WorldWideScience

Sample records for epid cine images

  1. Verification of the linac isocenter for stereotactic radiosurgery using cine-EPID imaging and arc delivery

    International Nuclear Information System (INIS)

    Rowshanfarzad, Pejman; Sabet, Mahsheed; O' Connor, Daryl J.; Greer, Peter B.

    2011-01-01

    Purpose:Verification of the mechanical isocenter position is required as part of comprehensive quality assurance programs for stereotactic radiosurgery/radiotherapy (SRS/SRT) treatments. Several techniques have been proposed for this purpose but each of them has certain drawbacks. In this paper, a new efficient and more comprehensive method using cine-EPID images has been introduced for automatic verification of the isocenter with sufficient accuracy for stereotactic applications. Methods: Using a circular collimator fixed to the gantry head to define the field, EPID images of a Winston-Lutz phantom were acquired in cine-imaging mode during 360 deg. gantry rotations. A robust matlab code was developed to analyze the data by finding the center of the field and the center of the ball bearing shadow in each image with sub-pixel accuracy. The distance between these two centers was determined for every image. The method was evaluated by comparison to results of a mechanical pointer and also by detection of a manual shift applied to the phantom position. The repeatability and reproducibility of the method were tested and it was also applied to detect couch and collimator wobble during rotation. Results:The accuracy of the algorithm was 0.03 ± 0.02 mm. The repeatability was less than 3 μm and the reproducibility was less than 86 μm. The time elapsed for the analysis of more than 100 cine images of Varian aS1000 and aS500 EPIDs were ∼65 and 20 s, respectively. Processing of images taken in integrated mode took 0.1 s. The output of the analysis software is printable and shows the isocenter shifts as a function of angle in both in-plane and cross-plane directions. It gives warning messages where the shifts exceed the criteria for SRS/SRT and provides useful data for the necessary adjustments in the system including bearing system and/or room lasers. Conclusions: The comprehensive method introduced in this study uses cine-images, is highly accurate, fast, and independent

  2. The impact of cine EPID image acquisition frame rate on markerless soft-tissue tracking

    International Nuclear Information System (INIS)

    Yip, Stephen; Rottmann, Joerg; Berbeco, Ross

    2014-01-01

    Purpose: Although reduction of the cine electronic portal imaging device (EPID) acquisition frame rate through multiple frame averaging may reduce hardware memory burden and decrease image noise, it can hinder the continuity of soft-tissue motion leading to poor autotracking results. The impact of motion blurring and image noise on the tracking performance was investigated. Methods: Phantom and patient images were acquired at a frame rate of 12.87 Hz with an amorphous silicon portal imager (AS1000, Varian Medical Systems, Palo Alto, CA). The maximum frame rate of 12.87 Hz is imposed by the EPID. Low frame rate images were obtained by continuous frame averaging. A previously validated tracking algorithm was employed for autotracking. The difference between the programmed and autotracked positions of a Las Vegas phantom moving in the superior-inferior direction defined the tracking error (δ). Motion blurring was assessed by measuring the area change of the circle with the greatest depth. Additionally, lung tumors on 1747 frames acquired at 11 field angles from four radiotherapy patients are manually and automatically tracked with varying frame averaging. δ was defined by the position difference of the two tracking methods. Image noise was defined as the standard deviation of the background intensity. Motion blurring and image noise are correlated with δ using Pearson correlation coefficient (R). Results: For both phantom and patient studies, the autotracking errors increased at frame rates lower than 4.29 Hz. Above 4.29 Hz, changes in errors were negligible withδ < 1.60 mm. Motion blurring and image noise were observed to increase and decrease with frame averaging, respectively. Motion blurring and tracking errors were significantly correlated for the phantom (R = 0.94) and patient studies (R = 0.72). Moderate to poor correlation was found between image noise and tracking error with R −0.58 and −0.19 for both studies, respectively. Conclusions: Cine EPID

  3. Computerized method for estimation of the location of a lung tumor on EPID cine images without implanted markers in stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Arimura, H; Toyofuku, F; Higashida, Y; Onizuka, Y; Terashima, H; Egashira, Y; Shioyama, Y; Nomoto, S; Honda, H; Nakamura, K; Yoshidome, S; Anai, S

    2009-01-01

    The purpose of this study was to develop a computerized method for estimation of the location of a lung tumor in cine images on an electronic portal imaging device (EPID) without implanted markers during stereotactic body radiotherapy (SBRT). Each tumor region was segmented in the first EPID cine image, i.e., reference portal image, based on a multiple-gray level thresholding technique and a region growing technique, and then the image including the tumor region was cropped as a 'tumor template' image. The tumor location was determined as the position in which the tumor template image took the maximum cross-correlation value within each consecutive portal image, which was acquired in cine mode on the EPID in treatment. EPID images with 512 x 384 pixels (pixel size: 0.56 mm) were acquired at a sampling rate of 0.5 frame s -1 by using energies of 4, 6 or 10 MV on linear accelerators. We applied our proposed method to EPID cine images (226 frames) of 12 clinical cases (ages: 51-83, mean: 72) with a non-small cell lung cancer. As a result, the average location error between tumor points obtained by our method and the manual method was 1.47 ± 0.60 mm. This preliminary study suggests that our method based on the tumor template matching technique might be feasible for tracking the location of a lung tumor without implanted markers in SBRT.

  4. SU-E-J-112: The Impact of Cine EPID Image Acquisition Frame Rate On Markerless Soft-Tissue Tracking

    International Nuclear Information System (INIS)

    Yip, S; Rottmann, J; Berbeco, R

    2014-01-01

    Purpose: Although reduction of the cine EPID acquisition frame rate through multiple frame averaging may reduce hardware memory burden and decrease image noise, it can hinder the continuity of soft-tissue motion leading to poor auto-tracking results. The impact of motion blurring and image noise on the tracking performance was investigated. Methods: Phantom and patient images were acquired at a frame rate of 12.87Hz on an AS1000 portal imager. Low frame rate images were obtained by continuous frame averaging. A previously validated tracking algorithm was employed for auto-tracking. The difference between the programmed and auto-tracked positions of a Las Vegas phantom moving in the superior-inferior direction defined the tracking error (δ). Motion blurring was assessed by measuring the area change of the circle with the greatest depth. Additionally, lung tumors on 1747 frames acquired at eleven field angles from four radiotherapy patients are manually and automatically tracked with varying frame averaging. δ was defined by the position difference of the two tracking methods. Image noise was defined as the standard deviation of the background intensity. Motion blurring and image noise were correlated with δ using Pearson correlation coefficient (R). Results: For both phantom and patient studies, the auto-tracking errors increased at frame rates lower than 4.29Hz. Above 4.29Hz, changes in errors were negligible with δ<1.60mm. Motion blurring and image noise were observed to increase and decrease with frame averaging, respectively. Motion blurring and tracking errors were significantly correlated for the phantom (R=0.94) and patient studies (R=0.72). Moderate to poor correlation was found between image noise and tracking error with R -0.58 and -0.19 for both studies, respectively. Conclusion: An image acquisition frame rate of at least 4.29Hz is recommended for cine EPID tracking. Motion blurring in images with frame rates below 4.39Hz can substantially reduce the

  5. Verification of respiratory-gated radiotherapy with new real-time tumour-tracking radiotherapy system using cine EPID images and a log file.

    Science.gov (United States)

    Shiinoki, Takehiro; Hanazawa, Hideki; Yuasa, Yuki; Fujimoto, Koya; Uehara, Takuya; Shibuya, Keiko

    2017-02-21

    A combined system comprising the TrueBeam linear accelerator and a new real-time tumour-tracking radiotherapy system, SyncTraX, was installed at our institution. The objectives of this study are to develop a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine electronic portal image device (EPID) images and a log file and to verify this treatment in clinical cases. Respiratory-gated radiotherapy was performed using TrueBeam and the SyncTraX system. Cine EPID images and a log file were acquired for a phantom and three patients during the course of the treatment. Digitally reconstructed radiographs (DRRs) were created for each treatment beam using a planning CT set. The cine EPID images, log file, and DRRs were analysed using a developed software. For the phantom case, the accuracy of the proposed method was evaluated to verify the respiratory-gated radiotherapy. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker used as an internal surrogate were calculated to evaluate the gating accuracy and set-up uncertainty in the superior-inferior (SI), anterior-posterior (AP), and left-right (LR) directions. The proposed method achieved high accuracy for the phantom verification. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker were  ⩽3 mm and  ±3 mm in the SI, AP, and LR directions. We proposed a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine EPID images and a log file and showed that this treatment is performed with high accuracy in clinical cases.

  6. Verification of respiratory-gated radiotherapy with new real-time tumour-tracking radiotherapy system using cine EPID images and a log file

    Science.gov (United States)

    Shiinoki, Takehiro; Hanazawa, Hideki; Yuasa, Yuki; Fujimoto, Koya; Uehara, Takuya; Shibuya, Keiko

    2017-02-01

    A combined system comprising the TrueBeam linear accelerator and a new real-time tumour-tracking radiotherapy system, SyncTraX, was installed at our institution. The objectives of this study are to develop a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine electronic portal image device (EPID) images and a log file and to verify this treatment in clinical cases. Respiratory-gated radiotherapy was performed using TrueBeam and the SyncTraX system. Cine EPID images and a log file were acquired for a phantom and three patients during the course of the treatment. Digitally reconstructed radiographs (DRRs) were created for each treatment beam using a planning CT set. The cine EPID images, log file, and DRRs were analysed using a developed software. For the phantom case, the accuracy of the proposed method was evaluated to verify the respiratory-gated radiotherapy. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker used as an internal surrogate were calculated to evaluate the gating accuracy and set-up uncertainty in the superior-inferior (SI), anterior-posterior (AP), and left-right (LR) directions. The proposed method achieved high accuracy for the phantom verification. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker were  ⩽3 mm and  ±3 mm in the SI, AP, and LR directions. We proposed a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine EPID images and a log file and showed that this treatment is performed with high accuracy in clinical cases. This work was partly presented at the 58th Annual meeting of American Association of Physicists in Medicine.

  7. Frame average optimization of cine-mode EPID images used for routine clinical in vivo patient dose verification of VMAT deliveries

    International Nuclear Information System (INIS)

    McCowan, P. M.; McCurdy, B. M. C.

    2016-01-01

    Purpose: The in vivo 3D dose delivered to a patient during volumetric modulated arc therapy (VMAT) delivery can be calculated using electronic portal imaging device (EPID) images. These images must be acquired in cine-mode (i.e., “movie” mode) in order to capture the time-dependent delivery information. The angle subtended by each cine-mode EPID image during an arc can be changed via the frame averaging number selected within the image acquisition software. A large frame average number will decrease the EPID’s angular resolution and will result in a decrease in the accuracy of the dose information contained within each image. Alternatively, less EPID images acquired per delivery will decrease the overall 3D patient dose calculation time, which is appealing for large-scale clinical implementation. Therefore, the purpose of this study was to determine the optimal frame average value per EPID image, defined as the highest frame averaging that can be used without an appreciable loss in 3D dose reconstruction accuracy for VMAT treatments. Methods: Six different VMAT plans and six different SBRT-VMAT plans were delivered to an anthropomorphic phantom. Delivery was carried out on a Varian 2300ix model linear accelerator (Linac) equipped with an aS1000 EPID running at a frame acquisition rate of 7.5 Hz. An additional PC was set up at the Linac console area, equipped with specialized frame-grabber hardware and software packages allowing continuous acquisition of all EPID frames during delivery. Frames were averaged into “frame-averaged” EPID images using MATLAB. Each frame-averaged data set was used to calculate the in vivo dose to the patient and then compared to the single EPID frame in vivo dose calculation (the single frame calculation represents the highest possible angular resolution per EPID image). A mean percentage dose difference of low dose (<20% prescription dose) and high dose regions (>80% prescription dose) was calculated for each frame averaged

  8. Frame average optimization of cine-mode EPID images used for routine clinical in vivo patient dose verification of VMAT deliveries

    Energy Technology Data Exchange (ETDEWEB)

    McCowan, P. M., E-mail: pmccowan@cancercare.mb.ca [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada and Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); McCurdy, B. M. C. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Radiology, University of Manitoba, 820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9 (Canada)

    2016-01-15

    Purpose: The in vivo 3D dose delivered to a patient during volumetric modulated arc therapy (VMAT) delivery can be calculated using electronic portal imaging device (EPID) images. These images must be acquired in cine-mode (i.e., “movie” mode) in order to capture the time-dependent delivery information. The angle subtended by each cine-mode EPID image during an arc can be changed via the frame averaging number selected within the image acquisition software. A large frame average number will decrease the EPID’s angular resolution and will result in a decrease in the accuracy of the dose information contained within each image. Alternatively, less EPID images acquired per delivery will decrease the overall 3D patient dose calculation time, which is appealing for large-scale clinical implementation. Therefore, the purpose of this study was to determine the optimal frame average value per EPID image, defined as the highest frame averaging that can be used without an appreciable loss in 3D dose reconstruction accuracy for VMAT treatments. Methods: Six different VMAT plans and six different SBRT-VMAT plans were delivered to an anthropomorphic phantom. Delivery was carried out on a Varian 2300ix model linear accelerator (Linac) equipped with an aS1000 EPID running at a frame acquisition rate of 7.5 Hz. An additional PC was set up at the Linac console area, equipped with specialized frame-grabber hardware and software packages allowing continuous acquisition of all EPID frames during delivery. Frames were averaged into “frame-averaged” EPID images using MATLAB. Each frame-averaged data set was used to calculate the in vivo dose to the patient and then compared to the single EPID frame in vivo dose calculation (the single frame calculation represents the highest possible angular resolution per EPID image). A mean percentage dose difference of low dose (<20% prescription dose) and high dose regions (>80% prescription dose) was calculated for each frame averaged

  9. Epid cine acquisition mode for in vivo dosimetry in dynamic arc radiation therapy

    International Nuclear Information System (INIS)

    Fidanzio, Andrea; Mameli, Alessandra; Placidi, Elisa; Greco, Francesca; Stimato, Gerardina; Gaudino, Diego; Ramella, Sara; D'Angelillo, Rolando; Cellini, Francesco; Trodella, Lucio; Cilla, Savino; Grimaldi, Luca; D'Onofrio, Guido; Azario, Luigi; Piermattei, Angelo

    2008-01-01

    In this paper the cine acquisition mode of an electronic portal imaging device (EPID) has been calibrated and tested to determine the in vivo dose for dynamic conformal arc radiation therapy (DCAT). The EPID cine acquisition mode, that allows a frame acquisition rate of one image every 1.66 s, was studied with a monitor unit rate equal to 100 UM/min. In these conditions good signal stability, ±1% (2SD) evaluated during three months, signal reproducibility within ±0.8% (2SD) and linearity with dose and dose rate within ±1% (2SD) were obtained. The transit signal, S t , (due to the transmitted beam below the phantom) measured by the EPID cine acquisition mode was used to determine, (i) a set of correlation functions, F(w,L), defined as the ratio between S t and the dose at half thickness, D m , measured in solid water phantoms of different thicknesses, w and with square fields of side L, (ii) a set of factors, f(d,L), that take into account the different X-ray scatter contribution from the phantom to the S t signal as a function of the variation, d, of the air gap between the phantom and the EPID. The reconstruction of the isocenter dose, D iso , for DCAT was obtained convolving the transit signal values, obtained at different gantry angles, with the respective reconstruction factors determined by a house-made software. The method was tested with cylindrical and anthropomorphic phantoms and the results show that the reconstructed D iso values can be obtained with an accuracy within ±2.5% in cylindrical phantom and within ±3.4% for anthropomorphic phantom. In conclusion, the transit dosimetry by EPID was assessed to be adequate to perform DCAT in vivo dosimetry, that is not realizable with the other traditional techniques. Moreover, the method proposed here could be implemented to supply in vivo dose values in real time

  10. SU-F-T-263: Dosimetric Characteristics of the Cine Acquisition Mode of An A-Si EPID

    Energy Technology Data Exchange (ETDEWEB)

    Bawazeer, O; Deb, P [RMIT University, Melbourne, VIC (Australia); Sarasanandarajah, S [Peter MacCallum Cancer Institute, Melbourne, Victoria (Australia); Herath, S; Kron, T [Peter MacCallum Cancer Institute, Melbourne, VIC (Australia)

    2016-06-15

    Purpose: To investigate the dosimetric characteristics of Varian a-Si-500 electronic portal imaging device (EPID) operated in cine mode particularly considering linearity with delivered dose, dose rate, field size, phantom thickness, MLC speed and common IMRT fields. Methods: The EPID that attached to a Varian Clinac 21iX linear accelerator, was irradiated with 6 and 18 MV using 600 MU/min. Image acquisition is controlled by the IAS3 software, Trigger delay was 6 ms, BeamOnDelay and FrameStartDelay were zero. Different frame rates were utilized. Cine mode response was calculated using MATLAB as summation of mean pixel values in a region of interest of the acquired images. The performance of cine mode was compared to integrated mode and dose measurements in water using CC13 ionization chamber. Results: Figure1 illustrates that cine mode has nonlinear response for small MU, when delivering 10 MU was about 0.5 and 0.64 for 6 and 18 MV respectively. This is because the missing acquired images that were calculated around four images missing in each delivery. With the increase MU the response became linear and comparable with integrated mode and ionization chamber within 2%. Figure 2 shows that cine mode has comparable response with integrated mode and ionization chamber within 2% with changing dose rate for 10 MU delivered. This indicates that the dose rate change has no effect on nonlinearity of cine mode response. Except nonlinearity, cine mode is well matched to integrated mode response within 2% for field size, phantom thickness, MLC speed dependences. Conclusion: Cine mode has similar dosimetric characteristics to integrated mode with open and IMRT fields, and the main limitation with cine mode is missing images. Therefore, the calibration of EPID images with this mode should be run with large MU, and when IMRT verification field has low MU, the correction for missing images are required.

  11. SU-F-T-263: Dosimetric Characteristics of the Cine Acquisition Mode of An A-Si EPID

    International Nuclear Information System (INIS)

    Bawazeer, O; Deb, P; Sarasanandarajah, S; Herath, S; Kron, T

    2016-01-01

    Purpose: To investigate the dosimetric characteristics of Varian a-Si-500 electronic portal imaging device (EPID) operated in cine mode particularly considering linearity with delivered dose, dose rate, field size, phantom thickness, MLC speed and common IMRT fields. Methods: The EPID that attached to a Varian Clinac 21iX linear accelerator, was irradiated with 6 and 18 MV using 600 MU/min. Image acquisition is controlled by the IAS3 software, Trigger delay was 6 ms, BeamOnDelay and FrameStartDelay were zero. Different frame rates were utilized. Cine mode response was calculated using MATLAB as summation of mean pixel values in a region of interest of the acquired images. The performance of cine mode was compared to integrated mode and dose measurements in water using CC13 ionization chamber. Results: Figure1 illustrates that cine mode has nonlinear response for small MU, when delivering 10 MU was about 0.5 and 0.64 for 6 and 18 MV respectively. This is because the missing acquired images that were calculated around four images missing in each delivery. With the increase MU the response became linear and comparable with integrated mode and ionization chamber within 2%. Figure 2 shows that cine mode has comparable response with integrated mode and ionization chamber within 2% with changing dose rate for 10 MU delivered. This indicates that the dose rate change has no effect on nonlinearity of cine mode response. Except nonlinearity, cine mode is well matched to integrated mode response within 2% for field size, phantom thickness, MLC speed dependences. Conclusion: Cine mode has similar dosimetric characteristics to integrated mode with open and IMRT fields, and the main limitation with cine mode is missing images. Therefore, the calibration of EPID images with this mode should be run with large MU, and when IMRT verification field has low MU, the correction for missing images are required.

  12. Cine EPID evaluation of two non-commercial techniques for DIBH

    International Nuclear Information System (INIS)

    Jensen, Christopher; Urribarri, Jaime; Cail, Daniel; Rottmann, Joerg; Mishra, Pankaj; Lingos, Tatiana; Niedermayr, Thomas; Berbeco, Ross

    2014-01-01

    Purpose: To evaluate the efficacy of two noncommercial techniques for deep inspiration breathhold (DIBH) treatment of left-sided breast cancer (LSBC) usingcine electronic portal imaging device (EPID) images. Methods: 23 875 EPID images of 65 patients treated for LSBC at two different cancer treatment centers were retrieved. At the Milford Regional Cancer Center, DIBH stability was maintained by visual alignment of inroom lasers and patient skin tattoos (TAT). At the South Shore Hospital, a distance-measuring laser device (RTSSD) was implemented. For both centers,cine EPID images were acquired at least once per week during beam-on. Chest wall position relative to image boundary was measured and tracked over the course of treatment for every patient and treatment fraction for which data were acquired. Results: Median intrabeam chest motion was 0.31 mm for the TAT method and 0.37 mm for the RTSSD method. The maximum excursions exceeded our treatment protocol threshold of 3 mm in 0.3% of cases (TAT) and 1.2% of cases (RTSSD). The authors did not observe a clinically significant difference between the two datasets. Conclusions: Both noncommercial techniques for monitoring the DIBH location provided DIBH stability within the predetermined treatment protocol parameters (<3 mm). The intreatment imaging offered by the EPID operating incine mode facilitates retrospective analysis and validation of both techniques

  13. Cine EPID evaluation of two non-commercial techniques for DIBH

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Christopher; Urribarri, Jaime; Cail, Daniel; Rottmann, Joerg; Mishra, Pankaj; Lingos, Tatiana; Niedermayr, Thomas; Berbeco, Ross, E-mail: rberbeco@lroc.harvard.edu [Brigham and Women' s Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2014-02-15

    Purpose: To evaluate the efficacy of two noncommercial techniques for deep inspiration breathhold (DIBH) treatment of left-sided breast cancer (LSBC) usingcine electronic portal imaging device (EPID) images. Methods: 23 875 EPID images of 65 patients treated for LSBC at two different cancer treatment centers were retrieved. At the Milford Regional Cancer Center, DIBH stability was maintained by visual alignment of inroom lasers and patient skin tattoos (TAT). At the South Shore Hospital, a distance-measuring laser device (RTSSD) was implemented. For both centers,cine EPID images were acquired at least once per week during beam-on. Chest wall position relative to image boundary was measured and tracked over the course of treatment for every patient and treatment fraction for which data were acquired. Results: Median intrabeam chest motion was 0.31 mm for the TAT method and 0.37 mm for the RTSSD method. The maximum excursions exceeded our treatment protocol threshold of 3 mm in 0.3% of cases (TAT) and 1.2% of cases (RTSSD). The authors did not observe a clinically significant difference between the two datasets. Conclusions: Both noncommercial techniques for monitoring the DIBH location provided DIBH stability within the predetermined treatment protocol parameters (<3 mm). The intreatment imaging offered by the EPID operating incine mode facilitates retrospective analysis and validation of both techniques.

  14. Epid cine acquisition mode for in vivo dosimetry in dynamic arc radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Fidanzio, Andrea [U.O. di Fisica Sanitaria Policlinico A. Gemelli, Universita Cattolica S. Cuore, Rome (Italy)], E-mail: andrea.fidanzio@rm.unicatt.it; Mameli, Alessandra; Placidi, Elisa; Greco, Francesca [U.O. di Fisica Sanitaria Policlinico A. Gemelli, Universita Cattolica S. Cuore, Rome (Italy); Stimato, Gerardina; Gaudino, Diego; Ramella, Sara; D' Angelillo, Rolando; Cellini, Francesco; Trodella, Lucio [U.O. di Radioterapia, Universita Campus Bio-Medico, Rome (Italy); Cilla, Savino; Grimaldi, Luca; D' Onofrio, Guido [U.O. di Fisica Sanitaria, Centro di Ricerca e Formazione ad Alta Tecnologia nelle Scienze Biomediche dell' Universita Cattolica S. Cuore, Campobasso (Italy); Azario, Luigi; Piermattei, Angelo [Istituto di Fisica, Universita Cattolica del S. Cuore, Rome (Italy)

    2008-02-15

    In this paper the cine acquisition mode of an electronic portal imaging device (EPID) has been calibrated and tested to determine the in vivo dose for dynamic conformal arc radiation therapy (DCAT). The EPID cine acquisition mode, that allows a frame acquisition rate of one image every 1.66 s, was studied with a monitor unit rate equal to 100 UM/min. In these conditions good signal stability, {+-}1% (2SD) evaluated during three months, signal reproducibility within {+-}0.8% (2SD) and linearity with dose and dose rate within {+-}1% (2SD) were obtained. The transit signal, S{sub t}, (due to the transmitted beam below the phantom) measured by the EPID cine acquisition mode was used to determine, (i) a set of correlation functions, F(w,L), defined as the ratio between S{sub t} and the dose at half thickness, D{sub m}, measured in solid water phantoms of different thicknesses, w and with square fields of side L, (ii) a set of factors, f(d,L), that take into account the different X-ray scatter contribution from the phantom to the S{sub t} signal as a function of the variation, d, of the air gap between the phantom and the EPID. The reconstruction of the isocenter dose, D{sub iso}, for DCAT was obtained convolving the transit signal values, obtained at different gantry angles, with the respective reconstruction factors determined by a house-made software. The method was tested with cylindrical and anthropomorphic phantoms and the results show that the reconstructed D{sub iso} values can be obtained with an accuracy within {+-}2.5% in cylindrical phantom and within {+-}3.4% for anthropomorphic phantom. In conclusion, the transit dosimetry by EPID was assessed to be adequate to perform DCAT in vivo dosimetry, that is not realizable with the other traditional techniques. Moreover, the method proposed here could be implemented to supply in vivo dose values in real time.

  15. Digital cine-imaging

    International Nuclear Information System (INIS)

    Masuda, Kazuhiro

    1992-01-01

    Digitization of fluoroscopic images has been developed for the digital cine imaging system as a result of the computer technology, television technology, and popularization of interventional radiology. Present digital cine imaging system is able to offer images similar to cine film because of the higher operatability and better image quality with the development of interventional radiology. As a result, its higher usefulness for catheter diagnosis examination except for interventional radiology was reported, and the possibility of having filmless cine is close to becoming a reality. However several problems have been pointed out, such as spatial resolution, time resolution, storage and exchangeability of data, disconsolidated viewing functions, etc. Anyhow, digital cine imaging system has some unresolved points and lots the needs to be discussed. The tendency of digitization is the passage of the time and we have to promote a study for more useful digital cine imaging system in team medical treatment which centers on the patients. (author)

  16. Craniocaudal Safety Margin Calculation Based on Interfractional Changes in Tumor Motion in Lung SBRT Assessed With an EPID in Cine Mode

    International Nuclear Information System (INIS)

    Ueda, Yoshihiro; Miyazaki, Masayoshi; Nishiyama, Kinji; Suzuki, Osamu; Tsujii, Katsutomo; Miyagi, Ken

    2012-01-01

    Purpose: To evaluate setup error and interfractional changes in tumor motion magnitude using an electric portal imaging device in cine mode (EPID cine) during the course of stereotactic body radiation therapy (SBRT) for non–small-cell lung cancer (NSCLC) and to calculate margins to compensate for these variations. Materials and Methods: Subjects were 28 patients with Stage I NSCLC who underwent SBRT. Respiratory-correlated four-dimensional computed tomography (4D-CT) at simulation was binned into 10 respiratory phases, which provided average intensity projection CT data sets (AIP). On 4D-CT, peak-to-peak motion of the tumor (M-4DCT) in the craniocaudal direction was assessed and the tumor center (mean tumor position [MTP]) of the AIP (MTP-4DCT) was determined. At treatment, the tumor on cone beam CT was registered to that on AIP for patient setup. During three sessions of irradiation, peak-to-peak motion of the tumor (M-cine) and the mean tumor position (MTP-cine) were obtained using EPID cine and in-house software. Based on changes in tumor motion magnitude (∆M) and patient setup error (∆MTP), defined as differences between M-4DCT and M-cine and between MTP-4DCT and MTP-cine, a margin to compensate for these variations was calculated with Stroom’s formula. Results: The means (±standard deviation: SD) of M-4DCT and M-cine were 3.1 (±3.4) and 4.0 (±3.6) mm, respectively. The means (±SD) of ∆M and ∆MTP were 0.9 (±1.3) and 0.2 (±2.4) mm, respectively. Internal target volume-planning target volume (ITV-PTV) margins to compensate for ∆M, ∆MTP, and both combined were 3.7, 5.2, and 6.4 mm, respectively. Conclusion: EPID cine is a useful modality for assessing interfractional variations of tumor motion. The ITV-PTV margins to compensate for these variations can be calculated.

  17. Evaluation of motion measurement using cine MRI for image guided stereotactic body radiotherapy on a new phantom platform

    Science.gov (United States)

    Cai, Jing; Wang, Ziheng; Yin, Fang-Fang

    2011-01-01

    The objective of this study is to investigate accuracy of motion tracking of cine magnetic resonance imaging (MRI) for image-guided stereotactic body radiotherapy. A phantom platform was developed in this work to fulfill the goal. The motion phantom consisted of a platform, a solid thread, a motor and a control system that can simulate motion in various modes. To validate its reproducibility, the phantom platform was setup three times and imaged with fluoroscopy using an electronic portal imaging device (EPID) for the same motion profile. After the validation test, the phantom platform was evaluated using cine MRI at 2.5 frames/second on a 1.5T GE scanner using five different artificial profiles and five patient profiles. The above profiles were again measured with EPID fluoroscopy and used as references. Discrepancies between measured profiles from cine MRI and EPID were quantified using root-mean-square (RMS) and standard deviation (SD). Pearson’s product moment correlational analysis was used to test correlation. The standard deviation for the reproducibility test was 0.28 mm. The discrepancies (RMS) between all profiles measured by cine MRI and EPID fluoroscopy ranged from 0.30 to 0.49 mm for artificial profiles and ranged from 0.75 to 0.91 mm for five patient profiles. The cine MRI sequence could precisely track phantom motion and the proposed motion phantom was feasible to evaluate cine MRI accuracy. PMID:29296304

  18. Cine MR imaging of valvular heart disease

    International Nuclear Information System (INIS)

    Underwood, S.R.; Firmin, D.N.; Mohiaddin, R.H.; Klipstein, R.H.; Bogren, H.G.; Rees, R.S.O.; Longmore, D.B.

    1987-01-01

    Cine MR imaging shows details of cardiac valve motion and the turbulence caused by regurgitation and stenosis. In 30 patients, the area of turbulence proximal to regurgitant valves correlated well with the regurgitant fraction measured from right and left ventricular stroke volumes. Turbulence distal to stenotic valves did not correlate with the pressure gradient because abnormal valves that were not stenosed produced turbulence. Valve motion and the presence of thrombus were easier to assess than in conventional images. Cine MR imaging provides an important addition to conventional imaging in valvular regurgitation, but pressure gradients cannot be assessed in valvular stenosis

  19. Assessment of voluntary deep inspiration breath-hold with CINE imaging for breast radiotherapy.

    Science.gov (United States)

    Estoesta, Reuben Patrick; Attwood, Lani; Naehrig, Diana; Claridge-Mackonis, Elizabeth; Odgers, David; Martin, Darren; Pham, Melissa; Toohey, Joanne; Carroll, Susan

    2017-10-01

    Deep Inspiration Breath-Hold (DIBH) techniques for breast cancer radiation therapy (RT) have reduced cardiac dose compared to Free Breathing (FB). Recently, a voluntary deep inspiration breath-hold (vDIBH) technique was established using in-room lasers and skin tattoos to monitor breath-hold. An in-house quality assessment of positional reproducibility during RT delivery with vDIBH in patients with left-sided breast cancer was evaluated. The electronic portal imaging device (EPID) was used in cinematographic (CINE) mode to capture a sequence of images during beam delivery. Weekly CINE images were retrospectively assessed for 20 left-sided breast cancer patients receiving RT in vDIBH, and compared with CINE images of 20 patients treated in FB. The intra-beam motion was assessed and the distance from the beam central axis (CA) to the internal chest wall (ICW) was measured on each CINE image. These were then compared to the planned distance on digitally reconstructed radiograph (DRR). The maximum intra-beam motion for any one patient measurement was 0.30 cm for vDIBH and 0.20 cm for FB. The mean difference between the distance from the CA to ICW on DRR and the equivalent distance on CINE imaging (as treated) was 0.28 cm (SD 0.17) for vDIBH patients and 0.25 cm (SD 0.14) for FB patients (P = 0.458). The measured values were comparable for patients undergoing RT in vDIBH, and for those in FB. This quality assessment showed that using in-room lasers and skin tattoos to independently monitor breath-hold in vDIBH as detected by 'on-treatment' CINE imaging is safe and effective. © 2017 The Royal Australian and New Zealand College of Radiologists.

  20. Portal dose measurement in radiotherapy using an electronic portal imaging device (EPID)

    International Nuclear Information System (INIS)

    Heijmen, B.J.M.; Pasma, K.L.; Kroonwijk, M.; Boer, J.C.J. de; Visser, A.G.; Huizenga, H.; Althof, V.G.M.

    1995-01-01

    Physical characteristics of a commercially available electronic portal imaging device (EPID), relevant to dosimetric applications in high-energy photon beams, have been investigated. The EPID basically consists of a fluorescent screen, mirrors and a CCD camera. Image acquisition for portal dose measurement has been performed with a special procedure, written in the command language that comes with the system. The observed day-to-day variation in local EPID responses, i.e. measured grey scale value (EPID signal) per unit of delivered portal dose, is 0.4% (1 SD); day-to-day variations in relative EPID responses (e.g. normalized to the on-axis response) are within 0.2% (1 SD). Measured grey scale values are linearly proportional to transmitted portal doses with a proportionality constant which is independent of the thickness of a flat, water-equivalent absorber in the beam, but which does significantly depend on the size of the applied X-ray beam. It is shown that the observed increase in EPID response with increasing field size is mainly due to contributions to the EPID signals from scattered light: visible photons produced by the X-ray beam in a point of the fluorescent screen not only generate a grey scale value in the corresponding point of the EPID image, but also lead (due to scatter from components of the EPID structure onto the CCD chip) to an increased grey scale value at all other points of the image. (Author)

  1. Cine MR imaging of internal derangements of the knee

    International Nuclear Information System (INIS)

    Niitsu, M.; Anno, I.; Ishikawa, N.; Akisada, M.; Fukubayashi, T.

    1990-01-01

    This paper assesses internal derangements of the knee joint by a new method of cine MR imaging. Cine MR imaging, involving cine acquisition of kinematic sagittal images during knee movement, was used to evaluate 51 symptomatic patients and 19 healthy subjects. Cine MR images of cruciate ligament fears showed disappearance of low-intensity bundles during knee movement, periodic appearance of joint fluid in the area of the ligament, and irregular tibial movement. Cine MR images of meniscal tears showed independent movement of meniscal fragments and periodic tear opening and closing. Twenty-seven of the 28 anterior cruciate ligament (ACL) tears confirmed arthroscopically were correctly identified with cine MR imaging, with a sensitivity of 96% and a specificity of 92%

  2. Cine MR imaging of the cardiovascular system

    International Nuclear Information System (INIS)

    Nishimura, Fumiaki; Yoshino, Yasushi; Mihara, Junji; Ichikawa, Seiichi; Kimura, Masahiko; Yano, Masao; Umeda, Masahiro; Oouchi, Toshihiro

    1990-01-01

    In recent years cine magnetic resonance imaging (MRI) has developed as a high-speed imaging technique that provides a high intensity signal even at a short repetition time (20-30 msec) by using an excited pulse with a small flip angle according to the gradient echo method, enabling about 20 to 30 continuous images of the same section per one cardiac cycle to be taken. On cine display of these continuous images, information concerning blood flow shown by a high intensity signal in comparison with that of the myocardium and vascular wall is obtained with high temporal resolution along with anatomical information. The present study reports the clinical usefulness of cine MRI in today's situation, inculding the following: calculation of the left ventricular ejection fraction and pulmonary-to-systemic flow ratio in congenital shunt disease by integration of the area of multisections through application of Simpson's method; diagnosis of the severity of valvular regurgitation, evaluation of stenosal diseases, and diagnosis of inflow from the fissured entry of dissecting aortic aneurysm by evaluating of an area of low intensity signal, probably based on the high velocity or turbulent blood flow: and evaluation of patency of the internal mammary artery bypass graft of the basis of the possible visualization of even thin blood vessels because of the high intensity signal of blood flow. In particular, the characteristics of this procedures are described by comparing it with other technologies in the field of diseases of valvular regurgitation. (author)

  3. Cine-MR imaging of the shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Allmann, K.H.; Uhl, M.; Gufler, H.; Kotter, E.; Langer, M. [Univ. Hospital, Freiburg (Germany). Dept. of Diagnostic Radiology; Biebow, N.; Hauer, M.P.; Reichelt, A. [Univ. Hospital, Freiburg (Germany). Dept. of Orthopedic Surgery

    1997-11-01

    Purpose: Shoulder lesions are usually examined with the joint in only one or two positions. We examined the shoulder with the joint in a variety of positions. We also assessed the application of cine-MR to the detection of instability and impingement. Material and Methods: The cine-MR examinations were performed in 30 patients and 15 healthy volunteers. We used an open 0.2 T system and a closed 1.0 T system. Spoiled gradient echo 2D T1-weighted images and turbo spin-echo T1- and T2-weighted images were obtained with a field of view of 180 mm. The examinations were videotaped and evaluated later. Results: Normal variations of the glenohumeral joint were easy to recognize. Subluxations and luxations of the humeral head as well as rupture of the labrum were identified. It was also possible to identify the labrum with a signal change after arthroscopic refixation. And we were able to objectively assess distances between the osseous structures during dynamic movement. Conclusion: Unlike static MR, cine-MR would appear to be useful in visualizing the capsular ligament complex of the gleno-humeral joint in impingement and instability. It also provides information on dynamic changes and may thus prove to be an important tool for shoulder diagnostics. The method may provide an early diagnosis in the subacromial impingement syndrome. (orig.).

  4. Cine-MR imaging of the shoulder

    International Nuclear Information System (INIS)

    Allmann, K.H.; Uhl, M.; Gufler, H.; Kotter, E.; Langer, M.; Biebow, N.; Hauer, M.P.; Reichelt, A.

    1997-01-01

    Purpose: Shoulder lesions are usually examined with the joint in only one or two positions. We examined the shoulder with the joint in a variety of positions. We also assessed the application of cine-MR to the detection of instability and impingement. Material and Methods: The cine-MR examinations were performed in 30 patients and 15 healthy volunteers. We used an open 0.2 T system and a closed 1.0 T system. Spoiled gradient echo 2D T1-weighted images and turbo spin-echo T1- and T2-weighted images were obtained with a field of view of 180 mm. The examinations were videotaped and evaluated later. Results: Normal variations of the glenohumeral joint were easy to recognize. Subluxations and luxations of the humeral head as well as rupture of the labrum were identified. It was also possible to identify the labrum with a signal change after arthroscopic refixation. And we were able to objectively assess distances between the osseous structures during dynamic movement. Conclusion: Unlike static MR, cine-MR would appear to be useful in visualizing the capsular ligament complex of the gleno-humeral joint in impingement and instability. It also provides information on dynamic changes and may thus prove to be an important tool for shoulder diagnostics. The method may provide an early diagnosis in the subacromial impingement syndrome. (orig.)

  5. Automatic segmentation and disease classification using cardiac cine MR images

    NARCIS (Netherlands)

    Wolterink, Jelmer M.; Leiner, Tim; Viergever, Max A.; Išgum, Ivana

    2018-01-01

    Segmentation of the heart in cardiac cine MR is clinically used to quantify cardiac function. We propose a fully automatic method for segmentation and disease classification using cardiac cine MR images. A convolutional neural network (CNN) was designed to simultaneously segment the left ventricle

  6. Development of a daily dosimetric control for radiation therapy using an electronic portal imaging device (EPID)

    International Nuclear Information System (INIS)

    Saboori, Mohammadsaeed

    2015-01-01

    Electronic Portal Imaging Devices (EPIDs) can be used to perform dose measurements during radiation therapy treatments if dedicated calibration and correction procedures are applied. The purpose of this study was to provide a new calibration and correction model for an amorphous silicon (a-Si) EPID for use in transit dose verification of step-and-shoot intensity modulated radiation therapy (IMRT). A model was created in a commercial treatment planning system to calculate the nominal two-dimensional (2D) dose map of each radiation field at the EPID level. The EPID system was calibrated and correction factors were determined using a reference set-up, which consisted a patient phantom and an EPID phantom. The advantage of this method is that for the calibration, the actual beam spectrum is used to mimic a patient measurement. As proof-of-principle, the method was tested for the verification of two 7-field IMRT treatment plans with tumor sites in the head-and-neck and pelvic region. Predicted and measured EPID responses were successfully compared to the nominal data from treatment planning using dose difference maps and gamma analyses. Based on our result it can be concluded that this new method of 2D EPID dosimetry is a potential tool for simple patient treatment fraction dose verification.

  7. Super-resolution imaging in a multiple layer EPID.

    Science.gov (United States)

    Chen, Haijian; Rottmann, Joerg; Yip, Stephen Sf; Morf, Daniel; Füglistaller, Rony; Star-Lack, Josh; Zentai, George; Berbeco, Ross

    2017-04-01

    A new portal imager consisting of four vertically stacked conventional electronic portal imaging device (EPID) layers has been constructed in pursuit of improved detective quantum efficiency (DQE). We hypothesize that super-resolution (SR) imaging can also be achieved in such a system by shifting each layer laterally by half a pixel relative to the layer above. Super-resolution imaging will improve resolution and contrast-to-noise ratio (CNR) in megavoltage (MV) planar and cone beam computed tomography (MV-CBCT) applications. Simulations are carried out to test this hypothesis with digital phantoms. To assess planar resolution, 2 mm long iron rods with 0.3 × 0.3 mm 2 square cross-section are arranged in a grid pattern at the center of a 1 cm thick solid water. For measuring CNR in MV-CBCT, a 20 cm diameter digital phantom with 8 inserts of different electron densities is used. For measuring resolution in MV-CBCT, a digital phantom featuring a bar pattern similar to the Gammex™ phantom is used. A 6 MV beam is attenuated through each phantom and detected by each of the four detector layers. Fill factor of the detector is explicitly considered. Projections are blurred with an estimated point spread function (PSF) before super-resolution reconstruction. When projections from multiple shifted layers are used in SR reconstruction, even a simple shift-add fusion can significantly improve the resolution in reconstructed images. In the reconstructed planar image, the grid pattern becomes visually clearer. In MV-CBCT, combining projections from multiple layers results in increased CNR and resolution. The inclusion of two, three and four layers increases CNR by 40%, 70% and 99%, respectively. Shifting adjacent layers by half a pixel almost doubles resolution. In comparison, using four perfectly aligned layers does not improve resolution relative to a single layer.

  8. SU-C-202-07: Protocol and Hardware for Improved Flood Field Calibration of TrueBeam FFF Cine Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, J; Faught, A; Yin, F [Duke University Medical Center, Durham, NC (United States)

    2016-06-15

    Purpose: Flattening filter free photon energies are commonly used for high dose treatments such as SBRT, where localization accuracy is essential. Often, MV cine imaging may be employed to verify correct localization. TrueBeam Electronic Portal Imaging Devices (EPIDs) equipped with the 40×30cm{sup 2} Image Detection Unit (IDU) are prone to image saturation at the image center especially for higher dose rates. While saturation often does not occur for cine imaging during treatment because the beam is attenuated by the patient, the flood field calibration is affected when the standard calibration procedure is followed. Here we describe the hardware and protocol to achieve improved image quality for this model of TrueBeam EPID. Methods: A stainless steel filter of uniform thickness was designed to have sufficient attenuation to avoid panel saturation for both 6XFFF and 10XFFF at the maximum dose rates (1400 MU/min & 2400 MU/min, respectively). The cine imaging flood field calibration was then acquired with the filter in place for the FFF energies under the standard calibration geometry (SDD=150cm). Image quality during MV cine was assessed with & without the modified flood field calibration using a low contrast resolution phantom and an anthropomorphic phantom. Results: When the flood field is acquired using the standard procedure (no filter in place), a pixel gain artifact is clearly present in the image center (r=3cm for 10XFFF at 2400 MU/min) which appears similar to and may be mis-attributed to panel saturation in the subject image. The artifact obscured all low contrast inserts at the image center and was also visible on the anthropomorphic phantom. Using the filter for flood field calibration eliminated the artifact. Conclusion: Use of a modified flood field calibration procedure improves image quality for cine MV imaging with TrueBeams equipped with the 40×30cm{sup 2} IDU.

  9. Quantifying the performance of two different types of commercial software programs for 3D patient dose reconstruction for prostate cancer patients: Machine log files vs. machine log files with EPID images.

    Science.gov (United States)

    Kadoya, Noriyuki; Kon, Yoshio; Takayama, Yoshiki; Matsumoto, Takuya; Hayashi, Naoki; Katsuta, Yoshiyuki; Ito, Kengo; Chiba, Takahito; Dobashi, Suguru; Takeda, Ken; Jingu, Keiichi

    2018-01-01

    We clarified the reconstructed 3D dose difference between two different commercial software programs (Mobius3D v2.0 and PerFRACTION v1.6.4). Five prostate cancer patients treated with IMRT (74 Gy/37 Fr) were studied. Log files and cine EPID images were acquired for each fraction. 3D patient dose was reconstructed using log files (Mobius3D) or log files with EPID imaging (PerFRACTION). The treatment planning dose was re-calculated on homogeneous and heterogeneous phantoms, and log files and cine EPID images were acquired. Measured doses were compared with the reconstructed point doses in the phantom. Next, we compared dosimetric metrics (mean dose for PTV, rectum, and bladder) calculated by Mobius3D and PerFRACTION for all fractions from five patients. Dose difference at isocenter between measurement and reconstructed dose for two software programs was within 3.0% in both homogeneous and heterogeneous phantoms. Moreover, the dose difference was larger using skip arc plan than that using full arc plan, especially for PerFRACTION (e.g., dose difference at isocenter for PerFRACTION: 0.34% for full arc plan vs. -4.50% for skip arc plan in patient 1). For patients, differences in dosimetric parameters were within 1% for almost all fractions. PerFRACTION had wider range of dose difference between first fraction and the other fractions than Mobius3D (e.g., maximum difference: 0.50% for Mobius3D vs. 1.85% for PerFRACTION), possibly because EPID may detect some types of MLC positioning errors such as miscalibration errors or mechanical backlash which cannot be detected by log files, or that EPID data might include image acquisition failure and image noise. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  10. Four-dimensional dose reconstruction through in vivo phase matching of cine images of electronic portal imaging device.

    Science.gov (United States)

    Yoon, Jihyung; Jung, Jae Won; Kim, Jong Oh; Yi, Byong Yong; Yeo, Inhwan

    2016-07-01

    A method is proposed to reconstruct a four-dimensional (4D) dose distribution using phase matching of measured cine images to precalculated images of electronic portal imaging device (EPID). (1) A phantom, designed to simulate a tumor in lung (a polystyrene block with a 3 cm diameter embedded in cork), was placed on a sinusoidally moving platform with an amplitude of 1 cm and a period of 4 s. Ten-phase 4D computed tomography (CT) images of the phantom were acquired. A planning target volume (PTV) was created by adding a margin of 1 cm around the internal target volume of the tumor. (2) Three beams were designed, which included a static beam, a theoretical dynamic beam, and a planning-optimized dynamic beam (PODB). While the theoretical beam was made by manually programming a simplistic sliding leaf motion, the planning-optimized beam was obtained from treatment planning. From the three beams, three-dimensional (3D) doses on the phantom were calculated; 4D dose was calculated by means of the ten phase images (integrated over phases afterward); serving as "reference" images, phase-specific EPID dose images under the lung phantom were also calculated for each of the ten phases. (3) Cine EPID images were acquired while the beams were irradiated to the moving phantom. (4) Each cine image was phase-matched to a phase-specific CT image at which common irradiation occurred by intercomparing the cine image with the reference images. (5) Each cine image was used to reconstruct dose in the phase-matched CT image, and the reconstructed doses were summed over all phases. (6) The summation was compared with forwardly calculated 4D and 3D dose distributions. Accounting for realistic situations, intratreatment breathing irregularity was simulated by assuming an amplitude of 0.5 cm for the phantom during a portion of breathing trace in which the phase matching could not be performed. Intertreatment breathing irregularity between the time of treatment and the time of planning CT was

  11. TU-E-BRA-02: A Method to Remove Support Arm Backscatter from EPID Images.

    Science.gov (United States)

    King, B; Greer, P

    2012-06-01

    To develop a method for removing the effect of support arm backscatter from Varian electronic portal imaging devices (EPIDs), improving the dosimetric abilities of the imager. A physical, kernel based model of the backscatter signal produced during an exposure was developed. The model parameters were determined through an optimization process, comparing measured images without arm backscatter (EPID removed from arm) to measured images that include arm backscatter. The backscatter model was used to develop a backscatter correction process that removes the support arm backscatter from measured EPID images. The correction process was tested by applying the method to measured images of 17 rectangular asymmetric fields and comparing the Result to off-arm images. The same process was repeated with 42 IMRT fields. The backscatter removal process was able to effectively remove the arm backscatter from all of the measured images and accurately predict the measured off-arm images. Comparing the corrected images to the measured off-arm images, the mean absolute difference at the centre of each rectangular field was 0.29% (standard deviation 0.18%). This is an improvement over the uncorrected images which gave a mean difference of 1.01% (standard deviation 0.73%). The largest discrepancy observed with the corrected images was 0.6%, compared to 2.8% for the uncorrected images. Comparing the corrected IMRT images to the measured off-arm images, an overall mean gamma value of 0.28 (standard deviation 0.04) was found using 2%, 2mm criteria. Comparison of the uncorrected images to the measured off-arm images resulted in an overall mean gamma of 0.40 (standard deviation 0.10). A method for accurately and reliably removing the effect of support arm backscatter from EPID images has been developed and extensively tested. The method can be applied to any measured EPID image and does not require any additional information about the exposure. © 2012 American Association of Physicists in

  12. Evaluation of aortic regurgitation using cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Tamai, Takuya; Konishi, Tokuji; Okamoto, Shinya; Sakuma, Hajime; Takeda, Kan; Nakano, Takeshi

    1993-01-01

    Cine magnetic resonance imaging (MRI) was used to assess aortic regurgitation (AR) in 13 patients with valvular disease and 3 normal subjects, and the results were compared to color Doppler flow mapping findings. AR produced a signal void in the left ventricle during the diastolic phase in all patients by MRI. There were no false positive or negative results compared with echocardiographic findings. Visual grading of cine MRI gave results similar to color flow Doppler echocardiography (88%). The distance and the area of aortic regurgitation using MRI correlated well with color Doppler flow mapping (r=0.82 and 0.88). However, measurements of distance and area by color flow Doppler tended to be larger than those by cine MRI. With current techniques echocardiography may overestimate the severity of AR as compared with cine MRI. In addition, MRI gives clinically useful information in patients in whom transthoracic Doppler echocardiography is not adequate. (author)

  13. Technical Note: Measurement of common carotid artery lumen dynamics using black-blood MR cine imaging.

    Science.gov (United States)

    Dai, Erpeng; Dong, Li; Zhang, Zhe; Li, Lyu; Zhang, Hui; Zhao, Xihai; Wang, Jinnan; Yuan, Chun; Guo, Hua

    2017-03-01

    To demonstrate the feasibility of measuring the common carotid artery (CCA) lumen dynamics using a black-blood cine (BB-cine) imaging method. Motion-sensitized driven-equilibrium (MSDE) prepared spoiled gradient sequence was used for the BB-cine imaging. CCAs of eleven healthy volunteers were studied using this method. Lumen dynamics, including lumen area evolution waveforms and distension values, were measured and evaluated by comparing this method with bright-blood cine (BrB-cine) imaging. Compared with the BrB-cine images, flow artifacts were effectively suppressed in the BB-cine images. BrB-cine images generally show larger lumen areas than BB-cine images. The lumen area waveforms and distension measurements from BB-cine imaging showed smaller variances among different subjects than BrB-cine imaging. The proposed BB-cine imaging technique can suppress the flow artifacts effectively and reduce the partial volume effects from the vessel wall. This might allow more accurate lumen dynamics measurements than traditional BrB-cine imaging, which may further be valuable for investigating biomechanical and functional properties of the cardiovascular system. © 2017 American Association of Physicists in Medicine.

  14. Intracardiac flow patterns studied by cine MR flow imaging

    International Nuclear Information System (INIS)

    Underwood, S.R.; Firmin, D.N.; Klipstein, R.H.; Rees, R.S.O.; Longmore, D.B.

    1986-01-01

    Velocity mapping by means of cine-MR imaging allows accurate measurement of velocity and flow within the cardiovascular system. A cine display and color coding simplify interpretation. The author have used the technique in a variety of patients to illustrate its potential. Velocity mapping in coronary artery by pass grafts in six patients provided a measure of graft function. Coronary artery velocities were measured in three subjects. Flow was measured through defects in the atrial septum, the ventricular septum, and a Gerbode defect. Velocity was reduced distal to coarctation of the aorta and was increased at the level of a partial venous occlusion by thrombosis. In a patient with isomerism, velocity mapping in the central vessels aided interpretation. Cine-MR imaging velocity mapping combined with conventional imaging yields important functional information on the cardiovascular system

  15. Dobutamine cine magnetic resonance imaging after myocardial infarction

    International Nuclear Information System (INIS)

    Giovagnoni, A.; Ligabue, G.; Romagnoli, R.; Reggio Emilia Univ., Reggio Emilia; Rossi, R.; Muia, N.; Modena, M.G.; Reggio Emilia Univ.

    1999-01-01

    Dobutamine Cine MRI is a new diagnostic imaging technique in the pretreatment (revascularization) assessment of myocardial infarction patients. In this issue are reported the result of a comparative study of the diagnostic yield of dobutamine Cine MRI with that of stress echocardiography in the assessment of viable myocardium. A new method for analysis of Cine MR images, employing digital subtraction, aimed at decreasing subjectivity in the quantitative assessment of myocardial wall thickening. Twenty-six patients (21 men and 5 women) with a history of myocardial infarction who were scheduled for revascularization were submitted to stress echocardiography and dobutamine Cine MRI to evaluate contractile recovery of the segments considered akinetic or hypo kinetic at baseline echocardiography. Dobutamine was administered in growing doses (5, 10, 15γ/kg/min). 16 segments of the left ventricle in each patient were considered. In the 416 segments studied, it was found that 307 normo kinetic, 64 scarred and 45 viable segments with stress echocardiography, versus 302 normo kinetic, 83 scarred and 31 viable segments with dobutamine MRI. Three months after revascularization 15 patients were examined to check contractile recovery of the segments considered as viable. Echocardiography had 79% sensitivity and 97% specificity, while Cine MRI had 96% and 86%, respectively. In patients with anteroseptal wall myocardial infarction stress echocardiography had 75% sensitivity and 97% specificity. Echocardiography permits to distinguish viable myocardium and scarred myocardial tissue with good sensitivity and specificity, but Cine MRI performs better. Cine MRI has much higher sensitivity than stress echocardiography and thus makes the technique of choice to evaluate viable myocardium in these sites. The digital subtraction technique is as accurate as manual measurements, but reduces the error rate and permits quicker evaluation, particularly in subendocardial thickening [it

  16. Magnetic resonance (MR) cine imaging of the human heart

    International Nuclear Information System (INIS)

    Waterton, J.C.

    1985-01-01

    A novel approach has been developed for MR cine imaging of the human heart by a modified ECG-gated 2DFT method. A pulse sequence has been devised to minimise the effects of saturation which can be anticipated in sequences that require rapid pulsing. Five frames are produced at the same anatomical level at predetermined intervals during the cardiac cycle. The total time taken to achieve this data is 8 minutes. Additional frames can be interleaved by repeating the sequence with an ECG-gated delay. The anatomical sections, which can be in any orthogonal plane, are then displayed as a cine loop. Cine display in the coronal plane has been used to examine 10 volunteers and 12 patients. In addition to the morphological feature displayed in single slice ECG-gated imaging, areas of dyskinesia can be detected and subjective estimates have been made of left ventricular function. (author)

  17. Fundamental Tongue Motions for Trumpet Playing: A Study Using Cine Magnetic Resonance Imaging (Cine MRI).

    Science.gov (United States)

    Furuhashi, Hiroko; Chikui, Toru; Inadomi, Daisuke; Shiraishi, Tomoko; Yoshiura, Kazunori

    2017-12-01

    Though the motions of structures outside the mouth in trumpet performance have been reported, the dynamics of intraoral structures remain unelucidated. This study explored the tongue's movement in trumpet playing using cine magnetic resonance imaging (cine MRI) and demonstrated the effects of intraoral anatomical structures on changes in pitch and dynamics. Cine MRI was applied to 18 trumpet players, who were divided into two groups (7 beginner, 11 advanced) based on their ability to play a certain high note. They were instructed to play a custom-made MRI-compatible simulated trumpet. Pitch-change tasks and dynamics-change tasks were assigned. The positions of the anatomical points and intraoral areas were identified on outlined images, and the changes associated with each task were evaluated. A forward and upward projection of the tongue was observed in the production of higher pitches, and there were no significant differences in all areas. In louder dynamics, a backward and downward bending of the tongue occurred, the tongue area became smaller (pcine MRI that certain tongue movements were associated with each task. Tongue protrusion in the production of higher pitch and bending in louder dynamics can be rationalized using acoustics theory and the movements of anatomical structures. These findings seem to be consistent regardless of the player's proficiency.

  18. WE-DE-BRA-06: Evaluation of the Imaging Performance of a Novel Water-Equivalent EPID

    Energy Technology Data Exchange (ETDEWEB)

    Blake, SJ [School of Physics, The University of Sydney, Sydney, NSW (Australia); The Ingham Institute, Liverpool, NSW (Australia); Cheng, J; Atakaramians, S; Kuncic, Z [School of Physics, The University of Sydney, Sydney, NSW (Australia); Vial, P [School of Physics, The University of Sydney, Sydney, NSW (Australia); The Ingham Institute, Liverpool, NSW (Australia); Department of Medical Physics, Liverpool & Macarthur Cancer Therapy Centres, Liverpool, NSW (Australia); Lu, M [Perkin-Elmer Medical Imaging, Santa Clara, California (United States); Meikle, S [Faculty of Health Sciences and Brain and Mind Centre, The University of Sydney, Sydney, NSW (Australia)

    2016-06-15

    Purpose: To evaluate the megavoltage imaging performance of a novel, water-equivalent electronic portal imaging device (EPID) developed for simultaneous imaging and dosimetry applications in radiotherapy. Methods: A novel EPID prototype based on active matrix flat panel imager technology has been developed by our group and previously reported to exhibit a water-equivalent dose response. It was constructed by replacing all components above the photodiode detector in a standard clinical EPID (including the copper plate and phosphor screen) with a 15 × 15 cm{sup 2} array of plastic scintillator fibers. Individual fibers measured 0.5 × 0.5 × 30 mm{sup 3}. Spatial resolution was evaluated experimentally relative to that of a standard EPID with the thin slit technique to measure the modulation transfer function (MTF) for 6 MV x-ray beams. Monte Carlo (MC) EPID models were used to benchmark simulated MTFs against the measurements. The zero spatial frequency detective quantum efficiency (DQE(0)) was simulated for both EPID configurations and a preliminary optimization of the prototype was performed by evaluating DQE(0) as a function of fiber length up to 50 mm. Results: The MC-simulated DQE(0) for the prototype EPID configuration was ∼7 times greater than that of the standard EPID. The prototype’s DQE(0) also increased approximately linearly with fiber length, from ∼1% at 5 mm length to ∼11% at 50 mm length. The standard EPID MTF was greater than the prototype EPID’s for all spatial frequencies, reflecting the trade off between x-ray detection efficiency and spatial resolution with thick scintillators. Conclusion: This study offers promising evidence that a water-equivalent EPID previously demonstrated for radiotherapy dosimetry may also be used for radiotherapy imaging applications. Future studies on optimising the detector design will be performed to develop a next-generation prototype that offers improved megavoltage imaging performance, with the aim to at

  19. WE-DE-BRA-06: Evaluation of the Imaging Performance of a Novel Water-Equivalent EPID

    International Nuclear Information System (INIS)

    Blake, SJ; Cheng, J; Atakaramians, S; Kuncic, Z; Vial, P; Lu, M; Meikle, S

    2016-01-01

    Purpose: To evaluate the megavoltage imaging performance of a novel, water-equivalent electronic portal imaging device (EPID) developed for simultaneous imaging and dosimetry applications in radiotherapy. Methods: A novel EPID prototype based on active matrix flat panel imager technology has been developed by our group and previously reported to exhibit a water-equivalent dose response. It was constructed by replacing all components above the photodiode detector in a standard clinical EPID (including the copper plate and phosphor screen) with a 15 × 15 cm 2 array of plastic scintillator fibers. Individual fibers measured 0.5 × 0.5 × 30 mm 3 . Spatial resolution was evaluated experimentally relative to that of a standard EPID with the thin slit technique to measure the modulation transfer function (MTF) for 6 MV x-ray beams. Monte Carlo (MC) EPID models were used to benchmark simulated MTFs against the measurements. The zero spatial frequency detective quantum efficiency (DQE(0)) was simulated for both EPID configurations and a preliminary optimization of the prototype was performed by evaluating DQE(0) as a function of fiber length up to 50 mm. Results: The MC-simulated DQE(0) for the prototype EPID configuration was ∼7 times greater than that of the standard EPID. The prototype’s DQE(0) also increased approximately linearly with fiber length, from ∼1% at 5 mm length to ∼11% at 50 mm length. The standard EPID MTF was greater than the prototype EPID’s for all spatial frequencies, reflecting the trade off between x-ray detection efficiency and spatial resolution with thick scintillators. Conclusion: This study offers promising evidence that a water-equivalent EPID previously demonstrated for radiotherapy dosimetry may also be used for radiotherapy imaging applications. Future studies on optimising the detector design will be performed to develop a next-generation prototype that offers improved megavoltage imaging performance, with the aim to at least

  20. Image processing in cine-scintigraphy. Organization of the CINE 200 system

    International Nuclear Information System (INIS)

    Tournier, E.; Axelrad, C.; Monge, J.; Beccia, A.; Bouvier, A.

    1975-01-01

    The CINE 200 system, although using a small computer to reduce costs, is shown to be a highly efficient instrument for the processing of scintigraphic images. This was achieved by creating an acquisition and display system branched directly onto the memory, reducing the processing times by the writing of fast micro-programmes, and cutting down the place occupied by the programmes in the live memory by a good organization of these programmes. This internal organization of the system, the insertion and role of the programmes, the data organization and the working procedure are described briefly [fr

  1. TU-E-BRA-03: Real-Time Fiducial Detection and Prostate Movement Assessment with Cine MV Images in RapidArc Treatments.

    Science.gov (United States)

    Armendariz, J Azcona; Li, R; Mok, E; Xing, L

    2012-06-01

    To develop an algorithm for detection of metallic fiducial markers in cine MV images, and to assess the prostate movement during RapidArc treatment. A Varian TrueBeam linear accelerator (LINAC) was used to deliver RapidArc treatment for prostate patients. Cine images were acquired with the onboard electronic portal imaging device (EPID) using the MV therapeutic beam. Three metallic fiducial markers were implanted inside the prostate. To detect the fiducial position, we explicitly account for the possible marker blockage by MLC during beam modulation. If the marker is not blocked, we employ the planning coordinates of the marker centroids projected onto the cine MV images and perform template matching in the vicinity of its projection to localize the actual position of the marker. Displacements of the fiducial markers are assessed by comparing the actual and planned positions. We analyzed ∼280 cine MV images acquired during a 55-sec RapidArc treatment for a prostate patient. The three markers were visible in about 46%, 52%, and 48% of the images, and at least one fiducial was visible during almost entire treatment (97% of the time). The marker detection algorithm agrees well with manual detection (< 0.2 mm). The mean displacement for each fiducial was 0.40 ± 0.42, 0.27 ± 0.29, and 0.46 ± 0.34 mm. The maximum displacement was 2.33, 1.75, and 2.23 mm. An algorithm for automatic detection of fiducial markers in cine MV images has been developed. The prostate movement during a RapidArc treatment has been analyzed for a patient with implanted markers. Accurate target positioning is achieved at all times during treatment. In light of the random nature of intrafraction prostate motion, this work represents an important step toward real-time image-guided prostate radiation therapy. © 2012 American Association of Physicists in Medicine.

  2. Using an EPID for patient-specific VMAT quality assurance

    International Nuclear Information System (INIS)

    Bakhtiari, M.; Kumaraswamy, L.; Bailey, D. W.; Boer, S. de; Malhotra, H. K.; Podgorsak, M. B.

    2011-01-01

    Purpose: A patient-specific quality assurance (QA) method was developed to verify gantry-specific individual multileaf collimator (MLC) apertures (control points) in volumetric modulated arc therapy (VMAT) plans using an electronic portal imaging device (EPID). Methods: VMAT treatment plans were generated in an Eclipse treatment planning system (TPS). DICOM images from a Varian EPID (aS1000) acquired in continuous acquisition mode were used for pretreatment QA. Each cine image file contains the grayscale image of the MLC aperture related to its specific control point and the corresponding gantry angle information. The TPS MLC file of this RapidArc plan contains the leaf positions for all 177 control points (gantry angles). In-house software was developed that interpolates the measured images based on the gantry angle and overlays them with the MLC pattern for all control points. The 38% isointensity line was used to define the edge of the MLC leaves on the portal images. The software generates graphs and tables that provide analysis for the number of mismatched leaf positions for a chosen distance to agreement at each control point and the frequency in which each particular leaf mismatches for the entire arc. Results: Seven patients plans were analyzed using this method. The leaves with the highest mismatched rate were found to be treatment plan dependent. Conclusions: This in-house software can be used to automatically verify the MLC leaf positions for all control points of VMAT plans using cine images acquired by an EPID.

  3. Evaluation of aortic distensibility using cine MR imaging

    International Nuclear Information System (INIS)

    Takahashi, Masashi; Murata, Kiyoshi; Mori, Masayuki

    1992-01-01

    Regional aortic distensibility was measured noninvasively using cine MR imaging to determine whether it correlates with aging or risk of coronary artery disease (CAD). Twenty-two patients with CAD confirmed by angiography and 33 without CAD underwent cine MR imaging. Thirty-two sequential images were obtained in one cardiac cycle. The cross sectional area of the descending thoracic aorta was measured on both diastolic (A) and systolic (A') images. Aortic distensibility (A.D.) was calculated from the following equation: A.D.=(A'-A)/A/ΔP.(ΔP represents pulse pressure). Results of a simple regression analysis showed that decreased regional aortic distensibility was significantly correlated with the age of the patients (r=-0.762, p<0.005). In addition, the parameter was lower in patients with CAD than those without CAD (p<0.05). In conclusion, regional aortic distensibility derived from cine MR imaging is a useful parameter to evaluate not only aging but also pathological atherosclerosis of the aorta. In addition, this parameter might have some potential to evaluate the prediction of CAD in patients with normal serum cholesterol. (author)

  4. Two-dimensional sonographic cine imaging improves confidence in the initial evaluation of the fetal heart.

    Science.gov (United States)

    Poole, Patricia Sims; Chung, Romy; Lacoursiere, Yvette; Palmieri, Carolina Rossi; Hull, Andrew; Engelkemier, Dawn; Rochelle, Michele; Trivedi, Neha; Pretorius, Dolores H

    2013-06-01

    Initial screening sonography of the fetal heart with static images is often inadequate, resulting in repeated imaging or failure to detect abnormalities. We hypothesized that the addition of short cine clips would reduce the need for repeated imaging. Two-dimensional (2D) static sonograms and short 2D cine clips of the 4-chamber view and left and right ventricular outflow tracts were obtained from 342 patients with gestational ages of greater than 16 weeks. A diagnostic radiologist and a perinatologist retrospectively reviewed the static and cine images independently and graded them as normal, abnormal, or suboptimal. A statistically significant increase in the number of structures called normal was seen when 2D cine clips were added to static imaging for both observers (P cine images versus 61.9% with static images alone, whereas the perinatologist recorded 68.1% as normal versus 58.8%, respectively. The radiologist called 77.8% of structures normal with cine images only versus 61.9% with static images only (P cine images alone (38.9%) versus static images alone (58.8%). The use of cine loops alone resulted in no significant increase in the ability to clear the heart as normal. The maternal body mass index was inversely associated with the ability to clear structures when 2D cine images were added to static images (P cine clips to standard 2D static imaging of the fetal heart significantly improves the number of structures cleared as normal. Two-dimensional cine clips are easily obtained, add little time to a study, and require minimal archival space.

  5. Comparisons of images simultaneously documented by digital subtraction coronary arteriography and cine coronary arteriography

    International Nuclear Information System (INIS)

    Kimura, Koji; Takamiya, Makoto; Yamamoto, Kazuo; Ohta, Mitsushige; Naito, Hiroaki

    1988-01-01

    Using an angiography apparatus capable of simultaneously processing digital subtraction angiograms and cine angiograms, the diagnostic capabilities of both methods for the coronary arteries (DSCAG and Cine-CAG) were compared. Twenty stenotic lesions of the coronary arteries of 11 patients were evaluated using both modalities. The severity of stenosis using DSCAG with a 512x512x8 bit matrix was semiautomatically measured on the cathode ray tube (CRT) based on enlarged images on the screen of a Vanguard cine projector which were of the same size as those of or 10 times larger than images of Cine-CAG. The negative and positive hard copies of DSCAG images were also compared with those of Cine-CAG. The correlation coefficients of the severity of stenosis by DSCAG and Cine-CAG were as follows: (1) the same size DSCAG images on CRT to Cine-CAG, 0.95, (2) 10 times enlarged DSCAG images on CRT to Cine-CAG, 0.96, and (3) the same size DSCAG images on negative and positive hard copies to Cine-CAG, 0.97. The semiautomatically measured values of 10 times enlarged DSCAG images on CRT and the manually measured values of the same size negative and positive DSCAG images in hard copy closely correlated with the values measured using Cine-CAG. When the liver was superimposed in the long-axis projection, the diagnostic capabilities of DSCAG and Cine-CAG were compared. The materials included 10 left coronary arteriograms and 11 right coronary arteriograms. Diagnostically, DSCAG was more useful than Cine-CAG in the long-axis projection. (author)

  6. A Technique for Generating Volumetric Cine-Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

    2016-01-01

    Purpose: The purpose of this study was to develop a techique to generate on-board volumetric cine-magnetic resonance imaging (VC-MRI) using patient prior images, motion modeling, and on-board 2-dimensional cine MRI. Methods and Materials: One phase of a 4-dimensional MRI acquired during patient simulation is used as patient prior images. Three major respiratory deformation patterns of the patient are extracted from 4-dimensional MRI based on principal-component analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2-dimensional cine MRI. The method was evaluated using both digital extended-cardiac torso (XCAT) simulation of lung cancer patients and MRI data from 4 real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using volume-percent-difference (VPD), center-of-mass-shift (COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest (ROI) selection, patient breathing pattern change, and noise on the estimation accuracy were also evaluated. Results: Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between normalized profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was, on average, 8.43 ± 1.52% and the COMS was, on average, 0.93 ± 0.58 mm across all time steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against

  7. A Technique for Generating Volumetric Cine-Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Wendy [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Ren, Lei, E-mail: lei.ren@duke.edu [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Cai, Jing [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Zhang, You [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Chang, Zheng; Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

    2016-06-01

    Purpose: The purpose of this study was to develop a techique to generate on-board volumetric cine-magnetic resonance imaging (VC-MRI) using patient prior images, motion modeling, and on-board 2-dimensional cine MRI. Methods and Materials: One phase of a 4-dimensional MRI acquired during patient simulation is used as patient prior images. Three major respiratory deformation patterns of the patient are extracted from 4-dimensional MRI based on principal-component analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2-dimensional cine MRI. The method was evaluated using both digital extended-cardiac torso (XCAT) simulation of lung cancer patients and MRI data from 4 real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using volume-percent-difference (VPD), center-of-mass-shift (COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest (ROI) selection, patient breathing pattern change, and noise on the estimation accuracy were also evaluated. Results: Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between normalized profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was, on average, 8.43 ± 1.52% and the COMS was, on average, 0.93 ± 0.58 mm across all time steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against

  8. Single-breath-hold 3-D CINE imaging of the left ventricle using Cartesian sampling.

    Science.gov (United States)

    Wetzl, Jens; Schmidt, Michaela; Pontana, François; Longère, Benjamin; Lugauer, Felix; Maier, Andreas; Hornegger, Joachim; Forman, Christoph

    2018-02-01

    Our objectives were to evaluate a single-breath-hold approach for Cartesian 3-D CINE imaging of the left ventricle with a nearly isotropic resolution of [Formula: see text] and a breath-hold duration of [Formula: see text]19 s against a standard stack of 2-D CINE slices acquired in multiple breath-holds. Validation is performed with data sets from ten healthy volunteers. A Cartesian sampling pattern based on the spiral phyllotaxis and a compressed sensing reconstruction method are proposed to allow 3-D CINE imaging with high acceleration factors. The fully integrated reconstruction uses multiple graphics processing units to speed up the reconstruction. The 2-D CINE and 3-D CINE are compared based on ventricular function parameters, contrast-to-noise ratio and edge sharpness measurements. Visual comparisons of corresponding short-axis slices of 2-D and 3-D CINE show an excellent match, while 3-D CINE also allows reformatting to other orientations. Ventricular function parameters do not significantly differ from values based on 2-D CINE imaging. Reconstruction times are below 4 min. We demonstrate single-breath-hold 3-D CINE imaging in volunteers and three example patient cases, which features fast reconstruction and allows reformatting to arbitrary orientations.

  9. Prostate gland motion assessed with cine-magnetic resonance imaging (cine-MRI)

    International Nuclear Information System (INIS)

    Ghilezan, Michel J.; Jaffray, David A.; Siewerdsen, Jeffrey H.; Herk, Marcel van; Shetty, Anil; Sharpe, Michael B.; Zafar Jafri, Syed; Vicini, Frank A.; Matter, Richard C.; Brabbins, Donald S.; Martinez, Alvaro A.

