy of percutaneous interventions in the catheter laboratory.

  10. Accuracy of Posterior Subtalar Joint Injection Without Fluoroscopy

    Kirk, Kevin L.; Campbell, John T.; Guyton, Gregory P.


    Injection into the posterior subtalar joint has not been validated for accuracy using radiographic end points. We asked whether needle placement into a normal posterior subtalar joint could be performed accurately and selectively by experienced surgeons without fluoroscopic guidance. Three fellowship-trained orthopaedic foot and ankle surgeons each injected the posterior subtalar joint of 20 cadaveric specimens using an anterolateral approach. Fluoroscopic images were obtained by an independent investigator and blinded. A separate fellowship-trained foot and ankle surgeon interpreted the images. Of 60 injections, 58 were accurate and two were extraarticular based on interpretation by an independent foot and ankle surgeon. Extravasation into the ankle occurred in 14 samples and into the peroneal sheath in two samples. Experienced surgeons can place intraarticular injections into a radiographically normal posterior subtalar joint without fluoroscopy with a high degree of accuracy. However, extravasation into the ankle or peroneal tendon sheath occurred in an unpredictable fashion, suggesting selectivity of injection placement is relatively limited without the use of fluoroscopy. Fluoroscopy may not be necessary for injections used solely for therapeutic purposes. However, if the injection is intended for diagnostic purposes or to assist in surgical decision-making or if the joint is abnormal, we recommend fluoroscopy to ensure the subtalar joint is the only anatomic structure impacted by the injection. PMID:18404293

  11. Factors affecting the accuracy of endoscopic transpapillary sampling methods for bile duct cancer.

    Nishikawa, Takao; Tsuyuguchi, Toshio; Sakai, Yuji; Sugiyama, Harutoshi; Tawada, Katsunobu; Mikata, Rintaro; Tada, Motohisa; Ishihara, Takeshi; Miyazaki, Masaru; Yokosuka, Osamu


    Various methods for endoscopic transpapillary sampling have been developed. However, the factors affecting the accuracy of these methods for bile duct cancer are unknown. The aim of the present study was to determine the factors affecting the accuracy of endoscopic transpapillary sampling methods. We reviewed the results from 101 patients with bile duct cancer who underwent transpapillary sampling by aspiration bile cytology, brushing cytology, and fluoroscopic forceps biopsy. The final diagnosis of bile duct cancer was made on the basis of pathological evaluation of specimens obtained at surgery and the clinical course over at least 1 year in patients not operated on. We carried out subgroup analyses for the factors affecting the accuracy of each transpapillary sampling method. Aspiration bile cytology was carried out 238 times in 77 patients, brushing cytology was carried out 67 times in 60patients, and fluoroscopic forceps biopsy was carried out 64 times in 53 patients. Accuracies of aspiration bile cytology were significantly higher for longer (≥15 mm) biliary cancerous lesions than for shorter (sampling methods are more accurate for longer or elevated (non-flat) biliary cancerous lesions than for shorter or flat lesions. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

  12. Successful enteral nutrition in the treatment of esophagojejunal fistula after total gastrectomy in gastric cancer patients

    Portanova Michel


    Full Text Available Abstract Background Esophagojejunal fistula is a serious complication after total gastrectomy in gastric cancer patients. This study describes the successful conservative management in 3 gastric cancer patients with esophagojejunal fistula after total gastrectomy using total enteral nutrition. Methods Between January 2004 to December 2008, 588 consecutive patients with a proven diagnosis of gastric cancer were taken to the operation room to try a curative treatment. Of these, 173 underwent total gastrectomy, 9 of them had esophagojejunal fistula (5.2%. In three selected patients a trans-anastomotic naso-enteral feeding tube was placed under fluoroscopic vision when the fistula was clinically detected and a complete polymeric enteral formula was used. Results The complete closing of the esophagojejunal fistula was obtained in day 8, 14 and 25 respectively. Conclusion In some selected cases it is possible to make a successful enteral nutrition using a feeding tube distal to the leak area inserted with the help of fluoroscopic vision. The specialized management of a gastric surgery unit and nutritional therapy unit are highlighted.

  13. Effectiveness of combined use of imprint cytological and histological examination in CT-guided tissue-core biopsy

    Yamagami, Takuji; Yoshimatsu, Rika; Kajiwara, Kenji; Ishikawa, Masaki; Awai, Kazuo [Hiroshima University, Department of Diagnostic Radiology, Institute and Graduate School of Biomedical Sciences, Minami-Ku, Hiroshima (Japan); Matsumoto, Tomohiro; Hasebe, Terumitsu [Tokai University Hachioji Hospital, Tokai University School of Medicine, Department of Radiology, Hachioji, Tokyo (Japan); Kakizawa, Hideaki [Hiroshima University, Department of Diagnostic Radiology, Institute and Graduate School of Biomedical Sciences, Minami-Ku, Hiroshima (Japan); Hiroshima Red Cross Hospital and Atomic-bomb Survivors Hospital, Department of Diagnostic Radiology, Naka-Ku, Hiroshima (Japan); Toyoda, Naoyuki [Hiroshima University, Department of Diagnostic Radiology, Institute and Graduate School of Biomedical Sciences, Minami-Ku, Hiroshima (Japan); National Hospital Organisation Kure Medical Centre, Department of Diagnostic Radiology, Kure, Hiroshima (Japan)


    This study evaluated the efficacy of the combination of imprint cytology and histology in tissue-core percutaneous biopsy under real-time computed tomography (CT) fluoroscopic guidance. Between October 2009 and June 2013, 156 percutaneous needle biopsies were performed in our institution. Those obtained by tissue-core biopsy underwent both imprint cytological and histological examinations routinely after touch imprint cytology was performed on site to evaluate the samples' sufficiency for cytological and pathological examination. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up. Rates of adequate specimens and precise diagnosis, by combined cytological and histological examination were 100 % (156/156) and 96.2 % (150/156), by cytology 94.4 % (152/156) and 83.3 % (130/156) and by histology 99.3 % (155/156) and 92.3 % (144/156). Precise diagnosis was achieved by combined examinations in 94.7 % (89/94) of thoracic lesions, 97.6 % (40/41) of musculoskeletal lesions, and 100 % (21/21) of abdominal, pelvic and retroperitoneal lesions. In all 104 lesions diagnosed as malignant by CT-guided biopsy and in 30 of 52 diagnosed as benign, specific cell types could be proved by combined examinations. Combined imprint cytology and histology performed after on-site touch imprint cytological evaluation improved the diagnostic ability of CT fluoroscopically guided biopsy. (orig.)

  14. Fecal microbiota transplantation via fluoroscopy-guided nasojejunal catheter placement: indications, technique, and the role of radiology.

    Wonderlick, Julien S; D'Agostino, Robert


    Clostridium difficile is a well-established cause of nosocomial gastrointestinal disease. Although antibiotics remain an effective first-line treatment for C. difficile colitis (CDC), relapse and recurrence are common. FMT has emerged as one of the safest and most effective known therapies available for recurrent or refractory CDC, which is likely due to restoration of the protective microbiotic barrier of the gastrointestinal tract. FMT varies greatly across institutions by route of delivery, dose, and protocol. We present our experience with FMT via fluoroscopic-guided nasojejunal catheter placement. The discussion will include indications and contraindications, protocol, and procedural technique, and include a case presentation incorporating original CT and fluoroscopic images. Specifically, we will address the advantages and disadvantages of image-guided FMT via the upper GI tract with respect to nasogastric-, colonoscopic-, and enema-based delivery. The efficacy of FMT for the treatment of C. difficile has been widely demonstrated in several prospective and case studies. We feel that nasojejunal FMT is an underutilized radiologic procedure which can benefit selected patients, particularly given the advantages in risk profile, cost, convenience, and lack of routine sedation.

  15. Investigation of grid performance using simple image quality tests

    Dogan Bor


    Full Text Available Antiscatter grids improve the X-ray image contrast at a cost of patient radiation doses. The choice of appropriate grid or its removal requires a good knowledge of grid characteristics, especially for pediatric digital imaging. The aim of this work is to understand the relation between grid performance parameters and some numerical image quality metrics for digital radiological examinations. The grid parameters such as bucky factor (BF, selectivity (Σ, Contrast improvement factor (CIF, and signal-to-noise improvement factor (SIF were determined following the measurements of primary, scatter, and total radiations with a digital fluoroscopic system for the thicknesses of 5, 10, 15, 20, and 25 cm polymethyl methacrylate blocks at the tube voltages of 70, 90, and 120 kVp. Image contrast for low- and high-contrast objects and high-contrast spatial resolution were measured with simple phantoms using the same scatter thicknesses and tube voltages. BF and SIF values were also calculated from the images obtained with and without grids. The correlation coefficients between BF values obtained using two approaches (grid parameters and image quality metrics were in good agreement. Proposed approach provides a quick and practical way of estimating grid performance for different digital fluoroscopic examinations.

  16. Combined MV + kV inverse treatment planning for optimal kV dose incorporation in IGRT

    Grelewicz, Zachary; Wiersma, Rodney D.


    Despite the existence of real-time kV intra-fractional tumor tracking strategies for many years, clinical adoption has been held back by concern over the excess kV imaging dose cost to the patient when imaging in continuous fluoroscopic mode. This work aims to solve this problem by investigating, for the first time, the use of convex optimization tools to optimally integrate this excess kV imaging dose into the MV therapeutic dose in order to make real-time kV tracking clinically feasible. Phase space files modeling both a 6 MV treatment beam and a kV on-board-imaging beam of a commercial LINAC were generated with BEAMnrc, and used to generate dose influence matrices in DOSXYZnrc for ten previously treated lung cancer patients. The dose optimization problem for IMRT, formulated as a quadratic problem, was modified to include additional constraints as required for real-time kV intra-fractional tracking. An interior point optimizer was used to solve the modified optimization problem. It was found that when using large kV imaging apertures during fluoroscopic tracking, combined MV + kV optimization lead to a 0.5%-5.17% reduction in the total number of monitor units assigned to the MV beam due to inclusion of the kV dose over the ten patients. This was accompanied by a reduction of up to 42% of the excess kV dose compared to standard MV IMRT with kV tracking. For all kV field sizes considered, combined MV + kV optimization provided prescription dose to the treatment volume coverage equal to the no-imaging case, yet superior to standard MV IMRT with non-optimized kV fluoroscopic tracking. With combined MV + kV optimization, it is possible to quantify in a patient specific way the dosimetric effect of real-time imaging on the patient. Such information is necessary when substantial kV imaging is performed.

  17. C-arm positioning using virtual fluoroscopy for image-guided surgery

    de Silva, T.; Punnoose, J.; Uneri, A.; Goerres, J.; Jacobson, M.; Ketcha, M. D.; Manbachi, A.; Vogt, S.; Kleinszig, G.; Khanna, A. J.; Wolinsky, J.-P.; Osgood, G.; Siewerdsen, J. H.


    Introduction: Fluoroscopically guided procedures often involve repeated acquisitions for C-arm positioning at the cost of radiation exposure and time in the operating room. A virtual fluoroscopy system is reported with the potential of reducing dose and time spent in C-arm positioning, utilizing three key advances: robust 3D-2D registration to a preoperative CT; real-time forward projection on GPU; and a motorized mobile C-arm with encoder feedback on C-arm orientation. Method: Geometric calibration of the C-arm was performed offline in two rotational directions (orbit α, orbit β). Patient registration was performed using image-based 3D-2D registration with an initially acquired radiograph of the patient. This approach for patient registration eliminated the requirement for external tracking devices inside the operating room, allowing virtual fluoroscopy using commonly available systems in fluoroscopically guided procedures within standard surgical workflow. Geometric accuracy was evaluated in terms of projection distance error (PDE) in anatomical fiducials. A pilot study was conducted to evaluate the utility of virtual fluoroscopy to aid C-arm positioning in image guided surgery, assessing potential improvements in time, dose, and agreement between the virtual and desired view. Results: The overall geometric accuracy of DRRs in comparison to the actual radiographs at various C-arm positions was PDE (mean ± std) = 1.6 ± 1.1 mm. The conventional approach required on average 8.0 ± 4.5 radiographs spent "fluoro hunting" to obtain the desired view. Positioning accuracy improved from 2.6o ± 2.3o (in α) and 4.1o ± 5.1o (in β) in the conventional approach to 1.5o ± 1.3o and 1.8o ± 1.7o, respectively, with the virtual fluoroscopy approach. Conclusion: Virtual fluoroscopy could improve accuracy of C-arm positioning and save time and radiation dose in the operating room. Such a system could be valuable to training of fluoroscopy technicians as well as

  18. Estudo de otimização de imagens em fluoroscopia intervencionista Study of optimization of images in interventional fluoroscopy

    Alexandre Parizoti


    Full Text Available OBJETIVO: O objetivo deste trabalho é o de estudar a otimização da qualidade da imagem fluoroscópica e a taxa de kerma no ar de entrada na superfície do paciente em procedimentos de radiologia intervencionista, utilizando-se de um objeto simulador adaptado para fluoroscopia. MATERIAIS E MÉTODOS: Foi utilizado um objeto simulador desenvolvido para avaliação de imagens em radiologia convencional. O objeto simulador foi adaptado para fluoroscopia mediante incorporação de dois cateteres com diferentes espessuras, ambos utilizados em radiologia intervencionista. Os níveis de taxa de kerma no ar de entrada na superfície do paciente foram determinados utilizando-se este objeto simulador. RESULTADOS: A avaliação dos parâmetros técnicos para diversos modos de exposição de um equipamento fluoroscópico com digitalização de imagens permitiu estabelecer os indicadores de taxa de kerma no ar, que permitem a otimização da qualidade das imagens em procedimentos intervencionistas. A redução na taxa de kerma no ar de entrada na superfície do paciente pode chegar a 67%. CONCLUSÃO: A otimização da qualidade da imagem utilizando-se um objeto simulador possibilita reduzir a taxa de kerma no ar de entrada na superfície do paciente, sem perda considerável de informação diagnóstica.OBJECTIVE: The objective of the present study is to analyze the optimization of fluoroscopic image quality and patient entrance surface air kerma rate in interventional radiology procedures, utilizing a phantom adapted for fluoroscopy. MATERIALS AND METHODS: The authors utilized a phantom developed for evaluating conventional radiological images adapted for fluoroscopy through the addition of two catheters with different diameters, both of them utilized in interventional radiology. The patient entrance surface air kerma rate was determined with the aid of this phantom. RESULTS: The evaluation of technical parameters for different exposure modes of a digital

  19. Closed-form inverse kinematics for interventional C-arm X-ray imaging with six degrees of freedom: modeling and application.

    Wang, Lejing; Fallavollita, Pascal; Zou, Rui; Chen, Xin; Weidert, Simon; Navab, Nassir


    For trauma and orthopedic surgery, maneuvering a mobile C-arm fluoroscope into a desired position to acquire an X-ray is a routine surgical task. The precision and ease of use of the C-arm becomes even more important for advanced interventional imaging techniques such as parallax-free X-ray image stitching. Today's standard mobile C-arms have been modeled with only five degrees of freedom (DOF), which definitely restricts their motions in 3-D Cartesian space. In this paper, we present a method to model both the mobile C-arm and patient's table as an integrated kinematic chain having six DOF without constraining table position. The closed-form solutions for the inverse kinematics problem are derived in order to obtain the required values for all C-arm joint and table movements to position the fluoroscope at a desired pose. The modeling method and the closed-form solutions can be applied to general isocentric or nonisocentric mobile C-arms. By achieving this we develop an efficient and intuitive inverse kinematics-based method for parallax-free panoramic X-ray imaging. In addition, we implement a 6-DOF C-arm system from a low-cost mobile fluoroscope to optimally acquire X-ray images based solely on the computation of the required movement for each joint by solving the inverse kinematics on a continuous basis. Through simulation experimentation, we demonstrate that the 6-DOF C-arm model has a larger working space than the 5-DOF model. C-arm repositioning experiments show the practicality and accuracy of our 6-DOF C-arm system. We also evaluate the novel parallax-free X-ray stitching method on phantom and dry bones. Using five trials, results show that parallax-free panoramas generated by our method are of high visual quality and within clinical tolerances for accurate evaluation of long bone geometry (i.e., image and metric measurement errors are less than 1% compared to ground-truth).

  20. Clinical outcomes following spinal fusion using an intraoperative computed tomographic 3D imaging system.

    Xiao, Roy; Miller, Jacob A; Sabharwal, Navin C; Lubelski, Daniel; Alentado, Vincent J; Healy, Andrew T; Mroz, Thomas E; Benzel, Edward C


    OBJECTIVE Improvements in imaging technology have steadily advanced surgical approaches. Within the field of spine surgery, assistance from the O-arm Multidimensional Surgical Imaging System has been established to yield superior accuracy of pedicle screw insertion compared with freehand and fluoroscopic approaches. Despite this evidence, no studies have investigated the clinical relevance associated with increased accuracy. Accordingly, the objective of this study was to investigate the clinical outcomes following thoracolumbar spinal fusion associated with O-arm-assisted navigation. The authors hypothesized that increased accuracy achieved with O-arm-assisted navigation decreases the rate of reoperation secondary to reduced hardware failure and screw misplacement. METHODS A consecutive retrospective review of all patients who underwent open thoracolumbar spinal fusion at a single tertiary-care institution between December 2012 and December 2014 was conducted. Outcomes assessed included operative time, length of hospital stay, and rates of readmission and reoperation. Mixed-effects Cox proportional hazards modeling, with surgeon as a random effect, was used to investigate the association between O-arm-assisted navigation and postoperative outcomes. RESULTS Among 1208 procedures, 614 were performed with O-arm-assisted navigation, 356 using freehand techniques, and 238 using fluoroscopic guidance. The most common indication for surgery was spondylolisthesis (56.2%), and most patients underwent a posterolateral fusion only (59.4%). Although O-arm procedures involved more vertebral levels compared with the combined freehand/fluoroscopy cohort (4.79 vs 4.26 vertebral levels; p fusion only (HR 0.39; p fusion (HR 0.22; p = 0.03), but not posterior/transforaminal lumbar interbody fusion. CONCLUSIONS To the authors' knowledge, the present study is the first to investigate clinical outcomes associated with O-arm-assisted navigation following thoracolumbar spinal fusion. O

  1. Development of a real-time in-vivo dose guided radiotherapy system

    Ushino, T.; Smith, M.; Perle, S. [Global Dosimetry Solutions, Irvine, CA (United States); Justus, B.; Huston, A.; Falkenstein, P. [U. S. Naval Research Lab., Optical Physics Branch, Washington, DC (United States); Miller, R.; Coleman, N. [National Cancer Institute, National Institutes of Health, Bethesda, MD (United States)


    Accurately assessing the dose to target organs and surrounding tissues in radiation therapy is paramount to achieving maximum treatment efficacy. The goal of radiation therapy is to deliver an optimum dose of ionizing radiation to the target area while at the same time, minimizing the dose to the surrounding tissues. Frequently the target tissue is spatially dynamic and is in close proximity to other tissues whose radiation dose should be minimized to avoid damage. A highly spatially resolved real-time patient dosimetry system will allow radiation therapists and physicians to verify, instantaneously, that the radiation dose is being delivered accurately to the intended target area. There also is a need to accurately assess skin dose in real-time during fluoroscopically-guided interventional procedures to minimize skin damage. A substantial increase in the number of fluoroscopically guided interventional procedures since the 1990 has resulted in an increase in the incidence of radiation-induced skin injuries. This has become a concern to the extent that F.D.A. proposed regulations for monitoring radiation doses delivered by fluoroscopy machines(1). The most likely cause of radiation induced skin injuries are due to particularly long procedures performed at normal dose rates. The availability of real-time radiation dose information will allow the operating physician to appropriately balance the clinical benefit of enhanced visualization versus radiation risks associated with long interventional procedures. Global Dosimetry Solutions (G.D.S.), Inc., a fully accredited world-wide provider of dosimetry services to a wide range of customers including hospitals, medical and dental offices, veterinary clinics, university and national laboratories, nuclear power plants, etc., has developed an in vivo, real-time radiation monitoring technologies for use in radiotherapy and fluoroscopically-guided procedures. The core technologies were developed by Drs. Brian Justus and Alan

  2. Percutaneous peritoneovenous shunt positioning: technique and preliminary results

    Orsi, Franco; Grasso, Rosario Francesco; Bonomo, Guido; Marinucci, Irene [Division of Radiology, European Institute of Oncology, Milan (Italy); Monti, Cinzia [Institute of Radiology, University of Milan (Italy); Bellomi, Massimo [Division of Radiology, European Institute of Oncology, Milan (Italy); Institute of Radiology, University of Milan (Italy)


    Nine peritoneovenous shunts were positioned by percutaneous technique in seven patients with advanced malignancy causing severe refractory ascites, and in two patients with hepatic cirrhosis (one with hepatocarcinoma). In all patients the shunts were percutaneously placed through the subclavian vein in the angiographic suite under digital fluoroscopic guide. No complications directly related to the procedure occurred. The shunt was successfully positioned in all patients in 60 min average time. No patient showed symptoms related to pulmonary overload or to disseminated intravascular coagulation. All patients had a significant improvement of the objective symptoms related to ascites such as respiratory symptoms, dyspepsia, and functional impairment to evacuation describing an improvement of their quality of life. Maximum shunt patency was 273 days. Percutaneous placement of peritoneovenous shunt is a safe, fast, and inexpensive procedure, extremely useful in resolution of refractory ascites, reducing symptoms, and allowing effective palliation, with a great improvement in quality of life. (orig.)

