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Sample records for breast x-ray ct

  1. Ensuring convergence in total-variation-based reconstruction for accurate microcalcification imaging in breast X-ray CT

    CERN Document Server

    Jørgensen, Jakob H; Pan, Xiaochuan

    2011-01-01

    Breast X-ray CT imaging is being considered in screening as an extension to mammography. As a large fraction of the population will be exposed to radiation, low-dose imaging is essential. Iterative image reconstruction based on solving an optimization problem, such as Total-Variation minimization, shows potential for reconstruction from sparse-view data. For iterative methods it is important to ensure convergence to an accurate solution, since important image features, such as presence of microcalcifications indicating breast cancer, may not be visible in a non-converged reconstruction, and this can have clinical significance. To prevent excessively long computational times, which is a practical concern for the large image arrays in CT, it is desirable to keep the number of iterations low, while still ensuring a sufficiently accurate reconstruction for the specific imaging task. This motivates the study of accurate convergence criteria for iterative image reconstruction. In simulation studies with a realistic...

  2. The effect of characteristic x-rays on the spatial and spectral resolution of a CZT-based detector for breast CT

    Science.gov (United States)

    Glick, Stephen J.; Didier, Clay S.

    2011-03-01

    In an effort to improve the early stage detection and diagnosis of breast cancer, a number of research groups have been investigating the use of x-ray computerized tomography (CT) systems dedicated for use in imaging the breast. Preliminary results suggest that dedicated breast CT systems can provide improved visualization of 3D breast tissue as compared to conventional mammography. However, current breast CT prototypes that are being investigated have limitations resulting in less than desirable spatial resolution, lesion contrast, and signal-to-noise (SNR) ratio. Another option is a CT breast imaging system that uses a cadmium zinc telluride (CZT) based detector operating in a photon counting mode. This paper uses a Monte Carlo simulation to evaluate the effect of characteristic x-rays on spatial and spectral resolution for a CZT detector used for breast CT. It is concluded that using CZT of 500-750 μm would not cause significant differences in spatial or spectral resolution, nor in stopping power as compared to using CZT with thickness 2-3 mm.

  3. Reconstructing misaligned x-ray CT data

    Energy Technology Data Exchange (ETDEWEB)

    Divin, C. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-24

    Misalignment errors for x-ray computed tomography (CT) systems can manifest as artifacts and a loss of spatial and contrast resolution. To mitigate artifacts, significant effort is taken to determine the system geometry and minimizing any residual error in the system alignment. This project improved our ability to post-correct data which was acquired on a misaligned CT system.

  4. Attenuation correction of myocardial SPECT images with X-ray CT. Effects of registration errors between X-ray CT and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Yasuyuki; Murase, Kenya [Osaka Univ., Suita (Japan). Graduate School of Medicine; Higashino, Hiroshi [Ehime Prefectural Imabari Hospital (Japan); Mochizuki, Teruhito [Ehime Univ., Matsuyama (Japan). School of Medicine; Motomura, Nobutoku [Toshiba Corp., Otawara, Tochigi (Japan). Medical Engineering Lab.

    2002-09-01

    Attenuation correction with an X-ray CT image is a new method to correct attenuation on SPECT imaging, but the effect of the registration errors between CT and SPECT images is unclear. In this study, we investigated the effects of the registration errors on myocardial SPECT, analyzing data from a phantom and a human volunteer. Registerion (fusion) of the X-ray CT and SPECT images was done with standard packaged software in three dimensional fashion, by using linked transaxial, coronal and sagittal images. In the phantom study, and X-ray CT image was shifted 1 to 3 pixels on the x, y and z axes, and rotated 6 degrees clockwise. Attenuation correction maps generated from each misaligned X-ray CT image were used to reconstruct misaligned SPECT images of the phantom filled with {sup 201}Tl. In a human volunteer, X-ray CT was acquired in different conditions (during inspiration vs. expiration). CT values were transferred to an attenuation constant by using straight lines; an attenuation constant of 0/cm in the air (CT value=-1,000 HU) and that of 0.150/cm in water (CT value=0 HU). For comparison, attenuation correction with transmission CT (TCT) data and an external {gamma}-ray source ({sup 99m}Tc) was also applied to reconstruct SPECT images. Simulated breast attenuation with a breast attachment, and inferior wall attenuation were properly corrected by means of the attenuation correction map generated from X-ray CT. As pixel shift increased, deviation of the SPECT images increased in misaligned images in the phantom study. In the human study, SPECT images were affected by the scan conditions of the X-ray CT. Attenuation correction of myocardial SPECT with an X-ray CT image is a simple and potentially beneficial method for clinical use, but accurate registration of the X-ray CT to SPECT image is essential for satisfactory attenuation correction. (author)

  5. First X-ray fluorescence CT experimental results at the SSRF X-ray imaging beamline

    Institute of Scientific and Technical Information of China (English)

    DENG Biao; YANG Qun; XIE Hong-Lan; DU Guo-Hao; XIAO Wi-Qiao

    2011-01-01

    X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline (BL13W1) are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.

  6. Ensuring convergence in total-variation-based reconstruction for accurate microcalcification imaging in breast X-ray CT

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Heide; Sidky, Emil Y.; Pan, Xiaochuan

    2011-01-01

    , shows potential for reconstruction from sparse-view data. For iterative methods it is important to ensure convergence to an accurate solution, since important diagnostic image features, such as presence of microcalcifications indicating breast cancer, may not be visible in a non-converged reconstruction......, and this can have clinical significance. To prevent excessively long computational times, which is a practical concern for the large image arrays in CT, it is desirable to keep the number of iterations low, while still ensuring a sufficiently accurate reconstruction for the specific imaging task....... This motivates the study of accurate convergence criteria for iterative image reconstruction. In simulation studies with a realistic breast phantom with microcalcifications we investigate the issue of ensuring sufficiently converged solution for reliable reconstruction. Our results show that it can...

  7. Radiation Exposure in X-Ray and CT Examinations

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Radiation Dose in X-Ray and CT Exams What ... page for more information. top of page Measuring radiation dosage The scientific unit of measurement for radiation ...

  8. Dosimetry in x-ray-based breast imaging

    Science.gov (United States)

    Dance, David R.; Sechopoulos, Ioannis

    2016-10-01

    The estimation of the mean glandular dose to the breast (MGD) for x-ray based imaging modalities forms an essential part of quality control and is needed for risk estimation and for system design and optimisation. This review considers the development of methods for estimating the MGD for mammography, digital breast tomosynthesis (DBT) and dedicated breast CT (DBCT). Almost all of the methodology used employs Monte Carlo calculated conversion factors to relate the measurable quantity, generally the incident air kerma, to the MGD. After a review of the size and composition of the female breast, the various mathematical models used are discussed, with particular emphasis on models for mammography. These range from simple geometrical shapes, to the more recent complex models based on patient DBCT examinations. The possibility of patient-specific dose estimates is considered as well as special diagnostic views and the effect of breast implants. Calculations using the complex models show that the MGD for mammography is overestimated by about 30% when the simple models are used. The design and uses of breast-simulating test phantoms for measuring incident air kerma are outlined and comparisons made between patient and phantom-based dose estimates. The most widely used national and international dosimetry protocols for mammography are based on different simple geometrical models of the breast, and harmonisation of these protocols using more complex breast models is desirable.

  9. 3-D reconstruction and virtual ductoscopy of high-grade ductal carcinoma in situ of the breast with casting type calcifications using refraction-based X-ray CT.

    Science.gov (United States)

    Ichihara, Shu; Ando, Masami; Maksimenko, Anton; Yuasa, Tetsuya; Sugiyama, Hiroshi; Hashimoto, Eiko; Yamasaki, Katsuhito; Mori, Kensaku; Arai, Yoshinori; Endo, Tokiko

    2008-01-01

    Stereomicroscopic observations of thick sections, or three-dimensional (3-D) reconstructions from serial sections, have provided insights into histopathology. However, they generally require time-consuming and laborious procedures. Recently, we have developed a new algorithm for refraction-based X-ray computed tomography (CT). The aim of this study is to apply this emerging technology to visualize the 3-D structure of a high-grade ductal carcinomas in situ (DCIS) of the breast. The high-resolution two-dimensional images of the refraction-based CT were validated by comparing them with the sequential histological sections. Without adding any contrast medium, the new CT showed strong contrast and was able to depict the non-calcified fine structures such as duct walls and intraductal carcinoma itself, both of which were barely visible in a conventional absorption-based CT. 3-D reconstruction and virtual endoscopy revealed that the high-grade DCIS was located within the dichotomatous branches of the ducts. Multiple calcifications occurred in the necrotic core of the continuous DCIS, resulting in linear and branching (casting type) calcifications, a hallmark of high-grade DCIS on mammograms. In conclusion, refraction-based X-ray CT approaches the low-power light microscopic view of the histological sections. It provides high quality slice data for 3-D reconstruction and virtual ductosocpy.

  10. Retroflexed holoprosencephaly. X-ray CT findings and MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Nagano, N.; Ohno, K.; Masaoka, H.; Fukai, N.; Matsushima, Y.

    1987-02-01

    We report a case of holoprosencephaly with retroflexion and discuss the usefulness of X-ray CT in its diagnosis. A 2-month-old infant, admitted with severe hydrocephalus, underwent a ventriculo-peritoneal shunt. The brain was retroflexed with subdural fluid collection after the procedure. The pathological condition was, however, gradually improved by the use of an additional subduro-peritoneal shunt. The shift and distortion of the brain were observed by means of serial X-ray CT scans. MRI revealed the brain stuck mainly to the frontal bone, monoventricle, the so-called dorsal sac, and probably the pituitary gland, but not the fourth ventricle nor the aqueduct. Sagittal and coronal sections of MRI and axial sections of X-ray CT proved to be useful in the diagnosis and classification of the holoprosencephaly, even without other invasive diagnostic procedures.

  11. Research on Application Value of CT, Ultrasound and X-ray Mammography in The Diagnosis of Breast Carcinoma%CT、超声、X线钼靶在乳腺癌诊断中的应用价值研究

    Institute of Scientific and Technical Information of China (English)

    孟淑萍; 张正平; 王霈; 田兴仓; 朱力

    2014-01-01

    Objective To explore the application value of ultrasound, X-ray mammography and CT in the diagnosis of breast cancer. Methods A total of sixty patients with breast cancer admitted by this hospital from May, 2011 to May, 2014 were selected as research subjects, who were divided into the ultrasound group, X-ray mammography group, CT group, ultrasound combining X-ray mammography and CT group (combination group) according to different diagnostic methods, and positive detection rate and pathological structure of patients in two groups were compared. Results The positive detection rate between ultrasound examination, X-ray mammography examination and CT examination has no statistically significant,the p value was greater than 0.05. The positive detection rate of combined examination group was compared to that of patients in ultrasound examination group , X-ray mammography examination group, and the p value was less than 0.05,which means the difference was statistically significant. The comparison in pathological conditions of patients in three groups hit p>0.05, there was no statistically significant difference. Conclusions Ultrasound examination, X-ray mammography examination and CT examination are provided with advantages respectively, and the combination of such three methods increase the detection rate of breast cancer, and helpful to the early diagnosis and discovery of the breast cancer.%目的:探究超声、X线钼靶及CT在乳腺癌诊断中的应用价值。方法选取我院2011年5月至2014年5月60例乳腺癌患者作为研究对象,按照诊断方法的不同将其分为超声组、X线钼靶组、CT组、超声联合X线钼靶及CT组(联合组),观察各组患者阳性检出率。结果超声检查、X线钼靶检查、CT检查三组两两阳性检出率比较, p>0.05,差异无统计学意义;联合检查组分别与CT检查、超声检查、X线钼靶检查阳性检出率比较,p<0.05,差异具有统计学意义;四组

  12. Hard X-ray Microscopic Imaging Of Human Breast Tissues

    Science.gov (United States)

    Park, Sung H.; Kim, Hong T.; Kim, Jong K.; Jheon, Sang H.; Youn, Hwa S.

    2007-01-01

    X-ray microscopy with synchrotron radiation will be a useful tool for innovation of x-ray imaging in clinical and laboratory settings. It helps us observe detailed internal structure of material samples non-invasively in air. And, it also has the potential to solve some tough problems of conventional breast imaging if it could evaluate various conditions of breast tissue effectively. A new hard x-ray microscope with a spatial resolution better than 100 nm was installed at Pohang Light Source, a third generation synchrotron radiation facility in Pohang, Korea. The x-ray energy was set at 6.95 keV, and the x-ray beam was monochromatized by W/B4C monochromator. Condenser and objective zone plates were used as x-ray lenses. Zernike phase plate next to condenser zone plate was introduced for improved contrast imaging. The image of a sample was magnified 30 times by objective zone plate and 20 times by microscope objective, respectively. After additional 10 times digital magnification, the total magnifying power was up to 6000 times in the end. Phase contrast synchrotron images of 10-μm-thick female breast tissue of the normal, fibroadenoma, fibrocystic change and carcinoma cases were obtained. By phase contrast imaging, hard x-rays enable us to observe many structures of breast tissue without sample preparations such as staining or fixation.

  13. X-ray cone beam CT system calibration

    Science.gov (United States)

    Sire, Pascal; Rizo, Philippe; Martin, M.

    1993-12-01

    Recently x-ray cone beam computed tomography (CT) has become of interest for nondestructive testing (NDT) of advanced materials. Such a technique takes advantage of the cone beam geometry, to reduce the acquisition time and increase the resolution. Performances of CT systems rely mainly on geometric precision and measurement quality. Inaccurate geometry or incorrect data produce artifacts and blurring which limit the spatial resolution. A precise geometric calibration procedure is required and some corrections must be applied to the raw attenuation data in order to obtain accurate measurements. An x-ray cone beam CT system has been developed at the LETI. This machine was designed to control small parts limited to a few centimeters, with a high spatial resolution close to 30 microns. This paper introduces the machine setup and describes the calibration computing resources involved in the system. Then, we discuss the performances on experimental data.

  14. Proton-induced x-ray fluorescence CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bazalova-Carter, Magdalena, E-mail: bazalova@stanford.edu; Xing, Lei [Department of Radiation Oncology, Stanford University, Stanford, California 94305-5847 and Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo 060-8648 (Japan); Ahmad, Moiz [Department of Radiation Oncology, Stanford University, Stanford, California 94305-5847 (United States); Matsuura, Taeko; Takao, Seishin; Shirato, Hiroki; Umegaki, Kikuo [Department of Medical Physics, Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo 060-8648, Japan and Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo 060-8648 (Japan); Matsuo, Yuto [Department of Medical Physics, Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo 060-8648 (Japan); Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States)

    2015-02-15

    Purpose: To demonstrate the feasibility of proton-induced x-ray fluorescence CT (pXFCT) imaging of gold in a small animal sized object by means of experiments and Monte Carlo (MC) simulations. Methods: First, proton-induced gold x-ray fluorescence (pXRF) was measured as a function of gold concentration. Vials of 2.2 cm in diameter filled with 0%–5% Au solutions were irradiated with a 220 MeV proton beam and x-ray fluorescence induced by the interaction of protons, and Au was detected with a 3 × 3 mm{sup 2} CdTe detector placed at 90° with respect to the incident proton beam at a distance of 45 cm from the vials. Second, a 7-cm diameter water phantom containing three 2.2-diameter vials with 3%–5% Au solutions was imaged with a 7-mm FWHM 220 MeV proton beam in a first generation CT scanning geometry. X-rays scattered perpendicular to the incident proton beam were acquired with the CdTe detector placed at 45 cm from the phantom positioned on a translation/rotation stage. Twenty one translational steps spaced by 3 mm at each of 36 projection angles spaced by 10° were acquired, and pXFCT images of the phantom were reconstructed with filtered back projection. A simplified geometry of the experimental data acquisition setup was modeled with the MC TOPAS code, and simulation results were compared to the experimental data. Results: A linear relationship between gold pXRF and gold concentration was observed in both experimental and MC simulation data (R{sup 2} > 0.99). All Au vials were apparent in the experimental and simulated pXFCT images. Specifically, the 3% Au vial was detectable in the experimental [contrast-to-noise ratio (CNR) = 5.8] and simulated (CNR = 11.5) pXFCT image. Due to fluorescence x-ray attenuation in the higher concentration vials, the 4% and 5% Au contrast were underestimated by 10% and 15%, respectively, in both the experimental and simulated pXFCT images. Conclusions: Proton-induced x-ray fluorescence CT imaging of 3%–5% gold solutions in a

  15. Investigating the effect of characteristic x-rays in cadmium zinc telluride detectors under breast computerized tomography operating conditions.

    Science.gov (United States)

    Glick, Stephen J; Didier, Clay

    2013-10-14

    A number of research groups have been investigating the use of dedicated breast computerized tomography (CT). Preliminary results have been encouraging, suggesting an improved visualization of masses on breast CT as compared to conventional mammography. Nonetheless, there are many challenges to overcome before breast CT can become a routine clinical reality. One potential improvement over current breast CT prototypes would be the use of photon counting detectors with cadmium zinc telluride (CZT) (or CdTe) semiconductor material. These detectors can operate at room temperature and provide high detection efficiency and the capability of multi-energy imaging; however, one factor in particular that limits image quality is the emission of characteristic x-rays. In this study, the degradative effects of characteristic x-rays are examined when using a CZT detector under breast CT operating conditions. Monte Carlo simulation software was used to evaluate the effect of characteristic x-rays and the detector element size on spatial and spectral resolution for a CZT detector used under breast CT operating conditions. In particular, lower kVp spectra and thinner CZT thicknesses were studied than that typically used with CZT based conventional CT detectors. In addition, the effect of characteristic x-rays on the accuracy of material decomposition in spectral CT imaging was explored. It was observed that when imaging with 50-60 kVp spectra, the x-ray transmission through CZT was very low for all detector thicknesses studied (0.5-3.0 mm), thus retaining dose efficiency. As expected, characteristic x-ray escape from the detector element of x-ray interaction increased with decreasing detector element size, approaching a 50% escape fraction for a 100 μm size detector element. The detector point spread function was observed to have only minor degradation with detector element size greater than 200 μm and lower kV settings. Characteristic x-rays produced increasing distortion

  16. High resolution X-ray CT for advanced electronics packaging

    Science.gov (United States)

    Oppermann, M.; Zerna, T.

    2017-02-01

    Advanced electronics packaging is a challenge for non-destructive Testing (NDT). More, smaller and mostly hidden interconnects dominate modern electronics components and systems. To solve the demands of customers to get products with a high functionality by low volume, weight and price (e.g. mobile phones, personal medical monitoring systems) often the designers use System-in-Package solutions (SiP). The non-destructive testing of such devices is a big challenge. So our paper will impart fundamentals and applications for non-destructive evaluation of inner structures of electronics packaging for quality assurance and reliability investigations with a focus on X-ray methods, especially on high resolution X-ray computed tomography (CT).

  17. X-ray tube current modulation and patient doses in chest CT.

    Science.gov (United States)

    He, Wenjun; Huda, Walter; Magill, Dennise; Tavrides, Emily; Yao, Hai

    2011-01-01

    The aim of the study was to investigate how patient effective doses vary as a function of X-ray tube projection angle, as well as the patient long axis, and quantify how X-ray tube current modulation affects patient doses in chest CT examinations. Chest examinations were simulated for a gantry CT scanner geometry with projections acquired for a beam width of 4 cm. PCXMC 2.0.1 was used to calculate patient effective doses at 15° intervals around the patient's isocentre, and at nine locations along the patient long axis. Idealised tube current modulation schemes were modelled as a function of the X-ray tube angle and the patient long axis. Tube current modulations were characterised by the modulation amplitude R, which was allowed to vary between 1.5 and 5. Effective dose maxima occur for anteroposterior projections at the location of the (radiosensitive) breasts. The maximum to minimum ratio of effective doses as a function of the patient long axis was 4.9, and as a function of the X-ray tube angle was 2.1. Doubling the value of R reduces effective doses from longitudinal modulation alone by ∼4% and from angular modulation alone by ∼2%. In chest CT, tube current modulation schemes currently have longitudinal R values of ∼2.2, and angular R values that range between 1.5 and 3.4. Current X-ray tube current modulation schemes are expected to reduce patient effective doses in chest CT examinations by ∼10%, with longitudinal modulation accounting for two-thirds and angular modulation for the remaining one-third.

  18. Innovation and fusion of x-ray and optical tomography for mouse studies of breast cancer

    Science.gov (United States)

    Wang, Ge; Cong, Wenxiang; Yang, Qingsong; Pian, Qi; Zhu, Shouping; Liang, Jimin; Barroso, Margarida; Intes, Xavier

    2016-10-01

    For early detection and targeted therapy, receptor expression profiling is instrumental to classifying breast cancer into sub-groups. In particular, human epidermal growth factor receptor 2 (HER2) expression has been shown to have both prognostic and predictive values. Recently, an increasingly more complex view of HER2 in breast cancer has emerged from genome sequencing that highlights the role of inter- and intra-tumor heterogeneity in therapy resistance. Studies on such heterogeneity demand high-content, high-resolution functional and molecular imaging in vivo, which cannot be achieved using any single imaging tool. Clearly, there is a critical need to develop a multimodality approach for breast cancer imaging. Since 2006, grating-based x-ray imaging has been developed for much-improved x-ray images. In 2014, the demonstration of fluorescence molecular tomography (FMT) guided by x-ray grating-based micro-CT was reported with encouraging results and major drawbacks. In this paper, we propose to integrate grating-based x-ray tomography (GXT) and high-dimensional optical tomography (HOT) into the first-of-its-kind truly-fused GXT-HOT (pronounced as "Get Hot") system for imaging of breast tumor heterogeneity, HER2 expression and dimerization, and therapeutic response. The primary innovation lies in developing a brand-new high-content, high-throughput x-ray optical imager based on several contemporary techniques to have MRI-type soft tissue contrast, PET-like sensitivity and specificity, and micro-CT-equivalent resolution. This system consists of two orthogonal x-ray Talbot-Lau interferometric imaging chains and a hyperspectral time-resolved single-pixel optical imager. Both the system design and pilot results will be reported in this paper, along with relevant issues under further investigation.

  19. Optimization of propagation-based x-ray phase-contrast tomography for breast cancer imaging

    Science.gov (United States)

    Baran, P.; Pacile, S.; Nesterets, Y. I.; Mayo, S. C.; Dullin, C.; Dreossi, D.; Arfelli, F.; Thompson, D.; Lockie, D.; McCormack, M.; Taba, S. T.; Brun, F.; Pinamonti, M.; Nickson, C.; Hall, C.; Dimmock, M.; Zanconati, F.; Cholewa, M.; Quiney, H.; Brennan, P. C.; Tromba, G.; Gureyev, T. E.

    2017-03-01

    The aim of this study was to optimise the experimental protocol and data analysis for in-vivo breast cancer x-ray imaging. Results are presented of the experiment at the SYRMEP beamline of Elettra Synchrotron using the propagation-based phase-contrast mammographic tomography method, which incorporates not only absorption, but also x-ray phase information. In this study the images of breast tissue samples, of a size corresponding to a full human breast, with radiologically acceptable x-ray doses were obtained, and the degree of improvement of the image quality (from the diagnostic point of view) achievable using propagation-based phase-contrast image acquisition protocols with proper incorporation of x-ray phase retrieval into the reconstruction pipeline was investigated. Parameters such as the x-ray energy, sample-to-detector distance and data processing methods were tested, evaluated and optimized with respect to the estimated diagnostic value using a mastectomy sample with a malignant lesion. The results of quantitative evaluation of images were obtained by means of radiological assessment carried out by 13 experienced specialists. A comparative analysis was performed between the x-ray and the histological images of the specimen. The results of the analysis indicate that, within the investigated range of parameters, both the objective image quality characteristics and the subjective radiological scores of propagation-based phase-contrast images of breast tissues monotonically increase with the strength of phase contrast which in turn is directly proportional to the product of the radiation wavelength and the sample-to-detector distance. The outcomes of this study serve to define the practical imaging conditions and the CT reconstruction procedures appropriate for low-dose phase-contrast mammographic imaging of live patients at specially designed synchrotron beamlines.

  20. Development of X-ray CCD camera based X-ray micro-CT system

    Science.gov (United States)

    Sarkar, Partha S.; Ray, N. K.; Pal, Manoj K.; Baribaddala, Ravi; Agrawal, Ashish; Kashyap, Y.; Sinha, A.; Gadkari, S. C.

    2017-02-01

    Availability of microfocus X-ray sources and high resolution X-ray area detectors has made it possible for high resolution microtomography studies to be performed outside the purview of synchrotron. In this paper, we present the work towards the use of an external shutter on a high resolution microtomography system using X-ray CCD camera as a detector. During micro computed tomography experiments, the X-ray source is continuously ON and owing to the readout mechanism of the CCD detector electronics, the detector registers photons reaching it during the read-out period too. This introduces a shadow like pattern in the image known as smear whose direction is defined by the vertical shift register. To resolve this issue, the developed system has been incorporated with a synchronized shutter just in front of the X-ray source. This is positioned in the X-ray beam path during the image readout period and out of the beam path during the image acquisition period. This technique has resulted in improved data quality and hence the same is reflected in the reconstructed images.