    2005-01-01

    Purpose: To quantify prostate motion during a radiation therapy treatment using cine-magnetic resonance imaging (cine-MRI) for time frames comparable to that expected in an image-guided radiation therapy treatment session (20-30 min). Materials and Methods: Six patients undergoing radiation therapy for prostate cancer were imaged on 3 days, over the course of therapy (Weeks 1, 3, and 5). Four hundred images were acquired during the 1-h MRI session in 3 sagittal planes through the prostate at 6-s intervals. Eleven anatomic points of interest (POIs) have been used to characterize prostate/bony pelvis/abdominal wall displacement. Motion traces and standard deviation for each of the 11 POIs have been determined. The probability of displacement over time has also been calculated. Results: Patients were divided into 2 groups according to rectal filling status: full vs. empty rectum. The displacement of POIs (standard deviation) ranged from 0.98 to 1.72 mm for the full-rectum group and from 0.68 to 1.04 mm for the empty-rectum group. The low standard deviations in position (2 mm or less) would suggest that these excursions have a low frequency of occurrence. The most sensitive prostate POI to rectal wall motion was the midposterior with a standard deviation of 1.72 mm in the full-rectum group vs. 0.79 mm in the empty-rectum group (p 0.0001). This POI has a 10% probability of moving more than 3 mm in a time frame of ∼1 min if the rectum is full vs. ∼20 min if the rectum is empty. Conclusion: Motion of the prostate and seminal vesicles during a time frame similar to a standard treatment session is reduced compared to that reported in interfraction studies. The most significant predictor for intrafraction prostate motion is the status of rectal filling. A prostate displacement of <3 mm (90%) can be expected for the 20 min after the moment of initial imaging for patients with an empty rectum. This is not the case for patients presenting with full rectum. The determination

  10. Usefulness of true FISP cine MR imaging in patients with poor cardiac function

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, Toshiharu; Yamada, Naoaki; Motooka, Makoto; Enomoto, Naoyuki; Maeshima, Isamu; Matsuda, Kazuhide; Urayama, Shinichi; Ikeo, Miki [National Cardiovascular Center, Suita, Osaka (Japan)

    2002-01-01

    This study was done to assess the value of True FISP cine in patients with poor cardiac function. True FISP cine and FLASH cine imaging were performed on a 1.5 T machine. Both short axis and horizontal long axis imaging sections were used. The imaging sections used a Matrix (120 x 128), FOV (24 x 32 cm), and had a slice thickness of 8 mm. The imaging time for True FISP cine was 8 heart beats and 17 heart beats for FLASH cine. The contrast-to-noise ratio between the blood and myocardium (CNR) was measured at enddiastole and endsystole. The subjects in the study were 10 healty volunteers (average age 26.5{+-}3.2 years) and 12 patients with hypofunction (average age 53.9{+-}13.2 years). In the volunteers, the CNR of the short axis imaging was similar in both True FISP (24.6{+-}3.7) and FLASH (23.4{+-}5.9). In the patients with poor cardiac function however, the CNR of True FISP was larger than FLASH in both the short and long axis. In the short axis (22.7{+-}6.1 vs. 17.9{+-}5.3, P<0.01) and in the long axis (17.4{+-}4.3 vs. 9.3{+-}4.0, P<0.01). We conclude that True FISP cine has a higher contrast in a shorter imaging time than FLASH cine. True FISP cine is especially useful in patients with poor cardiac function. (author)

  11. A study of intraluminal flow in patients with aortic disease by cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Ohnishi, Shusaku; Fukui, Sugao; Kusuoka, Hideo; Kitabatake, Akira; Kamada, Takenobu.

    1990-01-01

    To evaluate the usefulness of cine magnetic resonance (MR) imaging in the diagnosis of aortic disease, we applied cine MR sequences with conventional spin echo (SE) sequence to 15 patients with aortic aneurysm and 5 patients with aortic dissection. ECG gated multi slice SE images (single echo) were obtained in transverse plane and the planes along the long axis of aorta. TE of SE sequence ranged from 15 to 32 msec. Cine MR images were obtained in 17 frames, where TR ranged from 30 to 60 msec and TE from 10 to 22 msec. We got these results as follows. For aortic aneurysm, SE images showed aneurysmal dilatation in thoracic aorta in 9 cases, and in abdominal aorta in 6 cases. Cine MR images showed us the intraluminal flow with high signal intensity. We could differentiate the slow flow image from mural thrombus using SE and cine MR sequences in the same plane. We could evaluate the dynamic flow image within a cavity of aneurysm and in in-flow and out-flow portions of aorta by cine MR imaging. For aortic dissection, SE images delineated the intimal tear and two separated lumens in all cases. We could obtain flow images within true and false lumen by cine MR imaging. The signal intensity within true lumen was higher than that within false lumen. It seemed to be due to the difference of flow velocity and the turbulence within false lumen. Entry to false lumen was seen as the interruption of dissected intima on SE images. Cine MR images clearly depicted the blood flow communication between two lumens through the entry. In 3 of 5 cases the blood flow through the entry was seen in both directions, from true to false lumen in systole and inversely in diastole. Thus, cine MR imaging will add the useful hemodynamic information in the diagnosis of aortic disease by conventional MR imaging. (author)

  12. Spirometer-controlled cine magnetic resonance imaging used to diagnose tracheobronchomalacia in paediatric patients.

    Science.gov (United States)

    Ciet, Pierluigi; Wielopolski, Piotr; Manniesing, Rashindra; Lever, Sandra; de Bruijne, Marleen; Morana, Giovanni; Muzzio, Pier Carlo; Lequin, Maarten H; Tiddens, Harm A W M

    2014-01-01

    Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard for diagnosing TBM; however it has major disadvantages, such as general anaesthesia. Cine computed tomography (CT) is a noninvasive alternative used to diagnose TBM, but its use in children is restricted by ionising radiation. Our aim was to evaluate the feasibility of spirometer-controlled cine magnetic resonance imaging (MRI) as an alternative to cine-CT in a retrospective study. 12 children with a mean age (range) of 12 years (7-17 years), suspected of having TBM, underwent cine-MRI. Static scans were acquired at end-inspiration and expiration covering the thorax using a three-dimensional spoiled gradient echo sequence. Three-dimensional dynamic scans were performed covering only the central airways. TBM was defined as a decrease of the trachea or bronchi diameter >50% at end-expiration in the static and dynamic scans. The success rate of the cine-MRI protocol was 92%. Cine-MRI was compared with bronchoscopy or chest CT in seven subjects. TBM was diagnosed by cine-MRI in seven (58%) out of 12 children and was confirmed by bronchoscopy or CT. In four patients, cine-MRI demonstrated tracheal narrowing that was not present in the static scans. Spirometer controlled cine-MRI is a promising technique to assess TBM in children and has the potential to replace bronchoscopy.

  13. Geometric control of the collimators with an image analysis program obtained by the EPID; Control geometrico del multilaminas con un programa de analisis de imagen obtenida con el EPID

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Enriquez, F.; Montejo Arteche, A.; Sanchez Mazon, J.; Vazquez Rodriguez, J. A.; Mendigueren Santiago, M. A.; Pacheco Baldor, M. T.; Raba Diez, J. I.

    2013-07-01

    To improve the traditional method of geometric adjustment of blades was a plugin from the Image J program that analyzes an image, acquired with the EPID accelerator, the way Stripe Test (test lines). The program was designed for an Elekta Accelerator model Precise, with slices of 1cm thick and a program of acquisition of images of the EPID Iview GT 3.4. At the end of the process it has resulted in the displacement, in millimeters, that needs to be done to adjust each of the blades. (Author)

  14. Cine-MR imaging of valvular heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hyung; Han, Man Chung; Kim, Chu Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Dae Jin; Kim, Woo Sung; Park, Hyun Wuk; Cho, Zang Hee [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    1989-04-15

    Cine-MR imaging was done in 2 normal persons and 9 patients of valvular heart disease with 2.0 T superconducting MR system (Spectro-2000; GoldStar, Korea). The MRI was undertaken using gradient echo technique with small flip angle. Repetition time (TR) was 34 msec, and echo time (TE), 18 msec. In most cases, 20 to 30 frames could be obtained during one cardiac cycle. With normal heart, high signal intensity was identified in the blood filled cardiac chambers. Transient signal void was observed near tricuspid, mitral and aortic valves due to the turbulences induced by valve opening or closure. In 6 cases of mitral valvular disease, mitral valve was identified in all cases. The valvular motion was limited revealing doming toward cardiac apex during diastole. Signal void was evident in pansystolic phase of left ventricle in all cases. Evidence of combined aortic or tricuspid valve disease were also demonstrated, revealing signal void in the corresponding cardiac chambers. Cine-MRI seemed to be not only a good non-invasive diagnostic modality for the valvular heart disease, but also an accurate modality for cardiac functional evaluation.

  15. The diagnostic value of cine-MR imaging in diseases of great vessels

    International Nuclear Information System (INIS)

    Sasaki, Shigeyuki; Yoshida, Hideaki; Matsui, Yoshiro; Sakuma, Makoto; Yasuda, Keihide; Tanabe, Tatsuzo; Chouji, H.

    1990-01-01

    The diagnostic value of cine magnetic resonance imaging (cine-MRI) was evaluated in 10 patients with diseases of great vessels. The parameters necessary to decide the appropriate treatment, such as presence and extension of intimal flap, DeBakey type classification, identification of the entry, differentiation between true and false lumen, and between thrombosis and slow flow were demonstrated in all patients with dissecting aortic aneurysm. However, abdominal aortic branches could not be demonstrated enough by cine-MRI, therefore conventional AOG was necessary to choose the operative procedure in these cases. In patients with thoracic aortic aneurysm (TAA), cine-MRI was valuable in demonstrating both blood flow and thrombus in the lumen of aneurysm, and AOG was thought to be unnecessary in most cases. Cine-MRI is a promising new technique for the evaluation of diseases of great vessels. (author)

  16. Cine-magnetic resonance imaging evaluation of communication between middle cranial fossa arachnoid cysts and cisterns

    International Nuclear Information System (INIS)

    Eguchi, Takahiko; Nikaido, Yuji; Shiomi, Kazuaki; Fujimoto, Takatoshi; Otsuka, Hiroyuki; Takeuchi, Hiroshi; Taoka, Toshiaki.

    1996-01-01

    Cine-magnetic resonance (MR) imaging examinations were performed in 10 patients with middle cranial fossa arachnoid cysts to evaluate communication between the cysts and the normal cerebrospinal fluid (CSF) space. Eight of 10 patients were evaluated by time of flight cine-MR imaging, and two by phase contrast cine-MR imaging. Two patients underwent membranectomy of the cysts, and were evaluated both pre-and postoperatively. Computed tomography cisternography was used to confirm communication between the cysts and the surrounding cisterns. Pulsatile fluid motion within the cysts was present in all patients. However, marked fluid motion and jet flow between the cysts and the surrounding cisterns were only observed in communicating cysts. In the two patients who underwent membranectomy, postoperative examination found greater fluid motion and jet flow not previously present. Cine-MR imaging demonstration of marked pulsatile fluid motion accompanied by jet flow suggests that a cyst communicates with the normal CSF space. (author)

  17. Cine magnetic resonance imaging for evaluation of cardiac structure and flow dynamics in congenital heart disease

    International Nuclear Information System (INIS)

    Akagi, Teiji; Kiyomatsu, Yumi; Ohara, Nobutoshi; Takagi, Junichi; Sato, Noboru; Kato, Hirohisa; Eto, Takaharu.

    1989-01-01

    Cine magnetic resonance imaging (Cine MRI) was performed in 20 patients aged 19 days to 13 years (mean 4.0 years), who had congenital heart disease confirmed at echocardiography or angiography. Prior to cine MRI, gated MRI was performed to evaluate for cardiac structure. Cine MRI was demonstrated by fast low fip angle shot imaging technique with a 30deg flip angle, 15 msec echo time, 30-40 msec pulse repetition time, and 128 x 128 acquisition matrix. Abnormalities of cardiac structure were extremely well defined in all patients by gated MRI. Intracardiac or intravascular blood flow were visualized in 17 (85%) of 20 patients by cine MRI. Left to right shunt flow through ventricular septal defect, atrial septal defect, and endocardial cushion defect were visualized with low signal intensity area. Low intensity jets flow through the site of re-coarctation of the aorta were also visualized. However, the good recording of cine MRI was not obtained because of artifacts in 3 of 20 patients (15%) who had severe congestive heart failure or respiratory arrhythmia. Gated MRI provides excellent visualization of fine structure, and cine MRI can provide high spatial resolution imaging of flow dynamic in a variety of congenital heart disease, noninvasively. (author)

  18. Markerless EPID image guided dynamic multi-leaf collimator tracking for lung tumors

    Science.gov (United States)

    Rottmann, J.; Keall, P.; Berbeco, R.

    2013-06-01

    Compensation of target motion during the delivery of radiotherapy has the potential to improve treatment accuracy, dose conformity and sparing of healthy tissue. We implement an online image guided therapy system based on soft tissue localization (STiL) of the target from electronic portal images and treatment aperture adaptation with a dynamic multi-leaf collimator (DMLC). The treatment aperture is moved synchronously and in real time with the tumor during the entire breathing cycle. The system is implemented and tested on a Varian TX clinical linear accelerator featuring an AS-1000 electronic portal imaging device (EPID) acquiring images at a frame rate of 12.86 Hz throughout the treatment. A position update cycle for the treatment aperture consists of four steps: in the first step at time t = t0 a frame is grabbed, in the second step the frame is processed with the STiL algorithm to get the tumor position at t = t0, in a third step the tumor position at t = ti + δt is predicted to overcome system latencies and in the fourth step, the DMLC control software calculates the required leaf motions and applies them at time t = ti + δt. The prediction model is trained before the start of the treatment with data representing the tumor motion. We analyze the system latency with a dynamic chest phantom (4D motion phantom, Washington University). We estimate the average planar position deviation between target and treatment aperture in a clinical setting by driving the phantom with several lung tumor trajectories (recorded from fiducial tracking during radiotherapy delivery to the lung). DMLC tracking for lung stereotactic body radiation therapy without fiducial markers was successfully demonstrated. The inherent system latency is found to be δt = (230 ± 11) ms for a MV portal image acquisition frame rate of 12.86 Hz. The root mean square deviation between tumor and aperture position is smaller than 1 mm. We demonstrate the feasibility of real-time markerless DMLC

  19. Cardiovascular cine imaging and flow evaluation using Fast Interrupted Steady-State (FISS) magnetic resonance.

    Science.gov (United States)

    Edelman, Robert R; Serhal, Ali; Pursnani, Amit; Pang, Jianing; Koktzoglou, Ioannis

    2018-02-19

    Existing cine imaging techniques rely on balanced steady-state free precession (bSSFP) or spoiled gradient-echo readouts, each of which has limitations. For instance, with bSSFP, artifacts occur from rapid through-plane flow and off-resonance effects. We hypothesized that a prototype cine technique, radial fast interrupted steady-state (FISS), could overcome these limitations. The technique was compared with standard cine bSSFP for cardiac function, coronary artery conspicuity, and aortic valve morphology. Given its advantageous properties, we further hypothesized that the cine FISS technique, in combination with arterial spin labeling (ASL), could provide an alternative to phase contrast for visualizing in-plane flow patterns within the aorta and branch vessels. The study was IRB-approved and subjects provided consent. Breath-hold cine FISS and bSSFP were acquired using similar imaging parameters. There was no significant difference in biplane left ventricular ejection fraction or cardiac image quality between the two techniques. Compared with cine bSSFP, cine FISS demonstrated a marked decrease in fat signal which improved conspicuity of the coronary arteries, while suppression of through-plane flow artifact on thin-slice cine FISS images improved visualization of the aortic valve. Banding artifacts in the subcutaneous tissues were reduced. In healthy subjects, dynamic flow patterns were well visualized in the aorta, coronary and renal arteries using cine FISS ASL, even when the slice was substantially thicker than the vessel diameter. Cine FISS demonstrates several benefits for cardiovascular imaging compared with cine bSSFP, including better suppression of fat signal and reduced artifacts from through-plane flow and off-resonance effects. The main drawback is a slight (~ 20%) decrease in temporal resolution. In addition, preliminary results suggest that cine FISS ASL provides a potential alternative to phase contrast techniques for in-plane flow

  20. Myocardial strain assessment by cine cardiac magnetic resonance imaging using non-rigid registration.

    Science.gov (United States)

    Tsadok, Yossi; Friedman, Zvi; Haluska, Brian A; Hoffmann, Rainer; Adam, Dan

    2016-05-01

    To evaluate a novel post-processing method for assessment of longitudinal mid-myocardial strain in standard cine cardiac magnetic resonance (CMR) imaging sequences. Cine CMR imaging and tagged cardiac magnetic resonance imaging (TMRI) were performed in 15 patients with acute myocardial infarction (AMI) and 15 healthy volunteers served as control group. A second group of 37 post-AMI patients underwent both cine CMR and late gadolinium enhancement (LGE) CMR exams. Speckle tracking echocardiography (STE) was performed in 36 of these patients. Cine CMR, TMRI and STE were analyzed to obtain longitudinal strain. LGE-CMR datasets were analyzed to evaluate scar extent. Comparison of peak systolic strain (PSS) measured from CMR and TMRI yielded a strong correlation (r=0.86, pcine CMR data. The method was found to be highly correlated with strain measurements obtained by TMRI and STE. This tool allows accurate discrimination between different transmurality states of myocardial infarction. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Usefulness of true FISP cine MR imaging in patients with poor cardiac function

    International Nuclear Information System (INIS)

    Sakuma, Toshiharu; Yamada, Naoaki; Motooka, Makoto; Enomoto, Naoyuki; Maeshima, Isamu; Matsuda, Kazuhide; Urayama, Shinichi; Ikeo, Miki

    2002-01-01

    This study was done to assess the value of True FISP cine in patients with poor cardiac function. True FISP cine and FLASH cine imaging were performed on a 1.5 T machine. Both short axis and horizontal long axis imaging sections were used. The imaging sections used a Matrix (120 x 128), FOV (24 x 32 cm), and had a slice thickness of 8 mm. The imaging time for True FISP cine was 8 heart beats and 17 heart beats for FLASH cine. The contrast-to-noise ratio between the blood and myocardium (CNR) was measured at enddiastole and endsystole. The subjects in the study were 10 healty volunteers (average age 26.5±3.2 years) and 12 patients with hypofunction (average age 53.9±13.2 years). In the volunteers, the CNR of the short axis imaging was similar in both True FISP (24.6±3.7) and FLASH (23.4±5.9). In the patients with poor cardiac function however, the CNR of True FISP was larger than FLASH in both the short and long axis. In the short axis (22.7±6.1 vs. 17.9±5.3, P<0.01) and in the long axis (17.4±4.3 vs. 9.3±4.0, P<0.01). We conclude that True FISP cine has a higher contrast in a shorter imaging time than FLASH cine. True FISP cine is especially useful in patients with poor cardiac function. (author)

  2. Motion-Corrected Real-Time Cine Magnetic Resonance Imaging of the Heart: Initial Clinical Experience.

    Science.gov (United States)

    Rahsepar, Amir Ali; Saybasili, Haris; Ghasemiesfe, Ahmadreza; Dolan, Ryan S; Shehata, Monda L; Botelho, Marcos P; Markl, Michael; Spottiswoode, Bruce; Collins, Jeremy D; Carr, James C

    2018-01-01

    Free-breathing real-time (RT) imaging can be used in patients with difficulty in breath-holding; however, RT cine imaging typically experiences poor image quality compared with segmented cine imaging because of low resolution. Here, we validate a novel unsupervised motion-corrected (MOCO) reconstruction technique for free-breathing RT cardiac images, called MOCO-RT. Motion-corrected RT uses elastic image registration to generate a single heartbeat of high-quality data from a free-breathing RT acquisition. Segmented balanced steady-state free precession (bSSFP) cine images and free-breathing RT images (Cartesian, TGRAPPA factor 4) were acquired with the same spatial/temporal resolution in 40 patients using clinical 1.5 T magnetic resonance scanners. The respiratory cycle was estimated using the reconstructed RT images, and nonrigid unsupervised motion correction was applied to eliminate breathing motion. Conventional segmented RT and MOCO-RT single-heartbeat cine images were analyzed to evaluate left ventricular (LV) function and volume measurements. Two radiologists scored images for overall image quality, artifact, noise, and wall motion abnormalities. Intraclass correlation coefficient was used to assess the reliability of MOCO-RT measurement. Intraclass correlation coefficient showed excellent reliability (intraclass correlation coefficient ≥ 0.95) of MOCO-RT with segmented cine in measuring LV function, mass, and volume. Comparison of the qualitative ratings indicated comparable image quality for MOCO-RT (4.80 ± 0.35) with segmented cine (4.45 ± 0.88, P = 0.215) and significantly higher than conventional RT techniques (3.51 ± 0.41, P cine (1.51 ± 0.90, P = 0.088 and 1.23 ± 0.45, P = 0.182) were not different. Wall motion abnormality ratings were comparable among different techniques (P = 0.96). The MOCO-RT technique can be used to process conventional free-breathing RT cine images and provides comparable quantitative assessment of LV function and volume

  3. Application of phase-contrast cine magnetic resonance imaging in endoscopic aqueductoplasty.

    Science.gov (United States)

    Chen, Guoqiang; Zheng, Jiaping; Xiao, Qing; Liu, Yunsheng

    2013-06-01

    The aim of this study was to evaluate the application of phase-contrast cine magnetic resonance imaging (MRI) in endoscopic aqueductoplasty (EA) for patients with obstructive hydrocephalus. The clinical diagnosis of hydrocephalus caused by aqueduct obstruction in 23 patients was confirmed by phase-contrast cine MRI examination. The patients were treated with EA and MRI was repeated during the follow-up. The cerebrospinal fluid (CSF) flow velocity in the aqueduct was measured to determine whether the aqueduct was obstructed. The results of phase-contrast cine MRI examinations indicated that there was no CSF flow in the aqueduct for all patients prior to surgery. Aqueductoplasty was successfully performed in all patients. The results of phase-contrast cine MRI examinations performed a week after surgery demonstrated an average CSF flow velocity of 4.74±1.77 cm/sec. During the follow-up, intracranial hypertension recurred in two patients in whom CSF flow was not observed in the aqueduct by the phase-contrast cine MRI scan. Aqueduct re-occlusion was revealed by an endoscopic exploration. By measuring the CSF flow velocity, phase-contrast cine MRI accurately identifies aqueduct obstruction. Cine MRI is a nontraumatic, simple and reliable method for determining whether the aqueduct is successfully opened following aqueductoplasty.

  4. Cine viability magnetic resonance imaging of the heart without increased scan time.

    Science.gov (United States)

    Hassanein, Azza S; Khalifa, Ayman M; Ibrahim, El-Sayed H

    2016-02-01

    Cardiac magnetic resonance imaging (MRI) provides information about myocardial morphology, function, and viability from cine, tagged, and late gadolinium enhancement (LGE) images, respectively. While the cine and tagged images are acquired in a time-resolved fashion, the LGE images are acquired at a single timeframe. The purpose of this work is to develop a method for generating cine LGE images without additional scan time. The motion field is extracted from the tagged images, and is then used to guide the deformation of the infarcted region from the acquired LGE image at the acquired timeframe to any other timeframe. Major techniques for motion estimation, including harmonic phase (HARP) and optical flow analysis, are tested in this work for motion estimation. The proposed method is tested on numerical phantom and images from four human subjects. The generated cine LGE images showed both viability and wall motion information in the same set of images without additional scan time or image misregistration problems. The band-pass optical flow analysis resulted in the most accurate motion estimation compared to other methods, especially HARP, which fails to track points at the myocardial boundary. Infarct transmurality from the generated images showed good agreement with myocardial strain, and wall thickening showed good agreement with that measured from conventional cine images. In conclusion, the developed technique allows for generating cine LGE images that enable simultaneous display of wall motion and viability information. The generated images could be useful for estimating myocardial contractility reserve and for treatment prognosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Overcoming pitfalls in the diagnosis of aortic dissection with phase-contrast cine MR imaging

    International Nuclear Information System (INIS)

    Herfkens, R.J.; Trefelner, E.C.; Jeffrey, R.B.; Pelc, N.J.; Steiner, R.M.; Francis, I.R.

    1991-01-01

    This paper evaluates whether phase contrast cine MR imaging improves the diagnostic accuracy in aortic dissection. Fifty-five MR examinations in 49 patients were analyzed. Gated coronal and axial spin-echo (SE) images and axial velocity encoded cine images were collected through the thoracic aorta. Blinded interpretations were obtained by first evaluating SE images, then SE and cine (magnitude) images, and finally with the addition of the velocity data for whether there was increase or decreased diagnostic confidence of aortic dissection. Comparisons were made with CT, angiography, and follow-up (including surgery). Fisher discriminant analysis showed that a statistically significant improvement in diagnostic accuracy was made by the addition of the velocity data in cases where a definite diagnosis of aortic dissection could not be made from the SE images alone

  6. Algebraic Reconstruction Technique (ART) for parallel imaging reconstruction of undersampled radial data: Application to cardiac cine

    Science.gov (United States)

    Li, Shu; Chan, Cheong; Stockmann, Jason P.; Tagare, Hemant; Adluru, Ganesh; Tam, Leo K.; Galiana, Gigi; Constable, R. Todd; Kozerke, Sebastian; Peters, Dana C.

    2014-01-01

    Purpose To investigate algebraic reconstruction technique (ART) for parallel imaging reconstruction of radial data, applied to accelerated cardiac cine. Methods A GPU-accelerated ART reconstruction was implemented and applied to simulations, point spread functions (PSF) and in twelve subjects imaged with radial cardiac cine acquisitions. Cine images were reconstructed with radial ART at multiple undersampling levels (192 Nr x Np = 96 to 16). Images were qualitatively and quantitatively analyzed for sharpness and artifacts, and compared to filtered back-projection (FBP), and conjugate gradient SENSE (CG SENSE). Results Radial ART provided reduced artifacts and mainly preserved spatial resolution, for both simulations and in vivo data. Artifacts were qualitatively and quantitatively less with ART than FBP using 48, 32, and 24 Np, although FBP provided quantitatively sharper images at undersampling levels of 48-24 Np (all pparallel radial MR imaging, providing reduced artifacts while mainly maintaining sharpness compared to FBP, as shown by its first application in cardiac studies. PMID:24753213

  7. SU-E-J-234: Application of a Breathing Motion Model to ViewRay Cine MR Images

    International Nuclear Information System (INIS)

    O’Connell, D. P.; Thomas, D. H.; Dou, T. H.; Lamb, J. M.; Yang, L.; Low, D. A.

    2015-01-01

    Purpose: A respiratory motion model previously used to generate breathing-gated CT images was used with cine MR images. Accuracy and predictive ability of the in-plane models were evaluated. Methods: Sagittalplane cine MR images of a patient undergoing treatment on a ViewRay MRI/radiotherapy system were acquired before and during treatment. Images were acquired at 4 frames/second with 3.5 × 3.5 mm resolution and a slice thickness of 5 mm. The first cine frame was deformably registered to following frames. Superior/inferior component of the tumor centroid position was used as a breathing surrogate. Deformation vectors and surrogate measurements were used to determine motion model parameters. Model error was evaluated and subsequent treatment cines were predicted from breathing surrogate data. A simulated CT cine was created by generating breathing-gated volumetric images at 0.25 second intervals along the measured breathing trace, selecting a sagittal slice and downsampling to the resolution of the MR cines. A motion model was built using the first half of the simulated cine data. Model accuracy and error in predicting the remaining frames of the cine were evaluated. Results: Mean difference between model predicted and deformably registered lung tissue positions for the 28 second preview MR cine acquired before treatment was 0.81 +/− 0.30 mm. The model was used to predict two minutes of the subsequent treatment cine with a mean accuracy of 1.59 +/− 0.63 mm. Conclusion: Inplane motion models were built using MR cine images and evaluated for accuracy and ability to predict future respiratory motion from breathing surrogate measurements. Examination of long term predictive ability is ongoing. The technique was applied to simulated CT cines for further validation, and the authors are currently investigating use of in-plane models to update pre-existing volumetric motion models used for generation of breathing-gated CT planning images

  8. Peristalsis gap sign at cine magnetic resonance imaging for diagnosing strangulated small bowel obstruction. Feasibility study

    International Nuclear Information System (INIS)

    Takahara, Taro; Kwee, T.C.; Haradome, Hiroki

    2011-01-01

    The aim of this study was to determine the feasibility of cine magnetic resonance imaging (MRI) for diagnosing strangulated small bowel obstruction (SBO). This study included 38 patients with clinically confirmed SBO who had undergone cine MRI. Cine MRI scans were evaluated regarding the presence of the 'peristalsis gap sign' (referring to an akinetic or severely hypokinetic closed loop), indicating strangulation. Computed tomography (CT) was performed in 34 of 38 patients with (n=25) or without (n=9) contrast enhancement. CT images were evaluated using a combination of criteria (presence of hyperattenuation, poor contrast enhancement, mesenteric edema, wall thickening, massive ascites) indicating strangulation. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of cine MRI and CT for the diagnosis of strangulation were calculated and compared using surgical findings and the clinical course as the reference standard. Sensitivity, specificity, PPV, and NPV of cine MRI were 100%, 92.9%, 83.3%, and 100%, respectively; and those of CT (of which 26.5% was performed without contrast enhancement) were 66.7%, 92.0%, 75.0%, and 88.5%, respectively. There was no significant difference in diagnostic accuracy between the two methods (P=0.375). Cine MRI is a feasible and promising technique for diagnosing strangulation. (author)

  9. Evaluation of atrial, ventricular and atrioventricular septal defects by cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Akagi, Teiji; Kato, Hirohisa; Kiyomatsu, Yumi; Saiki, Kuninobu; Suzuki, Kazushige; Eto, Takaharu

    1992-01-01

    Cine magnetic resonance imaging (MRI) was performed on 20 patients (mean age: 5.3±4.4 years) with atrial, ventricular, or atrioventricular septal defects for evaluation of cardiac structure and blood flow. Prior to cine MRI, electrocardiographycally gated MRI using multislice scquisition was performed on all patients to localize optimal slice location. Cine-MRI was obtained with a 30 deg flip angle, 15 msec echo time, and 30 msec pulse repetition time, on a 256 x 256 or 128 x 128 acquisition matrix. Abnormalities of cardiac structure were well defined in all patients by gated cardiac imaging. In 18 of the 20 patients, cine-MRI was able to detect shunt flow, visualized as a low intensity signal in comparison with the surrounding blood flow. Cine-MRI can provide not only accurate anatomy of cardiac structures but functional assessment of the cardiac chamber, wall topology and flow relations. Cine-MRI will become an important noninvasive technique for assessment of anatomy and physiology in congenital heart disease. (author)

  10. Three-dimensional visualization of myocardial motion and blood flow with cine-MR images

    International Nuclear Information System (INIS)

    Oshiro, Osamu; Matani, Ayumu; Chihara, Kunihiro; Mikami, Taisei; Kitabatake, Akira.

    1997-01-01

    This paper describes a three-dimensional (3D) reconstruction and presentation method to visualize myocardial motion and blood flow in a heart using cine-MR (magnetic resonance) images. Firstly, the region of myocardium and blood were segmented with certain threshold gray values. Secondly, some slices were interpolated linearly to reconstruct a 3D static image. Finally, a 3D dynamic image was presented with displaying the 3D static images sequentially. The experimental results indicate that this method enables to visualize not only normal but also abnormal blood flow in cine-mode. (author)

  11. Cine MR imaging of uterine peristalsis in patients with endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Kido, Aki; Togashi, Kaori; Koyama, Takashi; Fujimoto, Ryota [Kyoto University, Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto (Japan); Nishino, Mizuki [Beth Israel Deaconess Medical Center, Department of Radiology, Kyoto (Japan); Miyake, Kanae; Hayakawa, Katsumi [Kyoto City Hospital, Department of Radiology, Kyoto (Japan); Iwasaku, Kazuhiro [Kyoto City Hospital, Department of Obstetrics and Gynecology, Kyoto (Japan); Fujii, Shingo [Kyoto University, Department of Gynecology and Obstetrics, Kyoto (Japan)

    2007-07-15

    Endometriosis is one of the most important causes of infertility; however the precise mechanism by which it affects female fertility is unclear. The objective of this study was to study the functional aspects of the uterus by evaluating uterine contractility in patients with endometrial cysts of the ovary. The study population was recruited from two institutes and consisted of 26 women (periovulatory (10), luteal (13), and menstrual phase (3); age range: 19-51 years) with untreated endometriosis; the control group consisted of 12 healthy women (age range: 22-41 years). Cine MR imaging obtained by a 1.5T magnet was visually evaluated at 12 x faster than real speed, focusing on the presence of uterine peristalsis, the direction and frequency of peristalsis, and the presence of sustained uterine contractions. Uterine peristalsis was identifiable in 3/10, 3/13, and 3/3 of the endometriosis patients in each menstrual cycle, respectively, and in 11/12, 3/12, and 5/12 of their control subjects. Peristaltic detection rate and frequency were significantly less for the endometriosis group than for the controls in the periovulatory phase only (p<0.05). Sustained contractions were recognized in 19/36 control subjects and in 13/26 endometriosis patients, but the difference was not significant. Uterine peristalsis appears to be suppressed during the periovulatory phase in patients with endometriosis, which may have an adverse effect on sperm transport. (orig.)

  12. Cine MR imaging of uterine peristalsis in patients with endometriosis

    International Nuclear Information System (INIS)

    Kido, Aki; Togashi, Kaori; Koyama, Takashi; Fujimoto, Ryota; Nishino, Mizuki; Miyake, Kanae; Hayakawa, Katsumi; Iwasaku, Kazuhiro; Fujii, Shingo

    2007-01-01

    Endometriosis is one of the most important causes of infertility; however the precise mechanism by which it affects female fertility is unclear. The objective of this study was to study the functional aspects of the uterus by evaluating uterine contractility in patients with endometrial cysts of the ovary. The study population was recruited from two institutes and consisted of 26 women (periovulatory (10), luteal (13), and menstrual phase (3); age range: 19-51 years) with untreated endometriosis; the control group consisted of 12 healthy women (age range: 22-41 years). Cine MR imaging obtained by a 1.5T magnet was visually evaluated at 12 x faster than real speed, focusing on the presence of uterine peristalsis, the direction and frequency of peristalsis, and the presence of sustained uterine contractions. Uterine peristalsis was identifiable in 3/10, 3/13, and 3/3 of the endometriosis patients in each menstrual cycle, respectively, and in 11/12, 3/12, and 5/12 of their control subjects. Peristaltic detection rate and frequency were significantly less for the endometriosis group than for the controls in the periovulatory phase only (p<0.05). Sustained contractions were recognized in 19/36 control subjects and in 13/26 endometriosis patients, but the difference was not significant. Uterine peristalsis appears to be suppressed during the periovulatory phase in patients with endometriosis, which may have an adverse effect on sperm transport. (orig.)

  13. Subacute and Chronic Left Ventricular Myocardial Scar: Accuracy of Texture Analysis on Nonenhanced Cine MR Images.

    Science.gov (United States)

    Baessler, Bettina; Mannil, Manoj; Oebel, Sabrina; Maintz, David; Alkadhi, Hatem; Manka, Robert

    2018-01-01

    Purpose To test whether texture analysis (TA) allows for the diagnosis of subacute and chronic myocardial infarction (MI) on noncontrast material-enhanced cine cardiac magnetic resonance (MR) images. Materials and Methods In this retrospective, institutional review board-approved study, 120 patients who underwent cardiac MR imaging and showed large transmural (volume of enhancement on late gadolinium enhancement [LGE] images >20%, n = 72) or small (enhanced volume ≤20%, n = 48) subacute or chronic ischemic scars were included. Sixty patients with normal cardiac MR imaging findings served as control subjects. Regions of interest for TA encompassing the left ventricle were drawn by two blinded, independent readers on cine images in end systole by using a freely available software package. Stepwise dimension reduction and texture feature selection based on reproducibility, machine learning, and correlation analyses were performed for selecting features, enabling the diagnosis of MI on nonenhanced cine MR images by using LGE imaging as the standard of reference. Results Five independent texture features allowed for differentiation between ischemic scar and normal myocardium on cine MR images in both subgroups: Teta1, Perc.01, Variance, WavEnHH.s-3, and S(5,5)SumEntrp (in patients with large MI: all P values cine MR images, with an area under the curve of 0.93 and 0.92, respectively. Conclusion This proof-of-concept study indicates that TA of nonenhanced cine MR images allows for the diagnosis of subacute and chronic MI with high accuracy. © RSNA, 2017 Online supplemental material is available for this article.

  14. SU-E-J-61: Monitoring Tumor Motion in Real-Time with EPID Imaging During Cervical Cancer Treatment

    International Nuclear Information System (INIS)

    Mao, W; Hrycushko, B; Yan, Y; Foster, R; Albuquerque, K

    2015-01-01

    Purpose: Traditional external beam radiotherapy for cervical cancer requires setup by external skin marks. In order to improve treatment accuracy and reduce planning margin for more conformal therapy, it is essential to monitor tumor positions interfractionally and intrafractionally. We demonstrate feasibility of monitoring cervical tumor motion online using EPID imaging from Beam’s Eye View. Methods: Prior to treatment, 1∼2 cylindrical radio opaque markers were implanted into inferior aspect of cervix tumor. During external beam treatments on a Varian 2100C by 4-field 3D plans, treatment beam images were acquired continuously by an EPID. A Matlab program was developed to locate internal markers on MV images. Based on 2D marker positions obtained from different treatment fields, their 3D positions were estimated for every treatment fraction. Results: There were 398 images acquired during different treatment fractions of three cervical cancer patients. Markers were successfully located on every frame of image at an analysis speed of about 1 second per frame. Intrafraction motions were evaluated by comparing marker positions relative to the position on the first frame of image. The maximum intrafraction motion of the markers was 1.6 mm. Interfraction motions were evaluated by comparing 3D marker positions at different treatment fractions. The maximum interfraction motion was up to 10 mm. Careful comparison found that this is due to patient positioning since the bony structures shifted with the markers. Conclusion: This method provides a cost-free and simple solution for online tumor tracking for cervical cancer treatment since it is feasible to acquire and export EPID images with fast analysis in real time. This method does not need any extra equipment or deliver extra dose to patients. The online tumor motion information will be very useful to reduce planning margins and improve treatment accuracy, which is particularly important for SBRT treatment with long

  15. SU-E-J-61: Monitoring Tumor Motion in Real-Time with EPID Imaging During Cervical Cancer Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Mao, W; Hrycushko, B; Yan, Y; Foster, R; Albuquerque, K [UT Southwestern Medical Center, Dallas, TX (United States)

    2015-06-15

    Purpose: Traditional external beam radiotherapy for cervical cancer requires setup by external skin marks. In order to improve treatment accuracy and reduce planning margin for more conformal therapy, it is essential to monitor tumor positions interfractionally and intrafractionally. We demonstrate feasibility of monitoring cervical tumor motion online using EPID imaging from Beam’s Eye View. Methods: Prior to treatment, 1∼2 cylindrical radio opaque markers were implanted into inferior aspect of cervix tumor. During external beam treatments on a Varian 2100C by 4-field 3D plans, treatment beam images were acquired continuously by an EPID. A Matlab program was developed to locate internal markers on MV images. Based on 2D marker positions obtained from different treatment fields, their 3D positions were estimated for every treatment fraction. Results: There were 398 images acquired during different treatment fractions of three cervical cancer patients. Markers were successfully located on every frame of image at an analysis speed of about 1 second per frame. Intrafraction motions were evaluated by comparing marker positions relative to the position on the first frame of image. The maximum intrafraction motion of the markers was 1.6 mm. Interfraction motions were evaluated by comparing 3D marker positions at different treatment fractions. The maximum interfraction motion was up to 10 mm. Careful comparison found that this is due to patient positioning since the bony structures shifted with the markers. Conclusion: This method provides a cost-free and simple solution for online tumor tracking for cervical cancer treatment since it is feasible to acquire and export EPID images with fast analysis in real time. This method does not need any extra equipment or deliver extra dose to patients. The online tumor motion information will be very useful to reduce planning margins and improve treatment accuracy, which is particularly important for SBRT treatment with long

  16. Cine MR imaging before and after realignment surgery for patellar maltracking - comparison with axial radiographs

    International Nuclear Information System (INIS)

    Brossmann, J.; Muhle, C.; Buell, C.C.; Zieplies, J.; Melchert, U.H.; Brinkmann, G.; Schroeder, C.; Heller, M.

    1995-01-01

    Comparison of motion-triggered cine magnetic resonance (MR) imaging and conventional radiographs for the assessment of operative results of patellar realignment. Fifteen patients with recurrent patellar dislocation or patellar subluxation were evaluated with conventional axial radiographs before and after realignment surgery by measuring the congruence angle (CA), lateral patellofemoral angle (LPFA), and lateral displacement (d). In eight patients the patellofemoral joint was additionally evaluated pre- and postoperatively with motion-triggered cine MR imaging by determining the bisect offset (BSO), lateral patellar displacement (LPD), and patellar tilt angle (PTA). Significant differences between the pre- and postoperative measurements were found for all MR imaging parameters (BSO, LPD, PTA: p<0.01) but not for the conventional X-ray parameters (CA: p=0.70, LPFA: p=0.56; d: p=0.04). Motion-triggered cine MR imaging was superior to conventional tangential radiographs for assessing the effectiveness of patellar realignment surgery. (orig.)

  17. Cine MR imaging before and after realignment surgery for patellar maltracking - comparison with axial radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Brossmann, J. [Klinik fuer Radiologische Diagnostik der Univ. Kiel (Germany); Muhle, C. [Klinik fuer Radiologische Diagnostik der Univ. Kiel (Germany); Buell, C.C. [Rheumaklinik, Bad Bramstedt (Germany); Zieplies, J. [Lubinus Klinik, Kiel (Germany); Melchert, U.H. [Klinik fuer Radiologische Diagnostik der Univ. Kiel (Germany); Brinkmann, G. [Klinik fuer Radiologische Diagnostik der Univ. Kiel (Germany); Schroeder, C. [Klinik fuer Radiologische Diagnostik der Univ. Kiel (Germany); Heller, M. [Klinik fuer Radiologische Diagnostik der Univ. Kiel (Germany)

    1995-04-01

    Comparison of motion-triggered cine magnetic resonance (MR) imaging and conventional radiographs for the assessment of operative results of patellar realignment. Fifteen patients with recurrent patellar dislocation or patellar subluxation were evaluated with conventional axial radiographs before and after realignment surgery by measuring the congruence angle (CA), lateral patellofemoral angle (LPFA), and lateral displacement (d). In eight patients the patellofemoral joint was additionally evaluated pre- and postoperatively with motion-triggered cine MR imaging by determining the bisect offset (BSO), lateral patellar displacement (LPD), and patellar tilt angle (PTA). Significant differences between the pre- and postoperative measurements were found for all MR imaging parameters (BSO, LPD, PTA: p<0.01) but not for the conventional X-ray parameters (CA: p=0.70, LPFA: p=0.56; d: p=0.04). Motion-triggered cine MR imaging was superior to conventional tangential radiographs for assessing the effectiveness of patellar realignment surgery. (orig.)

  18. The Role of Cine Flow Magnetic Resonance Imaging in Patients with Chiari 0 Malformation.

    Science.gov (United States)

    Ozsoy, Kerem Mazhar; Oktay, Kadir; Cetinalp, Nuri Eralp; Gezercan, Yurdal; Erman, Tahsin

    2018-01-01

    To define the role of phase-contrast cine magnetic resonance imaging (MRI) in deciding the therapeutic strategy and underlying pathophysiology resulting in syrinx formation in patients with Chiari type 0 malformation. Seven patients who were admitted to our clinic with the diagnosis of Chiari 0 malformation from January 2005 to July 2016 were enrolled in the study. All patients underwent a detailed preoperative neurological examination. Entire neuroaxis MRI and phase-contrast cine MRI were obtained preoperatively and postoperatively. Seven patients (5 female and 2 male) with Chiari type 0 malformation fulfilled the inclusion criteria. All of the patients had absent cine flow at the craniovertebral junction except two patients. These five patients underwent surgical interventions; suboccipital decompression and duraplasty. All of them showed both clinical and radiological improvement in the postoperative period. Cine flow MRI appears to be a useful tool in the management of patients with Chiari 0 malformation. There was a good correlation between the clinical presentation and cine flow preoperatively, and between clinical improvement and cine flow in the postoperative period.

  19. Free-breathing whole-heart 3D cine magnetic resonance imaging with prospective respiratory motion compensation.

    Science.gov (United States)

    Moghari, Mehdi H; Barthur, Ashita; Amaral, Maria E; Geva, Tal; Powell, Andrew J

    2018-07-01

    To develop and validate a new prospective respiratory motion compensation algorithm for free-breathing whole-heart 3D cine steady-state free precession (SSFP) imaging. In a 3D cine SSFP sequence, 4 excitations per cardiac cycle are re-purposed to prospectively track heart position. Specifically, their 1D image is reconstructed and routed into the scanner's standard diaphragmatic navigator processing system. If all 4 signals are in end-expiration, cine image data from the entire cardiac cycle is accepted for image reconstruction. Prospective validation was carried out in patients (N = 17) by comparing in each a conventional breath-hold 2D cine ventricular short-axis stack and a free-breathing whole-heart 3D cine data set. All 3D cine SSFP acquisitions were successful and the mean scan time was 5.9 ± 2.7 min. Left and right ventricular end-diastolic, end-systolic, and stroke volumes by 3D cine SSFP were all larger than those from 2D cine SSFP. This bias was cine images had a lower ventricular blood-to-myocardium contrast ratio, contrast-to-noise ratio, mass, and subjective quality score. The novel prospective respiratory motion compensation method for 3D cine SSFP imaging was robust and efficient and yielded slightly larger ventricular volumes and lower mass compared to breath-hold 2D cine imaging. Magn Reson Med 80:181-189, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  20. Evaluation of valvular regurgitation by cine magnetic resonance imaging in patients with various cardiac diseases

    International Nuclear Information System (INIS)

    Kubota, Shuuhei; Nishimura, Tsunehiko

    1990-01-01

    In order to evaluate the clinical value and limitation of magnetic resonance imaging (MRI) for detection and quantification of valvular regurgitation, 98 patients with various cardiac diseases were studied by cine MRI and the results were compared with contrast angiography and doppler color-flow imaging. Cine MRI was carried out using FLASH (fast low angle shot) which employs TE of 10∼20 msec and TR of 30∼40 msec. 22 transverse tomograms per cardiac cycle with a slice thickness of 10 mm were obtained at the level of atrium and ventricle. The jet of valvular regurgitation was easily seen as a discrete are of low signal with cine MRI. Identification of the regurgitation and its severity were visually evaluated based on the relative size of the regurgitant jet from the incompetent valve orifice. Using contrast angiography as a gold standard, the sensitivity of cine MRI for detecting mitral regurgitation was 83% and was 94% for aortic regurgitation, with the specificity of 82% and 100%, respectively. For mitral requrgitation and aortic regurgitation, evaluation by cine MRI and severity agreed well with contrast angiography. By the comparative study with doppler color-flow imaging, relatively good agreement was found between the two methods in detection and quantitative evaluation of valvular regurgitation in any of four valves. Cine MRI was suggested to be useful for both the detection and semiquantification of valvular regurgitation in generally, but its clinical limitation at this point was also found because, 1)its images are not acquired in real times, as in contrast angiography or doppler color-flow imaging, but are compiled from the cumulative information from 128 heart beats, 2)the evaluation of regurgitation is made from only two-dimensional transverse tomograms. (author)

  1. Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images

    Energy Technology Data Exchange (ETDEWEB)

    Zweerink, Alwin; Allaart, Cornelis P.; Wu, LiNa; Beek, Aernout M.; Rossum, Albert C. van; Nijveldt, Robin [VU University Medical Center, Department of Cardiology, and Institute for Cardiovascular Research (ICaR-VU), Amsterdam (Netherlands); Kuijer, Joost P.A. [VU University Medical Center, Department of Physics and Medical Technology, Amsterdam (Netherlands); Ven, Peter M. van de [VU University Medical Center, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands); Meine, Mathias [University Medical Center, Department of Cardiology, Utrecht (Netherlands); Croisille, Pierre; Clarysse, Patrick [Univ Lyon, UJM-Saint-Etienne, INSA, CNRS UMR 5520, INSERM U1206, CREATIS, Saint-Etienne (France)

    2017-12-15

    Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive segmental strains from standard cardiovascular MR (CMR) cine images in CRT candidates. Twenty-seven patients with left bundle branch block underwent CMR examination including cine imaging and myocardial tagging (CMR-TAG). SLICE was performed by measuring segment length between anatomical landmarks throughout all phases on short-axis cines. This measure of frame-to-frame segment length change was compared to CMR-TAG circumferential strain measurements. Subsequently, conventional markers of CRT response were calculated. Segmental strains showed good to excellent agreement between SLICE and CMR-TAG (septum strain, intraclass correlation coefficient (ICC) 0.76; lateral wall strain, ICC 0.66). Conventional markers of CRT response also showed close agreement between both methods (ICC 0.61-0.78). Reproducibility of SLICE was excellent for intra-observer testing (all ICC ≥0.76) and good for interobserver testing (all ICC ≥0.61). The novel SLICE post-processing technique on standard CMR cine images offers both accurate and robust segmental strain measures compared to the 'gold standard' CMR-TAG technique, and has the advantage of being widely available. (orig.)

  2. Higher resolution cine imaging with compressed sensing for accelerated clinical left ventricular evaluation.

    Science.gov (United States)

    Lin, Aaron C W; Strugnell, Wendy; Riley, Robyn; Schmitt, Benjamin; Zenge, Michael; Schmidt, Michaela; Morris, Norman R; Hamilton-Craig, Christian

    2017-06-01

    To assess the clinical feasibility of a compressed sensing cine magnetic resonance imaging (MRI) sequence of both high temporal and spatial resolution (CS_bSSFP) in comparison to a balanced steady-state free precession cine (bSSFP) sequence for reliable quantification of left ventricular (LV) volumes and mass. Segmented MRI cine images were acquired on a 1.5T scanner in 50 patients in the LV short-axis stack orientation using a retrospectively gated conventional bSSFP sequence (generalized autocalibrating partially parallel acquisition [GRAPPA] acceleration factor 2), followed by a prospectively triggered CS_bSSFP sequence with net acceleration factor of 8. Image quality was assessed by published criteria. Comparison of sequences was made in LV volumes and mass, image quality score, quantitative regional myocardial wall motion, and imaging time using Pearson's correlation, Bland-Altman and paired 2-tailed Student's t-test. Differences (bSSFP minus CS_bSSFP, mean ± SD) and Pearson's correlations were 14.8 ± 16.3 (P = 0.31) and r = 0.98 (P cine CS_bSSFP accurately and reliably quantitates LV volumes and mass, shortens acquisition times, and is clinically feasible. 1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1693-1699. © 2016 International Society for Magnetic Resonance in Medicine.

  3. Accelerated two-dimensional cine DENSE cardiovascular magnetic resonance using compressed sensing and parallel imaging.

    Science.gov (United States)

    Chen, Xiao; Yang, Yang; Cai, Xiaoying; Auger, Daniel A; Meyer, Craig H; Salerno, Michael; Epstein, Frederick H

    2016-06-14

    Cine Displacement Encoding with Stimulated Echoes (DENSE) provides accurate quantitative imaging of cardiac mechanics with rapid displacement and strain analysis; however, image acquisition times are relatively long. Compressed sensing (CS) with parallel imaging (PI) can generally provide high-quality images recovered from data sampled below the Nyquist rate. The purposes of the present study were to develop CS-PI-accelerated acquisition and reconstruction methods for cine DENSE, to assess their accuracy for cardiac imaging using retrospective undersampling, and to demonstrate their feasibility for prospectively-accelerated 2D cine DENSE imaging in a single breathhold. An accelerated cine DENSE sequence with variable-density spiral k-space sampling and golden angle rotations through time was implemented. A CS method, Block LOw-rank Sparsity with Motion-guidance (BLOSM), was combined with sensitivity encoding (SENSE) for the reconstruction of under-sampled multi-coil spiral data. Seven healthy volunteers and 7 patients underwent 2D cine DENSE imaging with fully-sampled acquisitions (14-26 heartbeats in duration) and with prospectively rate-2 and rate-4 accelerated acquisitions (14 and 8 heartbeats in duration). Retrospectively- and prospectively-accelerated data were reconstructed using BLOSM-SENSE and SENSE. Image quality of retrospectively-undersampled data was quantified using the relative root mean square error (rRMSE). Myocardial displacement and circumferential strain were computed for functional assessment, and linear correlation and Bland-Altman analyses were used to compare accelerated acquisitions to fully-sampled reference datasets. For retrospectively-undersampled data, BLOSM-SENSE provided similar or lower rRMSE at rate-2 and lower rRMSE at rate-4 acceleration compared to SENSE (p cine DENSE provided good image quality and expected values of displacement and strain. BLOSM-SENSE-accelerated spiral cine DENSE imaging with 2D displacement encoding can be

  4. Right ventricular volume and mass determined by cine magnetic resonance imaging in HIV patients with possible right ventricular dysfunction

    DEFF Research Database (Denmark)

    Kjaer, Andreas; Lebech, Anne-Mette; Gerstoft, Jan

    2006-01-01

    Impaired right ventricular (RV) function has been reported to occur in patients with HIV when studied by echocardiography. However, for accurate evaluation of RV function and morphology, first-pass radionuclide ventriculography (RNV) and cine magnetic resonance imaging (cine-MRI) are methods...

  5. Automatic segmentation of left ventricle in cardiac cine MRI images based on deep learning

    Science.gov (United States)

    Zhou, Tian; Icke, Ilknur; Dogdas, Belma; Parimal, Sarayu; Sampath, Smita; Forbes, Joseph; Bagchi, Ansuman; Chin, Chih-Liang; Chen, Antong

    2017-02-01

    In developing treatment of cardiovascular diseases, short axis cine MRI has been used as a standard technique for understanding the global structural and functional characteristics of the heart, e.g. ventricle dimensions, stroke volume and ejection fraction. To conduct an accurate assessment, heart structures need to be segmented from the cine MRI images with high precision, which could be a laborious task when performed manually. Herein a fully automatic framework is proposed for the segmentation of the left ventricle from the slices of short axis cine MRI scans of porcine subjects using a deep learning approach. For training the deep learning models, which generally requires a large set of data, a public database of human cine MRI scans is used. Experiments on the 3150 cine slices of 7 porcine subjects have shown that when comparing the automatic and manual segmentations the mean slice-wise Dice coefficient is about 0.930, the point-to-curve error is 1.07 mm, and the mean slice-wise Hausdorff distance is around 3.70 mm, which demonstrates the accuracy and robustness of the proposed inter-species translational approach.

  6. Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images.

    Science.gov (United States)

    Zweerink, Alwin; Allaart, Cornelis P; Kuijer, Joost P A; Wu, LiNa; Beek, Aernout M; van de Ven, Peter M; Meine, Mathias; Croisille, Pierre; Clarysse, Patrick; van Rossum, Albert C; Nijveldt, Robin

    2017-12-01

    Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive segmental strains from standard cardiovascular MR (CMR) cine images in CRT candidates. Twenty-seven patients with left bundle branch block underwent CMR examination including cine imaging and myocardial tagging (CMR-TAG). SLICE was performed by measuring segment length between anatomical landmarks throughout all phases on short-axis cines. This measure of frame-to-frame segment length change was compared to CMR-TAG circumferential strain measurements. Subsequently, conventional markers of CRT response were calculated. Segmental strains showed good to excellent agreement between SLICE and CMR-TAG (septum strain, intraclass correlation coefficient (ICC) 0.76; lateral wall strain, ICC 0.66). Conventional markers of CRT response also showed close agreement between both methods (ICC 0.61-0.78). Reproducibility of SLICE was excellent for intra-observer testing (all ICC ≥0.76) and good for interobserver testing (all ICC ≥0.61). The novel SLICE post-processing technique on standard CMR cine images offers both accurate and robust segmental strain measures compared to the 'gold standard' CMR-TAG technique, and has the advantage of being widely available. • Myocardial strain analysis could potentially improve patient selection for CRT. • Currently a well validated clinical approach to derive segmental strains is lacking. • The novel SLICE technique derives segmental strains from standard CMR cine images. • SLICE-derived strain markers of CRT response showed close agreement with CMR-TAG. • Future studies will focus on the prognostic value of SLICE in CRT candidates.

  7. Functional imaging of murine hearts using accelerated self-gated UTE cine MRI

    NARCIS (Netherlands)

    Motaal, Abdallah G.; Noorman, Nils; de Graaf, Wolter L.; Hoerr, Verena; Florack, Luc M. J.; Nicolay, Klaas; Strijkers, Gustav J.

    2015-01-01

    We introduce a fast protocol for ultra-short echo time (UTE) Cine magnetic resonance imaging (MRI) of the beating murine heart. The sequence involves a self-gated UTE with golden-angle radial acquisition and compressed sensing reconstruction. The self-gated acquisition is performed asynchronously

  8. Analysis of 3-D Tongue Motion from Tagged and Cine Magnetic Resonance Images

    Science.gov (United States)

    Xing, Fangxu; Woo, Jonghye; Lee, Junghoon; Murano, Emi Z.; Stone, Maureen; Prince, Jerry L.

    2016-01-01

    Purpose: Measuring tongue deformation and internal muscle motion during speech has been a challenging task because the tongue deforms in 3 dimensions, contains interdigitated muscles, and is largely hidden within the vocal tract. In this article, a new method is proposed to analyze tagged and cine magnetic resonance images of the tongue during…

  9. SU-D-201-06: Remote Dosmetric Auditing of VMAT Deliveries for Clinical Trials Using EPID

    Energy Technology Data Exchange (ETDEWEB)

    Legge, K; Miri, N [University of Newcastle (Australia); Lehmann, J [Calvary Mater Newcastle (Australia); Vial, P [Liverpool Hospital (Australia); Greer, P [University of Newcastle (Australia); Calvary Mater Newcastle (Australia)

    2016-06-15

    Purpose: To develop a method for remote dosimetric auditing the delivery of VMAT using EPID which allows for simple, inexpensive and time efficient dosimetric credentialing for clinical trials. Methods: Remote centers are provided with CT datasets and planning guidelines to produce VMAT plans for a head and neck and a post-prostatectomy treatment. Plans are transferred in the planning system to two virtual water equivalent phantoms, one flat and one cylindrical. Cine images are acquired during VMAT delivery to the EPID in air with gantry angle recorded in image headers. Centers also deliver provided calibration plans to enable EPID signal to dose conversion, determination of the central axis, and correction of EPID sag prior to analysis. EPID images and planned doses are sent to the central site. EPID cine images are converted to dose in the virtual phantoms using an established backprojection method (King et al., Med.Phys. 2012) with EPID backscatter correction. Individual arcs (with gantry angles collapsed to zero) are evaluated at 10 cm depth in the flat phantom using 2D gamma, and total doses are evaluated in the cylindrical phantom using 3D gamma. Results are reported for criteria of 3%,3mm, 3%,2mm and 2%,2mm for all points greater than 10% of global maximum. Results: The pilot study for Varian centers has commenced, and three centers have been audited for head and neck plans and two for post-prostatectomy plans to date. The mean pass rate for arc-by-arc 2D analysis at 3%,3mm is 99.5% and for 3D analysis is 95.8%. A method for Elekta linacs using an inclinometer for gantry angle information is under development. Conclusion: Preliminary results for this new method are promising. The method takes advantage of EPID equipment available at most centers and clinically established software to provide a feasible, low cost solution to credentialing centers for clinical trials. Funding has been provided from Calvary Mater Newcastle Department of Radiation Oncology, TROG

  10. Functional imaging of murine hearts using accelerated self-gated UTE cine MRI.

    Science.gov (United States)

    Motaal, Abdallah G; Noorman, Nils; de Graaf, Wolter L; Hoerr, Verena; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

    2015-01-01

    We introduce a fast protocol for ultra-short echo time (UTE) Cine magnetic resonance imaging (MRI) of the beating murine heart. The sequence involves a self-gated UTE with golden-angle radial acquisition and compressed sensing reconstruction. The self-gated acquisition is performed asynchronously with the heartbeat, resulting in a randomly undersampled kt-space that facilitates compressed sensing reconstruction. The sequence was tested in 4 healthy rats and 4 rats with chronic myocardial infarction, approximately 2 months after surgery. As a control, a non-accelerated self-gated multi-slice FLASH sequence with an echo time (TE) of 2.76 ms, 4.5 signal averages, a matrix of 192 × 192, and an acquisition time of 2 min 34 s per slice was used to obtain Cine MRI with 15 frames per heartbeat. Non-accelerated UTE MRI was performed with TE = 0.29 ms, a reconstruction matrix of 192 × 192, and an acquisition time of 3 min 47 s per slice for 3.5 averages. Accelerated imaging with 2×, 4× and 5× undersampled kt-space data was performed with 1 min, 30 and 15 s acquisitions, respectively. UTE Cine images up to 5× undersampled kt-space data could be successfully reconstructed using a compressed sensing algorithm. In contrast to the FLASH Cine images, flow artifacts in the UTE images were nearly absent due to the short echo time, simplifying segmentation of the left ventricular (LV) lumen. LV functional parameters derived from the control and the accelerated Cine movies were statistically identical.

  11. Assessment of Bladder Motion for Clinical Radiotherapy Practice Using Cine-Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    McBain, Catherine A.; Khoo, Vincent S.; Buckley, David L.; Sykes, Jonathan S.; Green, Melanie M.; Cowan, Richard A.; Hutchinson, Charles E.; Moore, Christopher J.; Price, Patricia M.

    2009-01-01

    Purpose: Organ motion is recognized as the principal source of inaccuracy in bladder radiotherapy (RT), but there is currently little information on intrafraction bladder motion. Methods and Materials: We used cine-magnetic resonance imaging (cine-MRI) to study bladder motion relevant to intrafraction RT delivery. On two occasions, a 28 minute cine-MRI sequence was acquired from 10 bladder cancer patients and 5 control participants immediately after bladder emptying, after abstinence from drinking for the preceding hour. From the resulting cine sequences, bladder motion was subjectively assessed. To quantify bladder motion, the bladder was contoured in imaging volume sets at 0, 14, and 28 min to measure changes to bladder volumes, wall displacements, and center of gravity (COG) over time. Results: The dominant source of bladder motion during imaging was bladder filling (up to 101% volume increase); rectal and small bowel movements were transient, with minimal impact. Bladder volume changes were similar for all participants. However for bladder cancer patients, wall displacements were larger (up to 58 mm), less symmetrical, and more variable compared with nondiseased control bladders. Conclusions: Significant and individualized intrafraction bladder wall displacements may occur during bladder RT delivery. This important source of inaccuracy should be incorporated into treatment planning and verification.

  12. SU-E-T-775: Use of Electronic Portal Imaging Device (EPID) for Quality Assurance (QA) of Electron Beams On Varian Truebeam System

    Energy Technology Data Exchange (ETDEWEB)

    Cai, B; Yaddanapudi, S; Sun, B; Li, H; Noel, C; Mutic, S; Goddu, S [Department of Radiation Oncology, Washington University in St Louis, St. Louis, MO (United States)

    2015-06-15

    Purpose: In a previous study we have demonstrated the feasibility of using EPID to QA electron beam parameters on a single Varian TrueBeam LINAC. This study aims to provide further investigation on (1) reproducibility of using EPID to detect electron beam energy changes on multiple machines and (2) evaluation of appropriate calibration methods to compare results from different EPIDs. Methods: Ad-hoc mode electron beam images were acquired in developer mode with XML code. Electron beam data were collected on a total of six machines from four institutions. A custom-designed double-wedge phantom was placed on the EPID detector. Two calibration methods - Pixel Sensitivity Map (PSM) and Large Source-to-Imager Distance Flood Field (LSID-FF) - were used. To test the sensitivity of EPID in detecting energy drifts, Bending Magnet Current (BMC) was detuned to invoke energy changes corresponding to ∼±1.5 mm change in R50% of PDD on two machines from two institutions. Percent depth ionization (PDI) curves were then analyzed and compared with the respective baseline images using LSID-FF calibration. For reproducibility testing, open field EPID images and images with a standard testing phantom were collected on multiple machines. Images with and without PSM correction for same energies on different machines were overlaid and compared. Results: Two pixel shifts were observed in PDI curve when energy changes exceeded the TG142 tolerance. PSM showed the potential to correct the differences in pixel response of different imagers. With PSM correction, the histogram of images differences obtained from different machines showed narrower distributions than those images without PSM correction. Conclusion: EPID is sensitive for electron energy changes and the results are reproducible on different machines. When overlaying images from different machines, PSM showed the ability to partially eliminate the intrinsic variation of various imagers. Research Funding from Varian Medical Systems

  13. Real-time SPARSE-SENSE cardiac cine MR imaging: optimization of image reconstruction and sequence validation.

    Science.gov (United States)

    Goebel, Juliane; Nensa, Felix; Bomas, Bettina; Schemuth, Haemi P; Maderwald, Stefan; Gratz, Marcel; Quick, Harald H; Schlosser, Thomas; Nassenstein, Kai

    2016-12-01

    Improved real-time cardiac magnetic resonance (CMR) sequences have currently been introduced, but so far only limited practical experience exists. This study aimed at image reconstruction optimization and clinical validation of a new highly accelerated real-time cine SPARSE-SENSE sequence. Left ventricular (LV) short-axis stacks of a real-time free-breathing SPARSE-SENSE sequence with high spatiotemporal resolution and of a standard segmented cine SSFP sequence were acquired at 1.5 T in 11 volunteers and 15 patients. To determine the optimal iterations, all volunteers' SPARSE-SENSE images were reconstructed using 10-200 iterations, and contrast ratios, image entropies, and reconstruction times were assessed. Subsequently, the patients' SPARSE-SENSE images were reconstructed with the clinically optimal iterations. LV volumetric values were evaluated and compared between both sequences. Sufficient image quality and acceptable reconstruction times were achieved when using 80 iterations. Bland-Altman plots and Passing-Bablok regression showed good agreement for all volumetric parameters. 80 iterations are recommended for iterative SPARSE-SENSE image reconstruction in clinical routine. Real-time cine SPARSE-SENSE yielded comparable volumetric results as the current standard SSFP sequence. Due to its intrinsic low image acquisition times, real-time cine SPARSE-SENSE imaging with iterative image reconstruction seems to be an attractive alternative for LV function analysis. • A highly accelerated real-time CMR sequence using SPARSE-SENSE was evaluated. • SPARSE-SENSE allows free breathing in real-time cardiac cine imaging. • For clinically optimal SPARSE-SENSE image reconstruction, 80 iterations are recommended. • Real-time SPARSE-SENSE imaging yielded comparable volumetric results as the reference SSFP sequence. • The fast SPARSE-SENSE sequence is an attractive alternative to standard SSFP sequences.

  14. SU-E-T-335: Transit Dosimetry for Verification of Dose Delivery Using Electronic Portal Imaging Device (EPID)

    Energy Technology Data Exchange (ETDEWEB)

    Baek, T [Korea University, Seoul (Korea, Republic of); National Health Insurance Co.Ilsan Hospital, Ilsan (Korea, Republic of); Chung, E [National Health Insurance Co.Ilsan Hospital, Ilsan (Korea, Republic of); Lee, S [Cheil General Hospital and Women Healthcare Center, Kwandong University, Seoul (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

    2014-06-01

    Purpose: To evaluate the effectiveness of transit dose, measured with an electronic portal imaging device (EPID), in verifying actual dose delivery to patients. Methods: Plans of 5 patients with lung cancer, who received IMRT treatment, were examined using homogeneous solid water phantom and inhomogeneous anthropomorphic phantom. To simulate error in patient positioning, the anthropomorphic phantom was displaced from 5 mm to 10 mm in the inferior to superior (IS), superior to inferior (SI), left to right (LR), and right to left (RL) directions. The transit dose distribution was measured with EPID and was compared to the planed dose using gamma index. Results: Although the average passing rate based on gamma index (GI) with a 3% dose and a 3 mm distance-to-dose agreement tolerance limit was 94.34 % for the transit dose with homogeneous phantom, it was reduced to 84.63 % for the transit dose with inhomogeneous anthropomorphic phantom. The Result also shows that the setup error of 5mm (10mm) in IS, SI, LR and SI direction can Result in the decrease in values of GI passing rates by 1.3% (3.0%), 2.2% (4.3%), 5.9% (10.9%), and 8.9% (16.3%), respectively. Conclusion: Our feasibility study suggests that the transit dose-based quality assurance may provide information regarding accuracy of dose delivery as well as patient positioning.

  15. MO-F-CAMPUS-J-05: Using 2D Relative Gamma Analysis From EPID Image as a Predictor of Plan Deterioration Due to Anatomical Changes

    Energy Technology Data Exchange (ETDEWEB)

    Piron, O; Varfalvy, N; Archambault, L [Departement de radio-oncologie et axe oncologie du centre de recherche du CHU de Quebec, CHU de Quebec, QC (Canada); Departement de physique, genie physique et d’optique et Centre de recherche sur le cancer, Universite Laval, QC (Canada)

    2015-06-15

    Purpose: One of the side effects of radiotherapy for head and neck (H&N) cancer is the patient’s anatomical changes. The changes can strongly affect the planned dose distribution. In this work, our goal is to demonstrate that relative analysis of EPID images is a fast and simple method to detect anatomical changes that can have a strong dosimetric impact on the treatment plan for H&N patients. Methods: EPID images were recorded at every beam and all fractions for 50 H&N patients. Of these, five patients that showed important anatomical changes were selected to evaluate dosimetric impacts of these changes and to correlate them with a 2D relative gamma analysis of EPID images. The planning CT and original contours were deformed onto CBCTs (one mid treatment and one at the end of treatment). By using deformable image registration, it was possible to map accurate CT numbers from the planning CT to the anatomy of the day obtained with CBCTs. Clinical treatment plan were then copied on the deformed dataset and dose was re-computed. In parallel, EPID images were analysed using the gamma index (3%3mm) relative to the first image. Results: It was possible to divide patients in two distinct, statistically different (p<0.001) categories using an average gamma index of 0.5 as a threshold. Below this threshold no significant dosimetric degradation of the plan are observed. Above this threshold two types of plan deterioration were seen: (1) target dose increases, but coverage remains adequate while dose to at least one OAR increases beyond tolerances; (2) the OAR doses remain low, but the target dose is reduced and coverage becomes inadequate. Conclusion: Relative analysis gamma of EPID images could indeed be a fast and simple method to detect anatomical changes that can potentially deteriorates treatment plan for H&N patients. This work was supported in part by Varian Medical System.

  16. Algebraic reconstruction technique for parallel imaging reconstruction of undersampled radial data: application to cardiac cine.

    Science.gov (United States)

    Li, Shu; Chan, Cheong; Stockmann, Jason P; Tagare, Hemant; Adluru, Ganesh; Tam, Leo K; Galiana, Gigi; Constable, R Todd; Kozerke, Sebastian; Peters, Dana C

    2015-04-01

    To investigate algebraic reconstruction technique (ART) for parallel imaging reconstruction of radial data, applied to accelerated cardiac cine. A graphics processing unit (GPU)-accelerated ART reconstruction was implemented and applied to simulations, point spread functions and in 12 subjects imaged with radial cardiac cine acquisitions. Cine images were reconstructed with radial ART at multiple undersampling levels (192 Nr × Np  = 96 to 16). Images were qualitatively and quantitatively analyzed for sharpness and artifacts, and compared to filtered back-projection, and conjugate gradient SENSE. Radial ART provided reduced artifacts and mainly preserved spatial resolution, for both simulations and in vivo data. Artifacts were qualitatively and quantitatively less with ART than filtered back-projection using 48, 32, and 24 Np , although filtered back-projection provided quantitatively sharper images at undersampling levels of 48-24 Np (all P parallel radial MR imaging, providing reduced artifacts while mainly maintaining sharpness compared to filtered back-projection, as shown by its first application in cardiac studies. © 2014 Wiley Periodicals, Inc.

  17. Imaging Three-Dimensional Myocardial Mechanics Using Navigator-gated Volumetric Spiral Cine DENSE MRI

    Science.gov (United States)

    Zhong, Xiaodong; Spottiswoode, Bruce S.; Meyer, Craig H.; Kramer, Christopher M.; Epstein, Frederick H.

    2010-01-01

    A navigator-gated 3D spiral cine displacement encoding with stimulated echoes (DENSE) pulse sequence for imaging 3D myocardial mechanics was developed. In addition, previously-described 2D post-processing algorithms including phase unwrapping, tissue tracking, and strain tensor calculation for the left ventricle (LV) were extended to 3D. These 3D methods were evaluated in 5 healthy volunteers, using 2D cine DENSE and historical 3D myocardial tagging as reference standards. With an average scan time of 20.5 ± 5.7 minutes, 3D data sets with a matrix size of 128 × 128 × 22, voxel size of 2.8 × 2.8 × 5.0 mm3, and temporal resolution of 32 ms were obtained with displacement encoding in three orthogonal directions. Mean values for end-systolic mid-ventricular mid-wall radial, circumferential, and longitudinal strain were 0.33 ± 0.10, −0.17 ± 0.02, and −0.16 ± 0.02, respectively. Transmural strain gradients were detected in the radial and circumferential directions, reflecting high spatial resolution. Good agreement by linear correlation and Bland-Altman analysis was achieved when comparing normal strains measured by 2D and 3D cine DENSE. Also, the 3D strains, twist, and torsion results obtained by 3D cine DENSE were in good agreement with historical values measured by 3D myocardial tagging. PMID:20574967

  18. Right ventricular volume and mass determined by cine magnetic resonance imaging in HIV patients with possible right ventricular dysfunction

    DEFF Research Database (Denmark)

    Kjaer, Andreas; Lebech, Anne-Mette; Gerstoft, Jan

    2006-01-01

    Impaired right ventricular (RV) function has been reported to occur in patients with HIV when studied by echocardiography. However, for accurate evaluation of RV function and morphology, first-pass radionuclide ventriculography (RNV) and cine magnetic resonance imaging (cine-MRI) are methods...... ventricular ejection fraction (RVEF). To do so, we screened patients with RNV and performed an additional cine-MRI in those with reduced RVEF determined by RNV. Ninety patients with HIV were included. To evaluate the MRI measures exactly we included 18 age- and gender-matched healthy volunteers to establish...

  19. Three-dimensional cardiac cine imaging using the kat ARC acceleration: Initial experience in clinical adult patients at 3T.

    Science.gov (United States)

    Okuda, Shigeo; Yamada, Yoshitake; Tanimoto, Akihiro; Fujita, Jun; Sano, Motoaki; Fukuda, Keiichi; Kuribayashi, Sachio; Jinzaki, Masahiro; Nozaki, Atsushi; Lai, Peng

    2015-09-01

    Three-dimensional cardiac cine imaging has demonstrated promising clinical 1.5-Tesla results; however, its application to 3T scanners has been limited because of the higher sensitivity to off-resonance artifacts. The aim of this study was to apply 3D cardiac cine imaging during a single breath hold in clinical patients on a 3T scanner using the kat ARC (k- and adaptive-t auto-calibrating reconstruction for Cartesian sampling) technique and to evaluate the interchangeability between 2D and 3D cine imaging for cardiac functional analysis and detection of abnormalities in regional wall motion. Following institutional review board approval, we obtained 2D cine images with an acceleration factor of two during multiple breath holds and 3D cine images with a net scan acceleration factor of 7.7 during a single breath hold in 20 patients using a 3T unit. Two readers independently evaluated the wall motion of the left ventricle (LV) using a 5-point scale, and the consistency in the detection of regional wall motion abnormality between 2D and 3D cine was analyzed by Cohen's kappa test. The LV volume was calculated at end-diastole and end-systole (LVEDV, LVESV); the ejection fraction (LVEF) and myocardial weight (LVmass) were also calculated. The relationship between functional parameters calculated for 2D and 3D cine images was analyzed using Pearson's correlation analysis. The bias and 95% limit of agreement (LA) were calculated using Bland-Altman plots. In addition, a qualitative evaluation of image quality was performed with regard to the myocardium-blood contrast, noise level and boundary definition. Despite slight degradation in image quality for 3D cine, excellent agreement was obtained for the detection of wall motion abnormalities between 2D and 3D cine images (κ=0.84 and 0.94 for each reader). Excellent correlations between the two imaging methods were shown for the evaluation of functional parameters (r>0.97). Slight differences in LVEDV, LVESV, LVEF and LVmass

  20. Accelerated three-dimensional cine phase contrast imaging using randomly undersampled echo planar imaging with compressed sensing reconstruction.