  3. Cervicogenic headache: an assessment of the evidence on clinical diagnosis, invasive tests, and treatment.

    Bogduk, Nikolai; Govind, Jayantilal


    Cervicogenic headache is characterised by pain referred to the head from the cervical spine. Although the International Headache Society recognises this type of headache as a distinct disorder, some clinicians remain sceptical. Laboratory and clinical studies have shown that pain from upper cervical joints and muscles can be referred to the head. Clinical diagnostic criteria have not proved valid, but a cervical source of pain can be established by use of fluoroscopically guided, controlled, diagnostic nerve blocks. In this Review, we outline the basic science and clinical evidence for cervicogenic headache and indicate how opposing approaches to its definition and diagnosis affect the evidence for its clinical management. We provide recommendations that enable a pragmatic approach to the diagnosis and management of probable cervicogenic headache, as well as a rigorous approach to the diagnosis and management of definite cervical headache.

  4. Treatment of osteoporotic vertebral body compression fractures by percutaneous vertebroplasty

    Hongmin Zang; Yiheng Liu; Junchang Chen


    Objective: To explore the effect of percutaneous vertebroplasty to treat osteoporotic vertebral body compression fractures. Methods: Seventeen patients with compression fractures at 27 different levels came in for percutaneous vertebroplasty. Under the guidance of C-arm image intensifier, bone needle was inserted into the fracture vertebral bodies via a unilateral transpedicular approach.Polymethyl methacrylate (PMMA) was injected slowly under continuous fluoroscopic control. Then the effect was evaluated after operation.Results: Follow-up results among 15 patients were studied, other two patients lost contact. The follow-up period was from three to seven months. No patient had relapse of compression fracture. Leakage of the cement outside the vertebral body was seen in four bodies. All patients had a complete relief after Percutaneous vertebroplasty(PVP). Conclusion: PVP is an efficient minimally invasive technique to treat osteoporotic vertebral body compression fractures.

  5. Radiologically placed tunneled peritoneal catheter in palliation of malignant ascites

    Akinci, Devrim; Erol, Bekir; Ciftci, Tuerkmen T. [Hacettepe University, Faculty of Medicine, Department of Radiology, 06100 Ankara (Turkey); Akhan, Okan, E-mail: [Hacettepe University, Faculty of Medicine, Department of Radiology, 06100 Ankara (Turkey)


    The purpose of this study was to evaluate retrospectively the safety and effectiveness of radiologically placed tunneled peritoneal catheter in palliation of malignant ascites. Between July 2005 and June 2009, 41 tunneled peritoneal catheters were placed under ultrasonographic and fluoroscopic guidance in 40 patients (mean age, 55 years; 22 women) who had symptomatic malignant ascites. No procedure related mortality was observed. Major complication occurred in one patient (2.5%) in the form of serious bacterial peritonitis that necessitated catheter removal. Minor complications such as minor bacterial peritonitis, catheter dislodgement, tunnel infection, and catheter blockage occurred in 11 patients (27.5%). The mean duration of survival after catheter placement was 11.8 weeks. All patients expired of their primary malignancies in the follow-up. Radiologically placed tunneled peritoneal catheter is safe and effective in palliation of symptomatic malignant ascites.

  6. Management of pudendal neuralgia using ultrasound-guided pulsed radiofrequency: a report of two cases and discussion of pudendal nerve block techniques.

    Hong, Myong-Joo; Kim, Yeon-Dong; Park, Jeong-Ki; Hong, Hyon-Joo


    Pudendal neuralgia is characterized by chronic pain or discomfort in the area innervated by the pudendal nerve, with no obvious cause. A successful pudendal nerve block is crucial for the diagnosis of pudendal neuralgia. Blind or fluoroscopy-guided pudendal nerve blocks have been conventionally used for diagnosis and treatment; however, ultrasound-guided pudendal nerve blocks were also reported recently. With regard to the achievement of long-term effects, although pulsed radiofrequency performed under fluoroscopic guidance has been reported, that performed under ultrasound guidance is not well reported. This report describes two cases of pudendal neuralgia that were successfully managed using ultrasound-guided pulsed radiofrequency and presents a literature review of pudendal nerve block techniques. However, in the management of chronic neuropathic pain, physicians should keep in mind that the placebo effect related to invasive approaches must not be neglected.

  7. In vivo determination of total knee arthroplasty kinematics

    Komistek, Richard D [ORNL; Mahfouz, Mohamed R [ORNL; Bertin, Kim [Utah Bone & Joint Center, Salt Lake City, Utah (USA); Rosenberg, Aaron [Rush-Presbyterian-St. Luke' s Med Center, Chicago IL (USA); Kennedy, William [Kennedy-White Orthopaedic Center, Sarasota, FL (USA)


    The objective of this study was to determine if consistent posterior femoral rollback of an asymmetrical posterior cruciate retaining (PCR) total knee arthroplasty was mostly influenced by the implant design, surgical technique, or presence of a well-functioning posterior cruciate ligament (PCL). Three-dimensional femorotibial kinematics was determined for 80 subjects implanted by 3 surgeons, and each subject was evaluated under fluoroscopic surveillance during a deep knee bend. All subjects in this present study having an intact PCL had a well-functioning PCR knee and experienced normal kinematic patterns, although less in magnitude than the normal knee. In addition, a surprising finding was that, on average, subjects without a PCL still achieved posterior femoral rollback from full extension to maximum knee flexion. The findings in this study revealed that implant design did contribute to the normal kinematics demonstrated by subjects having this asymmetrical PCR total knee arthroplasty.

  8. Contemporary pediatric gynecologic imaging.

    Servaes, Sabah; Victoria, Teresa; Lovrenski, Jovan; Epelman, Monica


    Ultrasound is the primary screening modality for the evaluation of pediatric gynecologic maladies. Magnetic resonance imaging (MRI) is used progressively more in this field, particularly for the evaluation of complex pelvic masses and congenital anomalies. However, ultrasound remains the preferred modality due to the excellent visualization, the dynamic nature of the examination modality, lack of ionizing radiation and sedation risks, and comparatively lower cost. MRI is generally a second-line examination and is preferred over computed tomography as it does not involve the use of ionizing radiation. Additionally, visualization of the female reproductive system anatomy with MRI is superior to computed tomography, the latter being reserved generally for tumor staging. Fluoroscopic examinations and abdominal radiographs can provide additional information that may support a diagnosis. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  9. The apoptosis of HEL cells induced by hydroxyures



    Hydroxyurea has been used to synchronize cultured cells to S-phase and used to treat patients with sicklecell anemia.Recently,we found that hydroxyurea can induce the apoptosis of HEL(human erythroleukemia) cells.The induced HEL cells showed ultrastructurally chromatin condensation with regular crescents at the nuclear edges and apoptotic bodies.However,the cells of K562,another human erythroleukemia cell line,did not show such morphological changes.Under fluoroscope,the HEL cells after induction of ten displayed a clear reduction in nuclear diameter and nuclear chromatin cleavage and condensation and the presence of nuclear ring and apoptotic bodies.Analysis with flow cytometry showed that the percentage of apoptotic cells is about 30-40% after HEL cells were induced by hydroxyurea for 3 days.DNA ladder can be observed by electrophoretic analysis.

  10. Salter-Harris type II metacarpal and metatarsal fracture in three foals. Treatment by minimally-invasive lag screw osteosynthesis combined with external coaptation.

    Klopfenstein Bregger, Micaël D; Fürst, Anton E; Kircher, Patrick R; Kluge, Katharina; Kummer, Martin


    To describe minimally-invasive lag screw osteosynthesis combined with external coaptation for the treatment of Salter-Harris type II third metacarpal and third metatarsal bone fractures. Three foals aged two weeks to four months with a Salter-Harris type II third metacarpal or third metatarsal fracture. Surgery was carried out under general anaesthesia in lateral recumbency. After fracture reduction, the metaphyseal fragment was stabilized with two cortical screws placed in lag fashion under fluoroscopic control. A cast was applied for at least two weeks. All foals had a good outcome with complete fracture healing and return to complete soundness without any angular limb deformity. All foals had moderate transient digital hyperextension after cast removal. Internal fixation of Salter-Harris type II third metacarpal or third metatarsal fractures with two cortical screws in lag fashion, combined with external coaptation provided good stabilization and preserved the longitudinal growth potential of the injured physis.

  11. [Treatment of acute scapholunate ligament tears with simple wiring and arthroscopic assistance].

    Mathoulin, C; Messina, J


    Scapholunate ligament tears give chronic instability leading in SLAC. The wrist arthroscopy allows to see the lesions, even in early stage, and to treat them, with a simple K-Wires fixation in acute cases. The patients were operated on in outpatient basis with tourniquet and local general anaesthesia. In acute cases, the scapholunate dissociation was reduced by external and internal manoeuvres. The fixation was done with two pins under arthroscopic and fluoroscopic controls. We report a series of 66 acute cases (less than 45 days after trauma). Forty-four patients were males and 22 females. The average age was 39 years old (range 19-46). Our average follow-up in acute cases was 36 months (range 14-61). According the "Mayo Wrist Score", we obtained 92 % of good or excellent results. The wrist arthroscopy is the best technique for early diagnosis, guarantee of best functional results.

  12. Entrapment of Guide Wire in an Inferior Vena Cava Filter: A Technique for Removal

    Abdel-Aal, Ahmed Kamel, E-mail:; Saddekni, Souheil [University of Alabama at Birmingham, Department of Radiology (United States); Hamed, Maysoon Farouk [University of Alabama at Birmingham, Department of Anesthesia (United States); Fitzpatrick, Farley [Radiology Specialists of Louisville (United States)


    Entrapment of a central venous catheter (CVC) guide wire in an inferior vena cava (IVC) filter is a rare, but reported complication during CVC placement. With the increasing use of vena cava filters (VCFs), this number will most likely continue to grow. The consequences of this complication can be serious, as continued traction upon the guide wire may result in filter dislodgement and migration, filter fracture, or injury to the IVC. We describe a case in which a J-tipped guide wire introduced through a left subclavian access without fluoroscopic guidance during CVC placement was entrapped at the apex of an IVC filter. We describe a technique that we used successfully in removing the entrapped wire through the left subclavian access site. We also present simple useful recommendations to prevent this complication.

  13. A Feasibility Study into the Use of Three-Dimensional Printer Modelling in Acetabular Fracture Surgery

    A. W. Yu


    Full Text Available There are a number of challenges associated with the operative treatment of acetabular fractures. The approach used is often extensive, while operative time and perioperative blood loss can also be significant. With the proliferation of 3D printer technology, we present a fast and economical way to aid the operative planning of complex fractures. We used augmented stereoscopic 3D CT reconstructions to allow for an appreciation of the normal 3D anatomy of the pelvis on the fractured side and to use the models for subsequent intraoperative contouring of pelvic reconstruction plates. This leads to a reduction in the associated soft tissue trauma, reduced intraoperative time and blood loss, minimal handling of the plate, and reduced fluoroscopic screening times. We feel that the use of this technology to customize implants, plates, and the operative procedure to a patient’s unique anatomy can only lead to improved outcomes.

  14. Case study: Gluteal compartment syndrome as a cause of lumbosacral radiculoplexopathy and complex regional pain syndrome.

    Lederman, Andrew; Turk, David; Howard, Antonio; Reddy, Srinivas; Stern, Michelle


    We present the case of a 24 yr old male who was diagnosed with gluteal compartment syndrome and was subsequently found to have developed lumbosacral radiculoplexopathy and complex regional pain syndrome. The patient's gluteal compartment syndrome was diagnosed within 24 h of presentation to the emergency room, and he underwent emergent compartment release. While recovering postoperatively, persistent weakness was noted in the right lower limb. Results of electrodiagnostic testing were consistent with a lumbosacral radiculoplexopathy. After admission to inpatient rehabilitation, the patient complained of pain, burning sensation, and numbness in the distal right lower limb. Based on clinical findings, he was diagnosed with complex regional pain syndrome type II, or causalgia, and was referred for a lumbar sympathetic block under fluoroscopic guidance. Sympathetic block resulted in relief of the patient's symptoms. He was discharged home with good pain control on oral medications.

  15. The Use Of A Digital Store To Provide Pulsed Fluoroscopy And Stored Images During Gastro-Intestinal Examinations

    Hynes, D. M.; Edmonds, E. W.; Rowlands, J. A.; Pack, W. W.


    A 512 X 512 digital store has replaced a video disc as a storage mechanism during pulsed fluoroscopy. This system, storing 1 TV field from a 1023 line signal following each pulse, is much more stable than the analog disc and can also reduce the fluoroscopic dose by 75%. This stability now makes the concept of pulsed fluoroscopy acceptable from the clinical point of view. Furthermore, the stored images on this matrix can resolve to 1.5 line pairs per mm, which produces useful permanent hard copy. This represents a further extension of clinical videofluorography, already developed by the authors. Its implementation for storage of gastro-intestinal examinations will be discussed, with assessment of the relationship of x-ray dose to image quality.

  16. Ureteroscopy for treatment of upper urinary tract stones in children: technical considerations.

    Gupta, Natasha; Ko, Joan; Matlaga, Brian R; Wang, Ming-Hsien


    The incidence of pediatric urolithiasis is increasing. While many smaller stones may pass spontaneously, surgical therapy is sometimes warranted. Surgical options include shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy, and open surgery. Ureteroscopy represents a minimally invasive approach, and it is increasingly being used to treat pediatric upper tract calculi. Ureteroscopy is performed under anesthesia and fluoroscopic guidance, with basket extraction or lithotripsy of the calculi. Technical considerations include active or passive ureteral dilatation, the use of ureteral access sheaths for larger stone burdens, and post-operative stent placement. The current pediatric literature suggests high success rates (equal to or surpassing shock wave lithotripsy) and low complication rates. However, concerns remain regarding feasibility in patients with variant anatomies and risk due to intra-operative radiation exposure.

  17. CT scan-guided percutaneous osteosynthesis of a complex, multifocal fracture of the pelvic girdle in a 14-year-old adolescent

    Gagne, Pierre-Thomas; Bertrand, Anne-Sophie; Caudal, Amandine; El Hayek, Tony; Amoretti, Nicolas [Centre Hospitalier Universitaire de Nice, Nice (France)


    We report on a 14-year-old girl with minimally displaced pelvic girdle and acetabular roof fracture following motor vehicle trauma, treated percutaneously under CT and C-arm fluoroscopic guidance by an interventional radiologist. After informed consent from the patient's parents, under surgical aseptic conditions and under general anesthesia, three screws were positioned adequately under dual guidance by a radiologist and without immediate or long-term complication. The patient was mobilized 48 h after the procedure and resumed normal activities after 1 month. Even though the technique has been described before on adults, to our knowledge this is the first time it has been described on a pediatric patient. (orig.)

  18. A case of uveitis due to Rickettsia conorii infection in Southeastern France.

    Caisso, Cecile; Payan, Jacques; Dunais, Brigitte; Neri, Dominique; Vassallo, Matteo


    We describe a case of skin rash and bilateral uveitis secondary to Rickettsia conorii infection. A 60-year-old female patient, living in the rural hinterland of Cannes, was referred to our hospital in mid-August 2012 for skin rash, fever, and arthromyalgia. Blood tests showed increased inflammatory markers, hepatic cytolysis and anicteric cholestasis. Ophthalmic examination revealed bilateral papillitis and focal chorio-retinitis. Fluoroscopic angiography demonstrated early hypofluorescence, with a few arteriolar occlusions, and subsequent hyperfluorescence and focal vasculitis. R. conorii antibodies were identified by immunofluorescence antibody test. Investigation of other infective agents and the immunological panel were negative. A 2-week course of doxycycline 200 mg/day was prescribed, and fever rapidly subsided, the skin rash resolved and vision improved. Ophthalmic examination a month and a half later showed almost all retinal lesions had disappeared and inflammation markers had returned to normal. Copyright © 2015 Elsevier GmbH. All rights reserved.

  19. National data analysis of general radiography projection method in medical imaging

    Kim, Jung Su; Seo, Deok Nam; Choi, In Seok [Dept. of Bio-Convergence Engineering, Korea University Graduate School, Seoul (Korea, Republic of); and others


    According to database of medical institutions of health insurance review and assessment service in 2013, 1,118 hospitals and clinics have department of radiology in Korea. And there are CT, fluoroscopic and general radiographic equipment in those hospitals. Above all, general radiographic equipment is the most commonly used in the radiology department. And most of the general radiographic equipment are changing the digital radiography system from the film-screen types of the radiography system nowadays. However, most of the digital radiography department are used the film-screen types of the radiography system. Therefore, in this study, we confirmed present conditions of technical items for general radiography used in hospital and research on general radiographic techniques in domestic medical institutions. We analyzed 26 radiography projection method including chest, skull, spine and pelvis which are generally used in the radiography department.

  20. Medical interventional procedures--reducing the radiation risks

    Cousins, C. E-mail:; Sharp, C


    Over the last 40 years, the number of percutaneous interventional procedures using radiation has increased significantly, with many secondary care clinicians using fluoroscopically guided techniques. Many procedures can deliver high radiation doses to patients and staff, with the potential to cause immediate and delayed radiation effects. The challenge for interventionists is to maximize benefit, whilst minimizing radiation risk to patients and staff. Non-radiologist clinicians are often inadequately trained in radiation safety and radiobiology. However, clinical governance and legislation now requires a more rigorous approach to protecting patients and staff. Protection can be ensured, and risks can be controlled, by appropriate design, procurement and commissioning of equipment; quality assurance; and optimal operational technique, backed by audit. Interventionists need knowledge and skills to reduce the risks. Appropriate training should include awareness of the potential for radiation injury, equipment operational parameters, doses measurement and recording methods and dose reduction techniques. Clinical governance requires informed consent, appropriate patient counselling and follow-up.

  1. Radiological follow-up of uncemented knee prostheses. Preliminary study. Seguimiento radiologico de protesis de rodilla no cementadas. Estudio preliminar

    Martin Hervas, C.; Gomez Barrena, E.; Marquez Moreno, I.; Calle Yuste, F.; Ordoez Parra, J.M.