  1. Development of X-ray CCD camera based X-ray micro-CT system.

    Science.gov (United States)

    Sarkar, Partha S; Ray, N K; Pal, Manoj K; Baribaddala, Ravi; Agrawal, Ashish; Kashyap, Y; Sinha, A; Gadkari, S C

    2017-02-01

    Availability of microfocus X-ray sources and high resolution X-ray area detectors has made it possible for high resolution microtomography studies to be performed outside the purview of synchrotron. In this paper, we present the work towards the use of an external shutter on a high resolution microtomography system using X-ray CCD camera as a detector. During micro computed tomography experiments, the X-ray source is continuously ON and owing to the readout mechanism of the CCD detector electronics, the detector registers photons reaching it during the read-out period too. This introduces a shadow like pattern in the image known as smear whose direction is defined by the vertical shift register. To resolve this issue, the developed system has been incorporated with a synchronized shutter just in front of the X-ray source. This is positioned in the X-ray beam path during the image readout period and out of the beam path during the image acquisition period. This technique has resulted in improved data quality and hence the same is reflected in the reconstructed images.

  2. Fast X-ray micro-CT for real-time 4D observation

    Energy Technology Data Exchange (ETDEWEB)

    Takano, H; Yoshida, K; Tsuji, T; Koyama, T; Tsusaka, Y; Kagoshima, Y, E-mail: htakano@sci.u-hyogo.ac.j [Graduate School of Material Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Ako, Hyogo 678-1297 (Japan)

    2009-09-01

    Fast X-ray computed tomography (CT) system with sub-second order measurement for single CT acquisition has been developed. The system, consisting of a high-speed sample rotation stage and a high-speed X-ray camera, is constructed at synchrotron radiation beamline in order to utilize fully intense X-rays. A time-resolving CT movie (i.e. 4D CT) can be available by operating the fast CT system continuously. Real-time observation of water absorbing process of super-absorbent polymer (SAP) has been successfully performed with the 4D CT operation.

  3. Magnetic resonance imaging of the central nervous system. Comparison with X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Kajima, Toshio; Kagawa, Yoshihiro; Katsuta, Shizutomo.

    1987-06-01

    Magnetic resonance imaging (MRI) and X-ray computed tomography (X-ray CT) have been performed in 169 consecutive patients with central nervous system diseases. The findings from the two methods were compared for the capacity to defect lesions. Magnetic resonance imaging was more sensitive than or equivalent to X-ray CT in detecting lesions - especially detecting. Arnold-Chiari malformation, syringomyelia, spinal cord injury, and pituitary adenoma - in 158 patients (94 %). In six patients (10 %), lesion detection was possible only by MRI. Magnetic resonance imaging was inferior to X-ray CT in 11 patients (7 %) in detecting calcified lesions, meningioma, and cavernous hemangioma. (Namekawa, K.).

  4. X-ray CT analysis of pore structure in sand

    Science.gov (United States)

    Mukunoki, Toshifumi; Miyata, Yoshihisa; Mikami, Kazuaki; Shiota, Erika

    2016-06-01

    The development of microfocused X-ray computed tomography (CT) devices enables digital imaging analysis at the pore scale. The applications of these devices are diverse in soil mechanics, geotechnical and geoenvironmental engineering, petroleum engineering, and agricultural engineering. In particular, the imaging of the pore space in porous media has contributed to numerical simulations for single-phase and multiphase flows or contaminant transport through the pore structure as three-dimensional image data. These obtained results are affected by the pore diameter; therefore, it is necessary to verify the image preprocessing for the image analysis and to validate the pore diameters obtained from the CT image data. Moreover, it is meaningful to produce the physical parameters in a representative element volume (REV) and significant to define the dimension of the REV. This paper describes the underlying method of image processing and analysis and discusses the physical properties of Toyoura sand for the verification of the image analysis based on the definition of the REV. On the basis of the obtained verification results, a pore-diameter analysis can be conducted and validated by a comparison with the experimental work and image analysis. The pore diameter is deduced from Young-Laplace's law and a water retention test for the drainage process. The results from previous study and perforated-pore diameter originally proposed in this study, called the voxel-percolation method (VPM), are compared in this paper. In addition, the limitations of the REV, the definition of the pore diameter, and the effectiveness of the VPM for an assessment of the pore diameter are discussed.

  5. The upper limits of the SNR in radiography and CT with polyenergetic x-rays.

    Science.gov (United States)

    Shikhaliev, Polad M

    2010-09-21

    The aim of the study is to determine the upper limits of the signal-to-noise ratio (SNR) in radiography and computed tomography (CT) with polyenergetic x-ray sources. In x-ray imaging, monoenergetic x-rays provide a higher SNR compared to polyenergetic x-rays. However, the SNR in polyenergetic x-ray imaging can be increased when a photon-counting detector is used and x-rays are optimally weighted according to their energies. For a particular contrast/background combination and at a fixed x-ray entrance skin exposure, the SNR in energy-weighting x-ray imaging depends on tube voltage and can be maximized by selecting the optimal tube voltage. The SNR in energy-weighted x-ray images acquired at this optimal tube voltage is the highest SNR that can be achieved with polyenergetic x-ray sources. The optimal tube voltages and the highest SNR were calculated and compared to the SNR of monoenergetic x-ray imaging. Monoenergetic, energy-weighting polyenergetic and energy-integrating polyenergetic x-ray imagings were simulated at a fixed entrance skin exposure of 20 mR. The tube voltages varied in the range of 30-140 kVp with 10 kV steps. Contrast elements of CaCO(3), iodine, adipose and tumor with thicknesses of 280 mg cm(-2), 15 mg cm(-2), 1 g cm(-2) and 1 g cm(-2), respectively, inserted in a soft tissue background with 10 cm and 20 cm thicknesses, were used. The energy weighting also improves the contrast-to-noise ratio (CNR) in CT when monoenergetic CT projections are optimally weighted prior to CT reconstruction (projection-based weighting). Alternatively, monoenergetic CT images are reconstructed, optimally weighted and composed to yield a final CT image (image-based weighting). Both projection-based and image-based weighting methods improve the CNR in CT. An analytical approach was used to determine which of these two weighting methods provides the upper limit of the CNR in CT. The energy-weighting method was generalized and expanded as a weighting method applicable

  6. X-ray scatter correction method for dedicated breast computed tomography: improvements and initial patient testing

    Science.gov (United States)

    Ramamurthy, Senthil; D'Orsi, Carl J.; Sechopoulos, Ioannis

    2016-02-01

    A previously proposed x-ray scatter correction method for dedicated breast computed tomography was further developed and implemented so as to allow for initial patient testing. The method involves the acquisition of a complete second set of breast CT projections covering 360° with a perforated tungsten plate in the path of the x-ray beam. To make patient testing feasible, a wirelessly controlled electronic positioner for the tungsten plate was designed and added to a breast CT system. Other improvements to the algorithm were implemented, including automated exclusion of non-valid primary estimate points and the use of a different approximation method to estimate the full scatter signal. To evaluate the effectiveness of the algorithm, evaluation of the resulting image quality was performed with a breast phantom and with nine patient images. The improvements in the algorithm resulted in the avoidance of introduction of artifacts, especially at the object borders, which was an issue in the previous implementation in some cases. Both contrast, in terms of signal difference and signal difference-to-noise ratio were improved with the proposed method, as opposed to with the correction algorithm incorporated in the system, which does not recover contrast. Patient image evaluation also showed enhanced contrast, better cupping correction, and more consistent voxel values for the different tissues. The algorithm also reduces artifacts present in reconstructions of non-regularly shaped breasts. With the implemented hardware and software improvements, the proposed method can be reliably used during patient breast CT imaging, resulting in improvement of image quality, no introduction of artifacts, and in some cases reduction of artifacts already present. The impact of the algorithm on actual clinical performance for detection, diagnosis and other clinical tasks in breast imaging remains to be evaluated.

  7. Quantitative breast tissue characterization using grating-based x-ray phase-contrast imaging

    Science.gov (United States)

    Willner, M.; Herzen, J.; Grandl, S.; Auweter, S.; Mayr, D.; Hipp, A.; Chabior, M.; Sarapata, A.; Achterhold, K.; Zanette, I.; Weitkamp, T.; Sztrókay, A.; Hellerhoff, K.; Reiser, M.; Pfeiffer, F.

    2014-04-01

    X-ray phase-contrast imaging has received growing interest in recent years due to its high capability in visualizing soft tissue. Breast imaging became the focus of particular attention as it is considered the most promising candidate for a first clinical application of this contrast modality. In this study, we investigate quantitative breast tissue characterization using grating-based phase-contrast computed tomography (CT) at conventional polychromatic x-ray sources. Different breast specimens have been scanned at a laboratory phase-contrast imaging setup and were correlated to histopathology. Ascertained tumor types include phylloides tumor, fibroadenoma and infiltrating lobular carcinoma. Identified tissue types comprising adipose, fibroglandular and tumor tissue have been analyzed in terms of phase-contrast Hounsfield units and are compared to high-quality, high-resolution data obtained with monochromatic synchrotron radiation, as well as calculated values based on tabulated tissue properties. The results give a good impression of the method’s prospects and limitations for potential tumor detection and the associated demands on such a phase-contrast breast CT system. Furthermore, the evaluated quantitative tissue values serve as a reference for simulations and the design of dedicated phantoms for phase-contrast mammography.

  8. Effect of oblique X-ray incidence in flat-panel computed tomography of the breast.

    Science.gov (United States)

    Badano, Aldo; Kyprianou, Iacovos S; Freed, Melanie; Jennings, Robert J; Sempau, Josep

    2009-05-01

    We quantify the variation in resolution due to anisotropy caused by oblique X-ray incidence in indirect flat-panel detectors for computed tomography breast imaging systems. We consider a geometry and detector type utilized in breast computed tomography (CT) systems currently being developed. Our methods rely on mantis, a combined X-ray, electron, and optical Monte Carlo transport open source code. The physics models are the most accurate available in general-purpose Monte Carlo packages in the diagnostic energy range. We consider maximum-obliquity angles of 10 ( degrees ) and 13 ( degrees ) at the centers of the 30 and 40 cm detector edges, respectively, and 16 ( degrees ) at the corner of the detector. Our results indicate that blur is asymmetric and that the resolution properties vary significantly with the angle (or location) of incidence. Our results suggest that the asymmetry can be as high as a factor of 2.6 between orthogonal directions. Anisotropy maps predicted by mantis provide an understanding of the effect that such variations have on the imaging system and allow more accurate modeling and optimization of breast CT systems. These maps of anisotropy across the detector could lead to improved reconstruction and help motivate physics-based strategies for computer detection of breast lesions.

  9. X-Ray Scatter Correction on Soft Tissue Images for Portable Cone Beam CT

    OpenAIRE

    Sorapong Aootaphao; Saowapak S. Thongvigitmanee; Jartuwat Rajruangrabin; Chalinee Thanasupsombat; Tanapon Srivongsa; Pairash Thajchayapong

    2016-01-01

    Soft tissue images from portable cone beam computed tomography (CBCT) scanners can be used for diagnosis and detection of tumor, cancer, intracerebral hemorrhage, and so forth. Due to large field of view, X-ray scattering which is the main cause of artifacts degrades image quality, such as cupping artifacts, CT number inaccuracy, and low contrast, especially on soft tissue images. In this work, we propose the X-ray scatter correction method for improving soft tissue images. The X-ray scatter ...

  10. X-Ray Methods to Estimate Breast Density Content in Breast Tissue

    Science.gov (United States)

    Maraghechi, Borna

    This work focuses on analyzing x-ray methods to estimate the fat and fibroglandular contents in breast biopsies and in breasts. The knowledge of fat in the biopsies could aid in their wide-angle x-ray scatter analyses. A higher mammographic density (fibrous content) in breasts is an indicator of higher cancer risk. Simulations for 5 mm thick breast biopsies composed of fibrous, cancer, and fat and for 4.2 cm thick breast fat/fibrous phantoms were done. Data from experimental studies using plastic biopsies were analyzed. The 5 mm diameter 5 mm thick plastic samples consisted of layers of polycarbonate (lexan), polymethyl methacrylate (PMMA-lucite) and polyethylene (polyet). In terms of the total linear attenuation coefficients, lexan ≡ fibrous, lucite ≡ cancer and polyet ≡ fat. The detectors were of two types, photon counting (CdTe) and energy integrating (CCD). For biopsies, three photon counting methods were performed to estimate the fat (polyet) using simulation and experimental data, respectively. The two basis function method that assumed the biopsies were composed of two materials, fat and a 50:50 mixture of fibrous (lexan) and cancer (lucite) appears to be the most promising method. Discrepancies were observed between the results obtained via simulation and experiment. Potential causes are the spectrum and the attenuation coefficient values used for simulations. An energy integrating method was compared to the two basis function method using experimental and simulation data. A slight advantage was observed for photon counting whereas both detectors gave similar results for the 4.2 cm thick breast phantom simulations. The percentage of fibrous within a 9 cm diameter circular phantom of fibrous/fat tissue was estimated via a fan beam geometry simulation. Both methods yielded good results. Computed tomography (CT) images of the circular phantom were obtained using both detector types. The radon transforms were estimated via four energy integrating

  11. 20 percent lower lung cancer mortality with low-dose CT vs chest X-ray

    Science.gov (United States)

    Scientists have found a 20 percent reduction in deaths from lung cancer among current or former heavy smokers who were screened with low-dose helical computed tomography (CT) versus those screened by chest X-ray.

  12. The X-ray CT lab and the research at the Institute of Geonics AS CR

    OpenAIRE

    2014-01-01

    In recent decades, non-destructive methods of materials analysis (Desrues 2006) have been used increasingly for the study of different kinds of materials. Especially, it concerns the method of the X-ray computed tomography (CT). This technique was invented in 1970's (Hounsfield 1972) and it quickly became an indispensable part of medicine. In the 1980's, this success in medicine encouraged the research and development of the X-ray CT applications in the field of materials engineering and cons...

  13. Simultaneous x-ray fluorescence and K-edge CT imaging with photon-counting detectors

    Science.gov (United States)

    Li, Liang; Li, Ruizhe; Zhang, Siyuan; Chen, Zhiqiang

    2016-10-01

    Rapid development of the X-ray phonon-counting detection technology brings tremendous research and application opportunities. In addition to improvements in conventional X-ray imaging performance such as radiation dose utilization and beam hardening correction, photon-counting detectors allows significantly more efficient X-ray fluorescence (XRF) and K-edge imaging, and promises a great potential of X-ray functional, cellular and molecular imaging. XRF is the characteristic emission of secondary X-ray photons from a material excited by initial X-rays. The phenomenon is widely used for chemical and elemental analysis. K-edge imaging identifies a material based on its chemically-specific absorption discontinuity over X-ray photon energy. In this paper, we try to combine XRF and K-edge signals from the contrast agents (e.g., iodine, gadolinium, gold nanoparticles) to simultaneously realize XFCT and K-edge CT imaging for superior image performance. As a prerequisite for this dual-modality imaging, the accurate energy calibration of multi-energy-bin photon-counting detectors is critically important. With the measured XRF data of different materials, we characterize the energy response function of a CZT detector for energy calibration and spectrum reconstruction, which can effectively improve the energy resolution and decrease the inconsistence of the photon counting detectors. Then, a simultaneous K-edge and X-ray fluorescence CT imaging (SKYFI) experimental setup is designed which includes a cone-beam X-ray tube, two separate photon counting detector arrays, a pin-hole collimator and a rotation stage. With a phantom containing gold nanoparticles the two types of XFCT and K-edge CT datasets are collected simultaneously. Then, XFCT and K-edge CT images are synergistically reconstructed in a same framework. Simulation results are presented and quantitative analyzed and compared with the separate XFCT and K-edge CT results.

  14. Novel detector design for reducing intercell x-ray cross-talk in the variable resolution x-ray CT scanner : A Monte Carlo study

    NARCIS (Netherlands)

    Arabi, Hosein; Asl, Ali Reza Kamali; Ay, Mohammad Reza; Zaidi, Habib

    2011-01-01

    Purpose: The variable resolution x-ray (VRX) CT scanner provides substantial improvement in the spatial resolution by matching the scanner's field of view (FOV) to the size of the object being imaged. Intercell x-ray cross-talk is one of the most important factors limiting the spatial resolution of

  15. Analytic Comparison between X-ray Fluorescence CT and K-edge CT

    CERN Document Server

    Feng, Peng; Cong, Wenxiang; Wei, Biao

    2013-01-01

    X-ray fluorescence computed tomography (XFCT) and K-edge computed tomography (CT) are two important modalities to quantify a distribution of gold nanoparticles (GNPs) in a small animal for preclinical studies. It is valuable to determine which modality is more efficient for a given application. In this paper, we report a theoretical analysis in terms of signal-to-noise ratio (SNR) for the two modalities, showing that there is a threshold for the GNPs concentration and XFCT has a better SNR than K-edge CT if GNPs concentration is less than this threshold. Numerical simulations are performed and two kinds of phantoms are used to represent multiple concentration levels and feature sizes. Experimental results illustrate that XFCT is superior to K-edge CT when contrast concentration is lower than 0.4% which coincides with the theoretical analysis.

  16. X-Ray Phase Imaging for Breast Cancer Detection

    Science.gov (United States)

    2011-09-01

    A. Yan, X. Wu, and H. Liu, Robustness of phase retrieval methods in x-ray phase contrast imaging: A comparison, Medical Physics 38: 5073-5080...2004. A new theory of phase-contrast x-ray imaging based on Wigner distributions. Medical Physics 31, 2378-2384. Wu X, Liu, H, Yan, A. 2005...Yan A., Wu X., Liu H. 2011. Robustness of phase retrieval methods in x-ray phase contrast imaging: A comparison, Medical Physics 38: 5073-5080

  17. Small-angle scattering computed tomography (SAS-CT) using a Talbot-Lau interferometerand a rotating anode x-ray tube:theory and experiments.

    Science.gov (United States)

    Chen, Guang-Hong; Bevins, Nicholas; Zambelli, Joseph; Qi, Zhihua

    2010-06-01

    X-ray differential phase contrast imaging methods, including projection imaging and the corresponding computed tomography (CT), have been implemented using a Talbot interferometer and either a synchrotron beam line or a low brilliance x-ray source generated by a stationary-anode x-ray tube. From small-angle scattering events which occur as an x-ray propagates through a medium, a signal intensity loss can be recorded and analyzed for an understanding of the micro-structures in an image object. This has been demonstrated using a Talbot-Lau interferometer and a stationary-anode x-ray tube. In this paper, theoretical principles and an experimental implementation of the corresponding CT imaging method are presented. First, a line integral is derived from analyzing the cross section of the small-angle scattering events. This method is referred to as small-angle scattering computed tomography (SAS-CT). Next, a Talbot-Lau interferometer and a rotating-anode x-ray tube were used to implement SAS-CT. A physical phantom and human breast tissue sample were used to demonstrate the reconstructed SAS-CT image volumes.

  18. 3D Prior Image Constrained Projection Completion for X-ray CT Metal Artifact Reduction

    NARCIS (Netherlands)

    Mehranian, Abolfazl; Ay, Mohammad Reza; Rahmim, Arman; Zaidi, Habib

    2013-01-01

    The presence of metallic implants in the body of patients undergoing X-ray computed tomography (CT) examinations often results insevere streaking artifacts that degrade image quality. In this work, we propose a new metal artifact reduction (MAR) algorithm for 2D fan-beam and 3D cone-beam CT based on

  19. Noninvasive thermometry with a clinical x-ray CT scanner

    Energy Technology Data Exchange (ETDEWEB)

    Fallone, B.G.; Moran, P.R.; Podgorsak, E.B.

    1982-09-01

    A CT scanner yields CT numbers which are proportional to the fractional difference in effective local electron density of the subject material with respect to that of calibration material. A homogeneous water-equivalent material is used as a calibration phantom under isothermal conditions. Any temperature variation (spatial or temporal) in the subject material subsequently scanned, will generate a CT-number shift in the CT image because of density changes due to thermal expansion. The potential use of the thermally generated CT-number shift in noninvasive thermometry during cancer hyperthermia was studied in vitro in samples of water and muscle tissue. The reproducibility of the area-averaged CT-number measurement on our EMI-7070 scanner was found to depend strongly on the time interval between successive counterclockwise scans and on the size of the region of interest used for area averaging. A linear relationship was found between the CT number and water density in the water temperature range from 10 to 55 /sup 0/C. In the hyperthermia temperature range (36--50 /sup 0/C), the relationship between the CT number and temperature itself is linear, with a CT-number thermal shift of about 0.4 and 0.45 HU//sup 0/C for water and muscle tissue, respectively. The achievable temperature discrimination is a fraction of /sup 0/C at spatial resolutions of the order of a centimeter.

  20. Breast density mapping based upon system calibration, x-ray techniques, and FFDM images

    Science.gov (United States)

    Chen, Biao; Smith, Andrew P.; Jing, Zhenxue; Wu, Tao

    2007-03-01

    Clinical studies have correlated a high breast density to a women's risk of breast cancer. A breast density measurement that can quantitatively depict the volume distribution and percentage of dense tissues in breasts would be very useful for risk factor assessment of breast cancer, and might be more predictive of risks than the common but subjective and coarse 4-point BIRADS scale. This paper proposes to use a neural-network mapping to compute the breast density information based upon system calibration data, x-ray techniques, and Full Field Digital Mammography (FFDM) images. The mapping consists of four modules, namely, system calibration, generator of beam quality, generator of normalized absorption, and a multi-layer feed-forward neural network. As the core of breast density mapping, the network accepts x-ray target/filter combination, normalized x-ray absorption, pixel-wise breast thickness map, and x-ray beam quality during image acquisition as input elements, and exports a pixel-wise breast density distribution and a single breast density percentage for the imaged breast. Training and testing data sets for the design and verification of the network were formulated from calibrated x-ray beam quality, imaging data with a step wedge phantom under a variety x-ray imaging techniques, and nominal breast densities of tissue equivalent materials. The network was trained using a Levenberg-Marquardt algorithm based back-propagation learning method. Various thickness and glandular density phantom studies were performed with clinical x-ray techniques. Preliminary results showed that the neural network mapping is promising in accurately computing glandular density distribution and breast density percentage.

  1. Medical X-Rays

    Science.gov (United States)

    ... Benefits The discovery of X-rays and the invention of CT represented major advances in medicine. X- ... in X-ray and CT Examinations — X-ray definition, dose measurement, safety precautions, risk, and consideration with ...

  2. Technical considerations for implementation of x-ray CT polymer gel dosimetry

    Science.gov (United States)

    Hilts, M.; Jirasek, A.; Duzenli, C.

    2005-04-01

    Gel dosimetry is the most promising 3D dosimetry technique in current radiation therapy practice. X-ray CT has been shown to be a feasible method of reading out polymer gel dosimeters and, with the high accessibility of CT scanners to cancer hospitals, presents an exciting possibility for clinical implementation of gel dosimetry. In this study we report on technical considerations for implementation of x-ray CT polymer gel dosimetry. Specifically phantom design, CT imaging methods, imaging time requirements and gel dose response are investigated. Where possible, recommendations are made for optimizing parameters to enhance system performance. The dose resolution achievable with an optimized system is calculated given voxel size and imaging time constraints. Results are compared with MRI and optical CT polymer gel dosimetry results available in the literature.

  3. Relaxed Linearized Algorithms for Faster X-Ray CT Image Reconstruction.

    Science.gov (United States)

    Nien, Hung; Fessler, Jeffrey A

    2016-04-01

    Statistical image reconstruction (SIR) methods are studied extensively for X-ray computed tomography (CT) due to the potential of acquiring CT scans with reduced X-ray dose while maintaining image quality. However, the longer reconstruction time of SIR methods hinders their use in X-ray CT in practice. To accelerate statistical methods, many optimization techniques have been investigated. Over-relaxation is a common technique to speed up convergence of iterative algorithms. For instance, using a relaxation parameter that is close to two in alternating direction method of multipliers (ADMM) has been shown to speed up convergence significantly. This paper proposes a relaxed linearized augmented Lagrangian (AL) method that shows theoretical faster convergence rate with over-relaxation and applies the proposed relaxed linearized AL method to X-ray CT image reconstruction problems. Experimental results with both simulated and real CT scan data show that the proposed relaxed algorithm (with ordered-subsets [OS] acceleration) is about twice as fast as the existing unrelaxed fast algorithms, with negligible computation and memory overhead.