    Science.gov (United States)

    Basha, Tamer A; Akçakaya, Mehmet; Goddu, Beth; Berg, Sophie; Nezafat, Reza

    2015-01-01

    The aim of this study was to implement and evaluate an accelerated three-dimensional (3D) cine phase contrast MRI sequence by combining a randomly sampled 3D k-space acquisition sequence with an echo planar imaging (EPI) readout. An accelerated 3D cine phase contrast MRI sequence was implemented by combining EPI readout with randomly undersampled 3D k-space data suitable for compressed sensing (CS) reconstruction. The undersampled data were then reconstructed using low-dimensional structural self-learning and thresholding (LOST). 3D phase contrast MRI was acquired in 11 healthy adults using an overall acceleration of 7 (EPI factor of 3 and CS rate of 3). For comparison, a single two-dimensional (2D) cine phase contrast scan was also performed with sensitivity encoding (SENSE) rate 2 and approximately at the level of the pulmonary artery bifurcation. The stroke volume and mean velocity in both the ascending and descending aorta were measured and compared between two sequences using Bland-Altman plots. An average scan time of 3 min and 30 s, corresponding to an acceleration rate of 7, was achieved for 3D cine phase contrast scan with one direction flow encoding, voxel size of 2 × 2 × 3 mm(3) , foot-head coverage of 6 cm and temporal resolution of 30 ms. The mean velocity and stroke volume in both the ascending and descending aorta were statistically equivalent between the proposed 3D sequence and the standard 2D cine phase contrast sequence. The combination of EPI with a randomly undersampled 3D k-space sampling sequence using LOST reconstruction allows a seven-fold reduction in scan time of 3D cine phase contrast MRI without compromising blood flow quantification. Copyright © 2014 John Wiley & Sons, Ltd.

  1. Cine magnetic resonance imaging, computed tomography and ultrasonography in the evaluation of chest wall invasion of lung cancer

    International Nuclear Information System (INIS)

    Yokozaki, Michiya; Nawano, Shigeru; Nagai, Kanji; Moriyama, Noriyuki; Kodama, Tetsuro; Nishiwaki, Yutaka.

    1997-01-01

    To assess the usefulness of cine-magnetic resonance imaging (cine-MRI) in the evaluation of chest wall invasion, we compared the results of cine-MRI with those of computed tomography (CT) and ultrasonography (US). Eleven patients were examined who had no pain and who were difficult to diagnose by routine examinations. MRI was performed with a Magnetom SP/4000, 1.5T unit (Siemens, Germany). For cine imaging, continuous turbo-FLUSH (ultra fast low angle shot) images were obtained at an orthogonal section to the chest wall during slow deep breathing. A CT scan was performed using a TCT 900S or Super Helix (Toshiba, Japan) at 1 cm intervals, with section thicknesses of 1 cm throughout the entire chest. US was performed with a model SSA-270A (Toshiba, Japan) with 7.5-MHz linear array scanners (PLF-705S; Toshiba, Japan). Sensitivity, specificity and accuracy were 67%, 75% and 73% for cine MRI, 67%, 63% and 64% for CT, 33%, 75% and 64% for US, respectively. These results indicate that cine MRI is potentially useful for the diagnosis of chest wall invasion of lung cancer. (author)

  2. Assessment of Left Ventricular Function and Mass on Free-Breathing Compressed Sensing Real-Time Cine Imaging.

    Science.gov (United States)

    Kido, Tomoyuki; Kido, Teruhito; Nakamura, Masashi; Watanabe, Kouki; Schmidt, Michaela; Forman, Christoph; Mochizuki, Teruhito

    2017-09-25

    Compressed sensing (CS) cine magnetic resonance imaging (MRI) has the advantage of being inherently insensitive to respiratory motion. This study compared the accuracy of free-breathing (FB) CS and breath-hold (BH) standard cine MRI for left ventricular (LV) volume assessment.Methods and Results:Sixty-three patients underwent cine MRI with both techniques. Both types of images were acquired in stacks of 8 short-axis slices (temporal/spatial resolution, 41 ms/1.7×1.7×6 mm 3 ) and compared for ejection fraction, end-diastolic and systolic volumes, stroke volume, and LV mass. Both BH standard and FB CS cine MRI provided acceptable image quality for LV volumetric analysis (score ≥3) in all patients (4.7±0.5 and 3.7±0.5, respectively; Pcine MRI (median, IQR: BH standard, 83.8 mL, 64.7-102.7 mL; FB CS, 79.0 mL, 66.0-101.0 mL; P=0.0006). The total acquisition times for BH standard and FB CS cine MRI were 113±7 s and 24±4 s, respectively (Pcine MRI is a clinically useful alternative to BH standard cine MRI in patients with impaired BH capacity.

  3. SU-F-T-486: A Simple Approach to Performing Light Versus Radiation Field Coincidence Quality Assurance Using An Electronic Portal Imaging Device (EPID)

    Energy Technology Data Exchange (ETDEWEB)

    Herchko, S; Ding, G [Vanderbilt University, Nashville, TN (United States)

    2016-06-15

    Purpose: To develop an accurate, straightforward, and user-independent method for performing light versus radiation field coincidence quality assurance utilizing EPID images, a simple phantom made of readily-accessible materials, and a free software program. Methods: A simple phantom consisting of a blocking tray, graph paper, and high-density wire was constructed. The phantom was used to accurately set the size of a desired light field and imaged on the electronic portal imaging device (EPID). A macro written for use in ImageJ, a free image processing software, was then use to determine the radiation field size utilizing the high density wires on the phantom for a pixel to distance calibration. The macro also performs an analysis on the measured radiation field utilizing the tolerances recommended in the AAPM Task Group #142. To verify the accuracy of this method, radiochromic film was used to qualitatively demonstrate agreement between the film and EPID results, and an additional ImageJ macro was used to quantitatively compare the radiation field sizes measured both with the EPID and film images. Results: The results of this technique were benchmarked against film measurements, which have been the gold standard for testing light versus radiation field coincidence. The agreement between this method and film measurements were within 0.5 mm. Conclusion: Due to the operator dependency associated with tracing light fields and measuring radiation fields by hand when using film, this method allows for a more accurate comparison between the light and radiation fields with minimal operator dependency. Removing the need for radiographic or radiochromic film also eliminates a reoccurring cost and increases procedural efficiency.

  4. SU-F-T-486: A Simple Approach to Performing Light Versus Radiation Field Coincidence Quality Assurance Using An Electronic Portal Imaging Device (EPID)

    International Nuclear Information System (INIS)

    Herchko, S; Ding, G

    2016-01-01

    Purpose: To develop an accurate, straightforward, and user-independent method for performing light versus radiation field coincidence quality assurance utilizing EPID images, a simple phantom made of readily-accessible materials, and a free software program. Methods: A simple phantom consisting of a blocking tray, graph paper, and high-density wire was constructed. The phantom was used to accurately set the size of a desired light field and imaged on the electronic portal imaging device (EPID). A macro written for use in ImageJ, a free image processing software, was then use to determine the radiation field size utilizing the high density wires on the phantom for a pixel to distance calibration. The macro also performs an analysis on the measured radiation field utilizing the tolerances recommended in the AAPM Task Group #142. To verify the accuracy of this method, radiochromic film was used to qualitatively demonstrate agreement between the film and EPID results, and an additional ImageJ macro was used to quantitatively compare the radiation field sizes measured both with the EPID and film images. Results: The results of this technique were benchmarked against film measurements, which have been the gold standard for testing light versus radiation field coincidence. The agreement between this method and film measurements were within 0.5 mm. Conclusion: Due to the operator dependency associated with tracing light fields and measuring radiation fields by hand when using film, this method allows for a more accurate comparison between the light and radiation fields with minimal operator dependency. Removing the need for radiographic or radiochromic film also eliminates a reoccurring cost and increases procedural efficiency.

  5. Retrospective Reconstruction of High Temporal Resolution Cine Images from Real-Time MRI using Iterative Motion Correction

    DEFF Research Database (Denmark)

    Hansen, Michael Schacht; Sørensen, Thomas Sangild; Arai, Andrew

    2012-01-01

    Cardiac function has traditionally been evaluated using breath-hold cine acquisitions. However, there is a great need for free breathing techniques in patients who have difficulty in holding their breath. Real-time cardiac MRI is a valuable alternative to the traditional breath-hold imaging...... approach, but the real-time images are often inferior in spatial and temporal resolution. This article presents a general method for reconstruction of high spatial and temporal resolution cine images from a real-time acquisition acquired over multiple cardiac cycles. The method combines parallel imaging...... and motion correction based on nonrigid registration and can be applied to arbitrary k-space trajectories. The method is demonstrated with real-time Cartesian imaging and Golden Angle radial acquisitions, and the motion-corrected acquisitions are compared with raw real-time images and breath-hold cine...

  6. Measurement of left ventricular volume by biplane cine magnetic resonance imaging in children

    Energy Technology Data Exchange (ETDEWEB)

    Ichida, Fukiko; Hamamichi, Yuuji; Hashimoto, Ikuo; Tsubata, Shinichi; Miyazaki, Ayumi; Okada, Toshio; Murakami, Arata; Futatsuya, Ryuusuke (Toyama Medical and Pharmaceutical Univ. (Japan))

    1993-09-01

    To determine the ability of cine magnetic resonance imaging (MRI) to assess left ventricular (LV) volumes, we studied 20 children (age 4 months to 10 years) with various heart disease, validated by comparison with biplane LV angiography. Previous MRI studies to assess LV volumes have used multiple axial planes, which are compromised by partial volume effects and are time consuming to acquire and analyze. Accordingly, an imaging approach using biplane cine MRI and planes aligned with the true cardiac axes (the intrinsic long and short axis) of the LV was developed in views comparable with biplane LV angiography. In all patients, LV volumes were calculated by a Simpson's rule algorithm, both in MRI and LV angiography. MRI determined LV volumes were slightly underestimated but correlated reasonably well with angiographic values (LVEDV: Y=0.88X + 1.58, R=0.98, LVESV: Y=0.72X + 1.02, R=0.98). Especially, even in the patients who have abnormal left ventricular geometry such as Tetralogy of Fallot, MRI determined LV volumes correlated well with angiographic values. It is concluded that biplane cine MRI, using the intrinsic LV long and short axis planes, permits noninvasive assessment of LV volumes in views comparable to standard angiographic projections and appears practical for clinical use in childhood heart disease, because the scan and analysis time are relatively short. (author).

  7. Measurement of left ventricular volume by biplane cine magnetic resonance imaging in children

    International Nuclear Information System (INIS)

    Ichida, Fukiko; Hamamichi, Yuuji; Hashimoto, Ikuo; Tsubata, Shinichi; Miyazaki, Ayumi; Okada, Toshio; Murakami, Arata; Futatsuya, Ryuusuke

    1993-01-01

    To determine the ability of cine magnetic resonance imaging (MRI) to assess left ventricular (LV) volumes, we studied 20 children (age 4 months to 10 years) with various heart disease, validated by comparison with biplane LV angiography. Previous MRI studies to assess LV volumes have used multiple axial planes, which are compromised by partial volume effects and are time consuming to acquire and analyze. Accordingly, an imaging approach using biplane cine MRI and planes aligned with the true cardiac axes (the intrinsic long and short axis) of the LV was developed in views comparable with biplane LV angiography. In all patients, LV volumes were calculated by a Simpson's rule algorithm, both in MRI and LV angiography. MRI determined LV volumes were slightly underestimated but correlated reasonably well with angiographic values (LVEDV: Y=0.88X + 1.58, R=0.98, LVESV: Y=0.72X + 1.02, R=0.98). Especially, even in the patients who have abnormal left ventricular geometry such as Tetralogy of Fallot, MRI determined LV volumes correlated well with angiographic values. It is concluded that biplane cine MRI, using the intrinsic LV long and short axis planes, permits noninvasive assessment of LV volumes in views comparable to standard angiographic projections and appears practical for clinical use in childhood heart disease, because the scan and analysis time are relatively short. (author)

  8. Normal nonuniformity of left ventricular contraction. Assessment by cine MR imaging with presaturation myocardial tagging

    International Nuclear Information System (INIS)

    Naito, H.; Arisawa, J.; Harada, K.; Yamagami, H.; Kozuka, T.; Tamura, S.

    1996-01-01

    Purpose: To identify the normal performance of left ventricular (LV) regional contraction using cine MR imaging with presaturation myocardial tagging. Material and Methods: Sixteen normal volunteers were examined on a 1.5 T MR system with tagging cine sequences. Tags were applied at end-diastole as 2 parallel black lines on short-axis and 4-chamber sections, and the fractional shortenings were calculated at 7 LV locations. Results: The following results were obtained with significance: A transmural gradient of contractility in the short-axis section; prolonged late-systolic endocardial shortening and epicardial early termination in the free wall; initial delay of shortening in the anterior wall; apical predominance of contractility; predominance of circumferential shortening in the free wall and of meridional shortening in the septum. These findings could be associated with myocardial fiber architecture, presumed wall stress and temporal asynergy of excitation. Conclusion: Cine MR imaging with myocardial tagging proved to be useful in assessing the nonuniformity of LV contraction. (orig.)

  9. Whole heart cine MR imaging of pulmonary veins in patients with congenital heart disease. Comparison with Spin Echo MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mitsui, Hideaki [Yamagata City Hospital Saiseikan (Japan); Saito, Haruo; Ishibashi, Tadashi; Takahashi, Shoki; Zuguchi, Masayuki; Yamada, Shogo

    2002-01-01

    We evaluated the accuracy of Whole Heart Cine (WHC) magnetic resonance (MR) imaging in the depiction of pulmonary veins (PVs) in patients with congenital heart disease (CHD) compared to that of spin echo (SE) MR imaging. Among our 35 patients, 4 patients had anomalous PV return. Detectability of four PVs on each MR examination images were evaluated. MR imaging is an effective modality for the clarification of PVs, and WHC MR imaging is more useful in delineating PV anomalies than SE MR imaging. (author)

  10. Feasibility of megavoltage portal CT using an electronic portal imaging device (EPID) and a multi-level scheme algebraic reconstruction technique (MLS-ART)

    International Nuclear Information System (INIS)

    Guan, Huaiqun; Zhu, Yunping

    1998-01-01

    Although electronic portal imaging devices (EPIDs) are efficient tools for radiation therapy verification, they only provide images of overlapped anatomic structures. We investigated using a fluorescent screen/CCD-based EPID, coupled with a novel multi-level scheme algebraic reconstruction technique (MLS-ART), for a feasibility study of portal computed tomography (CT) reconstructions. The CT images might be useful for radiation treatment planning and verification. We used an EPID, set it to work at the linear dynamic range and collimated 6 MV photons from a linear accelerator to a slit beam of 1 cm wide and 25 cm long. We performed scans under a total of ∼200 monitor units (MUs) for several phantoms in which we varied the number of projections and MUs per projection. The reconstructed images demonstrated that using the new MLS-ART technique megavoltage portal CT with a total of 200 MUs can achieve a contrast detectibility of ∼2.5% (object size 5mmx5mm) and a spatial resolution of 2.5 mm. (author)

  11. Quantification of mechanical ventricular dyssynchrony. Direct comparison of velocity-encoded and cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Muellerleile, K.; Baholli, L.; Groth, M.

    2011-01-01

    Purpose: The preoperative assessment of mechanical dyssynchrony can help to improve patient selection in candidates for cardiac resynchronization therapy (CRT). The present study compared the performance of velocity-encoded (VENC) MRI to cine-magnetic resonance imaging (MRI) for quantifying mechanical ventricular dyssynchrony. Materials and Methods: VENC-MRI and cine-MRI were performed in 20 patients with heart failure NYHA class III and reduced ejection fraction (median: 24 %, interquartile range: 18 - 28 %) before CRT device implantation. The interventricular mechanical delay (IVMD) was assessed by VENC-MRI as the temporal difference between the onset of aortic and pulmonary flow. Intraventricular dyssynchrony was quantified by cine-MRI, using the standard deviation of time to maximal wall thickening in sixteen left ventricular segments (SDt-16). The response to CRT was assessed in a six-month follow-up. Results: 14 patients (70 %) clinically responded to CRT. A similar accuracy was found to predict the response to CRT by measurements of the IVMD and SDt-16 (75 vs. 70 %; p = ns). The time needed for data analysis was significantly shorter for the IVMD at 1.69 min (interquartile range: 1.66 - 1.88 min) compared to 9.63 min (interquartile range: 8.92 - 11.63 min) for the SDt-16 (p < 0.0001). Conclusion: Measurements of the IVMD by VENC-MRI and the SDt-16 by cine-MRI provide a similar accuracy to identify clinical responders to CRT. However, data analysis of the IVMD is significantly less time-consuming compared to data analysis of the SDt-16. (orig.)

  12. Development of automatic extraction method of left ventricular contours on long axis view MR cine images

    International Nuclear Information System (INIS)

    Utsunomiya, Shinichi; Iijima, Naoto; Yamasaki, Kazunari; Fujita, Akinori

    1995-01-01

    In the MRI cardiac function analysis, left ventricular volume curves and diagnosis parameters are obtained by extracting the left ventricular cavities as regions of interest (ROI) from long axis view MR cine images. The ROI extractions had to be done by manual operations, because automatization of the extraction is difficult. A long axis view left ventricular contour consists of a cardiac wall part and an aortic valve part. The above mentioned difficulty is due to the decline of contrast on the cardiac wall part, and the disappearance of edge on the aortic valve part. In this paper, we report a new automatic extraction method for long axis view MR cine images, which needs only 3 manually indicated points on the 1st image to extract all the contours from the total sequence of images. At first, candidate points of a contour are detected by edge detection. Then, selecting the best matched combination of candidate points by Dynamic Programming, the cardiac wall part is automatically extracted. The aortic valve part is manually extracted for the 1st image by indicating both the end points, and is automatically extracted for the rest of the images, by utilizing the aortic valve motion characteristics throughout a cardiac cycle. (author)

  13. Standardized cine-loop documentation in abdominal ultrasound facilitates offline image interpretation.

    Science.gov (United States)

    Dormagen, Johann Baptist; Gaarder, Mario; Drolsum, Anders

    2015-01-01

    One of the main disadvantages of conventional ultrasound is its operator dependency, which might impede the reproducibility of the sonographic findings. A new approach with cine-loops and standardized scan protocols can overcome this drawback. To compare abdominal ultrasound findings of immediate bedside reading by performing radiologist with offline reading by a non-performing radiologist, using standardized cine-loop sequences. Over a 6-month period, three radiologists performed 140 dynamic ultrasound organ-based examinations in 43 consecutive outpatients. Examination protocols were standardized and included predefined probe position and sequences of short cine-loops of the liver, gallbladder, pancreas, kidneys, and urine bladder, covering the organs completely in two planes. After bedside examinations, the studies were reviewed and read out immediately by the performing radiologist. Image quality was registered from 1 (no diagnostic value) to 5 (excellent cine-loop quality). Offline reading was performed blinded by a radiologist who had not performed the examination. Bedside and offline reading were compared with each other and with consensus results. In 140 examinations, consensus reading revealed 21 cases with renal disorders, 17 cases with liver and bile pathology, and four cases with bladder pathology. Overall inter-observer agreement was 0.73 (95% CI 0.61-0.91), with lowest agreement for findings of the urine bladder (0.36) and highest agreement in liver examinations (0.90). Disagreements between the two readings were seen in nine kidneys, three bladder examinations, one pancreas and bile system examinations each, and in one liver, giving a total number of mismatches of 11%. Nearly all cases of mismatch were of minor clinical significance. The median image quality was 3 (range, 2-5) with most examinations deemed a quality of 3. Compared to consensus reading, overall accuracy was 96% for bedside reading and 94% for offline reading. Standardized cine

  14. Fetal cardiac cine imaging using highly accelerated dynamic MRI with retrospective motion correction and outlier rejection.

    Science.gov (United States)

    van Amerom, Joshua F P; Lloyd, David F A; Price, Anthony N; Kuklisova Murgasova, Maria; Aljabar, Paul; Malik, Shaihan J; Lohezic, Maelene; Rutherford, Mary A; Pushparajah, Kuberan; Razavi, Reza; Hajnal, Joseph V

    2018-01-01

    Development of a MRI acquisition and reconstruction strategy to depict fetal cardiac anatomy in the presence of maternal and fetal motion. The proposed strategy involves i) acquisition and reconstruction of highly accelerated dynamic MRI, followed by image-based ii) cardiac synchronization, iii) motion correction, iv) outlier rejection, and finally v) cardiac cine reconstruction. Postprocessing entirely was automated, aside from a user-defined region of interest delineating the fetal heart. The method was evaluated in 30 mid- to late gestational age singleton pregnancies scanned without maternal breath-hold. The combination of complementary acquisition/reconstruction and correction/rejection steps in the pipeline served to improve the quality of the reconstructed 2D cine images, resulting in increased visibility of small, dynamic anatomical features. Artifact-free cine images successfully were produced in 36 of 39 acquired data sets; prolonged general fetal movements precluded processing of the remaining three data sets. The proposed method shows promise as a motion-tolerant framework to enable further detail in MRI studies of the fetal heart and great vessels. Processing data in image-space allowed for spatial and temporal operations to be applied to the fetal heart in isolation, separate from extraneous changes elsewhere in the field of view. Magn Reson Med 79:327-338, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  15. Accuracy of accelerated cine MR imaging at 3 Tesla in longitudinal follow-up of cardiac function

    International Nuclear Information System (INIS)

    Sandner, Torleif A.; Huber, Armin M.; Theisen, Daniel; Reiser, Maximilian F.; Wintersperger, Bernd J.; Houck, Philip; Runge, Val M.; Sincleair, Spencer

    2008-01-01

    The ability of fast, parallel-imaging-based cine magnetic resonance (MR) to monitor global cardiac function in longitudinal exams at 3 Tesla was evaluated. Seventeen patients with chronic cardiac disease underwent serial cine MR imaging exams (n=3) at 3 Tesla. Data were acquired in short-axis orientation using cine steady-state free precession (SSFP) with a spatial resolution of 2.5 x 1.9 mm 2 at 45 ms temporal resolution. Multislice imaging (three slices/breath-hold) was performed using TSENSE acceleration (R=3) and standard single-slice cine (non-TSENSE) was performed at identical locations in consecutive breath-holds. End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and myocardial mass (MM) of both cine approaches were compared for individual time-points as well as for longitudinal comparison. TSENSE-cine did not show significant differences for EDV (2.6 ml; P=.79), ESV (2.2 ml; P=0.81), EF (-0.3%; P=0.95) and MM (2.4 g; P=0.72) in comparison with non-TSENSE. Longitudinal ANOVA analysis did not reveal significant differences for any parameter, neither for non-TSENSE data (all P>0.7) nor for TSENSE data (all P>0.9). Multifactorial ANOVA showed non-significant differences (all P>0.7) at comparable data variances. Data acquisition was significantly shortened using TSENSE. Threefold accelerated multislice cine at 3 Tesla allows accurate assessment of volumetric LV data and accurate longitudinal monitoring of global LV function at a substantially shorter overall examination time. (orig.)

  16. Real-time automatic fiducial marker tracking in low contrast cine-MV images

    International Nuclear Information System (INIS)

    Lin, Wei-Yang; Lin, Shu-Fang; Yang, Sheng-Chang; Liou, Shu-Cheng; Nath, Ravinder; Liu Wu

    2013-01-01

    Purpose: To develop a real-time automatic method for tracking implanted radiographic markers in low-contrast cine-MV patient images used in image-guided radiation therapy (IGRT). Methods: Intrafraction motion tracking using radiotherapy beam-line MV images have gained some attention recently in IGRT because no additional imaging dose is introduced. However, MV images have much lower contrast than kV images, therefore a robust and automatic algorithm for marker detection in MV images is a prerequisite. Previous marker detection methods are all based on template matching or its derivatives. Template matching needs to match object shape that changes significantly for different implantation and projection angle. While these methods require a large number of templates to cover various situations, they are often forced to use a smaller number of templates to reduce the computation load because their methods all require exhaustive search in the region of interest. The authors solve this problem by synergetic use of modern but well-tested computer vision and artificial intelligence techniques; specifically the authors detect implanted markers utilizing discriminant analysis for initialization and use mean-shift feature space analysis for sequential tracking. This novel approach avoids exhaustive search by exploiting the temporal correlation between consecutive frames and makes it possible to perform more sophisticated detection at the beginning to improve the accuracy, followed by ultrafast sequential tracking after the initialization. The method was evaluated and validated using 1149 cine-MV images from two prostate IGRT patients and compared with manual marker detection results from six researchers. The average of the manual detection results is considered as the ground truth for comparisons. Results: The average root-mean-square errors of our real-time automatic tracking method from the ground truth are 1.9 and 2.1 pixels for the two patients (0.26 mm/pixel). The

  17. Cine Magnetic Resonance Imaging of the Small Bowel: Comparison of Different Oral Contrast Media

    Energy Technology Data Exchange (ETDEWEB)

    Asbach, P.; Breitwieser, C.; Diederichs, G.; Eisele, S.; Kivelitz, D.; Taupitz, M.; Zeitz, M.; Hamm, B.; Klessen, C. [Charite - Universitatsmedizin Berlin, Charite Campus Mitte, Berlin (Germany). Dept. of Radiology

    2006-11-15

    Purpose: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. Material and Methods: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. Results: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. Conclusion: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences.

  18. Cine Magnetic Resonance Imaging of the Small Bowel: Comparison of Different Oral Contrast Media

    International Nuclear Information System (INIS)

    Asbach, P.; Breitwieser, C.; Diederichs, G.; Eisele, S.; Kivelitz, D.; Taupitz, M.; Zeitz, M.; Hamm, B.; Klessen, C.

    2006-01-01

    Purpose: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. Material and Methods: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. Results: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. Conclusion: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences

  19. Fully automated segmentation of left ventricle using dual dynamic programming in cardiac cine MR images

    Science.gov (United States)

    Jiang, Luan; Ling, Shan; Li, Qiang

    2016-03-01

    Cardiovascular diseases are becoming a leading cause of death all over the world. The cardiac function could be evaluated by global and regional parameters of left ventricle (LV) of the heart. The purpose of this study is to develop and evaluate a fully automated scheme for segmentation of LV in short axis cardiac cine MR images. Our fully automated method consists of three major steps, i.e., LV localization, LV segmentation at end-diastolic phase, and LV segmentation propagation to the other phases. First, the maximum intensity projection image along the time phases of the midventricular slice, located at the center of the image, was calculated to locate the region of interest of LV. Based on the mean intensity of the roughly segmented blood pool in the midventricular slice at each phase, end-diastolic (ED) and end-systolic (ES) phases were determined. Second, the endocardial and epicardial boundaries of LV of each slice at ED phase were synchronously delineated by use of a dual dynamic programming technique. The external costs of the endocardial and epicardial boundaries were defined with the gradient values obtained from the original and enhanced images, respectively. Finally, with the advantages of the continuity of the boundaries of LV across adjacent phases, we propagated the LV segmentation from the ED phase to the other phases by use of dual dynamic programming technique. The preliminary results on 9 clinical cardiac cine MR cases show that the proposed method can obtain accurate segmentation of LV based on subjective evaluation.

  20. Application of cine cardiac MR imaging in normal subjects and patients with valvular, coronary artery, and aortic disease

    International Nuclear Information System (INIS)

    Maddahi, J.; Ostrzega, E.; Crues, J.; Honma, H.; Siegel, R.; Charuzi, Y.; Berman, D.

    1987-01-01

    Cine MR imaging was performed on 15 normal subjects and 27 patients with cardiac disease. In normal subjects, high signal intensity of flowing blood contrasted with that of the myocardium. In 16 patients with valvular regurgitation, signal void jet due to turbulence was visualized across the diseased valves. In three IHSS patients, thickened LV myocardium, mitral regurgitant jets, and systolic LV outflow jets were noted. Five patients with myocardial infarction (MI) showed thinning and/or hypokinesis of MI regions. In three patients with Marfan syndrome, aortic dilatation, insufficiency, and flap (one pt) were identified. Cine MR imaging is potentially useful for evaluation of a variety of cardiac diseases

  1. Texture analysis of cardiac cine magnetic resonance imaging to detect nonviable segments in patients with chronic myocardial infarction.

    Science.gov (United States)

    Larroza, Andrés; López-Lereu, María P; Monmeneu, José V; Gavara, Jose; Chorro, Francisco J; Bodí, Vicente; Moratal, David

    2018-04-01

    To investigate the ability of texture analysis to differentiate between infarcted nonviable, viable, and remote segments on cardiac cine magnetic resonance imaging (MRI). This retrospective study included 50 patients suffering chronic myocardial infarction. The data were randomly split into training (30 patients) and testing (20 patients) sets. The left ventricular myocardium was segmented according to the 17-segment model in both cine and late gadolinium enhancement (LGE) MRI. Infarcted myocardium regions were identified on LGE in short-axis views. Nonviable segments were identified as those showing LGE ≥ 50%, and viable segments those showing 0 cine images. A support vector machine (SVM) classifier was trained with different combination of texture features to obtain a model that provided optimal classification performance. The best classification on testing set was achieved with local binary patterns features using a 2D + t approach, in which the features are computed by including information of the time dimension available in cine sequences. The best overall area under the receiver operating characteristic curve (AUC) were: 0.849, sensitivity of 92% to detect nonviable segments, 72% to detect viable segments, and 85% to detect remote segments. Nonviable segments can be detected on cine MRI using texture analysis and this may be used as hypothesis for future research aiming to detect the infarcted myocardium by means of a gadolinium-free approach. © 2018 American Association of Physicists in Medicine.

  2. Left-ventricular reduction surgery: pre- and postoperative evaluation by cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Kivelitz, D.E.; Enzweiler, C.N.H.; Wiese, T.H.; Lembcke, A.; Hamm, B.; Hotz, H.; Konertz, W.; Borges, A.C.; Baumann, G.

    2001-01-01

    Aim: To evaluate the role of cine magnetic resonance imaging (MRI) in the preoperative assessment and postoperative follow-up of patients undergoing left ventricular (LV) reduction surgery. Patients and Methods: 6 patients with cardiomegaly were examined on a 1.5 T MR imager before and after LV reduction surgery. The heart was imaged along the short and long axes using a breath-hold ECG-triggered cine gradient-echo sequence for assessing ventricular and valvular morphology and function and performing volumetry (end-diastolic and end-systolic volumes, ejection fraction). Results: Postoperatively, the mean ejection fraction increased from 21.7% to 33.4% and the enddiastolic and end-systolic left ventricular volumes decreased in all patients (304.0 and 252.5 ml before to 205.0 and 141.9 ml after surgery). Mean myocardial mass decreased slightly from 283.8 g to 242.7 g. Differences were significant for all parameters (p [de

  3. Development of ultrasound/endoscopy PACS (picture archiving and communication system) and investigation of compression method for cine images

    Science.gov (United States)

    Osada, Masakazu; Tsukui, Hideki

    2002-09-01

    ABSTRACT Picture Archiving and Communication System (PACS) is a system which connects imaging modalities, image archives, and image workstations to reduce film handling cost and improve hospital workflow. Handling diagnostic ultrasound and endoscopy images is challenging, because it produces large amount of data such as motion (cine) images of 30 frames per second, 640 x 480 in resolution, with 24-bit color. Also, it requires enough image quality for clinical review. We have developed PACS which is able to manage ultrasound and endoscopy cine images with above resolution and frame rate, and investigate suitable compression method and compression rate for clinical image review. Results show that clinicians require capability for frame-by-frame forward and backward review of cine images because they carefully look through motion images to find certain color patterns which may appear in one frame. In order to satisfy this quality, we have chosen motion JPEG, installed and confirmed that we could capture this specific pattern. As for acceptable image compression rate, we have performed subjective evaluation. No subjects could tell the difference between original non-compressed images and 1:10 lossy compressed JPEG images. One subject could tell the difference between original and 1:20 lossy compressed JPEG images although it is acceptable. Thus, ratios of 1:10 to 1:20 are acceptable to reduce data amount and cost while maintaining quality for clinical review.

  4. Functional cine MR imaging for the detection and mapping of intraabdominal adhesions: method and surgical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Buhmann-Kirchhoff, Sonja; Reiser, Maximilian; Lienemann, Andreas [University Hospital Grosshadern, Ludwig-Maximilians-University Munich, Department of Clinical Radiology, Munich (Germany); Lang, Reinhold; Steitz, Heinrich O.; Jauch, Karl W. [University Hospital Munich-Grosshadern, Department of Surgery, Munich (Germany); Kirchhoff, Chlodwig [University Hospital Munich-Innenstadt, Department of Surgery, Munich (Germany)

    2008-06-15

    The purpose of this study was to evaluate the presence and localization of intraabdominal adhesions using functional cine magnetic resonance imaging (MRI) and to correlate the MR findings with intraoperative results. In a retrospective study, patients who had undergone previous abdominal surgery with suspected intraabdominal adhesions were examined. A true fast imaging with steady state precession sequence in transverse/sagittal orientation was used for a section-by-section dynamic depiction of visceral slide on a 1.5-Tesla system. After MRI, all patients underwent anew surgery. A nine-segment abdominal map was used to document the location and type of the adhesions. The intraoperative results were taken as standard of reference. Ninety patients were enrolled. During surgery 71 adhesions were detected, MRI depicted 68 intraabdominal adhesions. The most common type of adhesion in MRI was found between the anterior abdominal wall and small bowel loops (n = 22, 32.5%) and between small bowel loops and pelvic organs (n = 14, 20.6%). Comparing MRI with the intraoperative findings, sensitivity varied between 31 and 75% with a varying specificity between 65 and 92% in the different segments leading to an overall MRI accuracy of 89%. Functional cine MRI proved to be a useful examination technique for the identification of intraabdominal adhesions in patients with acute or chronic pain and corresponding clinical findings providing accurate results. However, no differentiation for symptomatic versus asymptomatic adhesions is possible. (orig.)

  5. Evaluation of cardiac dyssynchrony with longitudinal strain analysis in 4-chamber cine MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kawakubo, Masateru, E-mail: masateru@med.kyushu-u.ac.jp [Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Nagao, Michinobu, E-mail: minagao@radiol.med.kyushu-u.ac.jp [Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Kumazawa, Seiji, E-mail: s_kmzw@hs.med.kyushu-u.ac.jp [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Chishaki, Akiko S., E-mail: chishaki@hs.med.kyushu-u.ac.jp [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Mukai, Yasushi, E-mail: y_mukai@cardiol.med.kyushu-u.ac.jp [Department of Cardiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Nakamura, Yasuhiko, E-mail: yas-nkmr@r-tec.med.kyushu-u.ac.jp [Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Honda, Hiroshi, E-mail: honda@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Morishita, Junji, E-mail: junjim@med.kyushu-u.ac.jp [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan)

    2013-12-01

    Purpose: We investigated the clinical performance of evaluation of cardiac mechanical dyssynchrony with longitudinal strain analysis using four-chamber (4CH) cine magnetic resonance imaging (MRI). Materials and methods: We retrospectively enrolled 73 chronic heart failure patients (41 men, 32 women; mean age, 57 years, NYHA 2, 3, and 4) who underwent a cardiac MRI in the present study. The left ventricular dyssynchrony (LVD) and interventricular dyssynchrony (IVD) indices were calculated by longitudinal strain analysis using 4CH cine MRI. The LVD and IVD indices were compared by the Wilcoxon rank-sum test between the patients with indication for cardiac resynchronization therapy (CRT) (n = 13) and without indication for CRT (n = 60), with LGE (n = 40) and without LGE (n = 27), the CRT responders (n = 8) and non-responders (n = 6), respectively. Results: LVD in the patients with indication for CRT were significantly longer than those without indication for CRT (LVD: 92 ± 65 vs. 28 ± 40 ms, P < .01). LVD and IVD were significantly longer in the patients with LGE than those without LGE (LVD: 54 ± 58 vs. 21 ± 30 ms, P < .01 and IVD: 51 ± 39 vs. 23 ± 34 ms, P < .01). LVD and IVD in the CRT responders were significantly longer than the CRT non-responders (LVD: 126 ± 55 vs. 62 ± 55 ms, P < .01 and IVD: 96 ± 39 vs. 52 ± 40 ms, P < .05). Conclusion: Longitudinal strain analysis with 4CH cine MRI could be useful for clinical examination in the evaluation of cardiac mechanical dyssynchrony.

  6. Cine MRI of dissecting aneurysm

    International Nuclear Information System (INIS)

    Takaki, Hajime

    1991-01-01

    Cine MRI was performed in 25 cases of aortic dissection and comparative study among cine MRI, spin-echo static MRI, contrast-enhanced CT and intravenous digital subtraction angiography (IVDSA) was made. Cine MRI accurately detected aortic dissection. It was most accurate among various diagnostic methods in demonstration of entry site of dissection. Take-off of renal artery and its relation to true and false channels was also accurately demonstrated by cine MRI. The above results suggest that cine MRI can be an important diagnostic modality with almost equal diagnostic quality to those of conventional angiography. However, further technical improvement to shorten the imaging time seems necessary to replace angiography. (author)

  7. Area detection of uterine peristalsis using cine-MR images

    International Nuclear Information System (INIS)

    Sato, Tetsuo; Fujita, Nao; Nakai, Asako; Togashi, Kaori; Kuhara, Shigehide; Okada, Tomohisa

    2011-01-01

    In this paper, a technique for evaluating uterine peristalsis obtained by magnetic resonance images is proposed. Uterine peristalsis is the wavelike movement of uterine muscle contractions with rhythm and direction. Correlation between direction of uterine peristalsis and menstrual cycle has been reported, which is supposed to help sperm transpotation and implantation. While evaluation of uterine peristalsis has been done, they are very subjective and no quantitative evaluation has been established. In the proposed method the peristalsis area and their contraction intensity were calculated. The points of uterine peristalsis was estimated by the spatio-temporal map, which reflect the time series behavior of the intensities around points set on uterine endometrial boundaries. Then peristalsis area was decided as the estimated points. The contraction intensity was defined as the ratio of the signal intensity change in the peristalsis area. (author)

  8. Comparative assessment of liver tumor motion using cine-magnetic resonance imaging versus 4-dimensional computed tomography.

    Science.gov (United States)

    Fernandes, Annemarie T; Apisarnthanarax, Smith; Yin, Lingshu; Zou, Wei; Rosen, Mark; Plastaras, John P; Ben-Josef, Edgar; Metz, James M; Teo, Boon-Keng

    2015-04-01

    To compare the extent of tumor motion between 4-dimensional CT (4DCT) and cine-MRI in patients with hepatic tumors treated with radiation therapy. Patients with liver tumors who underwent 4DCT and 2-dimensional biplanar cine-MRI scans during simulation were retrospectively reviewed to determine the extent of target motion in the superior-inferior, anterior-posterior, and lateral directions. Cine-MRI was performed over 5 minutes. Tumor motion from MRI was determined by tracking the centroid of the gross tumor volume using deformable image registration. Motion estimates from 4DCT were performed by evaluation of the fiducial, residual contrast (or liver contour) positions in each CT phase. Sixteen patients with hepatocellular carcinoma (n=11), cholangiocarcinoma (n=3), and liver metastasis (n=2) were reviewed. Cine-MRI motion was larger than 4DCT for the superior-inferior direction in 50% of patients by a median of 3.0 mm (range, 1.5-7 mm), the anterior-posterior direction in 44% of patients by a median of 2.5 mm (range, 1-5.5 mm), and laterally in 63% of patients by a median of 1.1 mm (range, 0.2-4.5 mm). Cine-MRI frequently detects larger differences in hepatic intrafraction tumor motion when compared with 4DCT most notably in the superior-inferior direction, and may be useful when assessing the need for or treating without respiratory management, particularly in patients with unreliable 4DCT imaging. Margins wider than the internal target volume as defined by 4DCT were required to encompass nearly all the motion detected by cine-MRI for some of the patients in this study. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. [Value of cine magnetic resonance imaging in the diagnosis and quantification of valvular regurgitation. Comparison with angiography and Doppler echocardiography].

    Science.gov (United States)

    Germain, P; Baruthio, J; Roul, G; Mossard, J M; Bareiss, P; Wecker, D; Chambron, J; Sacrez, A

    1989-10-01

    Thirty-three patients presenting with regurgitation of the mitral valve (19 cases), tricuspid valve (14 cases) or aortic valve (11 cases) documented by angiography (n = 20) and/or doppler-echocardiography (n = 28) were examined by cine-MRI in order to test this method in valvular regurgitation. Sixteen ECG-synchronized cine-MRI images were acquired by the GRASS technique every 40 ms on appropriate projections, with a resistive 0.28 Tesla Bruker magnet. The semiology of normal and pathological blood flow images at cine-MRI is described. Valvular regurgitations present as "signal void" jets the chronology and spatial extension of which depend on the severity of the lesion. The differential diagnosis with physiological flows is discussed. The diagnostic sensitivity of the method was 29/29 when compared with angiography and 29/33 when compared with doppler-echocardiography (2 cases of 1/4 mitral regurgitation and 2 cases 1/4 tricuspid regurgitation were not visible at cine-MRI). The specificity of this method, as can be judged from 104 patients explored, also seems to be satisfactory. The severity of regurgitation was graded from 1 to 4 with the three methods, on the basis of strict criteria. The differences in grade evaluation exceeded +/- 1 point in only one case of mitral regurgitation which was greatly underestimated by the doppler method as compared with angiography and cine-MRI. Thus, cine-MRI is a reliable method to evaluate valvular regurgitations and their severity. It solves the practical problem raised by non-echogenic patients when catheterization is to be postponed or avoided.

  10. A four-dimensional motion field atlas of the tongue from tagged and cine magnetic resonance imaging

    Science.gov (United States)

    Xing, Fangxu; Prince, Jerry L.; Stone, Maureen; Wedeen, Van J.; El Fakhri, Georges; Woo, Jonghye

    2017-02-01

    Representation of human tongue motion using three-dimensional vector fields over time can be used to better understand tongue function during speech, swallowing, and other lingual behaviors. To characterize the inter-subject variability of the tongue's shape and motion of a population carrying out one of these functions it is desirable to build a statistical model of the four-dimensional (4D) tongue. In this paper, we propose a method to construct a spatio-temporal atlas of tongue motion using magnetic resonance (MR) images acquired from fourteen healthy human subjects. First, cine MR images revealing the anatomical features of the tongue are used to construct a 4D intensity image atlas. Second, tagged MR images acquired to capture internal motion are used to compute a dense motion field at each time frame using a phase-based motion tracking method. Third, motion fields from each subject are pulled back to the cine atlas space using the deformation fields computed during the cine atlas construction. Finally, a spatio-temporal motion field atlas is created to show a sequence of mean motion fields and their inter-subject variation. The quality of the atlas was evaluated by deforming cine images in the atlas space. Comparison between deformed and original cine images showed high correspondence. The proposed method provides a quantitative representation to observe the commonality and variability of the tongue motion field for the first time, and shows potential in evaluation of common properties such as strains and other tensors based on motion fields.

  11. MR imaging of the pulmonary vasculature: Cine and high-resolution techniques

    International Nuclear Information System (INIS)

    Gefter, W.B.; Hatabu, H.; Kressel, H.Y.; Axel, L.; Lenkinski, R.E.; Schiebler, M.L.; Dougherty, L.; Douglas, P.S.; Reichek, N.

    1987-01-01

    Pulmonary vessels were evaluated on 43 cine examinations (12 normals, 31 with cardiopulmonary diseases) at 1.5 T (General Electric). Arteries and veins could be differentiated by characteristic intensity fluctuations in 90%. Abnormal patterns were observed with elevated left atrial pressure, pulmonary hypertension, pulmonic stenosis, and mitral regurgitation. A small arteriovenous malformation was identified. Approaches to high-resolution imaging included surface coils, 24-cm field of view, and 256 x 256 matrix. Spin-echo (SE) sequences gated in systole or diastole, and GRASS with and without breath-holding were evaluated. Surface-coil SE diastolic images (4 NEX) visualized sixth- and seventh-generation vessels. Breath-hold GRASS showed fifth- and sixth-generation vessels without respiratory artifact. These are promising techniques for displaying the pulmonary circulation

  12. Uterine contractions evaluated on cine MR imaging in patients with uterine leiomyomas

    Energy Technology Data Exchange (ETDEWEB)

    Nishino, Mizuki E-mail: mizuki@mbox.kyoto-inet.or.jpnishinomizuki@hotmail.com; Togashi, Kaori; Nakai, Asako; Hayakawa, Katsumi; Kanao, Shotarou; Iwasaku, Kazuhiro; Fujii, Shingo

    2005-01-01

    Purpose: Submucosal leiomyoma is one of the most recognized causes of infertility and habitual abortion. The purpose of this study is to evaluate uterine peristalsis, a cycle-related inherent contractility of uterus probably responsible for sperm transport and conservation of pregnancy, in patients with uterine leiomyomas using cine magnetic resonance (MR) imaging. Materials and methods: Study population consisted of 26 female patients (age range: 19-51 years, mean: 41 years), in which 16 patients had submucosal leiomyomas and 10 patients had intramural or subserosal leiomyomas. We prospectively performed MR imaging of the midsagittal plane of uterus using 1.5 T magnet (Symphony, Siemens Medical Systems) with a body array coil, and obtained 60 half-Fourier acquisition single shot turbo spin echo (HASTE) images (Echo time=80 ms, FOV=300 mm, slice thickness 5 mm, matrix 256x256) within 2 min, and displayed them on cine mode at 12x faster than real speed. Evaluated were peristaltic movements at the endometral-myometrial junction and focal myometrial movements, adjacent to leiomyomas, regarding presence, direction, frequency, and conduction. Results: The peristaltic movements were identified in 12/16 patients with submucosal lesions and 10/10 with other leiomyomas. The frequency and direction were cycle-related. Loss of peristalsis was noted adjacent to submucosal myomas in 4/12 patients, but was not in others. Focal myometrial movements were noted in 9/16 patients with submucosal myomas, but not in others. Conclusions: Uterine peristaltic movements were partly interrupted by submucosal leiomoymas, but not by myometrial or subserosal leiomyomas. Loss of peristalsis and focal myometrial movements was noted only adjacent to submucosal leiomyomas. These findings are considered to represent dysfunctional contractility, and may be related with pregnancy loss.

  13. Uterine contractions evaluated on cine MR imaging in patients with uterine leiomyomas

    International Nuclear Information System (INIS)

    Nishino, Mizuki; Togashi, Kaori; Nakai, Asako; Hayakawa, Katsumi; Kanao, Shotarou; Iwasaku, Kazuhiro; Fujii, Shingo

    2005-01-01

    Purpose: Submucosal leiomyoma is one of the most recognized causes of infertility and habitual abortion. The purpose of this study is to evaluate uterine peristalsis, a cycle-related inherent contractility of uterus probably responsible for sperm transport and conservation of pregnancy, in patients with uterine leiomyomas using cine magnetic resonance (MR) imaging. Materials and methods: Study population consisted of 26 female patients (age range: 19-51 years, mean: 41 years), in which 16 patients had submucosal leiomyomas and 10 patients had intramural or subserosal leiomyomas. We prospectively performed MR imaging of the midsagittal plane of uterus using 1.5 T magnet (Symphony, Siemens Medical Systems) with a body array coil, and obtained 60 half-Fourier acquisition single shot turbo spin echo (HASTE) images (Echo time=80 ms, FOV=300 mm, slice thickness 5 mm, matrix 256x256) within 2 min, and displayed them on cine mode at 12x faster than real speed. Evaluated were peristaltic movements at the endometral-myometrial junction and focal myometrial movements, adjacent to leiomyomas, regarding presence, direction, frequency, and conduction. Results: The peristaltic movements were identified in 12/16 patients with submucosal lesions and 10/10 with other leiomyomas. The frequency and direction were cycle-related. Loss of peristalsis was noted adjacent to submucosal myomas in 4/12 patients, but was not in others. Focal myometrial movements were noted in 9/16 patients with submucosal myomas, but not in others. Conclusions: Uterine peristaltic movements were partly interrupted by submucosal leiomoymas, but not by myometrial or subserosal leiomyomas. Loss of peristalsis and focal myometrial movements was noted only adjacent to submucosal leiomyomas. These findings are considered to represent dysfunctional contractility, and may be related with pregnancy loss

  14. Spirometer-controlled cine magnetic resonance imaging to diagnose tracheobronchomalacia in pediatric patients

    DEFF Research Database (Denmark)

    Ciet, Pierluigi; Wielopolski, Piotr; Manniesing, Rashindra

    2014-01-01

    Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard to diagnose TBM, but bronchoscopy has major disadvantages, such as general anaesthesia. Cine-CT is a non-invasive alternative to diagnose TBM, but its use in children...... is restricted by ionizing radiation. Our aim was to evaluate the feasibility of spirometer-controlled cine-MRI as alternative to cine-CT in a retrospective study.12 children (mean 12 years, range 7-17), suspected to have TBM, underwent cine-MRI. Static scans were acquired at end-inspiration and expiration...... covering the thorax using a 3D SPGR sequence. 3D-Dynamic-scans were performed covering only the central airways. TBM was defined as a decrease of the trachea or bronchi diameter greater than 50% at end-expiration in the static and dynamic scans.The success rate of the cine-MRI protocol was 92%. Cine...

  15. Interpretation of cardiac wall motion from cine-MRI combined with parametric imaging based on the Hilbert transform.

    Science.gov (United States)

    Benameur, Narjes; Caiani, Enrico Gianluca; Arous, Younes; Abdallah, Nejmeddine Ben; Kraiem, Tarek

    2017-08-01

    The aim of this study was to test and validate the clinical impact of parametric amplitude images obtained using the Hilbert transform on the regional interpretation of cardiac wall motion abnormalities from cine-MR images by non-expert radiologists compared with expert consensus. Cine-MRI short-axis images obtained in 20 patients (10 with myocardial infarction, 5 with myocarditis and 5 with normal function) were processed to compute a parametric amplitude image for each using the Hilbert transform. Two expert radiologists blindly reviewed the cine-MR images to define a gold standard for wall motion interpretation for each left ventricular sector. Two non-expert radiologists reviewed and graded the same images without and in combination with parametric images. Grades assigned to each segment in the two separate sessions were compared with the gold standard. According to expert interpretation, 264/320 (82.5%) segments were classified as normal and 56/320 (17.5%) were considered abnormal. The accuracy of the non-expert radiologists' grades compared to the gold standard was significantly improved by adding parametric images (from 87.2 to 94.6%) together with sensitivity (from 64.29 to 84.4%) and specificity (from 92 to 96.9%), also resulting in reduced interobserver variability (from 12.8 to 5.6%). The use of parametric amplitude images based on the Hilbert transform in conjunction with cine-MRI was shown to be a promising technique for improvement of the detection of left ventricular wall motion abnormalities in less expert radiologists.

  16. Cine MR imaging assessment of regional left ventricular systolic wall thickening in patients with remote myocardial infarction

    International Nuclear Information System (INIS)

    Pfugfelder, P.; White, R.D.; Sechtem, U.; Gould, R.G.; Higgins, C.B.

    1986-01-01

    Cine MR imaging, a new rapid imaging technique, was used to acquire transverse images of the heart at a rate of 16-30 frames per cardiac cycle. Left ventricular wall thickness was measured at end diastole and end systole in six regions in the midventricular section of 13 healthy subjects and seven patients with previously documented myocardial infarction. Mean percent systolic wall thickening (%SWT) was 51% +- 26% in healthy subjects. In patients, %SWT was -8% +- 22% in the infarct zone and 42% +- 22% in the normal myocardium. In addition to the qualitative information derived from the cinematic display, determination of regional %SWT by cine-MR imaging may be useful for quantifying regional left ventricular dysfunction

  17. Evaluation of a motion artifacts removal approach on breath-hold cine-magnetic resonance images of hypertrophic cardiomyopathy subjects

    Science.gov (United States)

    Betancur, Julián.; Simon, Antoine; Schnell, Frédéric; Donal, Erwan; Hernández, Alfredo; Garreau, Mireille

    2013-11-01

    The acquisition of ECG-gated cine magnetic resonance images of the heart is routinely performed in apnea in order to suppress the motion artifacts caused by breathing. However, many factors including the 2D nature of the acquisition and the use of di erent beats to acquire the multiple-view cine images, cause this kind of artifacts to appear. This paper presents the qualitative evaluation of a method aiming to remove motion artifacts in multipleview cine images acquired on patients with hypertrophic cardiomyopathy diagnosis. The approach uses iconic registration to reduce for in-plane artifacts in long-axis-view image stacks and in-plane and out-of-plane motion artifacts in sort-axis-view image stack. Four similarity measures were evaluated: the normalized correlation, the normalized mutual information, the sum of absolute voxel di erences and the Slomka metric proposed by Slomka et al. The qualitative evaluation assessed the misalignment of di erent anatomical structures of the left ventricle as follows: the misalignment of the interventricular septum and the lateral wall for short-axis-view acquisitions and the misalignment between the short-axis-view image and long-axis-view images. Results showed the correction using the normalized correlation as the most appropriated with an 80% of success.

  18. New respiratory gating technique for whole heart cine imaging: integration of a navigator slice in steady state free precession sequences.

    Science.gov (United States)

    Uribe, Sergio; Tejos, Cristian; Razavi, Reza; Schaeffter, Tobias

    2011-07-01

    To evaluate the performance of a slice navigator sequence integrated into a b-SSFP sequence for obtaining real time respiratory self-gated whole heart cine imaging. In this work, we present a novel and robust approach for respiratory motion detection by integrating a slice navigator sequence into a balanced steady state free precession (b-SSFP) sequence, while maintaining the steady state. The slice navigator sequence is integrated into consecutive repetition times (TRs) of a b-SSFP sequence to excite and read out a navigator slice. We performed several phantom experiments to test the performance of the slice navigator sequence. Additionally, the method was evaluated in five volunteers and compared with breathing signals obtained from conventional pencil beam navigator sequence. Finally, the navigator slice was used to obtain whole heart MR cine images. The breathing signals detected by the proposed method showed an excellent agreement with those obtained from pencil beam navigators. Moreover, the technique was capable of removing respiratory motion artifacts with minimal distortion of the steady state. Image quality comparison showed a statistical significant improvement from a quality score of 2.1 obtained by the nonrespiratory gated images, compared to a quality score of 3.4 obtained by the respiratory gated images. This novel method represents a robust approach to estimate breathing motion during SSFP imaging. The technique was successfully applied to acquire whole heart artifact-free cine images. Copyright © 2011 Wiley-Liss, Inc.

  19. Quantitative measurement of normal and hydrocephalic cerebrospinal fluid flow using phase contrast cine MR imaging

    International Nuclear Information System (INIS)

    Katayama, Shinji; Asari, Shoji; Ohmoto, Takashi

    1993-01-01

    Measurements of the cerebrospinal fluid (CSF) flow using phase contrast cine magnetic resonance (MR) imaging were performed on a phantom, 12 normal subjects and 20 patients with normal pressure hydrocephalus (NPH). The phantom study demonstrated the applicability of phase contrast in quantitative measurement of the slow flow. The CSF flows of the normal subjects showed a consistent pattern with a to-and-fro movement of the flow in the anterior subarachnoid space at the C2/3 level, and they were dependent on the cardiac cycle in all subjects. However, the patients with NPH showed variable patterns of the CSF pulsatile flow and these patterns could be divided into four types according to velocity and amplitude. The amplitudes of each type were as follows: type 0 (n=1), 87.6 mm; type I (n=2), 58.2 mm (mean); type II (n=6), 48.0±5.0 mm (mean±SEM); and type III (n=11), 19.9±1.8 mm (mean±SEM). The decrease of the amplitudes correlated to a worsening of the clinical symptoms. After the shunting operation, the amplitude of to-and-fro movement of the CSF increased again in the patients with NPH who improved clinically. Some of the type III cases were reclassified type II, I and 0 and also one of the type II cases changed type I after the shunting operation. We conclude that the phase contrast cine MR imaging is a practically and clinically applicable technique for the quantitative measurement of the CSF flow. (author)

  20. Evaluation of ventricular dysfunction using semi-automatic longitudinal strain analysis of four-chamber cine MR imaging.

    Science.gov (United States)

    Kawakubo, Masateru; Nagao, Michinobu; Kumazawa, Seiji; Yamasaki, Yuzo; Chishaki, Akiko S; Nakamura, Yasuhiko; Honda, Hiroshi; Morishita, Junji

    2016-02-01

    The aim of this study was to evaluate ventricular dysfunction using the longitudinal strain analysis in 4-chamber (4CH) cine MR imaging, and to investigate the agreement between the semi-automatic and manual measurements in the analysis. Fifty-two consecutive patients with ischemic, or non-ischemic cardiomyopathy and repaired tetralogy of Fallot who underwent cardiac MR examination incorporating cine MR imaging were retrospectively enrolled. The LV and RV longitudinal strain values were obtained by semi-automatically and manually. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff of the minimum longitudinal strain value for the detection of patients with cardiac dysfunction. The correlations between manual and semi-automatic measurements for LV and RV walls were analyzed by Pearson coefficient analysis. ROC analysis demonstrated the optimal cut-off of the minimum longitudinal strain values (εL_min) for diagnoses the LV and RV dysfunction at a high accuracy (LV εL_min = -7.8 %: area under the curve, 0.89; sensitivity, 83 %; specificity, 91 %, RV εL_min = -15.7 %: area under the curve, 0.82; sensitivity, 92 %; specificity, 68 %). Excellent correlations between manual and semi-automatic measurements for LV and RV free wall were observed (LV, r = 0.97, p cine MR imaging can evaluate LV and RV dysfunction with simply and easy measurements. The strain analysis could have extensive application in cardiac imaging for various clinical cases.

  1. Evaluation of mitral stenosis with velocity-encoded cine-magnetic resonance imaging.

    Science.gov (United States)

    Heidenreich, P A; Steffens, J; Fujita, N; O'Sullivan, M; Caputo, G R; Foster, E; Higgins, C B

    1995-02-15

    Velocity-encoded cine-magnetic resonance imaging (VEC-MRI) is a new method for quantitation of blood flow with the potential to measure high-velocity jets across stenotic valves. The objective of this study was to evaluate the ability of VEC-MRI to measure transmitral velocity in patients with mitral stenosis. Sixteen patients with known mitral stenosis were studied. A 1.5 Tesla superconducting magnet was used to obtain velocity-encoded images in the left ventricular short-axis plane. Images were obtained throughout the cardiac cycle at 3 consecutive slices beginning proximal to the mitral coaptation point. To determine the optimal slice thickness for MRI imaging, both 10 mm and 5 mm thicknesses were used. Echocardiography including continuous-wave Doppler was performed on every patient within 2 hours of MRI imaging. Peak velocity was determined for both VEC-MRI and Doppler-echo images. Two observers independently measured the VEC-MRI mitral inflow velocities. Of the 16 patients, imaged data were incomplete in only 1 study, and all images were adequate for analysis. Strong correlations were found for measurements of mitral valve gradient for both 10 mm (peak r = 0.89, mean r = 0.84) and 5 mm (peak r = 0.82, mean r = 0.95) slice thicknesses. Measurements of peak velocity with VEC-MRI (10 mm) agreed well with Doppler: mean 1.46 m/s, mean of differences (Doppler MRI) 0.38 m/s, standard deviation of differences 0.2 m/s. These findings suggest that VEC-MRI can noninvasively determine the severity of mitral stenosis.

  2. Cine-MR imaging in determining the flow characteristics of CSF and blood in spinal and intracranial lesions

    International Nuclear Information System (INIS)

    Post, M.J.D.; Quencer, R.M.; Green, B.A.; Hinks, R.S.; Sklar, E.M.L.; Patchen, S.J.

    1988-01-01

    The purpose of this prospective study was to determine the value of cine magnetic resonance (MR) imaging in assessing the flow patterns of patients with vascular cord neoplasms, spinal cord and subarachnoid cysts, obstructive hydrocephalus, and intracranial aneurysms. The authors' results in 26 patients showed that cine MR imaging can be used to (1) identify spinal neoplasms with prominent vascular supply; (2) help distinguish spinal cord cysts occurring above a spinal cord tumor from tumoral cysts; (3) determine which spinal cord or subarachnois cysts need shunting and, postoperatively, which cysts are adequately decompressed; (4) establish which tonsillar herniations in Chiari malformations may require resection; (5) determine the site of the block in obstructive hydrocephalus; and (6) determine the flow characteristics of an aneurysm

  3. Three-dimensional echo-planar cine imaging of cerebral blood supply using arterial spin labeling.

    Science.gov (United States)

    Shrestha, Manoj; Mildner, Toralf; Schlumm, Torsten; Robertson, Scott Haile; Möller, Harald

    2016-12-01

    Echo-planar imaging (EPI) with CYlindrical Center-out spatiaL Encoding (EPICYCLE) is introduced as a novel hybrid three-dimensional (3D) EPI technique. Its suitability for the tracking of a short bolus created by pseudo-continuous arterial spin labeling (pCASL) through the cerebral vasculature is demonstrated. EPICYCLE acquires two-dimensional planes of k-space along center-out trajectories. These "spokes" are rotated from shot to shot about a common axis to encode a k-space cylinder. To track a bolus of labeled blood, the same subset of evenly distributed spokes is acquired in a cine fashion after a short period of pCASL. This process is repeated for all subsets to fill the whole 3D k-space of each time frame. The passage of short pCASL boluses through the vasculature of a 3D imaging slab was successfully imaged using EPICYCLE. By choosing suitable sequence parameters, the impact of slab excitation on the bolus shape could be minimized. Parametric maps of signal amplitude, transit time, and bolus width reflected typical features of blood transport in large vessels. The EPICYCLE technique was successfully applied to track a short bolus of labeled arterial blood during its passage through the cerebral vasculature.

  4. Left ventricular volume measurements with free breathing respiratory self-gated 3-dimensional golden angle radial whole-heart cine imaging - Feasibility and reproducibility.

    Science.gov (United States)

    Holst, Karen; Ugander, Martin; Sigfridsson, Andreas

    2017-11-01

    To develop and evaluate a free breathing respiratory self-gated isotropic resolution technique for left ventricular (LV) volume measurements. A 3D radial trajectory with double golden-angle ordering was used for free-running data acquisition during free breathing in 9 healthy volunteers. A respiratory self-gating signal was extracted from the center of k-space and used with the electrocardiogram to bin all data into 3 respiratory and 25 cardiac phases. 3D image volumes were reconstructed and the LV endocardial border was segmented. LV volume measurements and reproducibility from 3D free breathing cine were compared to conventional 2D breath-held cine. No difference was found between 3D free breathing cine and 2D breath-held cine with regards to LV ejection fraction, stroke volume, end-systolic volume and end-diastolic volume (Pcine and 2D breath-held cine (Pcine and conventional 2D breath-held cine showed similar values and test-retest repeatability for LV volumes in healthy volunteers. 3D free breathing cine enabled retrospective sorting and arbitrary angulation of isotropic data, and could correctly measure LV volumes during free breathing acquisition. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Unsupervised fully automated inline analysis of global left ventricular function in CINE MR imaging.

    Science.gov (United States)

    Theisen, Daniel; Sandner, Torleif A; Bauner, Kerstin; Hayes, Carmel; Rist, Carsten; Reiser, Maximilian F; Wintersperger, Bernd J

    2009-08-01

    To implement and evaluate the accuracy of unsupervised fully automated inline analysis of global ventricular function and myocardial mass (MM). To compare automated with manual segmentation in patients with cardiac disorders. In 50 patients, cine imaging of the left ventricle was performed with an accelerated retrogated steady state free precession sequence (GRAPPA; R = 2) on a 1.5 Tesla whole body scanner (MAGNETOM Avanto, Siemens Healthcare, Germany). A spatial resolution of 1.4 x 1.9 mm was achieved with a slice thickness of 8 mm and a temporal resolution of 42 milliseconds. Ventricular coverage was based on 9 to 12 short axis slices extending from the annulus of the mitral valve to the apex with 2 mm gaps. Fully automated segmentation and contouring was performed instantaneously after image acquisition. In addition to automated processing, cine data sets were also manually segmented using a semi-automated postprocessing software. Results of both methods were compared with regard to end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), and MM. A subgroup analysis was performed in patients with normal (> or =55%) and reduced EF (<55%) based on the results of the manual analysis. Thirty-two percent of patients had a reduced left ventricular EF of <55%. Volumetric results of the automated inline analysis for EDV (r = 0.96), ESV (r = 0.95), EF (r = 0.89), and MM (r = 0.96) showed high correlation with the results of manual segmentation (all P < 0.001). Head-to-head comparison did not show significant differences between automated and manual evaluation for EDV (153.6 +/- 52.7 mL vs. 149.1 +/- 48.3 mL; P = 0.05), ESV (61.6 +/- 31.0 mL vs. 64.1 +/- 31.7 mL; P = 0.08), and EF (58.0 +/- 11.6% vs. 58.6 +/- 11.6%; P = 0.5). However, differences were significant for MM (150.0 +/- 61.3 g vs. 142.4 +/- 59.0 g; P < 0.01). The standard error was 15.6 (EDV), 9.7 (ESV), 5.0 (EF), and 17.1 (mass). The mean time for manual analysis was 15 minutes

  6. Cine magnetic resonance

    International Nuclear Information System (INIS)

    Higgins, C.B.; Sechtem, U.P.; Pflugfelder, P.

    1987-01-01

    Cine magnetic resonance (MR) is a fast MR imaging process with referencing of the imaging data to the electrocardiogram (ECG) so that images corresponding to 21-msec segments of the cardiac cycle are acquired. A series of such images, each corresponding to a 21-msec segment of the cardiac cycle, can be laced together for viewing in the cine format at a framing rate of 20 to 40 frames per second. Since cine angiograms of the heart are usually done at 30 frames per second, this technique achieves a temporal resolution adequate for the evluation of central cardiovascular function. The major application of this technique is to depict central cardiovascular function and blood flow

  7. Right ventricular volume and mass determined by cine magnetic resonance imaging in HIV patients with possible right ventricular dysfunction

    DEFF Research Database (Denmark)

    Kjaer, Andreas; Lebech, Anne-Mette; Gerstoft, Jan

    2006-01-01

    Impaired right ventricular (RV) function has been reported to occur in patients with HIV when studied by echocardiography. However, for accurate evaluation of RV function and morphology, first-pass radionuclide ventriculography (RNV) and cine magnetic resonance imaging (cine-MRI) are methods...... of choice. Studies of RV involvement in patients with HIV are of interest since pulmonary hypertension is a known serious complication of HIV recognized with increasing frequency. The aim of the present study was to characterize cardiac function and geometry in patients with HIV and reduced right...... reference values. RNV showed in 13 of the 90 patients a reduced RVEF with a standard cutoff value for RVEF of 0.50. Six of these agreed to have an additional MRI investigation performed. These 6 patients with HIV had an RVEF measured by RNV between 0.41-0.49. Measured by MRI the range of RVEF was 0...

  8. TU-E-BRA-04: Real-Time Automatic Fiducial Marker Detection in Low Contrast Cine-MV Images.

    Science.gov (United States)

    Liu, W; Lin, W; Ahmad, M; Nath, R

    2012-06-01

    Intrafraction motion tracking using beam-line MV images have gained much attention because no additional imaging dose is introduced. Since MV images have much lower contrast than kV images, a robust marker detection algorithm is a pre-requisite. In this work, we develop a novel, fast, and robust method to detect implanted markers in low-contrast cine-MV patient images. Several marker detection methods have been proposed in the recent years. These methods are all based on template matching or its derivatives. Template matching needs to match object shape that changes significantly for different implantation and projection angle. While these methods require a large number of templates to cover the different situations, they are often forced to use a smaller number of templates to reduce the computation load because their methods all require exhaustive search in the ROI. We solve this problem by synergetic use of modern but well-tested computer vision and AI techniques - detect implanted markers utilizing discriminant analysis for initialization and mean-shift feature space analysis for sequential tracking. This novel approach avoids exhaustive search by exploiting the temporal correlation between consecutive frames and makes it possible to perform more sophisticated detection at the beginning to improve the accuracy, followed by ultrafast sequential tracking after the initialization. The method was evaluated using 1149 cine-MV images from 2 prostate IMRT patients and compared with manual marker detection results from 6 researchers. The average of the manual detection results is considered as the ground truth. The average RMS errors of the automatic tracking from the ground truth are 1.9 and 2.1 pixels for the 2 patients (0.26mm/pixel). The standard deviations of the results from the 6 researchers are 2.3 and 2.6 pixels. The proposed method can achieve similar marker detection accuracy to manual detection in low-contract cine-MV images. © 2012 American Association of

  9. Assessment of left ventricular mass in sequential studies with cine MR imaging

    International Nuclear Information System (INIS)

    Tomei, E.; Semelka, R.; Wagner, S.; Mayo, J.; Chatterjee, K.; Parmley, W.W.; O'Sullivan, M.; Wolfe, C.L.; Caputo, G.; Higgins, C.B.

    1989-01-01

    The aim of this study was to measure left ventricular (LV) mass in 11 healthy volunteers, 10 patients with dilated cardiomyopathy, and eight patients with LV hypertrophy (LVH), using two sequential studies to compare the characteristics of LV mass in the same subject and in different clinical situations. All subjects underwent short- axis cine MR imaging at 1.5 T. Each subject had two separate studies: the healthy volunteers within 6 months and those with cardiac disease within 1 week. Measurements (both end- systolic and end-diastolic) included LV mass, LV mass index, and wall thickness. LV mass was substantially increased in both DCM and LVH. The interstudy variability for end- systolic and end-diastolic mass was 5.2% and 3.8%, respectively, for healthy volunteers, 5.2% and 4.0% for LVH, and 3.8% and 6.1% for DCM. The low variability indicates the reproducibility of this technique in sequential studies when no change is expected

  10. SU-G-BRA-03: PCA Based Imaging Angle Optimization for 2D Cine MRI Based Radiotherapy Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T; Yue, N; Jabbour, S; Zhang, M [Rutgers University, New Brunswick, NJ (United States)

    2016-06-15

    Purpose: To develop an imaging angle optimization methodology for orthogonal 2D cine MRI based radiotherapy guidance using Principal Component Analysis (PCA) of target motion retrieved from 4DCT. Methods: We retrospectively analyzed 4DCT of 6 patients with lung tumor. A radiation oncologist manually contoured the target volume at the maximal inhalation phase of the respiratory cycle. An object constrained deformable image registration (DIR) method has been developed to track the target motion along the respiration at ten phases. The motion of the center of the target mass has been analyzed using the PCA to find out the principal motion components that were uncorrelated with each other. Two orthogonal image planes for cineMRI have been determined using this method to minimize the through plane motion during MRI based radiotherapy guidance. Results: 3D target respiratory motion for all 6 patients has been efficiently retrieved from 4DCT. In this process, the object constrained DIR demonstrated satisfactory accuracy and efficiency to enable the automatic motion tracking for clinical application. The average motion amplitude in the AP, lateral, and longitudinal directions were 3.6mm (min: 1.6mm, max: 5.6mm), 1.7mm (min: 0.6mm, max: 2.7mm), and 5.6mm (min: 1.8mm, max: 16.1mm), respectively. Based on PCA, the optimal orthogonal imaging planes were determined for cineMRI. The average angular difference between the PCA determined imaging planes and the traditional AP and lateral imaging planes were 47 and 31 degrees, respectively. After optimization, the average amplitude of through plane motion reduced from 3.6mm in AP images to 2.5mm (min:1.3mm, max:3.9mm); and from 1.7mm in lateral images to 0.6mm (min: 0.2mm, max:1.5mm), while the principal in plane motion amplitude increased from 5.6mm to 6.5mm (min: 2.8mm, max: 17mm). Conclusion: DIR and PCA can be used to optimize the orthogonal image planes of cineMRI to minimize the through plane motion during radiotherapy

  11. Validation of a method for in vivo 3D dose reconstruction for IMRT and VMAT treatments using on-treatment EPID images and a model-based forward-calculation algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Van Uytven, Eric, E-mail: eric.vanuytven@cancercare.mb.ca; Van Beek, Timothy [Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); McCowan, Peter M. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada and Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Chytyk-Praznik, Krista [Medical Physics Department, Nova Scotia Cancer Centre, 5820 University Avenue, Halifax, Nova Scotia B3H 1V7 (Canada); Greer, Peter B. [School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, NSW 2308 (Australia); Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Newcastle, NSW 2298 (Australia); McCurdy, Boyd M. C. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Radiology, University of Manitoba, 820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9 (Canada)

    2015-12-15

    Purpose: Radiation treatments are trending toward delivering higher doses per fraction under stereotactic radiosurgery and hypofractionated treatment regimens. There is a need for accurate 3D in vivo patient dose verification using electronic portal imaging device (EPID) measurements. This work presents a model-based technique to compute full three-dimensional patient dose reconstructed from on-treatment EPID portal images (i.e., transmission images). Methods: EPID dose is converted to incident fluence entering the patient using a series of steps which include converting measured EPID dose to fluence at the detector plane and then back-projecting the primary source component of the EPID fluence upstream of the patient. Incident fluence is then recombined with predicted extra-focal fluence and used to calculate 3D patient dose via a collapsed-cone convolution method. This method is implemented in an iterative manner, although in practice it provides accurate results in a single iteration. The robustness of the dose reconstruction technique is demonstrated with several simple slab phantom and nine anthropomorphic phantom cases. Prostate, head and neck, and lung treatments are all included as well as a range of delivery techniques including VMAT and dynamic intensity modulated radiation therapy (IMRT). Results: Results indicate that the patient dose reconstruction algorithm compares well with treatment planning system computed doses for controlled test situations. For simple phantom and square field tests, agreement was excellent with a 2%/2 mm 3D chi pass rate ≥98.9%. On anthropomorphic phantoms, the 2%/2 mm 3D chi pass rates ranged from 79.9% to 99.9% in the planning target volume (PTV) region and 96.5% to 100% in the low dose region (>20% of prescription, excluding PTV and skin build-up region). Conclusions: An algorithm to reconstruct delivered patient 3D doses from EPID exit dosimetry measurements was presented. The method was applied to phantom and patient

  12. Influence of Spatial Resolution in Three-dimensional Cine Phase Contrast Magnetic Resonance Imaging on the Accuracy of Hemodynamic Analysis.

    Science.gov (United States)

    Fukuyama, Atsushi; Isoda, Haruo; Morita, Kento; Mori, Marika; Watanabe, Tomoya; Ishiguro, Kenta; Komori, Yoshiaki; Kosugi, Takafumi

    2017-10-10

    We aim to elucidate the effect of spatial resolution of three-dimensional cine phase contrast magnetic resonance (3D cine PC MR) imaging on the accuracy of the blood flow analysis, and examine the optimal setting for spatial resolution using flow phantoms. The flow phantom has five types of acrylic pipes that represent human blood vessels (inner diameters: 15, 12, 9, 6, and 3 mm). The pipes were fixed with 1% agarose containing 0.025 mol/L gadolinium contrast agent. A blood-mimicking fluid with human blood property values was circulated through the pipes at a steady flow. Magnetic resonance (MR) images (three-directional phase images with speed information and magnitude images for information of shape) were acquired using the 3-Tesla MR system and receiving coil. Temporal changes in spatially-averaged velocity and maximum velocity were calculated using hemodynamic analysis software. We calculated the error rates of the flow velocities based on the volume flow rates measured with a flowmeter and examined measurement accuracy. When the acrylic pipe was the size of the thoracicoabdominal or cervical artery and the ratio of pixel size for the pipe was set at 30% or lower, spatially-averaged velocity measurements were highly accurate. When the pixel size ratio was set at 10% or lower, maximum velocity could be measured with high accuracy. It was difficult to accurately measure maximum velocity of the 3-mm pipe, which was the size of an intracranial major artery, but the error for spatially-averaged velocity was 20% or less. Flow velocity measurement accuracy of 3D cine PC MR imaging for pipes with inner sizes equivalent to vessels in the cervical and thoracicoabdominal arteries is good. The flow velocity accuracy for the pipe with a 3-mm-diameter that is equivalent to major intracranial arteries is poor for maximum velocity, but it is relatively good for spatially-averaged velocity.

  13. Impact of low signal intensity assessed by cine magnetic resonance imaging on detection of poorly viable myocardium in patients with prior myocardial infarction.