    The preliminary results of a prospective study of 40 uncemented total knee prostheses (TKP) are presented following a radiological protocol with fluoroscopic control and follow-up of over 2 years. The prosthesis-bone interface and the components alignment were assessed. Several radiological signs were studied to assess this interface with respect to the fixing of the component, but they showed little clinical correlation. Statistical significance (p<0.05, chisquare) was found only in the observation of sclerosis in areas of support for the tibital tray as a reaction of the bone. This radiological follow-up is of interest to determine the evolution of the interface and position of the implant to prevent complications (especially loosening) in patients, particularly those under 60 years old, who represent the group that can most benefit from prosthetic systems with uncemented anchorage because of their life expectation and level of activity. Author

  2. Short-term assessment of periradicular corticosteroid injections in lumbar radiculopathy associated with disc pathology

    Viton, J.M.; Rubino, T.; Delarque, A. [Departement Universitaire de Reeducation et Readaptation, Marseille (France); Peretti-Viton, P.; Salamon, N. [Service de Neuroradiologie, C. H. U. de la Timone, 264 Rue Saint-Pierre, F-13385 Marseille Cedex 05 (France)


    We evaluated periradicular injection of corticosteroids performed by neuroradiologists under fluoroscopic guidance in the treatment of lumbosacral nerve root pain in 40 patients (average age 48 years) presenting with lumbosciatica or radiculopathy not responding to conservative treatment. Patients with root pain due to infectious, neoplastic or inflammatory diseases were excluded, as were patients who needed immediate surgery. Pain was evaluated using a visual analogue scale (VAS) 10 and 90 days after the injection. After 10 days a substantial decrease in root pain was observed, with a statistically significant decrease in mean VAS. This decrease was observed in 90 % of patients, and it persisted after 90 days in 85 %. Side effects were rare, mild and disappeared spontaneously. They were related to the drug injected (corticosteroids). (orig.) With 2 figs., 3 tabs., 24 refs.

  3. Tulip deformity with Cera atrial septal defect devices: a report of 3 cases.

    Kohli, Vikas


    Device closure of secundum atrial septal defect (ASD) is the treatment of choice when anatomy is favourable. Amplatzer device has remained the gold standard for closure of ASD. Cobra deformity is a well-reported problem with devices. Recently, Tulip deformity has been reported in a single case. We report a series of cases where we noted Tulip deformity along with inability to retract the device in the sheath in Cera Lifetech devices. This resulted in prolongation of procedure, excessive fluoroscopic exposure and additional interventional procedures not usually anticipated in ASD device closure. We believe that the problem is due to the stiffness of the device resulting in its inability to be retracted into the sheath. We also report a unique way of retrieving the device.

  4. Patient exposure and radiation environment of an extracorporeal shock wave lithotriptor system

    Lin, P.J.; Hrejsa, A.F.


    Radiation exposures to the patient undergoing extracorporeal shock wave lithotripsy were assessed along with the scattered radiation levels around the lithotriptor systems. The data gathered from 2 Dornier lithotriptor systems suggest that the lead shieldings required for this particular make and model are minimal. Owing to the physical size of the lithotriptor system, the treatment room housing it may not require additional lead shielding when the walls are constructed with appropriate materials. Typical radiation exposures to the patient have been assessed from the experimental data. The total amount of radiation exposures a patient is likely to receive has been estimated to be approximately 26 roentgens, for example 21 roentgens from 3 to 4 minutes of fluoroscopic exposure and 5 roentgens from 8 frames of video spot filming. The scattered radiation has been found to be approximately 0.5 mR. per hour at 3 feet or 91 cm. from the center of the lithotriptor water tank.

  5. Application of image fusion techniques in DSA

    Ye, Feng; Wu, Jian; Cui, Zhiming; Xu, Jing


    Digital subtraction angiography (DSA) is an important technology in both medical diagnoses and interposal therapy, which can eliminate the interferential background and give prominence to blood vessels by computer processing. After contrast material is injected into an artery or vein, a physician produces fluoroscopic images. Using these digitized images, a computer subtracts the image made with contrast material from a series of post injection images made without background information. By analyzing the characteristics of DSA medical images, this paper provides a solution of image fusion which is in allusion to the application of DSA subtraction. We fuse the images of angiogram and subtraction, in order to obtain the new image which has more data information. The image that fused by wavelet transform can display the blood vessels and background information clearly, and medical experts gave high score on the effect of it.

  6. Endoscope-guided pneumatic dilation for treatment of esophageal achalasia

    Chuah, Seng-Kee; Wu, Keng-Liang; Hu, Tsung-Hui; Tai, Wei-Chen; Changchien, Chi-Sin


    Pneumatic dilation (PD) is considered to be the first line nonsurgical therapy for achalasia. The principle of the procedure is to weaken the lower esophageal sphincter by tearing its muscle fibers by generating radial force. The endoscope-guided procedure is done without fluoroscopic control. Clinicians usually use a low-compliance balloon such as Rigiflex dilator to perform endoscope-guided PD for the treatment of esophageal achalasia. It has the advantage of determining mucosal injury during the dilation process, so that a repeat endoscopy is not needed to assess the mucosal tearing. Previous studies have shown that endoscope-guided PD is an efficient and safe nonsurgical therapy with results that compare well with other treatment modalities. Although the results may be promising, long-term follow-up is required in the near future. PMID:20101764

  7. How to Prevent Leaving 'Needle Cast' or 'Cement Tail' in Vertebroplasty and Kyphoplasty

    Yang, Hui Lin; Sun, Zhi Yong; Zhang, Hong Tao; Zhu, Xiao Yu; Chen, Kang Wu; Qian, Zhong Lai [Dept. of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, Jiangs (China)


    Nowadays, percutaneous vertebroplasty, or its evolution kyphoplasty, is a valid therapeutic option for the management of severe back pain, caused by vertebral compression fractures (1). They are minimally invasive, radiologically guided interventional procedures, which involve the injection of polymethylmethacrylate (PMMA) into the fractured vertebral body. The injection process was monitored continuously, under a fluoroscopic control in the lateral plane (2). Ideally, the injection should be completed in 5 to 6 minutes and before the PMMA becomes too viscous to allow reinsertion of the stylus. This is not always possible, but is preferred to avoid the risk of leaving a 'needle castor a 'cement tail', within the soft tissues, as the needle is removed with the adherent cement (Fig. 1). In the event that the reinsertion cannot be achieved, great care should be taken to dislodge the adherent PMMA cement before extracting the needle from the vertebral body (3).

  8. CT fluoroscopy-assisted cervical transforaminal steroid injection: tips, traps, and use of contrast material.

    Hoang, Jenny K; Apostol, Marc A; Kranz, Peter G; Kilani, Ramsey K; Taylor, Jeffrey N; Gray, Linda; Lascola, Christopher D


    CT fluoroscopy-assisted cervical transforaminal steroid injection is an effective therapeutic option for cervical radiculopathy, yet it is approached with trepidation by some interventionalists. CT fluoroscopy is superior to conventional fluoroscopy for delineating complex anatomic relations in the neck but must be combined with careful technique to avoid rare but serious complications. We describe the anatomy of the neural foramen, our technique of CT fluoroscopy-assisted cervical transforaminal steroid injection, and the CT appearance of appropriate and inappropriate needle positions. Understanding anatomy will help to avoid complications and optimize the therapeutic potential of cervical transforaminal steroid injection. Use of contrast material for CT fluoroscopic guidance facilitates appropriate needle positioning and reduces the risk of complications.

  9. Improving outcomes: understanding the psychosocial aspects of the orthopaedic trauma patient.

    Levin, Paul E; MacKenzie, Ellen J; Bosse, Michael J; Greenhouse, Pamela K


    The care of orthopaedic trauma patients with multiple injuries has dramatically improved in the past 25 years. The understanding of the physiology of trauma has evolved, new surgical approaches have been developed, and technologic advances have created better implants. New methods of treating fractures include fluoroscopic and computer-assisted imaging. Surgical interventions have changed from extensive and prolonged dissections to more limited and effective percutaneous and minimally invasive techniques. The lives of patients are being saved, and radiographic outcomes are improving; however, medical and surgical advances that achieve better radiographic and anatomic outcomes do not always improve functional outcomes. Understanding and optimizing the management of the psychosocial factors that affect trauma patients can improve outcomes.

  10. Dual mobility total hip replacement in a high risk population

    Luthra, Jatinder Singh; Al Riyami, Amur; Allami, Mohamad Kasim


    Objective: The purpose of the study was to evaluate results of dual mobility total replacement in a high risk population who take hip into hyperflexed position while sitting and praying on the floor. Method: The study included 65 (35 primary total replacement and 30 complex total hip replacement) cases of total hip replacement using avantage privilege dual mobility cup system from biomet. A cemented acetabular component and on femoral side a bimetric stem, either cemented or uncemented used depending on the canal type. Ten cases were examined fluoroscopically in follow up. Result: There was dislocation in one patient undergoing complex hip replacement. Fluoroscopy study showed no impingement between the neck of prosthesis and acetabular shell at extremes of all movements. Conclusion: The prevalence of dislocation is low in our high risk population and we consider it preferred concept for patients undergoing complex total hip replacement. PMID:27924742

  11. Dual mobility total hip replacement in a high risk population

    Luthra Jatinder Singh


    Full Text Available Objective: The purpose of the study was to evaluate results of dual mobility total replacement in a high risk population who take hip into hyperflexed position while sitting and praying on the floor. Method: The study included 65 (35 primary total replacement and 30 complex total hip replacement cases of total hip replacement using avantage privilege dual mobility cup system from biomet. A cemented acetabular component and on femoral side a bimetric stem, either cemented or uncemented used depending on the canal type. Ten cases were examined fluoroscopically in follow up. Result: There was dislocation in one patient undergoing complex hip replacement. Fluoroscopy study showed no impingement between the neck of prosthesis and acetabular shell at extremes of all movements. Conclusion: The prevalence of dislocation is low in our high risk population and we consider it preferred concept for patients undergoing complex total hip replacement.

  12. A feasibility study into the use of three-dimensional printer modelling in acetabular fracture surgery.

    Yu, A W; Duncan, J M; Daurka, J S; Lewis, A; Cobb, J


    There are a number of challenges associated with the operative treatment of acetabular fractures. The approach used is often extensive, while operative time and perioperative blood loss can also be significant. With the proliferation of 3D printer technology, we present a fast and economical way to aid the operative planning of complex fractures. We used augmented stereoscopic 3D CT reconstructions to allow for an appreciation of the normal 3D anatomy of the pelvis on the fractured side and to use the models for subsequent intraoperative contouring of pelvic reconstruction plates. This leads to a reduction in the associated soft tissue trauma, reduced intraoperative time and blood loss, minimal handling of the plate, and reduced fluoroscopic screening times. We feel that the use of this technology to customize implants, plates, and the operative procedure to a patient's unique anatomy can only lead to improved outcomes.

  13. X-ray tomographic intervention guidance: Towards real-time 4D imaging

    Bartling, Sönke


    Implementation of real-time, continuous, and three-dimensional imaging (4D intervention guidance) would be a quantum leap for minimally-invasive medicine. It allows guidance during interventions by assessing the spatial position of instruments continuously in respect to their surroundings. Recent research showed that it is feasible using X-ray and novel tomographic reconstruction approaches. Radiation dose stays within reasonable limits. This article provides abstractions and background information together with an outlook on these prospects. There are explanations of how situational awareness during interventions is generated today and how they will be in future. The differences between fluoroscopically and CT-guided interventions are eluted to within the context of these developments. The exploration of uncharted terrain between these current methods is worth pursuing. Necessary image quality of 4D intervention guidance varies relevantly from that of standard computed tomography. Means to analyze the risk-b...

  14. Transforaminal Blood Patch for the Treatment of Chronic Headache from Intracranial Hypotension: A Case Report and Review

    Kirk Bowden


    Full Text Available This case report describes the successful treatment of chronic headache from intracranial hypotension with bilateral transforaminal (TF lumbar epidural blood patches (EBPs. The patient is a 65-year-old male with chronic postural headaches. He had not had a headache-free day in more than 13 years. Conservative treatment and several interlaminar epidural blood patches were previously unsuccessful. A transforaminal EBP was performed under fluoroscopic guidance. Resolution of the headache occurred within 5 minutes of the procedure. After three months without a headache the patient had a return of the postural headache. A second transforaminal EBP was performed again with almost immediate resolution. The patient remains headache-free almost six months from the time of first TF blood patch. This is the first published report of the use of transforaminal epidural blood patches for the successful treatment of a headache lasting longer than 3 months.

  15. Rectovaginal fistulography: a technique for the identification of recurrent elusive fistulas.

    Shobeiri, S Abbas; Quiroz, Lieschen; Nihira, Mikio


    The purpose of this study is to review our experience with a technique for diagnosing small rectovaginal fistulas that occasionally permit passage of air or mucus. During an in-office visit suspicious areas of the vagina were probed with a cone-tip catheter and injected with a contrast dye to visualize the suspected fistula tract communicating to the rectum under fluoroscopic guidance. The fistulous tracts were further isolated using a flexi-tip glide wire. Five out of nine patients were found to have fistulas not diagnosed by other means. Three patients had recurrent rectovaginal fistula after a vaginal delivery, one patient was identified with a high rectovaginal fistula due to diverticular disease, and one patient had a rectovaginal fistula due to prior hemorrhoidectomy. One patient had a negative test, and the fistula that was diagnosed intraoperatively was due to underlying Crohn's disease. Direct fistulography is a useful technique to visualize otherwise elusive symptomatic rectovaginal fistula tracts.

  16. Fluoroscopy-based navigation system in spine surgery

    Merloz, Philippe; Vouaillat, Hervé; Vasile, Christian; Tonetti, Jérôme; Eid, Ahmad; Plaweski, Stéphane


    The variability in width, height, and spatial orientation of a spinal pedicle makes pedicle screw insertion a delicate operation. The aim of the current paper is to describe a computer-assisted surgical navigation system based on fluoroscopic X-ray image calibration and three-dimensional optical localizers in order to reduce radiation exposure while increasing accuracy and reliability of the surgical procedure for pedicle screw insertion. Instrumentation using transpedicular screw fixation was performed: in a first group, a conventional surgical procedure was carried out with 26 patients (138 screws); in a second group, a navigated surgical procedure (virtual fluoroscopy) was performed with 26 patients (140 screws). Evaluation of screw placement in every case was done by using plain X-rays and post-operative computer tomography scan. A 5 per cent cortex penetration (7 of 140 pedicle screws) occurred for the computer-assisted group. A 13 per cent penetration (18 of 138 pedicle screws) occurred for the non comp...

  17. C1-2 arthrography

    Chevrot, A. [Service de Radiologie B, Hopital Cochin, 75 - Paris (France); Cermakova, E. [Service de Radiologie B, Hopital Cochin, 75 - Paris (France); Vallee, C. [Service de Radiologie B, Hopital Cochin, 75 - Paris (France); Chancelier, M.D. [Service de Radiologie B, Hopital Cochin, 75 - Paris (France); Chemla, N. [Service de Radiologie B, Hopital Cochin, 75 - Paris (France); Rousselin, B. [Service de Radiologie B, Hopital Cochin, 75 - Paris (France); Langer-Cherbit, A. [Service de Radiologie B, Hopital Cochin, 75 - Paris (France)


    One hundred patients with the following conditions were studied: cervical pain or neuralgia without radiographic changes, osteoarthritis, rheumatoid arthritis, ankylosing spondylarthritis and diverse conditions. The technique consists of lateral puncture of the posterior aspect of the C1-2 joint with a 20-gauge needle under fluoroscopic control, arthrography using 1 ml contrast medium, and a 1-ml long-acting steroid injection subsequently. The articular cavity has an anterior and a posterior recess. Sometimes the posterior recess is large. In 18% of cases the contralateral joint also opacifies. C1-2 arthrography appears to be an efficient and safe technique for the treatment of upper cervical pain due to C1-2 articular disorders. (orig.)

  18. Lagophthalmos after v2 maxillary nerve block.

    Shah, Amit A; Nedeljkovic, Srdjan S


    We report a previously undescribed complication associated with percutaneous maxillary nerve blockade. After the procedure, the patient reported an inability to close her ipsilateral eye (lagophthalmos). The patient had received 5 mL of 0.5% lidocaine for skin anesthesia. After needle placement was confirmed fluoroscopically, a combination of 80 mg methylprednisolone (2 mL) and 0.25% bupivacaine (3 mL) was administered. Symptoms resolved within 40 minutes. The likely cause was local anesthetic effect on the zygomatic branches of the facial nerve. When subcutaneous local anesthetic is given for maxillary block, smaller volumes should be considered. Doctors and patients should be aware of this complication, which may require treatment with artificial tears or patching of the eye to prevent corneal injury.

  19. Multidetector spiral CT arthrography of the shoulder. Clinical applications and limits, with MR arthrography and arthroscopic correlations.

    Lecouvet, Frédéric E; Simoni, Paolo; Koutaïssoff, Sophie; Vande Berg, Bruno C; Malghem, Jacques; Dubuc, Jean-Emile


    Although MR imaging and MR arthrography are the first choice modalities for shoulder imaging, CT arthrography (CTA) may be used successfully to address many clinical questions. The advent of submillimeter multiple detector CT technology and subsequent excellent three-plane resolution has considerably increased the quality of CTA examinations and has propelled this technique to the forefront in a growing number of indications. The combined use of iodinated contrast material for fluoroscopic confirmation of the articular position of the needle before injection of gadolinium chelates for MR arthrography offers the unique opportunity to compare CTA and MRA findings in carefully selected cases. This paper illustrates capabilities and limits of CTA for the study of rotator cuff tears, shoulder instability, cartilage lesions, anatomical variants and abnormalities of the glenoid labrum, with correlations to MR arthrography and surgical findings.

  20. Percutaneous gastroenterostomy

    Wittich, G.R.; Van Sonnenberg, E.; Casola, G.; Jantsch, H.; Walter, R.; Lechner, G.


    Percutaneous gastrostomies or gastroenterostomies serve for temporary or permanent enteric feeding in patients with obstruction or functional derangement of the esophagus or hypopharynx. In addition, this radiological procedure may be indicated for small bowel decompression. The authors present their experience in 71 patients. Insufflation of air through a nasogastric tube or catheter is the preferred method for gastric distension. The inferior margin of the left lobe of the liver and the transverse colon are localized sonographically and fluoroscopically prior to puncture. Either Seldinger or Trocartechniques have proven effective in establishing access to the stomach. The feeding tube is advanced into the proximal jejunum to reduce the likelyhood of gastroesophageal reflux and possible aspiration. Complications were encountered in four patients and included catheter dislocation in three and respiratory distress in one patient.

  1. Real-time navigation in transoral robotic nasopharyngectomy utilizing on table fluoroscopy and image overlay software: a cadaveric feasibility study.

    Tsang, Raymond K; Sorger, Jonathan M; Azizian, Mahdi; Holsinger, Christopher F


    Inability to integrate surgical navigation systems into current surgical robot is one of the reasons for the lack of development of robotic endoscopic skull base surgery. We describe an experiment to adapt current technologies for real-time navigation during transoral robotic nasopharyngectomy. A cone-beam CT was performed with a robotic C-arm after the injecting contrast into common carotid artery. 3D reconstruction of the skull images with the internal carotid artery (ICA) highlighted red was projected on the console. Robotic nasopharyngectomy was then performed. Fluoroscopy was performed with the C-arm. Fluoroscopic image was then overlaid on the reconstructed skull image. The relationship of the robotic instruments with the bony landmarks and ICA could then been viewed in real-time, acting as a surgical navigation system. Navigation during robotic skull base surgery is feasible with available technologies and can increase the safety of robotic skull base surgery.

  2. Outpatient experience with oesophageal endoscopic dilation.

    Jani, P G; Mburugu, P G


    Between March 1990 and August 1997, outpatient endoscopic balloon dilation was performed for oesophageal strictures which developed secondary to malignancies, peptic strictures, post surgical narrowing, achalasia cardia, corrosive ingestion and other causes. A total of 169 dilations were performed in the 92 cases with an average of 1.8 dilation/case (Range 1 to 8). Dilation was possible in all 92 cases without the need for fluoroscopic monitoring. Twenty three (13.6%) of the dilations were performed using pneumatic balloon while in 146(86.4%) cases wire guided metal olives were used. There were nine minor complications which were treated with medication on an outpatient basis and four major complications which required inpatient care. Three of these had perforation of the oesophagus and one died. One other patient developed aspiration pneumonia and subsequently died.

  3. [Percutaneous interventions in an open MR system: technical background and clinical indications].