  4. TU-EF-207-03: Advances in Stationary Breast Tomosynthesis Using Distributed X-Ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, O. [The University of North Carolina at Chapel Hill (United States)

    2015-06-15

    mode due to lower photon fluence per projection. This may require fast-frame acquisition and symmetric or asymmetric pixel binning in some systems. Recent studies investigated the performance of increased conversion layer thickness for contrast-enhanced imaging of the breast in dual-energy acquisition mode. In other direct conversion detectors operating in the avalanche mode, sensitivities close to the single photon response are also explored for mammography and breast tomosynthesis. The potential advantages and challenges of this approach are described. Dedicated breast CT brings x-ray imaging of the breast to true tomographic 3D imaging. It can eliminate the tissue superposition problem and does not require physical compression of the breast. Using cone beam geometry and a flat-panel detector, several hundred projections are acquired and reconstructed to near isotropic voxels. Multiplanar reconstruction facilitates viewing the breast volume in any desired orientation. Ongoing clinical studies, the current state-of-the art, and research to advance the technology are described. Learning Objectives: To understand the ongoing developments in x-ray imaging of the breast To understand the approaches and applications of spectral mammography To understand the potential advantages of distributed x-ray source arrays for digital breast tomosynthesis To understand the ongoing developments in detector technology for digital mammography and breast tomosynthesis To understand the current state-of-the-art for dedicated cone-beam breast CT and research to advance the technology. Research collaboration with Koning Corporation.

  5. The CT Scanner Facility at Stellenbosch University: An open access X-ray computed tomography laboratory

    Science.gov (United States)

    du Plessis, Anton; le Roux, Stephan Gerhard; Guelpa, Anina

    2016-10-01

    The Stellenbosch University CT Scanner Facility is an open access laboratory providing non-destructive X-ray computed tomography (CT) and a high performance image analysis services as part of the Central Analytical Facilities (CAF) of the university. Based in Stellenbosch, South Africa, this facility offers open access to the general user community, including local researchers, companies and also remote users (both local and international, via sample shipment and data transfer). The laboratory hosts two CT instruments, i.e. a micro-CT system, as well as a nano-CT system. A workstation-based Image Analysis Centre is equipped with numerous computers with data analysis software packages, which are to the disposal of the facility users, along with expert supervision, if required. All research disciplines are accommodated at the X-ray CT laboratory, provided that non-destructive analysis will be beneficial. During its first four years, the facility has accommodated more than 400 unique users (33 in 2012; 86 in 2013; 154 in 2014; 140 in 2015; 75 in first half of 2016), with diverse industrial and research applications using X-ray CT as means. This paper summarises the existence of the laboratory's first four years by way of selected examples, both from published and unpublished projects. In the process a detailed description of the capabilities and facilities available to users is presented.

  6. Region-Based 4D Tomographic Image Reconstruction: Application to Cardiac X-ray CT

    NARCIS (Netherlands)

    Eyndhoven, G. Van; Batenburg, K.J.; Sijbers, J.

    2015-01-01

    X-ray computed tomography (CT) is a powerful tool for noninvasive cardiac imaging. However, radiation dose is a major issue. In this paper, we propose an iterative reconstruction method that reduces the radiation dose without compromising image quality. This is achieved by exploiting prior knowledge

  7. Empirical average-case relation between undersampling and sparsity in X-ray CT

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Sauer; Sidky, Emil Y.; Hansen, Per Christian

    2015-01-01

    In X-ray computed tomography (CT) it is generally acknowledged that reconstruction methods exploiting image sparsity allow reconstruction from a significantly reduced number of projections. The use of such reconstruction methods is inspired by recent progress in compressed sensing (CS). However...

  8. The application of a novel detector for X-ray diffraction study of breast cancer

    OpenAIRE

    Zheng, Y.

    2016-01-01

    Current imaging methods - mammography, digital breast tomosynthesis, ultrasound and magnetic resonance images (MRI), fail to provide an accurate breast tumour size measurement. X-ray diffraction (XRD) can provide better contrast than mammography and digital breast tomosynthesis, better spatial resolution than ultrasound and is more cost effective than MRI. However, its use is limited by high radiation dose. Previous breast XRD research often fails to investigate samples with a realistic thick...

  9. Development of high-resolution x-ray CT system using parallel beam geometry

    Energy Technology Data Exchange (ETDEWEB)

    Yoneyama, Akio, E-mail: akio.yoneyama.bu@hitachi.com; Baba, Rika [Central Research Laboratory, Hitachi Ltd., Hatoyama, Saitama (Japan); Hyodo, Kazuyuki [Institute of Materials Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Takeda, Tohoru [School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa (Japan); Nakano, Haruhisa; Maki, Koutaro [Department of Orthodontics, School of Dentistry Showa University, Ota-ku, Tokyo (Japan); Sumitani, Kazushi; Hirai, Yasuharu [Kyushu Synchrotron Light Research Center, Tosu, Saga (Japan)

    2016-01-28

    For fine three-dimensional observations of large biomedical and organic material samples, we developed a high-resolution X-ray CT system. The system consists of a sample positioner, a 5-μm scintillator, microscopy lenses, and a water-cooled sCMOS detector. Parallel beam geometry was adopted to attain a field of view of a few mm square. A fine three-dimensional image of birch branch was obtained using a 9-keV X-ray at BL16XU of SPring-8 in Japan. The spatial resolution estimated from the line profile of a sectional image was about 3 μm.

  10. X-Ray Scatter Correction on Soft Tissue Images for Portable Cone Beam CT

    Directory of Open Access Journals (Sweden)

    Sorapong Aootaphao

    2016-01-01

    Full Text Available Soft tissue images from portable cone beam computed tomography (CBCT scanners can be used for diagnosis and detection of tumor, cancer, intracerebral hemorrhage, and so forth. Due to large field of view, X-ray scattering which is the main cause of artifacts degrades image quality, such as cupping artifacts, CT number inaccuracy, and low contrast, especially on soft tissue images. In this work, we propose the X-ray scatter correction method for improving soft tissue images. The X-ray scatter correction scheme to estimate X-ray scatter signals is based on the deconvolution technique using the maximum likelihood estimation maximization (MLEM method. The scatter kernels are obtained by simulating the PMMA sheet on the Monte Carlo simulation (MCS software. In the experiment, we used the QRM phantom to quantitatively compare with fan-beam CT (FBCT data in terms of CT number values, contrast to noise ratio, cupping artifacts, and low contrast detectability. Moreover, the PH3 angiography phantom was also used to mimic human soft tissues in the brain. The reconstructed images with our proposed scatter correction show significant improvement on image quality. Thus the proposed scatter correction technique has high potential to detect soft tissues in the brain.

  11. Combining ordered subsets and momentum for accelerated X-ray CT image reconstruction.

    Science.gov (United States)

    Kim, Donghwan; Ramani, Sathish; Fessler, Jeffrey A

    2015-01-01

    Statistical X-ray computed tomography (CT) reconstruction can improve image quality from reduced dose scans, but requires very long computation time. Ordered subsets (OS) methods have been widely used for research in X-ray CT statistical image reconstruction (and are used in clinical PET and SPECT reconstruction). In particular, OS methods based on separable quadratic surrogates (OS-SQS) are massively parallelizable and are well suited to modern computing architectures, but the number of iterations required for convergence should be reduced for better practical use. This paper introduces OS-SQS-momentum algorithms that combine Nesterov's momentum techniques with OS-SQS methods, greatly improving convergence speed in early iterations. If the number of subsets is too large, the OS-SQS-momentum methods can be unstable, so we propose diminishing step sizes that stabilize the method while preserving the very fast convergence behavior. Experiments with simulated and real 3D CT scan data illustrate the performance of the proposed algorithms.

  12. The Survey for Awareness of Radiation Dose of CT and General X-ray Examination

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Cheol; Cho, Han Byul [Dept. of Diagnostic Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Lim, Cheong Hwan; Jung, Hong Ryang; You, In Gyu; Yang, Oh Nam; Kim, Min Cheol [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of); Yoon, Joon [Dept. of Radiotechnolgy, Dongnam Health College, Suwon (Korea, Republic of)

    2012-03-15

    The goal of this study is to awaken about risk occurred by CT examination. For radio-technologists working at 'S medical center' located in Seoul, we investigated a recognition about dose and risk CT and normal X-ray examination according by working experience in hospital, experience about CT examination and radiation source. For subjects of investigation, radio-technologists working at 'S medical center' located in Seoul helped us. We collected 131 questionnaires for a test of hypothesis. Cronbach coefficients of questionnaires were 0.825988 and 0.767161 and a rejection rate of p-value was below 0.05. SAS 9.1(SAS Institute Inc., Cary, NC, USA.) statistic package was used for hypothesis test. We used Mann-Whitney test, Kruskai-Wallis test, Two sample T-test, Two sample T-test with Bonferroni's Correction and One-way ANOVA methods. P-values of hypothesis about dose of CT and normal X-ray examination were 0.2291-0.9663. p-values of hypothesis about risk were 0.1924-1.0000. All of hypothesis is over rejection rate(<0.05). This study shows that radio-technologists of S medical center recognized that CT has higher dose and risk than general X-ray examination.

  13. X-ray fluorescence and energy dispersive x-ray diffraction for the quantification of elemental concentrations in breast tissue.

    Science.gov (United States)

    Geraki, K; Farquharson, M J; Bradley, D A

    2004-01-07

    This paper presents improvements on a previously reported method for the measurement of elements in breast tissue specimens (Geraki et al 2002 Phys. Med. Biol. 47 2327-39). A synchrotron-based system was used for the detection of the x-ray fluorescence (XRF) emitted from iron, copper, zinc and potassium in breast tissue specimens, healthy and cancerous. Calibration models resulting from the irradiation of standard aqueous solutions were used for the quantification of the elements. The present developments concentrate on increasing the convergence between the tissue samples and the calibration models, therefore improving accuracy. For this purpose the composition of the samples in terms of adipose and fibrous tissue was evaluated, using an energy dispersive x-ray diffraction (EDXRD) system. The relationships between the attenuation and scatter properties of the two tissue components and water were determined through Monte Carlo simulations. The results from the simulations and the EDXRD measurements allowed the XRF data from each specimen to be corrected according to its composition. The statistical analysis of the elemental concentrations of the different groups of specimens reveals that all four elements are found in elevated levels in the tumour specimens. The increase is less pronounced for iron and copper and most for potassium and zinc. Other observed features include the substantial degree of inhomogeneity of elemental distributions within the volume of the specimens, varying between 4% and 36% of the mean, depending on the element and the type of the sample. The accuracy of the technique, based on the measurement of a standard reference material, proved to be between 3% and 22% depending on the element, which presents only a marginal improvement (1%-3%) compared to the accuracy of the previously reported results. The measurement precision was between 1% and 9% while the calculated uncertainties on the final elemental concentrations ranged between 10% and 16%.

  14. A preliminary study of breast cancer diagnosis using laboratory based small angle x-ray scattering

    Science.gov (United States)

    Round, A. R.; Wilkinson, S. J.; Hall, C. J.; Rogers, K. D.; Glatter, O.; Wess, T.; Ellis, I. O.

    2005-09-01

    Breast tissue collected from tumour samples and normal tissue from bi-lateral mastectomy procedures were examined using small angle x-ray scattering. Previous work has indicated that breast tissue disease diagnosis could be performed using small angle x-ray scattering (SAXS) from a synchrotron radiation source. The technique would be more useful to health services if it could be made to work using a conventional x-ray source. Consistent and reliable differences in x-ray scatter distributions were observed between samples from normal and tumour tissue samples using the laboratory based 'SAXSess' system. Albeit from a small number of samples, a sensitivity of 100% was obtained. This result encourages us to pursue the implementation of SAXS as a laboratory based diagnosis technique.

  15. A preliminary study of breast cancer diagnosis using laboratory based small angle x-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Round, A R [Daresbury Laboratories, Warrington, WA4 4AD (United Kingdom); Wilkinson, S J [Daresbury Laboratories, Warrington, WA4 4AD (United Kingdom); Hall, C J [Daresbury Laboratories, Warrington, WA4 4AD (United Kingdom); Rogers, K D [Department of Materials and Medical Sciences, Cranfield University, Swindon, SN6 8LA (United Kingdom); Glatter, O [Department of Chemistry, University of Graz (Austria); Wess, T [School of Optometry and Vision Sciences, Cardiff University, Cardiff CF10 3NB, Wales (United Kingdom); Ellis, I O [Nottingham City Hospital, Nottingham (United Kingdom)

    2005-09-07

    Breast tissue collected from tumour samples and normal tissue from bi-lateral mastectomy procedures were examined using small angle x-ray scattering. Previous work has indicated that breast tissue disease diagnosis could be performed using small angle x-ray scattering (SAXS) from a synchrotron radiation source. The technique would be more useful to health services if it could be made to work using a conventional x-ray source. Consistent and reliable differences in x-ray scatter distributions were observed between samples from normal and tumour tissue samples using the laboratory based 'SAXSess' system. Albeit from a small number of samples, a sensitivity of 100% was obtained. This result encourages us to pursue the implementation of SAXS as a laboratory based diagnosis technique.

  16. Thin soil layer of green roof systems studied by X-Ray CT

    Science.gov (United States)

    Šácha, Jan; Jelínková, Vladimíra; Dohnal, Michal

    2016-04-01

    The popular non-invasive visualization technique of X-ray computed tomography (CT) has been used for 3D examination of thin soil layer of vegetated roof systems. The two categories of anthropogenic soils, usually used for green roof systems, were scanned during the first months after green roof system construction. First was represented by stripped topsoil with admixed crushed bricks and was well graded in terms of particle size distribution. The other category represented a commercial lightweight technogenic substrate. The undisturbed soil samples of total volume of 62.8 ccm were studied be means of X-ray Computed Tomography using X-ray Inspection System GE Phoenix Nanomex 180T with resulting spatial resolution about 57 μm in all directions. For both soil categories visible macroporosity, connectivity (described by the Euler characteristic), dimensionless connectivity and critical cross section of pore network were determined. Moreover, the temporal structural changes of studied soils were discussed together with heat and water regime of the green roof system. The analysis of CT images of anthropogenic soils was problematic due to the different X-ray attenuation of individual constituents. The correct determination of the threshold image intensity differentiating the soil constituents from the air phase had substantial importance for soil pore network analyses. However, X-ray CT derived macroporosity profiles reveal significant temporal changes notably in the soil comprised the stripped topsoil with admixed crushed bricks. The results implies that the technogenic substrate is structurally more stable over time compared to the stripped topsoil. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech Science Foundation under project number 14-10455P.

  17. Reproducibility of X-rays and CT arthrography in SLAC, SNAC, SCAC wrists.

    Science.gov (United States)

    Belhaouane, R; Lebeau, N; Maes-Clavier, C; Hustin, C; Krief, E; Bonnaire, B; Warin, M; Rotari, V; David, E

    2016-12-01

    The purpose of this study was to assess the inter-observer and intra-observer reproducibility of the interpretation of CT arthrography and plain X-rays for scapholunate advanced collapse (SLAC), scaphoid non-union advanced collapse (SNAC) and scaphoid chondrocalcinosis advanced collapse (SCAC) wrist conditions, as well as the clinical relevance of these imaging modalities. The CT and X-rays images were reviewed twice in a blinded and randomized manner by two experienced orthopedic surgeons specialized in hand surgery, two orthopedic surgery residents and two experienced radiologists specialized in bone and joint imaging. Cohen's kappa and Fleiss' kappa coefficients were used to analyze the reproducibility of interpretation of the radiological examinations. With CT arthrography, the overall diagnosis was often a problem, in terms of both inter- or intra-observer reproducibility. The assessment of the joint line appeared to be fairly reproducible for each observer but was poorly reproducible between different observers. Plain X-rays are not sufficient to assess cartilage quality in degenerative wrist disease. CT arthrography is a reliable examination, but its interpretation is not always standardized. Diagnostic arthroscopy may be justified in doubtful cases.

  18. Synchrotron X-ray CT of rose peduncles. Evaluation of tissue damage by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Herppich, Werner B. [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V., Potsdam (Germany). Abt. Technik im Gartenbau; Matsushima, Uzuki [Iwate Univ., Morioka (Japan). Faculty of Agriculture; Graf, Wolfgang [Association for Technology and Structures in Agriculture (KTBL), Darmstadt (Germany); Zabler, Simon [Fraunhofer-Institut fuer Integrierte Schaltungen (IIS), Wuerzburg (Germany). Project group NanoCT Systems (NCTS); Dawson, Martin [Salford Univ., Greater Manchester (United Kingdom); Choinka, Gerard; Manke, Ingo [Helmholtz Center Berlin for Materials and Energy (HZB), Berlin (Germany)

    2015-02-01

    ''Bent-neck'' syndrome, an important postharvest problem of cut roses, is probably caused by water supply limitations and/or the structural weakness of vascular bundles of the peduncle tissue. For this reason, advanced knowledge about the microstructures of rose peduncles and their cultivar specific variations may lead to a better understanding of the underlying mechanisms. Synchrotron X-ray computed tomography (SXCT), especially phase-based CT, is a highly suitable technique to nondestructively investigate plants' micro anatomy. SXCT with monochromatic X-ray beams of 30, 40 and 50 keV photon energy was used to evaluate the three-dimensional inner structures of the peduncles of 3 rose cultivars that differ greatly in their bent-neck susceptibility. Results indicated that this technique achieves sufficiently high spatial resolution to investigate complex tissues. However, further investigations with chlorophyll fluorescence analysis (CFA) and optical microscope imagery reveal different kinds of heavy damage of the irradiated regions induced by synchrotron X-rays; in a cultivar-specific manner, partial destruction of cell walls occurred a few hours after X-ray irradiation. Furthermore, a delayed inhibition of photosynthesis accompanied by the degradation of chlorophyll was obvious from CFA within hours and days after the end of CT measurements. Although SXCT is certainly well suited for three-dimensional anatomical analysis of rose peduncles, the applied technique is not nondestructive.

  19. Application of small-angle X-ray scattering for differentiation among breast tumors

    Directory of Open Access Journals (Sweden)

    Changizi V

    2008-01-01

    Full Text Available Small-angle X-ray scattering (SAXS is an X-ray diffraction-based technique where a narrow collimated beam of X-rays is focused onto a sample and the scattered X-rays recorded by a detector. The pattern of the scattered X-rays carries information on the molecular structure of the material. As breast cancer is the most widespread cancer in women and differentiation among its tumors is important, this project compared the results of coherent X-ray scattering measurements obtained from benign and malignant breast tissues. The energy-dispersive method with a setup including X-ray tube, primary collimator, sample holder, secondary collimator and high-purity germanium (HpGe detector was used. One hundred thirty-one breast-tissue samples, including normal, fibrocystic changes and carcinoma, were studied at the 6° scattering angle. Diffraction profiles (corrected scattered intensity versus momentum transfer of normal, fibrocystic changes and carcinoma were obtained. These profiles showed a few peak positions for adipose (1.15 ± 0.06 nm -1 , mixed normal (1.15 ± 0.06 nm -1 and 1.4 ± 0.04 nm -1 , fibrocystic changes (1.46 ± 0.05 nm -1 and 1.74 ± 0.04 nm -1 and carcinoma (1.55 ± 0.04 nm -1 , 1.73 ± 0.06 nm -1 , 1.85 ± 0.05 nm -1 . We were able to differentiate between normal, fibrocystic changes (benign and carcinoma (malignant breast tissues by SAXS. However, we were unable to differentiate between different types of carcinoma.

  20. Three dimensional analysis of coelacanth body structure by computer graphics and X-ray CT images

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Naoki (Jikei Univ., Tokyo (Japan). School of Medicine); Hamada, Takashi

    1990-06-01

    Three dimensional imaging processes were applied for the structural and functional analyses of the modern coelacanth (Latimeria chalumnae). Visualization of the obtained images is performed with computer graphics on the basis of serial images by an X-ray CT scanning method. Reconstruction of three dimensional images of the body structure of coelacanth using the volume rendering and surface rendering methods provides us various information about external and internal shapes of this exquisite fish. (author).

  1. Evaluation of x-ray diffraction enhanced imaging in the diagnosis of breast cancer.

    Science.gov (United States)

    Liu, Chenglin; Yan, Xiaohui; Zhang, Xinyi; Yang, Wentao; Peng, Weijun; Shi, Daren; Zhu, Peiping; Huang, Wanxia; Yuan, Qingxi

    2007-01-21

    The significance of the x-ray diffraction enhanced imaging (DEI) technique in the diagnosis of breast cancer and its feasibility in clinical medical imaging are evaluated. Different massive specimens including normal breast tissues, benign breast tumour tissues and malignant breast tumour tissues are imaged with the DEI method. The images are recorded respectively by CCD or x-ray film at different positions of the rocking curve and processed with a pixel-by-pixel algorithm. The characteristics of the DEI images about the normal and diseased tissues are compared. The rocking curves of a double-crystal diffractometer with various tissues are also studied. The differences in DEI images and their rocking curves are evaluated for early diagnosis of breast cancers.

  2. Fatigue damage observed non-destructively in fibre composite coupon test specimens by X-ray CT

    DEFF Research Database (Denmark)

    Jespersen, Kristine Munk; Mikkelsen, Lars Pilgaard

    2016-01-01

    This study presents a method for monitoring the 3D fatigue damage progression on a micro-structural level in a glass fibre/polymer coupon test specimen by means of laboratory X-ray Computed Tomography (CT). A modified mount and holder made for the standard test samples to fit into the X-ray CT...... scanner along with a tension clamp solution is presented. Initially, the same location of the test specimen is inspected by ex-situ X-ray CT during the fatigue loading history, which shows the damage progression on a micro-structural level. The openings of individual uni-directional (UD) fibre fractures...

  3. CT dual-energy decomposition into x-ray signatures ρe and Ze

    Science.gov (United States)

    Martz, Harry E.; Seetho, Issac M.; Champley, Kyle E.; Smith, Jerel A.; Azevedo, Stephen G.

    2016-05-01

    In a recent journal article [IEEE Trans. Nuc. Sci., 63(1), 341-350, 2016], we introduced a novel method that decomposes dual-energy X-ray CT (DECT) data into electron density (ρe) and a new effective-atomic-number called Ze in pursuit of system-independent characterization of materials. The Ze of a material, unlike the traditional Zeff, is defined relative to the actual X-ray absorption properties of the constituent atoms in the material, which are based on published X-ray cross sections. Our DECT method, called SIRZ (System-Independent ρe, Ze), uses a set of well-known reference materials and an understanding of the system spectral response to produce accurate and precise estimates of the X-ray-relevant basis variables (ρe, Ze) regardless of scanner or spectra in diagnostic energy ranges (30 to 200 keV). Potentially, SIRZ can account for and correct spectral changes in a scanner over time and, because the system spectral response is included in the technique, additional beam-hardening correction is not needed. Results show accuracy (<3%) and precision (<2%) values that are much better than prior methods on a wide range of spectra. In this paper, we will describe how to convert DECT system output into (ρe, Ze) features and we present our latest SIRZ results compared with ground truth for a set of materials.