    Science.gov (United States)

    Ota, Shingo; Tanimoto, Takashi; Orii, Makoto; Hirata, Kumiko; Shiono, Yasutsugu; Shimamura, Kunihiro; Matsuo, Yoshiki; Yamano, Takashi; Ino, Yasushi; Kitabata, Hironori; Yamaguchi, Tomoyuki; Kubo, Takashi; Tanaka, Atsushi; Imanishi, Toshio; Akasaka, Takashi

    2015-05-13

    Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been established as a modality to detect myocardial infarction (MI). However, the use of gadolinium contrast is limited in patients with advanced renal dysfunction. Although the signal intensity (SI) of infarct area assessed by cine MRI is low in some patients with prior MI, the prevalence and clinical significance of low SI has not been evaluated. The aim of this study was to evaluate how low SI assessed by cine MRI may relate to the myocardial viability in patients with prior MI. Fifty patients with prior MI underwent both cine MRI and LGE-MRI. The left ventricle was divided into 17 segments. The presence of low SI and the wall motion score (WMS) of each segment were assessed by cine MRI. The transmural extent of infarction was evaluated by LGE-MRI. LGE was detected in 329 of all 850 segments (39%). The low SI assessed by cine MRI was detected in 105 of 329 segments with LGE (32%). All segments with low SI had LGE. Of all 329 segments with LGE, the segments with low SI showed greater transmural extent of infarction (78 [72 - 84] % versus 53 [38 - 72] %, P cine MRI may be effective for detecting poorly viable myocardium in patients with prior MI.

  14. Compressed sensing cine imaging with high spatial or high temporal resolution for analysis of left ventricular function.

    Science.gov (United States)

    Goebel, Juliane; Nensa, Felix; Schemuth, Haemi P; Maderwald, Stefan; Gratz, Marcel; Quick, Harald H; Schlosser, Thomas; Nassenstein, Kai

    2016-08-01

    To assess two compressed sensing cine magnetic resonance imaging (MRI) sequences with high spatial or high temporal resolution in comparison to a reference steady-state free precession cine (SSFP) sequence for reliable quantification of left ventricular (LV) volumes. LV short axis stacks of two compressed sensing breath-hold cine sequences with high spatial resolution (SPARSE-SENSE HS: temporal resolution: 40 msec, in-plane resolution: 1.0 × 1.0 mm(2) ) and high temporal resolution (SPARSE-SENSE HT: temporal resolution: 11 msec, in-plane resolution: 1.7 × 1.7 mm(2) ) and of a reference cine SSFP sequence (standard SSFP: temporal resolution: 40 msec, in-plane resolution: 1.7 × 1.7 mm(2) ) were acquired in 16 healthy volunteers on a 1.5T MR system. LV parameters were analyzed semiautomatically twice by one reader and once by a second reader. The volumetric agreement between sequences was analyzed using paired t-test, Bland-Altman plots, and Passing-Bablock regression. Small differences were observed between standard SSFP and SPARSE-SENSE HS for stroke volume (SV; -7 ± 11 ml; P = 0.024), ejection fraction (EF; -2 ± 3%; P = 0.019), and myocardial mass (9 ± 9 g; P = 0.001), but not for end-diastolic volume (EDV; P = 0.079) and end-systolic volume (ESV; P = 0.266). No significant differences were observed between standard SSFP and SPARSE-SENSE HT regarding EDV (P = 0.956), SV (P = 0.088), and EF (P = 0.103), but for ESV (3 ± 5 ml; P = 0.039) and myocardial mass (8 ± 10 ml; P = 0.007). Bland-Altman analysis showed good agreement between the sequences (maximum bias ≤ -8%). Two compressed sensing cine sequences, one with high spatial resolution and one with high temporal resolution, showed good agreement with standard SSFP for LV volume assessment. J. Magn. Reson. Imaging 2016;44:366-374. © 2016 Wiley Periodicals, Inc.

  15. Monitoring tumor motion with on-line mega-voltage cone-beam computed tomography imaging in a cine mode

    International Nuclear Information System (INIS)

    Reitz, Bodo; Gayou, Olivier; Parda, David S; Miften, Moyed

    2008-01-01

    Accurate daily patient localization is becoming increasingly important in external-beam radiotherapy (RT). Mega-voltage cone-beam computed tomography (MV-CBCT) utilizing a therapy beam and an on-board electronic portal imager can be used to localize tumor volumes and verify the patient's position prior to treatment. MV-CBCT produces a static volumetric image and therefore can only account for inter-fractional changes. In this work, the feasibility of using the MV-CBCT raw data as a fluoroscopic series of portal images to monitor tumor changes due to e.g. respiratory motion was investigated. A method was developed to read and convert the CB raw data into a cine. To improve the contrast-to-noise ratio on the MV-CB projection data, image post-processing with filtering techniques was investigated. Volumes of interest from the planning CT were projected onto the MV-cine. Because of the small exposure and the varying thickness of the patient depending on the projection angle, soft-tissue contrast was limited. Tumor visibility as a function of tumor size and projection angle was studied. The method was well suited in the upper chest, where motion of the tumor as well as of the diaphragm could be clearly seen. In the cases of patients with non-small cell lung cancer with medium or large tumor masses, we verified that the tumor mass was always located within the PTV despite respiratory motion. However for small tumors the method is less applicable, because the visibility of those targets becomes marginal. Evaluation of motion in non-superior-inferior directions might also be limited for small tumor masses. Viewing MV-CBCT data in a cine mode adds to the utility of MV-CBCT for verification of tumor motion and for deriving individualized treatment margins

  16. Influence of longitudinal position on the evolution of steady-state signal in cardiac cine balanced steady-state free precession imaging.

    Science.gov (United States)

    Spear, Tyler J; Stromp, Tori A; Leung, Steve W; Vandsburger, Moriel H

    2017-11-01

    Emerging quantitative cardiac magnetic resonance imaging (CMRI) techniques use cine balanced steady-state free precession (bSSFP) to measure myocardial signal intensity and probe underlying physiological parameters. This correlation assumes that steady-state is maintained uniformly throughout the heart in space and time. To determine the effects of longitudinal cardiac motion and initial slice position on signal deviation in cine bSSFP imaging by comparing two-dimensional (2D) and three-dimensional (3D) acquisitions. Nine healthy volunteers completed cardiac MRI on a 1.5-T scanner. Short axis images were taken at six slice locations using both 2D and 3D cine bSSFP. 3D acquisitions spanned two slices above and below selected slice locations. Changes in myocardial signal intensity were measured across the cardiac cycle and compared to longitudinal shortening. For 2D cine bSSFP, 46% ± 9% of all frames and 84% ± 13% of end-diastolic frames remained within 10% of initial signal intensity. For 3D cine bSSFP the proportions increased to 87% ± 8% and 97% ± 5%. There was no correlation between longitudinal shortening and peak changes in myocardial signal. The initial slice position significantly impacted peak changes in signal intensity for 2D sequences ( P  cine bSSFP that is only restored at the center of a 3D excitation volume. During diastole, a transient steady-state is established similar to that achieved with 3D cine bSSFP regardless of slice location.

  17. Dynamic motion analysis of fetuses with central nervous system disorders by cine magnetic resonance imaging using fast imaging employing steady-state acquisition and parallel imaging: a preliminary result.

    Science.gov (United States)

    Guo, Wan-Yuo; Ono, Shigeki; Oi, Shizuo; Shen, Shu-Huei; Wong, Tai-Tong; Chung, Hsiao-Wen; Hung, Jeng-Hsiu

    2006-08-01

    The authors present a novel cine magnetic resonance (MR) imaging, two-dimensional (2D) fast imaging employing steady-state acquisition (FIESTA) technique with parallel imaging. It achieves temporal resolution at less than half a second as well as high spatial resolution cine imaging free of motion artifacts for evaluating the dynamic motion of fetuses in utero. The information obtained is used to predict postnatal outcome. Twenty-five fetuses with anomalies were studied. Ultrasonography demonstrated severe abnormalities in five of the fetuses; the other 20 fetuses constituted a control group. The cine fetal MR imaging demonstrated fetal head, neck, trunk, extremity, and finger as well as swallowing motions. Imaging findings were evaluated and compared in fetuses with major central nervous system (CNS) anomalies in five cases and minor CNS, non-CNS, or no anomalies in 20 cases. Normal motility was observed in the latter group. For fetuses in the former group, those with abnormal motility failed to survive after delivery, whereas those with normal motility survived with functioning preserved. The power deposition of radiofrequency, presented as specific absorption rate (SAR), was calculated. The SAR of FIESTA was approximately 13 times lower than that of conventional MR imaging of fetuses obtained using single-shot fast spin echo sequences. The following conclusions are drawn: 1) Fetal motion is no longer a limitation for prenatal imaging after the implementation of parallel imaging with 2D FIESTA, 2) Cine MR imaging illustrates fetal motion in utero with high clinical reliability, 3) For cases involving major CNS anomalies, cine MR imaging provides information on extremity motility in fetuses and serves as a prognostic indicator of postnatal outcome, and 4) The cine MR used to observe fetal activity is technically 2D and conceptually three-dimensional. It provides four-dimensional information for making proper and timely obstetrical and/or postnatal management

  18. On the evaluation of patient specific IMRT QA using EPID, dynalog files and patient anatomy

    OpenAIRE

    Dewayne Lee Defoor; Panayiotis Mavroidis; L Vazquez Quino; Alonso Gutierrez; Niko Papanikolaou; Sotiri Stathakis

    2014-01-01

    Purpose: This research, investigates the viability of using the Electronic portal imaging device (EPID) coupled with the treatment planning system (TPS), to calculate the doses delivered and verify agreement with the treatment plan. The results of QA analysis using the EPID, Delta4 and fluence calculations using the multi-leaf collimator (MLC) dynalog files on 10 IMRT patients are presented in this study.Methods: EPID Fluence Images in integrated mode and Dynalog files for each field were acq...

  19. The thoracic aortography by Gd-DTPA enhanced ultrafast cine MR imaging. Assessment of thoracic aortic dilatation in aging and in patients with hypertension and aortic valve disease

    International Nuclear Information System (INIS)

    Matsumura, Kentaro; Nakase, Emiko; Kawai, Ichiyoshi; Saito, Takayuki; Kikkawa, Nobutada; Haiyama, Toru

    1995-01-01

    To assess the morphology of thoracic aorta, we had a trial of Gd-DTPA enhanced ultrafast cine MR imaging on the thoracic aorta. This method was provided with high quality thoracic aortogram during 15-20 seconds. In patients without hypertension and aortic valve disease, dimensions of ascending aorta and aortic arch were significantly correlated with aging. In patients with hypertension, dimensions of ascending aorta and aortic arch were significantly dilated. In patients with aortic valve disease, thoracic aorta was diffusely enlarged, especially in ascending aorta. Gd-DTPA enhanced ultrafact cine MR imaging was useful to assess the thoracic aortic anatomy and diseases. (author)

  20. Spirometer-controlled Cine-Magnetic Resonance Imaging for Diagnosis of Tracheobronchomalacia in Pediatric Patients

    NARCIS (Netherlands)

    Ciet, P.; Wielopolski, P.; Manniesing, R.; Lever, S.; Bruijne, M. de; Morana, G.; Muzzio, P.C.; Lequin, M.H.; Tiddens, H.A.W.M.

    2014-01-01

    Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard to diagnose TBM, but bronchoscopy has major disadvantages, such as general anaesthesia. Cine-CT is a non-invasive alternative to diagnose TBM, but its use in children is

  1. TH-EF-BRA-08: A Novel Technique for Estimating Volumetric Cine MRI (VC-MRI) From Multi-Slice Sparsely Sampled Cine Images Using Motion Modeling and Free Form Deformation

    International Nuclear Information System (INIS)

    Harris, W; Yin, F; Wang, C; Chang, Z; Cai, J; Zhang, Y; Ren, L

    2016-01-01

    Purpose: To develop a technique to estimate on-board VC-MRI using multi-slice sparsely-sampled cine images, patient prior 4D-MRI, motion-modeling and free-form deformation for real-time 3D target verification of lung radiotherapy. Methods: A previous method has been developed to generate on-board VC-MRI by deforming prior MRI images based on a motion model(MM) extracted from prior 4D-MRI and a single-slice on-board 2D-cine image. In this study, free-form deformation(FD) was introduced to correct for errors in the MM when large anatomical changes exist. Multiple-slice sparsely-sampled on-board 2D-cine images located within the target are used to improve both the estimation accuracy and temporal resolution of VC-MRI. The on-board 2D-cine MRIs are acquired at 20–30frames/s by sampling only 10% of the k-space on Cartesian grid, with 85% of that taken at the central k-space. The method was evaluated using XCAT(computerized patient model) simulation of lung cancer patients with various anatomical and respirational changes from prior 4D-MRI to onboard volume. The accuracy was evaluated using Volume-Percent-Difference(VPD) and Center-of-Mass-Shift(COMS) of the estimated tumor volume. Effects of region-of-interest(ROI) selection, 2D-cine slice orientation, slice number and slice location on the estimation accuracy were evaluated. Results: VCMRI estimated using 10 sparsely-sampled sagittal 2D-cine MRIs achieved VPD/COMS of 9.07±3.54%/0.45±0.53mm among all scenarios based on estimation with ROI_MM-ROI_FD. The FD optimization improved estimation significantly for scenarios with anatomical changes. Using ROI-FD achieved better estimation than global-FD. Changing the multi-slice orientation to axial, coronal, and axial/sagittal orthogonal reduced the accuracy of VCMRI to VPD/COMS of 19.47±15.74%/1.57±2.54mm, 20.70±9.97%/2.34±0.92mm, and 16.02±13.79%/0.60±0.82mm, respectively. Reducing the number of cines to 8 enhanced temporal resolution of VC-MRI by 25% while

  2. Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images

    NARCIS (Netherlands)

    Zweerink, A.; Allaart, C.P.; Kuijer, J.P.A.; Wu, L.; Beek, A.M.; Ven, P.M. van de; Meine, M.; Croisille, P.; Clarysse, P.; Rossum, A.C. van; Nijveldt, R.

    2017-01-01

    OBJECTIVES: Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive

  3. Portal hypertension in patients with cirrhosis: indirect assessment of hepatic venous pressure gradient by measuring azygos flow with 2D-cine phase-contrast magnetic resonance imaging.

    Science.gov (United States)

    Gouya, Hervé; Grabar, Sophie; Vignaux, Olivier; Saade, Anastasia; Pol, Stanislas; Legmann, Paul; Sogni, Philippe

    2016-07-01

    To measure azygos, portal and aortic flow by two-dimensional cine phase-contrast magnetic resonance imaging (2D-cine PC MRI), and to compare the MRI values to hepatic venous pressure gradient (HVPG) measurements, in patients with cirrhosis. Sixty-nine patients with cirrhosis were prospectively included. All patients underwent HVPG measurements, upper gastrointestinal endoscopy and 2D-cine PC MRI measurements of azygos, portal and aortic blood flow. Univariate and multivariate regression analyses were used to evaluate the correlation between the blood flow and HVPG. The performance of 2D-cine PC MRI to diagnose severe portal hypertension (HVPG ≥ 16 mmHg) was determined by receiver operating characteristic curve (ROC) analysis, and area under the curves (AUC) were compared. Azygos and aortic flow values were associated with HVPG in univariate linear regression model. Azygos flow (p cine PC MRI is a promising technique to evaluate significant portal hypertension in patients with cirrhosis. • Noninvasive HVPG assessment can be performed with MRI azygos flow. • Azygos MRI flow is an easy-to-measure marker to detect significant portal hypertension. • MRI flow is more specific that varice grade to detect portal hypertension.

  4. Impact of Surgical Evaluation of Additional Cine Magnetic Resonance Imaging for Advanced Thymoma with Infiltration of Adjacent Structures: The Thoracic Surgeon's View.

    Science.gov (United States)

    Ried, Michael; Hnevkovsky, Stefanie; Neu, Reiner; von Süßkind-Schwendi, Marietta; Götz, Andrea; Hamer, Okka W; Schalke, Berthold; Hofmann, Hans-Stefan

    2017-04-01

    Background  Preoperative radiological assessment is important for clarification of surgical operability for advanced thymic tumors. Objective was to determine the feasibility of magnetic resonance imaging (MRI) with cine sequences for evaluation of cardiovascular tumor invasion. Patients and Methods  This prospective study included patients with advanced thymoma, who underwent surgical resection. All patients received preoperative computed tomography (CT) scan and cine MRI. Results  Tumor infiltration was surgically confirmed in the pericardium ( n  = 12), myocardium ( n  = 1), superior caval vein (SCV; n  = 3), and aorta ( n  = 2). A macroscopic complete resection was possible in 10 patients, whereas 2 patients with aortic or myocardial tumor invasion had R2 resection. The positive predictive value (PPV) was 50% for cine MRI compared with 0% for CT scan regarding myocardial tumor infiltration. The PPV for tumor infiltration of the aorta was 50%, with a higher sensitivity for the CT scan (100 vs. 50%). Infiltration of the SCV could be detected slightly better with cine MRI (PPV 75 vs. 66.7%). Conclusion  Cine MRI seems to improve the accuracy of preoperative staging of advanced thymoma regarding infiltration of cardiovascular structures and supports the surgical approach. Georg Thieme Verlag KG Stuttgart · New York.

  5. SU-E-T-291: Sensitivity of a Simple 2D EPID in Vivo Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Peca, S; Brown, D [University of Calgary, Tom Baker Cancer Centre, Calgary, AB (Canada)

    2014-06-01

    Purpose: As radiotherapy (RT) increases in complexity, so does motivation for in vivo dosimetry (IVD), which may detect errors such as: setup, beam shaping and dose delivered. We have recently developed an easy-toimplement method for two-dimensional IVD based on images taken with the electronic portal imaging device (EPID) in cine mode during treatment. The purpose of this work is to characterize its sensitivity to possible RT delivery errors. Methods: We introduced a series of modifications to a simple RT field (10×10, 100MU, 300RR, 20cm homogeneous phantom) to simulate errors. These modifications included multi-leaf collimator (MLC) position, number of MUs, and collimator angle. We quantified the sensitivity to inhomogeneities by inserting variable amounts of solid lung and bone. Finally we delivered realistic fields to an anthropomorphic phantom to estimate sensitivity to gantry angle and setup errors. Results: Our EPIDIVD is sensitive to MLC positioning errors of 1mm and 3mm in the closed and open directions respectively, and to 3% MU variations. Sensitivity to collimator angle depends on field shape irregularity; in the case of a 10x10 field, we are sensitive to errors of 0.8°. The sensitivity to inhomogeneities is limited by the nature of MV imaging: approximately 1% signal change is noted when switching 5cm of water to equal amounts of bone or lung. This suggests that the EPID-IVD is likely not sensitive to small setup or gantry angle errors, as confirmed by anthropomorphic tests. Conclusion: We have characterized a simple method of 2D dose reconstruction at isocenter depth inside the patient, which is sensitive to possible RT delivery errors. This method may be useful as a secondary safety check, to prevent large errors from being carried on to following fractions, and to record delivered dose. By using readily available hardware, it is easily implemented and may prove especially useful in centers with limited resources.

  6. Real-time cardiac magnetic resonance cine imaging with sparse sampling and iterative reconstruction for left-ventricular measures: Comparison with gold-standard segmented steady-state free precession.

    Science.gov (United States)

    Camargo, Gabriel C; Erthal, Fernanda; Sabioni, Leticia; Penna, Filipe; Strecker, Ralph; Schmidt, Michaela; Zenge, Michael O; Lima, Ronaldo de S L; Gottlieb, Ilan

    2017-05-01

    Segmented cine imaging with a steady-state free-precession sequence (Cine-SSFP) is currently the gold standard technique for measuring ventricular volumes and mass, but due to multi breath-hold (BH) requirements, it is prone to misalignment of consecutive slices, time consuming and dependent on respiratory capacity. Real-time cine avoids those limitations, but poor spatial and temporal resolution of conventional sequences has prevented its routine application. We sought to examine the accuracy and feasibility of a newly developed real-time sequence with aggressive under-sampling of k-space using sparse sampling and iterative reconstruction (Cine-RT). Stacks of short-axis cines were acquired covering both ventricles in a 1.5T system using gold standard Cine-SSFP and Cine-RT. Acquisition parameters for Cine-SSFP were: acquisition matrix of 224×196, temporal resolution of 39ms, retrospective gating, with an average of 8 heartbeats per slice and 1-2 slices/BH. For Cine-RT: acquisition matrix of 224×196, sparse sampling net acceleration factor of 11.3, temporal resolution of 41ms, prospective gating, real-time acquisition of 1 heart-beat/slice and all slices in one BH. LV contours were drawn at end diastole and systole to derive LV volumes and mass. Forty-one consecutive patients (15 male; 41±17years) in sinus rhythm were successfully included. All images from Cine-SSFP and Cine-RT were considered to have excellent quality. Cine-RT-derived LV volumes and mass were slightly underestimated but strongly correlated with gold standard Cine-SSFP. Inter- and intra-observer analysis presented similar results between both sequences. Cine-RT featuring sparse sampling and iterative reconstruction can achieve spatial and temporal resolution equivalent to Cine-SSFP, providing excellent image quality, with similar precision measurements and highly correlated and only slightly underestimated volume and mass values. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Fast cine-magnetic resonance imaging point tracking for prostate cancer radiation therapy planning

    International Nuclear Information System (INIS)

    Dowling, J; Chandra, S; Dang, K; Fox, Chris D; Gill, Suki; Kron, T; Pham, D; Foroudi, F

    2014-01-01

    The analysis of intra-fraction organ motion is important for improving the precision of radiation therapy treatment delivery. One method to quantify this motion is for one or more observers to manually identify anatomic points of interest (POIs) on each slice of a cine-MRI sequence. However this is labour intensive and inter- and intra- observer variation can introduce uncertainty. In this paper a fast method for non-rigid registration based point tracking in cine-MRI sagittal and coronal series is described which identifies POIs in 0.98 seconds per sagittal slice and 1.35 seconds per coronal slice. The manual and automatic points were highly correlated (r>0.99, p<0.001) for all organs and the difference generally less than 1mm. For prostate planning peristalsis and rectal gas can result in unpredictable out of plane motion, suggesting the results may require manual verification.

  8. Fast cine-magnetic resonance imaging point tracking for prostate cancer radiation therapy planning

    Science.gov (United States)

    Dowling, J.; Dang, K.; Fox, Chris D.; Chandra, S.; Gill, Suki; Kron, T.; Pham, D.; Foroudi, F.

    2014-03-01

    The analysis of intra-fraction organ motion is important for improving the precision of radiation therapy treatment delivery. One method to quantify this motion is for one or more observers to manually identify anatomic points of interest (POIs) on each slice of a cine-MRI sequence. However this is labour intensive and inter- and intra- observer variation can introduce uncertainty. In this paper a fast method for non-rigid registration based point tracking in cine-MRI sagittal and coronal series is described which identifies POIs in 0.98 seconds per sagittal slice and 1.35 seconds per coronal slice. The manual and automatic points were highly correlated (r>0.99, pmanual verification.

  9. Self-gated CINE MRI for combined contrast-enhanced imaging and wall-stiffness measurements of murine aortic atherosclerotic lesions

    NARCIS (Netherlands)

    den Adel, Brigit; van der Graaf, Linda M.; Strijkers, Gustav J.; Lamb, Hildo J.; Poelmann, Robert E.; van der Weerd, Louise

    2013-01-01

    High-resolution contrast-enhanced imaging of the murine atherosclerotic vessel wall is difficult due to unpredictable flow artifacts, motion of the thin artery wall and problems with flow suppression in the presence of a circulating contrast agent. We applied a 2D-FLASH retrospective-gated CINE MRI

  10. A novel diagnostic aid for intra-abdominal adhesion detection in cine-MR imaging: Pilot study and initial diagnostic impressions.

    Science.gov (United States)

    Randall, David; Joosten, Frank; ten Broek, Richard; Gillott, Richard; Bardhan, Karna Dev; Strik, Chema; Prins, Wiesje; van Goor, Harry; Fenner, John

    2017-07-14

    A non-invasive diagnostic technique for abdominal adhesions is not currently available. Capture of abdominal motion due to respiration in cine-MRI has shown promise, but is difficult to interpret. This article explores the value of a complimentary diagnostic aid to facilitate the non-invasive detection of abdominal adhesions using cine-MRI. An image processing technique was developed to quantify the amount of sliding that occurs between the organs of the abdomen and the abdominal wall in sagittal cine-MRI slices. The technique produces a 'sheargram' which depicts the amount of sliding which has occurred over 1-3 respiratory cycles. A retrospective cohort of 52 patients, scanned for suspected adhesions, made 281 cine-MRI sagittal slices available for processing. The resulting sheargrams were reported by two operators and compared to expert clinical judgement of the cine-MRI scans. The sheargram matched clinical judgement in 84% of all sagittal slices and 93-96% of positive adhesions were identified on the sheargram. The sheargram displayed a slight skew towards sensitivity over specificity, with a high positive adhesion detection rate but at the expense of false positives. Good correlation between sheargram and absence/presence of inferred adhesions indicates quantification of sliding motion has potential to aid adhesion detection in cine-MRI. Advances in Knowledge: This is the first attempt to clinically evaluate a novel image processing technique quantifying the sliding motion of the abdominal contents against the abdominal wall. The results of this pilot study reveal its potential as a diagnostic aid for detection of abdominal adhesions.

  11. Development and clinical evaluation of automatic fiducial detection for tumor tracking in cine megavoltage images during volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    Azcona, Juan Diego; Li Ruijiang; Mok, Edward; Hancock, Steven; Xing Lei

    2013-01-01

    Purpose: Real-time tracking of implanted fiducials in cine megavoltage (MV) imaging during volumetric modulated arc therapy (VMAT) delivery is complicated due to the inherent low contrast of MV images and potential blockage of dynamic leaves configurations. The purpose of this work is to develop a clinically practical autodetection algorithm for motion management during VMAT. Methods: The expected field-specific segments and the planned fiducial position from the Eclipse (Varian Medical Systems, Palo Alto, CA) treatment planning system were projected onto the MV images. The fiducials were enhanced by applying a Laplacian of Gaussian filter in the spatial domain for each image, with a blob-shaped object as the impulse response. The search of implanted fiducials was then performed on a region of interest centered on the projection of the fiducial when it was within an open field including the case when it was close to the field edge or partially occluded by the leaves. A universal template formula was proposed for template matching and normalized cross correlation was employed for its simplicity and computational efficiency. The search region for every image was adaptively updated through a prediction model that employed the 3D position of the fiducial estimated from the localized positions in previous images. This prediction model allowed the actual fiducial position to be tracked dynamically and was used to initialize the search region. The artifacts caused by electronic interference during the acquisition were effectively removed. A score map was computed by combining both morphological information and image intensity. The pixel location with the highest score was selected as the detected fiducial position. The sets of cine MV images taken during treatment were analyzed with in-house developed software written in MATLAB (The Mathworks, Inc., Natick, MA). Five prostate patients were analyzed to assess the algorithm performance by measuring their positioning

  12. Significance of spin-echo intracardiac signal during cine cardiac MR imaging

    International Nuclear Information System (INIS)

    Feiglin, D.H.I.; O'Donnell, J.K.

    1987-01-01

    Thirty patient studies were performed using several multisection spin multi-echo pulse sequences (SEPS) formattable into the cine mode, with repetition time (TR)≤RR interval and 18 msec ≤ echo time (TE) ≤ 64 msec. Thirteen studies were performed in patients with various cardiomyopathies, ten in patients with cardiac tumors, and seven in healthy volunteers. The SEPS in the multi-echo acquisition format differentiated between tumor and stasis in terms of signal behavior. Healthy subjects may exhibit stasis of flow adjacent to the endocardium during the cardiac cycle

  13. Functional analysis of third ventriculostomy patency by quantification of CSF stroke volume by using cine phase-contrast MR imaging.

    Science.gov (United States)

    Bargalló, Núria; Olondo, Lourdes; Garcia, Ana I; Capurro, Sebastian; Caral, Luis; Rumia, Jordi

    2005-01-01

    Endoscopic third ventriculostomy (ETV) is increasingly used as alternative treatment for obstructive hydrocephalus. The aim of this study was to determine the utility of quantitative and qualitative examinations with cine phase-contrast MR imaging to determine the efficacy of ventriculostomy across time and whether CSF pulsation is restored after ETV. Thirty-eight patients treated with ETV were evaluated with cine phase-contrast MR within 1 month after surgery. Follow-up studies were performed after 1 year in 25 patients and after 2 years in 12. We evaluated flow void changes in the floor of the third ventricle and quantified the stroke volume at the site of the ventriculostomy. We also recorded changes in ventricular size and clinical outcome. To determine the restoration of CSF pulsation, we compared the CSF waveform at the ventriculostomy with the CSF waveform at the aqueduct in a healthy control group. After ventriculostomy, restoration of pulsate motion characteristics of CSF circulation was observed. The stroke volume registered at ventriculostomy was maintained with time. There was a statistically significant relationship between clinical outcome and stroke volume. Overall flow magnitude was the most effective variable to determine which patients would improve after surgery. Values >75 mm3 showed a sensitivity of 76.7% and a specificity of 87.5% There was no relationship between ventricular size changes and clinical outcome. Patients with primary aqueduct stenosis had the best response to surgery, whereas patients with Arnold Chiari malformation or communicating hydrocephalus had the worst response. Quantitative analysis with phase-contrast MR imaging indicates that ETV is an efficient technique for restoring CSF pulsation, with efficacy being maintained during the follow-up controls. Quantification of stroke volume at ventriculostomy is a good indicator of the functional status of ETV, and a high stroke volume in the ventriculostomy appears to be a positive

  14. Quantitative assessment of left ventricular mechanical dyssynchrony using cine cardiovascular magnetic resonance imaging: Inter-study reproducibility

    Directory of Open Access Journals (Sweden)

    Johannes T Kowallick

    2017-05-01

    Full Text Available Objectives To determine the inter-study reproducibility of left ventricular (LV mechanical dyssynchrony measures based on standard cardiovascular magnetic resonance (CMR cine images. Design Steady-state free precession (SSFP LV short-axis stacks and three long-axes were acquired on the same day at three time points. Circumferential strain systolic dyssynchrony indexes (SDI, area-SDI as well as circumferential and radial uniformity ratio estimates (CURE and RURE, respectively were derived from CMR myocardial feature-tracking (CMR-FT based on the tracking of three SSFP short-axis planes. Furthermore, 4D-LV-analysis based on SSFP short-axis stacks and longitudinal planes was performed to quantify 4D-volume-SDI. Setting A single-centre London teaching hospital. Participants 16 healthy volunteers. Main outcome measures Inter-study reproducibility between the repeated exams. Results CURE and RURE as well as 4D-volume-SDI showed good inter-study reproducibility (coefficient of variation [CoV] 6.4%–12.9%. Circumferential strain and area-SDI showed higher variability between the repeated measurements (CoV 24.9%–37.5%. Uniformity ratio estimates showed the lowest inter-study variability (CoV 6.4%–8.5%. Conclusions Derivation of LV mechanical dyssynchrony measures from standard cine images is feasible using CMR-FT and 4D-LV-analysis tools. Uniformity ratio estimates and 4D-volume-SDI showed good inter-study reproducibility. Their clinical value should next be explored in patients who potentially benefit from cardiac resynchronization therapy.

  15. Analysis of blood flow patterns in aortic aneurysm by cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Matsuoka, Hiroshi

    1993-01-01

    Cine MRI (0.5 T) using rephased gradient echo technique was performed to study the patterns of blood flow in the aortic aneurysm of 16 patients with aortic aneurysm, and the data were compared with those of 5 healthy volunteers. In the transaxial section, the blood flow in normal aorta appeared as homogeneous high intensity during systole. On the other hand, the blood flow in the aneurysm appeared as inhomogeneous flow enhancement with flow void. In the sagittal scan, the homogeneous flow enhancement in a normal aorta was also observed during systole and its apex of flow enhancement was 'taper'. The blood flow patterns in the aneurysm were classified as 'irregular', 'zonal', 'eddy', and 'obscure' depending on the contrast of flow enhancement and flow void. Their apexes were 'taper' or 'round'. The blood flow patterns in the aneurysm were related to the size of aneurysm. In patients with a large size 'aneurysm, their flow patterns were 'eddy' or 'obscure' and the flow enhancement was 'round'. On the other hand, in patients with a small size aneurysm, their flow patterns were 'irregular' or 'zonal', and their flow enhancement was 'taper'. Though the exact mechanism of abnormal flow patterns in an aortic aneurysm remains to be determined, cine MRI gives helpful informations in assessing blood flow dynamics in the aneurysm. (author)

  16. SU-F-T-240: EPID-Based Quality Assurance for Dosimetric Credentialing

    Energy Technology Data Exchange (ETDEWEB)

    Miri, N [University of Newcastle, Newcastle, NSW (Australia); Lehmann, J [Calvary Mater Newcastle, Newcastle, NSW (Australia); Vial, P [Liverpool Hospital, Sydney, NSW (Australia); Greer, P [Calvary Mater Newcastle, Newcastle, NSW (Australia); University of Newcastle, Newcastle, NSW (Australia)

    2016-06-15

    Purpose: We propose a novel dosimetric audit method for clinical trials using EPID measurements at each center and a standardized EPID to dose conversion algorithm. The aim of this work is to investigate the applicability of the EPID method to different linear accelerator, EPID and treatment planning system (TPS) combinations. Methods: Combination of delivery and planning systems were three Varian linacs including one Pinnacle and two Eclipse TPS and, two ELEKTA linacs including one Pinnacle and one Monaco TPS. All Varian linacs had the same EPID structure and similarly for the ELEKTA linacs. Initially, dose response of the EPIDs was investigated by acquiring integrated pixel value (IPV) of the central area of 10 cm2 images versus MUs, 5-400 MU. Then, the EPID to dose conversion was investigated for different system combinations. Square field size images, 2, 3, 4, 6, 10, 15, 20, 25 cm2 acquired by all systems were converted to dose at isocenter of a virtual flat phantom then the dose was compared to the corresponding TPS dose. Results: All EPIDs showed a relatively linear behavior versus MU except at low MUs which showed irregularities probably due to initial inaccuracies of irradiation. Furthermore, for all the EPID models, the model predicted TPS dose with a mean dose difference percentage of 1.3. However the model showed a few inaccuracies for ELEKTA EPID images at field sizes larger than 20 cm2. Conclusion: The EPIDs demonstrated similar behavior versus MU and the model was relatively accurate for all the systems. Therefore, the model could be employed as a global dosimetric method to audit clinical trials. Funding has been provided from Department of Radiation Oncology, TROG Cancer Research and the University of Newcastle. Narges Miri is a recipient of a University of Newcastle postgraduate scholarship.

  17. Differentiation between acute and chronic myocardial infarction by means of texture analysis of late gadolinium enhancement and cine cardiac magnetic resonance imaging.

    Science.gov (United States)

    Larroza, Andrés; Materka, Andrzej; López-Lereu, María P; Monmeneu, José V; Bodí, Vicente; Moratal, David

    2017-07-01

    The purpose of this study was to differentiate acute from chronic myocardial infarction using machine learning techniques and texture features extracted from cardiac magnetic resonance imaging (MRI). The study group comprised 22 cases with acute myocardial infarction (AMI) and 22 cases with chronic myocardial infarction (CMI). Cine and late gadolinium enhancement (LGE) MRI were analyzed independently to differentiate AMI from CMI. A total of 279 texture features were extracted from predefined regions of interest (ROIs): the infarcted area on LGE MRI, and the entire myocardium on cine MRI. Classification performance was evaluated by a nested cross-validation approach combining a feature selection technique with three predictive models: random forest, support vector machine (SVM) with Gaussian Kernel, and SVM with polynomial kernel. The polynomial SVM yielded the best classification performance. Receiver operating characteristic curves provided area-under-the-curve (AUC) (mean±standard deviation) of 0.86±0.06 on LGE MRI using 72 features; AMI sensitivity=0.81±0.08 and specificity=0.84±0.09. On cine MRI, AUC=0.82±0.06 using 75 features; AMI sensitivity=0.79±0.10 and specificity=0.80±0.10. We concluded that texture analysis can be used for differentiation of AMI from CMI on cardiac LGE MRI, and also on standard cine sequences in which the infarction is visually imperceptible in most cases. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Cardiac cine MRI: Comparison of 1.5 T, non-enhanced 3.0 T and blood pool enhanced 3.0 T imaging

    International Nuclear Information System (INIS)

    Gerretsen, S.C.; Versluis, B.; Bekkers, S.C.A.M.; Leiner, T.

    2008-01-01

    Introduction: Cardiac cine imaging using balanced steady state free precession sequences (bSSFP) suffers from artefacts at 3.0 T. We compared bSSFP cardiac cine imaging at 1.5 T with gradient echo imaging at 3.0 T with and without a blood pool contrast agent. Materials and methods: Eleven patients referred for cardiac cine imaging underwent imaging at 1.5 T and 3.0 T. At 3.0 T images were acquired before and after administration of 0.03 mmol/kg gadofosveset. Blood pool signal-to-noise ratio (SNR), temporal variations in SNR, ejection fraction and myocardial mass were compared. Subjective image quality was scored on a four-point scale. Results: Blood pool SNR increased with more than 75% at 3.0 T compared to 1.5 T (p < 0.001); after contrast administration at 3.0 T SNR increased with 139% (p < 0.001). However, variations in blood pool SNR at 3.0 T were nearly three times as high versus those at 1.5 T in the absence of contrast medium (p < 0.001); after contrast administration this was reduced to approximately a factor 1.4 (p = 0.21). Saturation artefacts led to significant overestimation of ejection fraction in the absence of contrast administration (1.5 T: 44.7 ± 3.1 vs. 3.0 T: 50.7 ± 4.2 [p = 0.04] vs. 3.0 T post contrast: 43.4 ± 2.9 [p = 0.55]). Subjective image quality was highest for 1.5 T (2.8 ± 0.3), and lowest for non-enhanced 3.0 T (1.7 ± 0.6; p = 0.006). Conclusions: GRE cardiac cine imaging at 3.0 T after injection of the blood pool agent gadofosveset leads to improved objective and subjective cardiac cine image quality at 3.0 T and to the same conclusions regarding cardiac ejection fraction compared to bSSFP imaging at 1.5 T

  19. Influence of high magnetic field strengths and parallel acquisition strategies on image quality in cardiac 2D CINE magnetic resonance imaging: comparison of 1.5 T vs. 3.0 T

    International Nuclear Information System (INIS)

    Gutberlet, Matthias; Schwinge, Kerstin; Freyhardt, Patrick; Spors, Birgit; Grothoff, Matthias; Denecke, Timm; Luedemann, Lutz; Felix, Roland; Noeske, Ralph; Niendorf, Thoralf

    2005-01-01

    The aim of this paper is to examine signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image quality of cardiac CINE imaging at 1.5 T and 3.0 T. Twenty volunteers underwent cardiac magnetic resonance imaging (MRI) examinations using a 1.5-T and a 3.0-T scanner. Three different sets of breath-held, electrocardiogram-gated (ECG) CINE imaging techniques were employed, including: (1) unaccelerated SSFP (steady state free precession), (2) accelerated SSFP imaging and (3) gradient-echo-based myocardial tagging. Two-dimensional CINE SSFP at 3.0 T revealed an SNR improvement of 103% and a CNR increase of 19% as compared to the results obtained at 1.5 T. The SNR reduction in accelerated 2D CINE SSFP imaging was larger at 1.5 T (37%) compared to 3.0 T (26%). The mean SNR and CNR increase at 3.0 T obtained for the tagging sequence was 88% and 187%, respectively. At 3.0 T, the duration of the saturation bands persisted throughout the entire cardiac cycle. For comparison, the saturation bands were significantly diminished at 1.5 T during end-diastole. For 2D CINE SSFP imaging, no significant difference in the left ventricular volumetry and in the overall image quality was obtained. For myocardial tagging, image quality was significantly improved at 3.0 T. The SNR reduction in accelerated SSFP imaging was overcompensated by the increase in the baseline SNR at 3.0 T and did not result in any image quality degradation. For cardiac tagging techniques, 3.0 T was highly beneficial, which holds the promise to improve its diagnostic value. (orig.)

  20. Single breath-hold real-time cine MR imaging: improved temporal resolution using generalized autocalibrating partially parallel acquisition (GRAPPA) algorithm

    International Nuclear Information System (INIS)

    Wintersperger, Bernd J.; Nikolaou, Konstantin; Dietrich, Olaf; Reiser, Maximilian F.; Schoenberg, Stefan O.; Rieber, Johannes; Nittka, Matthias

    2003-01-01

    The purpose of this study was to test parallel imaging techniques for improvement of temporal resolution in multislice single breath-hold real-time cine steady-state free precession (SSFP) in comparison with standard segmented single-slice SSFP techniques. Eighteen subjects were examined on a 1.5-T scanner using a multislice real-time cine SSFP technique using the GRAPPA algorithm. Global left ventricular parameters (EDV, ESV, SV, EF) were evaluated and results compared with a standard segmented single-slice SSFP technique. Results for EDV (r=0.93), ESV (r=0.99), SV (r=0.83), and EF (r=0.99) of real-time multislice SSFP imaging showed a high correlation with results of segmented SSFP acquisitions. Systematic differences between both techniques were statistically non-significant. Single breath-hold multislice techniques using GRAPPA allow for improvement of temporal resolution and for accurate assessment of global left ventricular functional parameters. (orig.)

  1. 2D XD-GRASP provides better image quality than conventional 2D cardiac cine MRI for patients who cannot suspend respiration

    Science.gov (United States)

    Piekarski, Eve; Chitiboi, Teodora; Ramb, Rebecca; Latson, Larry A; Bhatla, Puneet; Feng, Li; Axel, Leon

    2017-01-01

    Object Residual respiratory motion degrades image quality in conventional cardiac cine MRI (CCMR). We evaluated whether a free-breathing (FB) radial imaging CCMR sequence with compressed sensing reconstruction (eXtra-Dimension (e.g. cardiac and respiratory phases) Golden-angle RAdial Sparse Parallel, or XD-GRASP) could provide better image quality than a conventional Cartesian breath-held (BH) sequence, in an unselected population of patients undergoing clinical CCMR. Material and Methods 101 patients who underwent BH and FB imaging in a mid-ventricular short-axis plane at a matching location were included. Visual and quantitative image analysis was performed by two blinded experienced readers, using a 5-point qualitative scale to score overall image quality and visual signal-to-noise ratio (SNR) grade, with measures of noise and sharpness. End-diastole (ED) and end-systole (ES) left-ventricular areas were also measured and compared for both BH and FB images. Results Image quality was generally better with the BH cines (overall quality grade BH vs FB: 4 vs 2.9, pcine in general, it provided improved image quality in the subgroup of patients presenting respiratory motion-induced artifacts on breath-held images. PMID:29067539

  2. Free-breathing black-blood CINE fast-spin echo imaging for measuring abdominal aortic wall distensibility: a feasibility study

    Science.gov (United States)

    Lin, Jyh-Miin; Patterson, Andrew J.; Chao, Tzu-Cheng; Zhu, Chengcheng; Chang, Hing-Chiu; Mendes, Jason; Chung, Hsiao-Wen; Gillard, Jonathan H.; Graves, Martin J.

    2017-05-01

    The paper reports a free-breathing black-blood CINE fast-spin echo (FSE) technique for measuring abdominal aortic wall motion. The free-breathing CINE FSE includes the following MR techniques: (1) variable-density sampling with fast iterative reconstruction; (2) inner-volume imaging; and (3) a blood-suppression preparation pulse. The proposed technique was evaluated in eight healthy subjects. The inner-volume imaging significantly reduced the intraluminal artifacts of respiratory motion (p  =  0.015). The quantitative measurements were a diameter of 16.3  ±  2.8 mm and wall distensibility of 2.0  ±  0.4 mm (12.5  ±  3.4%) and 0.7  ±  0.3 mm (4.1  ±  1.0%) for the anterior and posterior walls, respectively. The cyclic cross-sectional distensibility was 35  ±  15% greater in the systolic phase than in the diastolic phase. In conclusion, we developed a feasible CINE FSE method to measure the motion of the abdominal aortic wall, which will enable clinical scientists to study the elasticity of the abdominal aorta.

  3. A Swiss cheese error detection method for real-time EPID-based quality assurance and error prevention.

    Science.gov (United States)

    Passarge, Michelle; Fix, Michael K; Manser, Peter; Stampanoni, Marco F M; Siebers, Jeffrey V

    2017-04-01

    To develop a robust and efficient process that detects relevant dose errors (dose errors of ≥5%) in external beam radiation therapy and directly indicates the origin of the error. The process is illustrated in the context of electronic portal imaging device (EPID)-based angle-resolved volumetric-modulated arc therapy (VMAT) quality assurance (QA), particularly as would be implemented in a real-time monitoring program. A Swiss cheese error detection (SCED) method was created as a paradigm for a cine EPID-based during-treatment QA. For VMAT, the method compares a treatment plan-based reference set of EPID images with images acquired over each 2° gantry angle interval. The process utilizes a sequence of independent consecutively executed error detection tests: an aperture check that verifies in-field radiation delivery and ensures no out-of-field radiation; output normalization checks at two different stages; global image alignment check to examine if rotation, scaling, and translation are within tolerances; pixel intensity check containing the standard gamma evaluation (3%, 3 mm) and pixel intensity deviation checks including and excluding high dose gradient regions. Tolerances for each check were determined. To test the SCED method, 12 different types of errors were selected to modify the original plan. A series of angle-resolved predicted EPID images were artificially generated for each test case, resulting in a sequence of precalculated frames for each modified treatment plan. The SCED method was applied multiple times for each test case to assess the ability to detect introduced plan variations. To compare the performance of the SCED process with that of a standard gamma analysis, both error detection methods were applied to the generated test cases with realistic noise variations. Averaged over ten test runs, 95.1% of all plan variations that resulted in relevant patient dose errors were detected within 2° and 100% within 14° (error, determination of error

  4. Third party EPID with IGRT capability retrofitted onto an existing medical linear accelerator.

    Science.gov (United States)

    Odero, D O; Shimm, D S

    2009-07-01

    Radiation therapy requires precision to avoid unintended irradiation of normal organs. Electronic Portal Imaging Devices (EPIDs), can help with precise patient positioning for accurate treatment. EPIDs are now bundled with new linear accelerators, or they can be purchased from the Linac manufacturer for retrofit. Retrofitting a third party EPID to a linear accelerator can pose challenges. The authors describe a relatively inexpensive third party CCD camera-based EPID manufactured by TheraView (Cablon Medical B.V.), installed onto a Siemens Primus linear accelerator, and integrated with a Lantis record and verify system, an Oldelft simulator with Digital Therapy Imaging (DTI) unit, and a Philips ADAC Pinnacle treatment planning system (TPS). This system integrates well with existing equipment and its software can process DICOM images from other sources. The system provides a complete imaging system that eliminates the need for separate software for portal image viewing, interpretation, analysis, archiving, image guided radiation therapy and other image management applications. It can also be accessed remotely via safe VPN tunnels. TheraView EPID retrofit therefore presents an example of a less expensive alternative to linear accelerator manufacturers' proprietary EPIDs suitable for implementation in third world countries radiation therapy departments which are often faced with limited financial resources.

  5. SU-F-J-114: On-Treatment Imagereconstruction Using Transit Images of Treatment Beams Through Patient and Thosethrough Planning CT Images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H; Cho, S [KAIST, Yuseong-gu, Daejeon (Korea, Republic of); Cheong, K [Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Jung, J [East Carolina University Greenville, NC (United States); Jung, S [Samsung Medical Cener, Gangnam-gu, Seoul (Korea, Republic of); Kim, J [Yonsei Cancer Center, Seoul (Korea, Republic of); Yeo, I [Loma Linda University Medical Center, Loma Linda, CA (United States)

    2016-06-15

    Purpose: To reconstruct patient images at the time of radiation delivery using measured transit images of treatment beams through patient and calculated transit images through planning CT images. Methods: We hypothesize that the ratio of the measured transit images to the calculated images may provide changed amounts of the patient image between times of planning CT and treatment. To test, we have devised lung phantoms with a tumor object (3-cm diameter) placed at iso-center (simulating planning CT) and off-center by 1 cm (simulating treatment). CT images of the two phantoms were acquired; the image of the off-centered phantom, unavailable clinically, represents the reference on-treatment image in the image quality of planning CT. Cine-transit images through the two phantoms were also acquired in EPID from a non-modulated 6 MV beam when the gantry was rotated 360 degrees; the image through the centered phantom simulates calculated image. While the current study is a feasibility study, in reality our computational EPID model can be applicable in providing accurate transit image from MC simulation. Changed MV HU values were reconstructed from the ratio between two EPID projection data, converted to KV HU values, and added to the planning CT, thereby reconstructing the on-treatment image of the patient limited to the irradiated region of the phantom. Results: The reconstructed image was compared with the reference image. Except for local HU differences>200 as a maximum, excellent agreement was found. The average difference across the entire image was 16.2 HU. Conclusion: We have demonstrated the feasibility of a method of reconstructing on-treatment images of a patient using EPID image and planning CT images. Further studies will include resolving the local HU differences and investigation on the dosimetry impact of the reconstructed image.

  6. Verification of dose delivery for a prostate sIMRT treatment using a SLIC-EPID

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Mohammad [Department of Medical Physics, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan (Iran, Islamic Republic of)], E-mail: Mohammadi@umsha.ac.ir; Bezak, Eva; Reich, Paul [Department of Medical Physics, Royal Adelaide Hospital, Adelaide, SA 5000 (Australia); Department of Physics and Mathematical Physics, University of Adelaide, Adelaide, SA 5000 (Australia)

    2008-12-15

    The current work focuses on the verification of transmitted dose maps, measured using a scanning liquid ionization chamber-electronic portal imaging device (SLIC-EPID) for a typical step-and-shoot prostate IMRT treatment using an anthropomorphic phantom at anterior-posterior (A-P), and several non-zero gantry angles. The dose distributions measured using the SLIC-EPID were then compared with those calculated in the modelled EPID for each segment/subfield and also for the corresponding total fields using a gamma function algorithm with a distance to agreement and dose difference criteria of 2.54 mm and 3%, respectively.

  7. Improved workflow for quantification of left ventricular volumes and mass using free-breathing motion corrected cine imaging.

    Science.gov (United States)

    Cross, Russell; Olivieri, Laura; O'Brien, Kendall; Kellman, Peter; Xue, Hui; Hansen, Michael

    2016-02-25

    Traditional cine imaging for cardiac functional assessment requires breath-holding, which can be problematic in some situations. Free-breathing techniques have relied on multiple averages or real-time imaging, producing images that can be spatially and/or temporally blurred. To overcome this, methods have been developed to acquire real-time images over multiple cardiac cycles, which are subsequently motion corrected and reformatted to yield a single image series displaying one cardiac cycle with high temporal and spatial resolution. Application of these algorithms has required significant additional reconstruction time. The use of distributed computing was recently proposed as a way to improve clinical workflow with such algorithms. In this study, we have deployed a distributed computing version of motion corrected re-binning reconstruction for free-breathing evaluation of cardiac function. Twenty five patients and 25 volunteers underwent cardiovascular magnetic resonance (CMR) for evaluation of left ventricular end-systolic volume (ESV), end-diastolic volume (EDV), and end-diastolic mass. Measurements using motion corrected re-binning were compared to those using breath-held SSFP and to free-breathing SSFP with multiple averages, and were performed by two independent observers. Pearson correlation coefficients and Bland-Altman plots tested agreement across techniques. Concordance correlation coefficient and Bland-Altman analysis tested inter-observer variability. Total scan plus reconstruction times were tested for significant differences using paired t-test. Measured volumes and mass obtained by motion corrected re-binning and by averaged free-breathing SSFP compared favorably to those obtained by breath-held SSFP (r = 0.9863/0.9813 for EDV, 0.9550/0.9685 for ESV, 0.9952/0.9771 for mass). Inter-observer variability was good with concordance correlation coefficients between observers across all acquisition types suggesting substantial agreement. Both motion

  8. Cine-Club

    CERN Multimedia

    Cine-Club

    2013-01-01

    The CERN CineClub is a meeting point every Thursday for anyone who wants to discover, discuss, and appreciate cinema with people who are truly interested in the art of the moving image. In the actual context where downloading became easier than cooking an egg, one might wonder why bother when it can be watched on any computer. Well, cinema is not an individual activity. What the CineClub offers is a big screen with good quality image and sound. It also offers a careful selection, for allowing people to (re-)discover new and forgotten authors. Finally, it offers the opportunity for meeting people sharing a common interest. So come every Thursday, and see by yourself that watching films can actually be a real party! Every Thursday at 20 h 00 Council Chamber, 503/1-001 Programme June 2013 Science Fiction Cycle “Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution.” 6th June 2...

  9. Flow velocity and volume measurement of superior and inferior mesenteric artery with cine phase contrast magnetic resonance imaging

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Cooper, T.G.; Jenner, G.; Potchen, E.J.; Ishigaki, Takeo.

    1994-01-01

    The flow velocity and volume of the superior and inferior mesenteric arteries (SMA, IMA) were measured with cine phase contrast magnetic resonance (MR) imaging in five healthy volunteers. Each volunteer was first measured in a fasting state, and then one, two, and three hours after a meal. The average SMA flow volume of the volunteers was 230.3±46.8 ml/min (mean±standard error) during the fasting state, and 714.7±207.7 ml/min, 339.2±85.7 ml/min, and 263.8±21.0 ml/min, respectively, at one, two, and three hours postmeal. The increase at one hour postmeal was statistically significant (p<0.05). The corresponding flow measurements in the IMA were 63.1±11.2 ml/min, 67.6±11.2 ml/min, 57.9±8.6 ml/min, and 53.2±6.8 ml/min. These values do not represent a statistically significant flow volume change in the IMA. In all volunteers, the SMA volumetric flow increased the most one hour after the food challenge (72-400% relative to baseline). Diastolic velocity in the SMA increased significantly one hour postmeal, but systolic velocity did not change significantly. The IMA did not demonstrate a significant change in either systolic or diastolic velocity. The difference between the SMA and IMA in the way of reacting against the food challenge is thought to represent the difference between the requirements of small and large intestine for blood supply after the food challenge. These data demonstrate the possibility of this modality for the assessment of conditions such as chronic mesenteric ischemia. (author)

  10. CINE CLUB

    CERN Multimedia

    Ciné Club

    2009-01-01

    Main Auditorium CERN jeudi 17 décembre 2009 à 18 h 15 à l’Amphithéâtre principal du CERN (bâtiment 500)   Comme chaque année avant Noël, le CineClub du CERN est heureux d’inviter petits et grands à une projection gratuite du film   LE MONDE DE NEMO (FINDING NEMO) (USA, 2003, Andrew Stanton and Lee Unkrich)   Dans les eaux tropicales de la Grande Barrière de corail, un poisson-clown du nom de Marin mène une existence paisible avec son fils unique, Nemo. Redoutant l’océan et ses risques imprévisibles, il fait de son mieux pour protéger son fils. Comme tous les petits poissons de son âge, celui-ci rêve pourtant d’explorer les mystérieux récifs. Lorsque Nemo disparaît, Marin devient malgré lui le héros d’une qu&a...

  11. Cine club

    CERN Document Server

    Ciné club

    2010-01-01

    Monday 13 December 2010 at 18:30 / Lundi 13 Décembre 2010 à 18:30 CERN Main Auditorium / Amphithéâtre Principal Comme chaque année avant Noël, le CINE-CLUB du CERN est heureux d’inviter petits et grands à une projection gratuite du film.   Ponyo sur la falaise (Japon, 2008, Hayao Miyazaki) Le petit Sosuke vit avec sa mère sur une haute falaise surplombant la mer. Un beau jour, il découvre sur la plage caillouteuse Ponyo, une petite fille poisson. Ponyo est si fascinée par Sosuke et le monde terrestre que son désir le plus cher est de devenir un être humain. Mais Fujimoto, son magicien de père, n’est pas du tout d’accord avec cette idée et il la force à regagner les profondeurs de l’océan. Bien décidée à revoir Sosuke, Ponyo s’&...

  12. How to perform and interpret cine MR enterography.

    Science.gov (United States)

    Wnorowski, Amelia M; Guglielmo, Flavius F; Mitchell, Donald G

    2015-11-01

    Magnetic resonance (MR) enterography has become a fundamental tool for small bowel evaluation. Multiphasic cine imaging is a useful component of MR enterography evaluation because it provides functional information about bowel motility. Cine MR enterography can be used to evaluate for strictures and adhesions. Bowel motility evaluation has been shown to increase pathologic lesion detection in Crohn's disease and has been incorporated into disease activity scoring systems. Currently, cine MR enterography remains underutilized. The purpose of this article is to outline how to perform and interpret cine MR enterography. The authors describe how to perform a multiphasic balanced steady state free precession sequence using different MR systems and give practical advice on how to display and interpret the cine sequence. Sample cases illustrate how the cine sequence complements standard MR enterography evaluation with T2 -weighted, contrast-enhanced T1 -weighted, and diffusion-weighted imaging. © 2015 Wiley Periodicals, Inc.

  13. Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography. Comparison with cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Belge, Benedicte; Pasquet, Agnes; Vanoverschelde, Jean-Louis J.; Coche, Emmanuel; Gerber, Bernhard L.

    2006-01-01

    Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134±51 and 67±56 ml) were similar to those by MR (137±57 and 70±60 ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55±21 vs. 56±21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3±1.8 vs. 8.8±1.9 mm and 12.7±3.4 vs. 13.3±3.5 mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54±30 vs. 51±31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR. (orig.)

  14. Detection of diminished response to cold pressor test in smokers: assessment using phase-contrast cine magnetic resonance imaging of the coronary sinus.

    Science.gov (United States)

    Kato, Shingo; Kitagawa, Kakuya; Yoon, Yeonyee E; Nakajima, Hiroshi; Nagata, Motonori; Takase, Shinichi; Nakamori, Shiro; Ito, Masaaki; Sakuma, Hajime

    2014-04-01

    The purposes of this study were to evaluate the reproducibility for measuring the cold pressor test (CPT)-induced myocardial blood flow (MBF) alteration using phase-contrast (PC) cine MRI, and to determine if this approach could detect altered MBF response to CPT in smokers. After obtaining informed consent, ten healthy male non-smokers (mean age: 28±5 years) and ten age-matched male smokers (smoking duration ≥5 years, mean age: 28±3 years) were examined in this institutional review board approved study. Breath-hold PC cine MR images of the coronary sinus were obtained with a 3T MR imager with 32 channel coils at rest and during a CPT performed after immersing one foot in ice water. MBF was calculated as coronary sinus flow divided by the left ventricular (LV) mass which was given as a total LV myocardial volume measured on cine MRI multiplied by the specific gravity (1.05 g/mL). In non-smokers, MBF was 0.86±0.25 mL/min/g at rest, with a significant increase to 1.20±0.36 mL/min/g seen during CPT (percentage change of MBF (∆MBF (%)); 39.2%±14.4%, pcine MRI can be used to reproducibly quantify MBF response to CPT and to detect impaired flow response in smokers. This MR approach may be useful for monitoring the sequential change of coronary blood flow in various potentially pathologic conditions and for investigating its relationship with cardiovascular risk. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Clinical validation of an in-house EPID dosimetry system for IMRT QA at the Prince of Wales Hospital

    Science.gov (United States)

    Tyler, M.; Vial, P.; Metcalfe, P.; Downes, S.

    2013-06-01

    In this study a simple method using standard flood-field corrected Electronic Portal Imaging Device (EPID) images for routine Intensity Modulated Radiation Therapy (IMRT) Quality Assurance (QA) was investigated. The EPID QA system was designed and tested on a Siemens Oncor Impression linear accelerator with an OptiVue 1000ST EPID panel (Siemens Medical Solutions USA, Inc, USA) and an Elekta Axesse linear accelerator with an iViewGT EPID (Elekta AB, Sweden) for 6 and 10 MV IMRT fields with Step-and-Shoot and dynamic-MLC delivery. Two different planning systems were used for patient IMRT field generation for comparison with the measured EPID fluences. All measured IMRT plans had >95% agreement to the planning fluences (using 3 cGy / 3 mm Gamma Criteria) and were comparable to the pass-rates calculated using a 2-D diode array dosimeter.

  16. SIFT-based dense pixel tracking on 0.35 T cine-MR images acquired during image-guided radiation therapy with application to gating optimization.

    Science.gov (United States)

    Mazur, Thomas R; Fischer-Valuck, Benjamin W; Wang, Yuhe; Yang, Deshan; Mutic, Sasa; Li, H Harold

    2016-01-01

    To first demonstrate the viability of applying an image processing technique for tracking regions on low-contrast cine-MR images acquired during image-guided radiation therapy, and then outline a scheme that uses tracking data for optimizing gating results in a patient-specific manner. A first-generation MR-IGRT system-treating patients since January 2014-integrates a 0.35 T MR scanner into an annular gantry consisting of three independent Co-60 sources. Obtaining adequate frame rates for capturing relevant patient motion across large fields-of-view currently requires coarse in-plane spatial resolution. This study initially (1) investigate the feasibility of rapidly tracking dense pixel correspondences across single, sagittal plane images (with both moderate signal-to-noise and spatial resolution) using a matching objective for highly descriptive vectors called scale-invariant feature transform (SIFT) descriptors associated to all pixels that describe intensity gradients in local regions around each pixel. To more accurately track features, (2) harmonic analysis was then applied to all pixel trajectories within a region-of-interest across a short training period. In particular, the procedure adjusts the motion of outlying trajectories whose relative spectral power within a frequency bandwidth consistent with respiration (or another form of periodic motion) does not exceed a threshold value that is manually specified following the training period. To evaluate the tracking reliability after applying this correction, conventional metrics-including Dice similarity coefficients (DSCs), mean tracking errors (MTEs), and Hausdorff distances (HD)-were used to compare target segmentations obtained via tracking to manually delineated segmentations. Upon confirming the viability of this descriptor-based procedure for reliably tracking features, the study (3) outlines a scheme for optimizing gating parameters-including relative target position and a tolerable margin about this

  17. SIFT-based dense pixel tracking on 0.35 T cine-MR images acquired during image-guided radiation therapy with application to gating optimization

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, Thomas R., E-mail: tmazur@radonc.wustl.edu, E-mail: hli@radonc.wustl.edu; Fischer-Valuck, Benjamin W.; Wang, Yuhe; Yang, Deshan; Mutic, Sasa; Li, H. Harold, E-mail: tmazur@radonc.wustl.edu, E-mail: hli@radonc.wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 (United States)

    2016-01-15

    Purpose: To first demonstrate the viability of applying an image processing technique for tracking regions on low-contrast cine-MR images acquired during image-guided radiation therapy, and then outline a scheme that uses tracking data for optimizing gating results in a patient-specific manner. Methods: A first-generation MR-IGRT system—treating patients since January 2014—integrates a 0.35 T MR scanner into an annular gantry consisting of three independent Co-60 sources. Obtaining adequate frame rates for capturing relevant patient motion across large fields-of-view currently requires coarse in-plane spatial resolution. This study initially (1) investigate the feasibility of rapidly tracking dense pixel correspondences across single, sagittal plane images (with both moderate signal-to-noise and spatial resolution) using a matching objective for highly descriptive vectors called scale-invariant feature transform (SIFT) descriptors associated to all pixels that describe intensity gradients in local regions around each pixel. To more accurately track features, (2) harmonic analysis was then applied to all pixel trajectories within a region-of-interest across a short training period. In particular, the procedure adjusts the motion of outlying trajectories whose relative spectral power within a frequency bandwidth consistent with respiration (or another form of periodic motion) does not exceed a threshold value that is manually specified following the training period. To evaluate the tracking reliability after applying this correction, conventional metrics—including Dice similarity coefficients (DSCs), mean tracking errors (MTEs), and Hausdorff distances (HD)—were used to compare target segmentations obtained via tracking to manually delineated segmentations. Upon confirming the viability of this descriptor-based procedure for reliably tracking features, the study (3) outlines a scheme for optimizing gating parameters—including relative target position and a

  18. Evaluation of manual and automatic segmentation of the mouse heart from CINE MR images

    NARCIS (Netherlands)

    Heijman, Edwin; Aben, Jean-Paul; Penners, Cindy; Niessen, Petra; Guillaume, René; van Eys, Guillaume; Nicolay, Klaas; Strijkers, Gustav J.

    2008-01-01

    To compare global functional parameters determined from a stack of cinematographic MR images of mouse heart by a manual segmentation and an automatic segmentation algorithm. The manual and automatic segmentation results of 22 mouse hearts were compared. The automatic segmentation was based on

  19. Quality considerations on cine-imaging and PTCA-fluoroscopy anticipating a digital future

    International Nuclear Information System (INIS)

    Leeuw, P. de

    1986-01-01

    In a modern catheterization laboratory coronary cineangiography, PTCA procedures and digital radiography are performed with one and the same X-ray system. On the basis of an optimization analysis of the image quality using the concepts of window signal-to-noise ratio and equivalent blur, overall performance can roughly be estimated. Some important aspects of a realistic X-ray system design resulting from this analysis have been identified. Specifically, the X-ray loadability and its loading strategy play a crucial role with respect to signal detection sensitivity and the safe, efficient use of X-ray radiation. The analysis shows also that some basic limitations exist to the use of digital subtraction techniques for moving objects. Last but not least, it shows that the video camera performance is critical with respect to the imaging tasks during PTCA and digital procedures. (Auth.)

  20. Cardiac phase-specific shimming (CPSS) for SSFP MR cine imaging at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Kubach, Miriam R; Bornstedt, Axel; Hombach, Vinzenz; Merkle, Nico; Spiess, Jochen; Rasche, Volker [Department of Internal Medicine II, University Hospital Ulm, Robert-Koch-Str. 8, 89081 Ulm (Germany); Schaer, Michael [Department of Radiology, Johns Hopkins University, 600N. Wolf Street, Baltimore, MD 21287 (United States); Nienhaus, Gerd U [Institute of Biophysics, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm (Germany)], E-mail: volker.rasche@uniklinik-ulm.de

    2009-10-21

    The application of steady-state-free-precession (SSFP) techniques at 3 T systems is still limited by their sensitivity to magnetic field inhomogeneities. Especially during imaging of the heart, the arising signal voids and distortions in the myocardium currently often limit the diagnostic value of the resulting images. Dedicated shim systems providing higher order shimming capabilities have been applied to improve the field homogeneity across the heart. In this study, the potential benefit of applying a cardiac phase-specific shim (CPSS) was investigated. The cardiac phase dependence of the magnetic field distortions over the heart was assessed and the potential gain in field homogeneity by CPSS was evaluated. CPSS was successfully applied in volunteers and yielded significant improvement in the main magnetic field homogeneity over the entire cardiac cycle. (note)

  1. An EPID based method for efficient and precise asymmetric jaw alignment quality assurance

    International Nuclear Information System (INIS)

    Clews, Luke; Greer, Peter B.

    2009-01-01

    Purpose: The aim of this work was to investigate the use of amorphous silicon electronic portal imaging devices (EPIDs) for regular quality assurance of linear accelerator asymmetric jaw junctioning. Methods: The method uses the beam central axis position on the EPID measured to subpixel accuracy found from two EPID images with 180 degree sign opposing collimator angles. Individual zero jaw position (''half-beam blocked'') images are then acquired and the jaw position precisely determined for each using penumbra interpolation. The accuracy of determining jaw position with the EPID method was measured by translating a block (simulating a jaw) by known distances, using a translation stage, and then measuring each translation distance with the EPID. To establish the utility of EPID based junction dose measurements, radiographic film measurements of junction dose maxima/minima as a function of jaw gap/overlap were made and compared to EPID measurements. Using the method, the long-term stability of zero jaw positioning was assessed for four linear accelerators over a 1-1.5 yr time period. The stability at nonzero gantry angles was assessed over a shorter time period. Results: The accuracy of determining jaw translations with the method was within 0.14 mm found using the translation stage [standard deviation (SD) of 0.037 mm]. The junction doses measured with the EPID were different from film due to the nonwater equivalent EPID scattering properties and hence different penumbra profile. The doses were approximately linear with gap or overlap, and a correction factor was derived to convert EPID measured junction dose to film measured equivalent. Over a 1 yr period, the zero jaw positions at gantry zero position were highly reproducible with an average SD of 0.07 mm for the 16 collimator jaws examined. However, the average jaw positions ranged from -0.7 to 0.9 mm relative to central axis for the different jaws. The zero jaw position was also reproducible at gantry 90

  2. Vortex Flow in the Right Atrium Surrogates Supraventricular Arrhythmia and Thrombus After Atriopulmonary Connection-Type Fontan Operation: Vortex Flow Analysis Using Conventional Cine Magnetic Resonance Imaging.

    Science.gov (United States)

    Shiina, Yumi; Inai, Kei; Takahashi, Tatsunori; Shimomiya, Yamato; Ishizaki, Umiko; Fukushima, Kenji; Nagao, Michinobu

    2018-02-01

    We developed a novel imaging technique, designated as vortex flow (VF) mapping, which presents a vortex flow visually on conventional two-dimensional (2D) cine MRI. Using it, we assessed circumferential VF patterns and influences on RA thrombus and supraventricular tachycardia (SVT) in AP connection-type Fontan circulation. Retrospectively, we enrolled 27 consecutive patients (25.1 ± 9.2 years) and 7 age-matched controls who underwent cardiac MRI. Conventional cine images acquired using a 1.5-Tesla scanner were scanned for axial and coronal cross section of the RA. We developed "vortex flow mapping" to demonstrate the ratio of the circumferential voxel movement at each phase to the total movement throughout a cardiac cycle towards the RA center. The maximum ratio was used as a magnitude of vortex flow (MVF%) in RA cine imaging. We also measured percentages of strong and weak VF areas (VFA%). Furthermore, in 10 out of 27, we compared VF between previous CMR (3.8 ± 1.5 years ago) and latest CMR. Of the patients, 15 had cardiovascular complications (Group A); 12 did not (Group B). A transaxial image showed that strong VFA% in Group A was significantly smaller than that in Group B or controls. A coronal view revealed that strong VFA% was also smaller, and weak VFA% was larger in Group A than in Group B or controls (P < 0.05, and P < 0.05). Maximum MVF% in Group A was significantly smaller than in other groups (P < 0.001). Univariate logistic analyses revealed weak VFA% on a coronal image, and serum total bilirubin level as factors affecting cardiovascular complications (Odds ratio 1.14 and 66.1, 95% CI 1.004-1.30 and 1.59-2755.6, P values < 0.05 and < 0.05, respectively). Compared to the previous CMR, smaller maximum VMF%, smaller strong VFA%, and larger weak VFA% were identified in the latest CMR. Circumferentially weak VFA% on a coronal image can be one surrogate marker of SVT and thrombus in AP connection-type Fontan circulation. This simple VF

  3. Single breath-hold magnetic resonance cine imaging for fast assessment of global and regional left ventricular function in clinical routine

    International Nuclear Information System (INIS)

    Nassenstein, Kai; Heilmaier, Christina; Schlosser, Thomas; Eberle, Holger; Jensen, Christoph J.; Bruder, Oliver; Maderwald, Stefan

    2010-01-01

    To evaluate a TGRAPPA (temporal parallel acquisition technique)-accelerated, single breath-hold multi-slice cine imaging approach for the assessment of left ventricular (LV) function. One hundred eleven patients were examined at 1.5 T. Cine imaging was performed with single-slice breath-hold acquisitions in short-axis orientation using a SSFP (TR 2.63 ms, TE 1.12 ms, FA 72 ) sequence and a TGRAPPA SSFP (TR 2.66 ms, TE 1.11 ms, FA 72 , AF 3) sequence, which covered the entire LV in multiple short-axis slices during a single breath-hold. End-diastolic (EDV), end-systolic (ESV), stroke volumes (SV), ejection fraction (EF), muscle mass (MM) and regional wall motion were assessed for both data sets. Single breath-hold imaging was feasible in 108 patients. Excellent correlations were observed for all volumetric parameters derived from both data sets (all r > 0.97). While EDV and ESV showed marginally lower values for single breath-hold imaging (EDV: -1.6 ± 7.9 ml; ESV: -1.8 ± 6.0 ml, p < 0.05), no differences were observed for SV, EF, MM and regional wall motion assessment. Single breath-hold imaging required significant shorter acquisition times (28 ± 6 s vs. 335 ± 87 s). TGRAPPA-accelerated multi-slice SSPF imaging allows for fast and accurate assessment of regional and global LV function within a single breath-hold. (orig.)

  4. El silencio del monstruo: imagénes espectrales en el cine de terror americano de comienzos del sonoro / Silence of the Monster. Ghostly Images in American Horror Film at the Beginning of Sound

    Directory of Open Access Journals (Sweden)

    Roberto Cueto

    2016-09-01

    Full Text Available Drácula y El doctor Frankenstein inauguraron en 1931 la producción de cine de terror en el cine sonoro al presentar a dos de los iconos por excelencia del género. Sin embargo, al ser películas producidas en el período de transición del cine mudo al sonoro, hacen gala de una característica especial que las diferencia notablemente de la posterior producción terrorífica de Hollywood: la presentación de la monstruosidad sin el recurso de la música extradiegética, lo que genera en la narración un efecto de «agujero» de silencio. En posteriores producciones de cine de terror se intentará paliar estos lapsos de silencio con el empleo de la música extradiegética o ciertos efectos de sonido, lo que parece indicar que, para la norma del cine clásico americano, eran defectos que debían ser corregidos. El siguiente ensayo tiene como objeto subrayar cómo esa llamativa presencia del silencio confiere a la representación de la monstruosidad cierta cualidad de «imágenes espectrales» o «cuerpos siniestros» que el cine de Hollywood prefirió evitar. Por otra parte, se analizará también por qué fue tan importante para el cine clásico americano el empleo de la música extradiegética, ya que cumplía una serie de funciones necesarias para sus estrategias narrativas: una mayor implicación del espectador, una adscripción a los códigos del género terrorífico y un efecto de «tridimensionalidad» aplicado a las imágenes bidimensionales.Palabras clave: música cinematográfica, cine de terror, sonido cinematográfico, transición del cine mudo al sonoro.AbstractDracula and Frankenstein, both released in 1931, inaugurated the production of horror films in Hollywood when they presented the two greatest icons of the genre. As films produced in the transitional period from silent to sound film, both showcase special features that distinguished them from posterior horror films in Hollywood: the introduction of the monstrosity without

  5. Characterization of the a-Si EPID in the unity MR-linac for dosimetric applications

    Science.gov (United States)

    Torres-Xirau, I.; Olaciregui-Ruiz, I.; Baldvinsson, G.; Mijnheer, B. J.; van der Heide, U. A.; Mans, A.

    2018-01-01

    Electronic portal imaging devices (EPIDs) are frequently used in external beam radiation therapy for dose verification purposes. The aim of this study was to investigate the dose-response characteristics of the EPID in the Unity MR-linac (Elekta AB, Stockholm, Sweden) relevant for dosimetric applications under clinical conditions. EPID images and ionization chamber (IC) measurements were used to study the effects of the magnetic field, the scatter generated in the MR housing reaching the EPID, and inhomogeneous attenuation from the MR housing. Dose linearity and dose rate dependencies were also determined. The magnetic field strength at EPID level did not exceed 10 mT, and dose linearity and dose rate dependencies proved to be comparable to that on a conventional linac. Profiles of fields, delivered with and without the magnetic field, were indistinguishable. The EPID center had an offset of 5.6 cm in the longitudinal direction, compared to the beam central axis, meaning that large fields in this direction will partially fall outside the detector area and not be suitable for verification. Beam attenuation by the MRI scanner and the table is gantry angle dependent, presenting a minimum attenuation of 67% relative to the 90° measurement. Repeatability, observed over two months, was within 0.5% (1 SD). In order to use the EPID for dosimetric applications in the MR-linac, challenges related to the EPID position, scatter from the MR housing, and the inhomogeneous, gantry angle-dependent attenuation of the beam will need to be solved.

  6. Determination of left and right ventricular ejection and filling by fast cine MR imaging in the breath-hold technique in healthy subjects

    International Nuclear Information System (INIS)

    Rominger, M.B.; Bachmann, G.F.; Geuer, M.; Puzik, M.; Rau, W.S.; Pabst, W.