    Fischbach, F; Fischbach, K; Ricke, J


    The latest and therefore more efficient open magnetic resonance (MR) scanners with a field strength of 1 T allow freehand fluoroscopic interventions with excellent image quality. Specifically designed interactive software simplifies examination planning and performance. Guidance in two imaging planes allows fast and accurate device positioning and interventional procedures during free breathing. The diagnostic and therapeutic spectrum includes a wide variety of interstitial percutaneous interventions. The most important are periradicular therapy (PRT), intra-abdominal drainage and nephrostoma placement, biopsies, especially in the breasts and liver and focal ablation therapy of malignant hepatic or renal lesions. As the approach is fast and robotic devices are not needed the method is increasingly being carried out in the clinical routine. A drawback of MR-guided interventions is the limitation in verbal communication during image acquisition. Furthermore, the portfolio of MR compatible instruments needs to be extended.

  4. NASA: Biomedical applications team


    The status of projects involving the adaptation of NASA technologies for medical purposes is reviewed. Devices for the measurement of joint deformation of arthritic hands, the development of an artificial pancreas, provision of an auditory signal to avert epileptic seizures, are described along with the control of medication levels, a compressed air tank to supply power for field dentistry, and an electroencephalogram monitor. The use of the Lixiscope as a portable fluoroscope, thermal laminates for hand and foot warmers for patients with Raynaud's syndrome, and the use of absorptive coatings for instruments for controlling medication levels are described. The applicability of occupation health and safety practices to industry, computerized patient scheduling, impregnation of the common facial tissue with an agent for killing respiratory viruses, commercial applications of anthropometric data, and multispectral image analysis of the skin as a diagnostic tool are reviewed.

  5. Computer Evaluation Of Real-Time X-Ray And Acoustic Images

    Jacoby, M. H.; Loe, R. S.; Dondes, P. A.


    The weakest link in the inspection process is the subjective interpretation of data by inspectors. To overcome this troublesome fact computer based analysis systems have been developed. In the field of nondestructive evaluation (NDE) there is a large class of inspections that can benefit from computer analysis. X-ray images (both film and fluoroscopic) and acoustic images lend themselves to automatic analysis as do the one-dimensional signals associated with ultrasonic, eddy current and acoustic emission testing. Computer analysis can enhance and evaluate subtle details. Flaws can be located and measured, and accept-ance decisions made by computer in a consistent and objective manner. This paper describes the interactive, computer-based analysis of real-time x-ray images and acoustic images of graphite/epoxy adhesively bonded structures.

  6. Role of delayed gastric emptying in the pathogenesis of cysteamine-induced duodenal ulcer in the rat

    Poulsen, Steen Seier


    Cysteamine is a potent duodenal ulcerogen in rats. It has been demonstrated to inhibit gastric empyting, whose role in ulcer formation is unknown. In the present study the effect of cysteamine on gastric motility and emptying rate in rats was studied by direct fluoroscopic observation. The delayed....... After 4 h this pool of undiluted gastric secretions gradually is emptied into the duodenum, where the mucosal resistance is reduced by inhibition of the secretory activity of Brunner's glands, and ulceration rapidly develops. The time relationship is supported by histopathologic findings...... and measurements of gastric acid secretions after cysteamine. Vagotomy augmented the inhibitory effect of cysteamine on gastric motility. The relaxation was even more pronounced, and contrast medium was not discharged from the stomach within 24 h. In these rats cysteamine induced ulcerations in the stomach....

  7. Direct aneurysm sac catheterization and embolization of an enlarging internal iliac aneurysm using cone-beam CT

    Merchant, Monish; Shah, Rohan; Resnick, Scott


    Since cone-beam computed tomography (CT) has been adapted for use with a C-arm system it has brought volumetric CT capabilities in the interventional suite. Although cone-beam CT image resolution is far inferior to that generated by traditional CT scanners, the system offers the ability to place an access needle into position under tomographic guidance and use the access to immediately begin a fluoroscopic procedure without moving the patient. We describe a case of a “jailed” enlarging internal iliac artery aneurysm secondary to abdominal aortic aneurysm repair, in which direct percutaneous puncture of the internal iliac artery aneurysm sac was performed under cone-beam CT guidance. PMID:25858522

  8. Efficacy of an Intra-Operative Imaging Software System for Anatomic Anterior Cruciate Ligament Reconstruction Surgery

    Xudong Zhang


    Full Text Available An imaging software system was studied for improving the performance of anatomic anterior cruciate ligament (ACL reconstruction which requires identifying ACL insertion sites for bone tunnel placement. This software predicts and displays the insertion sites based on the literature data and patient-specific bony landmarks. Twenty orthopaedic surgeons performed simulated arthroscopic ACL surgeries on 20 knee specimens, first without and then with the visual guidance by fluoroscopic imaging, and their tunnel entry positions were recorded. The native ACL insertion morphologies of individual specimens were quantified in relation to CT-based bone models and then used to evaluate the software-generated insertion locations. Results suggested that the system was effective in leading surgeons to predetermined locations while the application of averaged insertion morphological information in individual surgeries can be susceptible to inaccuracy and uncertainty. Implications on challenges associated with developing engineering solutions to aid in re-creating or recognizing anatomy in surgical care delivery are discussed.

  9. Modified Radiology-Guided Percutaneous Gastrostomy (MRPG) for Patients with Complete Obstruction of the Upper Digestive Tract and Who are without Endoscopic or Nasogastric Access

    Chan, Siu Cheung; Liu, Kar Wai; Liao, Chun Ta; Lee, Tsung Shih; Ng, Shu Hang [Chang Gung Memorial Hospital, Linkou Medical Center and Keelung Hospital, Taoyuan (China); Chu, Winnie Chiu Wing [The Chinese University of Hong Kong, Hong Kong (China)


    We wanted to report on our experience with modified radiology-guided percutaneous gastrostomy (MRPG) without endoscopic or nasogastric access for treating patients with complete obstruction of the upper digestive tract. Fourteen oncology patients (13 had hypopharyngeal cancer and 1 had upper esophageal cancer) with complete obstruction of the upper digestive tract were recruited. Conventional percutaneous endoscopic gastrostomy (PEG) and radiologic (fluoroscopy-guided) percutaneous gastrostomy (RPG) were not feasible in all the patients. An MRPG technique (with a combination of ultrasound, an air enema and fluoroscopic guidance) was performed in these patients. We achieved successfully percutaneous gastrostomy using the modified technique in all patients without any major or minor complications after the procedure. A modified radiology-guided percutaneous gastrostomy technique can be safely performed in patients who failed to receive conventional PEG or RPG due to the absence of nasogastric access in the completely obstructed upper digestive tract

  10. Necrotizing fasciitis caused by a primary appendicocutaneous fistula.

    Takeda, Makoto; Higashi, Yukihiro; Shoji, Tuyoshi; Hiraide, Takanori; Maruo, Hirotoshi


    We report a case of necrotizing fasciitis in the loin of a 76-year old man with several coexisting or past health issues, including diabetes mellitus, hypertension, alcohol-related liver cirrhosis, gastrectomy for gastric cancer, subarachnoid hemorrhage, normal pressure hydrocephalus, and cerebral infarction. Incision of the necrotizing fasciitis was successful, but it revealed an appendicocutaneous fistula; thus, we performed appendectomy and fistulectomy. We think that the necrotizing fasciitis was caused by appendicitis perforation involving the retroperitoneum, inducing the formation of an appendicocutaneous fistula. Necrotizing fasciitis and appendicocutaneous fistulae are rare complications of appendicitis. Moreover, to our knowledge, this is the first report of fluoroscopic examination demonstrating that a primary appendicocutaneous fistula had caused necrotizing fasciitis. Our search of the literature found 12 cases of necrotizing fasciitis caused by preoperative appendicitis. We discuss the characteristics and findings of these cases.

  11. Construction of source positioning system in RALS with using I.I.-DR image

    Minamoto, Takahiro; Oda, Masahiko; Nakae, Yasuo [Hyogo Coll. of Medicine, Nishinomiya (Japan). Hospital; Kamikonya, Norihiko; Nakao, Norio [Hyogo Coll. of Medicine, Nishinomiya (Japan)


    In the Remote After Loading System (RALS), the source position is reconstructed as a 3 dimensional position by X-ray catheter points on bi-plane X-ray films. There are several reconstruction methods. However, the geometrical accuracy of the source coordinate position is important to evaluate dose distribution in any case. Many institutions adopted a C-arm X-ray fluoroscopic system with a rotational mechanism due to the simplicity of handling. However, the image intensifier (I.I.)-digital radiography (DR) image by the C-arm system has image distortion that results from mechanical accuracy and fluorescence plane of I.I., and films are used to confirm the source position in RALS. Therefore, the RALS positioning system that corrected I.I. DR image distortion was reconstructed. RALS positioning system kept reconstruction accuracy of the source coordinate position within 1 mm and this system also realized simplification of work and shortening in treatment time. (author)

  12. Refinement of a thrombectomy technique to treat acute ischemic stroke: Technical note on microcatheter advance during retrieving self expandable stent

    Youn, Sung Won; Kim, Ho Kyun [Catholic Univ. of Daegu School of Medicine, Daegu (Korea, Republic of)


    Temporary stenting and thrombectomy by use of the Solitaire stent (ev3, Irvine, CA, USA) has shown prompt and successful recanalization of the acutely occluded major cerebral artery. However, even if rarely reported, inadvertent stent detachment may occur as an innate drawback and full deployment of the stent was considered to increase the risk. In our patients, the Solitaire stent did not fully unfold to prevent inadvertent detachment. Before retrieval of the stent, the tip of the microcatheter was advanced forward carefully under fluoroscopic observation until it met the presumed thrombus segment and a subtle sense of resistance was felt in the fingers guiding the stent. After retrieval, complete recanalization was achieved, and the thrombus was trapped between the tip of the microcatheter and the stent strut. We present 2 cases of successful thrombi captures by advancing a microcatheter during Solitaire stent retrieval, and we suggest that advancing the microcatheter can be a useful refinement to the thrombectomy technique for acute ischemic stroke.

  13. [Minimally invasive cement augmentation of osteoporotic vertebral compression fractures with the new radiofrequency kyphoplasty].

    Mattyasovszky, S G; Kurth, A A; Drees, P; Gemidji, J; Thomczyk, S; Kafchitsas, K


    Minimally invasive cement augmentation of painful osteoporotic vertebral compression fractures in elderly patients. Painful osteoporotic vertebral compression fractures in elderly patients (> 65 years of age) after conservative therapy failure. Painful aggressive primary tumors of the spine or osteolytic metastases to the spine with high risk of vertebral fracture in the palliative care setting. General contraindications for surgical interventions. Local soft-tissue infection. Osteomyelitis, discitis or systemic infection. Coagulopathy refractory to treatment or bleeding diathesis. Asymptomatic vertebral compression fractures. Burst of the posterior vertebral column with high degree of spinal canal stenosis. Primary or metastatic spinal tumors with epidural growth. Prone position on a radiolucent operating table. Fluoroscopic localization of the fractured vertebra using two conventional C-arm devices (anteroposterior and lateral views). Fluoroscopic localization of the fractured vertebra using two conventional C-arm devices (anteroposterior and lateral views). An introducer is inserted through a small skin incision into the pedicle under fluoroscopic guidance. To create a site- and size-specific three-dimensional cavity in the center of the fractured vertebra, the navigational VertecoR™ MidLine Osteotome was inserted through the correctly sited introducer and guided fluoroscopically. As the MidLine Osteotome allows angulation of the tip up to 90° by rotating the handle, a cavity over the midline of the vertebral body can mainly be created through one pedicle. The radiofrequency activated cohesive ultrahigh viscosity PMMA cement (ER(2) bone cement) is injected stepwise on demand by remote control under continuous pressure from the hydraulic assembly into the vertebral body. Bed rest for 6 h postoperatively in supine position. Early mobilization without a corset on the day of surgery. Specific back and abdominal exercises that strengthen the back and abdominal

  14. Design Of A Multiformat Camera For Medical Fluoroscopy

    Edmonds, Ernest W.; Hynes, David M.; Baranoski, Dennis; Rowlands, John; Krametz, Karl R.


    For a number of years multi-format or multi-image cameras have been used in radiology departments to record images for ultrasound, nuclear medicine and computerized tomography. The authors have described in previous papers the development of a total low dose fluoroscopy system, using a Siemens Videomed H 1023 line 25 MHz television system, a V.A.S. video disc recorder for pulsed fluoroscopy, and a modified Matrix Videoimager to record the spot film images. This approach has provided images of high quality with dose and cost reductions of the order of 90% for the total examination. The particular problems involved with the modification of a multi-image camera for fluoroscopic or radiographic procedures, can be minimised by appropriate choice of monitor phosphor and correct control of the exposure sequence.

  15. An interesting journey of an ingested needle: a case report and review of the literature on extra-abdominal migration of ingested Foreign bodies

    Gezen Fazli C


    Full Text Available Abstract Swallowed foreign bodies encounter a major problem especially in children, but fortunately they mostly do not cause any related complication and are easily passed with the stool. In this paper, an interesting journey of a needle is presented. A 20-year old female admitted to our emergency service after she had swallowed a sewing machine needle, which is initially observed in the stomach in the plain abdominal radiography. During the follow-up period, the needle traveled through bowels, and surprisingly was observed in the left lung on 10th day of the follow-up. It was removed with a thoracotomy and pneumotomy under the fluoroscopic guidance. The postoperative period was uneventful and the patient was discharged from the hospital on the day 5. We also review the literature on interesting extra-abdominal migrations of swallowing foreign bodies.

  16. Pediatric interventional radiology and dose-reduction techniques.

    Johnson, Craig; Martin-Carreras, Teresa; Rabinowitz, Deborah


    The pediatric interventional radiology community has worked diligently in recent years through education and the use of technology to incorporate numerous dose-reduction strategies. This article seeks to describe different strategies where we can significantly lower the dose to the pediatric patient undergoing a diagnostic or therapeutic image-guided procedure and, subsequently, lower the dose several fold to the staff and ourselves in the process. These strategies start with patient selection, dose awareness and monitoring, shielding, fluoroscopic techniques, and collimation. Advanced features such as cone-beam technology, dose-reduction image processing algorithms, overlay road mapping, and volumetric cross-sectional hybrid imaging are also discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Multidetector spiral CT arthrography of the shoulder

    Lecouvet, Frederic E. [Departments of Radiology and Orthopaedic Surgery, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Hippocrate Avenue 10/2942, 1200 Brussels (Belgium)], E-mail:; Simoni, Paolo; Koutaissoff, Sophie; Vande Berg, Bruno C.; Malghem, Jacques; Dubuc, Jean-Emile [Departments of Radiology and Orthopaedic Surgery, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Hippocrate Avenue 10/2942, 1200 Brussels (Belgium)


    Although MR imaging and MR arthrography are the first choice modalities for shoulder imaging, CT arthrography (CTA) may be used successfully to address many clinical questions. The advent of submillimeter multiple detector CT technology and subsequent excellent three-plane resolution has considerably increased the quality of CTA examinations and has propelled this technique to the forefront in a growing number of indications. The combined use of iodinated contrast material for fluoroscopic confirmation of the articular position of the needle before injection of gadolinium chelates for MR arthrography offers the unique opportunity to compare CTA and MRA findings in carefully selected cases. This paper illustrates capabilities and limits of CTA for the study of rotator cuff tears, shoulder instability, cartilage lesions, anatomical variants and abnormalities of the glenoid labrum, with correlations to MR arthrography and surgical findings.

  18. [Perioperative high-caloric alimentation with the central venous catheter. Prospective study in 404 patients].

    Stock, W; Weber, M; Doht, R


    Peri-operative high-calorie nutrition was administered, through a total of 500 catheters introduced into the superior vena cava via the subclavian vein, to 404 patients admitted to hospital for gastro-intestinal cancer resection or other major abdominal operations, some of them taking a complicated course. Most of the catheters remained in situ for 6-20 days; the longest period was 44 days. Catheter insertion was successful in 97.8%. Faulty position of the catheter occurred in 4.4%; in 2.8% it was rectified under fluoroscopic control. In 92.2% there were no complications ascribable to the catheter. A pneumothorax resulted in 1.4% of patients, central thrombosis in 0.4%. Catheter-related sepsis was noted in 6.2%.

  19. Effect of Intraoperative Three-Dimensional Imaging During the Reduction and Fixation of Displaced Calcaneal Fractures on Articular Congruence and Implant Fixation

    Eckardt, Henrik; Lind, Marianne


    articular displacement was 0 mm in 69% of the Sanders type 2 fractures and 57% of the Sanders type 3 fractures. Operation duration averaged 118 minutes, and there were no reoperations due to misplaced screws or plates. The average absorbed radiation dose per patient was 288 mGy·cm. CONCLUSION......BACKGROUND: Operative treatment of displaced calcaneal fractures should restore joint congruence, but conventional fluoroscopy is unable to fully visualize the subtalar joint. We questioned whether intraoperative 3-dimensional (3D) imaging would aid in the reduction of calcaneal fractures......, resulting in improved articular congruence and implant positioning. METHOD: Sixty-two displaced calcaneal fractures were operated on using standard fluoroscopic views. When the surgeon had achieved a satisfactory reduction, an intraoperative 3D scan was conducted, malreductions or implant imperfections were...

  20. Transorbital Approach for Endovascular Occlusion of Carotid-Cavernous Fistulas: Technical Note and Review of the Literature

    Chen, Ching-Jen; Caruso, James P; Ding, Dale; Schmitt, Paul J; Buell, Thomas J; Raper, Daniel M; Evans, Avery; Newman, Steven A; Jensen, Mary E


    Carotid-cavernous fistulas (CCFs) pose an anatomically and physiologically challenging problem for clinicians. The most common method of treatment for these lesions is transvenous endovascular embolization via the inferior petrosal sinus or the facial vein. When transvenous access is not possible, an alternate approach must be devised. We describe a case example with bilateral Barrow Type B CCFs, which were inaccessible using the traditional transvenous approach. Hence, a direct transorbital approach, performed under fluoroscopic guidance, was employed to successfully obliterate the CCF. At five months follow-up, the patient was recovering without complications. This case delineates the technical aspects of transorbital CCF embolization and demonstrates that this approach is a viable alternative to conventional transvenous methods for appropriately selected CCF cases. We supplement our case example and technical note with a literature review of this approach. PMID:28191380

  1. [The Mexican Institute of Social Security Institute (IMSS) in Numbers. Functional inventory of imaging medical equipment, 2003].


    Medical technology is a fundamental instrument for the provision of health services in the Mexican Institute of Social Security (IMSS) and as a support for diagnostic and therapeutic interventions. The inventory of relevant medical equipment describes the needs for upgrading the technological infrastructure, organize its distribution and plan its renovation in order to guarantee the quality of health services. In this report we describe the type of equipment used in radiology and other imaging services, its geographical distribution, median age in operation and its productivity. The inventory reported 2091 pieces of equipment, ultrasonography and radiology were the most common types (31%) followed by fluoroscopic equipment (20%). Follow-up in the inventory should help in planning the acquisition and maintenance of sophisticated technology used for medical purposes.

  2. [The history and development of computer assisted orthopaedic surgery].

    Jenny, J-Y


    Computer assisted orthopaedic surgery (CAOS) was developed to improve the accuracy of surgical procedures. It has improved dramatically over the last years, being transformed from an experimental, laboratory procedure into a routine procedure theoretically available to every orthopaedic surgeon. The first field of application of computer assistance was neurosurgery. After the application of computer guided spinal surgery, the navigation of total hip and knee joints became available. Currently, several applications for computer assisted surgery are available. At the beginning of navigation, a preoperative CT-scan or several fluoroscopic images were necessary. The imageless systems allow the surgeon to digitize patient anatomy at the beginning of surgery without any preoperative imaging. The future of CAOS remains unknown, but there is no doubt that its importance will grow in the next 10 years, and that this technology will probably modify the conventional practice of orthopaedic surgery.