  4. Reference factor F{sub (CT)Q} and X ray tube ionization yield R{sub (TUBE)Q}

    Energy Technology Data Exchange (ETDEWEB)

    Quaresma, D.S. [Observatorio Nacional, Rio de Janeiro, RJ (Brazil); Cardoso, R.S.; Peixoto, J.G.P., E-mail: dansq@on.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The operational facility procedures in diagnostic radiology standardization and calibration, through the relation between the X ray tube current and the ionization chamber current in a radiation quality Q, shown the reference factor F{sub (CT)Q} as the reality estimate to the X ray tube ionization yield, R{sub (TUBE)Q} . (author)

  5. Diagnostic modalities x-ray and CT chest differ in the management of thoracic injury

    Directory of Open Access Journals (Sweden)

    D Chapagain

    2015-06-01

    Full Text Available Objective: To observe difference in the management of blunt trauma to the chest on the basis of conventional xray and computerised tomography of the chest. Methods: This prospective study was conducted between December 2011 to October 2012 in COMS in Bharatpur,a tertiary referral centre in central Nepal . Clinically stable thoracic injury patients were first evaluated with chest x-ray and the management on this basis was recorded. The findings of the CT chest were assessed and the type of management on the basis of CT was also recorded. Outcome was assessed in terms of mortality, morbidity, hospital and ICU stay with respect to the management on the basis of chest x-ray and CT scan. Results: Of the 129 patients, 74.4% were male and 25.6% were female with the patients ranging in age from 7 to 87 years (mean = 40.41 years. The most common mechanism of trauma to the chest was as a result of a motor vehicle accident (69.8%, followed by fall injury (20.2%. X-ray chest diagnosed rib fracture in 62%, haemothorax in 37%, pneumothorax in 27%, lung contusion in 10% and haemopneumothorax in 21% patients. Similarly CT chest diagnosed rib fracture in 86%, haemothorax in 54%, pneumothorax in 36%, lung contusion in 30% and haemopneumothorax in 30% patients. Mean hospital stay was 9.5 days in the group of patients having management on the basis of x-ray chest relative to mean stay of 10.2 days in the CT- chest group. In the management on the basis of xray group, there was a mean ICU stay of 2.8days compared to mean stays of 3.2 days in CT chest group. Conclusion: Though CT scan of the chest is more informative and differs the management of the blunt chest trauma, one should not forget to advise the cost effective, easily available and initial guiding agent, xray chest for early management of the chest injury patient. DOI: http://dx.doi.org/10.3126/jcmsn.v10i1.12764 Journal of College of Medical Sciences-Nepal, 2014, Vol.10(1; 22-31

  6. Model-based x-ray energy spectrum estimation algorithm from CT scanning data with spectrum filter

    Science.gov (United States)

    Li, Lei; Wang, Lin-Yuan; Yan, Bin

    2016-10-01

    With the development of technology, the traditional X-ray CT can't meet the modern medical and industry needs for component distinguish and identification. This is due to the inconsistency of X-ray imaging system and reconstruction algorithm. In the current CT systems, X-ray spectrum produced by X-ray source is continuous in energy range determined by tube voltage and energy filter, and the attenuation coefficient of object is varied with the X-ray energy. So the distribution of X-ray energy spectrum plays an important role for beam-hardening correction, dual energy CT image reconstruction or dose calculation. However, due to high ill-condition and ill-posed feature of system equations of transmission measurement data, statistical fluctuations of X ray quantum and noise pollution, it is very hard to get stable and accurate spectrum estimation using existing methods. In this paper, a model-based X-ray energy spectrum estimation method from CT scanning data with energy spectrum filter is proposed. First, transmission measurement data were accurately acquired by CT scan and measurement using phantoms with different energy spectrum filter. Second, a physical meaningful X-ray tube spectrum model was established with weighted gaussian functions and priori information such as continuity of bremsstrahlung and specificity of characteristic emission and estimation information of average attenuation coefficient. The parameter in model was optimized to get the best estimation result for filtered spectrum. Finally, the original energy spectrum was reconstructed from filtered spectrum estimation with filter priori information. Experimental results demonstrate that the stability and accuracy of X ray energy spectrum estimation using the proposed method are improved significantly.

  7. Visual C++ Implementation of Sinogram-based Adaptive Iterative Reconstruction for Sparse View X-Ray CT

    CERN Document Server

    Trinca, D; Wang, Y; Mamyrbayev, T; Libin, E

    2016-01-01

    With the availability of more powerful computing processors, iterative reconstruction algorithms have recently been successfully implemented as an approach to achieving significant dose reduction in X-ray CT. In this report, we describe our proposal of an adaptive iterative reconstruction algorithm for X-ray CT, that is shown to provide results comparable to those obtained by proprietary algorithms, both in terms of reconstruction accuracy and execution time. Implementation code in the C language is provided, along with example of user interface.

  8. Development of a fast multi-line x-ray CT detector for NDT

    Science.gov (United States)

    Hofmann, T.; Nachtrab, F.; Schlechter, T.; Neubauer, H.; Mühlbauer, J.; Schröpfer, S.; Ernst, J.; Firsching, M.; Schweiger, T.; Oberst, M.; Meyer, A.; Uhlmann, N.

    2015-04-01

    Typical X-ray detectors for non-destructive testing (NDT) are line detectors or area detectors, like e.g. flat panel detectors. Multi-line detectors are currently only available in medical Computed Tomography (CT) scanners. Compared to flat panel detectors, line and multi-line detectors can achieve much higher frame rates. This allows time-resolved 3D CT scans of an object under investigation. Also, an improved image quality can be achieved due to reduced scattered radiation from object and detector themselves. Another benefit of line and multi-line detectors is that very wide detectors can be assembled easily, while flat panel detectors are usually limited to an imaging field with a size of approx. 40 × 40 cm2 at maximum. The big disadvantage of line detectors is the limited number of object slices that can be scanned simultaneously. This leads to long scan times for large objects. Volume scans with a multi-line detector are much faster, but with almost similar image quality. Due to the promising properties of multi-line detectors their application outside of medical CT would also be very interesting for NDT. However, medical CT multi-line detectors are optimized for the scanning of human bodies. Many non-medical applications require higher spatial resolutions and/or higher X-ray energies. For those non-medical applications we are developing a fast multi-line X-ray detector.In the scope of this work, we present the current state of the development of the novel detector, which includes several outstanding properties like an adjustable curved design for variable focus-detector-distances, conserving nearly uniform perpendicular irradiation over the entire detector width. Basis of the detector is a specifically designed, radiation hard CMOS imaging sensor with a pixel pitch of 200 μ m. Each pixel has an automatic in-pixel gain adjustment, which allows for both: a very high sensitivity and a wide dynamic range. The final detector is planned to have 256 lines of

  9. Study on Compression Induced Contrast in X-ray Mammograms Using Breast Mimicking Phantoms

    Directory of Open Access Journals (Sweden)

    A. B. M. Aowlad Hossain

    2015-09-01

    Full Text Available X-ray mammography is commonly used to scan cancer or tumors in breast using low dose x-rays. But mammograms suffer from low contrast problem. The breast is compressed in mammography to reduce x-ray scattering effects. As tumors are stiffer than normal tissues, they undergo smaller deformation under compression. Therefore, image intensity at tumor region may change less than the background tissues. In this study, we try to find out compression induced contrast from multiple mammographic images of tumorous breast phantoms taken with different compressions. This is an extended work of our previous simulation study with experiment and more analysis. We have used FEM models for synthetic phantom and constructed a phantom using agar and n-propanol for simulation and experiment. The x-ray images of deformed phantoms have been obtained under three compression steps and a non-rigid registration technique has been applied to register these images. It is noticeably observed that the image intensity changes at tumor are less than those at surrounding which induce a detectable contrast. Addition of this compression induced contrast to the simulated and experimental images has improved their original contrast by a factor of about 1.4

  10. Clinical evaluation of radionuclide cisternography and x-ray CT in normal pressure hydrocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Osamu; Maeda, Toshio; Matsuda, Hiroshi; Ishida, Hiroko; Michigishi, Takatoshi (Kanazawa Univ. (Japan). School of Medicine)

    1983-06-01

    The retrospective reevaluation of the radionuclide cisternogram and X-ray CT were studied in 14 cases in whom cerebrospinal fluid shunt were installed under the diagnosis of normal pressure hydrocephalus after these examinations. Only half of these cases showed clinical improvement after shunt operation. The most reliable finding of the cisternography was the persistent ventricular visualization with bilateral block at subarachnoid space on 48 hour image. These findings were observed in seven cases, and all of them but one case showed clinical improvement after shunt installation. The exceptional one case in whom shunt was not effective. The cisternogram of the other case whose shunt was effective showed the transient ventricular visualization upto 24 hour, the unilateral subarachnoidal space block upto 48 hour and the prominently delayed clearance of radionuclide from the head. The cisternographic findings of the delayed radionuclide clearance and the ventricular visualization on 24 hour-image were insufficient to help the shunt effect. The most hopeful findings of the X-ray CT was the poor-visualization of Sylvian fissure at least on two cross sections. These findings were observed in eight cases, and six out of them showed clinical improvement after shunt operation. But the poor-visualization of Sylvian fissure is not a specific sign for normal pressure hydrocephalus. We concluded that the abnormal findings on 48 hour-image of cisternography are correlated well with the effect of cerebrospinal fluid shunt in normal pressure hydrocephalus, and the cisternography is still very useful in the chosen patients with clinical and X-ray CT findings.

  11. An x-ray CT polymer gel dosimetry prototype: I. Remnant artefact removal.

    Science.gov (United States)

    Jirasek, A; Carrick, J; Hilts, M

    2012-05-21

    In this study a new x-ray CT polymer gel dosimetry (PGD) filtering technique is presented for the removal of (i) remnant ring and streak artefacts, and (ii) 'structured' noise in the form of minute, intrinsic gel density fluctuations. It is shown that the noise present within x-ray CT PGD images is not purely stochastic (pixel by pixel) in nature, but rather is 'structured', and hence purely stochastic-based noise-removal filters fail in removing this significant, unwanted noise component. The remnant artefact removal (RAR) technique is based on a class of signal stripping (i.e. baseline-estimation) algorithms typically used in the estimation of unwanted non-uniform baselines underlying spectral data. Here the traditional signal removal algorithm is recast, whereby the 'signal' that is removed is the structured noise and remnant artefacts, leaving the desired polymer gel dose distribution. The algorithm is extended to 2D and input parameters are optimized for PGD images. RAR filter results are tested on (i) synthetic images with measured gel background images added, in order to accurately represent actual noise present in PGD images, and (ii) PGD images of a three-field gel irradiation. RAR results are compared to a top-performing noise filter (adaptive mean, AM), used in previous x-ray CT PGD studies. It is shown that, in all cases, the RAR filter outperforms the AM filter, particularly in cases where either (i) a low-dose gel image has been acquired or (ii) the signal-to-noise ratio of the PG image is low, as in the case when a low number of image averages are acquired within a given experiment. Guidelines for the implementation of the RAR filter are given.

  12. Fourier domain image fusion for differential X-ray phase-contrast breast imaging.

    Science.gov (United States)

    Coello, Eduardo; Sperl, Jonathan I; Bequé, Dirk; Benz, Tobias; Scherer, Kai; Herzen, Julia; Sztrókay-Gaul, Anikó; Hellerhoff, Karin; Pfeiffer, Franz; Cozzini, Cristina; Grandl, Susanne

    2017-04-01

    X-Ray Phase-Contrast (XPC) imaging is a novel technology with a great potential for applications in clinical practice, with breast imaging being of special interest. This work introduces an intuitive methodology to combine and visualize relevant diagnostic features, present in the X-ray attenuation, phase shift and scattering information retrieved in XPC imaging, using a Fourier domain fusion algorithm. The method allows to present complementary information from the three acquired signals in one single image, minimizing the noise component and maintaining visual similarity to a conventional X-ray image, but with noticeable enhancement in diagnostic features, details and resolution. Radiologists experienced in mammography applied the image fusion method to XPC measurements of mastectomy samples and evaluated the feature content of each input and the fused image. This assessment validated that the combination of all the relevant diagnostic features, contained in the XPC images, was present in the fused image as well.

  13. Indirect-detection single-photon-counting x-ray detector for breast tomosynthesis

    Science.gov (United States)

    Jiang, Hao; Kaercher, Joerg; Durst, Roger

    2016-03-01

    X-ray mammography is a crucial screening tool for early identification of breast cancer. However, the overlap of anatomical features present in projection images often complicates the task of correctly identifying suspicious masses. As a result, there has been increasing interest in acquisition of volumetric information through digital breast tomosynthesis (DBT) which, compared to mammography, offers the advantage of depth information. Since DBT requires acquisition of many projection images, it is desirable that the noise in each projection image be dominated by the statistical noise of the incident x-ray quanta and not by the additive noise of the imaging system (referred to as quantum-limited imaging) and that the cumulative dose be as low as possible (e.g., no more than for a mammogram). Unfortunately, the electronic noise (~2000 electrons) present in current DBT systems based on active matrix, flat-panel imagers (AMFPIs) is still relatively high compared with modest x-ray gain of the a-Se and CsI:Tl x-ray converters often used. To overcome the modest signal-to-noise ratio (SNR) limitations of current DBT systems, we have developed a large-area x-ray imaging detector with the combination of an extremely low noise (~20 electrons) active-pixel CMOS and a specially designed high resolution scintillator. The high sensitivity and low noise of such system provides better SNR by at least an order of magnitude than current state-of-art AMFPI systems and enables x-ray indirect-detection single photon counting (SPC) at mammographic energies with the potential of dose reduction.

  14. X-ray CT high-density artefact suppression in the presence of bones

    Energy Technology Data Exchange (ETDEWEB)

    Wei Jikun [School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051 (United States); Chen Laigao [BioImaging Center of Emphasis, Pfizer Global Research and Development, 2800 Plymouth RD, Ann Arbor, MI 48105 (United States); Sandison, George A [School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051 (United States); Liang Yun [Department of Radiology, Indiana University Medical School, Indianapolis, IN 46202 (United States); Xu, Lisa X [School of Mechanical Engineering, 585 Purdue Mall, West Lafayette, IN 47907-2040 (United States)

    2004-12-21

    This paper presents a novel method of reducing x-ray CT high-density artefacts generated by metal objects when abundant bone structures are present in the region of interest. This method has an advantage over previously proposed methods since it heavily suppresses the metal artefacts without introducing extra bone artefacts. The method of suppression requires that bone pixels are isolated and segmented by thresholding. Then artificial CT numbers are assigned to the bone pixels so that their projection profiles are smooth and thus can be properly simulated by a polynomial interpolation. The projection profile of the metal object is then removed to fully suppress the artefacts. The resulting processed profile is fed to a reconstruction routine and the previously preserved bone pixels added back. The new method utilizes two important features of the CT image with metal artefacts: (a) metal and bone pixels are not severely affected by the high-density artefacts and (b) the high-density artefacts can be located in specific projection channels in the profile domain, although they are spread out in the image domain. This suppression method solves the problem of CT image artefacts arising from metal objects in the body. It has the potential to greatly improve diagnostic CT imaging in the presence of these objects and treatment planning that utilizes CT for patients with metal applicators (e.g., brachytherapy for cervix cancer and prostate cryotherapy)

  15. Measurement of breast-tissue x-ray attenuation by spectral mammography: solid lesions

    Science.gov (United States)

    Fredenberg, Erik; Kilburn-Toppin, Fleur; Willsher, Paula; Moa, Elin; Danielsson, Mats; Dance, David R.; Young, Kenneth C.; Wallis, Matthew G.

    2016-04-01

    Knowledge of x-ray attenuation is essential for developing and evaluating x-ray imaging technologies. For instance, techniques to distinguish between cysts and solid tumours at mammography screening would be highly desirable to reduce recalls, but the development requires knowledge of the x-ray attenuation for cysts and tumours. We have previously measured the attenuation of cyst fluid using photon-counting spectral mammography. Data on x-ray attenuation for solid breast lesions are available in the literature, but cover a relatively wide range, likely caused by natural spread between samples, random measurement errors, and different experimental conditions. In this study, we have adapted a previously developed spectral method to measure the linear attenuation of solid breast lesions. A total of 56 malignant and 5 benign lesions were included in the study. The samples were placed in a holder that allowed for thickness measurement. Spectral (energy-resolved) images of the samples were acquired and the image signal was mapped to equivalent thicknesses of two known reference materials, which can be used to derive the x-ray attenuation as a function of energy. The spread in equivalent material thicknesses was relatively large between samples, which is likely to be caused mainly by natural variation and only to a minor extent by random measurement errors and sample inhomogeneity. No significant difference in attenuation was found between benign and malignant solid lesions. The separation between cyst-fluid and tumour attenuation was, however, significant, which suggests it may be possible to distinguish cystic from solid breast lesions, and the results lay the groundwork for a clinical trial. In addition, the study adds a relatively large sample set to the published data and may contribute to a reduction in the overall uncertainty in the literature.

  16. X-Ray Nanofocus CT: Visualising Of Internal 3D-Structures With Submicrometer Resolution

    Science.gov (United States)

    Weinekoetter, Christian

    2008-09-01

    High-resolution X-ray Computed Tomography (CT) allows the visualization and failure analysis of the internal micro structure of objects—even if they have complicated 3D-structures where 2D X-ray microscopy would give unclear information. During the past several years, computed tomography has progressed to higher resolution and quicker reconstruction of the 3D-volume. Most recently it even allows a three-dimensional look into the inside of materials with submicron resolution. With the use of nanofocus® tube technology, nanoCT®-systems are pushing forward into application fields that were exclusive to high cost and rare available synchrotron techniques. The study was performed with the new nanotom, a very compact laboratory system which allows the analysis of samples up to 120 mm in diameter and weighing up to 1 kg with exceptional voxel-resolution down to click, this technique will substitute destructive mechanical slicing and cutting in many applications. The initial CT results obtained with the nanotom® demonstrate that it is now possible to analyze the three-dimensional micro structure of materials and small objects with submicrometer resolution. Any internal difference in material, density or porosity within a sample can be visualized and data like distances can be measured. NanoCT® widely expands the spectrum of detectable micro-structures. The nanotom® opens a new dimension of 3D-microanalysis and will replace more destructive methods—saving costs and time per sample inspected.

  17. Influence of voxel size settings in X-Ray CT Imagery of soil in scaling properties

    Science.gov (United States)

    Heck, R.; Scaiff, N. T.; Andina, D.; Tarquis, A. M.

    2012-04-01

    Fundamental to the interpretation and comparison of X-ray CT imagery of soil is recognition of the objectivity and consistency of procedures used to generate the 3D models. Notably, there has been a lack of consistency in the size of voxels used for diverse interpretations of soils features and processes; in part, this is due to the ongoing evolution of instrumentation and computerized image processing capacity. Moreover, there is still need for discussion on whether standard voxels sizes should be recommended, and what those would be. Regardless of any eventual adoption of such standards, there is a need to also consider the manner in which voxel size is set in the 3D imagery. In the typical approaches to X-ray CT imaging, voxel size may be set at three stages: image acquisition (involving the position of the sample relative to the tube and detector), image reconstruction (where binning of pixels in the acquired images may occur), as well as post-reconstruction re-sampling (which may involve algorithms such as tri-cubic convolution). This research evaluates and compares the spatial distribution of intra-aggregate voids in 3D imagery as well as their scaling properties, of equivalent voxel size, generated using various combinations of the afore-mentioned approaches. Funding provided by Spanish Ministerio de Ciencia e Innovación (MICINN) through project no. AGL2010-21501/AGR is greatly appreciated.

  18. Using mastectomy specimens to develop breast models for breast tomosynthesis and CT breast imaging

    Science.gov (United States)

    O'Connor, J. Michael; Das, Mini; Didier, Clay; Mah'D, Mufeed; Glick, Stephen J.

    2008-03-01

    Dedicated x-ray computed tomography (CT) of the breast using a cone-beam flat-panel detector system is a modality under investigation by a number of research teams. As previously reported, we have fabricated a prototype, bench-top flat-panel CT breast imaging (CTBI) system and developed computer simulation software to model such a system. We are developing a methodology to use high resolution, low noise CT reconstructions of fresh mastectomy specimens for generating an ensemble of 3D digital breast phantoms that realistically model 3D compressed and uncompressed breast anatomy. These breast models can be used to simulate realistic projection data for both breast tomosynthesis (BT) and CT systems thereby providing a powerful evaluation and optimization mechanism.

  19. Performance and applications of GaAs:Cr-based Medipix detector in X-ray CT

    Science.gov (United States)

    Kozhevnikov, D.; Chelkov, G.; Demichev, M.; Gridin, A.; Smolyanskiy, P.; Zhemchugov, A.

    2017-01-01

    In the recent years, the method of single photon counting X-ray μ-CT is being actively developed and applied in various fields. Results of our studies carried out using the MARS μ-CT scanner equipped with GaAs Medipix-based camera are presented. The procedure of mechanical alignment of the scanner is described, including direct and indirect measurements of the spatial resolution. The software chain for data processing and reconstruction has been developed and reported. We demonstrate the possibility to apply the scanner for research in geology and medicine and provide demo images of geological samples (chrome spinellids, titanium magnetite ore) and medical samples (atherosclerotic plaque, abdominal aortic aneurysm). The first results of multi-energy scans using GaAs:Cr-based camera are shown.

  20. Visualization of soil particulate organic matter by means of X-ray CT?

    Science.gov (United States)

    Sleutel, Steven; Van Loo, Denis; Maenhout, Peter; Van Hoorebeke, Luc; Cnudde, Veerle; De Neve, Stefaan

    2014-05-01

    The role of soil structure in organic matter (OM) stabilization has been primarily investigated through physical fractionation studies operative at the scale of aggregates and smaller organo-mineral particles. By narrowing down soil structure to an arrangement of mineral and organic particles, the majority of studies did not explore the spatial organization of the soil pore network, the actual habitat of microorganisms. The pore structure of soil can have a significant impact on soil processes like OM decomposition by excluding OM from micro-organisms in small pores, by regulating the diffusion of substrates and metabolites and by regulating aeration and presence of moisture. Because of its ability to visualize the 3D architecture of soil non-destructively, X-ray Computed Tomography (CT) is becoming a widespread tool for studying soil pore network structure. However, phase determination of pore space, soil OM, soil mineral matter (MM) and water is often limited even with the latest technological and software advances, allowing high resolution and better quality imaging. Contrast agents commonly used in histology enable enhancement of X-ray attenuation of targeted structures or compounds. Here we report on the first systematic investigation of the use of such X-ray contrast agents for soil research. An evaluation procedure as well as a method to apply the agents to soil samples was developed and applied on reference soil samples. The effectiveness and selectivity of the contrast agents was evaluated for soil organic matter (SOM), MM and water. Several products were found to selectively increase the attenuation of water or SOM. The four agents with the best OM-staining capabilities (Phosphomolybdenic acid (PMA), silver nitrate, lead nitrate and lead acetate) were further tested on an OM-MM mixture. Observed differences in reactivity of the staining agents with MM components were apparent, suggesting that contrasting agents may have to be selected for the specific

  1. Characterization of materials for optimal near-infrared and x-ray imaging of the breast.

    Science.gov (United States)

    Michaelsen, Kelly; Krishnaswamy, Venkataramanan; Pogue, Brian W; Brooks, Ken; Defreitas, Ken; Shaw, Ian; Poplack, Steven P; Paulsen, Keith D

    2012-09-01

    Development of a detector case for complete co-registration of images in a non-fiber-based combined near-infrared spectral tomography and digital breast tomosynthesis, required analysis to find materials that could support a breast under full mammographic compression without affecting the x-ray images or the quality of the near infrared measurements. Several possible solutions were considered, and many types of plastics were tested in the development of the detector case. Light channeling within the detector case changed the data obtained in resin and agarose phantoms, lowering recovered absorption values. Additional developments focusing on blocking stray light were successful and permitted a normal subject imaging exam.

  2. Suppression of high-density artifacts in x-ray CT images using temporal digital subtraction with application to cryotherapy

    Science.gov (United States)

    Baissalov, Roustem; Sandison, George A.; Donnelly, Bryan J.; Saliken, John C.; Muldrew, Ken; Rewcastle, John C.

    2000-06-01

    Image guidance of cryotherapy is usually performed using ultrasound or x-ray CT. Despite the ability of CT to display the full 3D structure of the iceball, including frozen and unfrozen regions, the quality of the images is compromised by the presence of high density streak artifacts. To suppress these artifacts we applied Temporal Digital Subtraction (TDS). This TDS method has the added advantage of improving the gray scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high density artifacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced content of the artifacts. This TDS can be used in x-ray CT assisted cryotherapy to significantly suppress or eliminate high density x-ray CT streak artifacts by digitally processing x-ray CT images. Applying TDS in cryotherapy will facilitate estimation of the amount and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent.

  3. X-ray scattering for the characterization of lyophilized breast tissue samples

    Science.gov (United States)

    Elshemey, Wael M.; Mohamed, Fayrouz S.; Khater, Ibrahim M.

    2013-09-01

    This work investigates the possibility of characterizing breast cancer by measuring the X-ray scattering profiles of lyophilized excised breast tissue samples. Since X-ray scattering from water-rich tissue is dominated by scattering from water, the removal of water by lyophilization would enhance the characterization process. In the present study, X-ray scattering profiles of 22 normal, 22 malignant and 10 benign breast tissue samples are measured. The cut-offs of scatter diagrams, sensitivity, specificity and diagnostic accuracy of three characterization parameters (full width at half maximum (FWHM) for the peak at 1.1 nm-1, area under curve (AUC), and ratio of 1st to 2nd scattering peak intensities (I1/I2%)) are calculated and compared to the data from non-lyophilized samples. Results show increased sensitivity (up to 100%) of the present data on lyophilized breast tissue samples compared to previously reported data for non-lyophilized samples while the specificity (up to 95.4%), diagnostic accuracy (up to 95.4%) and receiver operating characteristic (ROC) curve values (up to 0.9979) for both sets of data are comparable. The present study shows significant differences between normal samples and each of malignant and benign samples. Only subtle differences exist between malignant and benign lyophilized breast tissue samples where FWHM=0.7±0.1 and 0.8±0.3, AUC=1.3±0.2 and 1.4±0.2 and I1/I2%=44.9±11.0 and 52.4±7.6 for malignant and benign samples respectively.

  4. Temporal dynamics for soil aggregates determined using X-ray CT scanning

    DEFF Research Database (Denmark)

    Garbout, Amin; Munkholm, Lars Juhl; Hansen, Søren Baarsgaard

    2013-01-01

    Soil structure plays a key role in the ability of soil to fulfil essential soil functions and services in relation to e.g. root growth, gas and water transport and organic matter turnover. However, soils are not a very easy object to study as they are highly complex and opaque to the human eye....... Traditionally, they have been studied using invasive or destructive techniques. The advantage of using X-ray computed tomography (CT) in soil morphology is that it enables non-destructive quantification of soil structure in three dimensions (3D). The prime objective of the present study was to characterize soil...... aggregate properties such as volume, surface area and sphericity based on 3D images. We tested the methods on aggregates from different treatments and quantified changes over time. A total of 32 collections of aggregates, enclosed in mesocosms, were incubated in soil to follow the structural changes over...