    1999-01-01

    Purpose: Evaluation and comparison of localized and global left and right ventricular ejection and filling with fast cine MR imaging in the breath-hold technique. Materials and Methods: 10 healthy volunteers were examined with a 1.5 Tesla unit and phased-array-coil using a segmented FLASH-2D sequence in breath-hold technique. Peak ejection and peak filling rates [PER, PFR enddiastolic volume (EDV)/s], time to PER and PFR [TPER, TPFR ms] and time of endsystole [TSYS in % RR-intervall] of all slices (complete-slice-evaluation) were evaluated and compared to three left ventricular and one right ventricular slices (reduced three-slice-evaluation). Results: There were significant regional left ventricular differences of PER (p=0.002) and PFR (p=0.007), but not of TPER and TPFR. Ejection and filling indices of the left ventricular middle slice were closest to the overall evaluation of all sections. In the left-/right-side comparison the right ventricular PFR was higher than the left ventricular (5.1 and 4.2 EDV/s) and the right ventricular TPFR was earlier than the left (92.2 and 123.5 ms). Conclusions: With fast cine techniques, regional and global left and right ventricular ejection and filling indices can be evaluated in addition to the global heart volume indices. The three-slice-evaluation represents a comprehensive, clear and time-saving method for daily routine. (orig.) [de

  7. Daily QA of linear accelerators using only EPID and OBI.

    Science.gov (United States)

    Sun, Baozhou; Goddu, S Murty; Yaddanapudi, Sridhar; Noel, Camille; Li, Hua; Cai, Bin; Kavanaugh, James; Mutic, Sasa

    2015-10-01

    As treatment delivery becomes more complex, there is a pressing need for robust quality assurance (QA) tools to improve efficiency and comprehensiveness while simultaneously maintaining high accuracy and sensitivity. This work aims to present the hardware and software tools developed for comprehensive QA of linear accelerator (LINAC) using only electronic portal imaging devices (EPIDs) and kV flat panel detectors. A daily QA phantom, which includes two orthogonally positioned phantoms for QA of MV-beams and kV onboard imaging (OBI) is suspended from the gantry accessory holder to test both geometric and dosimetric components of a LINAC and an OBI. The MV component consists of a 0.5 cm water-equivalent plastic sheet incorporating 11 circular steel plugs for transmission measurements through multiple thicknesses and one resolution plug for MV-image quality testing. The kV-phantom consists of a Leeds phantom (TOR-18 FG phantom supplied by Varian) for testing low and high contrast resolutions. In the developed process, the existing LINAC tools were used to automate daily acquisition of MV and kV images and software tools were developed for simultaneous analysis of these images. A method was developed to derive and evaluate traditional QA parameters from these images [output, flatness, symmetry, uniformity, TPR20/10, and positional accuracy of the jaws and multileaf collimators (MLCs)]. The EPID-based daily QA tools were validated by performing measurements on a detuned 6 MV beam to test its effectiveness in detecting errors in output, symmetry, energy, and MLC positions. The developed QA process was clinically commissioned, implemented, and evaluated on a Varian TrueBeam LINAC (Varian Medical System, Palo Alto, CA) over a period of three months. Machine output constancy measured with an EPID (as compared against a calibrated ion-chamber) is shown to be within ±0.5%. Beam symmetry and flatness deviations measured using an EPID and a 2D ion-chamber array agree within

  8. Dosimetric characterization of an a-based EPID for quality control if patient-specific IMRT

    International Nuclear Information System (INIS)

    Larrinaga Cortina, Eduardo Francisco; Alfonso Laguardia, Rodolfo; Silvestre Patallo, Ileana; Garcia Yip, Fernando

    2009-01-01

    The Electronic portal imaging devices, EPID for its acronym in English is a technology widely used for verification of patient positioning on linear accelerators routinely. Its use as a dosimetry device is not as widespread, although many researches in this field. It assessed the availability and versatility of the use EPID based on an amorphous silicon (a-Si) as a means of quality control specific patient for a methodology of Radiation Intensity Modulated IMRT. Dosimetric parameters were determined for the linearity of dose versus response, dispersion and sensitivity factors off-axis radiation. For absolute measurements the linearity of the dose-response relationship EPID was better than 1.1 and 1.5% for photon beams of 6 and 15mV respectively, in the range from 2 to 500 UM. The dose dependence with field size was studied and compared with the factors of dispersion in water at different depths, in agreement with those measured at 5 cm depth, Scp (z = 5cm). Off-axis sensitivity of the EPID was determined by comparing the measured profiles versus the same profiles at different depths in water. The best correspondence was observed at 5 cm depth, where the EPID response underestimates the dose to 4% for all sizes of fields in the plateau area. The EPID can be used for the evaluation of dosimetric parameters of the beam at a specific depth in water of 5 cm and a discrepancy in an acceptable maximum rate of 4%. (author)

  9. Image-guided radiotherapy in near real time with intensity-modulated radiotherapy megavoltage treatment beam imaging.

    Science.gov (United States)

    Mao, Weihua; Hsu, Annie; Riaz, Nadeem; Lee, Louis; Wiersma, Rodney; Luxton, Gary; King, Christopher; Xing, Lei; Solberg, Timothy

    2009-10-01

    To utilize image-guided radiotherapy (IGRT) in near real time by obtaining and evaluating the online positions of implanted fiducials from continuous electronic portal imaging device (EPID) imaging of prostate intensity-modulated radiotherapy (IMRT) delivery. Upon initial setup using two orthogonal images, the three-dimensional (3D) positions of all implanted fiducial markers are obtained, and their expected two-dimensional (2D) locations in the beam's-eye-view (BEV) projection are calculated for each treatment field. During IMRT beam delivery, EPID images of the megavoltage treatment beam are acquired in cine mode and subsequently analyzed to locate 2D locations of fiducials in the BEV. Simultaneously, 3D positions are estimated according to the current EPID image, information from the setup portal images, and images acquired at other gantry angles (the completed treatment fields). The measured 2D and 3D positions of each fiducial are compared with their expected 2D and 3D setup positions, respectively. Any displacements larger than a predefined tolerance may cause the treatment system to suspend the beam delivery and direct the therapists to reposition the patient. Phantom studies indicate that the accuracy of 2D BEV and 3D tracking are better than 1 mm and 1.4 mm, respectively. A total of 7330 images from prostate treatments were acquired and analyzed, showing a maximum 2D displacement of 6.7 mm and a maximum 3D displacement of 6.9 mm over 34 fractions. This EPID-based, real-time IGRT method can be implemented on any external beam machine with portal imaging capabilities without purchasing any additional equipment, and there is no extra dose delivered to the patient.

  10. Accuracy and effectiveness of self-gating signals in free-breathing three-dimensional cardiac cine magnetic resonance imaging

    Science.gov (United States)

    Li, Shuo; Wang, Lei; Zhu, Yan-Chun; Yang, Jie; Xie, Yao-Qin; Fu, Nan; Wang, Yi; Gao, Song

    2016-12-01

    Conventional multiple breath-hold two-dimensional (2D) balanced steady-state free precession (SSFP) presents many difficulties in cardiac cine magnetic resonance imaging (MRI). Recently, a self-gated free-breathing three-dimensional (3D) SSFP technique has been proposed as an alternative in many studies. However, the accuracy and effectiveness of self-gating signals have been barely studied before. Since self-gating signals are crucially important in image reconstruction, a systematic study of self-gating signals and comparison with external monitored signals are needed. Previously developed self-gated free-breathing 3D SSFP techniques are used on twenty-eight healthy volunteers. Both electrocardiographic (ECG) and respiratory bellow signals are also acquired during the scan as external signals. Self-gating signal and external signal are compared by trigger and gating window. Gating window is proposed to evaluate the accuracy and effectiveness of respiratory self-gating signal. Relative deviation of the trigger and root-mean-square-deviation of the cycle duration are calculated. A two-tailed paired t-test is used to identify the difference between self-gating and external signals. A Wilcoxon signed rank test is used to identify the difference between peak and valley self-gating triggers. The results demonstrate an excellent correlation (P = 0, R > 0.99) between self-gating and external triggers. Wilcoxon signed rank test shows that there is no significant difference between peak and valley self-gating triggers for both cardiac (H = 0, P > 0.10) and respiratory (H = 0, P > 0.44) motions. The difference between self-gating and externally monitored signals is not significant (two-tailed paired-sample t-test: H = 0, P > 0.90). The self-gating signals could demonstrate cardiac and respiratory motion accurately and effectively as ECG and respiratory bellow. The difference between the two methods is not significant and can be explained. Furthermore, few ECG trigger errors

  11. Control of an X-ray cine radiography apparatus

    International Nuclear Information System (INIS)

    Nishio, K.

    1982-01-01

    This patent application describes an X-ray cine radiography apparatus comprising an X-ray tube, an image intensifier for converting the X-rays transmitted through an object into a visual image and a cine camera for picking up the visual image, a photomultiplier detects the brightness of the visual image to produce a brightness signal and a potentiometer detects the actual tube voltage of said X-ray tube. (author)

  12. Physiological Uptake of 18F-Fluorodeoxyglucose in Uterine Endometrium and Myometrium: Correlation with Uterine Motility Evaluated by Cine Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kido, A.; Nishizawa, S.; Okada, H. (Hamamatsu Medical Imaging Center, Hamamatsu Medical Photonics Foundation, Hamakita City, Shizuoka (Japan)); Nakamoto, Y.; Yamamoto, A.; Fujimoto, K.; Togashi, K. Dept. of Diagnostic Radiology, Kyoto Univ. Hospital, Kyoto City, Kyoto (Japan))

    2009-05-15

    Background: Accumulation of 18F-fluorodeoxyglucose (18F-FDG) in the uterine endometrium and uterine motility are dependent on menstrual cycle. However, the relationship between them remains unknown. Purpose: To investigate the relationship between radiometabolic activity of 18F-FDG in the uterus and uterine motility observed by cine magnetic resonance imaging (MRI). Material and Methods: The study population consisted of 65 healthy, fertile women, selected from 229 women who underwent positron emission tomography (PET), computed tomography (CT), and MRI for cancer screening at our facility. They were divided into three groups according to their menstrual cycle phases: menstrual, follicular-periovulatory, and luteal. Regions of interest (ROIs) were placed over the endometrium and myometrium to calculate the standardized uptake value (SUV). Uterine peristalsis and contraction shown by cine MR imaging were evaluated visually, and the correlation between FDG uptake and uterine movements was assessed. Results: After excluding nine patients due to inadequate images, 56 patients (19 follicular-periovulatory, 27 luteal, and 10 menstrual) were analyzed. FDG uptake of the endometrium, frequency of peristalsis, and the presence of sustained contraction varied according to the menstruation cycle, with a tendency toward greater uptake in the menstrual phase, but there was little relationship between the frequency of uterine peristalsis and FDG accumulation in the uterus. Significantly higher FDG accumulation in the endometrium was observed in patients with sustained contractions (3.32+-1.47) than in those without contractions (2.45+-0.66). Conclusion: Our preliminary data suggest that FDG accumulation in the endometrium tends to be higher in patients with uterine contraction, although there was no significant correlation between uterine peristalsis and FDG uptake in the uterine myometrium or endometrium

  13. Physiological Uptake of 18F-Fluorodeoxyglucose in Uterine Endometrium and Myometrium: Correlation with Uterine Motility Evaluated by Cine Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Kido, A.; Nishizawa, S.; Okada, H.; Nakamoto, Y.; Yamamoto, A.; Fujimoto, K.; Togashi, K.

    2009-01-01

    Background: Accumulation of 18 F-fluorodeoxyglucose ( 18 F-FDG) in the uterine endometrium and uterine motility are dependent on menstrual cycle. However, the relationship between them remains unknown. Purpose: To investigate the relationship between radiometabolic activity of 18 F-FDG in the uterus and uterine motility observed by cine magnetic resonance imaging (MRI). Material and Methods: The study population consisted of 65 healthy, fertile women, selected from 229 women who underwent positron emission tomography (PET), computed tomography (CT), and MRI for cancer screening at our facility. They were divided into three groups according to their menstrual cycle phases: menstrual, follicular-periovulatory, and luteal. Regions of interest (ROIs) were placed over the endometrium and myometrium to calculate the standardized uptake value (SUV). Uterine peristalsis and contraction shown by cine MR imaging were evaluated visually, and the correlation between FDG uptake and uterine movements was assessed. Results: After excluding nine patients due to inadequate images, 56 patients (19 follicular-periovulatory, 27 luteal, and 10 menstrual) were analyzed. FDG uptake of the endometrium, frequency of peristalsis, and the presence of sustained contraction varied according to the menstruation cycle, with a tendency toward greater uptake in the menstrual phase, but there was little relationship between the frequency of uterine peristalsis and FDG accumulation in the uterus. Significantly higher FDG accumulation in the endometrium was observed in patients with sustained contractions (3.32±1.47) than in those without contractions (2.45±0.66). Conclusion: Our preliminary data suggest that FDG accumulation in the endometrium tends to be higher in patients with uterine contraction, although there was no significant correlation between uterine peristalsis and FDG uptake in the uterine myometrium or endometrium

  14. Comparison of left ventricular function assessment using phonocardiogram- and electrocardiogram-triggered 2D SSFP CINE MR imaging at 1.5 T and 3.0 T

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Meike [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Humboldt-University, Experimental and Clinical Research Center (ECRC), Charite Campus Buch, Berlin (Germany); Frauenrath, Tobias; Hezel, Fabian [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin (Germany); Krombach, Gabriele A.; Kremer, Ute; Koppers, Benedikt [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Butenweg, Christoph; Goemmel, Andreas [Chair of Structural Statics and Dynamics, RWTH Aachen, Aachen (Germany); Utting, Jane F. [MRI, NHS Grampian, Aberdeen Royal Infirmary, Aberdeen (United Kingdom); Schulz-Menger, Jeanette [Humboldt-University, Working Group Cardiovascular MR, Franz-Volhard-Klinik, Department of Cardiology, HELIOS-Klinikum Berlin-Buch and Charite Campus Buch, Berlin (Germany); Niendorf, Thoralf [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Humboldt-University, Experimental and Clinical Research Center (ECRC), Charite Campus Buch, Berlin (Germany); Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin (Germany)

    2010-06-15

    As high-field cardiac MRI (CMR) becomes more widespread the propensity of ECG to interference from electromagnetic fields (EMF) and to magneto-hydrodynamic (MHD) effects increases and with it the motivation for a CMR triggering alternative. This study explores the suitability of acoustic cardiac triggering (ACT) for left ventricular (LV) function assessment in healthy subjects (n = 14). Quantitative analysis of 2D CINE steady-state free precession (SSFP) images was conducted to compare ACT's performance with vector ECG (VCG). Endocardial border sharpness (EBS) was examined paralleled by quantitative LV function assessment. Unlike VCG, ACT provided signal traces free of interference from EMF or MHD effects. In the case of correct R-wave recognition, VCG-triggered 2D CINE SSFP was immune to cardiac motion effects - even at 3.0 T. However, VCG-triggered 2D SSFP CINE imaging was prone to cardiac motion and EBS degradation if R-wave misregistration occurred. ACT-triggered acquisitions yielded LV parameters (end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF) and left ventricular mass (LVM)) comparable with those derived from VCG-triggered acquisitions (1.5 T: ESV{sub VCG} = (56 {+-} 17) ml, EDV{sub VCG} = (151 {+-} 32) ml, LVM{sub VCG} = (97 {+-} 27) g, SV{sub VCG} = (94 {+-} 19) ml, EF{sub VCG} = (63 {+-} 5)% cf. ESV{sub ACT} = (56 {+-} 18) ml, EDV{sub ACT} = (147 {+-} 36) ml, LVM{sub ACT} = (102 {+-} 29) g, SV{sub ACT} = (91 {+-} 22) ml, EF{sub ACT} = (62 {+-} 6)%; 3.0 T: ESV{sub VCG} = (55 {+-} 21) ml, EDV{sub VCG} = (151 {+-} 32) ml, LVM{sub VCG} = (101 {+-} 27) g, SV{sub VCG} = (96 {+-} 15) ml, EF{sub VCG} = (65 {+-} 7)% cf. ESV{sub ACT} = (54 {+-} 20) ml, EDV{sub ACT} = (146 {+-} 35) ml, LVM{sub ACT} = (101 {+-} 30) g, SV{sub ACT} = (92 {+-} 17) ml, EF{sub ACT} = (64 {+-} 6)%). ACT's intrinsic insensitivity to interference from electromagnetic fields renders it suitable for clinical CMR. (orig.)

  15. Comparison of left ventricular function assessment using phonocardiogram- and electrocardiogram-triggered 2D SSFP CINE MR imaging at 1.5 T and 3.0 T

    International Nuclear Information System (INIS)

    Becker, Meike; Frauenrath, Tobias; Hezel, Fabian; Krombach, Gabriele A.; Kremer, Ute; Koppers, Benedikt; Butenweg, Christoph; Goemmel, Andreas; Utting, Jane F.; Schulz-Menger, Jeanette; Niendorf, Thoralf

    2010-01-01

    As high-field cardiac MRI (CMR) becomes more widespread the propensity of ECG to interference from electromagnetic fields (EMF) and to magneto-hydrodynamic (MHD) effects increases and with it the motivation for a CMR triggering alternative. This study explores the suitability of acoustic cardiac triggering (ACT) for left ventricular (LV) function assessment in healthy subjects (n = 14). Quantitative analysis of 2D CINE steady-state free precession (SSFP) images was conducted to compare ACT's performance with vector ECG (VCG). Endocardial border sharpness (EBS) was examined paralleled by quantitative LV function assessment. Unlike VCG, ACT provided signal traces free of interference from EMF or MHD effects. In the case of correct R-wave recognition, VCG-triggered 2D CINE SSFP was immune to cardiac motion effects - even at 3.0 T. However, VCG-triggered 2D SSFP CINE imaging was prone to cardiac motion and EBS degradation if R-wave misregistration occurred. ACT-triggered acquisitions yielded LV parameters (end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF) and left ventricular mass (LVM)) comparable with those derived from VCG-triggered acquisitions (1.5 T: ESV VCG = (56 ± 17) ml, EDV VCG = (151 ± 32) ml, LVM VCG = (97 ± 27) g, SV VCG = (94 ± 19) ml, EF VCG = (63 ± 5)% cf. ESV ACT = (56 ± 18) ml, EDV ACT = (147 ± 36) ml, LVM ACT = (102 ± 29) g, SV ACT = (91 ± 22) ml, EF ACT = (62 ± 6)%; 3.0 T: ESV VCG = (55 ± 21) ml, EDV VCG = (151 ± 32) ml, LVM VCG = (101 ± 27) g, SV VCG = (96 ± 15) ml, EF VCG = (65 ± 7)% cf. ESV ACT = (54 ± 20) ml, EDV ACT = (146 ± 35) ml, LVM ACT = (101 ± 30) g, SV ACT = (92 ± 17) ml, EF ACT = (64 ± 6)%). ACT's intrinsic insensitivity to interference from electromagnetic fields renders it suitable for clinical CMR. (orig.)

  16. Application of cine MRI-tagging method to aortic dessection

    International Nuclear Information System (INIS)

    Yoshioka, Kunihiro; Takahashi, Tsuneo; Kamata, Hiroyuki; Kikuchi, Kenichi; Yamaguchi, Kojiro.

    1992-01-01

    For the evaluation of aortic dissection, ECG-gated SE or cine MR imaging has been usually performed. However, detection of slow flow in the false lumen and differentiation between mural thrombus and slow flow are sometimes difficult. Because paradoxical enhancement due to slow blood flow simulates thrombus. We performed cine MR imaging with persaturation tagging, which clearly showed differentiation between thrombus and paradoxical enhancement. We concluded that cine MR imaging with tagging method was useful to evaluate the slow flow and thrombus in the false lumen. (author)

  17. Age- and gender-specific differences in left and right ventricular cardiac function and mass determined by cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Sandstede, J.; Lipke, C.; Beer, M.; Hofmann, S.; Pabst, T.; Kenn, W.; Hahn, D.; Neubauer, S.

    2000-01-01

    We examined possible age- and gender-specific differences in the function and mass of left (LV) and right (RV) ventricles in 36 healthy volunteers using cine gradient-recalled echo magnetic resonance imaging. Subjects were divided into four groups (nine men and nine women in each): men aged under 45 years (32 ± 7), women aged under 45 (27 ± 6), men aged over 45 (59 ± 8), and women aged over 45 (57 ± 9). Functional analysis of cardiac volume and mass and of LV wall motion was performed by manual segmentation of the endocardial and epicardial borders of the end-diastolic and end-systolic frame; both absolute and normalized (per square meter body surface area) values were evaluated. With age there was a significant decrease in both absolute and normalized LV and RV chamber volumes (EDV, ESV), while LV and RV masses remained unchanged. Gender-specific differences were found in cardiac mass and volume (for men and women, respectively: LV mass, 155 ± 18 and 110 ± 16 g; LV EDV, 118 ± 27 and 96 ± 21 ml; LV ESV, 40 ± 13 and 29 ± 9 ml; RV mass, 52 ± 10 and 39 ± 5 g; RV EDV, 131 ± 28 and 100 ± 23 ml; RV ESV, 53 ± 17 and 33 ± 15 ml). Normalization to body surface area eliminated differences in LV volumes but not those in LV mass, RV mass, or RV function. Functional parameters such as cardiac output and LV ejection fraction showed nonsignificant or only slight differences and were thus largely independent of age and gender. Intra- and interobserver variability ranged between 1.4 % and 5.9 % for all parameters. Cine magnetic resonance imaging thus shows age- and gender-specific differences in cardiac function, and therefore the evaluation of cardiac function in patients should consider age- and gender-matched normative values. (orig.)

  18. Highly-Accelerated Real-Time Cardiac Cine MRI Using k-t SPARSE-SENSE

    Science.gov (United States)

    Feng, Li; Srichai, Monvadi B.; Lim, Ruth P.; Harrison, Alexis; King, Wilson; Adluru, Ganesh; Dibella, Edward VR.; Sodickson, Daniel K.; Otazo, Ricardo; Kim, Daniel

    2012-01-01

    For patients with impaired breath-hold capacity and/or arrhythmias, real-time cine MRI may be more clinically useful than breath-hold cine MRI. However, commercially available real-time cine MRI methods using parallel imaging typically yield relatively poor spatio-temporal resolution due to their low image acquisition speed. We sought to achieve relatively high spatial resolution (~2.5mm × 2.5mm) and temporal resolution (~40ms), to produce high-quality real-time cine MR images that could be applied clinically for wall motion assessment and measurement of left ventricular (LV) function. In this work, we present an 8-fold accelerated real-time cardiac cine MRI pulse sequence using a combination of compressed sensing and parallel imaging (k-t SPARSE-SENSE). Compared with reference, breath-hold cine MRI, our 8-fold accelerated real-time cine MRI produced significantly worse qualitative grades (1–5 scale), but its image quality and temporal fidelity scores were above 3.0 (adequate) and artifacts and noise scores were below 3.0 (moderate), suggesting that acceptable diagnostic image quality can be achieved. Additionally, both 8-fold accelerated real-time cine and breath-hold cine MRI yielded comparable LV function measurements, with coefficient of variation cine MRI with k-t SPARSE-SENSE is a promising modality for rapid imaging of myocardial function. PMID:22887290

  19. Highly accelerated real-time cardiac cine MRI using k-t SPARSE-SENSE.

    Science.gov (United States)

    Feng, Li; Srichai, Monvadi B; Lim, Ruth P; Harrison, Alexis; King, Wilson; Adluru, Ganesh; Dibella, Edward V R; Sodickson, Daniel K; Otazo, Ricardo; Kim, Daniel

    2013-07-01

    For patients with impaired breath-hold capacity and/or arrhythmias, real-time cine MRI may be more clinically useful than breath-hold cine MRI. However, commercially available real-time cine MRI methods using parallel imaging typically yield relatively poor spatio-temporal resolution due to their low image acquisition speed. We sought to achieve relatively high spatial resolution (∼2.5 × 2.5 mm(2)) and temporal resolution (∼40 ms), to produce high-quality real-time cine MR images that could be applied clinically for wall motion assessment and measurement of left ventricular function. In this work, we present an eightfold accelerated real-time cardiac cine MRI pulse sequence using a combination of compressed sensing and parallel imaging (k-t SPARSE-SENSE). Compared with reference, breath-hold cine MRI, our eightfold accelerated real-time cine MRI produced significantly worse qualitative grades (1-5 scale), but its image quality and temporal fidelity scores were above 3.0 (adequate) and artifacts and noise scores were below 3.0 (moderate), suggesting that acceptable diagnostic image quality can be achieved. Additionally, both eightfold accelerated real-time cine and breath-hold cine MRI yielded comparable left ventricular function measurements, with coefficient of variation cine MRI with k-t SPARSE-SENSE is a promising modality for rapid imaging of myocardial function. Copyright © 2012 Wiley Periodicals, Inc.

  20. Implementation of DMLC quality control using EPID (Portal Dosimetry); Implementacao de um controle de qualidade de DMLC utilizando um EPID (Portal Dosimetry)

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Fabio R.; Furnari, Laura, E-mail: mattos.fr@gmail.com [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina; Universidade de Sao Paulo (INRAD/HC/FMUSP), Sao Paulo, SP (Brazil). Instituto de Radiologia. Setor de Radioterapia

    2017-11-01

    A Quality Assurance (QA) to ensure the expected performance of a Multileaf Collimator System (MLC) is essential to deliver dose in a safety and appropriate way. The time required for equipment control and dosimetry may be reduced when the Electronic Portal Image Device (EPID) is used. The aim of this work was to check the resolution limits of the detection system for IMRT mode, and to propose a set of tests that can provide positioning analysis of a multileaf system. A Varian iX Clinac equipped with an 80 leaf Millenium MLC, and an amorphous silicon based EPID (aS1000) was used. The EPID proved itself effective for detecting errors up to 0.5 mm. The proposed tests provided relevant results of leaf position, and revealed that the MLC system is within acceptable limits found in literature. (author)

  1. SU-E-J-69: Iterative Deconvolution of the Initial Photon Fluence for EPID Dosimetry: A Monte Carlo Based Study

    Energy Technology Data Exchange (ETDEWEB)

    Czarnecki, D; Voigts-Rhetz, P von; Shishechian, D Uchimura [Technische Hochschule Mittelhessen - University of Applied Sciences, Giessen (Germany); Zink, K [Technische Hochschule Mittelhessen - University of Applied Sciences, Giessen (Germany); Germany and Department of Radiotherapy and Radiooncology, University Medical Center Giessen-Marburg, Marburg (Germany)

    2015-06-15

    Purpose: Developing a fast and accurate calculation model to reconstruct the applied photon fluence from an external photon radiation therapy treatment based on an image recorded by an electronic portal image device (EPID). Methods: To reconstruct the initial photon fluence the 2D EPID image was corrected for scatter from the patient/phantom and EPID to generate the transmitted primary photon fluence. This was done by an iterative deconvolution using precalculated point spread functions (PSF). The transmitted primary photon fluence was then backprojected through the patient/phantom geometry considering linear attenuation to receive the initial photon fluence applied for the treatment.The calculation model was verified using Monte Carlo simulations performed with the EGSnrc code system. EPID images were produced by calculating the dose deposition in the EPID from a 6 MV photon beam irradiating a water phantom with air and bone inhomogeneities and the ICRP anthropomorphic voxel phantom. Results: The initial photon fluence was reconstructed using a single PSF and position dependent PSFs which depend on the radiological thickness of the irradiated object. Appling position dependent point spread functions the mean uncertainty of the reconstructed initial photon fluence could be reduced from 1.13 % to 0.13 %. Conclusion: This study presents a calculation model for fluence reconstruction from EPID images. The{sup Result} show a clear advantage when position dependent PSF are used for the iterative reconstruction. The basic work of a reconstruction method was established and further evaluations must be made in an experimental study.

  2. SU-F-T-476: Performance of the AS1200 EPID for Periodic Photon Quality Assurance

    Energy Technology Data Exchange (ETDEWEB)

    DeMarco, J; Fraass, B; Yang, W; McKenzie Boehnke, E [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Moran, J [University Michigan Medical Center, Ann Arbor, MI (United States); Barnes, M [Calvary Mater Hospital Newcastle, Warratah, NSW (Australia); Greer, P [Calvary Mater Newcastle, Newcastle (Australia); Kim, G [University of California, San Diego, La Jolla, CA (United States)

    2016-06-15

    Purpose: To assess the dosimetric performance of a new amorphous silicon flat-panel electronic portal imaging device (EPID) suitable for high-intensity, flattening-filter-free delivery mode. Methods: An EPID-based QA suite was created with automation to periodically monitor photon central-axis output and two-dimensional beam profile constancy as a function of gantry angle and dose-rate. A Varian TrueBeamTM linear accelerator installed with Developer Mode was used to customize and deliver XML script routines for the QA suite using the dosimetry mode image acquisition for an aS1200 EPID. Automatic post-processing software was developed to analyze the resulting DICOM images. Results: The EPID was used to monitor photon beam output constancy (central-axis), flatness, and symmetry over a period of 10 months for four photon beam energies (6x, 15x, 6xFFF, and 10xFFF). EPID results were consistent to those measured with a standard daily QA check device. At the four cardinal gantry angles, the standard deviation of the EPID central-axis output was <0.5%. Likewise, EPID measurements were independent for the wide range of dose rates (including up to 2400 mu/min for 10xFFF) studied with a standard deviation of <0.8% relative to the nominal dose rate for each energy. Also, profile constancy and field size measurements showed good agreement with the reference acquisition of 0° gantry angle and nominal dose rate. XML script files were also tested for MU linearity and picket-fence delivery. Using Developer Mode, the test suite was delivered in <60 minutes for all 4 photon energies with 4 dose rates per energy and 5 picket-fence acquisitions. Conclusion: Dosimetry image acquisition using a new EPID was found to be accurate for standard and high-intensity photon beams over a broad range of dose rates over 10 months. Developer Mode provided an efficient platform to customize the EPID acquisitions by using custom script files which significantly reduced the time. This work was funded

  3. Música y Cine

    OpenAIRE

    Olarte Martínez, Matilde María

    2008-01-01

    Materiales de clase: Introducción a la Historia de la Música en el Cine; partituras de cine mudo; música clásica y cine; textos sobre música incidental. Se Analiza la música utilizada en cinematografía, y el estudio de sus funciones aplicada a la imagen. Audiciones de música incidental y música preexistente de los principales compositores. la música utilizada en cinematografía, y el estudio de sus funciones aplicada a la imagen. Audiciones de música incidental y música preexistente de los ...

  4. Assessment of cerebellar pulsation in dogs with and without Chiari-like malformation and syringomyelia using cardiac-gated cine magnetic resonance imaging.

    Science.gov (United States)

    Driver, C J; Watts, V; Bunck, A C; Van Ham, L M; Volk, H A

    2013-10-01

    Canine Chiari-like malformation (CM) is characterised by herniation of part of the cerebellum through the foramen magnum. In humans with Chiari type I malformation (CM-I), abnormal pulsation of the cerebellum during the cardiac cycle has been documented and is pivotal to theories for the pathogenesis of syringomyelia (SM). In this retrospective study, cardiac-gated cine balanced fast field echo (bFEE) magnetic resonance imaging (MRI) was used to assess pulsation of the brain in dogs and to objectively measure the degree of cerebellar pulsation with the neck in a flexed position. Overall, 17 Cavalier King Charles Spaniels (CKCS) with CM, including eight with SM and nine without SM, were compared with six small breed control dogs. Linear regions of interest were generated for the length of cerebellar herniation from each phase of the cardiac cycle and the degree of cerebellar pulsation was subsequently calculated. Age, bodyweight and angle of neck flexion were also compared. CKCS with CM and SM had significantly greater pulsation of the cerebellum than control dogs (P=0.003) and CKCS with CM only (P=0.031). There was no significant difference in age, bodyweight and angle of neck flexion between the three groups. Cardiac-gated cine bFEE MRI permitted the dynamic visualisation of cerebellar pulsation in dogs. These findings support the current theories regarding the pathogenesis of SM secondary to CM and further highlight the similarities between canine CM and human CM-I. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Dual breath-hold magnetic resonance cine evaluation of global and regional cardiac function

    International Nuclear Information System (INIS)

    Wintersperger, Bernd J.; Dietrich, Olaf; Huber, Armin; Reiser, Maximilian F.; Schoenberg, Stefan O.; Sincleair, Spencer; Runge, Val M.

    2007-01-01

    The purpose of our study was to evaluate the accuracy of a multislice cine magnetic resonance imaging (MRI) technique with parallel imaging in regard to global and regional left ventricular function. Forty-two individuals underwent cine MRI on a 1.5-tesla scanner. Cine MRI used a steady-state free precession technique and was performed as a single-slice technique (nonTSENSE cine) and an accelerated multislice technique (TSENSE cine) with five slices per breath-hold. End diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF) were evaluated for all data sets and in regard to regional wall motion and regional wall motion analysis, and quantitative regional wall thickness and systolic thickening were also assessed. EDV, ESV, and EF based on TSENSE cine showed excellent correlation to the nonTSENSE cine approach (all r 2 =0.99, P<0.001). While EDV evaluations showed a small underestimation for TSENSE cine, ESV and EF showed accurate results compared with nonTSENSE cine. Both readers showed good agreement (κ=0.72) in regional wall motion assessment comparing both techniques. Data acquisition for the multislice approach was significantly shorter (∝75%) that in single-slice cine. We conclude that accurate evaluation of regional wall motion and left ventricular EF is possible using accelerated multislice cine MR with high spatial and temporal resolution. (orig.)

  6. Contrast-enhanced specific absorption rate-efficient 3D cardiac cine with respiratory-triggered radiofrequency gating.

    Science.gov (United States)

    Henningsson, Markus; Chan, Raymond H; Goddu, Beth; Goepfert, Lois A; Razavi, Reza; Botnar, Rene M; Schaeffter, Tobias; Nezafat, Reza

    2013-04-01

    To investigate the use of radiofrequency (RF) gating in conjunction with a paramagnetic contrast agent to reduce the specific absorption rate (SAR) and increase the blood-myocardium contrast in balanced steady-state free precession (bSSFP) 3D cardiac cine. RF gating was implemented by synchronizing the RF-excitation with an external respiratory sensor (bellows), which could additionally be used for respiratory gating. For reference, respiratory-gated 3D cine images were acquired without RF gating. Free-breathing 3D cine images were acquired in eight healthy subjects before and after contrast injection (Gd-BOPTA) and compared to breath-hold 2D cine. RF-gated 3D cine reduced the SAR by nearly 40% without introducing significant artifacts while providing left ventricle (LV) measurements similar to those obtained with 2D cine. The contrast-to-noise ratio (CNR) was significantly higher for 3D cine compared to 2D cine, both before and after contrast injection; however, no statistically significant CNR increase was observed for the postcontrast 3D cine compared to the precontrast acquisitions. Respiratory-triggered RF gating significantly reduces SAR in 3D cine acquisitions, which may enable a more widespread clinical use of 3D cine. Furthermore, CNR of 3D bSSFP cine is higher than of 2D and administration of Gd-BOPTA does not improve the CNR of 3D cine. Copyright © 2012 Wiley Periodicals, Inc.

  7. Rapid MR assessment of left ventricular systolic function after acute myocardial infarction using single breath-hold cine imaging with the temporal parallel acquisition technique (TPAT) and 4D guide-point modelling analysis of left ventricular function

    International Nuclear Information System (INIS)

    Eberle, Holger C.; Jensen, Christoph J.; Sabin, Georg V.; Naber, Christoph K.; Bruder, Oliver; Nassenstein, Kai; Schlosser, Thomas

    2010-01-01

    We compared four-dimensional guide-point modelling left ventricular function analysis (4DVF) results of cine images in four short-axis and two long-axis slices acquired in a single breath-hold, obtained with the temporal parallel acquisition technique (TPAT), with standard left ventricular function (LVF) analysis results determined by the summation of discs method, in patients who had recently suffered myocardial infarction. Despite wall motion abnormalities, 4DVF yields results for left ventricular ejection fractions and end-diastolic and end-systolic volumes that are in excellent agreement with standard LVF analysis results in these patients. A shortened cardiac magnetic resonance (CMR) protocol using single breath-hold cine image acquisition could facilitate the assessment of left ventricular function soon after myocardial infarction in critically ill patients who are unable to comply with the multiple breath-holds required for standard LVF analysis. (orig.)

  8. Comparison of a multi-breath-hold and a single breath-hold cine imaging approach for 4D guide-point modeling of the left ventricle

    International Nuclear Information System (INIS)

    Heilmaier, C.; Schlosser, T.; Nassenstein, K.; Bruder, O.

    2010-01-01

    Purpose: Guide-point modeling (GPM) enables reliable and time-efficient assessment of left ventricular (LV) volumes when using sequences that allow acquisition of short- and long-axis scans within a single breath-hold. Slice misalignment may influence GPM analysis of standard multi-breath-hold images due to image acquisition in different breath-holds. Thus, our study aimed to assess if such an approach allows for reliable volumetric calculations in the clinical routine. Materials and Methods: 52 patients were examined on a 1.5 T scanner with multi-breath-hold acquisitions on the standard short- and long-axis using an SSFP (TR 3 ms, TE 1.5 ms, FA 60 ) sequence and a TPAT accelerated SSFP (TR 4.6 msec, TE 1.1msec, FA 60 , acceleration factor 3) sequence that covered the LV in 3 short- and 2 long-axis slices within a single breath-hold. For both datasets GPM was used to assess LV volumes. In addition, LV parameters were calculated by applying the summation of slices (SoS) approach (standard of reference) with the short-axis views of the multi-breath-hold dataset. Results: The post-processing times were shorter with both GPM approaches (both, p 0.97). Conclusion: Cine short- and long-axis images that had been acquired in different breath-holds can be reliably evaluated by the GPM approach. (orig.)

  9. Phase-contrast cine MR imaging of normal aqueductal CSF flow. Effect of aging and relation to CSF void on modulus MR

    International Nuclear Information System (INIS)

    Barkhof, F.; Kouwenhoven, M.; Scheltens, P.; Sprenger, M.; Algra, P.; Valk, J.

    1994-01-01

    Cine phase-contrast MR imaging was used to study pulsatile CSF flow in the aqueduct in 11 young controls (mean age 30 years) and 9 old controls (mean age 69 years). A high-resolution gradient echo technique and an oblique imaging plane, perpendicular to the aqueduct, was used to avoid volume averaging. Phantom studies confirmed that the technique was accurate. Aqueductal velocity and flux in old controls was higher than in young controls, but the differences were not significant. For all controls together, the averaged peak velocity was 4.2 ± 1.5 cm/s in rostral and -7.8 ± 4.9 cm/s in caudal direction; for the flux it was 0.16 ± 0.10 cm 3 /s in rostral and -0.29 ± 0.19 cm 3 /s in caudal direction. Phase-contrast measurements were significantly related to flow-void on modulus MR images, but not with ventricular size or cortical atrophy. The present technique avoids underestimation of aqueductal flow, and therefore reveals higher aqueductal velocity and flux values than previous studies. Factors other than age or atrophy seem to determine aqueductal CSF flow. (orig.)

  10. On the use of EPID-based implanted marker tracking for 4D radiotherapy

    International Nuclear Information System (INIS)

    Keall, P.J.; Todor, A.D.; Vedam, S.S.; Bartee, C.L.; Siebers, J.V.; Kini, V.R.; Mohan, R.

    2004-01-01

    Four-dimensional (4D) radiotherapy delivery to dynamically moving tumors requires a real-time signal of the tumor position as a function of time so that the radiation beam can continuously track the tumor during the respiration cycle. The aim of this study was to develop and evaluate an electronic portal imaging device (EPID)-based marker-tracking system that can be used for real-time tumor targeting, or 4D radiotherapy. Three gold cylinders, 3 mm in length and 1 mm in diameter, were implanted in a dynamic lung phantom. The phantom range of motion was 4 cm with a 3-s 'breathing' period. EPID image acquisition parameters were modified, allowing image acquisition in 0.1 s. Images of the stationary and moving phantom were acquired. Software was developed to segment automatically the marker positions from the EPID images. Images acquired in 0.1 s displayed higher noise and a lower signal-noise ratio than those obtained using regular (>1 s) acquisition settings. However, the markers were still clearly visible on the 0.1-s images. The motion of the phantom blurred the images of the markers and further reduced the signal-noise ratio, though they could still be successfully segmented from the images in 10-30 ms of computation time. The positions of gold markers placed in the lung phantom were detected successfully, even for phantom velocities substantially higher than those observed for typical lung tumors. This study shows that using EPID-based marker tracking for 4D radiotherapy is feasible, however, changes in linear accelerator technology and EPID-based image acquisition as well as patient studies are required before this method can be implemented clinically

  11. Evaluation of highly accelerated real-time cardiac cine MRI in tachycardia.

    Science.gov (United States)

    Bassett, Elwin C; Kholmovski, Eugene G; Wilson, Brent D; DiBella, Edward V R; Dosdall, Derek J; Ranjan, Ravi; McGann, Christopher J; Kim, Daniel

    2014-02-01

    Electrocardiogram (ECG)-gated breath-hold cine MRI is considered to be the gold standard test for the assessment of cardiac function. However, it may fail in patients with arrhythmia, impaired breath-hold capacity and poor ECG gating. Although ungated real-time cine MRI may mitigate these problems, commercially available real-time cine MRI pulse sequences using parallel imaging typically yield relatively poor spatiotemporal resolution because of their low image acquisition efficiency. As an extension of our previous work, the purpose of this study was to evaluate the diagnostic quality and accuracy of eight-fold-accelerated real-time cine MRI with compressed sensing (CS) for the quantification of cardiac function in tachycardia, where it is challenging for real-time cine MRI to provide sufficient spatiotemporal resolution. We evaluated the performances of eight-fold-accelerated cine MRI with CS, three-fold-accelerated real-time cine MRI with temporal generalized autocalibrating partially parallel acquisitions (TGRAPPA) and ECG-gated breath-hold cine MRI in 21 large animals with tachycardia (mean heart rate, 104 beats per minute) at 3T. For each cine MRI method, two expert readers evaluated the diagnostic quality in four categories (image quality, temporal fidelity of wall motion, artifacts and apparent noise) using a Likert scale (1-5, worst to best). One reader evaluated the left ventricular functional parameters. The diagnostic quality scores were significantly different between the three cine pulse sequences, except for the artifact level between CS and TGRAPPA real-time cine MRI. Both ECG-gated breath-hold cine MRI and eight-fold accelerated real-time cine MRI yielded all four scores of ≥ 3.0 (acceptable), whereas three-fold-accelerated real-time cine MRI yielded all scores below 3.0, except for artifact (3.0). The left ventricular ejection fraction (LVEF) measurements agreed better between ECG-gated cine MRI and eight-fold-accelerated real-time cine MRI

  12. Anatomy-based, patient-specific VMAT QA using EPID or MLC log files.

    Science.gov (United States)

    Defoor, Dewayne L; Vazquez-Quino, Luis A; Mavroidis, Panayiotis; Papanikolaou, Nikos; Stathakis, Sotirios

    2015-05-08

    In this project, we investigated the use of an electronic portal imaging device (EPID), together with the treatment planning system (TPS) and MLC log files, to determine the delivered doses to the patient and evaluate the agreement between the treatment plan and the delivered dose distribution. The QA analysis results are presented for 15 VMAT patients using the EPID measurements, the ScandiDos Delta4 dosimeter, and the beam fluence calculated from the multileaf collimator (MLC) log file. EPID fluence images were acquired in continuous acquisition mode for each of the patients and they were processed through an in-house MATLAB program to create an opening density matrix (ODM), which was used as the input fluence for the dose calculation in the TPS (Pinnacle3). The EPID used in this study was the aSi1000 Varian on a Novalis TX linac equipped with high-definition MLC. The actual MLC positions and gantry angles were retrieved from the MLC log files and the data were used to calculate the delivered dose distributions in Pinnacle. The resulting dose distributions were then compared against the corresponding planned dose distributions using the 3D gamma index with 3 mm/3% passing criteria. The ScandiDos Delta4 phantom was also used to measure a 2D dose distribution for all the 15 patients and a 2D gamma was calculated for each patient using the Delta4 software. The average 3D gamma using the EPID images was 96.1% ± 2.2%. The average 3D gamma using the log files was 98.7% ± 0.5%. The average 2D gamma from the Delta4 was 98.1% ± 2.1%. Our results indicate that the use of the EPID, combined with MLC log files and a TPS, is a viable method for QA of VMAT plans.

  13. Cine CT in the evaluation of coronary bypass graft patency

    International Nuclear Information System (INIS)

    Stanford, W.; Rooholamini, M.; Rumberger, J.; Marcus, M.; Hiratzka, L.

    1986-01-01

    Cine CT produces axial images over an 8-cm section of the aorta in 50 msec. This characteristic makes the technique useful for evaluating coronary bypass graft (CBG) patency. With the use of 40 ml of 67% iothalamate sodium injected via an antecubital vein, 28 patients with 68 CBGs underwent cine CT. Ten patients with 21 CBGs also underwent cardiac catheterization. In the latter group the overall accuracy of cine CT compared to cardiac catheterization was 95.2% (20/21). The sensitivity was 94.1% (16/17), and the specificity was 100% (4/4). This figure compares favorably with the 92% sensitivity achieved with conventional CT

  14. TH-AB-202-01: Daily Lung Tumor Motion Characterization On EPIDs Using a Markerless Tiling Model

    International Nuclear Information System (INIS)

    Rozario, T; Chiu, T; Lu, W; Chen, M; Yan, Y; Bereg, S; Mao, W

    2016-01-01

    Purpose: Tracking lung tumor motion in real time allows for target dose escalation while simultaneously reducing dose to sensitive structures, thus increasing local control without increasing toxicity. We present a novel intra-fractional markerless lung tumor tracking algorithm using MV treatment beam images acquired during treatment delivery. Strong signals superimposed on the tumor significantly reduced the soft tissue resolution; while different imaging modalities involved introduce global imaging discrepancies. This reduced the comparison accuracies. A simple yet elegant Tiling algorithm is reported to overcome the aforementioned issues. Methods: MV treatment beam images were acquired continuously in beam’s eye view (BEV) by an electronic portal imaging device (EPID) during treatment and analyzed to obtain tumor positions on every frame. Every frame of the MV image was simulated by a composite of two components with separate digitally reconstructed radiographs (DRRs): all non-moving structures and the tumor. This Titling algorithm divides the global composite DRR and the corresponding MV projection into sub-images called tiles. Rigid registration is performed independently on tile-pairs in order to improve local soft tissue resolution. This enables the composite DRR to be transformed accurately to match the MV projection and attain a high correlation value through a pixel-based linear transformation. The highest cumulative correlation for all tile-pairs achieved over a user-defined search range indicates the 2-D coordinates of the tumor location on the MV projection. Results: This algorithm was successfully applied to cine-mode BEV images acquired during two SBRT plans delivered five times with different motion patterns to each of two phantoms. Approximately 15000 beam’s eye view images were analyzed and tumor locations were successfully identified on every projection with a maximum/average error of 1.8 mm / 1.0 mm. Conclusion: Despite the presence of

  15. On the evaluation of patient specific IMRT QA using EPID, dynalog files and patient anatomy

    Directory of Open Access Journals (Sweden)

    Dewayne Lee Defoor

    2014-03-01

    Full Text Available Purpose: This research, investigates the viability of using the Electronic portal imaging device (EPID coupled with the treatment planning system (TPS, to calculate the doses delivered and verify agreement with the treatment plan. The results of QA analysis using the EPID, Delta4 and fluence calculations using the multi-leaf collimator (MLC dynalog files on 10 IMRT patients are presented in this study.Methods: EPID Fluence Images in integrated mode and Dynalog files for each field were acquired for 10 IMRT (6MV patients and processed through an in house MatLab program to create an opening density matrix (ODM which was used as the input fluence for dose calculation with the TPS (Pinnacle3, Philips. The EPID used in this study was the aSi1000 Varian on a Novalis TX linac equipped with high definition MLC. The resulting dose distributions were then exported to VeriSoft (PTW where a 3D gamma was calculated using 3 mm-3% criteria. The Scandidos Delta4 phantom was also used to measure a 2D dose distribution for all 10 patients and a 2D gamma was calculated for each patient using the Delta4 software.Results: The average 3D gamma for all 10 patients using the EPID images was 98.2% ± 2.6%. The average 3D gamma using the dynalog files was 94.6% ± 4.9%. The average 2D gamma from the Delta4 was 98.1% ± 2.5%. The minimum 3D gamma for the EPID and dynalog reconstructed dose distributions was found on the same patient which had a very large PTV, requiring the jaws to open to the maximum field size. Conclusion: Use of the EPID, combined with a TPS is a viable method for QA of IMRT plans. A larger ODM size can be implemented to accommodate larger field sizes. An adaptation of this process to Volumetric Arc Therapy (VMAT is currently under way.-----------------------------Cite this article as: Defoor D, Mavroidis P, Quino L, Gutierrez A, Papanikolaou N, Stathakis S. On the evaluation of patient specific IMRT QA using EPID, dynalog files and patient anatomy

  16. SU-F-T-259: GPR Tables for the Estimation of Mid-Plane Dose Using EPID

    Energy Technology Data Exchange (ETDEWEB)

    Annamalai, Gopiraj [Government Arignar Anna Memorial Cancer Hospital & Research Institute, Kanchipuram, TAMILNADU (India); Watanabe, Yoichi [University of Minnesota, Minneapolis, MN (United States)

    2016-06-15

    Purpose: To develop a simple method for estimating the mid-plane dose (MPD) of a patient using Electronic Portal imaging Device (EPID). Methods: A Varian TrueBeam with aSi100 EPID was used in this study. The EPID images were acquired for a 30 cm × 30 cm homogeneous slab phantom and a 30 cm diameter 20 cm thick cylindrical phantom in the continuous dosimetry mode. The acquired EPID images in XIM format were imported into in-house MATLAB program for the data analysis. First, the dosimetric characteristics of EPID were studied for dose-response linearity, dose-rate dependence, and field size dependence. Next, the average pixels values of the EPID images were correlated with the MPD measured by an ionisation chamber for various thicknesses of the slab phantom (8 cm – 30 cm) and for various square field sizes (3×3 cm{sup 2} – 25×25 cm{sup 2} at the isocenter). Look-up tables called as GPR tables were then generated for both SSD and SAD setup by taking the ratio of MPD measured by the ionisation chamber and the corresponding EPID pixel values. The accuracy of the GPR tables was evaluated by varying the field size, phantom thickness, and wedge angles with the slab and cylindrical phantoms. Results: The dose response of EPID was linear from 20 MU to 300 MU. The EPID response for different dose rates from 40 MU/min to 600 MU/min was within ±1%. The difference in the doses from the GPR tables and the doses measured by the ionization chambers were within 2% for slab phantoms, and 3% for the cylindrical phantom for various field sizes, phantom thickness, and wedge angles. Conclusion: GPR tables are a ready reckoner for in-vivo dosimetry and it can be used to quickly estimate the MPD value from the EPID images with an accuracy of ±3% for common clinical treatment. project work funded by Union for International cancer control(UICC) under ICRETT fellowship.

  17. SU-F-T-259: GPR Tables for the Estimation of Mid-Plane Dose Using EPID

    International Nuclear Information System (INIS)

    Annamalai, Gopiraj; Watanabe, Yoichi

    2016-01-01

    Purpose: To develop a simple method for estimating the mid-plane dose (MPD) of a patient using Electronic Portal imaging Device (EPID). Methods: A Varian TrueBeam with aSi100 EPID was used in this study. The EPID images were acquired for a 30 cm × 30 cm homogeneous slab phantom and a 30 cm diameter 20 cm thick cylindrical phantom in the continuous dosimetry mode. The acquired EPID images in XIM format were imported into in-house MATLAB program for the data analysis. First, the dosimetric characteristics of EPID were studied for dose-response linearity, dose-rate dependence, and field size dependence. Next, the average pixels values of the EPID images were correlated with the MPD measured by an ionisation chamber for various thicknesses of the slab phantom (8 cm – 30 cm) and for various square field sizes (3×3 cm 2 – 25×25 cm 2 at the isocenter). Look-up tables called as GPR tables were then generated for both SSD and SAD setup by taking the ratio of MPD measured by the ionisation chamber and the corresponding EPID pixel values. The accuracy of the GPR tables was evaluated by varying the field size, phantom thickness, and wedge angles with the slab and cylindrical phantoms. Results: The dose response of EPID was linear from 20 MU to 300 MU. The EPID response for different dose rates from 40 MU/min to 600 MU/min was within ±1%. The difference in the doses from the GPR tables and the doses measured by the ionization chambers were within 2% for slab phantoms, and 3% for the cylindrical phantom for various field sizes, phantom thickness, and wedge angles. Conclusion: GPR tables are a ready reckoner for in-vivo dosimetry and it can be used to quickly estimate the MPD value from the EPID images with an accuracy of ±3% for common clinical treatment. project work funded by Union for International cancer control(UICC) under ICRETT fellowship

  18. Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE

    International Nuclear Information System (INIS)

    Gao, Hao; Luo, Xiaoyu; Allan, Andrew; McComb, Christie; Berry, Colin

    2014-01-01

    Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (− 0.18 ± 0.04 versus − 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p < 0.01). In the patient study, the peak strain patterns predicted by cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice. (paper)

  19. Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE.

    Science.gov (United States)

    Gao, Hao; Allan, Andrew; McComb, Christie; Luo, Xiaoyu; Berry, Colin

    2014-07-07

    Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (- 0.18 ± 0.04 versus - 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice.

  20. Automated Motion Estimation for 2D Cine DENSE MRI

    Science.gov (United States)

    Gilliam, Andrew D.; Epstein, Frederick H.

    2013-01-01

    Cine displacement encoding with stimulated echoes (DENSE) is a magnetic resonance (MR) method that directly encodes tissue displacement into MR phase images. This technique has successfully interrogated many forms of tissue motion, but is most commonly used to evaluate cardiac mechanics. Currently, motion analysis from cine DENSE images requires manually delineated anatomical structures. An automated analysis would improve measurement throughput, simplify data interpretation, and potentially access important physiological information during the MR exam. In this article, we present the first fully automated solution for the estimation of tissue motion and strain from 2D cine DENSE data. Results using both simulated and human cardiac cine DENSE data indicate good agreement between the automated algorithm and the standard semi-manual analysis method. PMID:22575669

  1. Evaluation of flow volume and flow patterns in the patent false lumen of chronic aortic dissections using velocity-encoded cine magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Toshihisa; Watanabe, Shigeru; Sakurada, Hideki; Ono, Katsuhiro; Urano, Miharu; Hijikata, Yasuyoshi; Saito, Isao; Masuda, Yoshiaki [Chiba Univ. (Japan). School of Medicine

    2000-10-01

    In 21 patients with chronic aortic dissections and proven patent false lumens, the flow volume and flow patterns in the patent false lumens was evaluated using velocity-encoded cine magnetic resonance imaging (VENC-MRI) and the relationship between the flow characteristics and aortic enlargement was retrospectively examined. Flow patterns in the false lumen were divided into 3 groups: pattern A with primarily antegrade flow (n=6), pattern R with primarily retrograde flow (n=3), and pattern B with bidirectional flow (n=12). In group A, the rate of flow volume in the false lumen compared to the total flow volume in true and false lumens (%TFV) and the average rate of enlargement of the maximum diameter of the dissected aorta per year ({delta}D) were significantly greater than in groups R and B (%TFV: 74.1{+-}0.07 vs 15.2{+-}0.03 vs 11.8{+-}0.04, p<0.01; {delta}D: 3.62{+-}0.82 vs 0 vs 0.58{+-}0.15 mm/year, p<0.05, respectively). There was a significant correlation between %TFV and {delta}D (r=0.79, p<0.0001). Evaluation of flow volume and flow patterns in the patent false lumen using VENC-MRI may be useful for predicting enlargement of the dissected aorta. (author)

  2. Evaluation of flow volume and flow patterns in the patent false lumen of chronic aortic dissections using velocity-encoded cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Inoue, Toshihisa; Watanabe, Shigeru; Sakurada, Hideki; Ono, Katsuhiro; Urano, Miharu; Hijikata, Yasuyoshi; Saito, Isao; Masuda, Yoshiaki

    2000-01-01

    In 21 patients with chronic aortic dissections and proven patent false lumens, the flow volume and flow patterns in the patent false lumens was evaluated using velocity-encoded cine magnetic resonance imaging (VENC-MRI) and the relationship between the flow characteristics and aortic enlargement was retrospectively examined. Flow patterns in the false lumen were divided into 3 groups: pattern A with primarily antegrade flow (n=6), pattern R with primarily retrograde flow (n=3), and pattern B with bidirectional flow (n=12). In group A, the rate of flow volume in the false lumen compared to the total flow volume in true and false lumens (%TFV) and the average rate of enlargement of the maximum diameter of the dissected aorta per year (ΔD) were significantly greater than in groups R and B (%TFV: 74.1±0.07 vs 15.2±0.03 vs 11.8±0.04, p<0.01; ΔD: 3.62±0.82 vs 0 vs 0.58±0.15 mm/year, p<0.05, respectively). There was a significant correlation between %TFV and ΔD (r=0.79, p<0.0001). Evaluation of flow volume and flow patterns in the patent false lumen using VENC-MRI may be useful for predicting enlargement of the dissected aorta. (author)

  3. Source position verification and dosimetry in HDR brachytherapy using an EPID

    International Nuclear Information System (INIS)

    Smith, R. L.; Taylor, M. L.; McDermott, L. N.; Franich, R. D.; Haworth, A.; Millar, J. L.

    2013-01-01

    Purpose: Accurate treatment delivery in high dose rate (HDR) brachytherapy requires correct source dwell positions and dwell times to be administered relative to each other and to the surrounding anatomy. Treatment delivery inaccuracies predominantly occur for two reasons: (i) anatomical movement or (ii) as a result of human errors that are usually related to incorrect implementation of the planned treatment. Electronic portal imaging devices (EPIDs) were originally developed for patient position verification in external beam radiotherapy and their application has been extended to provide dosimetric information. The authors have characterized the response of an EPID for use with an 192 Ir brachytherapy source to demonstrate its use as a verification device, providing both source position and dosimetric information.Methods: Characterization of the EPID response using an 192 Ir brachytherapy source included investigations of reproducibility, linearity with dose rate, photon energy dependence, and charge build-up effects associated with exposure time and image acquisition time. Source position resolution in three dimensions was determined. To illustrate treatment verification, a simple treatment plan was delivered to a phantom and the measured EPID dose distribution compared with the planned dose.Results: The mean absolute source position error in the plane parallel to the EPID, for dwells measured at 50, 100, and 150 mm source to detector distances (SDD), was determined to be 0.26 mm. The resolution of the z coordinate (perpendicular distance from detector plane) is SDD dependent with 95% confidence intervals of ±0.1, ±0.5, and ±2.0 mm at SDDs of 50, 100, and 150 mm, respectively. The response of the EPID is highly linear to dose rate. The EPID exhibits an over-response to low energy incident photons and this nonlinearity is incorporated into the dose calibration procedure. A distance (spectral) dependent dose rate calibration procedure has been developed. The

  4. Memoria y Cine

    OpenAIRE

    Getino, Octavio

    2006-01-01

    El cine argentino conserva como puntos básicos de referencia las obras de portavoces de la memoria y de la historia popular. Obras no sólo de fecha reciente, sino también aquellas que nacen con la propia industria cinematográfica. Este artículo, cuyas reflexiones –según coincidimos con su autor– conservan vigencia, apareció por primera vez en México, en 1984, en Notas sobre cine argentino y latinoamericano, una publicación que reunió diversos aportes sobre la cinematografía nacional y lati...

  5. Cine-CT: A new technique in X-ray computed tomography

    International Nuclear Information System (INIS)

    Jaschke, W.; Georgi, M.; Lipton, M.J.; Gould, R.G.

    1988-01-01

    The 'Cine-CT' belongs to a new generation of CT devices permitting not only diagnostics on a morphological basis but also function studies. By means of Cine-CT's electron beam technique, image frequencies of up to 17 images per second and exposure times of 50 msec are possible. (orig.) [de

  6. Quantitative T2 mapping after reperfusion therapy in patients with acute myocardial infarction: A comparison with late gadolinium enhancement and cine MR imaging.

    Science.gov (United States)

    Park, Chul Hwan; Choi, Eui-Young; Yoon, Young Won; Kwon, Hyuck Moon; Hong, Bum Kee; Lee, Byoung Kwon; Min, Pil-Ki; Greiser, Andreas; Paek, Mun Young; Hwang, Sung Ho; Kim, Tae Hoon

    2015-12-01

    This study evaluates myocardial edema by quantitative T2 mapping in patients with acute myocardial infarction (AMI) and compares the lateral extent of myocardial edema with those of infarcted and dysfunctional myocardium. Cardiac magnetic resonance images (MRIs) of 31 patients (M:F=29:2, mean age: 52.5±10.8years) with AMI were reviewed. On cine-MRI, all short axis images of the left ventricle (LV) were divided into 60 sectors. The regional wall motion of each sector was calculated as follows: systolic wall thickening (SWT, %)=[(LV wall thicknessES-LV wall thicknessED)/LV wall thicknessED]*100. Dysfunctional myocardium was defined as sectors with decreased SWT lower than 40%. On LGE-images, myocardial infarction was defined as an area of hyper-enhancement more than 5 SDs from the remote myocardium. On T2 map, myocardial edema was defined as an area in which T2 values were at least 2 SDs higher than those from remote myocardium. The lateral extents of infarcted myocardium, myocardial edema, and dysfunctional myocardium were calculated as the percentage of central angles ((central angle of the involved myocardium/360)*100 (%)) and then compared. The lateral extent of myocardial edema was slightly larger than that of infarcted myocardium (37.4±13.3% vs. 35±12.9%, pinfarcted myocardium or myocardial edema (pmyocardial edema beyond the infarcted myocardium might be narrow, but the dysfunctional myocardium could be significantly larger than myocardial edema, suggesting stunned myocardium without edema. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. El cine posmoderno

    Directory of Open Access Journals (Sweden)

    Edel Cadena Vargas

    2015-05-01

    Full Text Available En el presente trabajo se trata de dar respuesta a las siguientes preguntas: ¿cuál es el origen del cine posmoderno?, ¿cuáles son los factores que permiten su creación?, ¿a qué sentimiento responde?

  8. SU-E-T-05: A 2D EPID Transit Dosimetry Model Based On An Empirical Quadratic Formalism

    International Nuclear Information System (INIS)

    Tan, Y; Metwaly, M; Glegg, M; Baggarley, S; Elliott, A

    2014-01-01

    Purpose: To describe a 2D electronic portal imaging device (EPID) transit dosimetry model, based on an empirical quadratic formalism, that can predict either EPID or in-phantom dose distribution for comparisons with EPID captured image or treatment planning system (TPS) dose respectively. Methods: A quadratic equation can be used to relate the reduction in intensity of an exit beam to the equivalent path length of the attenuator. The calibration involved deriving coefficients from a set of dose planes measured for homogeneous phantoms with known thicknesses under reference conditions. In this study, calibration dose planes were measured with EPID and ionisation chamber (IC) in water for the same reference beam (6MV, 100mu, 20×20cm 2 ) and set of thicknesses (0–30cm). Since the same calibration conditions were used, the EPID and IC measurements can be related through the quadratic equation. Consequently, EPID transit dose can be predicted from TPS exported dose planes and in-phantom dose can be predicted using EPID distribution captured during treatment as an input. The model was tested with 4 open fields, 6 wedge fields, and 7 IMRT fields on homogeneous and heterogeneous phantoms. Comparisons were done using 2D absolute gamma (3%/3mm) and results were validated against measurements with a commercial 2D array device. Results: The gamma pass rates for comparisons between EPID measured and predicted ranged from 93.6% to 100.0% for all fields and phantoms tested. Results from this study agreed with 2D array measurements to within 3.1%. Meanwhile, comparisons in-phantom between TPS computed and predicted ranged from 91.6% to 100.0%. Validation with 2D array device was not possible for inphantom comparisons. Conclusion: A 2D EPID transit dosimetry model for treatment verification was described and proven to be accurate. The model has the advantage of being generic and allows comparisons at the EPID plane as well as multiple planes in-phantom

  9. Improved attenuation correction for respiratory gated PET/CT with extended-duration cine CT: a simulation study

    Science.gov (United States)

    Zhang, Ruoqiao; Alessio, Adam M.; Pierce, Larry A.; Byrd, Darrin W.; Lee, Tzu-Cheng; De Man, Bruno; Kinahan, Paul E.

    2017-03-01

    Due to the wide variability of intra-patient respiratory motion patterns, traditional short-duration cine CT used in respiratory gated PET/CT may be insufficient to match the PET scan data, resulting in suboptimal attenuation correction that eventually compromises the PET quantitative accuracy. Thus, extending the duration of cine CT can be beneficial to address this data mismatch issue. In this work, we propose to use a long-duration cine CT for respiratory gated PET/CT, whose cine acquisition time is ten times longer than a traditional short-duration cine CT. We compare the proposed long-duration cine CT with the traditional short-duration cine CT through numerous phantom simulations with 11 respiratory traces measured during patient PET/CT scans. Experimental results show that, the long-duration cine CT reduces the motion mismatch between PET and CT by 41% and improves the overall reconstruction accuracy by 42% on average, as compared to the traditional short-duration cine CT. The long-duration cine CT also reduces artifacts in PET images caused by misalignment and mismatch between adjacent slices in phase-gated CT images. The improvement in motion matching between PET and CT by extending the cine duration depends on the patient, with potentially greater benefits for patients with irregular breathing patterns or larger diaphragm movements.

  10. Cine MRI of swallowing in patients with advanced oral or oropharyngeal carcinoma: a feasibility study.

    Science.gov (United States)

    Kreeft, Anne Marijn; Rasch, Coen R N; Muller, Sara H; Pameijer, Frank A; Hallo, Eeke; Balm, Alfons J M

    2012-06-01

    Treatment of oral and oropharyngeal cancer may cause dysphagia. Purpose is to examine whether cine magnetic resonance imaging (MRI) yields additional information compared to standard examination in the evaluation of posttreatment dysphagia and mobility of oral and oropharyngeal structures. Thirty-four cine MRIs were made in 23 patients with advanced oral and oropharyngeal cancer, consisting of an MR image every 800 ms during swallowing which is compared to videofluoroscopy and quality of life questionnaires. A scoring system was applied to assess mobility on cine MR and videofluoroscopy leading to a score ranging from 9 to 17. Cine MRI of the swallowing in a midsagittal plane visualized the tumor (if located in the same plane), important anatomic structures and surgical reconstructions. Posttreatment mobility on cine MRI and videofluoroscopy was significantly diminished compared to pretreatment, mean pretreatment cine MRI score was 10.8 and posttreatment 12.4 (p = 0.017). Impaired mobility on cine MRI was significantly correlated to more swallowing problems (Spearman's correlation coefficient 0.73, p = 0.04), on videofluoroscopy not. Cine MRI is a promising new technique as an adjunct to standard examinations for evaluation of swallowing in patients with oral and oropharyngeal cancer. Cine MRI directly visualizes the dynamics of swallowing and allows evaluation of pre- and posttreatment differences. Abnormal findings are significantly correlated with subjective swallowing complaints of patients.

  11. Calibration of an EPID to perform pretreatment portal dosimetry in IMRT non-transmission: the algorithm iGRiMLO; Calibracion de un EPID para la realizacion de dosimetria portal pretratamiento de no transmision en IMRT: el algoritmo iGRiMLO

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, V.; Dolores, V. de los; Martinez, J.; Pastor, V.; Gimeno, J.; Guardino, C.; Crispin, V.

    2011-07-01

    This paper explains the process of calibration of a portal imaging device (EPID) of an amorphous silicon flat panel. This algorithm was programmed iGRiMLO based on an experimental method, where not required convolution operations.

  12. Virtual EPID standard phantom audit (VESPA) for remote IMRT and VMAT credentialing

    Science.gov (United States)

    Miri, Narges; Lehmann, Joerg; Legge, Kimberley; Vial, Philip; Greer, Peter B.

    2017-06-01

    A virtual EPID standard phantom audit (VESPA) has been implemented for remote auditing in support of facility credentialing for clinical trials using IMRT and VMAT. VESPA is based on published methods and a clinically established IMRT QA procedure, here extended to multi-vendor equipment. Facilities are provided with comprehensive instructions and CT datasets to create treatment plans. They deliver the treatment directly to their EPID without any phantom or couch in the beam. In addition, they deliver a set of simple calibration fields per instructions. Collected EPID images are uploaded electronically. In the analysis, the dose is projected back into a virtual cylindrical phantom. 3D gamma analysis is performed. 2D dose planes and linear dose profiles are provided and can be considered when needed for clarification. In addition, using a virtual flat-phantom, 2D field-by-field or arc-by-arc gamma analyses are performed. Pilot facilities covering a range of planning and delivery systems have performed data acquisition and upload successfully. Advantages of VESPA are (1) fast turnaround mainly driven by the facility’s capability of providing the requested EPID images, (2) the possibility for facilities performing the audit in parallel, as there is no need to wait for a phantom, (3) simple and efficient credentialing for international facilities, (4) a large set of data points, and (5) a reduced impact on resources and environment as there is no need to transport heavy phantoms or audit staff. Limitations of the current implementation of VESPA for trials credentialing are that it does not provide absolute dosimetry, therefore a Level I audit is still required, and that it relies on correctly delivered open calibration fields, which are used for system calibration. The implemented EPID based IMRT and VMAT audit system promises to dramatically improve credentialing efficiency for clinical trials and wider applications.

  13. Free-breathing steady-state free precession cine cardiac magnetic resonance with respiratory navigator gating.

    Science.gov (United States)

    Moghari, Mehdi H; Komarlu, Rukmini; Annese, David; Geva, Tal; Powell, Andrew J

    2015-04-01

    To develop and validate a respiratory motion compensation method for free-breathing cardiac cine imaging. A free-breathing navigator-gated cine steady-state free precession acquisition (Cine-Nav) was developed which preserves the equilibrium state of the net magnetization vector, maintains the high spatial and temporal resolutions of standard breath-hold (BH) acquisition, and images entire cardiac cycle. Cine image data is accepted only from cardiac cycles occurring entirely during end-expiration. Prospective validation was performed in 10 patients by obtaining in each three complete ventricular image stacks with different respiratory motion compensation approaches: (1) BH, (2) free-breathing with 3 signal averages (3AVG), and (3) free-breathing with Cine-Nav. The subjective image quality score (1 = worst, 4 = best) for Cine-Nav (3.8 ± 0.4) was significantly better than for 3AVG (2.2 ± 0.5, P = 0.002), and similar to BH (4.0 ± 0.0, P = 0.13). The blood-to-myocardium contrast ratio for Cine-Nav (6.3 ± 1.5) was similar to BH (5.9 ± 1.6, P = 0.52) and to 3AVG (5.6 ± 2.5, P = 0.43). There were no significant differences between Cine-Nav and BH for the ventricular volumes and mass. In contrast, there were significant differences between 3AVG and BH in all of these measurements but right ventricular mass. Free-breathing cine imaging with Cine-Nav yielded comparable image quality and ventricular measurements to BH, and was superior to 3AVG. © 2014 Wiley Periodicals, Inc.

  14. Cine computed tomography for diagnosis of superior vena cava obstruction following the mustard operation

    International Nuclear Information System (INIS)

    Matherne, G.P.; Atkins, D.L.; Frey, E.E.; Smith, W.L.

    1987-01-01

    Superior vena caval obstruction is a well described complication following Mustard's repair for transposition of the great arteries. We report a case of a 6-year-old child with superior vena cava obstruction correctly diagnosed by Cine-CT. The advantages of imaging with Cine-CT for this complication are discussed. (orig.)

  15. Simultaneous static and cine nonenhanced MR angiography using radial sampling and highly constrained back projection reconstruction.

    Science.gov (United States)

    Koktzoglou, Ioannis; Mistretta, Charles A; Giri, Shivraman; Dunkle, Eugene E; Amin, Parag; Edelman, Robert R

    2014-10-01

    To describe a pulse sequence for simultaneous static and cine nonenhanced magnetic resonance angiography (NEMRA) of the peripheral arteries. The peripheral arteries of 10 volunteers and 6 patients with peripheral arterial disease (PAD) were imaged with the proposed cine NEMRA sequence on a 1.5 Tesla (T) system. The impact of multi-shot imaging and highly constrained back projection (HYPR) reconstruction was examined. The propagation rate of signal along the length of the arterial tree in the cine nonenhanced MR angiograms was quantified. The cine NEMRA sequence simultaneously provided a static MR angiogram showing vascular anatomy as well as a cine display of arterial pulse wave propagation along the entire length of the peripheral arteries. Multi-shot cine NEMRA improved temporal resolution and reduced image artifacts. HYPR reconstruction improved image quality when temporal reconstruction footprints shorter than 100 ms were used (P cine NEMRA was slower in patients with PAD than in volunteers. Simultaneous static and cine NEMRA of the peripheral arteries is feasible. Multi-shot acquisition and HYPR reconstruction can be used to improve arterial conspicuity and temporal resolution. Copyright © 2013 Wiley Periodicals, Inc.

  16. Cine y literatura

    Directory of Open Access Journals (Sweden)

    Jorge Enrique Adoum

    2015-01-01

    Full Text Available El lanzamiento de la undécima edición de la novela de Jorge Enrique Adoum "Entre Marx y una mujer desnuda" y el comienzo simultáneo de la filmación de la película basada en esa obra, ha puesto nuevamente de relieve, el recurrente tema de la literatura llevada al cine. En ese sentido, en agosto, se llevó a cabo una mesa redonda en la que participaron como exponentes Camilo Luzuriaga (director del filme, Omar Ospina (crítico cinematográfico y jorge Enrique Adoum. En el siguiente artículo -basado en su exposición en la mesa redonda-, el reconocido escritor analiza cómo debe ser para él la vinculación entre literatura y cine.

  17. A comprehensive study of the mechanical performance of gantry, EPID and the MLC assembly in Elekta linacs during gantry rotation

    DEFF Research Database (Denmark)

    Rowshanfarzad, P; Lynggaard Riis, Hans; Zimmermann, S J

    2015-01-01

    bank assembly owing to linac rotation were separately investigated by acquisition of 37 EPID images of a simple phantom with 5 ball bearings at various gantry angles. A fast and robust software package was developed for automated analysis of the image data. Nine Elekta AB (Stockholm, Sweden) linacs...... collimator leaf bank assemblies was around 1 mm. A meaningful correlation was found between the age of the linacs and their mechanical performance. Conclusions and Advances in knowledge: The method and software developed in this study provide a simple tool for effective investigation of the behaviour...... of different models and number of years in service were investigated. RESULTS: The average EPID sag was within 2 mm for all tested linacs. Some machines showed >1-mm gantry sag. Changes in the SDD values were within 1.3 cm. EPID skewness and tilt values were

  18. Cine e identidades virtuales

    Directory of Open Access Journals (Sweden)

    Labrador Ben, Julia María

    2006-12-01

    Full Text Available The subject is the ability the cinema has performed - since its very begining - as a creation instrument of national and transnational identities. In the first place, it covers Spanish cinema since 1938 and right after the end of the Spanish Civil War, II World War Italian-German cinema, Eisenstein’s, Leni Riefenstahl’s, Griffth’s and Ford’s cinema, the role American war and science fiction productions played, as well as the comedies dealing with the divided Berlin subject. The role of computers and video-games and the new cinema positionings that forecast the end of what is real, is studied through films such as Tron, The Lawnmower Man, Johnny Mnemonic, Ghost in the shell, Simone o Matrix.Se estudia la capacidad del cine desde sus orígenes como instrumento de generación de identidades nacionales y transnacionales. Se realiza, en primer lugar, un recorrido por el cine español desde 1938 y tras el final de la guerra civil, el cine italo-alemán de la II Guerra Mundial, el cine de Eisenstein, Leni Riefenstahl, Griffth y Ford, y el papel que jugaron las producciones norteamericanas bélicas y de ciencia ficción, así como las comedias sobre el Berlín dividido. El papel de los ordenadores y los videojuegos, y los nuevos planteamientos cinematográficos que pronostican el final de lo real se estudia a través de películas como Tron, El cortador de césped, Johnny Mnemonic, Ghost in the shell, Simone o Matrix.