  3. Navigated percutaneous screw fixation of a periprosthetic acetabular fracture.

    Gras, Florian; Marintschev, Ivan; Klos, Kajetan; Fujak, Albert; Mückley, Thomas; Hofmann, Gunther O


    Periprosthetic fractures are severe complications of total hip arthroplasty with increasing incidence. Most fractures are localized around the femoral component of prosthesis, whereas periacetabular fractures are rare and their management is difficult. In most cases, an operative procedure with revision and exchange of the acetabular cup is necessary. The approaches are demanding and an increased risk of complications is reported. We present the case of a female patient with a cementless total hip arthroplasty due to severe arthritis, suffering of an infratectal transverse periprosthetic fracture. After an initial conservative treatment attempt, we performed a minimally invasive screw fixation using navigated 2-dimensional fluoroscopic guidance. In this report, the literature for treatment recommendations is reviewed and the chosen navigation technique discussed. Copyright © 2010. Published by Elsevier Inc.

  4. Assessment of a percutaneous iliosacral screw insertion simulator

    Tonetti, J; Girard, P; Dubois, M; Merloz, P; Troccaz, Jocelyne; 10.1016/j.otsr.2009.07.005


    BACKGROUND: Navigational simulator use for specialized training purposes is rather uncommon in orthopaedic and trauma surgery. However, it reveals providing a valuable tool to train orthopaedic surgeons and help them to plan complex surgical procedures. PURPOSE: This work's objective was to assess educational efficiency of a path simulator under fluoroscopic guidance applied to sacroiliac joint percutaneous screw fixation. MATERIALS AND METHODS: We evaluated 23 surgeons' accuracy inserting a guide-wire in a human cadaver experiment, following a pre-established procedure. These medical trainees were defined in three prospective respects: novice or skilled; with or without theoretical knowledge; with or without surgical procedure familiarity. Analysed criteria for each tested surgeon included the number of intraoperative X-rays taken in order to achieve the surgical procedure as well as an iatrogenic index reflecting the surgeon's ability to detect any hazardous trajectory at the time of performing said procedu...

  5. The patient perspective on the Riata defibrillator lead advisory

    Larsen, Jacob M; Riahi, Sam; Johansen, Jens B


    BACKGROUND: The St Jude Medical Riata lead advisory was issued owing to insulation failures. The impact of this advisory on patients' well-being is unknown. OBJECTIVES: The objectives of this study were to describe the acute impact of the Riata advisory on patients' well-being and psychological...... functioning and to examine changes over time. METHODS: Patients with active Riata leads completed standardized and validated patient-reported outcomes (PROs) in connection with a nationwide fluoroscopic screening with 12-month follow-up. They were matched (1:1) on age, sex, and implant indication...... of a high advisory impact on general well-being as assessed with a purpose-designed question (odds ratio 2.24; P = .04). Device-related concerns decreased over time (d = -0.17; P = .002), but no changes were seen for other PROs. CONCLUSION: The Riata advisory is associated with a persistent small reduction...

  6. Concealed malfunction of the temporary pacemaker

    Mohammad Alasti


    Full Text Available The 12-lead ECG shows sequential atrial and ventricular pacing (Figure 1A. A tracing, obtained simultaneously during pacemaker interrogation, disclosed pacemaker functioning as VDD mode (Figure 1B. The careful examination of this pacemaker tracing showed that there is a pacing stimulus before each P wave (compatible with DDD mode. This paradox can only be explained by displacement of the temporary pacing lead to right atrium and right atrial stimulation by temporary pacemaker. In this setting, each temporary pacemaker-induced atrial depolarization is tracked by the right atrial lead of the permanent pacemaker as intrinsic P wave. Fluoroscopic study confirmed this explanation (Figure 2. The displaced temporary pacing lead was seen near the lateral right atrial wall. Temporary pacemaker lead had been inserted before replacement of permanent pacemaker.

  7. The line-noise-reduction for low dose x-ray fluoroscopy with the flat panel detector

    Nakamura, Tadashi; Ikeda, Shigeyuki; Suzuki, Katsumi; Takenouchi, Shinobu


    A scintillator type Flat Panel Detector (FPD)1 has a good noise performance especially in Fluoroscopic images because of high DQE. Almost same dose as I.I. and CCD system is accepted in clinical use. According to the clinical study, the dose in fluoroscopy will be decreased if we can reduce the line noise coming from gate line of the Thin Film Transistor (TFT). The purpose of this study is to detect and reduce this line noise from the fluoroscopic images making it possible to perform a lower dose of fluoroscopy imaging. We detected the line noise by acquiring a dark image (without exposure) and then comparing the average of the line data along to the gate line to the neighborhood lines. We have applied this method to the dark area taken by the collimator of the Lucite phantom image and detected it. The detected line will be compensated by interpolation with neighborhood lines. The FPD of our system2 has a big detecting area (40cm x 30cm) and a zoom mode is selected in fluoroscopy because the doctor is watching an edge of the guide-wire and a contrast medium. The collimated area of the detector is displayed in a monitor after the zooming process and we can take a collimated dark area for detecting the line noise. As we applied this method to the dark image (1024pixels x 1024lines) including 54 lines with noise, we can improve 10% of SD. Visible line noise of chest phantom image was reduced with this method. It will help to lower the fluoroscopy dose.

  8. Outcome of percutaneous rupture of lumbar synovial cysts: a case series of 101 patients.

    Martha, Julia F; Swaim, Bryan; Wang, David A; Kim, David H; Hill, James; Bode, Rita; Schwartz, Carolyn E


    Lumbar facet joint synovial cysts are benign degenerative abnormalities of the lumbar spine. Previous reports have supported operative and nonoperative management. Facet joint steroid injection with cyst rupture is occasionally performed, but there has been no systematic evaluation of this treatment option. To profile the role of facet joint steroid injections with cyst rupture in the treatment of lumbar facet joint synovial cysts. Retrospective chart review and long-term follow-up of patients treated for lumbar facet joint synovial cysts. One hundred one patients treated for lumbar facet joint synovial cysts with fluoroscopically guided corticosteroid facet joint injection and attempted cyst rupture. Oswestry Disability Index and numeric rating scale score for back and leg pain. A retrospective review and a subsequent interview were conducted to collect pretreatment and posttreatment pain and disability scores along with details of subsequent treatment interventions. Group differences in pain and disability scores were assessed using paired t test. Multiple clinical factors were analyzed in terms of risk for surgical intervention using logistic regression modeling and Cox proportional hazards modeling. Successful cyst rupture was confirmed fluoroscopically in 81% of cases. Fifty-five patients (54%) required subsequent surgery over a period averaging 8.4 months because of inadequate symptom relief. All patients reported significant improvement in back pain, leg pain, and disability at 3.2 years postinjection, regardless of their subsequent treatment course (ptreatment for lumbar facet joint synovial cysts. Lumbar facet joint steroid injection with attempted cyst rupture is correlated with avoiding subsequent surgery in half of treated patients. Successful cyst rupture does not appear to have added benefit, and it was associated with worse disability 3 years postinjection. Long-term outcomes are similar, regardless of subsequent surgery.

  9. [Thrombolysis in mechanical prosthetic valve thrombosis. Its management with streptokinase].

    Solorio, S; Sánchez, H; Madrid, R; Badui, E; Valdespino, A; Murillo, H; Rangel, A; Enciso, R


    We present the first experience in Mexico in 10 patients, 9 female and 1 male with an average age of 42.5 years. All patients had clinical, echocardiographic and fluoroscopic criteria of dysfunctioning mechanical valvular prosthesis due to thrombosis (9 Sorin type and 1 Starr-Edwards). None of the patients had contraindications for thrombolytic therapy. All cases were treated with intravenous streptokinase: 250,000 U in 30 minutes followed by an infusion of 100,000 U per hour, always under clinical, echocardiographic and fluoroscopic control every 2 and 24 hours respectively until the normalization of the clinical and hemodynamic parameters with a top limit of 72 hour. The average duration of the thrombolysis was 54 +/- 6.1 hours with an average total doses of 5' 200,000 U of streptokinase. In 90% of the cases there was an increase in the valvular area: mitral (n = 7), from 1.02 +/- 0.21 to 1.75 +/- 0.36 cm2 (p < 0.001), while the mean transvalvular gradient decreased from 10.42 +/- 3.77 to 3.42 +/- 0.975 mmHg (p < 0.001); the systolic pulmonary artery pressure also decreased from 53.7 +/- 15.29 to 35 +/- 2 mmHg (p < 0.001). In the tricuspid prosthesis (n = 2) the average valvular area was increased from 0.8 +/- 0.44 to 1.55 +/- 0.77 cm2, decreasing proportionally the mean transvalvular gradient from 12.5 +/- 2 to 4.5 +/- 3.5 mmHg with no changes in the systolic pressure of the pulmonary artery. In the Starr-Edwards prosthesis in aortic position (n = 1), no hemodynamic changes were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. In vivo kinematics and articular surface congruency of total ankle arthroplasty during gait.

    Yamaguchi, Satoshi; Tanaka, Yasuhito; Banks, Scott; Kosugi, Shinichi; Sasho, Takahisa; Takahashi, Kazuhisa; Takakura, Yoshinori


    Relatively high rates of loosening and implant failure have been reported after total ankle arthroplasty. Abnormal kinematics and incongruency of the articular surface may cause increased contact pressure and rotational torque applied to the implant, leading to loosening and implant failure. We measured in vivo kinematics of two-component total ankle arthroplasty (TNK ankle), and assessed congruency of the articular surface during the stance phase of gait. Eighteen ankles of 15 patients with a mean age of 75±6 years (mean±standard deviation) and follow-up of 44±38 months were enrolled. Lateral fluoroscopic images were taken during the stance phase of gait. 3D-2D model-image registration was performed using the fluoroscopic image and the implant models, and three-dimensional kinematics of the implant and incongruency of the articular surface were determined. The mean ranges of motion were 11.1±4.6°, 0.8±0.4°, and 2.6±1.5° for dorsi-/plantarflexion, inversion/eversion, and internal/external rotation, respectively. At least one type of incongruency of the articular surface occurred in eight of 18 ankles, including anterior hinging in one ankle, medial or lateral lift off in four ankles, and excessive axial rotation in five ankles. Among the four ankles in which lift off occurred during gait, only one ankle showed lift off in the static weightbearing radiograph. Our observations will provide useful data against which kinematics of other implant designs, such as three-component total ankle arthroplasty, can be compared. Our results also showed that evaluation of lift off in the standard weightbearing radiograph may not predict its occurrence during gait.

  11. Computer-assisted auto-frame navigation system for distal locking of tibial intramedullary nails: a preliminary report on clinical application

    WANG Jun-qiang; GAO Yi-fei; WANG Tian-miao; ZHAO Chun-peng; WANG Man-yi; SU Yong-gong; HU Lei; SUN Lei; ZHANG Li-dan; LIU Wen-yong; ZHANG Hui


    Objective: To evaluate the clinical feasibility and effect of the computer-assisted auto-frame navigation system for distal locking of tibial intrameduilary nails.Methods: The hardware components of the system included a PC computer with a monitor, auto mechanical stereotactical locating cubic frame, foot holder and localization operative apparatus. Special navigation software can be used for registration of X-ray fluoroscopic images and real-time controlling navigation of tools.Twenty-one cases of close tibial and fibular fractures were treated with closed intramedullary nailing, 6 of which involved in middle third, 12 in middle and lower third, 3 in lower third. C-arm alignment and registration time,fluoroscopic time and drilling time involved in the locking procedure were recorded. The size of unreamed or reamed tibial nails ranged from 8/300-11/330.Results: All distal holes except 1 were locked successfully. In 9 of 41 locked holes (21.95%), the drill bit touched the canal of locking hole without damage of the nail and clinical consequences. The fluoroscopy time per pair of screws was 2.23 s ± 0.31 s.Conclusions: The computer-assisted auto-frame navigation system for distal locking is well designed, easy to operate and do not need additional instruments during the procedure. The developed system enables the physician to precisely navigate surgical instruments throughout the anatomy using just a few computer-calibrated radiographic images. The total time of x-ray exposure per procedure can be significantly reduced.

  12. Computerized fluoroscopy with zero-dose image updates for minimally invasive femoral diaphyseal fracture reduction

    Zheng, Guoyan; Dong, Xiao


    In this paper, a computerized fluoroscopy with zero-dose image updates for femoral diaphyseal fracture reduction is proposed. It is achieved with a two-step procedure. Starting from a few (normally 2) calibrated fluoroscopic image, the first step, data preparation, automatically estimates the size and the pose of the diaphyseal fragments through three-dimensional morphable object fitting using a parametric cylinder model. The projection boundary of each estimated cylinder, a quadrilateral, is then fed to a region information based active contour model to extract the fragment contours from the input fluoroscopic images. After that, each point on the contour is interpolated relative to the four vertices of the corresponding quadrilateral, which resulted in four interpolation coefficients per point. The second step, image updates, repositions the fragment projection on each acquired image during bony manipulation using a computerized method. It starts with interpolation of the new position of each point on the fragment contour using the interpolation coefficients calculated in the first step and the new position of the corresponding quadrilateral. The position of the quadrilateral is updated in real time according to the positional changes of the associated bone fragments, as determined by the navigation system during fracture reduction. The newly calculated image coordinates of the fragment contour are then fed to a OpenGL® based texture warping pipeline to achieve a real-time image updates. The presented method provides a realistic augmented reality for the surgeon. Its application may result in great reduction of the X-ray radiation to the patient and to the surgical team.

  13. Percutaneous Augmented Peripheral Osteoplasty in Long Bones of Oncologic Patients for Pain Reduction and Prevention of Impeding Pathologic Fracture: The Rebar Concept

    Kelekis, A., E-mail:; Filippiadis, D., E-mail: [University General Hospital “ATTIKON”, 2nd Radiology Department (Greece); Anselmetti, G., E-mail: [GVM Care and Research Maria Pia Hospital (Italy); Brountzos, E., E-mail: [University General Hospital “ATTIKON”, 2nd Radiology Department (Greece); Mavrogenis, A., E-mail:; Papagelopoulos, P., E-mail: [University General Hospital “ATTIKON”, A Orthopedic Clinic (Greece); Kelekis, N., E-mail: [University General Hospital “ATTIKON”, 2nd Radiology Department (Greece); Martin, J.-B., E-mail: [Centre Imaginerie Rive Droite & Gauche (Switzerland)


    PurposeTo evaluate clinical efficacy/safety of augmented peripheral osteoplasty in oncologic patients with long-term follow-up.Materials and MethodsPercutaneous augmented peripheral osteoplasty was performed in 12 patients suffering from symptomatic lesions of long bones. Under extensive local sterility measures, anesthesiology care, and fluoroscopic guidance, direct access to lesion was obtained and coaxially a metallic mesh consisting of 25–50 medical grade stainless steel micro-needles (22 G, 2–6 cm length) was inserted. PMMA for vertebroplasty was finally injected under fluoroscopic control. CT assessed implant position 24-h post-treatment.ResultsClinical evaluation included immediate and delayed follow-up studies of patient’s general condition, NVS pain score, and neurological status. Imaging assessed implant’s long-term stability. Mean follow-up was 16.17 ± 10.93 months (range 2–36 months). Comparing patients’ scores prior (8.33 ± 1.67 NVS units) and post (1.42 ± 1.62 NVS units) augmented peripheral osteoplasty, there was a mean decrease of 6.92 ± 1.51 NVS units. Overall mobility improved in 12/12 patients. No complication was observed.ConclusionPercutaneous augmented peripheral osteoplasty (rebar concept) for symptomatic malignant lesions in long bones seems to be a possible new technique for bone stabilization. This combination seems to provide necessary stability against shearing forces applied in long bones during weight bearing.

  14. Online tracking of interventional devices for endovascular aortic repair.

    Volpi, Daniele; Sarhan, Mhd H; Ghotbi, Reza; Navab, Nassir; Mateus, Diana; Demirci, Stefanie


    The continuous integration of innovative imaging modalities into conventional vascular surgery rooms has led to an urgent need for computer assistance solutions that support the smooth integration of imaging within the surgical workflow. In particular, endovascular interventions performed under 2D fluoroscopic or angiographic imaging only, require reliable and fast navigation support for complex treatment procedures such as endovascular aortic repair. Despite the vast variety of image-based guide wire and catheter tracking methods, an adoption of these for detecting and tracking the stent graft delivery device is not possible due to its special geometry and intensity appearance. In this paper, we present, for the first time, the automatic detection and tracking of the stent graft delivery device in 2D fluoroscopic sequences on the fly. The proposed approach is based on the robust principal component analysis and extends the conventional batch processing towards an online tracking system that is able to detect and track medical devices on the fly. The proposed method has been tested on interventional sequences of four different clinical cases. In the lack of publicly available ground truth data, we have further initiated a crowd sourcing strategy that has resulted in 200 annotations by unexperienced users, 120 of which were used to establish a ground truth dataset for quantitatively evaluating our algorithm. In addition, we have performed a user study amongst our clinical partners for qualitative evaluation of the results. Although we calculated an average error in the range of nine pixels, the fact that our tracking method functions on the fly and is able to detect stent grafts in all unfolding stages without fine-tuning of parameters has convinced our clinical partners and they all agreed on the very high clinical relevance of our method.

  15. CT fluoroscopy guided percutaneous gastrostomy or jejunostomy without (CT-PG/PJ) or with simultaneous endoscopy (CT-PEG/PEJ) in otherwise untreatable patients.

    Spelsberg, Fritz W; Hoffmann, Ralf-Thorsten; Lang, Reinhold A; Winter, Hauke; Weidenhagen, Rolf; Reiser, Maximilian; Jauch, Karl-Walter; Trumm, Christoph


    Percutaneous endoscopic gastrostomy (PEG) or percutaneous endoscopic jejunostomy (PEJ) are substantial for patients with swallowing disorders to maintain enteral nutrition or to decompress palliatively intractable small bowel obstruction. Endoscopic placement can be impossible due to previous (gastric) operation, obesity, hepato-splenomegaly, peritoneal carcinosis, inadequate transillumination, or obstructed passage. Computed tomography (CT)-fluoroscopic guidance with or without endoscopy can enable placement of CT-PG/CT-PJ or CT-PEG/CT-PEJ if endoscopically guided placement fails. In this retrospective study, we will evaluate the feasibility and safety of this method. A total of 101 consecutive patients were referred to our department for feeding support (n = 87) or decompression (n = 14). Reasons were: ENT tumor (n = 51), esophageal cancer (n = 19), mediastinal mass (n = 2), neurological disorder (n = 15). Decompression tubes were placed because of cancer (n = 13) or Crohn's disease (n = 1). The following approaches were chosen: CT fluoroscopy and simultaneous gastroscopy (n = 61), inflation of the stomach via nasogastric tube (n = 29), and direct puncture under CT-fluoroscopic guidance (n = 11). CT fluoroscopy-guided gastrostomy was feasible in 89 of 101 patients. No procedure-related mortality was observed. One tube was misplaced into the colon in a patient with a history of gastrectomy. No complication was seen after removal. Minor complications: dislodgement (n = 17), peristomal leakage (n = 7), wound infection (n = 1), superficial skin infection (n = 6), tube obstruction (n = 2). CT fluoroscopy-guided PG/PJ or PEG/PEJ is feasible and safe and provides adequate feeding support or decompression. It offers the benefits of minimally invasive therapy even in patients with contraindications to established endoscopic methods, combining the advantages of both techniques. Long-term complications-mainly tube-related problems-are easily treated.

  16. Comparison of fluoro and cine coronary angiography: balancing acceptable outcomes with a reduction in radiation dose.

    Olcay, Ayhan; Guler, Ekrem; Karaca, Ibrahim Oguz; Omaygenc, Mehmet Onur; Kizilirmak, Filiz; Olgun, Erkam; Yenipinar, Esra; Cakmak, Huseyin Altug; Duman, Dursun


    Use of last fluoro hold (LFH) mode in fluoroscopy, which enables the last live image to be saved and displayed, could reduce radiation during percutaneous coronary intervention when compared with cine mode. No previous study compared coronary angiography radiation doses and image quality between LFH and conventional cine mode techniques. We compared cumulative dose-area product (DAP), cumulative air kerma, fluoroscopy time, contrast use, interobserver variability of visual assessment between LFH angiography, and conventional cine angiography techniques. Forty-six patients were prospectively enrolled into the LFH group and 82 patients into the cine angiography group according to operator decision. Mean cumulative DAP was higher in the cine group vs the LFH group (50058.98 ± 53542.71 mGy•cm² vs 11349.2 ± 8796.46 mGy•cm²; Pcine group vs the LFH group (3.87 ± 5.08 minutes vs 1.66 ± 1.51 minutes; Pcine group vs the LFH group (112.07 ± 43.79 cc vs 88.15 ± 23.84 cc; Pcine and LFH angiography groups (0.66680 ± 0.19309 vs 0.54193 ± 0.31046; P=.20). Radiation doses, contrast use, and fluoroscopy times are lower in fluoroscopic LFH angiography vs cine angiography. Interclass variability of visual stenosis estimation between three operators was not different between cine and LFH groups. Fluoroscopic LFH images conventionally have inferior diagnostic quality when compared with cine coronary angiography, but with new angiographic systems with improved LFH image quality, these images may be adequate for diagnostic coronary angiography.