  5. X-ray CT monitoring of iceball growth and thermal distribution during cryosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Sandison, G.A.; Loye, M.P.; Rewcastle, J.C. [Departments of Oncology and Medical Physics, Tom Baker Cancer Centre, Calgary, Canada T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Canada T2N 2N4 (Canada); Hahn, L.J. [Department of Physics and Astronomy, University of Calgary, Calgary, Canada T2N 2N4 (Canada); Department of Diagnostic Imaging, Foothills Hospital, Calgary, Canada T2N 2T7 (Canada); Saliken, J.C. [Department of Diagnostic Imaging, Foothills Hospital, Calgary, Canada T2N 2T7 (Canada); Department of Surgery, Tom Baker Cancer Centre, Calgary, Canada T2N 4N2 (Canada); McKinnon, J.G. [Department of Surgery, Foothills Hospital, Calgary, Canada T2N 2T7 (Canada); Donnelly, B.J. [Department of Surgery, Tom Baker Cancer Centre, Calgary, Canada T2N 4N2 (Canada)

    1998-11-01

    X-ray CT is able to image the internal architecture of frozen tissue. Phantoms of distilled water, a saline-gelatin mixture, lard and a calf liver-gelatin suspension cooled by a plastic tube acting as a long liquid nitrogen cryoprobe were used to study the relationship between Hounsfield unit (HU) values and temperature. There is a signature change in HU value from unfrozen to completely frozen tissue. No discernible relation exists between temperature in a completely frozen tissue and its HU value for the temperature range achieved with commercial cryoprobes. However, such a relation does exist in the typically narrow region of phase change and it is this change in HU value that is the parameter of concern for quantitative monitoring of the freezing process. Calibration of temperature against change in HU value allows a limited set of isotherms to be generated in the phase change region for direct monitoring of iceball growth. The phase change temperature range, mid-phase change temperature and the absolute value of HU change from completely frozen to unfrozen tissue are shown to be sensitive to the medium. Modelling of the temperature distribution within the region of completely frozen phantom using the infinite cylinder solution to the Fourier heat equation allows the temperature history of the phantom to be predicted. A set of isotherms, generated using a combination of thermal modelling and calibrated HU values demonstrates the feasibility of routine x-ray CT assisted cryotherapy. Isotherm overlay will be a major aid to the cryosurgeon who adopts a fixed target temperature as the temperature below which there is a certainty of ablation of the diseased tissue. (author)

  6. Morphological and quantitative analyses on features of asymmetric mandible with X-ray CT images

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Masaki; Isshiki, Yasushige; Nishikawa, Keiichi [Tokyo Dental Coll., Chiba (Japan)

    2001-09-01

    Biomechanical disproportion of the mandible causes morphological and quantitative changes in the bone and induces jaw deformities. The purpose of this study was to clarify the influence of the biomechanical disproportion on the structure and quality of the mandible, using spiral X-ray CT images. Subjects were 11 patients with mandibular asymmetry requiring orthognathic surgery. Lateral and vertical shift angles of the mandible against the maxilla were determined mathematically from the coordinates of structural reference points in 3-dimensional orthogonal coordinate systems as indices of the deformity degree. Several properties concerning thickness and CT value of mandibular cortical bone were measured as indices of the morphological and quantitative changes in mandibular cortical bone. Occlusal force was also measured using a pressure sensitive film as an index of biomechanical disproportion. Asymmetric indices of them were calculated from data of the left and right sides. The Pearson's correlation coefficients were obtained for these data. As a result, the mandible tended to shift laterally toward the side where the occlusal force at the second molar region was stronger and also to shift upward on that side. At the central incisor region of the laterally shifted side, CT values were relatively decreased. At the lateral incisor region, cortical bone density was relatively increased. At the first bicuspid region and the posterior tooth regions, cortical bone thickness was relatively decreased. (author)

  7. Evaluation of accelerated iterative x-ray CT image reconstruction using floating point graphics hardware

    Science.gov (United States)

    Kole, J. S.; Beekman, F. J.

    2006-02-01

    Statistical reconstruction methods offer possibilities to improve image quality as compared with analytical methods, but current reconstruction times prohibit routine application in clinical and micro-CT. In particular, for cone-beam x-ray CT, the use of graphics hardware has been proposed to accelerate the forward and back-projection operations, in order to reduce reconstruction times. In the past, wide application of this texture hardware mapping approach was hampered owing to limited intrinsic accuracy. Recently, however, floating point precision has become available in the latest generation commodity graphics cards. In this paper, we utilize this feature to construct a graphics hardware accelerated version of the ordered subset convex reconstruction algorithm. The aims of this paper are (i) to study the impact of using graphics hardware acceleration for statistical reconstruction on the reconstructed image accuracy and (ii) to measure the speed increase one can obtain by using graphics hardware acceleration. We compare the unaccelerated algorithm with the graphics hardware accelerated version, and for the latter we consider two different interpolation techniques. A simulation study of a micro-CT scanner with a mathematical phantom shows that at almost preserved reconstructed image accuracy, speed-ups of a factor 40 to 222 can be achieved, compared with the unaccelerated algorithm, and depending on the phantom and detector sizes. Reconstruction from physical phantom data reconfirms the usability of the accelerated algorithm for practical cases.

  8. Evaluation of accelerated iterative x-ray CT image reconstruction using floating point graphics hardware

    Energy Technology Data Exchange (ETDEWEB)

    Kole, J S; Beekman, F J [Image Sciences Institute, Department of Nuclear Medicine and Department of Pharmacology and Anatomy, Rudolf Magnus Institute of Neuroscience, UMC Utrecht, Universiteitsweg 100, STR5.203, 3584 CG Utrecht (Netherlands)

    2006-02-21

    Statistical reconstruction methods offer possibilities to improve image quality as compared with analytical methods, but current reconstruction times prohibit routine application in clinical and micro-CT. In particular, for cone-beam x-ray CT, the use of graphics hardware has been proposed to accelerate the forward and back-projection operations, in order to reduce reconstruction times. In the past, wide application of this texture hardware mapping approach was hampered owing to limited intrinsic accuracy. Recently, however, floating point precision has become available in the latest generation commodity graphics cards. In this paper, we utilize this feature to construct a graphics hardware accelerated version of the ordered subset convex reconstruction algorithm. The aims of this paper are (i) to study the impact of using graphics hardware acceleration for statistical reconstruction on the reconstructed image accuracy and (ii) to measure the speed increase one can obtain by using graphics hardware acceleration. We compare the unaccelerated algorithm with the graphics hardware accelerated version, and for the latter we consider two different interpolation techniques. A simulation study of a micro-CT scanner with a mathematical phantom shows that at almost preserved reconstructed image accuracy, speed-ups of a factor 40 to 222 can be achieved, compared with the unaccelerated algorithm, and depending on the phantom and detector sizes. Reconstruction from physical phantom data reconfirms the usability of the accelerated algorithm for practical cases.

  9. Improved Diagnostics by Assessing the Micromorphology of Breast Calcifications via X-Ray Dark-Field Radiography

    Science.gov (United States)

    Scherer, Kai; Braig, Eva; Ehn, Sebastian; Schock, Jonathan; Wolf, Johannes; Birnbacher, Lorenz; Chabior, Michael; Herzen, Julia; Mayr, Doris; Grandl, Susanne; Sztrókay-Gaul, Anikó; Hellerhoff, Karin; Pfeiffer, Franz

    2016-11-01

    Breast microcalcifications play an essential role in the detection and evaluation of early breast cancer in clinical diagnostics. However, in digital mammography, microcalcifications are merely graded with respect to their global appearance within the mammogram, while their interior microstructure remains spatially unresolved and therefore not considered in cancer risk stratification. In this article, we exploit the sub-pixel resolution sensitivity of X-ray dark-field contrast for clinical microcalcification assessment. We demonstrate that the micromorphology, rather than chemical composition of microcalcification clusters (as hypothesised by recent literature), determines their absorption and small-angle scattering characteristics. We show that a quantitative classification of the inherent microstructure as ultra-fine, fine, pleomorphic and coarse textured is possible. Insights underlying the micromorphological nature of breast calcifications are verified by comprehensive high-resolution micro-CT measurements. We test the determined microtexture of microcalcifications as an indicator for malignancy and demonstrate its potential to improve breast cancer diagnosis, by providing a non-invasive tool for sub-resolution microcalcification assessment. Our results indicate that dark-field imaging of microcalcifications may enhance the diagnostic validity of current microcalcification analysis and reduce the number of invasive procedures.

  10. CT x-ray tube voltage optimisation and image reconstruction evaluation using visual grading analysis

    Science.gov (United States)

    Zheng, Xiaoming; Kim, Ted M.; Davidson, Rob; Lee, Seongju; Shin, Cheongil; Yang, Sook

    2014-03-01

    The purposes of this work were to find an optimal x-ray voltage for CT imaging and to determine the diagnostic effectiveness of image reconstruction techniques by using the visual grading analysis (VGA). Images of the PH-5 CT abdomen phantom (Kagaku Co, Kyoto) were acquired by the Toshiba Aquillion One 320 slices CT system with various exposures (from 10 to 580 mAs) under different tube peak voltages (80, 100 and 120 kVp). The images were reconstructed by employing the FBP and the AIDR 3D iterative reconstructions with Mild, Standard and Strong FBP blending. Image quality was assessed by measuring noise, contrast to noise ratio and human observer's VGA scores. The CT dose index CTDIv was obtained from the values displayed on the images. The best fit for the curves of the image quality VGA vs dose CTDIv is a logistic function from the SPSS estimation. A threshold dose Dt is defined as the CTDIv at the just acceptable for diagnostic image quality and a figure of merit (FOM) is defined as the slope of the standardised logistic function. The Dt and FOM were found to be 5.4, 8.1 and 9.1 mGy and 0.47, 0.51 and 0.38 under the tube voltages of 80, 100 and 120 kVp, respectively, from images reconstructed by the FBP technique. The Dt and FOM values were lower from the images reconstructed by the AIDR 3D in comparison with the FBP technique. The optimal xray peak voltage for the imaging of the PH-5 abdomen phantom by the Aquillion One CT system was found to be at 100 kVp. The images reconstructed by the FBP are more diagnostically effective than that by the AIDR 3D but with a higher dose Dt to the patients.

  11. A measurement-based X-ray source model characterization for CT dosimetry computations.

    Science.gov (United States)

    Sommerville, Mitchell; Poirier, Yannick; Tambasco, Mauro

    2015-11-08

    The purpose of this study was to show that the nominal peak tube voltage potential (kVp) and measured half-value layer (HVL) can be used to generate energy spectra and fluence profiles for characterizing a computed tomography (CT) X-ray source, and to validate the source model and an in-house kV X-ray dose computation algorithm (kVDoseCalc) for computing machine- and patient-specific CT dose. Spatial variation of the X-ray source spectra of a Philips Brilliance and a GE Optima Big Bore CT scanner were found by measuring the HVL along the direction of the internal bow-tie filter axes. Third-party software, Spektr, and the nominal kVp settings were used to generate the energy spectra. Beam fluence was calculated by dividing the integral product of the spectra and the in-air NIST mass-energy attenuation coefficients by in-air dose measurements along the filter axis. The authors found the optimal number of photons to seed in kVDoseCalc to achieve dose convergence. The Philips Brilliance beams were modeled for 90, 120, and 140 kVp tube settings. The GE Optima beams were modeled for 80, 100, 120, and 140 kVp tube settings. Relative doses measured using a Capintec Farmer-type ionization chamber (0.65 cc) placed in a cylindrical polymethyl methacrylate (PMMA) phantom and irradiated by the Philips Brilliance, were compared to those computed with kVDoseCalc. Relative doses in an anthropomorphic thorax phantom (E2E SBRT Phantom) irradiated by the GE Optima were measured using a (0.015 cc) PTW Freiburg ionization chamber and compared to computations from kVDoseCalc. The number of photons required to reduce the average statistical uncertainty in dose to < 0.3% was 2 × 105. The average percent difference between calculation and measurement over all 12 PMMA phantom positions was found to be 1.44%, 1.47%, and 1.41% for 90, 120, and 140 kVp, respectively. The maximum percent difference between calculation and measurement for all energies, measurement positions, and phantoms was

  12. Characterization of multi-layered fish scales (Atractosteus spatula) using nanoindentation, X-ray CT, FTIR, and SEM.

    Science.gov (United States)

    Allison, Paul G; Rodriguez, Rogie I; Moser, Robert D; Williams, Brett A; Poda, Aimee R; Seiter, Jennifer M; Lafferty, Brandon J; Kennedy, Alan J; Chandler, Mei Q

    2014-07-10

    The hierarchical architecture of protective biological materials such as mineralized fish scales, gastropod shells, ram's horn, antlers, and turtle shells provides unique design principles with potentials for guiding the design of protective materials and systems in the future. Understanding the structure-property relationships for these material systems at the microscale and nanoscale where failure initiates is essential. Currently, experimental techniques such as nanoindentation, X-ray CT, and SEM provide researchers with a way to correlate the mechanical behavior with hierarchical microstructures of these material systems1-6. However, a well-defined standard procedure for specimen preparation of mineralized biomaterials is not currently available. In this study, the methods for probing spatially correlated chemical, structural, and mechanical properties of the multilayered scale of A. spatula using nanoindentation, FTIR, SEM, with energy-dispersive X-ray (EDX) microanalysis, and X-ray CT are presented.

  13. Development of high spatial resolution X-ray CT system at BL47XU in SPring-8

    CERN Document Server

    Uesugi, K; Yagi, N; Tsuchiyama, A; Nakano, T

    2001-01-01

    High spatial resolution, micrometer range, X-ray CT system has been developed at SPring-8. The experiments were performed at the undulator beam line BL47XU. An 'in-vacuum type' undulator is employed as an X-ray source, and the X-rays are monochromatized with a liquid nitrogen cooled Si(1 1 1) double crystal monochromator. High precision rotation stage with air bearing was used for sample rotation. The transmitted images were obtained with a two-dimensional image detector, which consists of a single crystal phosphor screen (Lu sub 2 SiO sub 5 : Ce), an objective lens and a cooled CCD camera. In this system the smallest effective pixel size was set to 0.5 mu mx0.5 mu m. As a result of the experiments, three-dimensional images of a few micrometer-order texture has been successfully obtained with the developed CT system.

  14. Accelerating statistical image reconstruction algorithms for fan-beam x-ray CT using cloud computing

    Science.gov (United States)

    Srivastava, Somesh; Rao, A. Ravishankar; Sheinin, Vadim

    2011-03-01

    Statistical image reconstruction algorithms potentially offer many advantages to x-ray computed tomography (CT), e.g. lower radiation dose. But, their adoption in practical CT scanners requires extra computation power, which is traditionally provided by incorporating additional computing hardware (e.g. CPU-clusters, GPUs, FPGAs etc.) into a scanner. An alternative solution is to access the required computation power over the internet from a cloud computing service, which is orders-of-magnitude more cost-effective. This is because users only pay a small pay-as-you-go fee for the computation resources used (i.e. CPU time, storage etc.), and completely avoid purchase, maintenance and upgrade costs. In this paper, we investigate the benefits and shortcomings of using cloud computing for statistical image reconstruction. We parallelized the most time-consuming parts of our application, the forward and back projectors, using MapReduce, the standard parallelization library on clouds. From preliminary investigations, we found that a large speedup is possible at a very low cost. But, communication overheads inside MapReduce can limit the maximum speedup, and a better MapReduce implementation might become necessary in the future. All the experiments for this paper, including development and testing, were completed on the Amazon Elastic Compute Cloud (EC2) for less than $20.

  15. Low-dose CT of the paranasal sinuses. Minimizing X-ray exposure with spectral shaping

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, Wolfgang [Friedrich-Alexander-University Erlangen-Nuremberg, Radiological Institute, Erlangen (Germany); Radiological Institute, Erlangen (Germany); May, Matthias; Saake, Marc; Brand, Michael; Uder, Michael; Lell, Michael [Friedrich-Alexander-University Erlangen-Nuremberg, Radiological Institute, Erlangen (Germany)

    2016-11-15

    Shaping the energy spectrum of the X-ray beam has been shown to be beneficial in low-dose CT. This study's aim was to investigate dose and image quality of tin filtration at 100 kV for pre-operative planning in low-dose paranasal CT imaging in a large patient cohort. In a prospective trial, 129 patients were included. 64 patients were randomly assigned to the study protocol (100 kV with additional tin filtration, 150mAs, 192 x 0.6-mm slice collimation) and 65 patients to the standard low-dose protocol (100 kV, 50mAs, 128 x 0.6-mm slice collimation). To assess the image quality, subjective parameters were evaluated using a five-point scale. This scale was applied on overall image quality and contour delineation of critical anatomical structures. All scans were of diagnostic image quality. Bony structures were of good diagnostic image quality in both groups, soft tissues were of sufficient diagnostic image quality in the study group because of a high level of noise. Radiation exposure was very low in both groups, but significantly lower in the study group (CTDI{sub vol} 1.2 mGy vs. 4.4 mGy, p < 0.001). Spectral optimization (tin filtration at 100 kV) allows for visualization of the paranasal sinus with sufficient image quality at a very low radiation exposure. (orig.)

  16. A weighted polynomial based material decomposition method for spectral x-ray CT imaging

    Science.gov (United States)

    Wu, Dufan; Zhang, Li; Zhu, Xiaohua; Xu, Xiaofei; Wang, Sen

    2016-05-01

    Currently in photon counting based spectral x-ray computed tomography (CT) imaging, pre-reconstruction basis materials decomposition is an effective way to reconstruct densities of various materials. The iterative maximum-likelihood method requires precise spectrum information and is time-costly. In this paper, a novel non-iterative decomposition method based on polynomials is proposed for spectral CT, whose aim was to optimize the noise performance when there is more energy bins than the number of basis materials. Several subsets were taken from all the energy bins and conventional polynomials were established for each of them. The decomposition results from each polynomial were summed with pre-calculated weighting factors, which were designed to minimize the overall noises. Numerical studies showed that the decomposition noise of the proposed method was close to the Cramer-Rao lower bound under Poisson noises. Furthermore, experiments were carried out with an XCounter Filte X1 photon counting detector for two-material decomposition and three-material decomposition for validation.

  17. Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Baissalov, R.; Sandison, G.A.; Rewcastle, J.C. [Department of Medical Physics, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 2 Department of Physics and Astronomy, University of Calgary, Calgary T2N 2N4 (Canada); Donnelly, B.J. [Department of Surgery, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 4 Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Saliken, J.C. [Department of Surgery, Tom Baker Cancer Center, Calgary T2N 4N2 (Canada); Department of Diagnostic Imaging, Foothills Hospital, Calgary T2N 2T7 (Canada); McKinnon, J.G. [Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Muldrew, K. [Department of Surgery, Faculty of Medicine, University of Calgary, Calgary T2N 2T7 (Canada)

    2000-05-01

    Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey-scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high-density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent. (author)

  18. Whole-body adipose tissue analysis: comparison of MRI, CT and dual energy X-ray absorptiometry

    DEFF Research Database (Denmark)

    Kullberg, J; Brandberg, J; Angelhed, J-E

    2009-01-01

    The aim of this study was to validate a recently proposed MRI-based T(1)-mapping method for analysis of whole-body adipose tissue (AT) using an established CT protocol as reference and to include results from dual energy X-ray absorptiometry (DEXA). 10 subjects, drawn from the Swedish Obese...

  19. Impact of miscentering on patient dose and image noise in x-ray CT imaging : Phantom and clinical studies

    NARCIS (Netherlands)

    Habibzadeh, M. A.; Ay, M. R.; Asl, A. R. Kamali; Ghadiri, H.; Zaidi, H.

    2012-01-01

    The operation of the bowtie filter in x-ray CT is correct if the object being scanned is properly centered in the scanner's field-of-view. Otherwise, the dose delivered to the patient and image noise will deviate from optimal setting. We investigate the effect of miscentering on image noise and surf

  20. X-ray CT-Derived Soil Characteristics Explain Varying Air, Water, and Solute Transport Properties across a Loamy Field

    DEFF Research Database (Denmark)

    Paradelo Pérez, Marcos; Katuwal, Sheela; Møldrup, Per;

    2016-01-01

    The characterization of soil pore space geometry is important for explaining fluxes of air, water, and solutes through soil and understanding soil hydrogeochemical functions. X-ray computed tomography (CT) can be applied for this characterization, and in this study CT-derived parameters were used...... be factors that increased the uncertainty of the relationships. Nevertheless, the results confirmed the potential of X-ray CT visualization techniques for estimating fluxes through soil at the field scale....... to explain water, air, and solute transport through soil. Forty-five soil columns (20 by 20 cm) were collected from an agricultural field in Estrup, Denmark, and subsequently scanned using a medical CT scanner. Nonreactive tracer leaching experiments were performed in the laboratory along with measurements...

  1. X-ray CT for quantitative food microstructure engineering: The apple case

    Energy Technology Data Exchange (ETDEWEB)

    Herremans, Els, E-mail: els.herremans@biw.kuleuven.be [BIOSYST-MeBioS, KU Leuven, Willem de Croylaan 42, 3001 Leuven (Belgium); Verboven, Pieter; Defraeye, Thijs; Rogge, Seppe; Ho, Quang Tri; Hertog, Maarten L.A.T.M. [BIOSYST-MeBioS, KU Leuven, Willem de Croylaan 42, 3001 Leuven (Belgium); Verlinden, Bert E. [VCBT, Flanders Centre of Postharvest Technology, Willem de Croylaan 42, 3001 Leuven (Belgium); Bongaers, Evi [Bruker microCT, Kartuizersweg 3B, 2550 Kontich (Belgium); Wevers, Martine [MTM, KU Leuven, Kasteelpark Arenberg 44, 3001 Leuven (Belgium); Nicolai, Bart M. [BIOSYST-MeBioS, KU Leuven, Willem de Croylaan 42, 3001 Leuven (Belgium); VCBT, Flanders Centre of Postharvest Technology, Willem de Croylaan 42, 3001 Leuven (Belgium)

    2014-04-01

    Highlights: • Diffusivity of O{sub 2} and CO{sub 2} in Braeburn tissue were computed from X-ray micro-CT data. • Diffusivities were different for the distinct stages of ‘Braeburn’ browning disorder. • Microstructural gas transport constants were implemented in models of intact fruit. • We simulated internal O{sub 2} concentrations for longterm storage treatments of Braeburn. • This engineering approach can optimize internal quality of apple during CA storage. - Abstract: Apple fruit is a major crop that can be supplied year-round due to low temperature storage in a controlled atmosphere with a reduced oxygen concentration and an increased carbon dioxide concentration. The low temperature and dedicated gas concentration levels are designed to provide optimal conditions that prevent ripening while maintaining the fundamental respiratory metabolism necessary for energy supply in the cells that ensures cell and tissue integrity during storage of the fruit. If the concentration of oxygen is too low or that of carbon dioxide too high, a fermentation metabolism is induced that causes the production of off-flavours, results in insufficient energy supply, leading to cell collapse and consequent tissue browning and cavity formation. The microstructural arrangement of cells and intercellular spaces in the apple create specific pathways for transport of the respiratory gasses oxygen and carbon dioxide. We used X-ray CT to characterise the changes in the microstructure of ‘Braeburn’ apple during the development of internal storage disorders. Multiscale modeling was applied to understand the changes in oxygen and carbon dioxide concentrations and respiration and fermentation rates in the apple during the disorder development in controlled atmosphere storage of ‘Braeburn’ apple fruit. The 3D microstructure geometries of healthy, brown tissue and tissue with cavities were created to solve the micro-scale gas-exchange model for O{sub 2} and CO{sub 2} using the

  2. Analogue experiment of the crustal deformation by X-ray CT; X sen CT wo mochiita chikaku no henkei no analogue jikken

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Y.; Shi, B; Murakami, Y. [Geological Survey of Japan, Tsukuba (Japan)

    1997-05-27

    This paper reports a predictive result on a deformation experiment on sand beds using an X-ray computerized tomography (CT) equipment. The X-ray CT is a method to perform the following processes: X-rays are irradiated on a sample; decayed intensity data are measured along ray paths of the permeated X-rays; the data are inverted by using the Fourier transform; and spatial distribution of the coefficient of X-ray absorption inside the sample is acquired as a gray scale image. The deformation experiment was carried by putting sand into an acrylic container to a depth of 2 cm and manually pressing a plate in the horizontal direction. Sand blocks make a relative motion along a specific plane when they are deformed, but it was not possible to recognize faults clearly by naked eyes. Upon completion of the deformation, the experimental device was placed on the CT equipment to acquire images of the two-dimensional cross section. The higher the X-ray absorption coefficient, the brighter the picture elements. It can be seen that three inversed faults have been imaged clearly. Therefore, this equipment was verified usable as an effective observation equipment for an analogue deformation experiment. 4 refs., 2 figs.