  19. Cine MRI: a new approach to the diagnosis of scapholunate dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Langner, I.; Eisenschenk, A. [University Medicine Greifswald, Division of Hand Surgery and Functional Microsurgery, Department of Trauma and Reconstructive Surgery, Greifswald (Germany); Fischer, S.; Langner, S. [University Medicine Greifswald, Institute for Diagnostic Radiology and Neuroradiology, Greifswald (Germany)

    2015-08-15

    To evaluate the feasibility of cine MRI for the detection of scapholunate dissociation (SLD) and to compare the sensitivity and specificity of cine MRI with those of cineradiography and arthroscopy. To evaluate feasibility, healthy subjects underwent cine MRI of the wrist. To evaluate sensitivity and specificity, patients with clinically suspected scapholunate ligament (SLL) injury after trauma to the wrist were prospectively included and underwent radiographic examination, cineradiography, and cine MRI. In 25 out of 38 patients, subsequent arthroscopy was performed. Results of cineradiography and cine MRI correlated with those of arthroscopy. Cine MRI was of diagnostic quality in all healthy subjects and patients with good interrater agreement. There was excellent correlation between cineradiography and cine MRI. Scapholunate distance differed significantly between healthy subjects and patients with scapholunate dissociation (p < 0.001), but not between imaging modalities in the patient group. Cine MRI had 85 % sensitivity and 90 % specificity for the detection of SLD. Cine MRI of the wrist is a fast and reliable technique for the detection of SLD with diagnostic accuracy comparable to cineradiography. It can be easily implemented as a routine clinical MRI examination, facilitating diagnostic workup of patients with suspected SLD while avoiding radiation exposure. (orig.)

  20. The Cine Club de Lima

    Directory of Open Access Journals (Sweden)

    Ricardo Bedoya

    2009-10-01

    Full Text Available Cine Club de Lima was the most important cinematography culture spreading institution of the fifties. It was also the precursor of other movie clubs of following decades, which would bring together important Peruvian intellectuals from every art form, who would together promote cultural entertainment. This piece describes ”Cine Club Lima” origins and dissolution, while taking into account its programs.

  1. Preliminary studies for implementation of a MCL quality control using EPID (Portal Dosimetry); Estudos preliminares para implementacao de um controle de qualidade de MLC com o uso do EPID (Portal Dosimetry)

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Fabio R.; Furnari, Laura [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina

    2016-07-01

    A Quality Control (CQ) to ensure the expected performance of a Multileaf Collimator System (MLC) is essential for delivering dose in a safety and appropriate way. The time required for equipment control and dosimetry may be lowered when the Electronic Portal Image Device (EPID) is used. The aim of this paper was to check the resolution limits of the detection system for IMRT mode, and to do the analysis of three tests of MLC performance: Picket Fence, Slinding GAP, MLC versus Gantry. A Varian iX Clinac equipped with an 80 leaf Millennium MLC and with amorphous silicon based EPID (aS1000) was use. The EPID proved Effective, where errors up to 0,5 mm can be detected. Information about interleaf transmissions, dose profile and gravity influence in the leaf banks also were included. (author)

  2. Robustness and precision of an automatic marker detection algorithm for online prostate daily targeting using a standard V-EPID.

    Science.gov (United States)

    Aubin, S; Beaulieu, L; Pouliot, S; Pouliot, J; Roy, R; Girouard, L M; Martel-Brisson, N; Vigneault, E; Laverdière, J

    2003-07-01

    An algorithm for the daily localization of the prostate using implanted markers and a standard video-based electronic portal imaging device (V-EPID) has been tested. Prior to planning, three gold markers were implanted in the prostate of seven patients. The clinical images were acquired with a BeamViewPlus 2.1 V-EPID for each field during the normal course radiotherapy treatment and are used off-line to determine the ability of the automatic marker detection algorithm to adequately and consistently detect the markers. Clinical images were obtained with various dose levels from ranging 2.5 to 75 MU. The algorithm is based on marker attenuation characterization in the portal image and spatial distribution. A total of 1182 clinical images were taken. The results show an average efficiency of 93% for the markers detected individually and 85% for the group of markers. This algorithm accomplishes the detection and validation in 0.20-0.40 s. When the center of mass of the group of implanted markers is used, then all displacements can be corrected to within 1.0 mm in 84% of the cases and within 1.5 mm in 97% of cases. The standard video-based EPID tested provides excellent marker detection capability even with low dose levels. The V-EPID can be used successfully with radiopaque markers and the automatic detection algorithm to track and correct the daily setup deviations due to organ motions.

  3. Cine MRI of patients with cervical myelopathy

    International Nuclear Information System (INIS)

    Ukita, Yasutaka

    1993-01-01

    Forty-six patients with cervical myelopathy were examined before and after surgery by cine magnetic resonance imaging (MRI). According to the occurrence site and degree of flow void, cerebrospinal fluid (CSF) flow void was classified into five: anterior type (flow void mainly in the anterior part of subarachnoid space), posterior type (mainly in the posteiror part), anteroposterior type (in the anterior and posterior parts), incomplete block type (flow void limited to the upper and lower parts of the block), and complete block type (no flow void). None of the 46 patients had normal CSF flow void on cine MRI before surgery. CSF flow void was seen in systolic phase on ECG (from 150 to 300 msec from R's wave) in all patients after spinal cord decompression. Postoperative CBF flow void types correlated well with surgical method, disease, and postoperative vertebral alignment. Postoperative outcome was the most excellent in the group of posterior type and the poorest in the group of anteroposterior type, showing a significant difference between the groups. Cine MRI is a useful noninvasive, dynamic method for assessing postoperative decompression effect. (N.K.)

  4. MO-AB-BRA-03: Development of Novel Real Time in Vivo EPID Treatment Verification for Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, G; Podesta, M [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Reniers, B [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Research Group NuTeC, CMK, Hasselt University, Agoralaan Gebouw H, Diepenbeek B-3590 (Belgium); Verhaegen, F [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Medical Physics Unit, Department of Oncology, McGill University, Montreal, Quebec H3G 1A4 (Canada)

    2016-06-15

    Purpose: High Dose Rate (HDR) brachytherapy treatments are employed worldwide to treat a wide variety of cancers. However, in vivo dose verification remains a challenge with no commercial dosimetry system available to verify the treatment dose delivered to the patient. We propose a novel dosimetry system that couples an independent Monte Carlo (MC) simulation platform and an amorphous silicon Electronic Portal Imaging Device (EPID) to provide real time treatment verification. Methods: MC calculations predict the EPID response to the photon fluence emitted by the HDR source by simulating the patient, the source dwell positions and times, and treatment complexities such as tissue compositions/densities and different applicators. Simulated results are then compared against EPID measurements acquired with ∼0.14s time resolution which allows dose measurements for each dwell position. The EPID has been calibrated using an Ir-192 HDR source and experiments were performed using different phantoms, including tissue equivalent materials (PMMA, lung and bone). A source positioning accuracy of 0.2 mm, without including the afterloader uncertainty, was ensured using a robotic arm moving the source. Results: An EPID can acquire 3D Cartesian source positions and its response varies significantly due to differences in the material composition/density of the irradiated object, allowing detection of changes in patient geometry. The panel time resolution allows dose rate and dwell time measurements. Moreover, predicted EPID images obtained from clinical treatment plans provide anatomical information that can be related to the patient anatomy, mostly bone and air cavities, localizing the source inside of the patient using its anatomy as reference. Conclusion: Results obtained show the feasibility of the proposed dose verification system that is capable to verify all the brachytherapy treatment steps in real time providing data about treatment delivery quality and also applicator

  5. Development and implementation of EPID-based quality assurance tests for the small animal radiation research platform (SARRP).

    Science.gov (United States)

    Anvari, Akbar; Poirier, Yannick; Sawant, Amit

    2018-04-28

    Although small animal image-guided radiotherapy (SA-IGRT) systems are used increasingly in preclinical research, tools for performing routine quality assurance (QA) have not been optimized and are not readily available. Robust, efficient, and reliable QA tools are needed to ensure the accuracy and reproducibility of SA-IGRT systems. Several investigators have reported custom-made phantoms and protocols for SA-IGRT systems QA. These are typically time and resource intensive and are therefore not well suited to the preclinical radiotherapy environment, in which physics support is limited and routine QA is performed by technical staff. We investigated the use of the in-built electronic portal imaging device (EPID) to develop and validate routine QA tests and procedures. In this work, we focus on the XSTRAHL Small Animal Radiation Research Platform (SARRP) EPID. However, the methodology and tests developed here are applicable to any SA-IGRT system that incorporates an EPID. We performed a comprehensive characterization of the dosimetric properties of the camera-based EPID at kilovoltage energies over an 11-month period, including detector warm-up time, radiation dose history effect, stability and short- and long-term reproducibility, gantry angle dependency, output factor, and linearity of the EPID response. We developed a test to measure the constancy of beam quality in terms of half-value layer and tube peak potential using the EPID. We verified the SARRP daily output and beam profile constancy using the imager. We investigated the use of the imager to monitor beam targeting accuracy at various gantry and couch angles. The EPID response was stable and reproducible, exhibiting maximum variations of ≤0.3% and ≤1.9% for short and long terms, respectively. The detector showed no dependence on response at different gantry angles, with a maximum variation of ≤0.5%. We found close agreement in output factor measurement between the portal imager and reference

  6. Implementation of EPID transit dosimetry based on a through-air dosimetry algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Sean L.; Sheu, Ren-Dih; Polvorosa, Cynthia S.; Wuu, Cheng-Shie [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States) and Department of Medical Physics, Memorial Sloan Kettering Cancer Cente, New York, New York 10065 (United States); Department of Radiation Oncology, Mount Sinai Medical Center, New York, New York 10029 (United States); Department of Radiation Oncology, Columbia University, New York, New York 10032 (United States)

    2012-01-15

    Purpose: A method to perform transit dosimetry with an electronic portal imaging device (EPID) by extending the commercial implementation of a published through-air portal dose image (PDI) prediction algorithm Van Esch et al.[Radiother. Oncol. 71, 223-234 (2004)] is proposed and validated. A detailed characterization of the attenuation, scattering, and EPID response behind objects in the beam path is used to convert through-air PDIs into transit PDIs. Methods: The EPID detector response beyond a range of water equivalent thicknesses (0-35 cm) and field sizes (3x3 to 22.2x29.6 cm{sup 2}) was analyzed. A constant air gap between the phantom exit surface and the EPID was utilized. A model was constructed that accounts for the beam's attenuation along the central axis, the presence of phantom scattered radiation, the detector's energy dependent response, and the difference in EPID off-axis pixel response relative to the central pixel. The efficacy of the algorithm was verified by comparing predicted and measured PDIs for IMRT fields delivered through phantoms of increasing complexity. Results: The expression that converts a through-air PDI to a transit PDI is dependent on the object's thickness, the irradiated field size, and the EPID pixel position. Monte Carlo derived narrow-beam linear attenuation coefficients are used to model the decrease in primary fluence incident upon the EPID due to the object's presence in the beam. This term is multiplied by a factor that accounts for the broad beam scatter geometry of the linac-phantom-EPID system and the detector's response to the incident beam quality. A 2D Gaussian function that models the nonuniformity of pixel response across the EPID detector plane is developed. For algorithmic verification, 49 IMRT fields were repeatedly delivered to homogeneous slab phantoms in 5 cm increments. Over the entire set of measurements, the average area passing a 3%/3mm gamma criteria slowly decreased from 98% for

  7. Registration of clinical volumes to beams-eye-view images for real-time tracking

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, Jonathan H.; Rottmann, Joerg; Lewis, John H.; Mishra, Pankaj; Berbeco, Ross I., E-mail: rberbeco@lroc.harvard.edu [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Keall, Paul J. [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, Sydney, New South Wales 2006 (Australia)

    2014-12-15

    Purpose: The authors combine the registration of 2D beam’s eye view (BEV) images and 3D planning computed tomography (CT) images, with relative, markerless tumor tracking to provide automatic absolute tracking of physician defined volumes such as the gross tumor volume (GTV). Methods: During treatment of lung SBRT cases, BEV images were continuously acquired with an electronic portal imaging device (EPID) operating in cine mode. For absolute registration of physician-defined volumes, an intensity based 2D/3D registration to the planning CT was performed using the end-of-exhale (EoE) phase of the four dimensional computed tomography (4DCT). The volume was converted from Hounsfield units into electron density by a calibration curve and digitally reconstructed radiographs (DRRs) were generated for each beam geometry. Using normalized cross correlation between the DRR and an EoE BEV image, the best in-plane rigid transformation was found. The transformation was applied to physician-defined contours in the planning CT, mapping them into the EPID image domain. A robust multiregion method of relative markerless lung tumor tracking quantified deviations from the EoE position. Results: The success of 2D/3D registration was demonstrated at the EoE breathing phase. By registering at this phase and then employing a separate technique for relative tracking, the authors are able to successfully track target volumes in the BEV images throughout the entire treatment delivery. Conclusions: Through the combination of EPID/4DCT registration and relative tracking, a necessary step toward the clinical implementation of BEV tracking has been completed. The knowledge of tumor volumes relative to the treatment field is important for future applications like real-time motion management, adaptive radiotherapy, and delivered dose calculations.

  8. Intramyocardial strain estimation from cardiac cine MRI.

    Science.gov (United States)

    Elnakib, Ahmed; Beache, Garth M; Gimel'farb, Georgy; El-Baz, Ayman

    2015-08-01

    Functional strain is one of the important clinical indicators for the quantification of heart performance and the early detection of cardiovascular diseases, and functional strain parameters are used to aid therapeutic decisions and follow-up evaluations after cardiac surgery. A comprehensive framework for deriving functional strain parameters at the endocardium, epicardium, and mid-wall of the left ventricle (LV) from conventional cine MRI data was developed and tested. Cine data were collected using short TR-/TE-balanced steady-state free precession acquisitions on a 1.5T Siemens Espree scanner. The LV wall borders are segmented using a level set-based deformable model guided by a stochastic force derived from a second-order Markov-Gibbs random field model that accounts for the object shape and appearance features. Then, the mid-wall of the segmented LV is determined based on estimating the centerline between the endocardium and epicardium of the LV. Finally, a geometrical Laplace-based method is proposed to track corresponding points on successive myocardial contours throughout the cardiac cycle in order to characterize the strain evolutions. The method was tested using simulated phantom images with predefined point locations of the LV wall throughout the cardiac cycle. The method was tested on 30 in vivo datasets to evaluate the feasibility of the proposed framework to index functional strain parameters. The cine MRI-based model agreed with the ground truth for functional metrics to within 0.30 % for indexing the peak systolic strain change and 0.29 % (per unit time) for indexing systolic and diastolic strain rates. The method was feasible for in vivo extraction of functional strain parameters. Strain indexes of the endocardium, mid-wall, and epicardium can be derived from routine cine images using automated techniques, thereby improving the utility of cine MRI data for characterization of myocardial function. Unlike traditional texture-based tracking, the

  9. CineGlob

    CERN Multimedia

    CineGlob

    2014-01-01

    CERN will be hosting the next CineGlobe International Film Festival from March 18 to 23 at the Globe of Science and Innovation with the theme “Beyond the Frontier”, This 4th edition will see 66 short films “inspired by science” in competition, including fiction films as well as documentaries. From Tuesday the 18th to Friday the 21st, special lunch sessions are organized from 12:30 to 13:30. Food will be available for purchase at the tent “Café Cinéma” next to the Globe. Special evenings While the short film screenings are the heart of the festival, every year CineGlobe also organizes compelling special events every night, from feature films to special musical performances: Tuesday 18th: The Swiss premiere of the acclaimed documentary film Particle Fever. Presented by BBC Storyville with Fabiola Gianotti and director Mark Levinson in attendance; Wednesday 19th: The result of the “Story Matter” Hacka...

  10. A back-projection algorithm in the presence of an extra attenuating medium: towards EPID dosimetry for the MR-Linac

    Science.gov (United States)

    Torres-Xirau, I.; Olaciregui-Ruiz, I.; Rozendaal, R. A.; González, P.; Mijnheer, B. J.; Sonke, J.-J.; van der Heide, U. A.; Mans, A.

    2017-08-01

    In external beam radiotherapy, electronic portal imaging devices (EPIDs) are frequently used for pre-treatment and for in vivo dose verification. Currently, various MR-guided radiotherapy systems are being developed and clinically implemented. Independent dosimetric verification is highly desirable. For this purpose we adapted our EPID-based dose verification system for use with the MR-Linac combination developed by Elekta in cooperation with UMC Utrecht and Philips. In this study we extended our back-projection method to cope with the presence of an extra attenuating medium between the patient and the EPID. Experiments were performed at a conventional linac, using an aluminum mock-up of the MRI scanner housing between the phantom and the EPID. For a 10 cm square field, the attenuation by the mock-up was 72%, while 16% of the remaining EPID signal resulted from scattered radiation. 58 IMRT fields were delivered to a 20 cm slab phantom with and without the mock-up. EPID reconstructed dose distributions were compared to planned dose distributions using the γ -evaluation method (global, 3%, 3 mm). In our adapted back-projection algorithm the averaged {γmean} was 0.27+/- 0.06 , while in the conventional it was 0.28+/- 0.06 . Dose profiles of several square fields reconstructed with our adapted algorithm showed excellent agreement when compared to TPS.

  11. Electronic portal imaging devices

    International Nuclear Information System (INIS)

    Lief, Eugene

    2008-01-01

    The topics discussed include, among others, the following: Role of portal imaging; Port films vs. EPID; Image guidance: Elekta volume view; Delivery verification; Automation tasks of portal imaging; Types of portal imaging (Fluorescent screen, mirror, and CCD camera-based imaging; Liquid ion chamber imaging; Amorpho-silicon portal imagers; Fluoroscopic portal imaging; Kodak CR reader; and Other types of portal imaging devices); QA of EPID; and Portal dosimetry (P.A.)

  12. Cine MRI of swallowing in patients with advanced oral or oropharyngeal carcinoma: a feasibility study

    NARCIS (Netherlands)

    Kreeft, Anne Marijn; Rasch, Coen R. N.; Muller, Sara H.; Pameijer, Frank A.; Hallo, Eeke; Balm, Alfons J. M.

    2012-01-01

    Treatment of oral and oropharyngeal cancer may cause dysphagia. Purpose is to examine whether cine magnetic resonance imaging (MRI) yields additional information compared to standard examination in the evaluation of posttreatment dysphagia and mobility of oral and oropharyngeal structures.

  13. Cine dyscontractility index: A novel marker of mechanical dyssynchrony that predicts response to cardiac resynchronization therapy.

    Science.gov (United States)

    Werys, Konrad; Petryka-Mazurkiewicz, Joanna; Błaszczyk, Łukasz; Miśko, Jolanta; Śpiewak, Mateusz; Małek, Łukasz A; Mazurkiewicz, Łukasz; Miłosz-Wieczorek, Barbara; Marczak, Magdalena; Kubik, Agata; Dąbrowska, Agnieszka; Piątkowska-Janko, Ewa; Sawionek, Błażej; Wijesurendra, Rohan; Piechnik, Stefan K; Bogorodzki, Piotr

    2016-12-01

    To investigate whether magnetic resonance imaging (MRI) cine-derived dyssynchrony indices provide additional information compared to conventional tagged MRI (tMRI) acquisitions in heart failure patients undergoing cardiac resynchronization therapy (CRT). Patients scheduled for CRT (n = 52) underwent preprocedure MRI including cine and tMRI acquisitions. Segmental strain curves were calculated for both cine and tMRI to produce a range of standard indices for direct comparison between modalities. We also proposed and evaluated a novel index of "dyscontractility," which detects the presence of focal areas with paradoxically positive circumferential strain. Across conventional strain indices, there was only moderate-to-poor (R = 0.3-0.6) correlation between modalities; eight cine-derived indices showed statistically significant (P cine images (cine dyscontractility index, "CDI") was the single best predictor of clinical response to CRT (area under the curve AUC = 0.81, P Cine-derived strain indices offer potentially new information compared to tMRI. Specifically, the novel CDI is most strongly linked to response to cardiac resynchronization therapy in a contemporary patient cohort. It utilizes readily available MRI data, is relatively straightforward to process, and compares favorably with any conventional tagging index. J. Magn. Reson. Imaging 2016;44:1483-1492. © 2016 International Society for Magnetic Resonance in Medicine.

  14. Cine-Club

    CERN Multimedia

    Cine-Club

    2011-01-01

    Thursday 10 November 2011 at 20:30 CERN Council Chamber The Counterfeiters / Die Fälscher By: Stefan Ruzowitzky (Germany/Austria, 2007) 98 min With: Karl Markovics, August Diel, Devid Striesow The Counterfeiters is the true story of the largest counterfeiting operation in history, set up by the Nazis in 1936. Master counterfeiter Salomon ‘Sally’ Sorowitsch, a Jew without morals, is arrested and sent to Mauthausen concentration camp, where he weasels through by offering his ‘artistic’ services. After transfer to Sachsenhausen he’s given an official alternative: taking ‘artistic’ charge of a cons teams assigned to produce perfect forgeries of allied banknotes for the Third Reich. Survivor Sally accepts, but conscience matters among the team prove no less dangerous then a sadistic jailer, which only the CO may keep in check. Original version German; English subtitles Entrance: 2 CHF Projection from DVD http://cine...

  15. CINE: Comet INfrared Excitation

    Science.gov (United States)

    de Val-Borro, Miguel; Cordiner, Martin A.; Milam, Stefanie N.; Charnley, Steven B.

    2017-08-01

    CINE calculates infrared pumping efficiencies that can be applied to the most common molecules found in cometary comae such as water, hydrogen cyanide or methanol. One of the main mechanisms for molecular excitation in comets is the fluorescence by the solar radiation followed by radiative decay to the ground vibrational state. This command-line tool calculates the effective pumping rates for rotational levels in the ground vibrational state scaled by the heliocentric distance of the comet. Fluorescence coefficients are useful for modeling rotational emission lines observed in cometary spectra at sub-millimeter wavelengths. Combined with computational methods to solve the radiative transfer equations based, e.g., on the Monte Carlo algorithm, this model can retrieve production rates and rotational temperatures from the observed emission spectrum.

  16. Cine Letras Goytisolo Cartelera

    Directory of Open Access Journals (Sweden)

    Flávio Pimenta de Souza

    2011-10-01

    Full Text Available Resumo: Estudo de investigação sobre a obra literária do escritor Juan Goytisolo em que se analisam comparativamente as técnicas cinematográficas do projeto Dogma 95 e as técnicas literárias do referido autor.Palavras-chave: Literatura espanhola; Juan Goytisolo; cinema.Resumen: Estúdio de investigación sobre la obra literaria del escritor Juan Goytisolo en el que se analizan comparativamente las técnicas cinematográficas del proyecto Dogma 95 y las técnicas literarias de dicho autor.Palabras-clave: Literatura española; Juan Goytisolo; cine.Keywords: Spanish literature; Juan Goytisolo; cinema.

  17. MO-FG-202-01: A Fast Yet Sensitive EPID-Based Real-Time Treatment Verification System

    International Nuclear Information System (INIS)

    Ahmad, M; Nourzadeh, H; Neal, B; Siebers, J; Watkins, W

    2016-01-01

    Purpose: To create a real-time EPID-based treatment verification system which robustly detects treatment delivery and patient attenuation variations. Methods: Treatment plan DICOM files sent to the record-and-verify system are captured and utilized to predict EPID images for each planned control point using a modified GPU-based digitally reconstructed radiograph algorithm which accounts for the patient attenuation, source energy fluence, source size effects, and MLC attenuation. The DICOM and predicted images are utilized by our C++ treatment verification software which compares EPID acquired 1024×768 resolution frames acquired at ∼8.5hz from Varian Truebeam™ system. To maximize detection sensitivity, image comparisons determine (1) if radiation exists outside of the desired treatment field; (2) if radiation is lacking inside the treatment field; (3) if translations, rotations, and magnifications of the image are within tolerance. Acquisition was tested with known test fields and prior patient fields. Error detection was tested in real-time and utilizing images acquired during treatment with another system. Results: The computational time of the prediction algorithms, for a patient plan with 350 control points and 60×60×42cm^3 CT volume, is 2–3minutes on CPU and <27 seconds on GPU for 1024×768 images. The verification software requires a maximum of ∼9ms and ∼19ms for 512×384 and 1024×768 resolution images, respectively, to perform image analysis and dosimetric validations. Typical variations in geometric parameters between reference and the measured images are 0.32°for gantry rotation, 1.006 for scaling factor, and 0.67mm for translation. For excess out-of-field/missing in-field fluence, with masks extending 1mm (at isocenter) from the detected aperture edge, the average total in-field area missing EPID fluence was 1.5mm2 the out-of-field excess EPID fluence was 8mm^2, both below error tolerances. Conclusion: A real-time verification software, with

  18. Value of cine MRI for better visualization of the proximal small bowel in normal individuals

    International Nuclear Information System (INIS)

    Torkzad, Michael R.; Blomqvist, Lennart; Vargas, Roberto; Tanaka, Chikako

    2007-01-01

    While enteroclysis seems to be the most efficacious method in achieving bowel distension, enterographic methods have become widespread due to the unpleasantness of enteroclysis and the radiation involved with positioning the catheter. Cine images in MRI can be done without radiation. Our aim is to see if and how cine MR imaging can improve visualization of bowel loops by capturing them while distended. Ten healthy individuals were asked to drink up to 2,000 ml of an oral solution made locally over a 60-min period. Then they underwent MRI using coronal balanced fast field echo (b-FFE) covering small bowel loops. If the initial exam revealed collapsed bowel loops an additional 50 mg of erythromycine was given intravenously with the subject still in the scanner and then cine imaging was performed. The degree of distension of different segments of the small bowel was measured before and after cine imaging and compared. The distension score was significantly higher after addition of the cine images as well, being only significant for depiction of the duodenum and jejunum. Our preliminary study suggests that cine MRI can give better image depiction of the proximal small bowel in healthy volunteers, perhaps circumventing the need for enteroclysis in some cases. There is a need for validation of these results in patients with small bowel disease. (orig.)

  19. A simple method to back-project isocenter dose of radiotherapy treatments using EPID transit dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, T.B.; Cerbaro, B.Q.; Rosa, L.A.R. da, E-mail: thiago.fisimed@gmail.com, E-mail: tbsilveira@inca.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro - RJ (Brazil)

    2017-07-01

    The aim of this work was to implement a simple algorithm to evaluate isocenter dose in a phantom using the back-projected transmitted dose acquired using an Electronic Portal Imaging Device (EPID) available in a Varian Trilogy accelerator with two nominal 6 and 10 MV photon beams. This algorithm was developed in MATLAB language, to calibrate EPID measured dose in absolute dose, using a deconvolution process, and to incorporate all scattering and attenuation contributions due to photon interactions with phantom. Modeling process was simplified by using empirical curve adjustments to describe the contribution of scattering and attenuation effects. The implemented algorithm and method were validated employing 19 patient treatment plans with 104 clinical irradiation fields projected on the phantom used. Results for EPID absolute dose calibration by deconvolution have showed percent deviations lower than 1%. Final method validation presented average percent deviations between isocenter doses calculated by back-projection and isocenter doses determined with ionization chamber of 1,86% (SD of 1,00%) and -0,94% (SD of 0,61%) for 6 and 10 MV, respectively. Normalized field by field analysis showed deviations smaller than 2% for 89% of all data for 6 MV beams and 94% for 10 MV beams. It was concluded that the proposed algorithm possesses sufficient accuracy to be used for in vivo dosimetry, being sensitive to detect dose delivery errors bigger than 3-4% for conformal and intensity modulated radiation therapy techniques. (author)

  20. Self-gated fat-suppressed cardiac cine MRI.

    Science.gov (United States)

    Ingle, R Reeve; Santos, Juan M; Overall, William R; McConnell, Michael V; Hu, Bob S; Nishimura, Dwight G

    2015-05-01

    To develop a self-gated alternating repetition time balanced steady-state free precession (ATR-SSFP) pulse sequence for fat-suppressed cardiac cine imaging. Cardiac gating is computed retrospectively using acquired magnetic resonance self-gating data, enabling cine imaging without the need for electrocardiogram (ECG) gating. Modification of the slice-select rephasing gradients of an ATR-SSFP sequence enables the acquisition of a one-dimensional self-gating readout during the unused short repetition time (TR). Self-gating readouts are acquired during every TR of segmented, breath-held cardiac scans. A template-matching algorithm is designed to compute cardiac trigger points from the self-gating signals, and these trigger points are used for retrospective cine reconstruction. The proposed approach is compared with ECG-gated ATR-SSFP and balanced steady-state free precession in 10 volunteers and five patients. The difference of ECG and self-gating trigger times has a variability of 13 ± 11 ms (mean ± SD). Qualitative reviewer scoring and ranking indicate no statistically significant differences (P > 0.05) between self-gated and ECG-gated ATR-SSFP images. Quantitative blood-myocardial border sharpness is not significantly different among self-gated ATR-SSFP ( 0.61±0.15 mm -1), ECG-gated ATR-SSFP ( 0.61±0.15 mm -1), or conventional ECG-gated balanced steady-state free precession cine MRI ( 0.59±0.15 mm -1). The proposed self-gated ATR-SSFP sequence enables fat-suppressed cardiac cine imaging at 1.5 T without the need for ECG gating and without decreasing the imaging efficiency of ATR-SSFP. © 2014 Wiley Periodicals, Inc.

  1. Megavoltage conebeam CT cine as final verification of treatment plan in lung stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Kudithipudi, Vijay; Gayou, Olivier; Colonias, Athanasios

    2016-01-01

    To analyse the clinical impact of megavoltage conebeam computed tomography (MV-CBCT) cine on internal target volume (ITV) coverage in lung stereotactic body radiotherapy (SBRT). One hundred and six patients received lung SBRT. All underwent 4D computed tomography simulation followed by treatment via image guided 3D conformal or intensity modulated radiation. Prior to SBRT, all patients underwent MV-CBCT cine, in which raw projections are displayed as beam's-eye-view fluoroscopic series with the planning target volume (PTV) projected onto each image, enabling verification of tumour motion relative to the PTV and assessment of adequacy of treatment margin. Megavoltage conebeam computed tomography cine was completed 1–2 days prior to SBRT. Four patients (3.8%) had insufficient ITV coverage inferiorly at cine review. All four plans were changed by adding 5 mm on the PTV margin inferiorly. The mean change in PTV volumes was 3.9 cubic centimetres (cc) (range 1.85–6.32 cc). Repeat cine was performed after plan modification to ensure adequate PTV coverage in the modified plans. PTV margin was adequate in the majority of patients with this technique. MV-CBCT cine did show insufficient coverage in a small subset of patients. Insufficient PTV margins may be a function of 4D CT simulation inadequacies or deficiencies in visualizing the ITV inferior border in the full-inhale phase. MV-CBCT cine is a valuable tool for final verification of PTV margins.

  2. Comparison of left and right ventricular ejection and filling parameters by fast cine MR imaging in breath-hold technique: clinical study of 42 patients with cardiomyopathy and coronary heart disease; Vergleich links- und rechtsventrikulaerer Auswurf- und Fuellungsparameter des Herzens mittels Cine MRT in Atemanhaltetechnik: klinische Studie an 42 Patienten mit Kardiomyopathie und koronarer Herzerkrankung

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, M.B.; Bachmann, G.F.; Geuer, M.; Puzik, M.; Rau, W.S. [Giessen Univ. (Germany). Diagnostische Radiologie; Ricken, W.W. [Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Abt. Kardiologie

    1999-06-01

    Purpose: Quantification of left and right ventricular filling and ejection of localized and diffuse heart diseases with fast cine MR imaging in breath-hold technique. Methods: 42 patients (14 idiopathic dilated cardiomyopathies (DCM), 13 hypertrophic cardiomyopathies (HCM) and 15 coronary artery diseases (CAD)) and 10 healthy volunteers were examined. Time-volume-curves of three left ventricular and one right ventricular slices were evaluated and peak ejection and filling rates (PER, PFR end-diastolic volume (EDV)/s) time to PER and PFR (TPER, TPFR ms) and time of end-systole (TSYS in % RR-intervall) were calculated. Results: There were significant regional and left-/right-sided differences of the filling and ejection of both ventricles within and between the different groups. In DCM the left ventricular PFR was reduced (DCM 3.1 EDV/s; volunteers 4.9 EDV/s) and Z-SYS prolonged (DCM 50.1%; volunteers 35.4%). In CAD there were localized decreased filling rates in comparison to the normal volunteer group (left ventricle: basal: 2.9 and 6.3 EDV/s, apical: 4.4 and 6.3 EDV/s; right ventricle: 3.6 and 5.7 EDV/s). HCM typically showed an isovolumetric lengthening of the endsystole. Conclusions: Cardiac MR imaging in breath-hold technique is suitable for measuring contraction and relaxation disturbances of localized and diffuse heart diseases by means of ejection and filling volume indices. (orig.) [Deutsch] Ziel: Quantifizierung der links- und rechtsventrikulaeren Fuellung und des Auswurfs bei umschriebenen und diffusen Herzerkrankungen mittels schneller Cine MR Bildgebung in Atemanhaltetechnik. Methoden: Untersucht wurden 42 Patienten (14 dilatative Kardiomyopathien (DCM), 13 hypertrophe obstruktive Kardiomyopathien (HCM) und 15 koronare Herzerkrankungen (KHK)) und 10 Probanden. Von drei linksventrikulaeren und einer rechtsventrikulaeren Einzelschicht wurden Zeit-Volumen-Kurven erstellt, aus denen die maximale Auswurf- und Fuellrate (MAR) (MFR eddiastolisches Volumen (EDV

  3. SU-G-TeP4-07: Automatic EPID-Based 2D Measurement of MLC Leaf Offset as a Quality Control Tool

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, T; Moran, J [The University of Michigan, Ann Arbor, MI (United States); Schultz, B [University of Michigan, Ann Arbor, MI (United States); Kim, G [University of California, San Diego, La Jolla, CA (United States); Barnes, M [Calvary Mater Hospital Newcastle, Warratah, NSW (Australia); Perez, M [North Sydney Cancer Center, Sydney (Australia); Farrey, K [University of Chicago, Chicago, IL (United States); Popple, R [University Alabama Birmingham, Birmingham, AL (United States); Greer, P [Calvary Mater Newcastle, Newcastle (Australia)

    2016-06-15

    Purpose: The MLC dosimetric leaf gap (DLG) and transmission are measured parameters which impact the dosimetric accuracy of IMRT and VMAT plans. This investigation aims to develop an efficient and accurate routine constancy check of the physical DLG in two dimensions. Methods: The manufacturer’s recommended DLG measurement method was modified by using 5 fields instead of 11 and by utilizing the Electronic Portal Imaging Device (EPID). Validations were accomplished using an ion chamber (IC) in solid water and a 2D IC array. EPID data was collected for 6 months on multiple TrueBeam linacs using both Millennium and HD MLCs at 5 different clinics in an international consortium. Matlab code was written to automatically analyze the images and calculate the 2D results. Sensitivity was investigated by introducing deliberate leaf position errors. MLC calibration and initialization history was recorded to allow quantification of their impact. Results were analyzed using statistical process control (SPC). Results: The EPID method took approximately 5 minutes. Due to detector response, the EPID measured DLG and transmission differed from the IC values but were reproducible and consistent with changes measured using the ICs. For the Millennium MLC, the EPID measured DLG and transmission were both consistently lower than IC results. The EPID method was implemented as leaf offset and transmission constancy tests (LOC and TC). Based on 6 months of measurements, the initial leaf-specific action thresholds for changes from baseline were set to 0.1 mm. Upper and lower control limits for variation were developed for each machine. Conclusion: Leaf offset and transmission constancy tests were implemented on Varian HD and Millennium MLCs using an EPID and found to be efficient and accurate. The test is effective for monitoring MLC performance using dynamic delivery and performing process control on the DLG in 2D, thus enhancing dosimetric accuracy. This work was supported by a grant

  4. Left Ventricle: Fully Automated Segmentation Based on Spatiotemporal Continuity and Myocardium Information in Cine Cardiac Magnetic Resonance Imaging (LV-FAST

    Directory of Open Access Journals (Sweden)

    Lijia Wang

    2015-01-01

    Full Text Available CMR quantification of LV chamber volumes typically and manually defines the basal-most LV, which adds processing time and user-dependence. This study developed an LV segmentation method that is fully automated based on the spatiotemporal continuity of the LV (LV-FAST. An iteratively decreasing threshold region growing approach was used first from the midventricle to the apex, until the LV area and shape discontinued, and then from midventricle to the base, until less than 50% of the myocardium circumference was observable. Region growth was constrained by LV spatiotemporal continuity to improve robustness of apical and basal segmentations. The LV-FAST method was compared with manual tracing on cardiac cine MRI data of 45 consecutive patients. Of the 45 patients, LV-FAST and manual selection identified the same apical slices at both ED and ES and the same basal slices at both ED and ES in 38, 38, 38, and 41 cases, respectively, and their measurements agreed within -1.6±8.7 mL, -1.4±7.8 mL, and 1.0±5.8% for EDV, ESV, and EF, respectively. LV-FAST allowed LV volume-time course quantitatively measured within 3 seconds on a standard desktop computer, which is fast and accurate for processing the cine volumetric cardiac MRI data, and enables LV filling course quantification over the cardiac cycle.

  5. Discursos subversivos en el cine no hablado

    Directory of Open Access Journals (Sweden)

    Rodríguez Fernández, M.ª del Carmen

    2012-12-01

    Full Text Available “Subversive discourses in silent films” aims to analyse the gender transgression that emerges in certain movies of the silent period. These being silent films, their meaning can only be understood from the content of the images. Directors of the silent period were aware of the importance of images and of their power to put across their views to spectators. The field of filmmaking was new but it was not ungendered, and women filmmakers knew that their films were the vehicle to make spectators aware of their feminist positions. Le matelas alcoolique, La souriante Mme. Beudet and Dora Films of America Shorts are examples of this privilege since, although they belong to two periods of silent film history and have different aims, the directors and the films selected are good examples to be revisited with a gender perspective.

    “Discursos subversivos en el cine no hablado” se propone analizar las transgresiones de género que aparecen en algunas películas del cine mudo. Por sus características al tratarse de un cine no hablado, lo que sugieren algunas imágenes es fundamental para entender los significados de las películas. Las directoras de aquella época eran conocedoras de la importancia de las imágenes y del poder que les confería la cámara para expresar sus reivindicaciones al público espectador. El campo de la cinematografía era nuevo, pero tenía género y las directoras sabían que sus películas eran el vehículo para dar a conocer su articulación como feministas. Le matelas alcoolique, La souriante Mme. Beudet y Dora Films of America Shorts son ejemplos de este privilegio puesto que, aunque las películas de esta muestra pertenezcan a dos etapas del cine mudo y de que sus propósitos fueran diferentes, las directoras y las películas seleccionadas son ejemplos merecedores de una revisión con perspectiva de género.

  6. MO-D-213-08: Remote Dosimetric Credentialing for Clinical Trials with the Virtual EPID Standard Phantom Audit (VESPA)

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, J [Calvary Mater Newcastle, Newcastle, NSW (Australia); University of Sydney, Sydney, NSW (Australia); Miri, N [University of Newcastle, Newcastle, NSW (Australia); Vial, P [Liverpool Hospital, Liverpool, NSW (Australia); Hatton, J [Trans Tasman Radiation Oncology Group (TROG), Newcastle, NSW (Australia); Zwan, B; Sloan, K [Gosford Hospital, Gosford, NSW (Australia); Craig, A; Beenstock, V [Canterbury Regional Cancer and Haematology Service, Christchurch (New Zealand); Molloy, T [Orange Hospital, Orange, NSW (Australia); Greer, P [Calvary Mater Newcastle, Newcastle, NSW (Australia); University of Newcastle, Newcastle, NSW (Australia)

    2015-06-15

    Purpose: Report on implementation of a Virtual EPID Standard Phantom Audit (VESPA) for IMRT to support credentialing of facilities for clinical trials. Data is acquired by local facility staff and transferred electronically. Analysis is performed centrally. Methods: VESPA is based on published methods and a clinically established IMRT QA procedure, here extended to multi-vendor equipment. Facilities, provided with web-based comprehensive instructions and CT datasets, create IMRT treatment plans. They deliver the treatments directly to their EPID without phantom or couch in the beam. They also deliver a set of simple calibration fields. Collected EPID images are uploaded electronically. In the analysis, the dose is projected back into a virtual phantom and 3D gamma analysis is performed. 2D dose planes and linear dose profiles can be analysed when needed for clarification. Results: Pilot facilities covering a range of planning and delivery systems have performed data acquisition and upload successfully. Analysis showed agreement comparable to local experience with the method. Advantages of VESPA are (1) fast turnaround mainly driven by the facility’s capability to provide the requested EPID images, (2) the possibility for facilities performing the audit in parallel, as there is no need to wait for a phantom, (3) simple and efficient credentialing for international facilities, (4) a large set of data points, and (5) a reduced impact on resources and environment as there is no need to transport heavy phantoms or audit staff. Limitations of the current implementation of VESPA for trials credentialing are that it does not provide absolute dosimetry, therefore a Level 1 audit still required, and that it relies on correctly delivered open calibration fields, which are used for system calibration. Conclusion: The implemented EPID based IMRT audit system promises to dramatically improve credentialing efficiency for clinical trials and wider applications. VESPA for VMAT

  7. SU-F-T-469: A Clinically Observed Discrepancy Between Image-Based and Log- Based MLC Position

    Energy Technology Data Exchange (ETDEWEB)

    Neal, B; Ahmed, M; Siebers, J [University of Virginia Health System, Charlottesville, VA (United States)

    2016-06-15

    Purpose: To present a clinical case which challenges the base assumption of log-file based QA, by showing that the actual position of a MLC leaf can suddenly deviate from its programmed and logged position by >1 mm as observed with real-time imaging. Methods: An EPID-based exit-fluence dosimetry system designed to prevent gross delivery errors was used in cine mode to capture portal images during treatment. Visual monitoring identified an anomalous MLC leaf pair gap not otherwise detected by the automatic position verification. The position of the erred leaf was measured on EPID images and log files were analyzed for the treatment in question, the prior day’s treatment, and for daily MLC test patterns acquired on those treatment days. Additional standard test patterns were used to quantify the leaf position. Results: Whereas the log file reported no difference between planned and recorded positions, image-based measurements showed the leaf to be 1.3±0.1 mm medial from the planned position. This offset was confirmed with the test pattern irradiations. Conclusion: It has been clinically observed that log-file derived leaf positions can differ from their actual positions by >1 mm, and therefore cannot be considered to be the actual leaf positions. This cautions the use of log-based methods for MLC or patient quality assurance without independent confirmation of log integrity. Frequent verification of MLC positions through independent means is a necessary precondition to trusting log file records. Intra-treatment EPID imaging provides a method to capture departures from MLC planned positions. Work was supported in part by Varian Medical Systems.

  8. Comparison of fluoro and cine coronary angiography: balancing acceptable outcomes with a reduction in radiation dose.

    Science.gov (United States)

    Olcay, Ayhan; Guler, Ekrem; Karaca, Ibrahim Oguz; Omaygenc, Mehmet Onur; Kizilirmak, Filiz; Olgun, Erkam; Yenipinar, Esra; Cakmak, Huseyin Altug; Duman, Dursun

    2015-04-01

    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.

  9. Movimientos migratorios y cine

    Directory of Open Access Journals (Sweden)

    Manuel Galiano León

    2009-12-01

    Full Text Available Nuestro artículo se ha centrado en el estudio de las películas de mayor distribución comercial para ver cómo éstas han representado el tema de la migración y qué reflexiones sugieren. En general, creemos que el reconocimiento por parte del cine de este fenómeno es positivo y que indudablemente constituye una fuente esencial para comprender las realidades migratorias distinguiendo discursos diversos y explicitando intenciones y hechos que intentan ocultarse u olvidarse.__________________ABSTRACT:Our article focuses on the study of the most commercial movies to check the way they present the subject of immigration and which kind of reflections they suggest. In general, we believe that the recognition of the migration phenomena in the cinema world is positive and it is actually an esential source to understand the reality of migration, being able to recognize different discourses and showing intentions and facts which are hidden or forgotten.  

  10. Cine-Club

    CERN Document Server

    Cine-Club

    2011-01-01

    Lundi 12 décembre 2011 à 18:30 Salle du Conseil Comme chaque année avant Noël, le CINE-CLUB du CERN est heureux d’inviter petits et grands à une projection gratuite du film : Ponyo sur la falaise (Japon, 2008, Hayao Miyazaki) Le petit Sosuke vit avec sa mère sur une haute falaise surplombant la mer. Un beau jour, il découvre sur la plage caillouteuse Ponyo, une petite fille poisson. Ponyo est si fascinée par Sosuke et le monde terrestre que son désir le plus cher est de devenir un être humain. Mais Fujimoto, son magicien de père, n’est pas du tout d’accord avec cette idée et il la force à regagner les profondeurs de l’océan. Bien décidée à revoir Sosuke, Ponyo s’échappe de sa prison sous-marine, mais ce faisant elle déclenche une immense catastroph...

  11. Cine Club - Special Event

    CERN Multimedia

    Cine Club

    2017-01-01

    Special event on Thursday 4 May 2017 at 18:30 CERN Council Chamber In collaboration with the CERN Running Club and the Women In Technology initiative, the CERN CineClub is happy to announce the screening of the film Free to Run Directed by Pierre Morath Switzerland, 2016, 99 minutes Today, all anybody needs to run is the determination and a pair of the right shoes. But just fifty years ago, running was viewed almost exclusively as the domain of elite male athletes who competed on tracks. With insight and propulsive energy, director Pierre Morath traces running's rise to the 1960s, examining how the liberation movements and newfound sense of personal freedom that defined the era took the sport out of the stadiums and onto the streets, and how legends like Steve Prefontaine, Fred Lebow, and Kathrine Switzer redefined running as a populist phenomenon. Original version French; English subtitles. http://freetorun.ch/ Come along to watch the film and learn more about the history of popular races and amat...

  12. Cine-Club

    CERN Multimedia

    CineClub

    2014-01-01

      On the occasion of CERN’s 60th anniversary the CERN CineClub will be showing films from all CERN member states Thursday 10 April 2014 at 20:00 CERN Council Chamber   The Bothersome Man     Directed by Jens Lien (Norway, 2006) 95 minutes   Forty-year-old Andreas arrives in a strange city with no memory of how he got there. He is presented with a job, an apartment-even a beautiful girlfriend. But before long, Andreas notices that something is wrong. The people around him seem cut off from any real emotion, and communicate only in superficialities. All this seems to be governed by a shadowy group of technicians, the ominous Caretakers’, who make sure the city runs smoothly. When they find Andreas is not adjusting to his new life, they keep an increasing watch over his activities...”The Bothersome Man” is a fantastic fable, a parable for modern society’s consumerism and obsession with ap...

  13. CERN CINE CLUB

    CERN Multimedia

    CERN CINE CLUB

    2010-01-01

    CERN CINE CLUB Thursday 24 June 2010 at 20:30 / Jeudi 24 Juin 2010 à 20:30 CERN Main Auditorium / Amphithéâtre Principal   The Raggedy Rawney By/de : Bob Hoskins (UK, 1988) - 104 min With/avec: Dexter Fletcher, Bob Hoskins, David Hill, Zoe Nathanson, Zoe Wanamaker Bob Hoskins makes his directorial debut with this lyrical, mystical fable about the strength of family and the transcendence of love. When a young military recruit named Tom goes AWOL after his first taste of battle, he must disguise himself with face paint and women’s clothing to avoid being captured by his vengeful commanding officer. He is instead discovered and taken in by Darky, the leader of an eccentric group of traveling gypsies, who thinks he is a «rawney», a half-mad, half-magical woman who brings good fortune. But when Tom begins a love affair with Darky’s daughter, he sets off a chain reaction of events that will soon put all of their lives in grave ...

  14. EPID based in vivo dosimetry system: clinical experience and results.

    Science.gov (United States)

    Celi, Sofia; Costa, Emilie; Wessels, Claas; Mazal, Alejandro; Fourquet, Alain; Francois, Pascal

    2016-05-08

    Mandatory in several countries, in vivo dosimetry has been recognized as one of the next milestones in radiation oncology. Our department has implemented clinically an EPID based in vivo dosimetry system, EPIgray, by DOSISOFT S.A., since 2006. An analysis of the measurements per linac and energy over a two-year period was performed, which included a more detailed examination per technique and treat-ment site over a six-month period. A comparison of the treatment planning system doses and the doses estimated by EPIgray shows a mean of the differences of 1.9% (± 5.2%) for the two-year period. The 3D conformal treatment plans had a mean dose difference of 2.0% (± 4.9%), while for intensity-modulated radiotherapy and volumetric-modulated arc therapy treatments the mean dose difference was -3.0 (± 5.3%) and -2.5 (± 5.2%), respectively. In addition, root cause analyses were conducted on the in vivo dosimetry measurements of two breast cancer treatment techniques, as well as prostate treatments with intensity-modulated radiotherapy and volumetric-modulated arc therapy. During the breast study, the dose differences of breast treatments in supine position were correlated to patient setup and EPID positioning errors. Based on these observations, an automatic image shift correc-tion algorithm is developed by DOSIsoft S.A. The prostate study revealed that beams and arcs with out-of-tolerance in vivo dosimetry results tend to have more complex modulation and a lower exposure of the points of interest. The statistical studies indicate that in vivo dosimetry with EPIgray has been successfully imple-mented for classical and complex techniques in clinical routine at our institution. The additional breast and prostate studies exhibit the prospects of EPIgray as an easy supplementary quality assurance tool. The validation, the automatization, and the reduction of false-positive results represent an important step toward adaptive radiotherapy with EPIgray.

  15. Motion Correction using Coil Arrays (MOCCA) for Free-Breathing Cardiac Cine MRI

    Science.gov (United States)

    Hu, Peng; Hong, Susie; Moghari, Mehdi H.; Goddu, Beth; Goepfert, Lois; Kissinger, Kraig V.; Hauser, Thomas H.; Manning, Warren J; Nezafat, Reza

    2014-01-01

    In this study, we present a motion compensation technique based on coil arrays (MOCCA) and evaluate its application in free-breathing respiratory self-gated cine MRI. MOCCA takes advantages of the fact that motion-induced changes in k-space signal are modulated by individual coil sensitivity profiles. In the proposed implementation of MOCCA self-gating for free-breathing cine MRI, the k-space center line is acquired at the beginning of each k-space segment for each cardiac cycle with 4 repetitions. For each k-space segment, the k-space center line acquired immediately before was used to select one of the 4 acquired repetitions to be included in the final self-gated cine image by calculating the cross-correlation between the k-space center line with a reference line. The proposed method was tested on a cohort of healthy adult subjects for subjective image quality and objective blood-myocardium border sharpness. The method was also tested on a cohort of patients to compare the left and right ventricular volumes and ejection fraction measurements with that of standard breath-hold cine MRI. Our data indicate that the proposed MOCCA method provides significantly improved image quality and sharpness compared to free-breathing cine without respiratory self-gating, and provides similar volume measurements compared with breath-hold cine MRI. PMID:21773986

  16. Characteristics of intra-left atrial flow dynamics and factors affecting formation of the vortex flow – analysis with phase-resolved 3-dimensional cine phase contrast magnetic resonance imaging.

    Science.gov (United States)

    Suwa, Kenichiro; Saitoh, Takeji; Takehara, Yasuo; Sano, Makoto; Nobuhara, Mamoru; Saotome, Masao; Urushida, Tsuyoshi; Katoh, Hideki; Satoh, Hiroshi; Sugiyama, Masataka; Wakayama, Tetsuya; Alley, Marcus; Sakahara, Harumi; Hayashi, Hideharu

    2015-01-01

    The intra-left atrial (LA) blood flow from pulmonary veins (PVs) to the left ventricle (LV) changes under various conditions and might affect global cardiac function. By using phase-resolved 3-dimensional cine phase contrast magnetic resonance imaging (4D-Flow), the intra-LA vortex formation was visualized and the factors affecting the intra-LA flow dynamics were examined. Thirty-two patients with or without organic heart diseases underwent 4D-Flow and transthoracic echocardiography. The intra-LA velocity vectors from each PV were post-processed to delineate streamline and pathline images. The vector images revealed intra-LA vortex formation in 20 of 32 patients. All the vortices developed during the late systolic and early diastolic phases and were directed counter-clockwise when viewed from the subjects' cranial side. The flow vectors from the right PVs lengthened predominantly toward the mitral valves and partly toward the LA appendage, whereas those from the left PVs directed rightward along the posterior wall and joined the vortex. Patients with vortex had less organic heart diseases, smaller LV and LA volume, and greater peak flow velocity and volume mainly in the left PVs, although the flow directions from each PV or PV areas did not differ. 4D-Flow can clearly visualize the intra-LA vortex formation and analyze its characteristic features. The vortex formation might depend on LV and LA volume and on flow velocity and volume from PVs.

  17. Automated x-ray/light field congruence using the LINAC EPID panel.

    Science.gov (United States)

    Polak, Wojciech; O'Doherty, Jim; Jones, Matt

    2013-03-01

    X-ray/light field alignment is a test described in many guidelines for the routine quality control of clinical linear accelerators (LINAC). Currently, the gold standard method for measuring alignment is through utilization of radiographic film. However, many modern LINACs are equipped with an electronic portal imaging device (EPID) that may be used to perform this test and thus subsequently reducing overall cost, processing, and analysis time, removing operator dependency and the requirement to sustain the departmental film processor. This work describes a novel method of utilizing the EPID together with a custom inhouse designed jig and automatic image processing software allowing measurement of the light field size, x-ray field size, and congruence between them. The authors present results of testing the method for aS1000 and aS500 Varian EPID detectors for six LINACs at a range of energies (6, 10, and 15 MV) in comparison with the results obtained from the use of radiographic film. Reproducibility of the software in fully automatic operation under a range of operating conditions for a single image showed a congruence of 0.01 cm with a coefficient of variation of 0. Slight variation in congruence repeatability was noted through semiautomatic processing by four independent operators due to manual marking of positions on the jig. Testing of the methodology using the automatic method shows a high precision of 0.02 mm compared to a maximum of 0.06 mm determined by film processing. Intraindividual examination of operator measurements of congruence was shown to vary as much as 0.75 mm. Similar congruence measurements of 0.02 mm were also determined for a lower resolution EPID (aS500 model), after rescaling of the image to the aS1000 image size. The designed methodology was proven to be time efficient, cost effective, and at least as accurate as using the gold standard radiographic film. Additionally, congruence testing can be easily performed for all four cardinal

  18. Commissioning of Portal Dosimetry and characterization of an EPID; Comissionamento de Portal Dosimetry e caracterizacao de EPID

    Energy Technology Data Exchange (ETDEWEB)

    Olbi, D.S.; Sales, C.P. [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina; Nakandakari, M.V.N., E-mail: diego.olbi@hc.fm.usp.br [Instituto do Cancer do Estado de Sao Paulo, SP (Brazil). Servico de Radioterapia

    2016-07-01

    The development of technologies compensator blocks, MLC, high dose rate accelerators, treatment planning systems, among others, permitted that new treatment techniques in radiotherapy were created. Such techniques have the capacity to modulate radiation beam fluency (IMRT, VMAT), or to deliver high doses in few fractions or unique fractions (SRS). Following the same tendency, quality control of planning became more complex. It is necessary to evaluate the fluency delivered by the accelerator. Its levels of does and its spatial distribution should co-occur with the fluency calculated by TPS. Acquisition of new detector devices in quality control of treatments is fundamental to apply techniques. Portal Vision is a device EPID has the capacity to operate either in image mode or dosimetry mode, with the allowance of Portal Dosimetry. To evaluated planning in IMRT, the device is irradiated using planning e, therefore, the fluency measured is compared with calculated fluency, through gamma analysis. The aim of this work was to perform tests of commissioning of this device. (author)

  19. [Visualization of laryngopharynx during swallowing of negative contrast media (air) with cine mode 64-row MDCT].

    Science.gov (United States)

    Fudeya, Taku; Otake, Shoichiro; Watabe, Hirotaka; Mitsuoka, Takashi; Yoshikawa, Akitoshi

    2010-05-20

    Video fluoroscopic examination of swallowing generally needs a contrast media such as a barium sulfate. Since the examination is usually performed in patients with dysphasia, there is a risk of aspiration. We tried to visualize the laryngopharynx during swallowing of negative contrast media (air) with 64-row multi-detector computed tomography (64-MDCT). Cine mode 64-MDCT was performed to visualize the laryngopharynx in 4 healthy volunteers during swallowing of negative contrast media (air). The data were converted to three-dimensional (3D) images of 2 conditions (air and bone) and sagittal images of the soft tissue condition at a workstation. These images were sent to a personal computer and modeled to 3D cine images with Digital Imaging and Communication in Medicine (DICOM) Viewer and Quick Time Player. 3D cine images demonstrated movements of the epiglottis, vallecula, piriform sinus, tongue, pharyngeal wall, hyoid bone and thyroid cartilage.

  20. Quality control program of multi-leaf collimation based EPID for teams with Rapidarc; Programa de control de calidad del sistema de colimacion Multilamina basado en EPID para equipos con Rapidarc

    Energy Technology Data Exchange (ETDEWEB)

    Pujades Claumarchirant, M. C.; Richart Sancho, J.; Gimeno Olmos, J.; Lliso Valverde, F.; Carmona Mesenguer, V.; Garcia Martinez, M. T.; Palomo Llinares, R.; Ballester Pallares, F.; Perez Calatayud, J.

    2013-07-01

    The objective of this work is to show a collection of different recommendations on the control of quality of collimation multi-leaf system and present the selection of tests based on the electronic imaging device (EPID) portal that have decided to establish in our Center, where in addition to the requirements of quality assurance generic for collimation multi-leaf system quality control methods have been included for RapidArc. (Author)

  1. Verification of PTV margins for IMRT prostate cancer using EPID; Verificacao das margens de PTV para IMRT de cancer de prostata utilizando EPID

    Energy Technology Data Exchange (ETDEWEB)

    Leidens, Matheus; Santos, Romulo R.; Estacio, Daniela R. [Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil). Hospital Sao Lucas. Servico de Fisica Medica; Silva, Ana Maria Marques da, E-mail: matheus_leidens@hotmail.com [Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil). Faculdade de Fisica

    2014-12-15

    The aim of this work is to present the results of a strategy to define the PTV margins for patients with prostate cancer treated with IMRT technique, due to geometrical uncertainties associated with the planned placement. 341 images of 31 patients in supine position, before applying the fractions, were obtained using an EPID attached to a linear accelerator, where only setup errors were studied. The displacements were analyzed in relation to the AP (antero-posterior), SI (superior-inferior) and LR (left-right) directions. The distribution pattern of systematic displacement deviation values were 0.12 cm, 0.06 cm, 0.02 cm and the standard deviation of the distribution of random deviations was 0.62 cm, 0.53 cm, and 0.24 cm in the AP, SI and LR directions, respectively. Data evaluation, according to Stroom and Heijmen’s method, suggests that PTV margins should be 0.66 cm in the AP direction, 0.49 cm in the SI direction and 0.20 cm in the LR direction. These data show a high reproducibility in the positioning of patients, given by a method for the correction of planned relative to the bony anatomy checked with the EPID position. (author)

  2. Comparison of left and right ventricular ejection and filling parameters by fast cine MR imaging in breath-hold technique: clinical study of 42 patients with cardiomyopathy and coronary heart disease

    International Nuclear Information System (INIS)

    Rominger, M.B.; Bachmann, G.F.; Geuer, M.; Puzik, M.; Rau, W.S.; Ricken, W.W.

    1999-01-01

    Purpose: Quantification of left and right ventricular filling and ejection of localized and diffuse heart diseases with fast cine MR imaging in breath-hold technique. Methods: 42 patients (14 idiopathic dilated cardiomyopathies (DCM), 13 hypertrophic cardiomyopathies (HCM) and 15 coronary artery diseases (CAD)) and 10 healthy volunteers were examined. Time-volume-curves of three left ventricular and one right ventricular slices were evaluated and peak ejection and filling rates (PER, PFR end-diastolic volume (EDV)/s) time to PER and PFR (TPER, TPFR ms) and time of end-systole (TSYS in % RR-intervall) were calculated. Results: There were significant regional and left-/right-sided differences of the filling and ejection of both ventricles within and between the different groups. In DCM the left ventricular PFR was reduced (DCM 3.1 EDV/s; volunteers 4.9 EDV/s) and Z-SYS prolonged (DCM 50.1%; volunteers 35.4%). In CAD there were localized decreased filling rates in comparison to the normal volunteer group (left ventricle: basal: 2.9 and 6.3 EDV/s, apical: 4.4 and 6.3 EDV/s; right ventricle: 3.6 and 5.7 EDV/s). HCM typically showed an isovolumetric lengthening of the endsystole. Conclusions: Cardiac MR imaging in breath-hold technique is suitable for measuring contraction and relaxation disturbances of localized and diffuse heart diseases by means of ejection and filling volume indices. (orig.) [de

  3. Feasibility of vocal fold abduction and adduction assessment using cine-MRI.

    Science.gov (United States)

    Baki, Marina Mat; Menys, Alex; Atkinson, David; Bassett, Paul; Morley, Simon; Beale, Timothy; Sandhu, Guri; Naduvilethil, Georgekutty; Stevenson, Nicola; Birchall, Martin A; Punwani, Shonit

    2017-02-01

    Determine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI) METHODS: Cine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC). VF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44). Cine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability. • Cine-MRI is used to assess vocal folds (VFs) mobility: abduction and adduction. • New quantitative metrics are derived from VF position and abduction potential. • Cine-MRI able to depict the difference between normal and abnormal VF mobility. • Cine-MRI derived quantitative metrics have good repeatability.

  4. ¿Cine para qué? ¿Cine para quién?

    OpenAIRE

    Lluna, Catalina; Perazzo, Matías; Tegiachi, Luz

    2016-01-01

    El “cine arte”, “cine de autor” o sencillamente el cine independiente parece atenerse a reglas muy distintas que las películas comerciales. ¿Qué buscan los realizadores independientes? ¿En quién(es) piensan a la hora de desarrollar sus películas? Pensamos algunas de estas cuestiones a partir del análisis de una instancia del proyecto de tesis de Matías Perazzo, estudiante de cine.

  5. EPID-based in vivo dosimetry for stereotactic body radiotherapy of non-small cell lung tumors: Initial clinical experience.

    Science.gov (United States)

    Consorti, R; Fidanzio, A; Brainovich, V; Mangiacotti, F; De Spirito, M; Mirri, M A; Petrucci, A

    2017-10-01

    EPID-based in vivo dosimetry (IVD) has been implemented for stereotactic body radiotherapy treatments of non-small cell lung cancer to check both isocenter dose and the treatment reproducibility comparing EPID portal images. 15 patients with lung tumors of small dimensions and treated with volumetric modulated arc therapy were enrolled for this initial experience. IVD tests supplied ratios R between in vivo reconstructed and planned isocenter doses. Moreover a γ-like analysis between daily EPID portal images and a reference one, in terms of percentage of points with γ-value smaller than 1, P γlevels of 5% for R ratio, P γlevel, and an average P γ90%. Paradigmatic discrepancies were observed in three patients: a set-up error and a patient morphological change were identified thanks to CBCT image analysis whereas the third discrepancy was not fully justified. This procedure can provide improved patient safety as well as a first step to integrate IVD and CBCT dose recalculation. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  6. Feasibility of free-breathing, GRAPPA-based, real-time cardiac cine assessment of left-ventricular function in cardiovascular patients at 3 T

    International Nuclear Information System (INIS)

    Zhu, Xiaomei; Schwab, Felix; Marcus, Roy; Hetterich, Holger; Theisen, Daniel; Kramer, Harald; Notohamiprodjo, Mike; Schlett, Christopher L.; Nikolaou, Konstantin; Reiser, Maximilian F.

    2015-01-01

    Highlights: • Grappa-based real time cine cardiac MRI is feasible for assessment of left ventricular function. • Significant underestimation of systolic function, peak ejection and filling rates needs to be considered. • Heart rate is the only positive predictor of the deviation of obtained parameters. - Abstract: Objectives: To determine the feasibility of free-breathing, GRAPPA-based, real-time (RT) cine 3 T cardiac magnetic resonance imaging (MRI) with high acceleration factors for the assessment of left-ventricular function in a cohort of patients as compared to conventional segmented cine imaging. Materials and methods: In this prospective cohort study, subjects with various cardiac conditions underwent MRI involving two RT cine sequences (high resolution and low resolution) and standard segmented cine imaging. Standard qualitative and quantitative parameters of left-ventricular function were quantified. Results: Among 25 subjects, 24 were included in the analysis (mean age: 50.5 ± 21 years, 67% male, 25% with cardiomyopathy). RT cine derived quantitative parameters of volumes and left ventricular mass were strongly correlated with segmented cine imaging (intraclass correlation coefficient [ICC]: >0.72 for both RT cines) but correlation for peak ejection and filling rates were moderate to poor for both RT cines (ICC < 0.40). Similarly, RT cines significantly underestimated peak ejection and filling rates (>103.2 ± 178 ml/s). Among patient-related factors, heart rate was strongly predictive for deviation of measurements (p < 0.05). Conclusions: RT cine MRI at 3 T is feasible for qualitative and quantitative assessment of left ventricular function for low and high-resolution sequences but results in significant underestimation of systolic function, peak ejection and filling rates

  7. Evaluation of MLC leaf positioning using a scanning liquid ionization chamber EPID

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Mohammad [Department of Medical Physics, Royal Adelaide Hospital, Adelaide, SA 5000 (Australia); Bezak, Eva [Department of Medical Physics, Royal Adelaide Hospital, Adelaide, SA 5000 (Australia)

    2007-01-07

    A method was developed to determine the accuracy of multileaf collimator (MLC) positioning using transmitted dose maps measured by a scanning liquid ionization chamber electronic portal imaging device (SLIC-EPID). Several MLC fields were designed, using the Varian C-series standard MLC-80, as reference fields for open fields. The MLC leaves were then shifted from the reference positions along the direction of MLC leaf movement towards the central axis from 0.1 to 1.6 mm. The electronic portal images (EPIs), acquired for each case, were converted to two-dimensional dose maps using an appropriate calibration method and the relative dose difference maps were then calculated. The experiment was then performed at non-zero gantry angles in the presence of an anthropomorphic phantom for typical prostate and head and neck fields. Several standard edge detection algorithms were also used in order to find the shifted MLC leaf position. In addition, the short-term reproducibility of MLC leaf positioning was evaluated using the above-mentioned methods. It was found that the relationship between the relative dose difference and MLC leaf spatial displacement is linear. A variation of 0.2 mm in leaf position leads to approximately 4% change in the relative dose values for open fields. The variation of the relative dose difference for phantom studies depends on the phantom positioning and the EPI normalization. From the standard edge detection algorithms, used in the current study, the 'Canny' algorithm was found to be the optimum method to identify the minimum detectable MLC leaf displacements with a precision of approximately 0.1 mm for all cases. However, the result of edge detection algorithms generally is binary and there is no additional information compared to the relative dose maps. The reproducibility of MLC positions was found to be within 0.3 mm. In conclusion, a SLIC-EPID can be used for regular quality assurance (QA) of MLC leaf positioning. Despite

  8. Paired inspiratory/expiratory spiral CT and continuous respiration cine CT in the diagnosis of tracheal instability

    International Nuclear Information System (INIS)

    Heussel, C.P.; Schreiber, W.; Thelen, M.; Kauczor, H.U.; Hafner, B.; Lill, J.

    2001-01-01

    In tracheo- and bronchomalacia, localisation and determination of collapse is necessary for planning of surgical procedure. We compared inspiratory and expiratory spiral CT, cine CT, bronchoscopy, exemplary cine MR, and evaluated the clinical relevance. Twenty-nine patients (2 follow-ups; mean age 61 years, age range 27-85 years) with suspected or verified tracheal stenosis or collapse (post-tracheotomy: n=17; neoplasm: n=5; other: n=7) underwent paired breath-hold inspiratory and expiratory spiral CT. Forty-five additional cine CT were performed at 1-4 levels (mean 1.5) during continuous respiration (increment 100 ms) to clarify respiratory collapse. The tracheal cross-sectional diameters of both techniques were calculated. Comparison with bronchoscopy, follow-up, and influence upon therapy were evaluated retrospectively. Exemplary comparison with cine MR (8 frames/s) was done in 3 cases. In addition to bronchoscopy, further information concerning localisation, extent, collapse, stability of the tracheal wall, distal portions of the stenosis and extraluminal compressions were obtained. A significantly higher degree and more pathological collapses (>50%) were seen using cine CT (38%) compared with paired spiral CT (13%; degree: p<0.0001; number: p<0.001). The findings changed the further therapeutic procedure in 16 of 29 patients. Further stenoses were excluded and bronchoscopy was verified in another 13 of 29. Temporal resolution of cine CT and cine MR is sufficient; however, spatial resolution of cine MR is inferior. Paired inspiratory and expiratory spiral CT localises tracheal stenoses and demonstrates relevant extraluminal compression. Significantly improved evaluation of respiratory collapse and further information of localised tracheal instability is obtained by cine CT. Cine MR promises more functional information especially due to free choice of imaging plane. (orig.)

  9. Feasibility of free-breathing, GRAPPA-based, real-time cardiac cine assessment of left-ventricular function in cardiovascular patients at 3T.

    Science.gov (United States)

    Zhu, Xiaomei; Schwab, Felix; Marcus, Roy; Hetterich, Holger; Theisen, Daniel; Kramer, Harald; Notohamiprodjo, Mike; Schlett, Christopher L; Nikolaou, Konstantin; Reiser, Maximilian F; Bamberg, Fabian

    2015-05-01

    To determine the feasibility of free-breathing, GRAPPA-based, real-time (RT) cine 3T cardiac magnetic resonance imaging (MRI) with high acceleration factors for the assessment of left-ventricular function in a cohort of patients as compared to conventional segmented cine imaging. In this prospective cohort study, subjects with various cardiac conditions underwent MRI involving two RT cine sequences (high resolution and low resolution) and standard segmented cine imaging. Standard qualitative and quantitative parameters of left-ventricular function were quantified. Among 25 subjects, 24 were included in the analysis (mean age: 50.5±21 years, 67% male, 25% with cardiomyopathy). RT cine derived quantitative parameters of volumes and left ventricular mass were strongly correlated with segmented cine imaging (intraclass correlation coefficient [ICC]: >0.72 for both RT cines) but correlation for peak ejection and filling rates were moderate to poor for both RT cines (ICCcines significantly underestimated peak ejection and filling rates (>103.2±178 ml/s). Among patient-related factors, heart rate was strongly predictive for deviation of measurements (pcine MRI at 3T is feasible for qualitative and quantitative assessment of left ventricular function for low and high-resolution sequences but results in significant underestimation of systolic function, peak ejection and filling rates. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Holistic segmentation of the lung in cine MRI.

    Science.gov (United States)

    Kovacs, William; Hsieh, Nathan; Roth, Holger; Nnamdi-Emeratom, Chioma; Bandettini, W Patricia; Arai, Andrew; Mankodi, Ami; Summers, Ronald M; Yao, Jianhua

    2017-10-01

    Duchenne muscular dystrophy (DMD) is a childhood-onset neuromuscular disease that results in the degeneration of muscle, starting in the extremities, before progressing to more vital areas, such as the lungs. Respiratory failure and pneumonia due to respiratory muscle weakness lead to hospitalization and early mortality. However, tracking the disease in this region can be difficult, as current methods are based on breathing tests and are incapable of distinguishing between muscle involvements. Cine MRI scans give insight into respiratory muscle movements, but the images suffer due to low spatial resolution and poor signal-to-noise ratio. Thus, a robust lung segmentation method is required for accurate analysis of the lung and respiratory muscle movement. We deployed a deep learning approach that utilizes sequence-specific prior information to assist the segmentation of lung in cine MRI. More specifically, we adopt a holistically nested network to conduct image-to-image holistic training and prediction. One frame of the cine MRI is used in the training and applied to the remainder of the sequence ([Formula: see text] frames). We applied this method to cine MRIs of the lung in the axial, sagittal, and coronal planes. Characteristic lung motion patterns during the breathing cycle were then derived from the segmentations and used for diagnosis. Our data set consisted of 31 young boys, age [Formula: see text] years, 15 of whom suffered from DMD. The remaining 16 subjects were age-matched healthy volunteers. For validation, slices from inspiratory and expiratory cycles were manually segmented and compared with results obtained from our method. The Dice similarity coefficient for the deep learning-based method was [Formula: see text] for the sagittal view, [Formula: see text] for the axial view, and [Formula: see text] for the coronal view. The holistic neural network approach was compared with an approach using Demon's registration and showed superior performance. These

  11. Dose calculation with respiration-averaged CT processed from cine CT without a respiratory surrogate

    International Nuclear Information System (INIS)

    Riegel, Adam C.; Ahmad, Moiz; Sun Xiaojun; Pan Tinsu

    2008-01-01

    Dose calculation for thoracic radiotherapy is commonly performed on a free-breathing helical CT despite artifacts caused by respiratory motion. Four-dimensional computed tomography (4D-CT) is one method to incorporate motion information into the treatment planning process. Some centers now use the respiration-averaged CT (RACT), the pixel-by-pixel average of the ten phases of 4D-CT, for dose calculation. This method, while sparing the tedious task of 4D dose calculation, still requires 4D-CT technology. The authors have recently developed a means to reconstruct RACT directly from unsorted cine CT data from which 4D-CT is formed, bypassing the need for a respiratory surrogate. Using RACT from cine CT for dose calculation may be a means to incorporate motion information into dose calculation without performing 4D-CT. The purpose of this study was to determine if RACT from cine CT can be substituted for RACT from 4D-CT for the purposes of dose calculation, and if increasing the cine duration can decrease differences between the dose distributions. Cine CT data and corresponding 4D-CT simulations for 23 patients with at least two breathing cycles per cine duration were retrieved. RACT was generated four ways: First from ten phases of 4D-CT, second, from 1 breathing cycle of images, third, from 1.5 breathing cycles of images, and fourth, from 2 breathing cycles of images. The clinical treatment plan was transferred to each RACT and dose was recalculated. Dose planes were exported at orthogonal planes through the isocenter (coronal, sagittal, and transverse orientations). The resulting dose distributions were compared using the gamma (γ) index within the planning target volume (PTV). Failure criteria were set to 2%/1 mm. A follow-up study with 50 additional lung cancer patients was performed to increase sample size. The same dose recalculation and analysis was performed. In the primary patient group, 22 of 23 patients had 100% of points within the PTV pass γ criteria

  12. PA/Lateral chest X-ray is equivalent to cine-fluoroscopy for the detection of conductor externalization in defibrillation leads.