  17. First report of image integration of cine-angiography with 3D electro-anatomical mapping of the right ventricle in postoperative tetralogy of Fallot.

    Russo, Mario Salvatore; Righi, Daniela; Di Mambro, Corrado; Ruoppolo, Valentina; Silvetti, Massimo Stefano; Drago, Fabrizio


    Ventricular tachycardia and, more rarely, sudden cardiac death are potential complications affecting the long-term outcome after Tetralogy of Fallot (ToF) repair. Intraventricular septal scar, fibro-fatty substitution around infundibular resection and patchy myocardial fibrosis may provide anatomical substrates of abnormal depolarization and repolarization causing reentrant ventricular arrhythmias. Recently, three-dimensional electro-anatomical mapping (3D EAM) has allowed to investigate the electro-anatomical status of the right ventricle. Radiation exposure during cardiac electrophysiological procedures is still a major concern. We report the first case of 3D mapping of the right ventricle in a postoperative ToF patient performed with a new module of the CARTO® 3 System-the CARTOUnivu™ Module-that combines, simultaneously, fluoroscopic images or cine-angiographic sequences with 3D cardiac mapping to allow real-time visualization of the electrocatheter during the 3D EAM reconstruction. The same volume, previously evaluated with cardiac MRI, was mapped. A perfect match of the diastolic edges of the RV obtained either by cine-loop acquisition during contrast fluoroscopy and by the 3D EAM, was observed. The fluoroscopy time for 3D EAM was 10 s. In conclusion, CARTOUnivu™ Module can integrate, in real time, fluoroscopic images/cine-angiography in virtual biplane view and the 3D EAM allowing a contextual visualization of position and movement of all electrocatheters. This can further increase the accuracy of the 3D EAM in very complex-operated congenital heart diseases, even decreasing radiation exposure.

  18. Percutaneous Retrieval of Foreign Bodies Around Vital Vessels Aided with Vascular Intervention: A Technical Note

    Yang, Xiu-Jun, E-mail: [Shanghai Eighth People’s Hospital, Department of Radiology (China); Xing, Guang-Fu, E-mail: [Shanghai Eighth People’s Hospital, Department of General Surgery (China)


    ObjectiveTo describe a new interventional technique to remove foreign bodies (FBs) embedded in soft tissues around vital vessels.MethodsUnder fluoroscopic guidance and using local anesthesia, percutaneous removal of FBs was performed using forceps in nine patients. All patients suffered from a metallic soft tissue FB located in close proximity to important vessels and one also had a small traumatic pseudoaneurysm adjacent to the FB. Prior to removal of the FB, the position of the nearest vessel was identified using a guide wire or catheter placed into the vessel. Balloon catheter was also simultaneously used to temporarily stop the blood flow of the nearest artery during the FB removal in three of the nine patients.ResultsAll of the nine FBs with 0–2 mm interval to the nearest vessel were successfully removed in the nine patients without any serious complications. The removed FBs measured 3–12 mm in length and 1–3 mm in width. The total fluoroscopic time of retrieval of each FB was 5–9 min (mean, 6.4 min). The volume of intraoperative bleeding ranged from 5 to 12 ml (mean, 7.5 ml). The length of hospital stay for each patient ranged from 4 to 8 days (mean, 5.5 days).ConclusionVascular intervention-aided percutaneous FB removal is minimally invasive and an effective method for removal of FBs around vital vessels.

  19. Comparative study of W-shaped angular plate and reconstruction plate in treating posterior wall fractures of the acetabulum.

    Qi Zhang

    Full Text Available OBJECTIVE: This study aims to assess the medium-term results of the reconstruction of posterior wall fractures using a W-shaped acetabular angular plate (WAAP compared to those fixed using a reconstruction plate. METHODS: Between July 2006 and March 2009, we performed a retrospective study, which collected data for any patient treated for a posterior acetabular wall fracture. At the time of treatment, patients were either treated using a WAAP or a pelvic reconstruction plate. The intraoperative fluoroscopic images for both groups were compared. The quality of reduction and radiological grading were assessed according to the criteria developed by Matta. The clinical assessment was based on a modified Merle d'Aubigne and Postel scoring. RESULTS: 53 patients met the inclusion criteria and were followed up for an average of 38 months. 25 patients were treated with a WAAP (study group, and 28 patients were treated with a pelvic reconstruction plate (control group. The intraoperative fluoroscopic images of the study group confirmed extra-articular screw placement in all cases. In the control group, intra-articular screw placement was observed intraoperatively in 5 patients (17.86%, and the definitive location of the periarticular hardware could not be determined in 4 patients (14.29% during the operation. The differences between the two groups were statistically significant (p = 0.002. In contrast, the quality of fracture reduction, clinical outcomes, and radiological grading in the study group were not significantly different from those of the control group (p>0.05. The radiographic grade was strongly associated with the clinical outcomes in both the study and control groups (p<0.05. CONCLUSION: Reconstruction of posterior wall fractures of the acetabulum using a WAAP can help avoid screw penetration of the hip joint, provide a stable fixation of the posterior wall, and ensure good clinical outcomes.

  20. Comparative study on treatment of midshaft tibial fracture with expandable and interlocking intramedullary nails

    BI Qing; ZHU Dan-jie; QIU Bin-song; HONG Jian-fei; ZHANG Shui-jun; XIA Bing


    Objective:To evaluate the clinical results of treatment of midshaft tibial fracture with expandable intramedullary nails compared with interlocking intramedullary nails.Methods: From June 2003 to August 2005, 46 patients (27 males and 19 females, aged 20-74 years, mean = 38. 4 years) with midshaft tibial fracture were treated surgically in our department. The causes of fractures were traffic injury in 21 patients, fall injury in 6, tumbling injury in 11 and crushing injury in 8. According to AO/ ASIF classification, Type A fracture was found in 16 patients, Type B in 11, Type C, in 5, and Type C2 in 2. Open fractures were found in 12 patients, according to Gustilo classification, Type Ⅰ in 9 patients and Type Ⅱ in 3 patients. Based on the patients'consent, 24 patients were treated with expandable intramedullary nails (Group A) and 22 with interlocking intramedullary nails (Group B). The operation time, blood loss during operation, X-ray fluoroscopic times, hospitalization time, weight bearing time after operation, healing time of fracture andcomplications of all the patients were recorded. The clinical effects of all the cases were evaluated according to the criteria of Johner-Wruhs.Results: All the patients were followed up for 12-34 months (mean =16.2 months). The time of operation, the blood loss, X-ray fluoroscopic times, hospitalization time and healing time of fracture of Group A significantly decreased (P < 0.05) compared with those of Group B, but the time for weight bearing after operation, the Johner-Wruhs degree of clinical effects and complications had no significant difference between Group A and Group B (P>0.05).Conclusions: Expandable intramedullary nail can shorten operation time, decrease blood loss and reduce invasion, which is a safe and effective treatment method for tibial midshaft fracture.

  1. Creation of an iOS and Android Mobile Application for Inferior Vena Cava (IVC) Filters: A Powerful Tool to Optimize Care of Patients with IVC Filters.

    Deso, Steven E; Idakoji, Ibrahim A; Muelly, Michael C; Kuo, William T


    Owing to a myriad of inferior vena cava (IVC) filter types and their potential complications, rapid and correct identification may be challenging when encountered on routine imaging. The authors aimed to develop an interactive mobile application that allows recognition of all IVC filters and related complications, to optimize the care of patients with indwelling IVC filters. The FDA Premarket Notification Database was queried from 1980 to 2014 to identify all IVC filter types in the United States. An electronic search was then performed on MEDLINE and the FDA MAUDE database to identify all reported complications associated with each device. High-resolution photos were taken of each filter type and corresponding computed tomographic and fluoroscopic images were obtained from an institutional review board-approved IVC filter registry. A wireframe and storyboard were created, and software was developed using HTML5/CSS compliant code. The software was deployed using PhoneGap (Adobe, San Jose, CA), and the prototype was tested and refined. Twenty-three IVC filter types were identified for inclusion. Safety data from FDA MAUDE and 72 relevant peer-reviewed studies were acquired, and complication rates for each filter type were highlighted in the application. Digital photos, fluoroscopic images, and CT DICOM files were seamlessly incorporated. All data were succinctly organized electronically, and the software was successfully deployed into Android (Google, Mountain View, CA) and iOS (Apple, Cupertino, CA) platforms. A powerful electronic mobile application was successfully created to allow rapid identification of all IVC filter types and related complications. This application may be used to optimize the care of patients with IVC filters.

  2. Fate of bone marrow mesenchymal stem cells following the allogeneic transplantation of cartilaginous aggregates into osteochondral defects of rabbits.

    Yoshioka, Tomokazu; Mishima, Hajime; Kaul, Zeenia; Ohyabu, Yoshimi; Sakai, Shinsuke; Ochiai, Naoyuki; Kaul, Sunil C; Wadhwa, Renu; Uemura, Toshimasa


    The purpose of this study was to track mesenchymal stem cells (MSCs) labelled with internalizing quantum dots (i-QDs) in the reparative tissues, following the allogeneic transplantation of three-dimensional (3D) cartilaginous aggregates into the osteochondral defects of rabbits. QDs were conjugated with a unique internalizing antibody against a heat shock protein-70 (hsp70) family stress chaperone, mortalin, which is upregulated and expressed on the surface of dividing cells. The i-QDs were added to the culture medium for 24 h. Scaffold-free cartilaginous aggregates formed from i-QD-labelled MSCs (i-MSCs), using a 3D culture system with chondrogenic supplements for 1 week, were transplanted into osteochondral defects of rabbits. At 4, 8 and 26 weeks after the transplantation, the reparative tissues were evaluated macroscopically, histologically and fluoroscopically. At as early as 4 weeks, the defects were covered with a white tissue resembling articular cartilage. In histological appearance, the reparative tissues resembled hyaline cartilage on safranin-O staining throughout the 26 weeks. In the deeper portion, subchondral bone and bone marrow were well remodelled. On fluoroscopic evaluation, QDs were tracked mainly in bone marrow stromata, with some signals detected in cartilage and the subchondral bone layer. We showed that the labelling of rabbit MSCs with anti-mortalin antibody-conjugated i-QDs is a tolerable procedure and provides a stable fluorescence signal during the cartilage repair process for up to 26 weeks after transplantation. The results suggest that i-MSCs did not inhibit, and indeed contributed to, the regeneration of osteochondral defects.

  3. In vivo 3-dimensional analysis of scapular and glenohumeral kinematics: comparison of symptomatic or asymptomatic shoulders with rotator cuff tears and healthy shoulders.

    Kijima, Takehiro; Matsuki, Keisuke; Ochiai, Nobuyasu; Yamaguchi, Takeshi; Sasaki, Yu; Hashimoto, Eiko; Sasaki, Yasuhito; Yamazaki, Hironori; Kenmoku, Tomonori; Yamaguchi, Satoshi; Masuda, Yoshitada; Umekita, Hideo; Banks, Scott A; Takahashi, Kazuhisa


    Alteration in shoulder kinematics has been suggested as one cause of symptoms in shoulders with rotator cuff tears (RCTs). However, only a few studies comparing symptomatic and asymptomatic RCTs using kinematic analysis have been performed. The purpose of this study was to compare 3-dimensional (3D) scapular and glenohumeral kinematics during scapular-plane abduction among symptomatic RCTs, asymptomatic RCTs, and healthy shoulders. This study included 7 healthy shoulders in subjects with a mean age of 62 years, 5 symptomatic RCTs in subjects with a mean age of 70 years, and 7 asymptomatic RCTs in subjects with a mean age of 67 years. All shoulders with RCTs had medium-sized tears (1-3 cm in the coronal plane) that were confirmed with magnetic resonance imaging. Biplane fluoroscopic images during scapular-plane abduction were recorded, and computed tomography-derived 3D bone models were matched with the silhouettes of the bones on the fluoroscopic images using 3D/2-dimensional model-image registration techniques. Angular values of the scapula and glenohumeral kinematics were compared among the 3 groups. Posterior tilt of the scapula was significantly smaller in the symptomatic RCTs (3.1° ± 1.8°) than in healthy shoulders (10.4° ± 0.8°) (P = .049). The humerus of the symptomatic shoulders was less externally rotated relative to the scapula throughout the activity than the healthy shoulders and asymptomatic RCTs (P = .006 and P = .028 respectively). However, there were no kinematic differences between the asymptomatic RCTs and healthy shoulders. Kinematic changes in symptomatic RCTs might be associated with development of symptoms. Improvement of these kinematic changes may be a key to successful conservative treatment for symptomatic RCTs. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  4. Establishment of a protocol for determining gastrointestinal transit time in mice using barium and radiopaque markers

    Myagmarjaibuu, Bilomaa; Moon, Myeong Ju; Heo, Suk Hee; Jeong, Seo In; Jeong, Yong Yeon; Kang, Heoung Keun [Dept. of Radiology, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun (Korea, Republic of); Park, Jong Seong [Dept. of Physiology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Jun, Jae Yeoul [Dept. of Physiology, College of Medicine, Chosun University, Gwangju (Korea, Republic of)


    The purpose of this study was to establish a minimally invasive and reproducible protocol for estimating the gastrointestinal (GI) transit time in mice using barium and radiopaque markers. Twenty 5- to 6-week-old Balb/C female mice weighing 19-21 g were used. The animals were divided into three groups: two groups that received loperamide and a control group. The control group (n = 10) animals were administered physiological saline (1.5 mL/kg) orally. The loperamide group I (n = 10) and group II (n = 10) animals were administered 5 mg/kg and 10 mg/kg loperamide orally, respectively. Thirty minutes after receiving the saline or loperamide, the mice was administered 80 μL of barium solution and six iron balls (0.5 mm) via the mouth and the upper esophagus by gavage, respectively. Afterwards, the mice were continuously monitored with fluoroscopic imaging in order to evaluate the swallowing of the barium solution and markers. Serial fluoroscopic images were obtained at 5- or 10-min intervals until all markers had been excreted from the anal canal. For analysis, the GI transit times were subdivided into intestinal transit times (ITTs) and colon transit times (CTTs). The mean ITT was significantly longer in the loperamide groups than in the control group (p < 0.05). The mean ITT in loperamide group II (174.5 ± 32.3) was significantly longer than in loperamide group I (133.2 ± 24.2 minute) (p < 0.05). The mean CTT was significantly longer in loperamide group II than in the control group (p < 0.05). Also, no animal succumbed to death after the experimental procedure. The protocol for our study using radiopaque markers and barium is reproducible and minimally invasive in determining the GI transit time of the mouse model.

  5. Percutaneous vertebroplasty for osteoporotic vertebral compression fractures: experiences and prospective clinical outcome in 26 consecutive patients with 50 vertebral fractures; Perkutane Vertebroplastie der osteoporotischen Wirbelkoerperfraktur: Erfahrungen und prospektive Ergebnisse bei 26 Patienten mit 50 Frakturen

    Fessl, R.; Roemer, F.W.; Bohndorf, K. [Klinik fuer Diagnostische Radiologie und Neuroradiologie, Klinikum Augsburg (Germany)


    Purpose: prospective evaluation of vertebroplasty for osteoporotic compression fractures concerning pain reduction, demand of analgesics and quality of life. Material and Methods: in 26 consecutive patients, 50 vertebral fractures were treated by percutaneous vertebroplasty under fluoroscopic (n = 44) or combined fluoroscopic/CT guidance (n = 6). Prospective follow-up was performed after 6 (for 50 vertebral fractures) and 12 months (for 27 vertebral fractures). Visual analogue scale (VAS) and numeric rating scale (NRS) was applied for the assessment of pain. Subjective quality of life and analgesics demand was documented semi-quantitatively. Results: mean interval from the beginning of pain symptoms to therapy was 8.5 weeks. Vertebroplasty was technically successful in all evaluated patients. Pain severity decreased from 10 (defined at baseline as initial pain score) to 2.8 after 6 months and 2.7 after 12 months. Subjective quality of life was reported as very well, well or improved in 92% (n = 26 after 6 months) or 100% (n = 13 after 12 months). No need for additional analgesic therapy was observed in 69.3% (n = 26) after 6 months and 61.5% (n = 13) after 12 months. Eight newly developed vertebral fractures were observed during follow-up, with 5 fractures directly adjacent to previously treated vertebrae. Leakage of polymethyl methacrylate (PMMA) into the intervertebral space or spinal canal was observed in 22% and 20% respectively (n = 50 vertebrae). No neurologic deterioration or complications requiring surgery were observed. Conclusion: vertebroplasty is a successful therapeutic approach for the treatment of osteoporotic vertebral fractures. Persistent improvement of clinical symptoms was shown at follow-up after 6 and 12 months. (orig.)

  6. Physiological interpretations of radiographic findings on malformations of small veins: seriality of cisterns, communications to systemic veins and relationship to muscles

    Morita, Nobuo; Terada, Tomoaki; Sato, Morio; Sonomura, Tetsuo


    Objectives To re-evaluate the fluoroscopic findings of venous malformation by cine mode cisternography. Methods Using direct injection cine-cisternography, we studied 49 venous malformation lesions in the head and neck of 30 patients who were scheduled to undergo ethanol sclerotherapy. The diameter of definitively measurable 46 lesions was 21.7 ± 10.5 mm (mean ± SD, range: 6.0–48.0 mm). The injection was continued until the draining veins were clearly observed. Outflow communications between cisterns and systemic veins were classified into Type 1, no visible drainage; Type 2, draining into a normal venous system; and Type 3, with abnormally ectatic draining veins. The topological relationships of the lesions to surrounding structures were addressed using computed tomography, magnetic resonance imaging or ultrasonogram. Treatment results were evaluated. Results The direct injection cine-cisternography showed the typical ‘bunch of grapes’ pattern, and revealed serial cisternal, followed by the appearance of outflow/draining veins in all lesions. There were no Type 1, 47 Type 2 and two Type 2 outflow pattern. Satellite lesions emerged via the communicating veins in six lesions. Of the all 49 lesions, 48 were located in or on the muscle fascia. Sclerotherapy was safely completed in all Type 2 lesions with satisfactory results, but for the Type 3 lesions treatment was limited to be partial to avoid complications. Conclusions The present study suggested that communications from venous malformation to the systemic vein are fluoroscopically confirmable. These radiographic findings were thought explainable in relation to developmental nature or facilitating process of venous malformation. PMID:23223003

  7. Deep architecture neural network-based real-time image processing for image-guided radiotherapy.

    Mori, Shinichiro


    To develop real-time image processing for image-guided radiotherapy, we evaluated several neural network models for use with different imaging modalities, including X-ray fluoroscopic image denoising. Setup images of prostate cancer patients were acquired with two oblique X-ray fluoroscopic units. Two types of residual network were designed: a convolutional autoencoder (rCAE) and a convolutional neural network (rCNN). We changed the convolutional kernel size and number of convolutional layers for both networks, and the number of pooling and upsampling layers for rCAE. The ground-truth image was applied to the contrast-limited adaptive histogram equalization (CLAHE) method of image processing. Network models were trained to keep the quality of the output image close to that of the ground-truth image from the input image without image processing. For image denoising evaluation, noisy input images were used for the training. More than 6 convolutional layers with convolutional kernels >5×5 improved image quality. However, this did not allow real-time imaging. After applying a pair of pooling and upsampling layers to both networks, rCAEs with >3 convolutions each and rCNNs with >12 convolutions with a pair of pooling and upsampling layers achieved real-time processing at 30 frames per second (fps) with acceptable image quality. Use of our suggested network achieved real-time image processing for contrast enhancement and image denoising by the use of a conventional modern personal computer. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  8. The value of flat-detector computed tomography during catheterisation of congenital heart disease

    Gloeckler, Martin [University Hospital Erlangen, Department of Pediatric Cardiology, Erlangen (Germany); Friedrich-Alexander University Erlangen-Nuernberg, Department of Pediatric Cardiology, Erlangen (Germany); Koch, Andreas; Greim, Verena; Shabaiek, Amira; Dittrich, Sven [University Hospital Erlangen, Department of Pediatric Cardiology, Erlangen (Germany); Rueffer, Andre; Cesnjevar, Robert [University Hospital Erlangen, Department of Congenital Heart Surgery, Erlangen (Germany); Achenbach, Stephan [University Hospital Erlangen, Department of Cardiology, Erlangen (Germany)


    To analyse the diagnostic utility of flat-detector computed tomography imaging (FD-CT) in patients with congenital heart disease, including the value of image fusion to overlay three-dimensional (3D) reconstructions on fluoroscopic images during catheter-based interventions. We retrospectively analysed 62 consecutive paediatric patients in whom FD-CT was used during catheterisation of congenital heart disease. Expert operators rated the clinical value of FD-CT over conventional fluoroscopic imaging. Added radiation exposure and contrast medium volume were evaluated. During a 12-month period, FD-CT was performed in 62 out of 303 cardiac catheterisations. Median patient age was 3.5 years. In 32/62 cases, FD-CT was used for diagnostic purposes, in 30/62 cases it was used in the context of interventions. Diagnostic utility was never rated as ''misleading''. It was classified as ''not useful'' in six cases (9.7%), ''useful'' in 18 cases (29.0%), ''very useful'' in 37 cases (59.7%) and ''essential'' in one case (1.6%). The median added dose-area product was 111.0 {mu}Gym{sup 2}, the required additional quantity of contrast medium was 1.6 ml/kg. FD-CT provides useful diagnostic information in most of the patients investigated for congenital heart disease. The added radiation exposure and contrast medium volume are reasonable. (orig.)