  3. Early Detection of Amyloid Plaque in Alzheimer’s Disease Via X-ray Phase CT

    Science.gov (United States)

    2015-06-01

    to two reasons – (i) the fabrication/optimization of x-ray gratings were much more complicated and challenging than we initially anticipated and ( ii...Primarily due to two reasons – (i) the fabrication/optimization of x-ray gratings were much more complicated and challenging than we initially...re-optimization – Phase de-wrapping: Since x-ray grating fabrication is a complicated process, there inevitably exists imperfection in either grating

  4. Attempt at Visualizing Breast Cancer with X-ray Dark Field Imaging

    Science.gov (United States)

    Ando, Masami; Yamasaki, Katsuhito; Toyofuku, Fukai; Sugiyama, Hiroshi; Ohbayashi, Chiho; Li, Gang; Pan, Lin; Jiang, Xiaoming; Pattanasiriwisawa, Wanwisa; Shimao, Daisuke; Hashimoto, Eiko; Kimura, Tatsuro; Tsuneyoshi, Masazumi; Ueno, Ei; Tokumori, Kenji; Maksimenko, Anton; Higashida, Yoshiharu; Hirano, Masatsugu

    2005-04-01

    X-ray dark-field imaging (DFI) can clearly visualize breast cancer phantoms and cancer cell nests, stroma, fat tissue, ductus lactiferi, muscle, collagen fibers at stroma and calcification in a 2.8-mm-thick breast cancer pathological specimen. The system comprises a Bragg asymmetric-cut monochro-collimator and a 2.124-mm-thick Si 440 Laue diffraction analyzer at 35 keV. Both optical elements are Floating Zone made silicon crystals. The view size of 33 mm (H) × 19.5 mm (V) and the spatial resolution of 10 μm or better are obtainable at the vertical wiggler beamline BL14B at the Photon Factory.

  5. Three dimensional simulation of fluid flow in X-ray CT images of porous media

    Science.gov (United States)

    Al-Omari, A.; Masad, E.

    2004-11-01

    A numerical scheme is developed in order to simulate fluid flow in three dimensional (3-D) microstructures. The governing equations for steady incompressible flow are solved using the semi-implicit method for pressure-linked equations (SIMPLE) finite difference scheme within a non-staggered grid system that represents the 3-D microstructure. This system allows solving the governing equations using only one computational cell. The numerical scheme is verified through simulating fluid flow in idealized 3-D microstructures with known closed form solutions for permeability. The numerical factors affecting the solution in terms of convergence and accuracy are also discussed. These factors include the resolution of the analysed microstructure and the truncation criterion. Fluid flow in 2-D X-ray computed tomography (CT) images of real porous media microstructure is also simulated using this numerical model. These real microstructures include field cores of asphalt mixes, laboratory linear kneading compactor (LKC) specimens, and laboratory Superpave gyratory compactor (SGC) specimens. The numerical results for the permeability of the real microstructures are compared with the results from closed form solutions. Copyright

  6. Application of X-ray CT investigation of CO2-brine flow in porous media

    Science.gov (United States)

    Jiang, Lanlan; Liu, Yu; Song, Yongchen; Yang, Mingjun; Xue, Ziqiu; Zhao, Yuechao; Zhao, Jiafei; Zhang, Yi; Suekane, Tetsuya; Shen, Zijian

    2015-05-01

    A clear understanding of two-phase flows in porous media is important for investigating CO2 geological storage. In this study, we conducted an experiment of CO2/brine flow process in porous media under sequestration conditions using X-ray CT technique. The flow properties of relative permeability, porosity heterogeneity, and CO2 saturation were observed in this experiment. The porous media was packed with glass beads having a diameter of 0.2 mm. The porosity distribution along the flow direction is heterogeneous owing to the diameter and shape of glass beads along the flow direction. There is a relationship between CO2 saturation and porosity distribution, which changes with different flow rates and fractional flows. The heterogeneity of the porous media influences the distribution of CO2; moreover, gravity, fractional flows, and flow rates influence CO2 distribution and saturation. The relative permeability curve was constructed using the steady-state method. The results agreed well with the relative permeability curve simulated using pore-network model.

  7. Detection of intramyocardial fatty components in patients with cardiac disease by ultrafast X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Kaminaga, T. [Div. of Tracer Kinetics, Biomedical Research Center, Osaka Univ. Medical School, Suita (Japan); Naito, H. [Div. of Functional Diagnostic Imaging, Biomedical Research Center, Osaka Univ. Medical School, Suita (Japan); Takamiya, M. [Dept. of Radiology, National Cardiovascular Center, Suita, Osaka (Japan)

    1994-10-01

    To investigate intramyocardial fatty components as regards their distribution, frequency by disorder and cause, 331 patients with cardiac disease were examined with ultrafast X-ray CT (UFCT). The patient group consisted of 139 cases of myocardial infarction and angina, 27 cases of Kawasaki disease, 28 cases of hypertrophic cardiomyopathy (HCM), 22 cases of dilated cardiomyopathy (DCM), 3 cases of arrhythmogenic right ventricular dysplasia (ARVD), 40 cases of valvular disease, 33 cases of left ventricular hypertrophy due to hypertension, 17 cases of arrhythmia, 10 cases of cardiac sarcoidosis, 6 cases of myocarditis and 6 cases of congenital anomaly. Intramyocardial fatty components were detected in 15 patients (5 myocardial infarction, 2 Kawasaki disease, 3 HCM, 4 DCM, 1 ARVD). In patients with myocardial infarction, Kawasaki disease or DCM, the segments with fatty components agreed well with the segments with asynergy in left ventriculography and/or the segments with perfusion defects in thallium myocardial scintigraphy. The frequency of intramyocardial fatty components in each disease was initially determined as follows: 6% in myocardial infarction, 7% in Kawasaki disease, 11% in HCM and 18% in DCM. Ischaemic myocardial damage can induce intramyocardial fatty components in patients with myocardial infarction, Kawasaki disease or DCM. (orig.)

  8. X-ray CT Scanning Reveals Long-Term Copper Pollution Effects on Functional Soil Structure

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Møldrup, Per; Homstrup, Martin

    Soil structure plays the main role in the ability of the soil to fulfill essential soil functions such as the root growth, rate of water infiltration and retention, transport of gaseous and chemicals/pollutants through the soil. Soil structure is a dynamic soil property and affected by various...... factors such as soil type, land use, and soil contamination. In this study, we quantified the soil structure using X-ray CT scanning and revealed the effect of a long history of Copper (Cu) pollution on it. A fallow field at Hygum Denmark provides this opportunity as it had a long history of Copper...... sulphate contamination in a gradient with Cu content varies from 21 mg kg-1 to 3837 mg kg-1. Total 20 intact soil columns (diameter of 10 cm and height of 8 cm) were sampled at five locations along the Cu-gradient from a depth of 5 to 15 cm below surface level. The soil columns were scanned at a voxel...

  9. A dynamic micro-CT scanner based on a carbon nanotube field emission x-ray source.

    Science.gov (United States)

    Cao, G; Lee, Y Z; Peng, R; Liu, Z; Rajaram, R; Calderon-Colon, X; An, L; Wang, P; Phan, T; Sultana, S; Lalush, D S; Lu, J P; Zhou, O

    2009-04-21

    Current commercial micro-CT scanners have the capability of imaging objects ex vivo with high spatial resolution, but performing in vivo micro-CT on free-breathing small animals is still challenging because their physiological motions are non-periodic and much faster than those of humans. In this paper, we present a prototype physiologically gated micro-computed tomography (micro-CT) scanner based on a carbon nanotube field emission micro-focus x-ray source. The novel x-ray source allows x-ray pulses and imaging sequences to be readily synchronized and gated to non-periodic physiological signals from small animals. The system performance is evaluated using phantoms and sacrificed and anesthetized mice. Prospective respiratory-gated micro-CT images of anesthetized free-breathing mice were collected using this scanner at 50 ms temporal resolution and 6.2 lp mm(-1) at 10% system MTF. The high spatial and temporal resolutions of the micro-CT scanner make it well suited for high-resolution imaging of free-breathing small animals.

  10. X-ray phase contrast imaging of the breast: Analysis of tissue simulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Vedantham, Srinivasan; Karellas, Andrew [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States)

    2013-04-15

    Purpose: Phase contrast imaging, particularly of the breast, is being actively investigated. The purpose of this work is to investigate the x-ray phase contrast properties of breast tissues and commonly used breast tissue substitutes or phantom materials with an aim of determining the phantom materials best representative of breast tissues. Methods: Elemental compositions of breast tissues including adipose, fibroglandular, and skin were used to determine the refractive index, n= 1 -{delta}+i {beta}. The real part of the refractive index, specifically the refractive index decrement ({delta}), over the energy range of 5-50 keV were determined using XOP software (version 2.3, European Synchrotron Radiation Facility, France). Calcium oxalate and calcium hydroxyapatite were considered to represent the material compositions of microcalcifications in vivo. Nineteen tissue substitutes were considered as possible candidates to represent adipose tissue, fibroglandular tissue and skin, and four phantom materials were considered as possible candidates to represent microcalcifications. For each material, either the molecular formula, if available, or the elemental composition based on weight fraction, was used to determine {delta}. At each x-ray photon energy, the absolute percent difference in {delta} between the breast tissue and the substitute material was determined, from which three candidates were selected. From these candidate tissue substitutes, the material that minimized the absolute percent difference in linear attenuation coefficient {mu}, and hence {beta}, was considered to be best representative of that breast tissue. Results: Over the energy range of 5-50 keV, while the {delta} of CB3 and fibroglandular tissue-equivalent material were within 1% of that of fibroglandular tissue, the {mu} of fibroglandular tissue-equivalent material better approximated the fibroglandular tissue. While the {delta} of BR10 and adipose tissue-equivalent material were within 1% of

  11. Visualising, segmenting and analysing heterogenous glacigenic sediments using 3D x-ray CT.

    Science.gov (United States)

    Carr, Simon; Diggens, Lucy; Groves, John; O'Sullivan, Catherine; Marsland, Rhona

    2015-04-01

    Whilst there has been significant application of 3D x-ray CT to geological contexts, much of this work has focused on examining properties such as porosity, which are important in reservoir assessment and hydrological evaluations. There has been considerably less attention given to the analysis of the properties of sediments themselves. One particular challenge in CT analysis is to effectively observe and discriminate the relationships between the skeleton and matrix of a sediment. This is particularly challenging in glacial sediments, which comprise an admixture of particles of a wide range of size, morphology and composition within a variably-consolidated sediment body. A key sedimentological component of glacial sediments is their fabric properties. Till fabric data has long been applied to the analysis of the coupling between glaciers and their deformable substrates. This work has typically focused on identifying former ice-flow directions, processes of till deformation and emplacement, and such data is often used to reconcile the sedimentary evidence of former glaciation with the predicted glacier and ice-sheet dynamics derived from numerical models. The collection and interpretation of till fabric data has received significant criticism in recent years, with issues such as low sample populations (typically ~50 grains per sample), small-scale spatial variation in till fabric and operator bias during data collection, all of which compromise the reliability of macro-scale till fabric analysis. Recent studies of micro-scale till fabrics have substantially added to our understanding, and suggest there is systematic variation in particle fabric as a function of particle size. However, these findings are compromised by the 2D nature of the samples (derived from thin sections) capturing only apparent orientations of particles, and are again limited to relatively small datasets. As such, there are fundamental limitations in the quality and application of till fabric

  12. Non-invasive classification of breast microcalcifications using x-ray coherent scatter computed tomography

    Science.gov (United States)

    Ghammraoui, Bahaa; Popescu, Lucretiu M.

    2017-02-01

    We investigate the use of energy dispersive x-ray coherent scatter computed tomography (ED-CSCT) as a non-invasive diagnostic method to differentiate between type I and type II breast calcifications. This approach is sensitive to the differences of composition and internal crystal structure of different types of microcalcifications. The study is carried out by simulating a CSCT system with a scanning pencil beam, considering a polychromatic x-ray source and an energy-resolving photon counting detector. In a first step, the multidimensional angle and energy distributed CSCT data is reduced to the projection-space distributions of only a few components, corresponding to the expected target composition: adipose, glandular tissue, weddellite (calcium oxalate) for type I calcifications, and hydroxyapatite for type II calcifications. The maximum-likelihood estimation of scatter components algorithm used, operating in the projection space, takes into account the polychromatic source, the detector response function and the energy dependent attenuation. In the second step, component images are reconstructed from the corresponding estimated component projections using filtered backprojection. In a preliminary step the coherent scatter differential cross sections for hydroxyapatite and weddellite minerals were determined experimentally. The classification of type I or II calcifications is done using the relative contrasts of their components as the criterion. Simulation tests were carried out for different doses and energy resolutions for multiple realizations. The results were analyzed using relative/receiver operating characteristic methodology and show good discrimination ability at medium and higher doses. The noninvasive CSCT technique shows potential to further improve the breast diagnostic accuracy and reduce the number of breast biopsies.

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

    Science.gov (United States)

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

    1998-10-01

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

  14. Analysis of axial spatial resolution in a variable resolution x-ray cone beam CT (VRX-CBCT) system

    Science.gov (United States)

    Dahi, Bahram; Keyes, Gary S.; Rendon, David A.; DiBianca, Frank A.

    2008-03-01

    The Variable Resolution X-ray (VRX) technique has been successfully used in a Cone-Beam CT (CBCT) system to increase the spatial resolution of CT images in the transverse plane. This was achieved by tilting the Flat Panel Detector (FPD) to smaller vrx y angles in a VRX Cone Beam CT (VRX-CBCT) system. In this paper, the effect on the axial spatial resolution of CT images created by the VRX-CBCT system is examined at different vrx x angles, where vrx x is the tilting angle of the FPD about its x-axis. An amorphous silicon FPD with a CsI scintillator is coupled with a micro-focus x-ray tube to form a CBCT. The FPD is installed on a rotating frame that allows rotation of up to 90° about x and y axes of the FPD. There is no rotation about the z-axis (i.e. normal to the imaging surface). Tilting the FPD about its x-axis (i.e. decreasing the vrx x angle) reduces both the width of the line-spread function and the sampling distance by a factor of sin vrx x, thereby increasing the theoretical detector pre-sampling spatial resolution proportionately. This results in thinner CT slices that in turn help increase the axial spatial resolution of the CT images. An in-house phantom is used to measure the MTF of the reconstructed CT images at different vrx x angles.

  15. Comparison between X-rays spectra and their effective energies in small animal CT tomographic imaging and dosimetry.

    Science.gov (United States)

    Hamdi, Mahdjoub; Mimi, Malika; Bentourkia, M'hamed

    2016-12-22

    Small animal CT imaging and dosimetry usually rely on X-ray radiation produced by X-ray tubes. These X-rays typically cover a large energy range. In this study, we compared poly-energetic X-ray spectra against estimated equivalent (effective) mono-energetic beams with the same number of simulated photons for small animal CT imaging and dosimetry applications. Two poly-energetic X-ray spectra were generated from a tungsten anode at 50 and 120 kVp. The corresponding effective mono-energetic beams were established as 36 keV for the 50 kVp spectrum and 49.5 keV for the 120 kVp spectrum. To assess imaging applications, we investigated the spatial resolution by a tungsten wire, and the contrast-to-noise ratio in a reference phantom and in a realistic mouse phantom. For dosimetry investigation, we calculated the absorbed dose in a segmented digital mouse atlas in the skin, fat, heart and bone tissues. Differences of 2.1 and 2.6% in spatial resolution were respectively obtained between the 50 and 120 kVp poly-energetic spectra and their respective 36 and 49.5 keV mono-energetic beams. The differences in contrast-to-noise ratio between the poly-energetic 50 kVp spectrum and its corresponding mono-energetic 36 keV beam for air, fat, brain and bone were respectively -2.9, -0.2, 11.2 and -4.8%, and similarly between the 120 kVp and its effective energy 49.5 keV: -11.3, -20.2, -4.2 and -13.5%. Concerning the absorbed dose, for the lower X-ray beam energies, 50 kVp against 36 keV, the poly-energetic radiation doses were higher than the mono-energetic doses. Instead, for the higher X-ray beam energies, 120 kVp and 49.5 keV, the absorbed dose to the bones and lungs were higher for the mono-energetic 49.5 keV. The intensity and energy of the X-ray beam spectrum have an impact on both imaging and dosimetry in small animal studies. Simulations with mono-energetic beams should take into account these differences in order to study biological effects or to be compared to

  16. X-ray CT for quantitative food microstructure engineering: The apple case

    Science.gov (United States)

    Herremans, Els; Verboven, Pieter; Defraeye, Thijs; Rogge, Seppe; Ho, Quang Tri; Hertog, Maarten L. A. T. M.; Verlinden, Bert E.; Bongaers, Evi; Wevers, Martine; Nicolai, Bart M.

    2014-04-01

    Apple fruit is a major crop that can be supplied year-round due to low temperature storage in a controlled atmosphere with a reduced oxygen concentration and an increased carbon dioxide concentration. The low temperature and dedicated gas concentration levels are designed to provide optimal conditions that prevent ripening while maintaining the fundamental respiratory metabolism necessary for energy supply in the cells that ensures cell and tissue integrity during storage of the fruit. If the concentration of oxygen is too low or that of carbon dioxide too high, a fermentation metabolism is induced that causes the production of off-flavours, results in insufficient energy supply, leading to cell collapse and consequent tissue browning and cavity formation. The microstructural arrangement of cells and intercellular spaces in the apple create specific pathways for transport of the respiratory gasses oxygen and carbon dioxide. We used X-ray CT to characterise the changes in the microstructure of ‘Braeburn’ apple during the development of internal storage disorders. Multiscale modeling was applied to understand the changes in oxygen and carbon dioxide concentrations and respiration and fermentation rates in the apple during the disorder development in controlled atmosphere storage of ‘Braeburn’ apple fruit. The 3D microstructure geometries of healthy, brown tissue and tissue with cavities were created to solve the micro-scale gas-exchange model for O2 and CO2 using the finite volume method. The apparent gas diffusivities of the tissue were calculated and implemented in the macroscale geometry of healthy and disordered apples to study in detail the changes in the respiratory metabolism of the fruit.

  17. Comparison of the Ability of Various Imaging Modalities (CT & Plain X- Ray in Detecting Drug Transport in Body Packers

    Directory of Open Access Journals (Sweden)

    Morteza Sanei

    2009-01-01

    Full Text Available "ndrugs within the human body. In our country due to vast common border with Afghanistan which is the biggest Opium producer in the world and has the second place in Heroine production, drug smuggling has potential national threat and besides it has a global impact as using our territory as the major smuggling route to the west. Furthermore, in recent years new generations of African smugglers of new types of drugs are using our country as a transit route to transport drugs to Europe or Africa. In this way handmade or automatically produced packets are swallowed, rectally or vaginally inserted, and then transported. The first choice modality is plain x-ray of the abdomen in upright and supine positions. Recently abdominal and pelvic CT without contrast has shown a great success rate in the detection of body packers with changing window modality to detect different types of drugs. "nMaterials and Methods: Plain x-ray and abdominal and pelvic CT without contrast were performed for 12 cases who confessed to drug packet ingestion. The presence, number and location of the packets were evaluated in different modalities and the density of the packets were also measured in Hounsfield units (HU. "nResults: The mean age of our cases was 28.2±5.9 years (range, 17-35 years. Eleven (91.6 % patients were male and only one case was female. All patients had characteristic findings in plain x-ray and also all packets were visualized in all patients "nConclusion: Plain x-ray has a distinctive position in detecting packets in intestines especially when oral contrast materials are used. It is cheaper and more accessible than CT, but using different Hounsfield units in CT windows can even characterize different types of drugs even before extracting them.  

  18. Human breast cancer in vitro: matching histo-pathology with small-angle x-ray scattering and diffraction enhanced x-ray imaging

    Science.gov (United States)

    Fernández, Manuel; Keyriläinen, Jani; Serimaa, Ritva; Torkkeli, Mika; Karjalainen-Lindsberg, Marja-Liisa; Leidenius, Marjut; von Smitten, Karl; Tenhunen, Mikko; Fiedler, Stefan; Bravin, Alberto; Weiss, Thomas M.; Suortti, Pekka

    2005-07-01

    Twenty-eight human breast tumour specimens were studied with small-angle x-ray scattering (SAXS), and 10 of those were imaged by the diffraction enhanced x-ray imaging (DEI) technique. The sample diameter was 20 mm and the thickness 1 mm. Two examples of ductal carcinoma are illustrated by histology images, DEI, and maps of the collagen d-spacing and scattered intensity in the Porod regime, which characterize the SAXS patterns from collagen-rich regions of the samples. Histo-pathology reveals the cancer-invaded regions, and the maps of the SAXS parameters show that in these regions the scattering signal differs significantly from scattering by the surrounding tissue, indicating a degradation of the collagen structure in the invaded regions. The DEI images show the borders between collagen and adipose tissue and provide a co-ordinate system for tissue mapping by SAXS. In addition, degradation of the collagen structure in an invaded region is revealed by fading contrast of the DEI refraction image. The 28 samples include fresh, defrosted tissue and formalin-fixed tissue. The d-values with their standard deviations are given. In the fresh samples there is a systematic 0.76% increase of the d-value in the invaded regions, averaged over 11 samples. Only intra-sample comparisons are made for the formalin-fixed samples, and with a long fixation time, the difference in the d-value stabilizes at about 0.7%. The correspondence between the DEI images, the SAXS maps and the histo-pathology suggests that definitive information on tumour growth and malignancy is obtained by combining these x-ray methods.

  19. The evaluation of breast tissues removed during reductive mammaplasty with dual energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    De Lorenzo, Antonino [Division of Human Nutrition, University of Tor Vergata in Rome (Italy); Gravante, Gianpiero [Division of Human Nutrition, University of Tor Vergata in Rome (Italy); Department of Surgery, Whipps Cross University Hospital, London (United Kingdom)], E-mail: ggravante@hotmail.com; Sorge, Roberto [Laboratory of Biometry, University of Tor Vergata in Rome (Italy); Nicoli, Fabio; Caruso, Riccardo; Araco, Antonino [Department of Plastic Surgery, University of Tor Vergata in Rome (Italy); Servidio, Michele [Division of Human Nutrition, University of Tor Vergata in Rome (Italy); Orlandi, Augusto [Department of Biopathology, Anatomic Pathology Institute, University of Tor Vergata in Rome (Italy); Cervelli, Valerio [Department of Plastic Surgery, University of Tor Vergata in Rome (Italy)

    2009-06-15

    Purpose: We conducted a case-control study in which patients were evaluated with dual energy X-ray absorptiometry (DEXA) before and after breast reduction surgery, and results were correlated with the histological examination. Our goal was to confirm the DEXA as a precise technique for the measurement of breast composition, in order to propose it for the preoperative evaluation of plastic surgery patients. Materials and methods: We prospectively recruited all women that underwent reduction mammaplasty and excluded patients with contraindications to the operation or those that previously underwent bariatric surgery to reduce their weight. Patients were evaluated with DEXA 1 week before and after surgery. Results: From February to October 2006 we recruited 25 patients. The statistical analysis found a significant reduction of weight, BMI, regional fat free mass and fat mass after the operation. The comparison between DEXA and the histological analysis produced a correlation r = 0.989 (r{sup 2} = 0.978), with a predictivity of 98% and a percentage of error 8.3% (95% confidence intervals -252.6, 273.7; 95% limits of agreements of Bland and Altman -436.0, 457.1). Similar results were obtained with the analysis of fat. Conclusions: Our study demonstrated that conventional segmental DEXA is a very precise technique to measure the amount of tissue removed in breast reductions and could open future application in the preoperative assessment of patients undergoing such operations.

  20. In-situ X-ray CT results of damage evolution in L6 ordinary chondrite meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Cuadra, Jefferson A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hazeli, Kavan [Univ. of Alabama, Huntsville, AL (United States); Ramesh, K. T. [Johns Hopkins Univ., Baltimore, MD (United States). Hopkins Extreme Materials Inst.; Martz, Harry [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Nondestructive Characterization Inst.