    Science.gov (United States)

    Steinberg, Christian; Sarrazin, Jean-François; Philippon, François; Champagne, Jean; Molin, Franck; Nault, Isabelle; Blier, Louis; Bouchard, Marc-André; Arsenault, Jean; O'Hara, Gilles

    2015-01-01

    Riata™ and Riata ST defibrillation leads (St. Jude Medical, Sylmar, CA, USA) are susceptible to insulation defects with conductor externalization. Cine-fluoroscopy is considered to be the gold standard for the documentation of insulation defects, but similar detection rates have been reported for posterior-anterior (PA)/lateral chest x-ray (CXR) with zooming. Prospective single-center study to assess the diagnostic equivalence of a PA/lateral CXR with zooming for the detection of Riata insulation defects in a direct comparison to cine-fluoroscopy. Seventy-eight consecutive patients underwent 3-view cine-fluoroscopy and a PA/lateral CXR. All CXRs and cine-fluoroscopy images were reviewed by blinded electrophysiologists and staff radiologists. Forty-four of 78 patients had an abnormal cine-fluoroscopy (56%). The diagnostic correlation between PA/lateral CXR and cine-fluoroscopy was excellent (κ = 0.90; 95% confidence interval 0.80-1.00). PA/lateral CXR was equivalent to cine-fluoroscopy for the detection of conductor externalization showing a sensitivity of 97.7% and a specificity of 91.2%. The mean radiation effective dose of CXR was significantly lower compared to cine-fluoroscopy (0.09 millisievert [mSV] vs 0.85 ± 0.47 mSv; P cine-fluoroscopy for the detection of Riata insulation defects and should be considered as the preferred screening method. ©2014 Wiley Periodicals, Inc.

  13. Use of an amorphous silicon EPID for measuring MLC calibration at varying gantry angle

    International Nuclear Information System (INIS)

    Clarke, M F; Budgell, G J

    2008-01-01

    Amorphous silicon electronic portal imaging devices (EPIDs) are used to perform routine quality control (QC) checks on the multileaf collimators (MLCs) at this centre. Presently, these checks are performed at gantry angle 0 0 and are considered to be valid for all other angles. Since therapeutic procedures regularly require the delivery of MLC-defined fields to the patient at a wide range of gantry angles, the accuracy of the QC checks at other gantry angles has been investigated. When the gantry is rotated to angles other than 0 0 it was found that the apparent pixel size measured using the EPID varies up to a maximum value of 0.0015 mm per pixel due to a sag in the EPID of up to 9.2 mm. A correction factor was determined using two independent methods at a range of gantry angles between 0 deg. and 360 deg. The EPID was used to measure field sizes (defined by both x-jaws and MLC) at a range of gantry angles and, after this correction had been applied, any residual gravitational sag was studied. It was found that, when fields are defined by the x-jaws and y-back-up jaws, no errors of greater than 0.5 mm were measured and that these errors were no worse when the MLC was used. It was therefore concluded that, provided the correction is applied, measurements of the field size are, in practical terms, unaffected by gantry angle. Experiments were also performed to study how the reproducibility of individual leaves is affected by gantry angle. Measurements of the relative position of each individual leaf (minor offsets) were performed at a range of gantry angles and repeated three times. The position reproducibility was defined by the RMS error in the position of each leaf and this was found to be 0.24 mm and 0.21 mm for the two leaf banks at a gantry angle of 0 0 . When measurements were performed at a range of gantry angles, these reproducibility values remained within 0.09 mm and 0.11 mm. It was therefore concluded that the calibration of the Elekta MLC is stable at

  14. Cine MR evaluation of the inferior vena cava in patients with Simon Nitinol filters

    International Nuclear Information System (INIS)

    Steinberg, F.L.; Denham, J.S.; Geller, S.C.; Manickas, A.P.; Athanasoulis, C.A.; Cohn, M.J.; Taafe, J.L.; Waltman, A.C.

    1988-01-01

    This study evaluated the ability of cine MR imaging to detect thrombus in the inferior vena cava (IVC) of seven patients after percutaneous implantation of Simon-Nitinol filters. Cine MR imagine was performed at 0.6 T. Sixteen phases of the cardiac cycle were obtained in sagittal or coronal projection with echo time equal to 15 msec, repetition time equal to 40 msec, and flip angle of 40 0 . The section thickness was 7.5 mm. Blood flow in the IVC had high signal intensity that varied with the cardiac cycle. Thrombus had a range of signal intensities, but there was no variation of signal intensity during the cardiac cycle. The Simon-Nitinol filter caused no detectable image degradation. Cine MR imaging had the ability to detect thrombosis of the IVC below the filter and thrombus above the filter, and localize the position of the filter

  15. Development of a software of VMAT delivery using EPID

    International Nuclear Information System (INIS)

    Arumugam, Sankar; Xing, Aitang; Jameson, Michael; Holloway, Lois; Goozee, Gary

    2011-01-01

    Full text: Volumetric Modulated Arc Therapy (VMAT) is more complex than standard IMRT, requiring new methodology to evaluate delivery accuracy. Here, we present the development of methodology and a software tool to perform control point based verification of VMAT delivery using an EPID. Individual segment dose comparison allows the verification of VMAT deli very accuracy for individual control-points. An in-house software tool was developed to predict the individual segment dose as measured by EPID for Pinnacle (Philips) generated VMAT plans. The VMAT plans were delivered using an Elekta-synergy accelerator and the segment doses were measured using EPID. A normalised dose comparison of measured and predicted doses was performed using gamma analysis with 3% dose tolerance and 3 mm DTA. The sensitivity of the proposed methodology in detecting delivery errors was studied by delivering a standard intensity pattern with a preset dose error of 4 and 5% in two of its eight control-points. Four clinical plans were also tested using this methodology. The developed software accurately predicts the EPID dose by considering all possible leaf trajectories in VMAT delivery. The mean gamma value and percentage of pixels exceeding the gamma tolerance for a segment with and without delivery errors are shown in Table. From the tabulated values it is evident that the proposed methodology is sensitive in detecting delivery errors above 3% tolerance level. The clinical plans were successfully validated showing a maximum 2.5% of pixels exceeding gamma tolerance. Methodology and a software were successfully developed to perform control-point validation of VMAT delivery using an EPID. Set error in Delivery (%) Mean gamma value% of pixels exceeding Gamma tolerance 0 0.40 1.240.5417.050.6221.8.

  16. Comparison of forward- and back-projection in vivo EPID dosimetry for VMAT treatment of the prostate

    Science.gov (United States)

    Bedford, James L.; Hanson, Ian M.; Hansen, Vibeke N.

    2018-01-01

    In the forward-projection method of portal dosimetry for volumetric modulated arc therapy (VMAT), the integrated signal at the electronic portal imaging device (EPID) is predicted at the time of treatment planning, against which the measured integrated image is compared. In the back-projection method, the measured signal at each gantry angle is back-projected through the patient CT scan to give a measure of total dose to the patient. This study aims to investigate the practical agreement between the two types of EPID dosimetry for prostate radiotherapy. The AutoBeam treatment planning system produced VMAT plans together with corresponding predicted portal images, and a total of 46 sets of gantry-resolved portal images were acquired in 13 patients using an iViewGT portal imager. For the forward-projection method, each acquisition of gantry-resolved images was combined into a single integrated image and compared with the predicted image. For the back-projection method, iViewDose was used to calculate the dose distribution in the patient for comparison with the planned dose. A gamma index for 3% and 3 mm was used for both methods. The results were investigated by delivering the same plans to a phantom and repeating some of the deliveries with deliberately introduced errors. The strongest agreement between forward- and back-projection methods is seen in the isocentric intensity/dose difference, with moderate agreement in the mean gamma. The strongest correlation is observed within a given patient, with less correlation between patients, the latter representing the accuracy of prediction of the two methods. The error study shows that each of the two methods has its own distinct sensitivity to errors, but that overall the response is similar. The forward- and back-projection EPID dosimetry methods show moderate agreement in this series of prostate VMAT patients, indicating that both methods can contribute to the verification of dose delivered to the patient.

  17. Miércoles al cine

    OpenAIRE

    Aguado Franco, Juan Carlos

    2014-01-01

    Se analiza un caso concreto de demanda ante una iniciativa empresarial: los miércoles al cine. Se analiza un caso concreto de demanda ante una iniciativa empresarial: los miércoles al cine. Fundamentos del Análisis Económico

  18. Comparison of standard, prone and cine MRI in the evaluation of tethered cord

    International Nuclear Information System (INIS)

    Singh, Sukhjinder; Kline-Fath, Beth; Racadio, Judy M.; Bierbrauer, Karin; Salisbury, Shelia; Macaluso, Maurizio; Jackson, Elizabeth C.; Egelhoff, John C.

    2012-01-01

    Tethered cord syndrome (TCS) is defined by abnormal traction on the spinal cord that confines its movement. Surgical cord release usually stops neurological deterioration; therefore, early and accurate neuroradiological diagnosis is important. Supine MRI is the imaging modality of choice, but prone MRI and cine MRI can demonstrate cord movement. We compared the diagnostic accuracies of standard MRI, prone MRI and cine MRI in patients with clinical suspicion of TCS and evaluated inter-reader reliability for MR imaging. Children who underwent MRI for suspicion of TCS were retrospectively identified. Supine, prone and cine MRI studies were re-read by two pediatric neuroradiologists. Conus level, filum appearance and cord movement were documented. Thirteen of 49 children had tethered cord documented at surgery. Conus level had the highest diagnostic accuracy (sensitivity 69-77%, specificity 94%, positive predictive value 82-83%, negative predictive value 89-92%, correct diagnosis 88-90%) and highest between-reader concordance (98%). Prone and cine MRI did not add to the accuracy of the supine imaging. Conus level provides the highest diagnostic accuracy and inter-reader reliability in TCS. Until a larger series is evaluated, it remains questionable whether prone or cine MRI provides enough additional diagnostic information to warrant routine use. (orig.)

  19. Megavoltage conebeam CT cine as final verification of treatment plan in lung stereotactic body radiotherapy.

    Science.gov (United States)

    Kudithipudi, Vijay; Gayou, Olivier; Colonias, Athanasios

    2016-06-01

    To analyse the clinical impact of megavoltage conebeam computed tomography (MV-CBCT) cine on internal target volume (ITV) coverage in lung stereotactic body radiotherapy (SBRT). One hundred and six patients received lung SBRT. All underwent 4D computed tomography simulation followed by treatment via image guided 3D conformal or intensity modulated radiation. Prior to SBRT, all patients underwent MV-CBCT cine, in which raw projections are displayed as beam's-eye-view fluoroscopic series with the planning target volume (PTV) projected onto each image, enabling verification of tumour motion relative to the PTV and assessment of adequacy of treatment margin. Megavoltage conebeam computed tomography cine was completed 1-2 days prior to SBRT. Four patients (3.8%) had insufficient ITV coverage inferiorly at cine review. All four plans were changed by adding 5 mm on the PTV margin inferiorly. The mean change in PTV volumes was 3.9 cubic centimetres (cc) (range 1.85-6.32 cc). Repeat cine was performed after plan modification to ensure adequate PTV coverage in the modified plans. PTV margin was adequate in the majority of patients with this technique. MV-CBCT cine did show insufficient coverage in a small subset of patients. Insufficient PTV margins may be a function of 4D CT simulation inadequacies or deficiencies in visualizing the ITV inferior border in the full-inhale phase. MV-CBCT cine is a valuable tool for final verification of PTV margins. © 2016 The Royal Australian and New Zealand College of Radiologists.

  20. TU-C-BRE-10: A Streamlined Approach to EPID Transit Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Morris, B; Fontenot, J [Louisiana State University, Baton Rouge, LA (United States); Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States)

    2014-06-15

    Purpose: To investigate the feasibility of a simple and efficient transit dosimetry method using the electronic portal imaging device (EPID) for dose delivery error detection and prevention. Methods: In the proposed method, 2D reference transit images are generated for comparison with online images acquired during treatment. Reference transit images are generated by convolving through-air EPID measurements of each field with pixel-specific kernels selected from a library of pre-calculated Monte Carlo pencil kernels of varying radiological thickness. The kernel used for each pixel is selected based on the calculated radiological thickness of the patient along a line joining the pixel and the virtual source. The accuracy of the technique was evaluated in flat homogeneous and heterogeneous plastic water phantoms, a heterogeneous cylindrical phantom, and an anthropomorphic head phantom. Gamma criteria of 3%/3 mm was used to quantify the accuracy of the technique for the various cases. Results: An average of 99.9% and 99.7% of the points in the comparison between the measured and predicted images passed a 3%/3mm gamma for the homogeneous and heterogeneous plastic water phantoms, respectively. 97.1% of the points passed for the analysis of the heterogeneous cylindrical phantom. For the anthropomorphic head phantom, an average of 97.8% of points passed the 3%/3mm gamma criteria for all field sizes. Failures were observed primarily in areas of drastic thickness or material changes and at the edges of the fields. Conclusion: The data suggest that the proposed transit dosimetry method is a feasible approach to in vivo dose monitoring. Future research efforts could include implementation for more complex fields and sensitivity testing of the method to setup errors and changes in anatomy. Oncology Data Systems provided partial funding support but did not participate in the collection or analysis of data.

  1. Compressed sensing reconstruction of cardiac cine MRI using golden angle spiral trajectories.

    Science.gov (United States)

    Tolouee, Azar; Alirezaie, Javad; Babyn, Paul

    2015-11-01

    In dynamic cardiac cine Magnetic Resonance Imaging (MRI), the spatiotemporal resolution is limited by the low imaging speed. Compressed sensing (CS) theory has been applied to improve the imaging speed and thus the spatiotemporal resolution. The purpose of this paper is to improve CS reconstruction of under sampled data by exploiting spatiotemporal sparsity and efficient spiral trajectories. We extend k-t sparse algorithm to spiral trajectories to achieve high spatio temporal resolutions in cardiac cine imaging. We have exploited spatiotemporal sparsity of cardiac cine MRI by applying a 2D+time wavelet-Fourier transform. For efficient coverage of k-space, we have used a modified version of multi shot (interleaved) spirals trajectories. In order to reduce incoherent aliasing artifact, we use different random undersampling pattern for each temporal frame. Finally, we have used nonuniform fast Fourier transform (NUFFT) algorithm to reconstruct the image from the non-uniformly acquired samples. The proposed approach was tested in simulated and cardiac cine MRI data. Results show that higher acceleration factors with improved image quality can be obtained with the proposed approach in comparison to the existing state-of-the-art method. The flexibility of the introduced method should allow it to be used not only for the challenging case of cardiac imaging, but also for other patient motion where the patient moves or breathes during acquisition. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Feasibility of vocal fold abduction and adduction assessment using cine-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Baki, Marina Mat [National University of Malaysia, Faculty of Medicine, Kuala Lumpur (Malaysia); Menys, Alex; Morley, Simon; Beale, Timothy [University College London, Centre for Medical Imaging, London (United Kingdom); Atkinson, David; Punwani, Shonit [University College London, Centre for Medical Imaging, London (United Kingdom); Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London (United Kingdom); Bassett, Paul [University College London, London (United Kingdom); Sandhu, Guri [Charing Cross Hospital, Imperial College Healthcare NHS Trust, London (United Kingdom); Naduvilethil, Georgekutty; Stevenson, Nicola [Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London (United Kingdom); Birchall, Martin A. [Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London (United Kingdom); University of California, Davis, Department of Otolaryngology, Davis, CA (United States); University College London, Ear Institute, London (United Kingdom)

    2017-02-15

    Determine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI) Cine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC). VF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44). Cine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability. (orig.)

  3. Feasibility of vocal fold abduction and adduction assessment using cine-MRI

    International Nuclear Information System (INIS)

    Baki, Marina Mat; Menys, Alex; Morley, Simon; Beale, Timothy; Atkinson, David; Punwani, Shonit; Bassett, Paul; Sandhu, Guri; Naduvilethil, Georgekutty; Stevenson, Nicola; Birchall, Martin A.

    2017-01-01

    Determine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI) Cine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC). VF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44). Cine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability. (orig.)

  4. Cine y turismo: intersecciones polivalentes.

    OpenAIRE

    Rey-Reguillo, Antonia del

    2012-01-01

    Con el objeto de servir de introducción a los tres artículos que componen el dossier sobre Cine y Turismo contenido en la revista, este texto reflexiona someramente sobre el amplio abanico de intersecciones existente entre las industrias cinematográfica y turística ajustándose al caso concreto de la producción fílmica española considerada en tres etapas concretas: los documentales etnoturísticos surgidos en el período histórico correspondiente a la Segunda República, el documental 'España ins...

  5. Cine Computed Tomography Without Respiratory Surrogate in Planning Stereotactic Radiotherapy for Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Riegel, Adam C. B.A.; Chang, Joe Y.; Vedam, Sastry S.; Johnson, Valen; Chi, Pai-Chun Melinda; Pan, Tinsu

    2009-01-01

    Purpose: To determine whether cine computed tomography (CT) can serve as an alternative to four-dimensional (4D)-CT by providing tumor motion information and producing equivalent target volumes when used to contour in radiotherapy planning without a respiratory surrogate. Methods and Materials: Cine CT images from a commercial CT scanner were used to form maximum intensity projection and respiratory-averaged CT image sets. These image sets then were used together to define the targets for radiotherapy. Phantoms oscillating under irregular motion were used to assess the differences between contouring using cine CT and 4D-CT. We also retrospectively reviewed the image sets for 26 patients (27 lesions) at our institution who had undergone stereotactic radiotherapy for Stage I non-small-cell lung cancer. The patients were included if the tumor motion was >1 cm. The lesions were first contoured using maximum intensity projection and respiratory-averaged CT image sets processed from cine CT and then with 4D-CT maximum intensity projection and 10-phase image sets. The mean ratios of the volume magnitude were compared with intraobserver variation, the mean centroid shifts were calculated, and the volume overlap was assessed with the normalized Dice similarity coefficient index. Results: The phantom studies demonstrated that cine CT captured a greater extent of irregular tumor motion than did 4D-CT, producing a larger tumor volume. The patient studies demonstrated that the gross tumor defined using cine CT imaging was similar to, or slightly larger than, that defined using 4D-CT. Conclusion: The results of our study have shown that cine CT is a promising alternative to 4D-CT for stereotactic radiotherapy planning

  6. Left Ventricular Function Evaluation on a 3T MR Scanner with Parallel RF Transmission Technique: Prospective Comparison of Cine Sequences Acquired before and after Gadolinium Injection.

    Science.gov (United States)

    Caspar, Thibault; Schultz, Anthony; Schaeffer, Mickaël; Labani, Aïssam; Jeung, Mi-Young; Jurgens, Paul Thomas; El Ghannudi, Soraya; Roy, Catherine; Ohana, Mickaël

    To compare cine MR b-TFE sequences acquired before and after gadolinium injection, on a 3T scanner with a parallel RF transmission technique in order to potentially improve scanning time efficiency when evaluating LV function. 25 consecutive patients scheduled for a cardiac MRI were prospectively included and had their b-TFE cine sequences acquired before and right after gadobutrol injection. Images were assessed qualitatively (overall image quality, LV edge sharpness, artifacts and LV wall motion) and quantitatively with measurement of LVEF, LV mass, and telediastolic volume and contrast-to-noise ratio (CNR) between the myocardium and the cardiac chamber. Statistical analysis was conducted using a Bayesian paradigm. No difference was found before or after injection for the LVEF, LV mass and telediastolic volume evaluations. Overall image quality and CNR were significantly lower after injection (estimated coefficient cine after > cine before gadolinium: -1.75 CI = [-3.78;-0.0305], prob(coef>0) = 0% and -0.23 CI = [-0.49;0.04], prob(coef>0) = 4%) respectively), but this decrease did not affect the visual assessment of LV wall motion (cine after > cine before gadolinium: -1.46 CI = [-4.72;1.13], prob(coef>0) = 15%). In 3T cardiac MRI acquired with parallel RF transmission technique, qualitative and quantitative assessment of LV function can reliably be performed with cine sequences acquired after gadolinium injection, despite a significant decrease in the CNR and the overall image quality.

  7. TrueFisp versus HASTE sequences in 3T cine MRI: Evaluation of image quality during phonation in patients with velopharyngeal insufficiency

    International Nuclear Information System (INIS)

    Kulinna-Cosentini, Christiane; Czerny, Christian; Weber, Michael; Baumann, Arnulf; Sinko, Klaus

    2016-01-01

    To evaluate the image quality of two fast dynamic magnetic resonance imaging (MRI) sequences: True fast imaging with steady state precession (TrueFisp) was compared with half-Fourier acquired single turbo-spin-echo (HASTE) sequence for the characterization of velopharyngeal insufficiency (VPI) in repaired cleft palate patients. Twenty-two patients (10 female and 12 male; mean age, 17.7 ± 10.6 years; range, 9-31) with suspected VPI underwent 3-T MRI using TrueFisp and HASTE sequences. Imaging was performed in the sagittal plane at rest and during phonation of ''ee'' and ''k'' to assess the velum, tongue, posterior pharyngeal wall and a potential VP closure. The results were analysed independently by one radiologist and one orthodontist. HASTE performed better than TrueFisp for all evaluated items, except the tongue evaluation by the orthodontist during phonation of ''k'' and ''ee''. A statistically significant difference in favour of HASTE was observed in assessing the velum at rest and during phonation of ''k'' and ''ee'', and also in assessing VP closure in both raters (p < 0.05). TrueFisp imaging was twice as fast as HASTE (0.36 vs. 0.75 s/image). Dynamic HASTE images were of superior quality to those obtained with TrueFisp, although TrueFisp imaging was twice as fast. (orig.)

  8. A Technique for Generating Volumetric Cine MRI (VC-MRI)

    Science.gov (United States)

    Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

    2016-01-01

    Purpose To develop a technique to generate on-board volumetric-cine MRI (VC-MRI) using patient prior images, motion modeling and on-board 2D-cine MRI. Methods One phase of a 4D-MRI acquired during patient simulation is used as patient prior images. 3 major respiratory deformation patterns of the patient are extracted from 4D-MRI based on principal-component-analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2D-cine MRI. The method was evaluated using both XCAT simulation of lung cancer patients and MRI data from four real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using Volume-Percent-Difference(VPD), Center-of-Mass-Shift(COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest(ROI) selection, patient breathing pattern change and noise on the estimation accuracy were also evaluated. Results Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was on average 8.43±1.52% and the COMS was on average 0.93±0.58mm across all time-steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against noise levels up to SNR=20. For patient data, average tracking errors were less than 2 mm in all directions for all patients. Conclusions Preliminary studies demonstrated the

  9. Cine MRI of the thorax in patients with pectus excavatum

    International Nuclear Information System (INIS)

    Herrmann, K.A.; Zech, C.J.; Schoenberg, S.O.; Reiser, M.F.; Strauss, T.; Hatz, R.

    2006-01-01

    Morphologic and dynamic assessment of respiratory chest kinetics was performed in patients with pectus excavatum deformity (PE) using dynamic MRI: cine MRI. Seven consecutive patients with PE (aged 20.3 years±4.0) and ten healthy volunteers of comparable age underwent real-time cine MRI of the chest during breathing on a 1.5 T MR scanner (Magnetom Sonata, Siemens Medical Systems, Erlangen, Germany) using a standard phased array body coil and a half-Fourier single-shot turbo spin echo sequence (HASTE) for dynamic imaging. During deep inspiration and expiration, single-shot sequences were performed in one slice level over 20 s at a frequency of 1 image/s covering the entire thoracic cage in three orientations. Morphology and chest kinetics in patients with PE were analyzed and compared with normal values, and typical patterns of chest kinetics were noted. Three different types of chest morphology in PE were identified: (1) the generally flattened thoracic cage, (2) the ''tilted'' sternum, and (3) the focally deepened sternum. Three patterns of motion correspond to these morphological types: (1) elevation of the sternum and the anterior thoracic wall, (2) angulated elevation of the parasternal rib cage with persistent deepening of the sternum resembling a ''wing beat'' movement, and (3) increased diaphragmatic movements with limited chest wall dynamics. Cine MRI is an adequate radiation-free diagnostic modality for the dynamic imaging of both chest morphology and chest wall kinetics in patients with PE. The pectus severity index can easily be determined and three typical movement patterns of chest wall kinetics identified. (orig.) [de

  10. TU-G-BRD-08: In-Vivo EPID Dosimetry: Quantifying the Detectability of Four Classes of Errors

    Energy Technology Data Exchange (ETDEWEB)

    Ford, E; Phillips, M; Bojechko, C [University of Washington, Seattle, WA (United States)

    2015-06-15

    Purpose: EPID dosimetry is an emerging method for treatment verification and QA. Given that the in-vivo EPID technique is in clinical use at some centers, we investigate the sensitivity and specificity for detecting different classes of errors. We assess the impact of these errors using dose volume histogram endpoints. Though data exist for EPID dosimetry performed pre-treatment, this is the first study quantifying its effectiveness when used during patient treatment (in-vivo). Methods: We analyzed 17 patients; EPID images of the exit dose were acquired and used to reconstruct the planar dose at isocenter. This dose was compared to the TPS dose using a 3%/3mm gamma criteria. To simulate errors, modifications were made to treatment plans using four possible classes of error: 1) patient misalignment, 2) changes in patient body habitus, 3) machine output changes and 4) MLC misalignments. Each error was applied with varying magnitudes. To assess the detectability of the error, the area under a ROC curve (AUC) was analyzed. The AUC was compared to changes in D99 of the PTV introduced by the simulated error. Results: For systematic changes in the MLC leaves, changes in the machine output and patient habitus, the AUC varied from 0.78–0.97 scaling with the magnitude of the error. The optimal gamma threshold as determined by the ROC curve varied between 84–92%. There was little diagnostic power in detecting random MLC leaf errors and patient shifts (AUC 0.52–0.74). Some errors with weak detectability had large changes in D99. Conclusion: These data demonstrate the ability of EPID-based in-vivo dosimetry in detecting variations in patient habitus and errors related to machine parameters such as systematic MLC misalignments and machine output changes. There was no correlation found between the detectability of the error using the gamma pass rate, ROC analysis and the impact on the dose volume histogram. Funded by grant R18HS022244 from AHRQ.

  11. Quality control beam of radiation through imaging system using a flat panel (ILD); Control de calidad de haz de radiacion mediante un sistema de imagen de panel plano (EPID)

    Energy Technology Data Exchange (ETDEWEB)

    Benitez Serrano, J. A.; Gomez Barrado, A.; Sanchez-Reyes, A.

    2013-07-01

    The daily quality checks of the accelerator include, among others, checks of the daily calibration, symmetry and uniformity of the radiation beam. Usually verification systems daily are used for this purpose, which employ arrays of detectors of solid-state or ionization chambers. This paper intends to carry out the control of quality through the irradiation of a number of fields in the portal imaging system and its subsequent analysis in software's own creation, as well as the comparison of results with the daily verification system. (Author)

  12. Accelerated cardiac cine MRI using locally low rank and finite difference constraints.

    Science.gov (United States)

    Miao, Xin; Lingala, Sajan Goud; Guo, Yi; Jao, Terrence; Usman, Muhammad; Prieto, Claudia; Nayak, Krishna S

    2016-07-01

    To evaluate the potential value of combining multiple constraints for highly accelerated cardiac cine MRI. A locally low rank (LLR) constraint and a temporal finite difference (FD) constraint were combined to reconstruct cardiac cine data from highly undersampled measurements. Retrospectively undersampled 2D Cartesian reconstructions were quantitatively evaluated against fully-sampled data using normalized root mean square error, structural similarity index (SSIM) and high frequency error norm (HFEN). This method was also applied to 2D golden-angle radial real-time imaging to facilitate single breath-hold whole-heart cine (12 short-axis slices, 9-13s single breath hold). Reconstruction was compared against state-of-the-art constrained reconstruction methods: LLR, FD, and k-t SLR. At 10 to 60 spokes/frame, LLR+FD better preserved fine structures and depicted myocardial motion with reduced spatio-temporal blurring in comparison to existing methods. LLR yielded higher SSIM ranking than FD; FD had higher HFEN ranking than LLR. LLR+FD combined the complimentary advantages of the two, and ranked the highest in all metrics for all retrospective undersampled cases. Single breath-hold multi-slice cardiac cine with prospective undersampling was enabled with in-plane spatio-temporal resolutions of 2×2mm(2) and 40ms. Highly accelerated cardiac cine is enabled by the combination of 2D undersampling and the synergistic use of LLR and FD constraints. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Accelerated high-frame-rate mouse heart cine-MRI using compressed sensing reconstruction.

    Science.gov (United States)

    Motaal, Abdallah G; Coolen, Bram F; Abdurrachim, Desiree; Castro, Rui M; Prompers, Jeanine J; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

    2013-04-01

    We introduce a new protocol to obtain very high-frame-rate cinematographic (Cine) MRI movies of the beating mouse heart within a reasonable measurement time. The method is based on a self-gated accelerated fast low-angle shot (FLASH) acquisition and compressed sensing reconstruction. Key to our approach is that we exploit the stochastic nature of the retrospective triggering acquisition scheme to produce an undersampled and random k-t space filling that allows for compressed sensing reconstruction and acceleration. As a standard, a self-gated FLASH sequence with a total acquisition time of 10 min was used to produce single-slice Cine movies of seven mouse hearts with 90 frames per cardiac cycle. Two times (2×) and three times (3×) k-t space undersampled Cine movies were produced from 2.5- and 1.5-min data acquisitions, respectively. The accelerated 90-frame Cine movies of mouse hearts were successfully reconstructed with a compressed sensing algorithm. The movies had high image quality and the undersampling artifacts were effectively removed. Left ventricular functional parameters, i.e. end-systolic and end-diastolic lumen surface areas and early-to-late filling rate ratio as a parameter to evaluate diastolic function, derived from the standard and accelerated Cine movies, were nearly identical. Copyright © 2012 John Wiley & Sons, Ltd.

  14. Suitability of markerless EPID tracking for tumor position verification in gated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Serpa, Marco [Institute for Research and Development on Advanced Radiation Technologies (radART), Paracelsus Medical University, 5020 Salzburg (Austria); University Clinic for Radiotherapy and Radio-Oncology, Landeskrankenhaus Salzburg, Paracelsus Medical University Clinics, 5020 Salzburg (Austria); Department of Physics and Astronomy, University of Canterbury, Christchurch 8140 (New Zealand); Baier, Kurt; Guckenberger, Matthias [Department of Radiation Oncology, University of Wuerzburg, D-97080 Wuerzburg (Germany); Cremers, Florian [Department of Radiation Oncology, University Medical Center Hamburg Eppendorf, D-20246 Hamburg (Germany); Meyer, Juergen, E-mail: juergen@uw.edu [Department of Radiation Oncology, University of Washington, Seattle, Washington 98195 (United States)

    2014-03-15

    Purpose: To maximize the benefits of respiratory gated radiotherapy (RGRT) of lung tumors real-time verification of the tumor position is required. This work investigates the feasibility of markerless tracking of lung tumors during beam-on time in electronic portal imaging device (EPID) images of the MV therapeutic beam. Methods: EPID movies were acquired at ∼2 fps for seven lung cancer patients with tumor peak-to-peak motion ranges between 7.8 and 17.9 mm (mean: 13.7 mm) undergoing stereotactic body radiotherapy. The external breathing motion of the abdomen was synchronously measured. Both datasets were retrospectively analyzed inPortalTrack, an in-house developed tracking software. The authors define a three-step procedure to run the simulations: (1) gating window definition, (2) gated-beam delivery simulation, and (3) tumor tracking. First, an amplitude threshold level was set on the external signal, defining the onset of beam-on/-off signals. This information was then mapped onto a sequence of EPID images to generate stamps of beam-on/-hold periods throughout the EPID movies in PortalTrack, by obscuring the frames corresponding to beam-off times. Last, tumor motion in the superior-inferior direction was determined on portal images by the tracking algorithm during beam-on time. The residual motion inside the gating window as well as target coverage (TC) and the marginal target displacement (MTD) were used as measures to quantify tumor position variability. Results: Tumor position monitoring and estimation from beam's-eye-view images during RGRT was possible in 67% of the analyzed beams. For a reference gating window of 5 mm, deviations ranging from 2% to 86% (35% on average) were recorded between the reference and measured residual motion. TC (range: 62%–93%; mean: 77%) losses were correlated with false positives incidence rates resulting mostly from intra-/inter-beam baseline drifts, as well as sudden cycle-to-cycle fluctuations in exhale positions

  15. Assessment of small bowel motility in patients with chronic intestinal pseudo-obstruction using cine-MRI.

    Science.gov (United States)

    Ohkubo, Hidenori; Kessoku, Takaomi; Fuyuki, Akiko; Iida, Hiroshi; Inamori, Masahiko; Fujii, Tetsuro; Kawamura, Harunobu; Hata, Yasuo; Manabe, Noriaki; Chiba, Toshimi; Kwee, Thomas C; Haruma, Ken; Matsuhashi, Nobuyuki; Nakajima, Atsushi; Takahara, Taro

    2013-07-01

    Chronic intestinal pseudo-obstruction (CIPO) is a rare, serious motility disorder, with life-threatening complications over time. However, lack of an established, non-invasive diagnostic method has caused delays in the diagnosis of this intractable disease. Cine-magnetic resonance imaging (MRI) is an emerging technique, with a potential to evaluate the motility of the entire bowel. We compared small bowel motility in healthy volunteers, patients with irritable bowel syndrome (IBS), and those with CIPO, using cine-MRI, and evaluated the usefulness of cine-MRI as a novel diagnostic method for CIPO. Twelve healthy volunteers, IBS patients, and CIPO patients prospectively underwent cine-MRI at 1.5 T. Luminal diameter, contraction ratio, and contraction cycle were measured and compared between the groups. Cine-MRI provided sufficient dynamic images to assess the motility of the entire small bowel. Luminal diameter (mean±s.d.) in CIPO patients was significantly higher than that in healthy volunteers and IBS patients (43.4±14.1, 11.1±1.5, and 10.9±1.9 mm, respectively), and contraction ratio was significantly lower in CIPO patients than that in healthy volunteers and IBS patients (17.1±11.0%, 73.0±9.3%, and 74.6±9.4%, respectively). No significant differences were observed in the contraction cycle. This study is the first to assess the clinical utility of cine-MRI in CIPO patients. Cine-MRI clearly detected contractility impairments in CIPO patients. Cine-MRI is noninvasive, radiation-free, and can directly evaluate the entire small bowel peristalsis, and can detect the affected loops at a glance; therefore, it might be extremely useful for the diagnosis and follow-up of CIPO patients in clinical practice.

  16. Online 3D EPID-based dose verification: Proof of concept

    International Nuclear Information System (INIS)

    Spreeuw, Hanno; Rozendaal, Roel; Olaciregui-Ruiz, Igor; González, Patrick; Mans, Anton; Mijnheer, Ben; Herk, Marcel van

    2016-01-01

    Purpose: Delivery errors during radiotherapy may lead to medical harm and reduced life expectancy for patients. Such serious incidents can be avoided by performing dose verification online, i.e., while the patient is being irradiated, creating the possibility of halting the linac in case of a large overdosage or underdosage. The offline EPID-based 3D in vivo dosimetry system clinically employed at our institute is in principle suited for online treatment verification, provided the system is able to complete 3D dose reconstruction and verification within 420 ms, the present acquisition time of a single EPID frame. It is the aim of this study to show that our EPID-based dosimetry system can be made fast enough to achieve online 3D in vivo dose verification. Methods: The current dose verification system was sped up in two ways. First, a new software package was developed to perform all computations that are not dependent on portal image acquisition separately, thus removing the need for doing these calculations in real time. Second, the 3D dose reconstruction algorithm was sped up via a new, multithreaded implementation. Dose verification was implemented by comparing planned with reconstructed 3D dose distributions delivered to two regions in a patient: the target volume and the nontarget volume receiving at least 10 cGy. In both volumes, the mean dose is compared, while in the nontarget volume, the near-maximum dose (D2) is compared as well. The real-time dosimetry system was tested by irradiating an anthropomorphic phantom with three VMAT plans: a 6 MV head-and-neck treatment plan, a 10 MV rectum treatment plan, and a 10 MV prostate treatment plan. In all plans, two types of serious delivery errors were introduced. The functionality of automatically halting the linac was also implemented and tested. Results: The precomputation time per treatment was ∼180 s/treatment arc, depending on gantry angle resolution. The complete processing of a single portal frame

  17. Analysis of flow dynamics of main pulmonary artery by cine phase contrast MR angiography

    International Nuclear Information System (INIS)

    Honda, Norinari; Machida, Kikuo; Mamiya, Toshio

    1996-01-01

    Nineteen studies of cine phase contrast MR angiography (PCMRA) of main pulmonary artery (MPA) entered the study. Cine PCMRA was obtained by a 1.5T MR imager with a gradient echo sequence coupled with velocity encoding bipolar pulses. Retrospective EKG gating was used. Mean velocity, maximum velocity, and maximum flow rate of MPA were 6.2 to 28 cm/s (mean/SD 13/5.1, n=18), 61 to 148 cm/s (mean/SD 102/30, n=13), and 12,561 to 30,113 ml/min (mean/SD 18,730/5,464, n=18), respectively. Retrograde flow in the MPA was noted to begin at late-to mid-systole. Retrograde flow occurred first in the posterior part (15/19) or occurred from periphery (4/19). Thus hemodynamic parameters and velocity maps of MPA can be obtained by cine PCMRA. (author)

  18. 2D EPID dose calibration for pretreatment quality control of conformal and IMRT fields: A simple and fast convolution approach.

    Science.gov (United States)

    Camilleri, Jérémy; Mazurier, Jocelyne; Franck, Denis; Dudouet, Philippe; Latorzeff, Igor; Franceries, Xavier

    2016-01-01

    This work presents an original algorithm that converts the signal of an electronic portal imaging device (EPID) into absorbed dose in water at the depth of maximum. The model includes a first image pre-processing step that accounts for the non-uniformity of the detector response but also for the perturbation of the signal due to backscatter radiation. Secondly, the image is converted into absorbed dose to water through a linear conversion function associated with a dose redistribution kernel. These two computation parameters were modelled by correlating the on-axis EPID signal with absorbed dose measurements obtained on square fields by using an ionization chamber placed in water at the depth of maximum dose. The accuracy of the algorithm was assessed by comparing the dose determined from the EPID signal with the dose derived by the treatment planning system (TPS) using the ϒ-index. These comparisons were performed on 8 conformal radiotherapy treatment fields (3DCRT) and 18 modulated fields (IMRT). For a dose difference and a distance-to-agreement set to 3% of the maximum dose and 2 mm respectively, the mean percentage of points with a ϒ-value less than or equal to 1 was 99.8% ± 0.1% for 3DCRT fields and 96.8% ± 2.7% for IMRT fields. Moreover, the mean gamma values were always less than 0.5 whatever the treatment technique. These results confirm that our algorithm is an accurate and suitable tool for clinical use in a context of IMRT quality assurance programmes. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  19. Volumetric Arterial Wall Shear Stress Calculation Based on Cine Phase Contrast MRI

    NARCIS (Netherlands)

    Potters, Wouter V.; van Ooij, Pim; Marquering, Henk; VanBavel, Ed; Nederveen, Aart J.

    2015-01-01

    PurposeTo assess the accuracy and precision of a volumetric wall shear stress (WSS) calculation method applied to cine phase contrast magnetic resonance imaging (PC-MRI) data. Materials and MethodsVolumetric WSS vectors were calculated in software phantoms. WSS algorithm parameters were optimized

  20. Value of Cine-MRI sequences before and after injection in the diagnosis of acute myocarditis.

    Science.gov (United States)

    Zidi, Asma; Zairi, Ihsen; Mzoughi, Khadija; Zakhama, Lilia; Kamoun, Ikram; Ben Halima, Afef; Ridene, Imen

    2016-11-01

    Cardiovascular magnetic resonance (CMR) has become the examination of choice in case of suspicion of acute myocarditis. Late gadolinium enhancement (LGE) imaging is very important to establish this diagnosis. Cine MRI sequences are useful for the study of the myocardial contractility.   The purpose is to estimate the value of cine MRI sequences before and after injection for the diagnosis of acute myocarditis compared with late gadolinium enhanced sequences. We prospectively included 40 patients having a high suspicion of acute myocarditis and examined using a 1.5 Tesla CMR. Cine MRI sequences before and after injection were performed. The protocol also include  T2-weighted  short- tau-inversion-recovery (STIR T2) fast spin echo MRI and LGE imaging eight minutes after injection with visual adjustment of inversion time. Delayed enhancement was found among 23 patients. Fifteen patients (65 %) presented a spontaneous hyper signal detected visually on Cine MRI sequences before injection and 11 patients (48 %) on STIR T2. The hyper signal on Cine MRI sequences after injection of gadolinium was the same topography that the late raising at 23 patients. In addition, we highlighted a significant difference between this hyper signal before injection and the left ventricle ejection fraction (p=0.022) as well as with the telesystolic volume of the left ventricle (LV) indexed by the body mass (p=0.039). Our study suggests that Cine MRI sequences after injection are of equal performance in the diagnosis of acute myocarditis as the LGE sequences and its contibution is important when we want to shorten the examination or when inversion time isn't optimal.

  1. SU-E-T-139: Automated Daily EPID Exit Dose Analysis Uncovers Treatment Variations

    Energy Technology Data Exchange (ETDEWEB)

    Olch, A [University of Southern California, Los Angeles, CA (United States)

    2015-06-15

    Purpose: To evaluate a fully automated EPID exit dose system for its ability to detect daily treatment deviations including patient setup, delivery, and anatomy changes. Methods: PerFRACTION (Sun Nuclear Corporation) software is a system that uses integrated EPID images taken during patient treatment and automatically pulled from the Aria database and analyzed based on user-defined comparisons. This was used to monitor 20 plans consisting of a total of 859 fields for 18 patients, for a total of 251 fractions. Nine VMAT, 5 IMRT, and 6 3D plans were monitored. The Gamma analysis was performed for each field within a plan, comparing the first fraction against each of the other fractions in each treatment course. A 2% dose difference, 1 mm distance-to-agreement, and 10% dose threshold was used. These tight tolerances were chosen to achieve a high sensitivity to treatment variations. The field passed if 93% of the pixels had a Gamma of 1 or less. Results: Twenty-nine percent of the fields failed. The average plan passing rate was 92.5%.The average 3D plan passing rate was less than for VMAT or IMRT, 84%, vs. an average of 96.2%. When fields failed, an investigation revealed changes in patient anatomy or setup variations, often also leading to variations of transmission through immobilization devices. Conclusion: PerFRACTION is a fully automated system for determining daily changes in dose transmission through the patient that requires no effort other than for the imager panel to be deployed during treatment. A surprising number of fields failed the analysis and can be attributed to important treatment variations that would otherwise not be appreciated. Further study of inter-fraction treatment variations is possible and warranted. Sun Nuclear Corporation provided a license to the software described.

  2. Functional MRI of the patellofemoral joint: comparison of ultrafast MRI, motion-triggered cine MRI and static MRI

    International Nuclear Information System (INIS)

    Muhle, C.; Brossmann, J.; Melchert, U.H.; Schroeder, C.; Boer, R. de; Spielmann, R.P.; Heller, M.

    1995-01-01

    To evaluate the feasibility and usefulness of ultrafast MRI (u), patellar tracking from 30 of flexion to knee extension (0 ) was analysed and compared with motion-triggered cine MRI (m) and a static MRI technique (s). The different imaging methods were compared in respect of the patellofemoral relationship, the examination time and image quality. Eight healthy subjects and four patients (in total 18 joints) with patellar subluxation or luxation were examined. Significant differences between the static MRI series without quadriceps contraction and the functional MRI studies (motion-triggered cine MRI and ultrafast MRI) were found for the patellar tilt angle. In the dynamic joint studies there was no statistical difference of the regression coefficients between the motion-triggered cine MRI studies and the ultrafast MRI studies. The findings of the functional MRI studies compared with the static MRI images were significantly different for the lateralisation of the patella, expressed by the lateral patellar displacement and bisect offset. No significant differences in patellar lateralisation were found between motion-triggered cine MRI and ultrafast MRI. Ultrafast MRI was superior to motion-triggered cine MRI in terms of the reduction in imaging time and improvement of the image quality. (orig.)

  3. Functional MRI of the patellofemoral joint: comparison of ultrafast MRI, motion-triggered cine MRI and static MRI

    Energy Technology Data Exchange (ETDEWEB)

    Muhle, C. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany); Brossmann, J. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany); Melchert, U.H. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany); Schroeder, C. [Radiologische Abt., Universitaets-Kinderklinik, Christian-Albrechts-Universitaet, Kiel (Germany); Boer, R. de [Philips Medical Systems, Best (Netherlands); Spielmann, R.P. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany); Heller, M. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany)

    1995-12-31

    To evaluate the feasibility and usefulness of ultrafast MRI (u), patellar tracking from 30 of flexion to knee extension (0 ) was analysed and compared with motion-triggered cine MRI (m) and a static MRI technique (s). The different imaging methods were compared in respect of the patellofemoral relationship, the examination time and image quality. Eight healthy subjects and four patients (in total 18 joints) with patellar subluxation or luxation were examined. Significant differences between the static MRI series without quadriceps contraction and the functional MRI studies (motion-triggered cine MRI and ultrafast MRI) were found for the patellar tilt angle. In the dynamic joint studies there was no statistical difference of the regression coefficients between the motion-triggered cine MRI studies and the ultrafast MRI studies. The findings of the functional MRI studies compared with the static MRI images were significantly different for the lateralisation of the patella, expressed by the lateral patellar displacement and bisect offset. No significant differences in patellar lateralisation were found between motion-triggered cine MRI and ultrafast MRI. Ultrafast MRI was superior to motion-triggered cine MRI in terms of the reduction in imaging time and improvement of the image quality. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2016-12-15

    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.

  5. MO-FG-202-07: Real-Time EPID-Based Detection Metric For VMAT Delivery Errors

    International Nuclear Information System (INIS)

    Passarge, M; Fix, M K; Manser, P; Stampanoni, M F M; Siebers, J V

    2016-01-01

    Purpose: To create and test an accurate EPID-frame-based VMAT QA metric to detect gross dose errors in real-time and to provide information about the source of error. Methods: A Swiss cheese model was created for an EPID-based real-time QA process. The system compares a treatmentplan- based reference set of EPID images with images acquired over each 2° gantry angle interval. The metric utilizes a sequence of independent consecutively executed error detection Methods: a masking technique that verifies infield radiation delivery and ensures no out-of-field radiation; output normalization checks at two different stages; global image alignment to quantify rotation, scaling and translation; standard gamma evaluation (3%, 3 mm) and pixel intensity deviation checks including and excluding high dose gradient regions. Tolerances for each test were determined. For algorithm testing, twelve different types of errors were selected to modify the original plan. Corresponding predictions for each test case were generated, which included measurement-based noise. Each test case was run multiple times (with different noise per run) to assess the ability to detect introduced errors. Results: Averaged over five test runs, 99.1% of all plan variations that resulted in patient dose errors were detected within 2° and 100% within 4° (∼1% of patient dose delivery). Including cases that led to slightly modified but clinically equivalent plans, 91.5% were detected by the system within 2°. Based on the type of method that detected the error, determination of error sources was achieved. Conclusion: An EPID-based during-treatment error detection system for VMAT deliveries was successfully designed and tested. The system utilizes a sequence of methods to identify and prevent gross treatment delivery errors. The system was inspected for robustness with realistic noise variations, demonstrating that it has the potential to detect a large majority of errors in real-time and indicate the error

  6. MO-FG-202-07: Real-Time EPID-Based Detection Metric For VMAT Delivery Errors

    Energy Technology Data Exchange (ETDEWEB)

    Passarge, M; Fix, M K; Manser, P [Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern (Switzerland); Stampanoni, M F M [Institute for Biomedical Engineering, ETH Zurich, and PSI, Villigen (Switzerland); Siebers, J V [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)

    2016-06-15

    Purpose: To create and test an accurate EPID-frame-based VMAT QA metric to detect gross dose errors in real-time and to provide information about the source of error. Methods: A Swiss cheese model was created for an EPID-based real-time QA process. The system compares a treatmentplan- based reference set of EPID images with images acquired over each 2° gantry angle interval. The metric utilizes a sequence of independent consecutively executed error detection Methods: a masking technique that verifies infield radiation delivery and ensures no out-of-field radiation; output normalization checks at two different stages; global image alignment to quantify rotation, scaling and translation; standard gamma evaluation (3%, 3 mm) and pixel intensity deviation checks including and excluding high dose gradient regions. Tolerances for each test were determined. For algorithm testing, twelve different types of errors were selected to modify the original plan. Corresponding predictions for each test case were generated, which included measurement-based noise. Each test case was run multiple times (with different noise per run) to assess the ability to detect introduced errors. Results: Averaged over five test runs, 99.1% of all plan variations that resulted in patient dose errors were detected within 2° and 100% within 4° (∼1% of patient dose delivery). Including cases that led to slightly modified but clinically equivalent plans, 91.5% were detected by the system within 2°. Based on the type of method that detected the error, determination of error sources was achieved. Conclusion: An EPID-based during-treatment error detection system for VMAT deliveries was successfully designed and tested. The system utilizes a sequence of methods to identify and prevent gross treatment delivery errors. The system was inspected for robustness with realistic noise variations, demonstrating that it has the potential to detect a large majority of errors in real-time and indicate the error

  7. Motion compensated cine CMR of the fetal heart using radial undersampling and compressed sensing.

    Science.gov (United States)

    Roy, Christopher W; Seed, Mike; Kingdom, John C; Macgowan, Christopher K

    2017-03-20

    To develop and evaluate a reconstruction framework for high resolution time-resolved CMR of the fetal heart in the presence of motion. Data were acquired using a golden angle radial trajectory in seven fetal subjects and reconstructed as real-time images to detect fetal movement. Data acquired during through-plane motion were discarded whereas in-plane motion was corrected. A fetal cardiac gating signal was extracted to sort the corrected data by cardiac phase, allowing reconstruction of cine images. The quality of motion corrected images and the effect of data undersampling were quantified using separate expressions for spatial blur and image error. Motion corrected reordered cine reconstructions (127 slices) showed improved image quality relative to both uncorrected cines and corresponding real-time images across a range of root-mean-squared (RMS) displacements (0.3-3.7 mm) and fetal heart rates (119-176 bpm). The relative spatial blur between cines with and without motion correction increased with in-plane RMS displacement leading to an effective decrease in the effective spatial resolution for images without motion correction. Image error between undersampled and reference images was less than 10% for reconstructions using 750 or more spokes, yielding a minimum acceptable scan time of approximately 4 s/slice during quiescent through plane motion. By rejecting data corrupted by through-plane motion, and correcting data corrupted by in-plane translation, the proposed reconstruction framework accounts for common sources of motion artifact (gross fetal movement, maternal respiration, fetal cardiac contraction) to produce high quality images of the fetal heart.

  8. TH-A-BRF-04: Intra-Fraction Motion Characterization for Early Stage Rectal Cancer Using Cine-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kleijnen, J; Asselen, B; Burbach, M; Intven, M; Reerink, O; Philippens, M; Lagendijk, J; Raaymakers, B [University Medical Center Utrecht, Utrecht (Netherlands)

    2014-06-15

    Purpose: To investigate the intra-fraction motion in patients with early stage rectal cancer using cine-MRI. Methods: Sixteen patient diagnosed with early stage rectal cancer underwent 1.5 T MR imaging prior to each treatment fraction of their short course radiotherapy (n=76). During each scan session, three 2D sagittal cine-MRIs were performed: at the beginning (Start), after 9:30 minutes (Mid), and after 18 minutes (End). Each cine-MRI has a duration of one minute at 2Hz temporal resolution, resulting in a total of 3:48 hours of cine-MRI. Additionally, standard T2-weighted (T2w) imaging was performed. Clinical target volume (CTV) an tumor (GTV) were delineated on the T2w scan and transferred to the first time-point of each cine-MRI scan. Within each cine-MRI, the first frame was registered to the remaining frames of the scan, using a non-rigid B-spline registration. To investigate potential drifts, a similar registration was performed between the first frame of the Start and End scans.To evaluate the motion, the distances by which the edge pixels of the delineations move in anterior-posterior (AP) and cranial-caudal (CC) direction, were determined using the deformation field of the registrations. The distance which incorporated 95% of these edge pixels (dist95%) was determined within each cine-MRI, and between Start- End scans, respectively. Results: Within a cine-MRI, we observed an average dist95% for the CTV of 1.3mm/1.5mm (SD=0.7mm/0.6mm) and for the GTV of 1.2mm/1.5mm (SD=0.8mm/0.9mm), in respectively AP/CC. For the CTV motion between the Start and End scan, an average dist95% of 5.5mm/5.3mm (SD=3.1mm/2.5mm) was found, in respectively AP/CC. For the GTV motion, an average dist95% of 3.6mm/3.9mm (SD=2.2mm/2.5mm) was found in AP/CC, respectively. Conclusion: Although intra-fraction motion within a one minute cine-MRI is limited, substantial intra-fraction motion was observed within the 18 minute time period between the Start and End cine-MRI.

  9. TH-A-BRF-04: Intra-Fraction Motion Characterization for Early Stage Rectal Cancer Using Cine-MRI

    International Nuclear Information System (INIS)

    Kleijnen, J; Asselen, B; Burbach, M; Intven, M; Reerink, O; Philippens, M; Lagendijk, J; Raaymakers, B

    2014-01-01

    Purpose: To investigate the intra-fraction motion in patients with early stage rectal cancer using cine-MRI. Methods: Sixteen patient diagnosed with early stage rectal cancer underwent 1.5 T MR imaging prior to each treatment fraction of their short course radiotherapy (n=76). During each scan session, three 2D sagittal cine-MRIs were performed: at the beginning (Start), after 9:30 minutes (Mid), and after 18 minutes (End). Each cine-MRI has a duration of one minute at 2Hz temporal resolution, resulting in a total of 3:48 hours of cine-MRI. Additionally, standard T2-weighted (T2w) imaging was performed. Clinical target volume (CTV) an tumor (GTV) were delineated on the T2w scan and transferred to the first time-point of each cine-MRI scan. Within each cine-MRI, the first frame was registered to the remaining frames of the scan, using a non-rigid B-spline registration. To investigate potential drifts, a similar registration was performed between the first frame of the Start and End scans.To evaluate the motion, the distances by which the edge pixels of the delineations move in anterior-posterior (AP) and cranial-caudal (CC) direction, were determined using the deformation field of the registrations. The distance which incorporated 95% of these edge pixels (dist95%) was determined within each cine-MRI, and between Start- End scans, respectively. Results: Within a cine-MRI, we observed an average dist95% for the CTV of 1.3mm/1.5mm (SD=0.7mm/0.6mm) and for the GTV of 1.2mm/1.5mm (SD=0.8mm/0.9mm), in respectively AP/CC. For the CTV motion between the Start and End scan, an average dist95% of 5.5mm/5.3mm (SD=3.1mm/2.5mm) was found, in respectively AP/CC. For the GTV motion, an average dist95% of 3.6mm/3.9mm (SD=2.2mm/2.5mm) was found in AP/CC, respectively. Conclusion: Although intra-fraction motion within a one minute cine-MRI is limited, substantial intra-fraction motion was observed within the 18 minute time period between the Start and End cine-MRI

  10. Dynamic change in size of the lateral ventricle evaluated by cine MRI

    International Nuclear Information System (INIS)

    Abe, Toshi

    1990-01-01

    CSF pulsation suggests variation in the size of the cerebral ventricle during the cardiac cycle. CINE MRI, which is a useful technique for observation of the pulsatile CSF flow, demonstrates a dynamic change in size of the lateral ventricle. CINE MRI was performed on a 0.5 tesla MR imaging system (SMT-50, SHIMADZU). Sixteen different phased images during cardiac cycle were made by a gradient acho technique (STAGE: Short Tip Angle Gradient Echo, TE=14 msec, Flip Angle=30deg). From the measurement of the lateral ventricular areas of two different phases of CINE MRI during cadiac cycle, variation rate of cerebral ventricular area (VRCVA) was calculated. Twenty-five normal volunteers (14 younger adults aged 27-44 years, 11 older adults aged 56-73 years) and six cases of marked diffuse cerebral atrophy were studied. The results included: The mean VRCVA of younger adults was 14.4% (at right body of lateral ventricle) ∼ 30.0% (at left anterior horn of lateral ventricle). The mean VRCVA of younger adults is higher than the mean VRCVA of older adults. In the cases of marked diffuse cerebral atrophy, the mean VRCVA was very lower than the mean VRCVA of older adults. VRCVA of lateral ventricle calculated from CINE MRI seemed to have a good relationship to the brain elasticity. This noninvasive method would be used as an indication of the elastic response of the ventricles and the surrounding brain. (J.P.N.)

  11. Application of an EPID for fast daily dosimetric quality control of a fully computer-controlled treatment unit

    Energy Technology Data Exchange (ETDEWEB)

    Dirkx, M.L.P.; Kroonwijk, M.; De Boer, J.C.J.; Heijmen, B.J.M. [Nederlands Kanker Inst. `Antoni van Leeuwenhoekhuis`, Amsterdam (Netherlands)

    1995-12-01

    The MM50 Racetrack Microtron, suited for sophisticated three-dimensional computer-controlled conformal radiotherapy techniques, is a complex treatment unit in various respects. Therefore, for a number of gantry angles, daily quality control of the absolute output and the profiles of the scanned photon beams in mandatory. A fast method for these daily checks, based on dosimetric measurements with the Philips SRI-100 Electronic Portal Imaging Device, has been developed and tested. Open beams are checked for four different gantry angles; for gantry angle 0, a wedged field is checked as well. The fields are set up one after another under full computer control. Performing and analyzing the measurements takes about ten minutes. The applied EPID has favourable characteristics for dosimetric quality control measurements: absolute measurements reproduce within 0.5% (1 SD) and the reproducibility of a relative (2-D) fluence profile is 0.2% (1 SD). The day-to-day sensitivity stability over a period of a month is 0.6% (1 SD). EPID-signals are within 0.2% linear with the applied dose. The 2-D fluence profile of the 25 MV photon beam of the MM50 is very stable in time: during a period of one year, a maximum fluctuation of 2.6% was observed. Once, a deviation in the cGy/MU-value of 6% was detected. Only because of the performed morning quality control checks with the EPID, erroneous dose delivery to patients could be avoided; there is no interlock in the MM50-system that would have prevented patient treatment. Based on our experiences and on clinical requirements regarding the acceptability of deviations of beam characteristics, a protocol has been developed including action levels for additional investigations. Studies on the application of the SRI-100 for in vivo dosimetry on the MM50 have been started.

  12. New developments in EPID-based 3D dosimetry in The Netherlands Cancer Institute

    Science.gov (United States)

    Mijnheer, B.; Rozendaal, R.; Olaciregui-Ruiz, I.; González, P.; van Oers, R.; Mans, A.

    2017-05-01

    EPID-based offline 3D in vivo dosimetry is performed routinely in The Netherlands Cancer Institute for almost all RT treatments. The 3D dose distribution is reconstructed using the EPID primary dose in combination with a back-projection algorithm and compared with the planned dose distribution. Recently the method was adapted for real-time dose verification, performing 3D dose verification in less than 300 ms, which is faster than the current portal frame acquisition rate. In this way a possibility is created for halting the linac in case of large delivery errors. Furthermore, a new method for pre-treatment QA was developed in which the EPID primary dose behind a phantom or patient is predicted using the CT data of that phantom or patient in combination with in-air EPID measurements. This virtual EPID primary transit dose is then used to reconstruct the 3D dose distribution within the phantom or patient geometry using the same dose engine as applied offline. In order to assess the relevance of our clinically applied alert criteria, we investigated the sensitivity of our EPID-based 3D dose verification system to detect delivery errors in VMAT treatments. This was done through simulation by modifying patient treatment plans, as well as experimentally by performing EPID measurements during the irradiation of an Alderson phantom, both after deliberately introducing errors during VMAT delivery. In this presentation these new developments will be elucidated.

  13. Using an electronic portal imaging device for exit dose measurements in radiotherapy

    International Nuclear Information System (INIS)

    Ganowicz, M.; Wozniak, B.; Bekman, A.; Maniakowski, Z.

    2003-01-01

    To present a method of determining the exit dose with the use of an electronic portal imaging device (EPID). The device used was the Portal Vision LC250 (Varian). The EPID signals on the central beam axis have been related to the exit dose. The exit dose measurements were performed with the ionisation chamber in the slab phantom at the distance of dose maximum from the exit surface of the phantom. EPID reading was investigated as a function of field size, phantom thickness and source-detector distance. The relation between dose rate and the EPID reading is described with empirical functions applicable to the obtained data. The exit dose is calculated from the EPID reading as a product of the calibration factor and appropriate correction factors. The determination of the exit dose rate from the EPID signal requires the knowledge of many parameters and earlier determination of essential characteristics. (author)

  14. Cine vasco y euskera: debates de identidad

    OpenAIRE

    Fernández, Joxean

    2013-01-01

    INTRODUCCIÓN: LA ÓSMOSIS HISTORIA-CINE Los físicos suelen hablar de ósmosis para referirse al paso recíproco de dos líquidos de distinta densidad a través de una membrana semipermeable que los separa. Asimismo, en lenguaje literario, hablamos de ósmosis para definir simplemente influencias recíprocas. Nos permitimos utilizar aquí este término prestado de otras disciplinas científicas para tratar de obtener una imagen de las relaciones que el cine y la historia vienen manteniendo desde que aqu...

  15. Cine y estadística

    OpenAIRE

    Sorando, José M.

    2012-01-01

    Hay estadísticas de cualquier tema, también de cine. Algunas son tan chocantes como la que recoge la tabla 1, para fans de las películas de rambo. Es una simple estadística descriptiva que no va más allá de las frecuencias de tiroteos y decesos, de ella se desprende alguna conclusión, como la virulencia creciente de la serie; y alguna sospecha, como su posible relación con la abstinencia sexual… Claro que hay otras estadísticas de cine más respetables.

  16. Experimental study on quantitative evaluation of slow pulsatile flow of CSF with cine MRI

    International Nuclear Information System (INIS)

    Matsuda, Masao

    1991-01-01

    The present study was designed to evaluate the slow pulsatile flow of cerebrospinal fluid (CSF) quantitatively with cine MRI in phantom experiment for the clinical application. The flow phantom was constructed from a plastic tube with a narrow channel to represent the central aqueduct. The phantom was filled with water to represent the CSF. The second tube filled with stationary water was positioned beside the flow phantom and acted as a control for no-flow signal strength. The ratio of signal intensity in regions of interest for the flow phantom and the control was measured. Not only the actual velocity curve of the flowing water through the phantom but also the temporal profile of signal intensity showed two main peaks with other small peaks in one cycle. This suggested a close relationship between signal intensity of cine MRI and flow velocity. A significant correlation between the signal intensity ratio and the velocity was obtained on cine MRI pulse sequences. Cine MRI was thus found to have the ability to give quantitative information about slow pulsatile flow. The most suitable pulse sequence was fast imaging with steady state free precession pulse sequence at the flip angle between 50 and 90 degrees. This preliminary study suggests that the slow pulsatile flow of CSF passing along the aqueduct can be visualized and measured. Thus, the sequence proposed has a potential for the investigation of normal and disturbed CSF circulation and the mapping of the flow pattern in different pathological conditions. (N.K.)

  17. Tracheomalacia in adults with cystic fibrosis: determination of prevalence and severity with dynamic cine CT.

    LENUS (Irish Health Repository)

    McDermott, Shaunagh

    2012-02-01

    PURPOSE: To determine the prevalence and severity of tracheomalacia in adults with cystic fibrosis (CF) by using dynamic cine multidetector computed tomography (CT) and to correlate these findings with pulmonary function test (PFT) results and the severity of parenchymal lung disease. MATERIALS AND METHODS: In this institutional review board-approved HIPAA-compliant study, 40 patients with CF (22 men, 18 women; mean age, 28 years +\\/- 8 [standard deviation]; age range, 18-54 years) prospectively underwent PFTs, standard thin-section CT, and two dynamic cine multidetector CT acquisitions. Ten control subjects underwent dynamic cine multidetector CT. After standard thin-section CT was completed, dynamic cine multidetector CT was performed during a forced expiratory maneuver and during coughing. Dynamic cine multidetector CT images in nine patients were excluded. Maximal inspiratory, dynamic expiratory, and end-expiratory tracheal luminal areas were compared (Student t test) and correlated (Spearman rank) with PFT results and severity of parenchymal lung disease. RESULTS: Mean predicted forced expiratory volume in 1 second (FEV(1)) was 70.6% +\\/- 20.7, and mean Bhalla CT score was 41.8% +\\/- 13.6. In patients with CF, dynamic cine mean tracheal cross-sectional area reduction was 51.7% +\\/- 18.4 (range, 9%-89%) for forced expiratory maneuvers and 68.8% +\\/- 11.7 (range, 18%-88%) for coughing (P = .001). Tracheomalacia was demonstrated in 24 (69%) patients and no control subjects during forced expiratory maneuvers (P = .001) and in 10 (29%) patients and one (10%) control subject during coughing. For end-expiration images, mean tracheal luminal reduction was 16.1% +\\/- 14.0% (range, 0.0%-53.0%), with one patient demonstrating tracheal luminal reduction of more than 50%. There was no correlation between tracheal cross-sectional luminal reduction and either predicted FEV(1) or CT Bhalla score. CONCLUSION: Tracheomalacia depicted at dynamic cine multidetector CT is a

  18. Automated assessments of circumferential strain from cine CMR correlate with LVEF declines in cancer patients early after receipt of cardio-toxic chemotherapy.

    Science.gov (United States)

    Jolly, Marie-Pierre; Jordan, Jennifer H; Meléndez, Giselle C; McNeal, Gary R; D'Agostino, Ralph B; Hundley, W Gregory

    2017-08-02

    In patients with cancer receiving potentially cardio-toxic chemotherapy, measurements of left ventricular (LV) circumferential or longitudinal strain are often used clinically to identify myocardial dysfunction. Using a new software algorithm, we sought to determine in individuals receiving treatment for cancer the association between automated assessments of LV mean mid-wall circumferential strain and conventional measures of LV ejection fraction (EF) both obtained from cardiovascular magnetic resonance (CMR) cine balanced steady-state free-precession (bSSFP) white-blood acquisitions. Before and 3 months after initiating treatment with potentially cardio-toxic chemotherapy, 72 individuals (aged 54 ± 14 years with breast cancer [39%], lymphoma [49%], or sarcoma [12%]) underwent serial CMR cine bSSFP assessments of LV volumes and EF, and mean mid-wall circumferential strain determined from these same cine images as well as from additional tagged CMR images. On the cine images, assessments of strain were obtained using the newly developed deformation-based segmentation algorithm. Assessments of LV volumes/EF from the cine images and strain from tagged CMR were accomplished using commercially available software. All measures were analyzed in a blinded fashion independent of one another. Acceptable measures for the automated assessments of mean mid-wall circumferential strain from the cine images were obtained in 142 of 144 visits (98.6%) with an overall analysis time averaging 6:47 ± 1:06 min. The results from these automated measures averaged -18.8 ± 2.9 at baseline and -17.6 ± 3.1 at 3 months (p = 0.001). Left ventricular EF declined slightly from 65 ± 7% at baseline to 62 ± 7% at 3 months (p = 0.0002). The correlation between strain from cine imaging and LVEF was r = -0.61 (p cine and tagged derived assessments of strain was r = 0.23; p = 0.01. Automated measures of LV mean mid-wall circumferential strain can be obtained in 6

  19. Colon wall motility: comparison of novel quantitative semi-automatic measurements using cine MRI.

    Science.gov (United States)

    Hoad, C L; Menys, A; Garsed, K; Marciani, L; Hamy, V; Murray, K; Costigan, C; Atkinson, D; Major, G; Spiller, R C; Taylor, S A; Gowland, P A

    2016-03-01

    Recently, cine magnetic resonance imaging (MRI) has shown promise for visualizing movement of the colonic wall, although assessment of data has been subjective and observer dependent. This study aimed to develop an objective and semi-automatic imaging metric of ascending colonic wall movement, using image registration techniques. Cine balanced turbo field echo MRI images of ascending colonic motility were acquired over 2 min from 23 healthy volunteers (HVs) at baseline and following two different macrogol stimulus drinks (11 HVs drank 1 L and 12 HVs drank 2 L). Motility metrics derived from large scale geometric and small scale pixel movement parameters following image registration were developed using the post ingestion data and compared to observer grading of wall motion. Inter and intra-observer variability in the highest correlating metric was assessed using Bland-Altman analysis calculated from two separate observations on a subset of data. All the metrics tested showed significant correlation with the observer rating scores. Line analysis (LA) produced the highest correlation coefficient of 0.74 (95% CI: 0.55-0.86), p cine MRI registered data provides a quick, accurate and non-invasive method to detect wall motion within the ascending colon following a colonic stimulus in the form of a macrogol drink. © 2015 John Wiley & Sons Ltd.

  20. Moto-cine en Madrid – Barajas

    Directory of Open Access Journals (Sweden)

    Chueca Goitia, Fernando

    1959-05-01

    Full Text Available Madrid, después de Roma, ha sido la segunda capital de Europa que ha construido y puesto en funcionamiento un motocine, es decir, un cine para automóviles, con arreglo a los últimos adelantos que este tipo de espectáculos ha llegado a alcanzar.

  1. Dose patient verification during treatment using an amorphous silicon electronic portal imaging device in radiotherapy

    International Nuclear Information System (INIS)

    Berger, Lucie

    2006-01-01

    Today, amorphous silicon electronic portal imaging devices (aSi EPID) are currently used to check the accuracy of patient positioning. However, they are not use for dose reconstruction yet and more investigations are required to allow the use of an aSi EPID for routine dosimetric verification. The aim of this work is first to study the dosimetric characteristics of the EPID available at the Institut Curie and then, to check patient dose during treatment using these EPID. First, performance optimization of the Varian aS500 EPID system is studied. Then, a quality assurance system is set up in order to certify the image quality on a daily basis. An additional study on the dosimetric performance of the aS500 EPID is monitored to assess operational stability for dosimetry applications. Electronic portal imaging device is also a useful tool to improve IMRT quality control. The validation and the quality assurance of a portal dose image prediction system for IMRT pre-treatment quality control are performed. All dynamic IMRT fields are verified in clinical routine with the new method based on portal dosimetry. Finally, a new formalism for in vivo dosimetry using transit dose measured with EPID is developed and validated. The absolute dose measurement issue using aSi EPID is described and the midplane dose determination using in vivo dose measurements in combination with portal imaging is used with 3D-conformal-radiation therapy. (author) [fr

  2. High spatial and temporal resolution retrospective cine cardiovascular magnetic resonance from shortened free breathing real-time acquisitions.

    Science.gov (United States)

    Xue, Hui; Kellman, Peter; Larocca, Gina; Arai, Andrew E; Hansen, Michael S

    2013-11-14

    Cine cardiovascular magnetic resonance (CMR) is challenging in patients who cannot perform repeated breath holds. Real-time, free-breathing acquisition is an alternative, but image quality is typically inferior. There is a clinical need for techniques that achieve similar image quality to the segmented cine using a free breathing acquisition. Previously, high quality retrospectively gated cine images have been reconstructed from real-time acquisitions using parallel imaging and motion correction. These methods had limited clinical applicability due to lengthy acquisitions and volumetric measurements obtained with such methods have not previously been evaluated systematically. This study introduces a new retrospective reconstruction scheme for real-time cine imaging which aims to shorten the required acquisition. A real-time acquisition of 16-20s per acquired slice was inputted into a retrospective cine reconstruction algorithm, which employed non-rigid registration to remove respiratory motion and SPIRiT non-linear reconstruction with temporal regularization to fill in missing data. The algorithm was used to reconstruct cine loops with high spatial (1.3-1.8 × 1.8-2.1 mm²) and temporal resolution (retrospectively gated, 30 cardiac phases, temporal resolution 34.3 ± 9.1 ms). Validation was performed in 15 healthy volunteers using two different acquisition resolutions (256 × 144/192 × 128 matrix sizes). For each subject, 9 to 12 short axis and 3 long axis slices were imaged with both segmented and real-time acquisitions. The retrospectively reconstructed real-time cine images were compared to a traditional segmented breath-held acquisition in terms of image quality scores. Image quality scoring was performed by two experts using a scale between 1 and 5 (poor to good). For every subject, LAX and three SAX slices were selected and reviewed in the random order. The reviewers were blinded to the reconstruction approach and acquisition protocols and

  3. Identifying decreased peristalsis of abnormal small bowel segments in Crohn's disease using cine MR enterography: the frozen bowel sign.

    Science.gov (United States)

    Guglielmo, Flavius F; Mitchell, Donald G; O'Kane, Patrick L; Deshmukh, Sandeep P; Roth, Christopher G; Burach, Ilene; Burns, Aaron; Dulka, Susan; Parker, Laurence

    2015-06-01

    The purpose of this study was to evaluate whether affected bowel in Crohn's disease patients can be identified by observing decreased peristalsis (frozen bowel sign) using cine balanced steady-state free precession (cine BSSFP) images. 5 radiologists independently reviewed cine BSSFP sequences from randomized MR Enterography (MRE) exams for 30 normal and 30 Crohn's disease patients, graded overall small bowel peristalsis from slowest to fastest, and graded peristalsis for the most abnormal small bowel segment. Sensitivity and specificity of the frozen bowel sign for diagnosing Crohn's disease were calculated. T tests of the peristalsis difference between abnormal segments and overall small bowel were conducted. For 5 readers, the sensitivity and specificity of cine BSSFP of the frozen bowel sign for diagnosing Crohn's disease ranged from 70% to 100% and 87% to 100%, respectively. There were significant differences in peristalsis between abnormal small bowel segments and the overall small bowel for Crohn's patients, but not in the overall small bowel between normal-MRE patients and Crohn's disease patients. Abnormal Crohn's small bowel segments have significantly decreased peristalsis compared to normal small bowel, which can be identified using cine BSSFP sequences as the frozen bowel sign.

  4. Noninvasive investigation of exocrine pancreatic function: Feasibility of cine dynamic MRCP with a spatially selective inversion-recovery pulse.

    Science.gov (United States)

    Yasokawa, Kazuya; Ito, Katsuyoshi; Tamada, Tsutomu; Yamamoto, Akira; Hayashida, Minoru; Tanimoto, Daigo; Higaki, Atsushi; Noda, Yasufumi; Kido, Ayumu

    2015-11-01

    To investigate the feasibility of noncontrast-enhanced cine dynamic magnetic resonance cholangiopancreatography (MRCP) with a spatially selective inversion-recovery (IR) pulse for evaluating exocrine pancreatic function in comparison with the N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA) test as a pancreatic exocrine function test. Twenty subjects with or without chronic pancreatitis were included. MRCP with a spatially selective IR pulse was repeated every 15 seconds for 5 minutes to acquire a total of 20 images (cine-dynamic MRCP). The median and mean frequency of the observation (the number of times) and the moving distance (mean secretion grading scores) of pancreatic juice inflow on cine-dynamic MRCP were compared with a BT-PABA test. The urinary PABA excretion rate (%) had significant positive correlations with both the mean secretion grade (r = 0.66, P = 0.002) and frequency of secretory inflow (r = 0.62, P = 0.004) in cine dynamic MRCP. Both the mean frequency of observations of pancreatic secretory inflow (1.4 ± 1.6 times vs. 14.3 ± 4.2 times, P Cine dynamic MRCP with a spatially selective IR pulse may have potential for estimating the pancreatic exocrine function noninvasively as a substitute for the BT-PABA test. © 2015 Wiley Periodicals, Inc.

  5. Espectadores en 3D: ¿El futuro del cine?

    Directory of Open Access Journals (Sweden)

    Díaz Gandasegui, Vicente

    2011-04-01

    Full Text Available This paper analyses the reintroduction of 3D to the big screen, this time, due to the digital technology and the polarization of the image, the focal depth has become more credible and the interface, in spite of still being present, is more comfortable and effective. The spectacular images attract the spectator to the cinema and captivate them with technological visual development. Simultaneously, 3D is a useful tool to solve contemporary cinema problems with piracy and competition with other media. However, the big question that 3D has to solve is whether the new technology will join the large list of fiascos of the 70’s and 80’s, trying to transform the way of seeing the image, or if it will be a step closer to virtual reality and a cinema of immersion and total interaction.