  9. Ultrasound Guidance for Renal Tract Access and Dilation Reduces Radiation Exposure during Percutaneous Nephrolithotomy

    Thomas Chi


    Full Text Available Purposes. To present our series of 38 prone percutaneous nephrolithotomy procedures performed with renal access and tract dilation purely under ultrasound guidance and describe the benefits and challenges accompanying this approach. Methods. Thirty-eight consecutive patients presenting for percutaneous nephrolithotomy for renal stone removal were included in this prospective cohort study. Ultrasonographic imaging in the prone position was used to obtain percutaneous renal access and guide tract dilation. Fluoroscopic screening was used only for nephrostomy tube placement. Preoperative, intraoperative, and postoperative procedural and patient data were collected for analysis. Results. Mean age of patients was 52.7±17.2 years. Forty-five percent of patients were male with mean BMI of 26.1±7.3 and mean stone size of 27.2±17.6 millimeters. Renal puncture was performed successfully with ultrasonographic guidance in all cases with mean puncture time of 135.4±132.5 seconds. Mean dilation time was 11.5±3.8 min and mean stone fragmentation time was 37.5±29.0 min. Mean total operative time was 129.3±41.1. No patients experienced any significant immediate postoperative complication. All patients were rendered stone-free and no additional secondary procedures were required. Conclusions. Ultrasound guidance for renal access and tract dilation in prone percutaneous nephrolithotomy is a feasible and effective technique. It can be performed safely with significantly reduced fluoroscopic radiation exposure to the patient, surgeon, and intraoperative personnel.

  10. Intra-operative measurement of applied forces during anterior scoliosis correction.

    Fairhurst, H; Little, J P; Adam, C J


    Spinal instrumentation and fusion for the treatment of scoliosis is primarily a mechanical intervention to correct the deformity and halt further progression. While implant-related complications remain a concern, little is known about the magnitudes of the forces applied to the spine during surgery, which may affect post-surgical outcomes. In this study, the compressive forces applied to each spinal segment during anterior instrumentation were measured in a series of patients with Adolescent Idiopathic Scoliosis. A force transducer was designed and retrofit to a routinely used surgical tool, and compressive forces applied to each segment during surgery were measured for 15 scoliosis patients. Cobb angle correction achieved by each force was measured on intra-operative fluoroscope images. Relative changes in orientation of the screw within the vertebra were also measured to detect intra-operative screw plough. Intra-operative forces were measured for a total of 95 spinal segments. The mean applied compressive force was 540N (SD 230N, range 88N-1019N). There was a clear trend for higher forces to be applied at segments toward the apex of the scoliosis. Fluoroscopic evidence of screw plough was detected at 10 segments (10.5%). The magnitude of forces applied during anterior scoliosis correction vary over a broad range. These forces do reach magnitudes capable of causing intra-operative vertebral body screw plough. Surgeons should be aware there is a risk for tissue overload during correction, however the clinical implications of intra-operative screw plough remain unclear. The dataset presented here is valuable for providing realistic input parameters for in silico surgical simulations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Radiation dose measurement and risk estimation for paediatric patients undergoing micturating cystourethrography.

    Sulieman, A; Theodorou, K; Vlychou, M; Topaltzikis, T; Kanavou, D; Fezoulidis, I; Kappas, C


    Micturating cystourethrography (MCU) is considered to be the gold-standard method used to detect and grade vesicoureteric reflux (VUR) and show urethral and bladder abnormalities. It accounts for 30-50% of all fluoroscopic examinations in children. Therefore, it is crucial to define and optimize the radiation dose received by a child during MCU examination, taking into account that children have a higher risk of developing radiation-induced cancer than adults. This study aims to quantify and evaluate, by means of thermoluminescence dosimetry (TLD), the radiation dose to the newborn and paediatric populations undergoing MCU using fluoroscopic imaging. Evaluation of entrance surface dose (ESD), organ and surface dose to specific radiosensitive organs was carried out. Furthermore, the surface dose to the co-patient, i.e. individuals helping in the support, care and comfort of the children during the examination, was evaluated in order to estimate the level of risk. 52 patients with mean age of 0.36 years who had undergone MCU using digital fluoroscopy were studied. ESD, surface doses to thyroid, testes/ovaries and co-patients were measured with TLDs. MCU with digital equipment and fluoroscopy-captured image technique can reduce the radiation dose by approximately 50% while still obtaining the necessary diagnostic information. Radiographic exposures were made in cases of the presence of reflux or of the difficulty in evaluating a finding. The radiation surface doses to the thyroid and testes are relatively low, whereas the radiation dose to the co-patient is negligible. The risks associated with MCU for patients and co-patients are negligible. The results of this study provide baseline data to establish reference dose levels for MCU examination in very young patients.

  12. Endoscopic ultrasound-guided drainage of pelvic abscess: A case series of 8 patients

    Muhammed; Hadithi; Marco; J; Bruno


    AIM: To show the safety and effectiveness of endo-scopic ultrasound(EUS)-guided drainage of pelvic ab-scess that were inaccessible for percutaneous drainage. METHODS: Eight consecutive patients with pelvic abscess that were not amenable to drainage under computed tomography(CT) guidance were referred for EUS-guided drainage. The underlying cause of the abscesses included diverticulitis in 4, postsurgical surgi-cal complications in 2, iatrogenic after enema in 1, and Crohn’s disease in 1 patient. Abscesses were all drained under EUS guidance via a transrectal or transsigmoidal approach. RESULTS: EUS-guided placement of one or two 7 Fr pigtail stents was technically successful and uneventful in all 8 patients(100%). The abscess was perisigmoidal in 2 and was multilocular in 4 patients. All procedures were performed under conscious sedation and without fluoroscopic monitoring. Fluid samples were success-fully retrieved for microbiological studies in all cases and antibiotic policy was adjusted according to cultureresults in 5 patients. Follow-up CT showed complete re-covery and disappearance of abscess. The stents were retrieved by sigmoidoscopy in only two patients and had spontaneously migrated to outside in six patients. All drainage procedures resulted in a favourable clinical outcome. All patients became afebrile within 24 h after drainage and the mean duration of the postprocedure hospital stay was 8 d(range 4-14). Within a median follow up period of 38 mo(range 12-52) no recurrence was reported. CONCLUSION: We conclude that EUS-guided drain-age of pelvic abscesses without fluoroscopic monitoring is a minimally invasive, safe and effective approach that should be considered in selected patients.

  13. Limitations of anti-scatter grids when used with high resolution image detectors

    Singh, V.; Jain, A.; Bednarek, D. R.; Rudin, S.


    Anti-scatter grids are used in fluoroscopic systems to improve image quality by absorbing scattered radiation. A stationary Smit Rontgen X-ray grid (line density: 70 lines/cm, grid ratio: 13:1) was used with a flat panel detector (FPD) of pixel size 194 micron and a high-resolution CMOS detector, the Dexela 1207 with pixel size of 75 microns. To investigate the effectiveness of the grid, a simulated artery block was placed in a modified uniform frontal head phantom and imaged with both the FPD and the Dexela for an approximately 15 x 15 cm field of view (FOV). The contrast improved for both detectors with the grid. The contrast-to-noise ratio (CNR) does not increase as much in the case of the Dexela as it improves in the case of the FPD. Since the total noise in a single frame increases substantially for the Dexela compared to the FPD when the grid is used, the CNR is degraded. The increase in the quantum noise per frame would be similar for both detectors when the grid is used due to the attenuation of radiation, but the fixed pattern noise caused by the grid was substantially higher for the Dexela compared to the FPD and hence caused a severe reduction of CNR. Without further corrective methods this grid should not be used with high-resolution fluoroscopic detectors because the CNR does not improve significantly and the visibility of low contrast details may be reduced. Either an anti-scatter grid of different design or an additional image processing step when using a similar grid would be required to deal with the problem of scatter for high resolution detectors and the structured noise of the grid pattern.

  14. SU-D-304-01: Development of An Applicator for Treating Shallow and Moving Tumors with Respiratory-Gated Spot-Scanning Proton Therapy Using Real-Time Image Guidance

    Matsuura, T; Fujii, Y; Takao, S; Yamada, T; Matsuzaki, Y; Miyamoto, N; Shimizu, S; Shirato, H [Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Hokkaido (Japan); Takayanagi, T; Fujitaka, S [Hitachi, Ltd., Hitachi Research Laboratory, Hitachi, Ibaraki (Japan); Umegaki, K [Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido (Japan)


    Purpose: To develop a method for treating shallow and moving tumors (e.g., lung tumors) with respiratory-gated spot-scanning proton therapy using real-time image guidance (RTPT). Methods: An applicator was developed which can be installed by hand on the treatment nozzle. The mechanical design was considered such that the Bragg peaks are placed at the patient surface while a sufficient field of view (FOV) of fluoroscopic X-rays was maintained during the proton beam delivery. To reduce the treatment time maintaining the robustness of the dose distribution with respect to motion, a mini-ridge filter (MRF) was sandwiched between two energy absorbers. The measurements were performed to obtain a data for beam modeling and to verify the spot position-invariance of a pencil beam dose distribution. For three lung cancer patients, treatment plans were made with and without the MRF and the effects of the MRF were evaluated. Next, the effect of respiratory motion on the dose distribution was investigated. Results: To scan the proton beam over a 14 x 14 cm area while maintaining the φ16 cm of fluoroscopic FOV, the lower face of the applicator was set 22 cm upstream of the isocenter. With an additional range variance of 2.2 mm and peak-to-peak distance of 4 mm of the MRF, the pencil beam dose distribution was unchanged with the displacement of the spot position. The quality of the treatment plans was not worsened by the MRF. With the MRF, the number of energy layers was reduced to less than half and the treatment time by 26–37%. The simulation study showed that the interplay effect was successfully suppressed by respiratory-gating both with and without MRF. Conclusions: The spot-scanning proton beam was successfully delivered to shallow and moving tumors within a sufficiently short time by installing the developed applicator at the RTPT nozzle.

  15. Surgeon's and Patient's Radiation Exposure Through Vertebral Body Cement Augmentation Procedures: A Prospective Multicentric Study of 49 Cases.

    Lonjon, Nicolas; Le Corre, Marine; Le Roy, Julien; Greffier, Joël; Fuentes, Stéphane; Tonetti, Jérôme; Charles, Yann Philippe; Blondel, Benjamin; Kouyoumdjïan, Pascal


    Vertebral body cement augmentation as a treatment option for osteoporotic or traumatic fractures has become increasingly popular during the past decade. However, these surgical procedures require numerous fluoroscopic examinations, resulting in high radiation exposure for the patient and the surgical team. The aim of this study was to evaluate the level of radiation exposure of the spine surgeon and the patient during these percutaneous procedures. Forty-nine patients admitted for single- or 2-level vertebral compression fracture were prospectively included and treated with vertebral body cement augmentation. For each procedure, radiation dose was measured on the surgeon's whole body, lens, and extremities as well as patient irradiation. Each surgeon wore 2 thermoluminescent dosimeters to measure lens and extremities radiation exposure and 1 electronic personal dosimeter. Patient clinical and surgical data, effective dose to patient, and surgeon were analyzed. Mean operative time was 31.5 ± 11.7 minutes. The average fluoroscopic time was 61.0 ± 27.1 seconds. The average whole-body radiation dose per procedure was 1.4 ± 2.1 μSv. The average equivalent dose to lens and extremities were 44 μSv and 59 μSv, respectively. Values of radiation doses for surgeon and patient were lower than those reported in the previous literature. The recommended annual dose limit is set to 500 mSv for extremities and 150 mSv for lens. According to our results, the exposure dose to the eye exceeds the annual limit after 3500 procedures. However, there is increasing concern among surgeons about radiation exposure, and there is still a need for solutions as preventive measures. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Quantitative analysis of an enlarged area Solid State X-ray Image Intensifier (SSXII) detector based on Electron Multiplying Charge Coupled Device (EMCCD) technology.

    Swetadri, Vasan S N; Sharma, P; Singh, V; Jain, A; Ionita, Ciprian N; Titus, A H; Cartwright, A N; Bednarek, D R; Rudin, S


    Present day treatment for neurovascular pathological conditions involves the use of devices with very small features such as stents, coils, and balloons; hence, these interventional procedures demand high resolution x-ray imaging under fluoroscopic conditions to provide the capability to guide the deployment of these fine endovascular devices. To address this issue, a high resolution x-ray detector based on EMCCD technology is being developed. The EMCCD field-of-view is enlarged using a fiber-optic taper so that the detector features an effective pixel size of 37 µm giving it a Nyquist frequency of 13.5 lp/mm, which is significantly higher than that of the state of the art Flat Panel Detectors (FPD). Quantitative analysis of the detector, including gain calibration, instrumentation noise equivalent exposure (INEE) and modulation transfer function (MTF) determination, are presented in this work. The gain of the detector is a function of the detector temperature; with the detector cooled to 5° C, the highest relative gain that could be achieved was calculated to be 116 times. At this gain setting, the lowest INEE was measured to be 0.6 µR/frame. The MTF, measured using the edge method, was over 2% up to 7 cycles/ mm. To evaluate the performance of the detector under clinical conditions, an aneurysm model was placed over an anthropomorphic head phantom and a coil was guided into the aneurysm under fluoroscopic guidance using the detector. Image sequences from the procedure are presented demonstrating the high resolution of this SSXII.

  17. Long-term efficacy of a mini-course in radiation-reducing techniques in invasive cardiology

    Kuon, E. [Klinik Fraenkische Schweiz, Ebermannstadt (Germany). Abt. fuer Kardiologie; Empen, K.; Hummel, A.; Doerr, M.; Reffelmann, T.; Felix, S.B. [Ernst-Moritz-Arndt-Universitaet, Greifswald (Germany). Abt. fuer Innere Medizin B; Weitmann, K.; Hoffmann, W. [Ernst-Moritz-Arndt-Universitaet, Greifswald (Germany). Inst. fuer Versorgungsmedizin; Staudt, A. [Helios Kliniken, Schwerin (Germany). Abt. fuer Kardiologie und Angiologie


    Purpose: To validate the long-term efficacy of a 90-min. educational mini-course in less-irradiating cardiac interventional techniques. Materials and Methods: Before, two months after, and two years after the mini-course (periods I, II, and III), we analyzed the following radiation dose parameters for ten coronary angiographies (CA), performed by each of 7 cardiologists: total dose-area product (DAP), radiographic and fluoroscopic DAP fractions, number of radiographic frames and runs, and fluoroscopy time. Results: The median patient DAP for periods I, II and III was 31.4, 15.8 and 8.5 Gy x cm{sup 2}, respectively. The long-term effect was related to shorter median fluoroscopy times (180, 172, and 120 s), shorter (57, 52, and 45) and fewer (12, 12, and 10) radiographic runs, consistent collimation and restriction to an adequate image quality. Both radiographic DAP/frame (28.7, 17.0, and 18.4 mGy x cm{sup 2}) and fluoroscopic DAP/second (45.7, 24.2, and 10.0 mGy x cm{sup 2}) decreased significantly. The multivariate linear regression analysis confirmed the increasing efficacy of the mini-course itself (-44.6 and -60.7 %), and revealed a decreasing influence of the interventionalist's experience (-8.6 % and -4.9 % per 1,000 CAs, lifelong performed until the mini-course). The number of CAs performed after the mini-course did not influence the long-term DAP results. Conclusion: The presented educational mini-course allows a significant, long-lasting, and apparently ongoing reduction of patient radiation exposure due to CA. A self-surveillant documentation of relevant radiation parameters is well suited to monitor and improve each operator's individual long-term radiation-reducing efforts. (orig.)

  18. 3D model-based catheter tracking for motion compensation in EP procedures

    Brost, Alexander; Liao, Rui; Hornegger, Joachim; Strobel, Norbert


    Atrial fibrillation is the most common sustained heart arrhythmia and a leading cause of stroke. Its treatment by radio-frequency catheter ablation, performed using fluoroscopic image guidance, is gaining increasingly more importance. Two-dimensional fluoroscopic navigation can take advantage of overlay images derived from pre-operative 3-D data to add anatomical details otherwise not visible under X-ray. Unfortunately, respiratory motion may impair the utility of these static overlay images for catheter navigation. We developed an approach for image-based 3-D motion compensation as a solution to this problem. A bi-plane C-arm system is used to take X-ray images of a special circumferential mapping catheter from two directions. In the first step of the method, a 3-D model of the device is reconstructed. Three-dimensional respiratory motion at the site of ablation is then estimated by tracking the reconstructed catheter model in 3-D. This step involves bi-plane fluoroscopy and 2-D/3-D registration. Phantom data and clinical data were used to assess our model-based catheter tracking method. Experiments involving a moving heart phantom yielded an average 2-D tracking error of 1.4 mm and an average 3-D tracking error of 1.1 mm. Our evaluation of clinical data sets comprised 469 bi-plane fluoroscopy frames (938 monoplane fluoroscopy frames). We observed an average 2-D tracking error of 1.0 mm +/- 0.4 mm and an average 3-D tracking error of 0.8 mm +/- 0.5 mm. These results demonstrate that model-based motion-compensation based on 2-D/3-D registration is both feasible and accurate.