    2016-06-17

    These are slides about in-situ X-ray CT results of damage evolution in L6 ordinary chondrite meteorites. The following topics are covered: mechanical and thermal damage characterization, list of Grosvenor Mountain (GRO) meteorite samples, in-situ x-ray compression test setup, GRO-chipped reference at 0 N - existing cracks, GRO-chipped loaded at 1580 N, in-situ x-ray thermal fatigue test setup, GRO-B14 room temperature reference, GRO-B14 Cycle 47 at 200°C, GRO-B14 Cycle 47 at room temperature, conclusions from qualitative analysis, future work and next steps. Conclusions are the following: Both GRO-Chipped and GRO-B14 had existing voids and cracks within the volume. These sites with existing damage were selected for CT images from mechanically and thermally loaded scans since they are prone to damage initiation. The GRO-Chipped sample was loaded to 1580 N which resulted in a 14% compressive engineering strain, calculated using LVDT. Based on the CT cross sectional images, the GRO-B14 sample at 200°C has a thermal expansion of approximately 96 μm in height (i.e. ~1.6% engineering strain).

  1. Fatigue damage observed non-destructively in fibre composite coupon test specimens by X-ray CT

    Science.gov (United States)

    Jespersen, K. M.; Mikkelsen, L. P.

    2016-07-01

    This study presents a method for monitoring the 3D fatigue damage progression on a micro-structural level in a glass fibre/polymer coupon test specimen by means of laboratory X-ray Computed Tomography (CT). A modified mount and holder made for the standard test samples to fit into the X-ray CT scanner along with a tension clamp solution is presented. Initially, the same location of the test specimen is inspected by ex-situ X-ray CT during the fatigue loading history, which shows the damage progression on a micro-structural level. The openings of individual uni-directional (UD) fibre fractures are seen to generally increase with the number of cycles, and new regions of UD fibre fractures also appear. There are some UD fibre fractures that are difficult to detect since their opening is small. Therefore, the effect of tension on the crack visibility is examined afterwards using a tension clamp solution. With applied tension some additional cracks become visible and the openings of fibre fractures increases, which shows the importance of applied tension during the scan.

  2. Prediction of biopore- and matrix-dominated flow from X-ray CT-derived macropore network characteristics

    Science.gov (United States)

    Naveed, Muhammad; Moldrup, Per; Schaap, Marcel G.; Tuller, Markus; Kulkarni, Ramaprasad; Vogel, Hans-Jörg; Wollesen de Jonge, Lis

    2016-10-01

    Prediction and modeling of localized flow processes in macropores is of crucial importance for sustaining both soil and water quality. However, currently there are no reliable means to predict preferential flow due to its inherently large spatial variability. The aim of this study was to investigate the predictive performance of previously developed empirical models for both water and air flow and to explore the potential applicability of X-ray computed tomography (CT)-derived macropore network characteristics. For this purpose, 65 cylindrical soil columns (6 cm diameter and 3.5 cm height) were extracted from the topsoil (5 cm to 8.5 cm depth) in a 15 m × 15 m grid from an agricultural field located in Silstrup, Denmark. All soil columns were scanned with an industrial X-ray CT scanner (129 µm resolution) and later employed for measurement of saturated hydraulic conductivity, air permeability at -30 and -100 cm matric potential, and gas diffusivity at -30 and -100 cm matric potential. Distribution maps for saturated hydraulic conductivity, air permeability, and gas diffusivity reflected no autocorrelation irrespective of soil texture and organic matter content. Existing empirical predictive models for saturated hydraulic conductivity and air permeability showed poor performance, as they were not able to realistically capture macropore flow. The tested empirical model for gas diffusivity predicted measurements at -100 cm matric potential reasonably well, but failed at -30 cm matric potential, particularly for soil columns with biopore-dominated flow. X-ray CT-derived macroporosity matched the measured air-filled porosity at -30 cm matric potential well. Many of the CT-derived macropore network characteristics were strongly interrelated. Most of the macropore network characteristics were also significantly correlated with saturated hydraulic conductivity, air permeability, and gas diffusivity. The predictive Ahuja et al. (1984) model for saturated hydraulic

  3. Comparative study with CT and plain X-ray film on the diagnosis of interstitial pulmonary diseases of patients with rheumatoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Masahiko; Adachi, Shuji; Tanaka, Koji; Shimizu, Tadafumi; Hirota, Shozo; Sako, Masao; Kono, Michio; Imura, Shigeaki.

    1989-01-01

    In order to detect the interstitial pulmonary disease of rheumatoid arthritis (RA), we studied 91 patients with RA and compared the appearances of high resolution CT with those of plain chest X-ray film. We found 43 cases of interstitial pneumonitis on CT. We classified the CT and X-ray appearances as 4 groups (0-3) based on the degrees of pulmonary lesions. The both classifications accorded only in 46 cases (51%). In 46 cases who were not detected any changes by plain X-ray film, 17 were detected interstitial changes by CT. As to the early interstitial changes, the detectability of CT was superior to that of plain X-ray film.

  4. Volumetric soft tissue brain imaging on xCAT, a mobile flat-panel x-ray CT system

    Science.gov (United States)

    Zbijewski, Wojciech; Stayman, J. Webster

    2009-02-01

    We discuss the ongoing development of soft-tissue imaging capabilities on xCAT, a highly portable, flat-panel based cone-beam X-ray CT platform. By providing the ability to rapidly detect intra-cranial bleeds and other symptoms of stroke directly at the patient's bedside, our new system can potentially significantly improve the management of neurological emergency and intensive care patients. The paper reports on the design of our system, as well as on the methods used to combat artifacts due to scatter, non-linear detector response and scintillator glare. Images of cadaveric head samples are also presented and compared with conventional CT scans.

  5. Experimental assessment of the influence of beam hardening filters on image quality and patient dose in volumetric 64-slice X-ray CT scanners

    NARCIS (Netherlands)

    Ay, Mohammad Reza; Mehranian, Abolfazi; Maleki, Asghar; Ghadiri, Hossien; Ghafarian, Pardis; Zaidi, Habib

    2013-01-01

    Beam hardening filters have long been employed in X-ray Computed Tomography (CT) to preferentially absorb soft and low-energy X-rays having no or little contribution to image formation, thus allowing the reduction of patient dose and beam hardening artefacts. In this work, we studied the influence o

  6. Breast tissue classification using x-ray scattering measurements and multivariate data analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Elaine A; Farquharson, Michael J [School of Allied Health Sciences, City University, Charterhouse Square, London EC1M 6PA (United Kingdom)

    2007-11-21

    This study utilized two radiation scatter interactions in order to differentiate malignant from non-malignant breast tissue. These two interactions were Compton scatter, used to measure the electron density of the tissues, and coherent scatter to obtain a measure of structure. Measurements of these parameters were made using a laboratory experimental set-up comprising an x-ray tube and HPGe detector. The breast tissue samples investigated comprise five different tissue classifications: adipose, malignancy, fibroadenoma, normal fibrous tissue and tissue that had undergone fibrocystic change. The coherent scatter spectra were analysed using a peak fitting routine, and a technique involving multivariate analysis was used to combine the peak fitted scatter profile spectra and the electron density values into a tissue classification model. The number of variables used in the model was refined by finding the sensitivity and specificity of each model and concentrating on differentiating between two tissues at a time. The best model that was formulated had a sensitivity of 54% and a specificity of 100%.

  7. Breast tissue classification using x-ray scattering measurements and multivariate data analysis

    Science.gov (United States)

    Ryan, Elaine A.; Farquharson, Michael J.

    2007-11-01

    This study utilized two radiation scatter interactions in order to differentiate malignant from non-malignant breast tissue. These two interactions were Compton scatter, used to measure the electron density of the tissues, and coherent scatter to obtain a measure of structure. Measurements of these parameters were made using a laboratory experimental set-up comprising an x-ray tube and HPGe detector. The breast tissue samples investigated comprise five different tissue classifications: adipose, malignancy, fibroadenoma, normal fibrous tissue and tissue that had undergone fibrocystic change. The coherent scatter spectra were analysed using a peak fitting routine, and a technique involving multivariate analysis was used to combine the peak fitted scatter profile spectra and the electron density values into a tissue classification model. The number of variables used in the model was refined by finding the sensitivity and specificity of each model and concentrating on differentiating between two tissues at a time. The best model that was formulated had a sensitivity of 54% and a specificity of 100%.

  8. Engineering iodine-doped carbon dots as dual-modal probes for fluorescence and X-ray CT imaging.

    Science.gov (United States)

    Zhang, Miaomiao; Ju, Huixiang; Zhang, Li; Sun, Mingzhong; Zhou, Zhongwei; Dai, Zhenyu; Zhang, Lirong; Gong, Aihua; Wu, Chaoyao; Du, Fengyi

    2015-01-01

    X-ray computed tomography (CT) is the most commonly used imaging technique for noninvasive diagnosis of disease. In order to improve tissue specificity and prevent adverse effects, we report the design and synthesis of iodine-doped carbon dots (I-doped CDs) as efficient CT contrast agents and fluorescence probe by a facile bottom-up hydrothermal carbonization process. The as-prepared I-doped CDs are monodispersed spherical nanoparticles (a diameter of ~2.7 nm) with favorable dispersibility and colloidal stability in water. The aqueous solution of I-doped CDs showed wavelength-dependent excitation and stable photoluminescence similar to traditional carbon quantum dots. Importantly, I-doped CDs displayed superior X-ray attenuation properties in vitro and excellent biocompatibility. After intravenous injection, I-doped CDs were distributed throughout the body and excreted by renal clearance. These findings validated that I-doped CDs with high X-ray attenuation potency and favorable photoluminescence show great promise for biomedical research and disease diagnosis.

  9. Cardiac motion correction based on partial angle reconstructed images in x-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seungeon; Chang, Yongjin; Ra, Jong Beom, E-mail: jbra@kaist.ac.kr [Department of Electrical Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2015-05-15

    Purpose: Cardiac x-ray CT imaging is still challenging due to heart motion, which cannot be ignored even with the current rotation speed of the equipment. In response, many algorithms have been developed to compensate remaining motion artifacts by estimating the motion using projection data or reconstructed images. In these algorithms, accurate motion estimation is critical to the compensated image quality. In addition, since the scan range is directly related to the radiation dose, it is preferable to minimize the scan range in motion estimation. In this paper, the authors propose a novel motion estimation and compensation algorithm using a sinogram with a rotation angle of less than 360°. The algorithm estimates the motion of the whole heart area using two opposite 3D partial angle reconstructed (PAR) images and compensates the motion in the reconstruction process. Methods: A CT system scans the thoracic area including the heart over an angular range of 180° + α + β, where α and β denote the detector fan angle and an additional partial angle, respectively. The obtained cone-beam projection data are converted into cone-parallel geometry via row-wise fan-to-parallel rebinning. Two conjugate 3D PAR images, whose center projection angles are separated by 180°, are then reconstructed with an angular range of β, which is considerably smaller than a short scan range of 180° + α. Although these images include limited view angle artifacts that disturb accurate motion estimation, they have considerably better temporal resolution than a short scan image. Hence, after preprocessing these artifacts, the authors estimate a motion model during a half rotation for a whole field of view via nonrigid registration between the images. Finally, motion-compensated image reconstruction is performed at a target phase by incorporating the estimated motion model. The target phase is selected as that corresponding to a view angle that is orthogonal to the center view angles of

  10. Characterization of a Test for Invasive Breast Cancer Using X-ray Diffraction of Hair - Results of a Clinical Trial

    Directory of Open Access Journals (Sweden)

    Gary L. Corino

    2009-11-01

    Full Text Available Objective: To assess the performance of a test for breast cancer utilizing synchrotron x-ray diffraction analysis of scalp hair from women undergoing diagnostic radiology assessment. Design and Setting: A double-blinded clinical trial of women who attended diagnostic radiology clinics in Australia. Patients: 1796 women referred for diagnostic radiology, with no previous history of cancer. Main Outcome Measures: Sensitivity, specificity and accuracy of the hair test analysis compared to the gold standard of imaging followed by biopsy where indicated. Results: The hair-based assay had an overall accuracy of >77% and a negative predictive value of 99%. For all women, the sensitivity of both mammography and x-ray diffraction alone was 64%, but when used together the sensitivity rose to 86%. The sensitivity of the hair test for women under the age of 70 was 74%. Conclusion: In this large population trial the association between the presence of breast cancer and an altered hair fibre X-ray diffraction pattern previously reported has been confirmed. It appears that mammography and X-ray diffraction of hair detect different populations of breast cancers, and are synergistic when used together.

  11. Mobile 3D rotational X-ray: comparison with CT in sinus surgery

    Energy Technology Data Exchange (ETDEWEB)

    Carelsen, B. [Dept. of Medical Physics, Academic Medical Center, Amsterdam (Netherlands); Bakker, N.H. [Dept. of Man-Machine Systems, Delft Univ. of Technology, Delft (Netherlands); Boon, S.N. [General X-ray Surgery, Philips Medical Systems, Best (Netherlands); Fokkens, W.J. [ENT Dept., Academic Medical Center, Amsterdam (Netherlands); Freling, N.J.M. [Radiology Dept., Academic Medical Center, Amsterdam (Netherlands); Noordhoek, N.J. [X-ray Pre-development, Philips Medical Systems, Best (Netherlands)

    2004-11-01

    Clinical evaluation of a 3D rotational X-ray (3D-RX) system, comprising a modified Philips BV Pulsera C-arm system and a Philips 3D-RA workstation, demonstrates good diagnostic accuracy in functional endoscopic sinus surgery.

  12. X-ray phase-contrast tomosynthesis for improved breast tissue discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Schleede, Simone, E-mail: Schleede@tum.de [Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany); Bech, Martin, E-mail: martin.bech@tum.de [Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany); Medical Radiation Physics, Lund University, 22185 Lund (Sweden); Grandl, Susanne, E-mail: Susanne.Grandl@med.uni-muenchen.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München (Germany); Sztrókay, Aniko, E-mail: Aniko.Sztrokay@med.uni-muenchen.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München (Germany); Herzen, Julia, E-mail: julia.herzen@hzg.de [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Mayr, Doris, E-mail: doris.mayr@med.uni-muenchen.de [Institute of Pathology, Ludwig-Maximilians-Universität München, Thalkirchner Str. 36, 80337 Munich (Germany); Stockmar, Marco, E-mail: marco.stockmar@ph.tum.de [Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany); Potdevin, Guillaume, E-mail: potdevinguillaume@gmail.com [Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany); and others

    2014-03-15

    Purpose: Attenuation-based tomosynthesis has proven to successfully resolve the glandular tissue overlap present in mammography. However, the ability of tomosynthesis to differentiate tumorous and glandular tissue remains limited, due to the small differences in X-ray attenuation in breast tissue. One possibility to overcome this limitation and to further increase the diagnostic value of tomosynthesis exams, is the application of recently developed grating-based phase-contrast methods, which provide complementary information on the phase shift and the local scattering power of the sample. In this study, we report on first phase-contrast breast tomosynthesis results of a mastectomy sample slice with an invasive ductal carcinoma. Material and methods: A slice of a mastectomy sample with histologically proven invasive ductal cancer was imaged at the synchrotron radiation source ESRF (Grenoble, France). We used a two-grating interferometer setup at the ninth fractional Talbot distance and with an X-ray energy of 23 keV. In grating interferometry absorption, differential phase, and scattering images are recorded simultaneously. The tomosynthesis scan comprises 61 projections. Multimodal tomosynthesis results were reconstructed using a standard filtered back-projection approach. Our findings are supported by a comparison of tomographic views to histopathology. Results: Phase-contrast tomosynthesis combines the advantage of improved soft-tissue discrimination in phase-contrast imaging with the ability of tomosynthesis to provide a third dimension so that improved feature visibility is not hampered by superposition artifacts. Our results indicate superior diagnostic value due to the depth resolution supplied in tomosynthesis imaging; a region of necrotic tissue that is obscured in a projection image can clearly be depicted in one single tomosynthesis slice. Compared to absorption tomosynthesis alone, soft tissue contrast is significantly enhanced in phase

  13. Soil pore characteristics assessed from X-ray micro-CT derived images and correlations to soil friability

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Heck, R; Deen, B

    2012-01-01

    -rayCT scanner and link then these results to soilfriabilityassessed using the drop shatter method. Minimally disturbed soil cores were taken from selected treatments in a long-term rotation and tillage treatment experiment located on a silt loam at the Elora Research Station near Elora, Ontario, Canada. Soil......X-ray computed tomography (CT) scanning technology has, in recent decades, been shown to be a very powerful technique to visualize and quantify soil structure. The objective of this project was to quantify soilporecharacteristics, on undisturbed field moist soil, using a high resolution X...... cores varied in porosity and porecharacteristics. A drop shatter test was used as a reference procedure to quantify soilfriability. The top 40 mm of the 80 mm high soil samples were scanned using a X-raymicro-CT scanner. The selected region of interest (36 × 36 × 36 mm) was reconstructed with a voxel...

  14. Spectral X-Ray CT Image Reconstruction with a Combination of Energy-Integrating and Photon-Counting Detectors.

    Directory of Open Access Journals (Sweden)

    Qingsong Yang

    Full Text Available The purpose of this paper is to develop an algorithm for hybrid spectral computed tomography (CT which combines energy-integrating and photon-counting detectors. While the energy-integrating scan is global, the photon-counting scan can have a local field of view (FOV. The algorithm synthesizes both spectral data and energy-integrating data. Low rank and sparsity prior is used for spectral CT reconstruction. An initial estimation is obtained from the projection data based on physical principles of x-ray interaction with the matter, which provides a more accurate Taylor expansion than previous work and can guarantee the convergence of the algorithm. Numerical simulation with clinical CT images are performed. The proposed algorithm produces very good spectral features outside the FOV when no K-edge material exists. Exterior reconstruction of K-edge material can be partially achieved.

  15. Spectral X-Ray CT Image Reconstruction with a Combination of Energy-Integrating and Photon-Counting Detectors.

    Science.gov (United States)

    Yang, Qingsong; Cong, Wenxiang; Xi, Yan; Wang, Ge

    2016-01-01

    The purpose of this paper is to develop an algorithm for hybrid spectral computed tomography (CT) which combines energy-integrating and photon-counting detectors. While the energy-integrating scan is global, the photon-counting scan can have a local field of view (FOV). The algorithm synthesizes both spectral data and energy-integrating data. Low rank and sparsity prior is used for spectral CT reconstruction. An initial estimation is obtained from the projection data based on physical principles of x-ray interaction with the matter, which provides a more accurate Taylor expansion than previous work and can guarantee the convergence of the algorithm. Numerical simulation with clinical CT images are performed. The proposed algorithm produces very good spectral features outside the FOV when no K-edge material exists. Exterior reconstruction of K-edge material can be partially achieved.

  16. Evolution of spatial resolution in breast CT at UC Davis

    Energy Technology Data Exchange (ETDEWEB)

    Gazi, Peymon M. [Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, California 95616 (United States); Yang, Kai [Department of Radiological Sciences, University of Oklahoma Health Sciences Center, 940 N.E. 13th Street, Nicholson Tower, Oklahoma City, Oklahoma 73104 (United States); Burkett, George W.; Aminololama-Shakeri, Shadi [Department of Radiology, University of California, Davis Medical Center, 4860 Y Street, Suite 3100 Ellison Building, Sacramento, California 95817 (United States); Anthony Seibert, J.; Boone, John M., E-mail: john.boone@ucdmc.ucdavis.edu [Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, California 95616 and Department of Radiology, University of California, Davis Medical Center, 4860 Y Street, Suite 3100 Ellison Building, Sacramento, California 95817 (United States)

    2015-04-15

    Purpose: Dedicated breast computed tomography (bCT) technology for the purpose of breast cancer screening has been a focus of research at UC Davis since the late 1990s. Previous studies have shown that improvement in spatial resolution characteristics of this modality correlates with greater microcalcification detection, a factor considered a potential limitation of bCT. The aim of this study is to improve spatial resolution as characterized by the modulation transfer function (MTF) via changes in the scanner hardware components and operational schema. Methods: Four prototypes of pendant-geometry, cone-beam breast CT scanners were designed and developed spanning three generations of design evolution. To improve the system MTF in each bCT generation, modifications were made to the imaging components (x-ray tube and flat-panel detector), system geometry (source-to-isocenter and detector distance), and image acquisition parameters (technique factors, number of projections, system synchronization scheme, and gantry rotational speed). Results: Characterization of different generations of bCT systems shows these modifications resulted in a 188% improvement of the limiting MTF properties from the first to second generation and an additional 110% from the second to third. The intrinsic resolution degradation in the azimuthal direction observed in the first generation was corrected by changing the acquisition from continuous to pulsed x-ray acquisition. Utilizing a high resolution detector in the third generation, along with modifications made in system geometry and scan protocol, resulted in a 125% improvement in limiting resolution. An additional 39% improvement was obtained by changing the detector binning mode from 2 × 2 to 1 × 1. Conclusions: These results underscore the advancement in spatial resolution characteristics of breast CT technology. The combined use of a pulsed x-ray system, higher resolution flat-panel detector and changing the scanner geometry and image

  17. Quantitative X-ray CT analysis of calcification of the abdominal aorta and its relationship to obesity

    Energy Technology Data Exchange (ETDEWEB)

    Shinagawa, Toshio; Hiraiwa, Yoshio; Mizuno, Seio; Kusunoki, Norio; Nitta, Yu; Matsubara, Takao; Iwainaka, Yoichi; Konishi, Hideo (Toyama Red Cross Hospital (Japan))

    1992-04-01

    Quantitative analysis of abdominal aorta calcification by X-ray CT is useful method for non-invasive diagnosis of atherosclerosis. We recently examined the relationship between the X-ray CT measurement of abdominal aorta calcification and the degree of obesity. For this purpose, the body mass index (BMI) and the subcutaneous fat thickness (determined by X-ray CT at the umbilical level) were analyzed in relation to the abdominal aorta calcification index (ACI) in 845 patients (453 males and 392 females aged 40-79 years). Patients with BMI under 20 were classified as 'lean', those with BMI between 20-26 as 'normal' and those with BMI over 26 as 'obese'. 1. Among males, the ACI was highest in lean individuals and lowest in obese individuals. The difference in ACI between lean and obese males was significant in the middle aged group (40-65 years). Among females, no relationship was observed between the degree of obesity and ACI. 2. Among males, ACI was higher in individuals with low subcutaneous fat thickness and lower in individuals with greater subcutaneous fat thickness. The difference was significant in the middle aged group. Among females, no relationship was observed between the two parameters. 3. When the visceral fat to subcutaneous fat ratio (V/S) in 85 males and females aged 60-69 years was analyzed in relation to ACI, ACI tended to decrease as the V/S increased, in both males and females. 4. Relationships between BMI and subcutaneous fat thickness, between BMI and lipids and between lipids and ACI were also analyzed. (author).

  18. Engineering iodine-doped carbon dots as dual-modal probes for fluorescence and X-ray CT imaging

    Directory of Open Access Journals (Sweden)

    Zhang M

    2015-11-01

    Full Text Available Miaomiao Zhang,1,* Huixiang Ju,2,* Li Zhang,1,* Mingzhong Sun,2 Zhongwei Zhou,2 Zhenyu Dai,3 Lirong Zhang,1 Aihua Gong,1 Chaoyao Wu,1 Fengyi Du1 1School of Medicine, Jiangsu University, Zhenjiang, People’s Republic of China; 2Department of Clinical Laboratory, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, Jiangsu, People’s Republic of China; 3Radiology Department, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, Jiangsu, People’s Republic of China *These authors contributed equally to this work Abstract: X-ray computed tomography (CT is the most commonly used imaging technique for noninvasive diagnosis of disease. In order to improve tissue specificity and prevent adverse effects, we report the design and synthesis of iodine-doped carbon dots (I-doped CDs as efficient CT contrast agents and fluorescence probe by a facile bottom-up hydrothermal carbonization process. The as-prepared I-doped CDs are monodispersed spherical nanoparticles (a diameter of ~2.7 nm with favorable dispersibility and colloidal stability in water. The aqueous solution of I-doped CDs showed wavelength-dependent excitation and stable photoluminescence similar to traditional carbon quantum dots. Importantly, I-doped CDs displayed superior X-ray attenuation properties in vitro and excellent biocompatibility. After intravenous injection, I-doped CDs were distributed throughout the body and excreted by renal clearance. These findings validated that I-doped CDs with high X-ray attenuation potency and favorable photoluminescence show great promise for biomedical research and disease diagnosis. Keywords: carbon dots, contrast agents, iodine-doped, CT imaging

  19. Twin robotic x-ray system for 2D radiographic and 3D cone-beam CT imaging

    Science.gov (United States)

    Fieselmann, Andreas; Steinbrener, Jan; Jerebko, Anna K.; Voigt, Johannes M.; Scholz, Rosemarie; Ritschl, Ludwig; Mertelmeier, Thomas

    2016-03-01

    In this work, we provide an initial characterization of a novel twin robotic X-ray system. This system is equipped with two motor-driven telescopic arms carrying X-ray tube and flat-panel detector, respectively. 2D radiographs and fluoroscopic image sequences can be obtained from different viewing angles. Projection data for 3D cone-beam CT reconstruction can be acquired during simultaneous movement of the arms along dedicated scanning trajectories. We provide an initial evaluation of the 3D image quality based on phantom scans and clinical images. Furthermore, initial evaluation of patient dose is conducted. The results show that the system delivers high image quality for a range of medical applications. In particular, high spatial resolution enables adequate visualization of bone structures. This system allows 3D X-ray scanning of patients in standing and weight-bearing position. It could enable new 2D/3D imaging workflows in musculoskeletal imaging and improve diagnosis of musculoskeletal disorders.