    El presente artículo analiza la (reintroducción del 3D en nuestras pantallas de cine. Esta vez, gracias a la tecnología digital y a la polarización de la imagen, la profundidad de campo se hace mas creíble y la interfaz, a pesar de seguir presente, ha ganado en comodidad y efectividad. La espectacularidad de las imágenes es el mayor reclamo que hoy presenta el 3D para atraer al espectador a las salas de cine y fascinarle con el desarrollo tecnológico. Al mismo tiempo, el 3D es una herramienta útil para solucionar los problemas surgidos en la industria cinematográfica a raíz de la evolución de la pirateria y la cada vez más compleja competición con otros medios. La gran duda que plantea el 3D es si se sumará a la larga lista de fracasos de los años 70 y 80 por intentar transformar la forma de ver la imagen o supondrá un paso adelante en la pretensión por acercarnos a la realidad virtual y un cine de inmersión e interacción total.

  6. aSi EPIDs for the in-vivo dosimetry of static and dynamic beams

    Science.gov (United States)

    Piermattei, A.; Cilla, S.; Azario, L.; Greco, F.; Russo, M.; Grusio, M.; Orlandini, L.; Fidanzio, A.

    2015-10-01

    Portal imaging by amorphous silicon (aSi) photodiode is currently the most applied technology for in-vivo dosimetry (IVD) of static and dynamic radiotherapy beams. The strategy, adopted in this work to perform the IVD procedure by aSi EPID, is based on: in patient reconstruction of the isocenter dose and day to day comparison between 2D-portal images to verify the reproducibility of treatment delivery. About 20.000 tests have been carried out in this last 3 years in 8 radiotherapy centers using the SOFTDISO program. The IVD results show that: (i) the procedure can be implemented for linacs of different manufacturer, (ii) the IVD analysis can be obtained on a computer screen, in quasi real time (about 2 min after the treatment delivery) and (iii) once the causes of the discrepancies were eliminated, all the global IVD tests for single patient were within the acceptance criteria defined by: ±5% for the isocenter dose, and PγFisica Nucleare (INFN) and Università Cattolica del S.Cuore (UCSC).

  7. Compressed sensing real-time cine cardiovascular magnetic resonance: accurate assessment of left ventricular function in a single-breath-hold.

    Science.gov (United States)

    Kido, Tomoyuki; Kido, Teruhito; Nakamura, Masashi; Watanabe, Kouki; Schmidt, Michaela; Forman, Christoph; Mochizuki, Teruhito

    2016-08-24

    Cardiovascular cine magnetic resonance (CMR) accelerated by compressed sensing (CS) is used to assess left ventricular (LV) function. However, it is difficult for prospective CS cine CMR to capture the complete end-diastolic phase, which can lead to underestimation of the end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF), compared to retrospective standard cine CMR. This prospective study aimed to evaluate the diagnostic quality and accuracy of single-breath-hold full cardiac cycle CS cine CMR, acquired over two heart beats, to quantify LV volume in comparison to multi-breath-hold standard cine CMR. Eighty-one participants underwent standard segmented breath-hold cine and CS real-time cine CMR examinations to obtain a stack of eight contiguous short-axis images with same high spatial (1.7 × 1.7 mm(2)) and temporal resolution (41 ms). Two radiologists independently performed qualitative analysis of image quality (score, 1 [i.e., "nondiagnostic"] to 5 [i.e., "excellent"]) and quantitative analysis of the LV volume measurements. The total examination time was 113 ± 7 s for standard cine CMR and 24 ± 4 s for CS cine CMR (p cine image quality was slightly lower than standard cine (4.8 ± 0.5 for standard vs. 4.4 ± 0.5 for CS; p cine were above 4 (i.e., good). No significant differences existed between standard and CS cine MR for all quantitative LV measurements. The mean differences with 95 % confidence interval (CI), based on Bland-Altman analysis, were 1.3 mL (95 % CI, -14.6 - 17.2) for LV end-diastolic volume, 0.2 mL (95 % CI, -9.8 to10.3) for LV end-systolic volume, 1.1 mL (95 % CI, -10.5 to 12.7) for LV stroke volume, 1.0 g (95 % CI, -11.2 to 13.3) for LV mass, and 0.4 % (95 % CI, -4.8 - 5.6) for LV ejection fraction. The interobserver and intraobserver variability for CS cine MR ranged from -4.8 - 1.6 % and from -7.3 - 9.3 %, respectively, with slopes of the regressions ranging 0.88-1.0 and 0

  8. SU-E-T-62: A Preliminary Experience of Using EPID Transit Dosimetry for Monitoring Daily Dose Variations in Radiation Treatment Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Yao, R; Chisela, W [Columbus Regional Healthcare, Columbus, GA (United States)

    2015-06-15

    Purpose: To investigate the use of EPID transit dosimetry for monitoring daily dose variations in radiation treatment delivery. Methods: A patient with head and neck cancer treated using nine field IMRT beams was used in this study. The prescription was 45 Gy in 25 fractions. A KV CBCT was acquired before each treatment on a Varian NTX linear accelerator. Integrated images using MV EPID were acquired for each treatment beam. Planning CT images, treatment plan, and daily integrated images were imported into a commercial QA software Dosimetry Check (v4r4 Math Resolutions, LLC, Columbia, MD) to calculate 3D dose of the day assuming 25 fractions treatment. Planning CT images were deformed and registered to each daily CBCT using Varian SmartAdapt (v11.MR2). ROIs were then propagated from planning CT to daily CBCT. The correlation between maximum, average dose of ROIs and ROI volume, center of mass shift, Dice Similarity Coefficient (DSC) were investigated. Results: Not all parameters investigated showed strong correlations. For PTV and CTV, the average dose has inverse correlation with their volume change (correlation coefficient −0.52, −0.50, respectively) and DSC (−0.59, −0.59, respectively). The average dose of right parotid has correlation with its volume change (0.56). The maximum dose of spinal cord has correlation with the center of mass superior-inferior shift (0.52) and inverse correlation with the center of mass anterior-posterior shift (−0.73). Conclusion: Transit dosimetry using EPID images collected during treatment delivery offers great potential to monitor daily dose variations due to patient anatomy change, motion, and setup errors in radiation treatment delivery. It can provide a patient-specific QA tool valuable for adaptive radiation therapy. Further work is needed to validate the technique.

  9. Requirements and Solutions for Archiving Scientific Data at CINES

    Science.gov (United States)

    Coutin, Stephane

    Historically an high-performance computing datacenter, the “Centre Informatique National de l’Enseignement Supérieur” (CINES) has also a mission of long term digital preservation. By coupling those two areas, it became obvious that CINES had to understand and take into account the requirements of scientific communities regarding their data life cycle, and more specifically their archiving requirements. We will present those requirements and describe the platforms CINES proposes for each service class.

  10. Direct comparison of high‐temporal‐resolution CINE MRI with Doppler ultrasound for assessment of diastolic dysfunction in mice

    Science.gov (United States)

    Price, Anthony N.; Jackson, Laurence H.; Taylor, Valerie; David, Anna L.; Lythgoe, Mark F.; Stuckey, Daniel J.

    2017-01-01

    Diastolic dysfunction is a sensitive early indicator of heart failure and can provide additional data to conventional measures of systolic function. Transmitral Doppler ultrasound, which measures the one‐dimensional flow of blood through the mitral valve, is currently the preferred method for the measurement of diastolic function, but the measurement of the left ventricular volume changes using high‐temporal‐resolution cinematic magnetic resonance imaging (CINE MRI) is an alternative approach which is emerging as a potentially more robust and user‐independent technique. Here, we investigated the performance of high‐temporal‐resolution CINE MRI and compared it with ultrasound for the detection of diastolic dysfunction in a mouse model of myocardial infarction. An in‐house, high‐temporal‐resolution, retrospectively gated CINE sequence was developed with a temporal resolution of 1 ms. Diastolic function in mice was assessed using a custom‐made, open‐source reconstruction package. Early (E) and late (A) left ventricular filling phases were easily identifiable, and these measurements were compared directly with high‐frequency, pulsed‐wave, Doppler ultrasound measurements of mitral valve inflow. A repeatability study established that high‐temporal‐resolution CINE MRI and Doppler ultrasound showed comparable accuracy when measuring E/A in normal control mice. However, when applied in a mouse model of myocardial infarction, high‐temporal‐resolution CINE MRI indicated diastolic heart failure (E/A = 0.94 ± 0.11), whereas ultrasound falsely detected normal cardiac function (E/A = 1.21 ± 0.11). The addition of high‐temporal‐resolution CINE MRI to preclinical imaging studies enhances the library of sequences available to cardiac researchers and potentially identifies diastolic heart failure early in disease progression. PMID:28643891

  11. Direct comparison of high-temporal-resolution CINE MRI with Doppler ultrasound for assessment of diastolic dysfunction in mice.

    Science.gov (United States)

    Roberts, Thomas A; Price, Anthony N; Jackson, Laurence H; Taylor, Valerie; David, Anna L; Lythgoe, Mark F; Stuckey, Daniel J

    2017-10-01

    Diastolic dysfunction is a sensitive early indicator of heart failure and can provide additional data to conventional measures of systolic function. Transmitral Doppler ultrasound, which measures the one-dimensional flow of blood through the mitral valve, is currently the preferred method for the measurement of diastolic function, but the measurement of the left ventricular volume changes using high-temporal-resolution cinematic magnetic resonance imaging (CINE MRI) is an alternative approach which is emerging as a potentially more robust and user-independent technique. Here, we investigated the performance of high-temporal-resolution CINE MRI and compared it with ultrasound for the detection of diastolic dysfunction in a mouse model of myocardial infarction. An in-house, high-temporal-resolution, retrospectively gated CINE sequence was developed with a temporal resolution of 1 ms. Diastolic function in mice was assessed using a custom-made, open-source reconstruction package. Early (E) and late (A) left ventricular filling phases were easily identifiable, and these measurements were compared directly with high-frequency, pulsed-wave, Doppler ultrasound measurements of mitral valve inflow. A repeatability study established that high-temporal-resolution CINE MRI and Doppler ultrasound showed comparable accuracy when measuring E/A in normal control mice. However, when applied in a mouse model of myocardial infarction, high-temporal-resolution CINE MRI indicated diastolic heart failure (E/A = 0.94 ± 0.11), whereas ultrasound falsely detected normal cardiac function (E/A = 1.21 ± 0.11). The addition of high-temporal-resolution CINE MRI to preclinical imaging studies enhances the library of sequences available to cardiac researchers and potentially identifies diastolic heart failure early in disease progression. © 2017 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.

  12. TU-FG-201-06: Remote Dosimetric Auditing for Clinical Trials Using EPID Dosimetry: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Miri, N; Legge, K; Greer, P [Newcastle University, Newcastle, NSW (Australia); Lehmann, J [Calvary Mater Newcastle, Newcastle, NSW (Australia); Vial, P [Liverpool Hospital, Sydney, NSW (Australia)

    2016-06-15

    Purpose: To perform a pilot study for remote dosimetric credentialing of intensity modulated radiation therapy (IMRT) based clinical trials. The study introduces a novel, time efficient and inexpensive dosimetry audit method for multi-center credentialing. The method employs electronic portal imaging device (EPID) to reconstruct delivered dose inside a virtual flat/cylindrical water phantom. Methods: Five centers, including different accelerator types and treatment planning systems (TPS), were asked to download two CT data sets of a Head and Neck (H&N) and Postprostatectomy (P-P) patients to produce benchmark plans. These were then transferred to virtual flat and cylindrical phantom data sets that were also provided. In-air EPID images of the plans were then acquired, and the data sent to the central site for analysis. At the central site, these were converted to DICOM format, all images were used to reconstruct 2D and 3D dose distributions inside respectively the flat and cylindrical phantoms using inhouse EPID to dose conversion software. 2D dose was calculated for individual fields and 3D dose for the combined fields. The results were compared to corresponding TPS doses. Three gamma criteria were used, 3%3mm-3%/2mm–2%/2mm with a 10% dose threshold, to compare the calculated and prescribed dose. Results: All centers had a high pass rate for the criteria of 3%/3 mm. For 2D dose, the average of centers mean pass rate was 99.6% (SD: 0.3%) and 99.8% (SD: 0.3%) for respectively H&N and PP patients. For 3D dose, 3D gamma was used to compare the model dose with TPS combined dose. The mean pass rate was 97.7% (SD: 2.8%) and 98.3% (SD: 1.6%). Conclusion: Successful performance of the method for the pilot centers establishes the method for dosimetric multi-center credentialing. The results are promising and show a high level of gamma agreement and, the procedure is efficient, consistent and inexpensive. Funding has been provided from Department of Radiation Oncology

  13. Evaluation of two methods of predicting MLC leaf positions using EPID measurements

    International Nuclear Information System (INIS)

    Parent, Laure; Seco, Joao; Evans, Phil M.; Dance, David R.; Fielding, Andrew

    2006-01-01

    In intensity modulated radiation treatments (IMRT), the position of the field edges and the modulation within the beam are often achieved with a multileaf collimator (MLC). During the MLC calibration process, due to the finite accuracy of leaf position measurements, a systematic error may be introduced to leaf positions. Thereafter leaf positions of the MLC depend on the systematic error introduced on each leaf during MLC calibration and on the accuracy of the leaf position control system (random errors). This study presents and evaluates two methods to predict the systematic errors on the leaf positions introduced during the MLC calibration. The two presented methods are based on a series of electronic portal imaging device (EPID) measurements. A comparison with film measurements showed that the EPID could be used to measure leaf positions without introducing any bias. The first method, referred to as the 'central leaf method', is based on the method currently used at this center for MLC leaf calibration. It mimics the manner in which leaf calibration parameters are specified in the MLC control system and consequently is also used by other centers. The second method, a new method proposed by the authors and referred to as the ''individual leaf method,'' involves the measurement of two positions for each leaf (-5 and +15 cm) and the interpolation and extrapolation from these two points to any other given position. The central leaf method and the individual leaf method predicted leaf positions at prescribed positions of -11, 0, 5, and 10 cm within 2.3 and 1.0 mm, respectively, with a standard deviation (SD) of 0.3 and 0.2 mm, respectively. The individual leaf method provided a better prediction of the leaf positions than the central leaf method. Reproducibility tests for leaf positions of -5 and +15 cm were performed. The reproducibility was within 0.4 mm on the same day and 0.4 mm six weeks later (1 SD). Measurements at gantry angles of 0 deg., 90 deg., and 270 deg

  14. A quantitative method to the analysis of MLC leaf position and speed based on EPID and EBT3 film for dynamic IMRT treatment with different types of MLC.

    Science.gov (United States)

    Li, Yinghui; Chen, Lixin; Zhu, Jinhan; Wang, Bin; Liu, Xiaowei

    2017-07-01

    A quantitative method based on the electronic portal imaging system (EPID) and film was developed for MLC position and speed testing; this method was used for three MLC types (Millennium, MLCi, and Agility MLC). To determine the leaf position, a picket fence designed by the dynamic (DMLC) model was used. The full-width half-maximum (FWHM) values of each gap measured by EPID and EBT3 were converted to the gap width using the FWHM versus nominal gap width relationship. The algorithm developed for the picket fence analysis was able to quantify the gap width, the distance between gaps, and each individual leaf position. To determine the leaf speed, a 0.5 × 20 cm 2 MLC-defined sliding gap was applied across a 14 × 20 cm 2 symmetry field. The linacs ran at a fixed-dose rate. The use of different monitor units (MUs) for this test led to different leaf speeds. The effect of leaf transmission was considered in a speed accuracy analysis. The difference between the EPID and film results for the MLC position is less than 0.1 mm. For the three MLC types, twice the standard deviation (2 SD) is provided; 0.2, 0.4, and 0.4 mm for gap widths of three MLC types, and 0.1, 0.2, and 0.2 mm for distances between gaps. The individual leaf positions deviate from the preset positions within 0.1 mm. The variations in the speed profiles for the EPID and EBT3 results are consistent, but the EPID results are slightly better than the film results. Different speeds were measured for each MLC type. For all three MLC types, speed errors increase with increasing speed. The analysis speeds deviate from the preset speeds within approximately 0.01 cm s -1 . This quantitative analysis of MLC position and speed provides an intuitive evaluation for MLC quality assurance (QA). © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  15. Coronary endothelial function assessment using self-gated cardiac cine MRI and k-t sparse SENSE.

    Science.gov (United States)

    Yerly, Jérôme; Ginami, Giulia; Nordio, Giovanna; Coristine, Andrew J; Coppo, Simone; Monney, Pierre; Stuber, Matthias

    2016-11-01

    Electrocardiogram (ECG)-gated cine MRI, paired with isometric handgrip exercise, can be used to accurately, reproducibly, and noninvasively measure coronary endothelial function (CEF). Obtaining a reliable ECG signal at higher field strengths, however, can be challenging due to rapid gradient switching and an increased heart rate under stress. To address these limitations, we present a self-gated cardiac cine MRI framework for CEF measurements that operates without ECG signal. Cross-sectional slices of the right coronary artery (RCA) were acquired using a two-dimensional golden angle radial trajectory. This sampling approach, combined with the k-t sparse SENSE algorithm, allows for the reconstruction of both real-time images for self-gating signal calculations and retrospectively reordered self-gated cine images. CEF measurements were quantitatively compared using both the self-gated and the standard ECG-gated approach. Self-gated cine images with high-quality, temporal, and spatial resolution were reconstructed for 18 healthy volunteers. CEF as measured in self-gated images was in good agreement (R 2  = 0.60) with that measured by its standard ECG-gated counterpart. High spatial and temporal resolution cross-sectional cine images of the RCA can be obtained without ECG signal. The coronary vasomotor response to handgrip exercise compares favorably with that obtained with the standard ECG-gated method. Magn Reson Med 76:1443-1454, 2015. © 2015 International Society for Magnetic Resonance in Medicine. © 2015 International Society for Magnetic Resonance in Medicine.

  16. Friday Programme for CineGlobe 2015

    CERN Multimedia

    Marcelloni De Oliveira, Claudia

    2015-01-01

    Workshops, apero with filmmakers and short-films inspired by science were the menu of the festival through the day. At night the CineGlobe DOME shown with the 360 degree projections shot-films; among them the avant-premiere of "Phantom of the Universe" - a movie that explains Dark Matter, directed by Joao Pequenao. Meanwhile at the Globe, the audience could enjoy the projections of the sequence of " The Invisible Photograph" .

  17. Entre la Historia y el Cine

    Directory of Open Access Journals (Sweden)

    Luisa Fernanda Acosta

    1995-01-01

    Full Text Available Este trabajo se propone aplicar al cine el concepto de «fuente histórica». El uso de medios de comunicación como el cine está íntimamente relacionado con las necesidades y posibilidades de una sociedad, lo que implica una relación muy cercana entre el desarrollo social y económico de una comunidad, y los mecanismos que ella genera como canales de expresión y comunicación. El cine, conjugación de imagen, sonido y movimiento se convierte para la sociedades contemporáneas en una gran alternativa como fuente histórica, que provee al investigador ópticas diferentes de una realidad ya explorada. Un gesto, una mirada, un plano, una secuencia, se traducen en frases y párrafos, que generan una versión diferente de la historia, una redacción que se lee en imágenes y que narra otro punto de vista, un relato oculto que tiene todo por contar.

  18. A methodology to determine margins by EPID measurements of patient setup variation and motion as applied to immobilization devices

    International Nuclear Information System (INIS)

    Prisciandaro, Joann I.; Frechette, Christina M.; Herman, Michael G.; Brown, Paul D.; Garces, Yolanda I.; Foote, Robert L.

    2004-01-01

    Assessment of clinic and site specific margins are essential for the effective use of three-dimensional and intensity modulated radiation therapy. An electronic portal imaging device (EPID) based methodology is introduced which allows individual and population based CTV-to-PTV margins to be determined and compared with traditional margins prescribed during treatment. This method was applied to a patient cohort receiving external beam head and neck radiotherapy under an IRB approved protocol. Although the full study involved the use of an EPID-based method to assess the impact of (1) simulation technique (2) immobilization, and (3) surgical intervention on inter- and intrafraction variations of individual and population-based CTV-to-PTV margins, the focus of the paper is on the technique. As an illustration, the methodology is utilized to examine the influence of two immobilization devices, the UON TM thermoplastic mask and the Type-S TM head/neck shoulder immobilization system on margins. Daily through port images were acquired for selected fields for each patient with an EPID. To analyze these images, simulation films or digitally reconstructed radiographs (DRR's) were imported into the EPID software. Up to five anatomical landmarks were identified and outlined by the clinician and up to three of these structures were matched for each reference image. Once the individual based errors were quantified, the patient results were grouped into populations by matched anatomical structures and immobilization device. The variation within the subgroup was quantified by calculating the systematic and random errors (Σ sub and σ sub ). Individual patient margins were approximated as 1.65 times the individual-based random error and ranged from 1.1 to 6.3 mm (A-P) and 1.1 to 12.3 mm (S-I) for fields matched on skull and cervical structures, and 1.7 to 10.2 mm (L-R) and 2.0 to 13.8 mm (S-I) for supraclavicular fields. Population-based margins ranging from 5.1 to 6.6 mm (A

  19. Accuracy of respiratory motion measurement of 4D-MRI: A comparison between cine and sequential acquisition.

    Science.gov (United States)

    Liu, Yilin; Yin, Fang-Fang; Rhee, DongJoo; Cai, Jing

    2016-01-01

    The authors have recently developed a cine-mode T2*/T1-weighted 4D-MRI technique and a sequential-mode T2-weighted 4D-MRI technique for imaging respiratory motion. This study aims at investigating which 4D-MRI image acquisition mode, cine or sequential, provides more accurate measurement of organ motion during respiration. A 4D digital extended cardiac-torso (XCAT) human phantom with a hypothesized tumor was used to simulate the image acquisition and the 4D-MRI reconstruction. The respiratory motion was controlled by the given breathing signal profiles. The tumor was manipulated to move continuously with the surrounding tissue. The motion trajectories were measured from both sequential- and cine-mode 4D-MRI images. The measured trajectories were compared with the average trajectory calculated from the input profiles, which was used as references. The error in 4D-MRI tumor motion trajectory (E) was determined. In addition, the corresponding respiratory motion amplitudes of all the selected 2D images for 4D reconstruction were recorded. Each of the amplitude was compared with the amplitude of its associated bin on the average breathing curve. The mean differences from the average breathing curve across all slice positions (D) were calculated. A total of 500 simulated respiratory profiles with a wide range of irregularity (Ir) were used to investigate the relationship between D and Ir. Furthermore, statistical analysis of E and D using XCAT controlled by 20 cancer patients' breathing profiles was conducted. Wilcoxon Signed Rank test was conducted to compare two modes. D increased faster for cine-mode (D = 1.17 × Ir + 0.23) than sequential-mode (D = 0.47 × Ir + 0.23) as irregularity increased. For the XCAT study using 20 cancer patients' breathing profiles, the median E values were significantly different: 0.12 and 0.10 cm for cine- and sequential-modes, respectively, with a p-value of 0.02. The median D values were significantly different: 0.47 and 0.24 cm for cine

  20. TU-FG-201-01: 18-Month Clinical Experience of a Linac Daily Quality Assurance (QA) Solution Using Only EPID and OBI

    Energy Technology Data Exchange (ETDEWEB)

    Cai, B; Sun, B; Yaddanapudi, S; Goddu, S; Li, H; Caruthers, D; Kavanaugh, J; Mutic, S [Washington University School of Medicine, Saint Louis, MO (United States)

    2016-06-15

    Purpose: To describe the clinical use of a Linear Accelerator (Linac) DailyQA system with only EPID and OBI. To assess the reliability over an 18-month period and improve the robustness of this system based on QA failure analysis. Methods: A DailyQA solution utilizing an in-house designed phantom, combined EPID and OBI image acquisitions, and a web-based data analysis and reporting system was commissioned and used in our clinic to measure geometric, dosimetry and imaging components of a Varian Truebeam Linac. During an 18-month period (335 working days), the Daily QA results, including the output constancy, beam flatness and symmetry, uniformity, TPR20/10, MV and KV imaging quality, were collected and analyzed. For output constancy measurement, an independent monthly QA system with an ionization chamber (IC) and annual/incidental TG51 measurements with ADCL IC were performed and cross-compared to Daily QA system. Thorough analyses were performed on the recorded QA failures to evaluate the machine performance, optimize the data analysis algorithm, adjust the tolerance setting and improve the training procedure to prevent future failures. Results: A clinical workflow including beam delivery, data analysis, QA report generation and physics approval was established and optimized to suit daily clinical operation. The output tests over the 335 working day period cross-correlated with the monthly QA system within 1.3% and TG51 results within 1%. QA passed with one attempt on 236 days out of 335 days. Based on the QA failures analysis, the Gamma criteria is revised from (1%, 1mm) to (2%, 1mm) considering both QA accuracy and efficiency. Data analysis algorithm is improved to handle multiple entries for a repeating test. Conclusion: We described our 18-month clinical experience on a novel DailyQA system using only EPID and OBI. The long term data presented demonstrated the system is suitable and reliable for Linac daily QA.

  1. Nonrigid motion compensation in compressed sensing reconstruction of cardiac cine MRI.

    Science.gov (United States)

    Tolouee, Azar; Alirezaie, Javad; Babyn, Paul

    2018-02-01

    In this work, a robust nonrigid motion compensation approach, is applied to the compressed sensing reconstruction of dynamic cardiac cine MRI sequences. Respiratory and cardiac motion separation coupled with a registration algorithm is used to provide accurate reconstruction of dynamic cardiac images. The proposed scheme employs a variable splitting based optimization strategy to enable joint motion estimation along with reconstruction. We define the recovery as an energy minimization scheme utilizing an objective function that combines data consistency, spatial smoothness, and motion penalties. The validation of the proposed algorithm using numerical phantom and in-vivo cine MRI data demonstrates reconstruction of cardiac MRI data with less spatio-temporal blurring and motion artifacts from extensively under-sampled data. The proposed method is observed to provide improved reconstructions over state-of-the-art motion compensation schemes. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Manifold learning based ECG-free free-breathing cardiac CINE MRI.

    Science.gov (United States)

    Usman, Muhammad; Atkinson, David; Kolbitsch, Christoph; Schaeffter, Tobias; Prieto, Claudia

    2015-06-01

    To present and validate a manifold learning (ML)-based method that can estimate both cardiac and respiratory navigator signals from electrocardiogram (ECG)-free free-breathing cardiac magnetic resonance imaging (MRI) data to achieve self-gated retrospective CINE reconstruction. In this work the use of the ML method is demonstrated for 2D cardiac CINE to achieve both cardiac and respiratory self-gating without the need of an external navigator or ECG signal. This is achieved by sequentially applying ML to two sets of retrospectively reconstructed real-time images with differing temporal resolutions. A 1D cardiac signal is estimated by applying ML to high temporal resolution real-time images reconstructed from the acquired data. Using the estimated cardiac signal, a 1D respiratory signal was obtained by applying the ML method to low temporal resolution images reconstructed from the same acquired data for each cardiac cycle. Data were acquired in five volunteers with a 2D golden angle radial trajectory in a balanced steady-state free precession (b-SSFP) acquisition. The accuracy of the estimated cardiac signal was calculated as the standard deviation of the temporal difference between the estimated signal and the recorded ECG. The correlation between the estimated respiratory signal and standard pencil beam navigator signal was evaluated. Gated CINE reconstructions (20 cardiac phases per cycle, temporal resolution ∼30 msec) using the estimated cardiac and respiratory signals were qualitatively compared against conventional ECG-gated breath-hold CINE acquisitions. Accurate cardiac signals were estimated with the proposed method, with an error standard deviation in comparison to ECG lower than 20 msec. Respiratory signals estimated with the proposed method achieved a mean cross-correlation of 94% with respect to standard pencil beam navigator signals. Good quality visual scores of 2.80 ± 0.45 (scores from 0, bad, to 4, excellent quality) were observed for the

  3. El cine de terror español

    OpenAIRE

    Gómez Llorente, Tatiana

    2015-01-01

    La autora comienza haciendo un estudio del cine de terror desde sus inicios, sus subgéneros, mecanimos utilizados para provocar el miedo en el espectador para finalmente centrarse en el cine de terror español a través de cinco películas representativas del género.

  4. Self-gated golden angle spiral cine MRI for coronary endothelial function assessment.

    Science.gov (United States)

    Bonanno, Gabriele; Hays, Allison G; Weiss, Robert G; Schär, Michael

    2018-08-01

    Depressed coronary endothelial function (CEF) is a marker for atherosclerotic disease, an independent predictor of cardiovascular events, and can be quantified non-invasively with ECG-triggered spiral cine MRI combined with isometric handgrip exercise (IHE). However, MRI-CEF measures can be hindered by faulty ECG-triggering, leading to prolonged breath-holds and degraded image quality. Here, a self-gated golden angle spiral method (SG-GA) is proposed to eliminate the need for ECG during cine MRI. SG-GA was tested against retrospectively ECG-gated golden angle spiral MRI (ECG-GA) and gold-standard ECG-triggered spiral cine MRI (ECG-STD) in 10 healthy volunteers. CEF data were obtained from cross-sectional images of the proximal right and left coronary arteries in a 3T scanner. Self-gating heart rates were compared to those from simultaneous ECG-gating. Coronary vessel sharpness and cross-sectional area (CSA) change with IHE were compared among the 3 methods. Self-gating precision, accuracy, and correlation-coefficient were 7.7 ± 0.5 ms, 9.1 ± 0.7 ms, and 0.93 ± 0.01, respectively (mean ± standard error). Vessel sharpness by SG-GA was equal or higher than ECG-STD (rest: 63.0 ± 1.7% vs. 61.3 ± 1.3%; exercise: 62.6 ± 1.3% vs. 56.7 ± 1.6%, P cine MRI method even when ECG is faulty or not available. Magn Reson Med 80:560-570, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  5. Evaluation of potential internal target volume of liver tumors using cine-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Akino, Yuichi, E-mail: akino@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 5650871, Japan and Miyakojima IGRT Clinic, Miyakojima-ku, Osaka 5340021 (Japan); Oh, Ryoong-Jin; Masai, Norihisa; Shiomi, Hiroya; Inoue, Toshihiko [Miyakojima IGRT Clinic, Miyakojima-ku, Osaka 5340021 (Japan)

    2014-11-01

    Purpose: Four-dimensional computed tomography (4DCT) is widely used for evaluating moving tumors, including lung and liver cancers. For patients with unstable respiration, however, the 4DCT may not visualize tumor motion properly. High-speed magnetic resonance imaging (MRI) sequences (cine-MRI) permit direct visualization of respiratory motion of liver tumors without considering radiation dose exposure to patients. Here, the authors demonstrated a technique for evaluating internal target volume (ITV) with consideration of respiratory variation using cine-MRI. Methods: The authors retrospectively evaluated six patients who received stereotactic body radiotherapy (SBRT) to hepatocellular carcinoma. Before acquiring planning CT, sagittal and coronal cine-MRI images were acquired for 30 s with a frame rate of 2 frames/s. The patient immobilization was conducted under the same condition as SBRT. Planning CT images were then acquired within 15 min from cine-MRI image acquisitions, followed by a 4DCT scan. To calculate tumor motion, the motion vectors between two continuous frames of cine-MRI images were calculated for each frame using the pyramidal Lucas–Kanade method. The target contour was delineated on one frame, and each vertex of the contour was shifted and copied onto the following frame using neighboring motion vectors. 3D trajectory data were generated with the centroid of the contours on sagittal and coronal images. To evaluate the accuracy of the tracking method, the motion of clearly visible blood vessel was analyzed with the motion tracking and manual detection techniques. The target volume delineated on the 50% (end-exhale) phase of 4DCT was translated with the trajectory data, and the distribution of the occupancy probability of target volume was calculated as potential ITV (ITV {sub Potential}). The concordance between ITV {sub Potential} and ITV estimated with 4DCT (ITV {sub 4DCT}) was evaluated using the Dice’s similarity coefficient (DSC). Results

  6. Evaluation of potential internal target volume of liver tumors using cine-MRI.

    Science.gov (United States)

    Akino, Yuichi; Oh, Ryoong-Jin; Masai, Norihisa; Shiomi, Hiroya; Inoue, Toshihiko

    2014-11-01

    Four-dimensional computed tomography (4DCT) is widely used for evaluating moving tumors, including lung and liver cancers. For patients with unstable respiration, however, the 4DCT may not visualize tumor motion properly. High-speed magnetic resonance imaging (MRI) sequences (cine-MRI) permit direct visualization of respiratory motion of liver tumors without considering radiation dose exposure to patients. Here, the authors demonstrated a technique for evaluating internal target volume (ITV) with consideration of respiratory variation using cine-MRI. The authors retrospectively evaluated six patients who received stereotactic body radiotherapy (SBRT) to hepatocellular carcinoma. Before acquiring planning CT, sagittal and coronal cine-MRI images were acquired for 30 s with a frame rate of 2 frames/s. The patient immobilization was conducted under the same condition as SBRT. Planning CT images were then acquired within 15 min from cine-MRI image acquisitions, followed by a 4DCT scan. To calculate tumor motion, the motion vectors between two continuous frames of cine-MRI images were calculated for each frame using the pyramidal Lucas-Kanade method. The target contour was delineated on one frame, and each vertex of the contour was shifted and copied onto the following frame using neighboring motion vectors. 3D trajectory data were generated with the centroid of the contours on sagittal and coronal images. To evaluate the accuracy of the tracking method, the motion of clearly visible blood vessel was analyzed with the motion tracking and manual detection techniques. The target volume delineated on the 50% (end-exhale) phase of 4DCT was translated with the trajectory data, and the distribution of the occupancy probability of target volume was calculated as potential ITV (ITV Potential). The concordance between ITV Potential and ITV estimated with 4DCT (ITV 4DCT) was evaluated using the Dice's similarity coefficient (DSC). The distance between blood vessel positions

  7. Investigation of the mechanical performance of Siemens linacs components during arc: gantry, MLC, and electronic portal imaging device.

    Science.gov (United States)

    Rowshanfarzad, Pejman; Häring, Peter; Riis, Hans L; Zimmermann, Sune J; Ebert, Martin A

    2015-01-01

    In radiotherapy treatments, it is crucial to monitor the performance of linac components including gantry, collimation system, and electronic portal imaging device (EPID) during arc deliveries. In this study, a simple EPID-based measurement method is suggested in conjunction with an algorithm to investigate the stability of these systems at various gantry angles with the aim of evaluating machine-related errors in treatments. The EPID sag, gantry sag, changes in source-to-detector distance (SDD), EPID and collimator skewness, EPID tilt, and the sag in leaf bank assembly due to linac rotation were separately investigated by acquisition of 37 EPID images of a simple phantom with five ball bearings at various gantry angles. A fast and robust software package was developed for automated analysis of image data. Three Siemens linacs were investigated. The average EPID sag was within 1 mm for all tested linacs. Two machines showed >1 mm gantry sag. Changes in the SDD values were within 7.5 mm. EPID skewness and tilt values were Siemens linac components with gantry rotation. Such a comprehensive study has been performed for the first time on Siemens machines.

  8. SU-F-T-262: Commissioning Varian Portal Dosimetry for EPID-Based Patient Specific QA in a Non-Aria Environment

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, M; Knutson, N [Rhode Island Hospital, Providence RI (United States); University of Rhode Island, Kingston, RI (United States); University of Massachusetts Lowell, Lowell, MA (United States); Herrington, J [University of Rhode Island, Kingston, RI (United States); Price, M [Rhode Island Hospital, Providence RI (United States); University of Rhode Island, Kingston, RI (United States); Alpert Medical School of Brown University, Providence, RI (United States)

    2016-06-15

    Purpose: Development of an in-house program facilitates a workflow that allows Electronic Portal Imaging Device (EPID) patient specific quality assurance (QA) measurements to be acquired and analyzed in the Portal Dosimetry Application (Varian Medical Systems, Palo Alto, CA) using a non-Aria Record and Verify (R&V) system (MOSAIQ, Elekta, Crawley, UK) to deliver beams in standard clinical treatment mode. Methods: Initial calibration of an in-house software tool includes characterization of EPID dosimetry parameters by importing DICOM images of varying delivered MUs to determine linear mapping factors in order to convert image pixel values to Varian-defined Calibrated Units (CU). Using this information, the Portal Dose Image Prediction (PDIP) algorithm was commissioned by converting images of various field sizes to output factors using the Eclipse Scripting Application Programming Interface (ESAPI) and converting a delivered configuration fluence to absolute dose units. To verify the algorithm configuration, an integrated image was acquired, exported directly from the R&V client, automatically converted to a compatible, calibrated dosimetric image, and compared to a PDIP calculated image using Varian’s Portal Dosimetry Application. Results: For two C-Series and one TrueBeam Varian linear accelerators, gamma comparisons (global 3% / 3mm) of PDIP algorithm predicted dosimetric images and images converted via the inhouse system demonstrated agreement for ≥99% of all pixels, exceeding vendor-recommended commissioning guidelines. Conclusion: Combinations of a programmatic image conversion tool and ESAPI allow for an efficient and accurate method of patient IMRT QA incorporating a 3rd party R&V system.

  9. The exposure of radiologists and patients to radiation during coronary angiography and percutaneous transluminal coronary angioplasty (PTCA). The performance of cine x-ray equipment and film processing; Saeteilyaltistus sydaenangiografiatutkimuksissa ja kineangiografialaitteiden toimintakunto

    Energy Technology Data Exchange (ETDEWEB)

    Karppinen, J.; Parviainen, T.

    1993-03-01

    The exposure of radiologists and patients to radiation during coronary angiography and percutaneous transluminal coronary angioplasty (PTCA) in Finland was studied using phantom measurements. Additional tests were made concerning the performance of TV fluoroscopy systems, cine fluorographic units and film processing. These tests include sensitometric quality control of film processing, automatic exposure control in fluoroscopy and cinefluorography, and contrast and resolution in a cine frame and TV image.

  10. Image timing and detector performance of a matrix ion-chamber electronic portal imaging device

    International Nuclear Information System (INIS)

    Greer, P.

    1996-01-01

    The Oncology Centre of Auckland Hospital recently purchased a Varian PortalVision TM electronic portal imaging device (EPID). Image acquisition times, input-output characteristics and contrast-detail curves of this matrix liquid ion-chamber EPID have been measured to examine the variation in imaging performance with acquisition mode. The variation in detector performance with acquisition mode has been examined. The HV cycle time can be increased to improve image quality. Consideration should be given to the acquisition mode and HV cycle time used when imaging to ensure adequate imaging performance with reasonable imaging time. (author)

  11. SU-E-T-133: Assessing IMRT Treatment Delivery Accuracy and Consistency On a Varian TrueBeam Using the SunNuclear PerFraction EPID Dosimetry Software

    Energy Technology Data Exchange (ETDEWEB)

    Dieterich, S [UC Davis Medical Center, Sacramento, CA (United States); Trestrail, E; Holt, R [Pacific Crest Medical Physics, Chico, CA (United States); Saini, S [Sun Nuclear Corporation, Melbourne, FL (Australia); Pfeiffer, I [VMTH, UC Davis, Davis, CA (United States); Kent, M; Hansen, K [Surgical and Radiological Sciences, UC Davis, Davis, CA (United States)

    2015-06-15

    Purpose: To assess if the TrueBeam HD120 collimator is delivering small IMRT fields accurately and consistently throughout the course of treatment using the SunNuclear PerFraction software. Methods: 7-field IMRT plans for 8 canine patients who passed IMRT QA using SunNuclear Mapcheck DQA were selected for this study. The animals were setup using CBCT image guidance. The EPID fluence maps were captured for each treatment field and each treatment fraction, with the first fraction EPID data serving as the baseline for comparison. The Sun Nuclear PerFraction Software was used to compare the EPID data for subsequent fractions using a Gamma (3%/3mm) pass rate of 90%. To simulate requirements for SRS, the data was reanalyzed using a Gamma (3%/1mm) pass rate of 90%. Low-dose, low- and high gradient thresholds were used to focus the analysis on clinically relevant parts of the dose distribution. Results: Not all fractions could be analyzed, because during some of the treatment courses the DICOM tags in the EPID images intermittently change from CU to US (unspecified), which would indicate a temporary loss of EPID calibration. This technical issue is still being investigated. For the remaining fractions, the vast majority (7/8 of patients, 95% of fractions, and 96.6% of fields) are passing the less stringent Gamma criteria. The more stringent Gamma criteria caused a drop in pass rate (90 % of fractions, 84% of fields). For the patient with the lowest pass rate, wet towel bolus was used. Another patient with low pass rates experienced masseter muscle wasting. Conclusion: EPID dosimetry using the PerFraction software demonstrated that the majority of fields passed a Gamma (3%/3mm) for IMRT treatments delivered with a TrueBeam HD120 MLC. Pass rates dropped for a DTA of 1mm to model SRS tolerances. PerFraction pass rates can flag missing bolus or internal shields. Sanjeev Saini is an employee of Sun Nuclear Corporation. For this study, a pre-release version of PerFRACTION 1

  12. Validation of in vivo 2D displacements from spiral cine DENSE at 3T.

    Science.gov (United States)

    Wehner, Gregory J; Suever, Jonathan D; Haggerty, Christopher M; Jing, Linyuan; Powell, David K; Hamlet, Sean M; Grabau, Jonathan D; Mojsejenko, Walter Dimitri; Zhong, Xiaodong; Epstein, Frederick H; Fornwalt, Brandon K

    2015-01-30

    Displacement Encoding with Stimulated Echoes (DENSE) encodes displacement into the phase of the magnetic resonance signal. Due to the stimulated echo, the signal is inherently low and fades through the cardiac cycle. To compensate, a spiral acquisition has been used at 1.5T. This spiral sequence has not been validated at 3T, where the increased signal would be valuable, but field inhomogeneities may result in measurement errors. We hypothesized that spiral cine DENSE is valid at 3T and tested this hypothesis by measuring displacement errors at both 1.5T and 3T in vivo. Two-dimensional spiral cine DENSE and tagged imaging of the left ventricle were performed on ten healthy subjects at 3T and six healthy subjects at 1.5T. Intersection points were identified on tagged images near end-systole. Displacements from the DENSE images were used to project those points back to their origins. The deviation from a perfect grid was used as a measure of accuracy and quantified as root-mean-squared error. This measure was compared between 3T and 1.5T with the Wilcoxon rank sum test. Inter-observer variability of strains and torsion quantified by DENSE and agreement between DENSE and harmonic phase (HARP) were assessed by Bland-Altman analyses. The signal to noise ratio (SNR) at each cardiac phase was compared between 3T and 1.5T with the Wilcoxon rank sum test. The displacement accuracy of spiral cine DENSE was not different between 3T and 1.5T (1.2 ± 0.3 mm and 1.2 ± 0.4 mm, respectively). Both values were lower than the DENSE pixel spacing of 2.8 mm. There were no substantial differences in inter-observer variability of DENSE or agreement of DENSE and HARP between 3T and 1.5T. Relative to 1.5T, the SNR at 3T was greater by a factor of 1.4 ± 0.3. The spiral cine DENSE acquisition that has been used at 1.5T to measure cardiac displacements can be applied at 3T with equivalent accuracy. The inter-observer variability and agreement of DENSE-derived peak strains and

  13. Necrolisis epidérmica tóxica y lupus eritematoso sistémico

    Directory of Open Access Journals (Sweden)

    Amauri Lázaro Noda Albelo

    Full Text Available La necrolisis epidérmica tóxica es el resultado de una reacción mucocutánea aguda severa. La frecuencia con que ocurre esta enfermedad es superior en estados patológicos, cuando existe una respuesta inmune «aberrante», incluida enfermedad injerto contra huésped, cáncer, infección por VIH y enfermedades autoinmunes. Se describe un caso que cumple con los criterios diagnósticos de lupus eritematoso sistémico y necrolisis epidérmica tóxica.

  14. Free breathing whole-heart 3D CINE MRI with self-gated Cartesian trajectory.

    Science.gov (United States)

    Usman, M; Ruijsink, B; Nazir, M S; Cruz, G; Prieto, C

    2017-05-01

    To present a method that uses a novel free-running self-gated acquisition to achieve isotropic resolution in whole heart 3D Cartesian cardiac CINE MRI. 3D cardiac CINE MRI using navigator gating results in long acquisition times. Recently, several frameworks based on self-gated non-Cartesian trajectories have been proposed to accelerate this acquisition. However, non-Cartesian reconstructions are computationally expensive due to gridding, particularly in 3D. In this work, we propose a novel highly efficient self-gated Cartesian approach for 3D cardiac CINE MRI. Acquisition is performed using CArtesian trajectory with Spiral PRofile ordering and Tiny golden angle step for eddy current reduction (so called here CASPR-Tiger). Data is acquired continuously under free breathing (retrospective ECG gating, no preparation pulses interruption) for 4-5min and 4D whole-heart volumes (3D+cardiac phases) with isotropic spatial resolution are reconstructed from all available data using a soft gating technique combined with temporal total variation (TV) constrained iterative SENSE reconstruction. For data acquired on eight healthy subjects and three patients, the reconstructed images using the proposed method had good contrast and spatio-temporal variations, correctly recovering diastolic and systolic cardiac phases. Non-significant differences (P>0.05) were observed in cardiac functional measurements obtained with proposed 3D approach and gold standard 2D multi-slice breath-hold acquisition. The proposed approach enables isotropic 3D whole heart Cartesian cardiac CINE MRI in 4 to 5min free breathing acquisition. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Treatment and diagnosis of middle fossa arachnoid cyst. Ventriculofiberscopy and cine-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kamikawa, Shuji; Kuwamura, Keiichi [Hyogo Prefectural Awaji Hospital, Sumoto (Japan); Tamaki, Norihiko

    1998-07-01

    The treatment of intracranial arachnoid cysts is controversial regarding its surgical indication and operative procedures. Conventional surgical approaches such as fenestration, membranectomy, and shunting operation are invasive. Also CT cisternography and/or RI cisternography are invasive, when it has been performed to evaluate the possible CSF communications between the arachnoid cyst and subarachnoid space. Between July 1994 and February 1997, 10 patients with intracranial middle fossa arachnoid cysts were treated with a newly developed ventriculofiberscope which is characterized by splendid mechanical flexibility and high resolution. The cine-MRI, which is a non-invasive diagnostic tool, is used to evaluate the CSF circulation around the cyst fenestration. The patients` ages ranged from 4 months to 10 years, with a mean of 4.46 years. The cyst locations were left middle fossa (9), and right (1). Eight patients presented with macrocrania, 4 with developmental delay, three with seizure, two with headache, and one with subdural hematoma. The patients were preoperatively evaluated by means of MRI and cine-MR images. In all patients ventriculofiberscopic procedures including cyst fenestration, membranous dissection, cyst puncture and shriveling were successfully performed. Postoperative MR and cine-MR studies have shown reduction of the cyst size and appropriate CSF circulation. Neuroendoscopic procedures seem to be the first choice for children with arachnoid cysts and the ventriculofiberscope proved to be very useful not only for cyst fenestration but also for cyst dissection. In addition, the non-invasive cine-MR studies are useful for long follow-up at OPD. (author)

  16. Erotismo, pornografía y cine

    Directory of Open Access Journals (Sweden)

    José Rojas Bez

    2015-01-01

    Full Text Available ¿Qué es el erotismo? ¿Qué es la pornografía? ¿En qué medida influyen sobre el espectador? Cómo responder educativamente ante las diversas manifestaciones suyas en el cine y los demás medios artísticos? El autor reflexiona sobre estas cuestiones esenciales, distingue ambos conceptos y propone respuestas desprejuiciadas, no preconcebidas, sino fundamentales, desde puntos de vista educativos, estéticos y críticos.

  17. Psicología y cine: TID

    OpenAIRE

    Nuñez García, Cristina

    2013-01-01

    Partiendo de la base de que en el día a día no podemos encontrar la mayoría de los trastornos que se encuentran en el DSM-IV y en el CIE-10, el cine nos hace un acercamiento a estos haciéndolos más divulgativos y ejemplificando dichos trastornos aunque no siempre con la realidad deseada. Por eso mismo vamos a tratar el trastorno de identidad disociativo para profundizar en él, trabajando desde la historia del mismo, sus características, diagnóstico,... Trataremos de ejemplificar casos de TID ...

  18. Basic dose response of fluorescent screen-based portal imaging device

    International Nuclear Information System (INIS)

    Yeo, In Hwan; Yonannes, Yonas; Zhu, Yunping

    1999-01-01

    The purpose of this study is to investigate fundamental aspects of the dose response of fluorescent screen-based electronic portal imaging devices (EPIDs). We acquired scanned signal across portal planes as we varied the radiation that entered the EPID by changing the thickness and anatomy of the phantom as well as the air gap between the phantom and the EPID. In addition, we simulated the relative contribution of the scintillation light signal in the EPID system. We have shown that the dose profile across portal planes is a function of the air gap and phantom thickness. We have also found that depending on the density change within the phantom geometry, errors associated with dose response based on the EPID scan can be as high as 7%. We also found that scintillation light scattering within the EPID system is an important source of error. This study revealed and demonstrated fundamental characteristics of dose response of EPID, as relative to that of ion chambers. This study showed that EPID based on fluorescent screen cannot be an accurate dosimetry system

  19. Prestigio de la nación vs mirada deconstruyente: las imágenes de Italia en el Festival Internacional de Cine de Venecia desde el final de la Segunda Guerra Mundial hasta el "milagro económico" / Nation’s Prestige vs Deconstructive Gaze: The Images of Italy since the End of the Second World War until

    Directory of Open Access Journals (Sweden)

    Stefano Pisu

    2016-08-01

    Full Text Available El presente artículo pretende investigar qué tipo de imágenes sobre Italia surgieron en el Festival Internacional de Cine de Venecia en el periodo comprendido entre la segunda posguerra europea y los años del llamado «milagro económico». En esos años se abrió una contradicción entre los éxitos conseguidos por las películas italianas –sobre todo en el extranjero– y la imagen de pobredumbre socieconómica que esos films transmitían. El político más influyente para la industria cinematográfica italiana en ese momento, el democristiano Giulio Andreotti, osciló entre el reconocimiento del valor comercial, cultural y diplomático de aquellos éxitos, pese a que las películas retrataban un país pobre, y la irritación explícita por su proyección en Italia y en el extranjero, hasta el punto de intentar censurarlas. Un análisis de la Mostra entre la segunda mitad de los años50 y la primera mitad de los 60, con su función de escaparate del «milagro económico», no permite conformar una única imagen de Italia. Por un lado, el festival de 1959 fue decisivo para relanzar el cine italiano, tanto dentro del país como en el extranjero, por el premio concedido a El general de la Rovere (Il generale dellaRovere, Roberto Rosellini y a La gran guerra (La grande guerra, Mario Monicelli, films que contribuyeron a la promoción de una imagen indulgente de los italianos, representados como astutos y sin embargo buenos, oportunistas pero, en el fondo, buena gente. Por otro lado, la Mostra no solo encumbró ese proceso de desarrollo económico y de modernización que atravesaba Italia; al mismo tiempo –y sobre todo– promovió una representación más problemática del país, de su pasado y de su presente.Palabras clave: Festival Internacional de Cine de Venecia, imágenes de la nación, cine italiano, posguerra, neorrealismo, milagro económico.AbstractThis article intends to investigate what kinds of Italy’s images emerged at the

  20. Isotropic 3D cardiac cine MRI allows efficient sparse segmentation strategies based on 3D surface reconstruction.

    Science.gov (United States)

    Odille, Freddy; Bustin, Aurélien; Liu, Shufang; Chen, Bailiang; Vuissoz, Pierre-André; Felblinger, Jacques; Bonnemains, Laurent

    2018-05-01

    Segmentation of cardiac cine MRI data is routinely used for the volumetric analysis of cardiac function. Conventionally, 2D contours are drawn on short-axis (SAX) image stacks with relatively thick slices (typically 8 mm). Here, an acquisition/reconstruction strategy is used for obtaining isotropic 3D cine datasets; reformatted slices are then used to optimize the manual segmentation workflow. Isotropic 3D cine datasets were obtained from multiple 2D cine stacks (acquired during free-breathing in SAX and long-axis (LAX) orientations) using nonrigid motion correction (cine-GRICS method) and super-resolution. Several manual segmentation strategies were then compared, including conventional SAX segmentation, LAX segmentation in three views only, and combinations of SAX and LAX slices. An implicit B-spline surface reconstruction algorithm is proposed to reconstruct the left ventricular cavity surface from the sparse set of 2D contours. All tested sparse segmentation strategies were in good agreement, with Dice scores above 0.9 despite using fewer slices (3-6 sparse slices instead of 8-10 contiguous SAX slices). When compared to independent phase-contrast flow measurements, stroke volumes computed from four or six sparse slices had slightly higher precision than conventional SAX segmentation (error standard deviation of 5.4 mL against 6.1 mL) at the cost of slightly lower accuracy (bias of -1.2 mL against 0.2 mL). Functional parameters also showed a trend to improved precision, including end-diastolic volumes, end-systolic volumes, and ejection fractions). The postprocessing workflow of 3D isotropic cardiac imaging strategies can be optimized using sparse segmentation and 3D surface reconstruction. Magn Reson Med 79:2665-2675, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  1. The Role of Routine Whole Volume SPECT Reconstruction in Comparison to Cine Raw Data in the Detection of Extracardiac Uptake on Myocardial Perfusion Scans

    International Nuclear Information System (INIS)

    Maharaj, M.; Korowlay, N.A.

    2011-01-01

    The objective of this study was to determine the role of routine whole volume reconstructed single-photon emission tomography (rSPECT) compared to cine raw data to detect extracardiac uptake of Sestamibi (MIBI). In a retrospective study, the myocardial perfusion studies of 426 patients were inspected separately for extracardiac uptake on cine raw data and rSPECT. The acquisition parameters for all the images were done according to departmental protocol. The whole volume SPECT data was selected and processed by HOSEM iterative reconstruction using the HERMES computer software system. The images were assessed by two observers, a student in training and a senior consultant nuclear medicine physician. The overall mean age and standard deviation of the 426 patients at the time of the study was 60 ± 12 years. Statistical analysis was performed using the Kappa and McNemars tests. The clinical significance of the extracardiac uptake was evaluated using hospital folders and /or laboratory results after viewing images. rSPECT detected 25 patients (5.9%) and cine raw data identified 18 patients (4.2%) with extracardiac uptake. All the areas of extracardiac uptake noted on cine raw data were seen on the rSPECT images. Only 21 of the 25 patients had complete 5-year clinical follow-up. The value of the clinical significance of the extracardiac uptake was limited due to the study being retrospective. The proportion of positives identified by rSPECT was significantly larger than those identified by cine raw data (P = 0.0082). Although our study demonstrates that rSPECT is more sensitive than cine raw data in detecting extracardiac uptake, it also shows that there is no benefit in routine whole volume rSPECT in daily clinical practice

  2. Comparison of cine-MRI and transthoracic echocardiography for the assessment of aortic root diameters in patients with suspected Marfan syndrome

    International Nuclear Information System (INIS)

    Bannas, P.; Derlin, T.; Yamamura, J.; Lund, G.; Adam, G.; Rybczynski, M.; Sheikhzadeh, S.; Kodolitsch, Y. von; Groth, M.

    2015-01-01

    Patients with Marfan syndrome require repeated imaging for monitoring of aortic root aneurysms. Therefore, we evaluated the agreement and reproducibility of cine-MRI and echocardiography measurements of the sinuses of Valsalva in patients with suspected Marfan syndrome. 51 consecutive patients with suspected Marfan syndrome were prospectively examined using cine-MRI and echocardiography. Two readers independently measured aortic root diameters at the level of the sinuses of Valsalva in both cine-MRI and echocardiography. Statistics included intraclass correlation coefficient, Pearson correlation coefficient, Bland-Altman analysis, and two-sided t-test. In 38 of the 51 individuals (74.5 %), the diagnosis of Marfan syndrome was established according to the criteria of the Ghent-2 nosology. Cine-MRI measurements of the sinuses of Valsalva revealed a strong correlation with echocardiography (r=0.929), but a statistically significant bias of -1.0 mm (p<0.001). The mean absolute diameter for sinuses of Valsalva obtained by cine-MRI was 32.3 ± 5.8 mm as compared to 33.4 ± 5.4 mm obtained by echocardiography. Interobserver agreement of measurements of the sinuses of Valsalva was higher for cine-MRI than for echocardiography (p=0.029). Despite small, but statistically significant differences in terms of agreement and reproducibility, cine-MRI and echocardiographic measurements of aortic root diameters provide comparable results without a significant clinical difference. Therefore both techniques may be used for monitoring of the aortic root in patients with Marfan syndrome.

  3. Comparison of cine-MRI and transthoracic echocardiography for the assessment of aortic root diameters in patients with suspected Marfan syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Bannas, P.; Derlin, T.; Yamamura, J.; Lund, G.; Adam, G. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Diagnostic and Interventional Radiology; Rybczynski, M.; Sheikhzadeh, S.; Kodolitsch, Y. von [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of General and Interventional Cardiology; Groth, M. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Section for Pediatric Radiology

    2015-11-15

    Patients with Marfan syndrome require repeated imaging for monitoring of aortic root aneurysms. Therefore, we evaluated the agreement and reproducibility of cine-MRI and echocardiography measurements of the sinuses of Valsalva in patients with suspected Marfan syndrome. 51 consecutive patients with suspected Marfan syndrome were prospectively examined using cine-MRI and echocardiography. Two readers independently measured aortic root diameters at the level of the sinuses of Valsalva in both cine-MRI and echocardiography. Statistics included intraclass correlation coefficient, Pearson correlation coefficient, Bland-Altman analysis, and two-sided t-test. In 38 of the 51 individuals (74.5 %), the diagnosis of Marfan syndrome was established according to the criteria of the Ghent-2 nosology. Cine-MRI measurements of the sinuses of Valsalva revealed a strong correlation with echocardiography (r=0.929), but a statistically significant bias of -1.0 mm (p<0.001). The mean absolute diameter for sinuses of Valsalva obtained by cine-MRI was 32.3 ± 5.8 mm as compared to 33.4 ± 5.4 mm obtained by echocardiography. Interobserver agreement of measurements of the sinuses of Valsalva was higher for cine-MRI than for echocardiography (p=0.029). Despite small, but statistically significant differences in terms of agreement and reproducibility, cine-MRI and echocardiographic measurements of aortic root diameters provide comparable results without a significant clinical difference. Therefore both techniques may be used for monitoring of the aortic root in patients with Marfan syndrome.

  4. Proust como en el cine

    Directory of Open Access Journals (Sweden)

    Julio César Moran

    2004-11-01

    Full Text Available The thesis of this paper is to show the way of Proust consideration in Le temps retrouvé which joins cinema with the mimetic art and literature of notes, it may be demostrated a lot of esthetics coincidences in the narrations and the theories, between the proustian world and the methods, resources and the utilization of the image by the cinema. It's a review of differents kind of films in relation with Proust's conception: we take time, espace, self, metacriticism, the likely and his conditions, the multiplicity of interpretations etc. into considerations.

  5. Clinical results of an EPID-based in-vivo dosimetry method for pelvic cancers treated by intensity-modulated radiation therapy.

    Science.gov (United States)

    Camilleri, J; Mazurier, J; Franck, D; Dudouet, P; Latorzeff, I; Franceries, X

    2014-09-01

    The purpose of our work was to investigate the feasibility of using an EPID-based in-vivo dosimetry method initially designed for conformal fields on pelvic dynamic IMRT fields. The method enables a point dose delivered to the patient to be calculated from the transit signal acquired with an electronic portal imaging device (EPID). After defining a set of correction factors allowing EPID pixel values to be converted into absolute doses, several tests on homogeneous water-equivalent phantoms were performed to estimate the validity of the method in reference conditions. The effects of different treatment parameters, such as delivered dose, field size dependence and patient thickness were also studied. The model was first evaluated on a group of 53 patients treated by 3D conformal radiotherapy (3DCRT) and then on 92 patients treated by IMRT, both for pelvic cancers. For each measurement, the dose was reconstructed at the isocenter (DREC) and compared with the dose calculated by our treatment planning system (DTPS). Excellent agreement was found between DREC and DTPS for both techniques. For 3DCRT treatments, the mean deviation between DREC and DTPS for the 211 in-vivo dose verifications was equal to -1.0  ±  2.2% (1SD). Concerning IMRT treatments, the averaged deviation for the 418 fields verified was equal to -0.3 ± 2.6% (1SD) proving that the method is able to reconstruct a dose for dynamic IMRT pelvic fields. Based on these results, tolerance criteria and action levels were established before its implementation in clinical routine. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  6. WE-DE-BRA-04: A Cost-Effective Pixelated EPID Scintillator for Enhanced Contrast and DQE

    Energy Technology Data Exchange (ETDEWEB)

    Rottmann, J; Myronakis, M; Hu, Y; Berbeco, R [Brigham and Woman’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA (United States); Shedlock, D; Wang, A; Humber, D; Star-Lack, J [Varian Medical Systems, Palo Alto, CA (United States); Morf, D; Fueglistaller, R [Varian Medical Systems, Daettwil (Switzerland)

    2016-06-15

    Purpose: Beams-eye-view imaging applications such as real-time soft-tissue motion estimation and MV-CBCT are hindered by the inherently low image contrast of electronic portal imaging devices (EPID) currently in clinical use. We investigate a cost effective scintillating glass that provides substantially increased detective quantum efficiency (DQE) and contrast to noise ratio (CNR). Methods: A pixelated scintillator prototype was built from LKH-5 glass. The array is 12mm thick; 42.4×42.4cm2 wide and features 1.51mm pixel pitch with 20µm separation (glue+septa). The LKH-5 array was mounted on the active matrix flat panel imager (AMPFI) of an AS-1200 (Varian) with the GdO2S2:Tb removed. A second AS-1200 was utilized as reference detector. The prototype EPID was characterized in terms of CNR, modulation transfer function (MTF) and DQE. Additionally, the visibility of various fiducial markers typically used in the clinic as well as a realistic 3D-printed lung tumor model was assessed. All items were placed in a 12cm thick solid water phantom. CNR is estimated using a Las Vegas contrast phantom, presampled MTF is estimated using a slanted slit technique and the DQE is calculated from measured normalized noise power spectra (NPS) and the MTF. Results: DQE(0) for the LKH-5 prototype increased by a factor of 8× to about 10%, compared to the AS-1200 equipped with its standard GdO2S2:Tb scintillator. CNR increased by a factor of 5.3×. Due to the pixel size the MTF50 decreased by about 55% to 0.23lp/mm. The visibility of all fiducial markers as well as the tumor model were however markedly improved in comparison to an acquisition with the same parameters using the GdO2S2:Tb scintillator. Conclusion: LKH-5 scintillating glasses allow the cost effective construction of thick pixelated scintillators for portal imaging which can yield a substantial increase in DQE and CNR. Soft tissue and fiducial marker visibility was found to be markedly improved. The project was supported

  7. Validation of regional myocardial perfusion with cine CT

    International Nuclear Information System (INIS)

    Gould, R.G.; McNamara, T.; Koshold, S.; Lipton, M.; Sievers, R.; Higgins, C.B.; Boyd, D.

    1986-01-01

    Blood flow within each of eight quadrants of the myocardium was measured in dogs using a cine-CT scanner and also with microspheres. Cine-CT flow measurements were made using a nonionic contrast agent and flow was calculated by a formula that used both the maximum iodine concentration and the peak delay time. Measurements were obtained at rest and during hyperperfusion induced by chromonar. Simultaneous cine-CT and microsphere measurements correlated (slope = 0.71 r = .8) over a range of 0.4-7.0 ml/min/g

  8. MUJERES DIRECTORAS DE CINE: UN RETO, UNA ESPERANZA

    OpenAIRE

    Trinidad Núñez Domínguez

    2010-01-01

    Este trabajo parte de considerar que analizar el cine con perspectiva de género tiene potencia educadora. El objetivo general del mismo es hacer un recorrido por los últimos veinte años de cine dirigido por mujeres (1989-2009). Dicho objetivo se concreta en dos: conocer quiénes son las mujeres que lideran el cine español tomando decisiones y rompiendo barreras (económicas, de gestión o de credibilidad) y conocer las características de sus trabajos. Proponemos un estudio centrado en la direcci...

  9. Mujeres directoras de cine: un reto, una esperanza

    OpenAIRE

    Núñez Domínguez, Trinidad

    2010-01-01

    Este trabajo parte de considerar que analizar el cine con perspectiva de género tiene potencia educadora. El objetivo general del mismo es hacer un recorrido por los últimos veinte años de cine dirigido por mujeres (1989-2009). Dicho objetivo se concreta en dos: conocer quiénes son las mujeres que lideran el cine español tomando decisiones y rompiendo barreras (económicas, de gestión o de credibilidad) y conocer las características de sus trabajos. Proponemos un estudio centrado e...

  10. Tumour auto-contouring on 2d cine MRI for locally advanced lung cancer: A comparative study.

    Science.gov (United States)

    Fast, Martin F; Eiben, Björn; Menten, Martin J; Wetscherek, Andreas; Hawkes, David J; McClelland, Jamie R; Oelfke, Uwe

    2017-12-01

    Radiotherapy guidance based on magnetic resonance imaging (MRI) is currently becoming a clinical reality. Fast 2d cine MRI sequences are expected to increase the precision of radiation delivery by facilitating tumour delineation during treatment. This study compares four auto-contouring algorithms for the task of delineating the primary tumour in six locally advanced (LA) lung cancer patients. Twenty-two cine MRI sequences were acquired using either a balanced steady-state free precession or a spoiled gradient echo imaging technique. Contours derived by the auto-contouring algorithms were compared against manual reference contours. A selection of eight image data sets was also used to assess the inter-observer delineation uncertainty. Algorithmically derived contours agreed well with the manual reference contours (median Dice similarity index: ⩾0.91). Multi-template matching and deformable image registration performed significantly better than feature-driven registration and the pulse-coupled neural network (PCNN). Neither MRI sequence nor image orientation was a conclusive predictor for algorithmic performance. Motion significantly degraded the performance of the PCNN. The inter-observer variability was of the same order of magnitude as the algorithmic performance. Auto-contouring of tumours on cine MRI is feasible in LA lung cancer patients. Despite large variations in implementation complexity, the different algorithms all have relatively similar performance. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  11. Raras y olvidadas: directoras de cine mudo

    Directory of Open Access Journals (Sweden)

    Rosa Mª Ballesteros García

    2015-10-01

    Full Text Available Este artículo sobre la dirección de mujeres durante la época del cine mudo (o silente, se resume como una época en que estas amazonas, sugerente apelativo ya utilizado por la filósofa Victoria Sendón, practicaron lo que alguien ha denominado “Heroísmo cotidiano”; un heroísmo que, por otra parte, se sigue practicando. Utilizando diversas fuentes hemos sacado a la luz más de un centenar de mujeres, profesionales del cine de la primera época que, saltándose las normas establecidas, no sólo prestaron su imagen como imán atractivo sino que, en línea con sus compañeros de profesión, se situaron tras las cámaras produciendo y dirigiendo sus propias películas durante aquellos oscuros y desconocidos años para el gran público. Con ello deseamos revivir algunos de los nombres de estas valientes mujeres, ninguneadas o ignoradas por la Historia.

  12. Cine transnacional, el sistema de festivales y la transformación digital

    Directory of Open Access Journals (Sweden)

    Thomas ELSAESSER

    2015-12-01

    Full Text Available Este artículo considera la idea del cine transnacional desde varias perspectivas distintas: primero, como un término que compite con otros -tales como “cine del mundo”, “cine independiente”, “cine con acento” o “cine periférico”-, que buscan también definir el cine no hollywoodiense. A pesar de ser en sí mismo un concepto problemático, el término “cine transnacional” es el que mejor representa la situación de la cinematografía actual bajo las condiciones que marca la globalización. En segundo lugar, el cine transnacional resalta los desafíos, contradicciones y posibilidades de su principal punto de encuentro e intercambio: el circuito de festivales internacionales de cine. En tercer lugar, el cine transnacional nos ayuda a entender los cambios producidos por el “giro digital” en el cine no hollywoodiense y, de este modo, redefine lo que queremos decir en la actualidad con “cine nacional”, “cine de autor” y “cine de pequeñas naciones”.

  13. Brote epidémico de tinea capitis por trichophyton tonsurans

    Directory of Open Access Journals (Sweden)

    Elizabeth Castañeda

    1981-06-01

    Full Text Available Se presenta un informe breve sobre un brote epidémico de Tinea Capitis ocurrido en un orfanato de Bogotá. En cuatro de los cinco casos se aisló como agente etiológico un dermatofito antropofílico: Trichophyton tonsurans. En otro caso se identificó T. mentagrophytes.

  14. El cine en el cine: Los abrazos rotos (Pedro Almodóvar, 2009

    Directory of Open Access Journals (Sweden)

    Pedro Poyato

    2012-10-01

    Full Text Available El cine en el cine, tema recurrente en la filmografía de Pedro Almodóvar, protagoniza también Los abrazos rotos, película que contiene en su interior otra titulada Chicas y maletas. Pero las imágenes de esta segunda película, trasunto de otra anterior del propio Almodóvar, Mujeres al borde un ataque de nervios, coexisten con las de un documental sobre su rodaje. El resultado es una proliferación de imágenes segundas que, incorporadas según una estructura en abismo, el filme va a conjugar de múltiples y variadas maneras. El presente trabajo trata de dar cuenta de la génesis, funcionamiento y declinación de estas imágenes segundas y de los sentidos que de ello emanan.

  15. Las razones de la noche: cine mexicano actual

    OpenAIRE

    Luna, Andrés de

    2004-01-01

    nulo El cine mexicano tiene una historia que comienza con la llegada de los enviados de los Lumiére en 1896. Luego llegó la revolución en 1910 y la cinematografía recuperá la imagen de los caudillos y de las batallas. Una vez que concluye el movimiento armado, se da un cine mudo cargado de evasiones, que imita al cine italiano. En 1936 se forma la industria del cine nacional gracias a la fórmula sugerida por el éxito comercial de Allá en el rancho grande. Después vendrá la época de oro del...

  16. Validation of Contrast Enhanced Cine Steady-State Free Precession and T2-Weigthed CMR for Assessment of Ischemic Myocardial Area- At-Risk

    DEFF Research Database (Denmark)

    Søvsø Szocska Hansen, Esben; Pedersen, Steen Fjord; Pedersen, Steen Bønløkke

    2017-01-01

    Measuring myocardial salvage is important to evaluate the possible cardioprotective effects of adjunctive cardioprotective intervention in patients with myocardial infarction undergoing primary percutaneous intervention. Contrast-enhanced steady-state free precession magnetic resonance imaging (CE-CINE......) has recently been used to quantify AAR and validated against myocardial perfusion SPECT. In this study we sought to determine how well T2-STIR and CE-CINE depicts AAR in an experimental porcine model of myocardial ischemia-reperfusion injury using histopathology as the reference for infarct size...

  17. Postprandial changes in secretory flow of pancreatic juice in the main pancreatic duct: evaluation with cine-dynamic MRCP with a spatially selective inversion-recovery (IR) pulse.

    Science.gov (United States)

    Yasokawa, Kazuya; Ito, Katsuyoshi; Tamada, Tsutomu; Yamamoto, Akira; Hayashida, Minoru; Torigoe, Teruyuki; Tanimoto, Daigo; Higaki, Atsushi; Noda, Yasufumi; Kido, Ayumu

    2016-12-01

    To evaluate the influence of oral ingestion on the secretory flow dynamics of physiological pancreatic juice within the main pancreatic duct in healthy subjects by using cine-dynamic MRCP with spatially-selective inversion-recovery (IR) pulse non-invasively. Thirty-eight healthy subjects were investigated. MRCP with spatially-selective IR pulse was repeated every 15 s for 5 min to acquire a total of 20 images (cine-dynamic MRCP). A set of 20 MRCP images was repeatedly obtained before and after liquid oral ingestion every 7 min (including 2-min interval) for 40 min (a total of seven sets). Secretion grade of pancreatic juice on cine-dynamic MRCP was compared before and after oral ingestion using the nonparametric Wilcoxon signed-rank test. Median secretion grades of pancreatic juice at 5 min (score = 2.15), 12 min (score = 1.95) and 19 min (score = 2.05) after ingestion were significantly higher than that before ingestion (score = 1.40) (P = 0.004, P = 0.032, P = 0.045, respectively). Secretion grade of pancreatic juice showed a maximum peak of 2.15 at 5 min after ingestion. Thereafter, the secretion grade of pancreatic juice tended to gradually decline. Non-invasive cine-dynamic MRCP using spatially-selective IR pulse showed potential for evaluating postprandial changes in the secretory flow dynamics of pancreatic juice as a physiological reaction. • Secretion grade of pancreatic juice at cine-dynamic MRCP after ingestion was evaluated. • Secretion grade was significantly increased within 19 min after liquid meal ingestion. • Secretion grade showed maximum peak of 2.15 at 5 min after ingestion. • Postprandial changes in pancreatic juice flow can be assessed by cine-dynamic MRCP.

  18. Assessment of left ventricular mechanical dyssynchrony in left bundle branch block canine model: Comparison between cine and tagged MRI.

    Science.gov (United States)

    Saporito, Salvatore; van Assen, Hans C; Houthuizen, Patrick; Aben, Jean-Paul M M; Strik, Marc; van Middendorp, Lars B; Prinzen, Frits W; Mischi, Massimo

    2016-10-01

    To compare cine and tagged magnetic resonance imaging (MRI) for left ventricular dyssynchrony assessment in left bundle branch block (LBBB), using the time-to-peak contraction timing, and a novel approach based on cross-correlation. We evaluated a canine model dataset (n = 10) before (pre-LBBB) and after induction of isolated LBBB (post-LBBB). Multislice short-axis tagged and cine MRI images were acquired using a 1.5 T scanner. We computed contraction time maps by cross-correlation, based on the timing of radial wall motion and of circumferential strain. Finally, we estimated dyssynchrony as the standard deviation of the contraction time over the different regions of the myocardium. Induction of LBBB resulted in a significant increase in dyssynchrony (cine: 13.0 ± 3.9 msec for pre-LBBB, and 26.4 ± 5.0 msec for post-LBBB, P = 0.005; tagged: 17.1 ± 5.0 msec at for pre-LBBB, and 27.9 ± 9.8 msec for post-LBBB, P = 0.007). Dyssynchrony assessed by cine and tagged MRI were in agreement (r = 0.73, P = 0.0003); differences were in the order of time difference between successive frames of 20 msec (bias: -2.9 msec; limit of agreement: 10.1 msec). Contraction time maps were derived; agreement was found in the contraction patterns derived from cine and tagged MRI (mean difference in contraction time per segment: 3.6 ± 13.7 msec). This study shows that the proposed method is able to quantify dyssynchrony after induced LBBB in an animal model. Cine-assessed dyssynchrony agreed with tagged-derived dyssynchrony, in terms of magnitude and spatial direction. J. MAGN. RESON. IMAGING 2016;44:956-963. © 2016 International Society for Magnetic Resonance in Medicine.

  19. Conventional and cine-MRI in patients with aneurysms of the abdominal aorta

    International Nuclear Information System (INIS)

    Gross-Fengels, W.; Friedmann, G.; Lemaitre, F.; Schmidt, R.; Lanfermann, H.; Erasmi, H.; Koeln Univ.

    1991-01-01

    We studied 40 patients with aneurysms of the abdominal aorta by MRI. These results were compared with those obtained by real-time sonography (n = 40), angiography (n = 32) and CT (n = 16). In 30 patients the imaging results were compared - as far as possible - with the operative findings. MRI proved more reliable, especially if compared with sonography, in evaluating renal or iliac artery involvement. Mural thrombi were detected more often (93%) by MRI than by CT (85%) or sonography (83%). Cine-MRI showed strong turbulences in 33%. Turbulences did not correlate with the size of the aneurysm. (orig.) [de