  19. A novel dosimeter for measuring the amount of radiation exposure of surgeons during percutaneous nephrolithotomy: Instadose™

    Yuruk, Emrah; Gureser, Gokhan; Tuken, Murat; Ertas, Kasim


    Introduction The aim of this study was to demonstrate the efficacy of Instadose™, a novel dosimeter designed for radiation workers to provide a measurement of the radiation dose at any time from any computer; to determine the amount of radiation exposure during percutaneous nephrolithotomy (PNL); and to evaluate the factors that affect the amount of radiation exposed. Material and methods Two experienced surgeons wore Instadose™ on the outer part of their lead aprons during the PNL procedures performed between December 2013 and July 2014. Patient demographics and stone characteristics were noted. Factors affecting radiation dose were determined. Fluoroscopic screening time was compared with the amount of radiation in order to validate the measurements of Instadose™. Results Overall, 51 patients with a mean age of 43.41 ±18.58 (range 1–75) years were enrolled. Male to female ratio was 35/16. The amount of radiation was greater than 0.01mSv in only 19 (37.25%) cases. Stone location complexity (p = 0.380), dilation type (p = 0.584), stone size (p = 0.565), dilation size (p = 0.891) and access number (p = 0.268) were not associated with increased radiation exposure. Instadose™ measurements were correlated with fluoroscopic screening time (r = 0.519, p = 0.001). Conclusions Instadose™ is a useful tool for the measurement of radiation exposure during PNL. The advantage of measuring the amount of radiation exposure after each PNL operation is that it may aid urologists in taking appropriate precautions to minimize the risk of radiation related complications. PMID:27551558

  20. Effectiveness of combined use of imprint cytological and histological examination in CT-guided tissue-core biopsy.

    Yamagami, Takuji; Yoshimatsu, Rika; Kajiwara, Kenji; Ishikawa, Masaki; Matsumoto, Tomohiro; Kakizawa, Hideaki; Toyoda, Naoyuki; Hasebe, Terumitsu; Awai, Kazuo


    This study evaluated the efficacy of the combination of imprint cytology and histology in tissue-core percutaneous biopsy under real-time computed tomography (CT) fluoroscopic guidance. Between October 2009 and June 2013, 156 percutaneous needle biopsies were performed in our institution. Those obtained by tissue-core biopsy underwent both imprint cytological and histological examinations routinely after touch imprint cytology was performed on site to evaluate the samples' sufficiency for cytological and pathological examination. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up. Rates of adequate specimens and precise diagnosis, by combined cytological and histological examination were 100 % (156/156) and 96.2 % (150/156), by cytology 94.4 % (152/156) and 83.3 % (130/156) and by histology 99.3 % (155/156) and 92.3 % (144/156). Precise diagnosis was achieved by combined examinations in 94.7 % (89/94) of thoracic lesions, 97.6 % (40/41) of musculoskeletal lesions, and 100 % (21/21) of abdominal, pelvic and retroperitoneal lesions. In all 104 lesions diagnosed as malignant by CT-guided biopsy and in 30 of 52 diagnosed as benign, specific cell types could be proved by combined examinations. Combined imprint cytology and histology performed after on-site touch imprint cytological evaluation improved the diagnostic ability of CT fluoroscopically guided biopsy. • CT-guided needle biopsy is a well-established diagnostic technique. • Touch imprint cytological evaluation on site is helpful in improving quality of CT-guided biopsy. • The rate of diagnosing malignant lymphoma specifically with cytological examination is relatively low. • The rate of specific diagnosis of benign lesion in musculoskeletal regions is low.

  1. Use of a Nitinol Wire Stent for Management of Severe Tracheal Stenosis in an Eclectus Parrot (Eclectus roratus).

    Mejia-Fava, Johanna; Holmes, Shannon P; Radlinsky, MaryAnn; Johnson, Dan; Ellis, Angela E; Mayer, Jörg; Schnellbacher, Rodney; Divers, Stephen J


    A 25-year-old, female eclectus parrot (Eclectus roratus) presented for dyspnea 3 weeks after anesthesia and surgery for egg yolk coelomitis. Radiography, computed tomography, and tracheoscopy revealed multiple tracheal strictures spanning a length of 2.6 cm in the mid to distal trachea. Histopathologic examination revealed mild fibrosis, inflammation, and hyperplasia consistent with acquired tracheal strictures. Tracheal resection was not considered possible because of the length of the affected trachea. The strictures were resected endoscopically, and repeated balloon dilation under fluoroscopic guidance over the course of 10 months resulted in immediate but unsustained improvement. Computed tomography was used to measure the stenotic area. A 4 × 36-mm, custom-made, nitinol wire stent was inserted into the trachea under fluoroscopic guidance. After stent placement, intermittent episodes of mild to moderate dyspnea continued, and these responded to nebulization with a combination of saline, acetylcysteine, and dexamethasone. Multiple attempts to wean the patient off nebulization therapy and to switch to a corticosteroid-free combination were unsuccessful. The parrot eventually developed complications, was euthanatized, and necropsy was performed. Histologically, the tracheal mucosa had widespread erosion to ulceration, with accumulation of intraluminal exudate and bacteria, severe degeneration of skeletal muscle and tracheal rings, prominent fibrosis, and mild to moderate, submucosal inflammation. Clinicopathologic findings in this case suggested tracheomalacia, which has not been previously described in birds. Custom-made tracheal stents can be used for severe tracheal stenosis in birds when tracheal resection and anastomosis is not possible. Complications of tracheal stent placement in birds may include tracheitis and tracheomalacia. To our knowledge, this is the first report of tracheal stent placement in an avian species.

  2. Venous air embolism in consecutive balloon kyphoplasties visualised on CT imaging

    Tins, Bernhard J.; Cassar-Pullicino, Victor N.; Lalam, Radhesh; Haddaway, Mike [Robert Jones and Agnes Hunt Orthopaedic Hospital, Department of Radiology, Oswestry, Shropshire (United Kingdom)


    We noted a large amount of intravenous gas during balloon kyphoplasty on CT imaging. Formal assessment to understand the extent, possible causes and implications was undertaken. Ten consecutive cases of balloon kyphoplasty were performed under general anaesthesia in the prone position, on a single vertebral level using a two-step technique under combined fluoroscopic and CT guidance. CT of the affected vertebra was performed before, after, and intermittently during the procedure. In 2 cases delayed CT was carried out in the supine position. Gas was seen on CT imaging, but not on conventional fluoroscopy. The gas is most likely to be air introduced during the procedure and was seen in the epidural and paravertebral venous plexus, posterior intercostal veins, renal veins, IVC and azygos vein. The average measured volume of gas seen on the post-procedure CT imaging was 1.07 mL, range 0.16-3.97 mL. There was no correlation of the measured amount of gas to the procedure duration or location, the use of a curette or the injected cement volume. Delayed CT in the supine position no longer showed air in the local venous system. Balloon kyphoplasty is associated with the fluoroscopically invisible introduction of air into the vertebral and paravertebral veins and deep systemic veins and is likely to be much more extensive than identified on CT imaging. There is potential for serious air embolism in kyphoplasty and if there is a sudden deterioration in patient condition during the procedure the possibility of this complication needs to be considered. (orig.)

  3. Intercostal Neuralgia Occurring as a Complication of Splanchnic Nerve Radiofrequency Ablation in a Patient with Chronic Pancreatitis.

    Tewari, Saipriya; Agarwal, Anil; Gautam, Sujeet K; Madabushi, Rajashree


    Our intent is to report a case of intercostal neuralgia occuring as a complication of splanchnic radiofreqency ablation (RFA), due to a breach in the integrity of the insulating sheath of the RFA needle.A 48-year-old man presented to our pain clinic with upper abdominal pain due to chronic pancreatitis, recalcitrant to medical management. We decided to perform bilateral splanchnic nerve RFA in this patient. After confirmation of bilateral correct needle placement under fluoroscopic guidance and sensorimotor testing, RFA was performed on the right side uneventfully. However, during RFA on the left side, the patient experienced severe pain in the epigastric region. A bolus of fentanyl 50 µg was given intravenously in order to minimise discomfort, and RFA was performed. In the post-procedure period, the patient described severe pain in the left subcostal and epigastric region, with features suggestive of intercostal neuralgia of the left 11th intercostal nerve. We went back and analysed all the fluoroscopic images again. Convinced of correct needle placement, we examined the RFA needles which had been used for ablation in this patient. One of the needles was discovered to have a fine breach in its insulating sheath, at a distance of approximately 30 mm from the active tip. It is of utmost importance for all interventional pain physicians to perform a thorough pre-use check of the equipment prior to any RFA procedure, with special emphasis on ensuring the integrity of the insulating sheath of the needles which are to be used, in order to prevent injury of non target nerves. Splanchnic nerve block, radiofrequency ablation, intercostal neuralgia, radiofrequency ablation complications, radiofrequency equipment check, radiofrequency needle.

  4. Percutaneous vertebroplasty: Multi-centric results from EVEREST experience in large cohort of patients

    Anselmetti, Giovanni Carlo, E-mail: [Interventional Radiology Unit, Institute for Cancer Research and Treatment, Strada Provinciale No. 142, Km. 3, 95, 10060 Candiolo, Turin (Italy); Marcia, Stefano, E-mail: [Radiology Unit, ASL8 Cagliari, SS. Trinità Hospital, Via Is Mirrionis 92, 09121 Cagliari (Italy); Saba, Luca, E-mail: [Radiology Unit, University of Cagliari, Policlinico Universitario, ss 554, Monserrato, 09127 Cagliari (Italy); Muto, Mario, E-mail: [Neuroradiology Unit, AORN Cardarelli, Via A. Cardarelli No. 9, 80131 Napoli (Italy); Bonaldi, Giuseppe, E-mail: [Neuroradiology Unit, Riuniti di Bergamo, Largo Barozzi, 124128 Bergamo (Italy); Carpeggiani, Paolo, E-mail: [Neuroradiology Unit, Policlinico di Modena, Via Dal Pozzo 17, Modena (Italy); Marini, Stefano, E-mail: [Radiology Unit, University of Cagliari, San Giovanni di Dio Hospital, Via Ospedale 46, 09127 Cagliari (Italy); Manca, Antonio, E-mail: [Interventional Radiology Unit, Institute for Cancer Research and Treatment, Strada Provinciale No. 142, Km. 3, 95, 10060 Candiolo, Turin (Italy); Masala, Salvatore, E-mail: [Radiology Unit, Diagnostic Imaging Department, University of Rome Tor Vergata, Roma (Italy)


    Purpose: The purpose of this study was to prospectively evaluate results and complications of percutaneous vertebroplasty (PV) performed in 6 different Italian Centres belonging to the European VErtebroplasty RESearch Team (E.VE.RES.T) in a large series of patients. Materials and methods: Follow-up was obtained in 4547 patients (3211 females and 1336 males; mean age 70.2 years) that underwent PV for a total of 13.437 treated vertebrae. Procedures were performed by using fluoroscopic guidance or combined CT-fluoroscopic guidance. All patients underwent PV in local anaesthesia except for second cervical vertebrae treated with a trans-oral approach that required general anaesthesia. Results: 4004 out of 4547 (88.0%) patients reported significant pain relief (difference > or = 2 point in pain evaluated with an 11-point visual analogue scale; p < 0.0001) within 48 h: an average of 7.7 ± 0.4 dropped to 1.8 ± 0.6 in the osteoporotic patients; 8.3 ± 0.4 to 2.4 ± 0.4 in metastases; 8.3 ± 0.4 to 1.7 ± 1.0 in myeloma; 6.2 ± 3.5 to 0.3 ± 0.2 in angioma and 7.4 ± 0.4 to 1.4 ± 0.9 in trauma. 430 osteoporotic patients (13%) were retreated for a subsequent fracture; in 302/430 patients (70.2%), the new fracture occurred in the contiguous vertebra. No major neurologic complications were reported and the most frequent minor complication was venous leakage (20.5%). Conclusions: This large series of patients confirms that percutaneous vertebroplasty is an effective and safe procedure in the treatment of vertebral fractures. Best results are obtained in the treatment of myeloma and trauma.

  5. Evaluation of an X-Ray Dose Profile Derived from an Optically Stimulated Luminescent Dosimeter during Computed Tomographic Fluoroscopy.

    Hiroaki Hasegawa

    Full Text Available The purpose of this study was to evaluate scatter radiation dose to the subject surface during X-ray computed tomography (CT fluoroscopy using the integrated dose ratio (IDR of an X-ray dose profile derived from an optically stimulated luminescent (OSL dosimeter. We aimed to obtain quantitative evidence supporting the radiation protection methods used during previous CT fluoroscopy. A multislice CT scanner was used to perform this study. OSL dosimeters were placed on the top and the lateral side of the chest phantom so that the longitudinal direction of dosimeters was parallel to the orthogonal axis-to-slice plane for measurement of dose profiles in CT fluoroscopy. Measurement of fluoroscopic conditions was performed at 120 kVp and 80 kVp. Scatter radiation dose was evaluated by calculating the integrated dose determined by OSL dosimetry. The overall percent difference of the integrated doses between OSL dosimeters and ionization chamber was 5.92%. The ratio of the integrated dose of a 100-mm length area to its tails (-50 to -6 mm, 50 to 6 mm was the lowest on the lateral side at 80 kVp and the highest on the top at 120 kVp. The IDRs for different measurement positions were larger at 120 kVp than at 80 kVp. Similarly, the IDRs for the tube voltage between the primary X-ray beam and scatter radiation was larger on the lateral side than on the top of the phantom. IDR evaluation suggested that the scatter radiation dose has a high dependence on the position and a low dependence on tube voltage relative to the primary X-ray beam for constant dose rate fluoroscopic conditions. These results provided quantitative evidence supporting the radiation protection methods used during CT fluoroscopy in previous studies.

  6. Our initial experience with percutaneous nephrolithotomy in children

    Mehmet Hanifi Okur


    Full Text Available Objective: To present our initial experience on percutaneous nephrolithotomy (PCNL in children between March 2012 and November 2013. Methods: 13 renal units of 12 patients underwent PCNL. Patients were evaluated in terms of age, preoperatively in terms of urine, blood count, urine culture, serum biochemical, and routine coagulation tests and radiological examinations, stone location, stone burden (according to plain radiograph, preoperative use of nephrostomy and average fluoroscopic manipulation time. To facilitate access, prior mechanical dilatation was performed nephrostomy access tract. After the PCNL procedure, we placed nephrostomy in all patients postoperatively. They were evaluated with regard to residual stone, complications (according to the Clavien classification and outcomes. Results: Average age was 11 years (6-15. There was no abnormality in Laboratory Screening. Location of 11 stones was renal pelvis and 2 stones was pelvis + calyx. The average stone size was 260 mm². Preoperative acces were provided in 3 patients, others were intraoperatively. Average fluoroscopic manipulation time was 4,8 minutes (2-11. At the first postoperative day, 11 (85 % patients achieved a completely stone-free state. Complications were seen in 3 patients; failure of renal access in one patient (Grade 3b, urine leakage was observed after surgery in one (Grade 3a, postoperative blood transfusion required in one patient (Grade 2. The hospital stay duration was 5,5 days (5-7 days. Conclusions: Pediatric PCNL is a minimal invasive procedure which provides high rate of stone free and good cosmetics. İf there is adequate facilities and equipment with experienced persons, this procedure can easily be used in pediatric surgery clinics.

  7. Radiofrequency ablation of the basivertebral nerve as potential treatment of back pain: pathologic assessment in an ovine model (Invited Paper)

    Hoopes, P. J.; Eskey, Cliff J.; Attawia, Mohammed; Patel, Samit J.; Ryan, T. P.; Pellegrino, Richard; Bergeron, Jeffrey A.


    Pathological involvement of the basivertebral nerve (BVN), an intraosseous vertebral nerve, may play a significant role in some forms of back pain. This study was designed to assess the feasibility and effects of thermal ablation of the lumbar basivertebral nerve in mature sheep. Sixteen adult female sheep weighing 65-80 kg were anesthetized and positioned for ventral recumbent surgery. Under fluoroscopic guidance, two bilarterally oposed 5mm active length rediofrequency (RF) electrodes (1.65mm diameter were perfutaneously placed in select lumbar vertebrae at a relative angle of 70 degrees with a 5 mm tip separation. The elctrodes were advanced to the region of the vertebral bodies which contained the BVN. A thermal dose of 95° C/720 seconds was administered. Animals were survived for 2, 14, 90, or 180 days post-treatment. Clinical, radiologic and pathologic investigations were performed to determine the effect of the heat on the BVN and associated tissues. Thermal damage to the basivertebral neurovascular bundle was characterized by early hemorrhage and necrosis, followed by inflammation and fibrosis. Although there wasa significant revascularization of the treated bone marow regions, there was no evidence of basivertebral nerve survival or regeneration regeneration. In addition to ablation of teh basivertebral nerovascular bundle, the areas receiving the greatest treatment demonstrated initial mild local osteolysis and demineralization of the vertebral body bone and regional depopulation of the vertebral bone marrow cellular elements. Significant bone remodeling in the affected areas had begun by 14 days post-treatment. Bone remodeling was characterized by conventional osteoblast proliferation, osteoid deposition, and mineralization. This study demonstrated the ability to accurately, reproducibly, and safely ablate the basivertebral nerve and neurovascular bundle in mature sheep using a fluoroscopically guided percutaneously delivered radiofrequency technique.

  8. Outcome of Percutaneous Lumbar Synovial Cyst Rupture in Patients with Lumbar Radiculopathy.

    Eshraghi, Yashar; Desai, Vimal; Cajigal Cajigal, Calvin; Tabbaa, Kutaiba


    Lumbar synovial cysts can result from spondylosis of facet joints. These cysts can encroach on adjacent nerve roots, causing symptoms of radiculopathy. Currently the only definitive treatment for these symptoms is surgery, which may involve laminectomy or laminotomy, with or without spinal fusion. Surgery has been reported to successfully relieve radicular pain in 83.5% of patients by Zhenbo et al. Little information is available concerning the efficacy and outcome of percutaneous fluoroscopic synovial cyst rupture for treatment of facet joint synovial cysts. The goal of this investigation was to assess the efficacy of fluoroscopically guided lumbar synovial cyst rupture, in particular for its relief of radicular symptoms and its potential to reduce the need for surgical intervention. Retrospective evaluation of a case series. University hospital and urban public health care system. With approval from the Institutional Review Board of Case Western Reserve University/ MetroHealth Medical Center, we reviewed the medical charts of patients with lumbar radiculopathy who underwent percutaneous lumbar synovial cyst rupture. The 30 patients in the cohort were treated by one pain specialist between 2006 and 2013. These patients were diagnosed with moderate to severe lower back pain, radiculopathy, and ranged in age from 42 to 80 years. Patients were followed up for a minimum of 6 months and up to 24 months. Pre- and post-procedure pain assessments were reviewed by clinical chart review. In addition post-procedure pain assessments and duration of pain relief were obtained with telephone interviews. Pain had been reported by the patients using a numeric rating scale of 0 - 10 (0 = no pain; 10 = worst possible pain). Charts were reviewed to determine if surgery was eventually performed to correct radicular symptoms. More than 6 months of pain relief was achieved in 14/30 patients (46%) and between one and 6 months of pain relief was achieved in 7/30 patients (23.3%). Nine

  9. 3D delivered dose assessment using a 4DCT-based motion model

    Cai, Weixing; Hurwitz, Martina H.; Williams, Christopher L.; Dhou, Salam; Berbeco, Ross I.; Mishra, Pankaj, E-mail:, E-mail:; Lewis, John H., E-mail:, E-mail: [Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Seco, Joao [Francis H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02115 (United States)


    Purpose: The purpose of this work is to develop a clinically feasible method of calculating actual delivered dose distributions for patients who have significant respiratory motion during the course of stereotactic body radiation therapy (SBRT). Methods: A novel approach was proposed to calculate the actual delivered dose distribution for SBRT lung treatment. This approach can be specified in three steps. (1) At the treatment planning stage, a patient-specific motion model is created from planning 4DCT data. This model assumes that the displacement vector field (DVF) of any respiratory motion deformation can be described as a linear combination of some basis DVFs. (2) During the treatment procedure, 2D time-varying projection images (either kV or MV projections) are acquired, from which time-varying “fluoroscopic” 3D images of the patient are reconstructed using the motion model. The DVF of each timepoint in the time-varying reconstruction is an optimized linear combination of basis DVFs such that the 2D projection of the 3D volume at this timepoint matches the projection image. (3) 3D dose distribution is computed for each timepoint in the set of 3D reconstructed fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach was first validated using two modified digital extended cardio-torso (XCAT) phantoms with lung tumors and different respiratory motions. The estimated doses were compared to the dose that would be calculated for routine 4DCT-based planning and to the actual delivered dose that was calculated using “ground truth” XCAT phantoms at all timepoints. The approach was also tested using one set of patient data, which demonstrated the application of our method in a clinical scenario. Results: For the first XCAT phantom that has a mostly regular breathing pattern, the errors in 95% volume dose (D95) are 0.11% and 0.83%, respectively for 3D fluoroscopic images