  20. Determination of liquid's molecular interference function based on X-ray diffraction and dual-energy CT in security screening.

    Science.gov (United States)

    Zhang, Li; YangDai, Tianyi

    2016-08-01

    A method for deriving the molecular interference function (MIF) of an unknown liquid for security screening is presented. Based on the effective atomic number reconstructed from dual-energy computed tomography (CT), equivalent molecular formula of the liquid is estimated. After a series of optimizations, the MIF and a new effective atomic number are finally obtained from the X-ray diffraction (XRD) profile. The proposed method generates more accurate results with less sensitivity to the noise and data deficiency of the XRD profile.

  1. Three-dimensional modeling and simulation of asphalt concrete mixtures based on X-ray CT microstructure images

    Directory of Open Access Journals (Sweden)

    Hainian Wang

    2014-02-01

    Full Text Available X-ray CT (computed tomography was used to scan asphalt mixture specimen to obtain high resolution continuous cross-section images and the meso-structure. According to the theory of three-dimensional (3D reconstruction, the 3D reconstruction algorithm was investigated in this paper. The key to the reconstruction technique is the acquisition of the voxel positions and the relationship between the pixel element and node. Three-dimensional numerical model of asphalt mixture specimen was created by a self-developed program. A splitting test was conducted to predict the stress distributions of the asphalt mixture and verify the rationality of the 3D model.

  2. X-ray absorption microtomography (microCT) and small beam diffraction mapping of sea urchin teeth.

    Science.gov (United States)

    Stock, S R; Barss, J; Dahl, T; Veis, A; Almer, J D

    2002-07-01

    Two noninvasive X-ray techniques, laboratory X-ray absorption microtomography (microCT) and X-ray diffraction mapping, were used to study teeth of the sea urchin Lytechinus variegatus. MicroCT revealed low attenuation regions at near the tooth's stone part and along the carinar process-central prism boundary; this latter observation appears to be novel. The expected variation of Mg fraction x in the mineral phase (calcite, Ca(1-x)Mg(x)CO(3)) cannot account for all of the linear attenuation coefficient decrease in the two zones: this suggested that soft tissue is localized there. Transmission diffraction mapping (synchrotron X-radiation, 80.8 keV, 0.1 x 0.1mm(2) beam area, 0.1mm translation grid, image plate area detector) simultaneously probed variations in 3-D and showed that the crystal elements of the "T"-shaped tooth were very highly aligned. Diffraction patterns from the keel (adaxial web) and from the abaxial flange (containing primary plates and the stone part) differed markedly. The flange contained two populations of identically oriented crystal elements with lattice parameters corresponding to x=0.13 and x=0.32. The keel produced one set of diffraction spots corresponding to the lower x. The compositions were more or less equivalent to those determined by others for camarodont teeth, and the high Mg phase is expected to be disks of secondary mineral epitaxially related to the underlying primary mineral element. Lattice parameter gradients were not noted in the keel or flange. Taken together, the microCT and diffraction results indicated that there was a band of relatively high protein content, of up to approximately 0.25 volume fraction, in the central part of the flange and paralleling its adaxial and abaxial faces. X-ray microCT and microdiffraction data used in conjunction with protein distribution data will be crucial for understanding the properties of various biocomposites and their mechanical functions.

  3. Improved Scatter Correction in X-Ray Cone Beam CT with Moving Beam Stop Array Using Johns' Equation

    CERN Document Server

    Yan, Hao; Tang, Shaojie; Xu, Qiong

    2014-01-01

    In this paper, an improved scatter correction with moving beam stop array (BSA) for x-ray cone beam (CB) CT is proposed. Firstly, correlation between neighboring CB views is deduced based on John's Equation. Then, correlation-based algorithm is presented to complement the incomplete views by using the redundancy (over-determined information) in CB projections. Finally, combining the algorithm with scatter correction method using moving BSA, where part of primary radiation is blocked and incomplete projections are acquired, an improved correction method is proposed. Effectiveness and robustness is validated by Monte Carlo (MC) simulation with EGSnrc on humanoid phantom.

  4. Microscale electromagnetic heating in heterogeneous energetic materials based on X-ray CT imaging

    CERN Document Server

    Kort-Kamp, W J M; Ionita, A; Glover, B B; Duque, A L Higginbotham; Perry, W L; Patterson, B M; Dalvit, D A R; Moore, D S

    2015-01-01

    Electromagnetic stimulation of energetic materials provides a noninvasive and nondestructive tool for detecting and identifying explosives. We combine structural information based on X-ray computed tomography, experimental dielectric data, and electromagnetic full-wave simulations, to study microscale electromagnetic heating of realistic three-dimensional heterogeneous explosives. We analyze the formation of electromagnetic hot spots and thermal gradients in the explosive-binder meso-structures, and compare the heating rate for various binder systems.

  5. Synchrotron radiation phase-contrast X-ray CT imaging of acupuncture points

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dongming; Yan, Xiaohui; Zhang, Xinyi [Fudan University, Synchrotron Radiation Research Center, State Key Laboratory of Surface Physics and Department of Physics, Shanghai (China); Liu, Chenglin [Physics Department of Yancheng Teachers' College, Yancheng (China); Dang, Ruishan [The Second Military Medical University, Shanghai (China); Xiao, Tiqiao [Chinese Academy of Sciences, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Shanghai (China); Zhu, Peiping [Chinese Academy of Sciences, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Beijing (China)

    2011-08-15

    Three-dimensional (3D) topographic structures of acupuncture points were investigated by using synchrotron radiation in-line X-ray phase contrast computerized tomography. Two acupuncture points, named Zhongji (RN3) and Zusanli (ST36), were studied. We found an accumulation of microvessels at each acupuncture point region. Images of the tissues surrounding the acupuncture points do not show such kinds of structure. This is the first time that 3D images have revealed the specific structures of acupuncture points. (orig.)

  6. Application of Small Angle X-ray Scattering (SAXS for Differentiation between Normal and Cancerous Breast Tissue

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available Introduction: Small angle, between 3° and 10°, X ray scattering is predominantly coherent giving rise to diffraction effects that can be observed as constructive and destructive interferences. These interferences carry information about the molecular structure of the tissue and hence can be used to identify changes that occur due to cancer. Method: In this study an energy dispersive X-ray diffraction method was used. The optimum scattering angle, determined from a series of measurements on adipose breast tissue at several angles from 4 to 7.3 degrees, was found to be 6.5°. Once optimized the system was used to measure the diffraction profiles (corrected scattered intensity versus momentum transfer of a total of 99 breast tissue samples. The samples were both normal and tumour samples. Results: Adipose tissue showed a sharp, high intensity peak at low momentum transfer values of approximately 1.1nm-1. Adipose tissue, mixed tissue (adipose & fibroglandular and tumor have peaks at different values of momentum transfer that can be used to identify the tissue. Benign and malignant breast tissues can also be differentiated by both peak positions and peak heights. It was also observed that the results were reproducible even after the tissue had been preserved at liquid nitrogen temperatures. Conclusion: We were able to differentiate between normal, benign and malignant breast tissues by using energy dispersive small angle x-ray scattering.

  7. Characterizing X-ray detectors for prototype digital breast tomosynthesis systems

    Science.gov (United States)

    Kim, Y.-s.; Park, H.-s.; Park, S.-J.; Choi, S.; Lee, H.; Lee, D.; Choi, Y.-W.; Kim, H.-J.

    2016-03-01

    The digital breast tomosynthesis (DBT) system is a newly developed 3-D imaging technique that overcomes the tissue superposition problems of conventional mammography. Therefore, it produces fewer false positives. In DBT system, several parameters are involved in image acquisition, including geometric components. A series of projections should be acquired at low exposure. This makes the system strongly dependent on the detector's characteristic performance. This study compares two types of x-ray detectors developed by the Korea Electrotechnology Research Institute (KERI). The first prototype DBT system has a CsI (Tl) scintillator/CMOS based flat panel digital detector (2923 MAM, Dexela Ltd.), with a pixel size of 0.0748 mm. The second uses a-Se based direct conversion full field detector (AXS 2430, analogic) with a pixel size of 0.085 mm. The geometry of both systems is same, with a focal spot 665.8 mm from the detector, and a center of rotation 33 mm above the detector surface. The systems were compared with regard to modulation transfer function (MTF), normalized noise power spectrum (NNPS), detective quantum efficiency (DQE) and a new metric, the relative object detectability (ROD). The ROD quantifies the relative performance of each detector at detecting specified objects. The system response function demonstrated excellent linearity (R2>0.99). The CMOS-based detector had a high sensitivity, while the Anrad detector had a large dynamic range. The higher MTF and noise power spectrum (NPS) values were measured using an Anrad detector. The maximum DQE value of the Dexela detector was higher than that of the Anrad detector with a low exposure level, considering one projection exposure for tomosynthesis. Overall, the Dexela detector performed better than did the Anrad detector with regard to the simulated Al wires, spheres, test objects of ROD with low exposure level. In this study, we compared the newly developed prototype DBT system with two different types of x-ray

  8. X-ray attenuation of adipose breast tissue: in-vitro and in-vivo measurements using spectral imaging

    Science.gov (United States)

    Fredenberg, Erik; Erhard, Klaus; Berggren, Karl; Dance, David R.; Young, Kenneth C.; Cederström, Björn; Johansson, Henrik; Lundqvist, Mats; Moa, Elin; Homan, Hanno; Willsher, Paula; Kilburn-Toppin, Fleur; Wallis, Matthew

    2015-03-01

    The development of new x-ray imaging techniques often requires prior knowledge of tissue attenuation, but the sources of such information are sparse. We have measured the attenuation of adipose breast tissue using spectral imaging, in vitro and in vivo. For the in-vitro measurement, fixed samples of adipose breast tissue were imaged on a spectral mammography system, and the energy-dependent x-ray attenuation was measured in terms of equivalent thicknesses of aluminum and poly-methyl methacrylate (PMMA). For the in-vivo measurement, a similar procedure was applied on a number of spectral screening mammograms. The results of the two measurements agreed well and were consistent with published attenuation data and with measurements on tissue-equivalent material.

  9. Automatic quantification of mammary glands on non-contrast x-ray CT by using a novel segmentation approach

    Science.gov (United States)

    Zhou, Xiangrong; Kano, Takuya; Cai, Yunliang; Li, Shuo; Zhou, Xinxin; Hara, Takeshi; Yokoyama, Ryujiro; Fujita, Hiroshi

    2016-03-01

    This paper describes a brand new automatic segmentation method for quantifying volume and density of mammary gland regions on non-contrast CT images. The proposed method uses two processing steps: (1) breast region localization, and (2) breast region decomposition to accomplish a robust mammary gland segmentation task on CT images. The first step detects two minimum bounding boxes of left and right breast regions, respectively, based on a machine-learning approach that adapts to a large variance of the breast appearances on different age levels. The second step divides the whole breast region in each side into mammary gland, fat tissue, and other regions by using spectral clustering technique that focuses on intra-region similarities of each patient and aims to overcome the image variance caused by different scan-parameters. The whole approach is designed as a simple structure with very minimum number of parameters to gain a superior robustness and computational efficiency for real clinical setting. We applied this approach to a dataset of 300 CT scans, which are sampled with the equal number from 30 to 50 years-old-women. Comparing to human annotations, the proposed approach can measure volume and quantify distributions of the CT numbers of mammary gland regions successfully. The experimental results demonstrated that the proposed approach achieves results consistent with manual annotations. Through our proposed framework, an efficient and effective low cost clinical screening scheme may be easily implemented to predict breast cancer risk, especially on those already acquired scans.

  10. Application of micron X-ray CT based on micro-PIXE to investigate the distribution of Cs in silt particles for environmental remediation in Fukushima Prefecture

    Science.gov (United States)

    Ishii, Keizo; Hatakeyama, Taisuke; Itoh, Shin; Sata, Daichi; Ohnuma, Tohru; Yamaguchi, Toshiro; Arai, Hiromu; Arai, Hirotsugu; Matsuyama, Shigeo; Terakawa, Atsuki; Kim, Seong-Yun

    2016-03-01

    We used X-ray computed tomography (CT) using characteristic X-rays produced in micro-particle-induced X-ray emission (PIXE) to investigate the internal structure of silt particles and develop new methods to decontaminate soil containing radioactive cesium. We obtained 3D attenuation coefficient images of silt particles with a diameter of approximately 100 μm for V K and Cr K X-rays. Owing to the absorption edges of the Cs L-shell, the differences between the V K and Cr K X-ray images revealed the spatial distribution of Cs atoms in the silt particles. Cs atoms were distributed over the surfaces of the silt particles to a thickness of approximately 10 μm. This information is useful for the decontamination of silt contaminated by radiation from the Fukushima Daiichi nuclear disaster.

  11. Application of micron X-ray CT based on micro-PIXE to investigate the distribution of Cs in silt particles for environmental remediation in Fukushima Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Keizo, E-mail: keizo.ishii@qse.tohoku.ac.jp [Research Center for Remediation Engineering of Environments Contaminated with Radioisotopes, Graduate School of Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Hatakeyama, Taisuke; Itoh, Shin; Sata, Daichi [Department of Quantum Science and Energy Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Ohnuma, Tohru; Yamaguchi, Toshiro; Arai, Hiromu; Arai, Hirotsugu [Research Center for Remediation Engineering of Environments Contaminated with Radioisotopes, Graduate School of Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Matsuyama, Shigeo; Terakawa, Atsuki; Kim, Seong-Yun [Department of Quantum Science and Energy Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan)

    2016-03-15

    We used X-ray computed tomography (CT) using characteristic X-rays produced in micro-particle-induced X-ray emission (PIXE) to investigate the internal structure of silt particles and develop new methods to decontaminate soil containing radioactive cesium. We obtained 3D attenuation coefficient images of silt particles with a diameter of approximately 100 μm for V K and Cr K X-rays. Owing to the absorption edges of the Cs L-shell, the differences between the V K and Cr K X-ray images revealed the spatial distribution of Cs atoms in the silt particles. Cs atoms were distributed over the surfaces of the silt particles to a thickness of approximately 10 μm. This information is useful for the decontamination of silt contaminated by radiation from the Fukushima Daiichi nuclear disaster.

  12. Towards respiration management in radiation treatment of lung tumors: transferring regions of interest from planning CT to kilovoltage X-ray images.

    Science.gov (United States)

    Ataer-Cansizoglu, Esra; Bas, Erhan; Yousuf, M; You, Sheng; D'Souza, Warren D; Erdogmus, Deniz

    2010-01-01

    Tracking of lung tumors is imperative for improved radiotherapy treatment. However, the motion of the thoracic organs makes it a complicated task. 4D CT images acquired prior to treatment provide valuable information regarding the motion of organs and tumor, since it is manually annotated. In order to track tumors using treatment-day X-ray images (kV images), we need to find the correspondence with CT images so that projection of tumor region of interest will provide a good estimate about the position of the tumor on the X-ray image. In this study, we propose a method to estimate the alignment and respiration phase corresponding to X-ray images using 4D CT data. Our approach generates Digitally Reconstructed Radiographs (DRRs) using bilateral filter smoothing and computes rigid registration with kV images since the position and orientation of patient might differ between CT and treatment-day image acquisition processes. Instead of using landmark points, our registration method makes use of Kernel Density Estimation over the edges that are not affected much by respiration. To estimate the phase of X-ray, we apply template matching techniques between the lung regions of X-ray and registered DRRs. Our approach gives accurate results for rigid registration and provides a starting point to track tumors using the X-ray images during the treatment.

  13. Methane hydrate distribution from prolonged and repeated formation in natural and compacted sand samples: X-ray CT observations

    Energy Technology Data Exchange (ETDEWEB)

    Rees, E.V.L.; Kneafsey, T.J.; Seol, Y.

    2010-07-01

    To study physical properties of methane gas hydrate-bearing sediments, it is necessary to synthesize laboratory samples due to the limited availability of cores from natural deposits. X-ray computed tomography (CT) and other observations have shown gas hydrate to occur in a number of morphologies over a variety of sediment types. To aid in understanding formation and growth patterns of hydrate in sediments, methane hydrate was repeatedly formed in laboratory-packed sand samples and in a natural sediment core from the Mount Elbert Stratigraphic Test Well. CT scanning was performed during hydrate formation and decomposition steps, and periodically while the hydrate samples remained under stable conditions for up to 60 days. The investigation revealed the impact of water saturation on location and morphology of hydrate in both laboratory and natural sediments during repeated hydrate formations. Significant redistribution of hydrate and water in the samples was observed over both the short and long term.

  14. Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part I. Morphology.

    Science.gov (United States)

    Scarlett, Nicola Vivienne Yorke; Tyson, Peter; Fraser, Darren; Mayo, Sheridan; Maksimenko, Anton

    2016-07-01

    Synchrotron X-ray tomography has been applied to the study of titanium parts fabricated by additive manufacturing (AM). The AM method employed here was the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V), as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. Samples were chosen to examine the effect of build direction and complexity of design on the surface morphology and final dimensions of the piece.

  15. Early Detection of Amyloid Plaque in Alzheimer’s Disease via X-ray Phase CT

    Science.gov (United States)

    2016-08-01

    developed an algorithm to significantly reduce, if not eliminate, the artifacts caused by the phenomenon of twin peaks, as shown in Fig. 5 (c... algorithm ” Med. Phys., 28(3): 812-25, 2001. 4. X Wu and H Liu, “Clinical implementation of x-ray phase-contrast imaging: Theoretical foundations and...k), spectrum of noise equivalent quanta NEQ(k), and detective quantum efficiency DQE(k). A cylindrical water phantom at 5.1 mm diameter and complex

  16. 2D and 3D Terahertz Imaging and X-Rays CT for Sigillography Study

    Science.gov (United States)

    Fabre, M.; Durand, R.; Bassel, L.; Recur, B.; Balacey, H.; Bou Sleiman, J.; Perraud, J.-B.; Mounaix, P.

    2017-04-01

    Seals are part of our cultural heritage but the study of these objects is limited because of their fragility. Terahertz and X-Ray imaging are used to analyze a collection of wax seals from the fourteenth to eighteenth centuries. In this work, both techniques are compared in order to discuss their advantages and limits and their complementarity for conservation state study of the samples. Thanks to 3D analysis and reconstructions, defects and fractures are detected with an estimation of their depth position. The path from the parchment tongue inside the seals is also detected.

  17. Effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies

    Science.gov (United States)

    Murase, Kenya; Nanjo, Takafumi; Satoshi, Ii; Miyazaki, Shohei; Hirata, Masaaki; Sugawara, Yoshifumi; Kudo, Masayuki; Sasaki, Kousuke; Mochizuki, Teruhito

    2005-11-01

    The purpose of this study was to investigate the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using multi-detector row CT (MDCT). Following the standard CT perfusion study protocol, continuous (cine) scans (1 s/rotation × 60 s) consisting of four 5 mm thick contiguous slices were performed using an MDCT scanner with a tube voltage of 80 kVp and a tube current of 200 mA. We generated the simulated images with tube currents of 50 mA, 100 mA and 150 mA by adding the corresponding noise to the raw scan data of the original image acquired above using a noise simulation tool. From the original and simulated images, we generated the functional images of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in seven patients with cerebrovascular disease, and compared the correlation coefficients (CCs) between the perfusion parameter values obtained from the original and simulated images. The coefficients of variation (CVs) in the white matter were also compared. The CC values deteriorated with decreasing tube current. There was a significant difference between 50 mA and 100 mA for all perfusion parameters. The CV values increased with decreasing tube current. There were significant differences between 50 mA and 100 mA and between 100 mA and 150 mA for CBF. For CBV and MTT, there was also a significant difference between 150 mA and 200 mA. This study will be useful for understanding the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using MDCT, and for selecting the tube current.

  18. X-ray tube-based diffraction enhanced imaging prototype images of full-thickness breast specimens: reader study evaluation

    Science.gov (United States)

    Faulconer, L. S.; Parham, C.; Connor, D. J.; Koomen, M.; Kuzmiak, C.; Pavic, D.; Livasy, C. A.; Kim, E.; Zeng, D.; Cole, E. B.; Zhong, Z.; Pisano, E. D.

    2009-02-01

    Conventional mammographic image contrast is derived from x-ray absorption, resulting in breast structure visualization due to density gradients that attenuate radiation without distinction between transmitted and scattered or refracted x-rays. This leads to image blurring and contrast reduction, hindering the early detection of small or otherwise occult cancers. Diffraction enhanced imaging (DEI) allows for dramatically increased contrast with decreased radiation dose compared to conventional mammographic imaging due to monochromatic x-rays, its unique refraction-based contrast mechanism and excellent scatter rejection. However, a lingering drawback to the clinical translation of DEI has been the requirement for synchrotron radiation. Our laboratory developed a DEI prototype (DEI-PR) utilizing a readily available Tungsten xray tube source and traditional DEI crystal optics, providing soft tissue images at 60keV. To demonstrate the clinical utility of our DEI-PR, we acquired images of full-thickness human breast tissue specimens on synchrotron-based DEI, DEI-PR and digital mammography systems. A reader study was designed to allow unbiased assessment of system performance when analyzing three systems with dissimilar imaging parameters and requiring analysis of images unfamiliar to radiologists. A panel of expert radiologists evaluated lesion feature visibility and histopathology correlation after receiving training on the interpretation of refraction contrast mammographic images. Preliminary data analysis suggests that our DEI system performed roughly equivalently with the traditional DEI system, demonstrating a significant step toward clinical translation of this modality for breast cancer applications.

  19. X-ray Diagnosis of Breast Cancer%乳腺癌的X线诊断分析

    Institute of Scientific and Technical Information of China (English)

    王涛

    2015-01-01

    Objective To investigate the X-ray diagnosis of breast cancer patients analyzed. Methods A retrospective analysis of X-ray ifndings of our hospital in 2012 and 2014 were treated 22 cases of breastcancer patients. Results The performance of breast lumps shadow, tumor calcification, nipple retraction, skin thickening, thickening of the vein. Conclusion X-ray examination is the main diagnostic tool in breast cancer.%目的 探讨乳腺癌患者的X线诊断分析.方法回顾性分析我院2012年~2014年收治的22例乳腺癌患者的X线表现.结果 乳腺癌的表现为肿块阴影、肿瘤钙化、乳头凹陷、皮肤增厚、静脉增粗.结论 X线平片是检查乳腺癌主要诊断手段.

  20. CT-guided brachytherapy of prostate cancer: reduction of effective dose from X-ray examination

    Science.gov (United States)

    Sanin, Dmitriy B.; Biryukov, Vitaliy A.; Rusetskiy, Sergey S.; Sviridov, Pavel V.; Volodina, Tatiana V.

    2014-03-01

    Computed tomography (CT) is one of the most effective and informative diagnostic method. Though the number of CT scans among all radiographic procedures in the USA and European countries is 11% and 4% respectively, CT makes the highest contribution to the collective effective dose from all radiographic procedures, it is 67% in the USA and 40% in European countries [1-5]. Therefore it is necessary to understand the significance of dose value from CT imaging to a patient . Though CT dose from multiple scans and potential risk is of great concern in pediatric patients, this applies to adults as well. In this connection it is very important to develop optimal approaches to dose reduction and optimization of CT examination. International Commission on Radiological Protection (ICRP) in its publications recommends radiologists to be aware that often CT image quality is higher than it is necessary for diagnostic confidence[6], and there is a potential to reduce the dose which patient gets from CT examination [7]. In recent years many procedures, such as minimally invasive surgery, biopsy, brachytherapy and different types of ablation are carried out under guidance of computed tomography [6;7], and during a procedures multiple CT scans focusing on a specific anatomic region are performed. At the Clinics of MRRC different types of treatment for patients with prostate cancer are used, incuding conformal CT-guided brachytherapy, implantation of microsources of I into the gland under guidance of spiral CT [8]. So, the purpose of the study is to choose optimal method to reduce radiation dose from CT during CT-guided prostate brachytherapy and to obtain the image of desired quality.

  1. Dual-energy X-ray micro-CT imaging of hybrid Ni/Al open-cell foam

    Science.gov (United States)

    Fíla, T.; Kumpová, I.; Koudelka, P.; Zlámal, P.; Vavřík, D.; Jiroušek, O.; Jung, A.

    2016-01-01

    In this paper, we employ dual-energy X-ray microfocus tomography (DECT) measurement to develop high-resolution finite element (FE) models that can be used for the numerical assessment of the deformation behaviour of hybrid Ni/Al foam subjected to both quasi-static and dynamic compressive loading. Cubic samples of hybrid Ni/Al open-cell foam with an edge length of [15]mm were investigated by the DECT measurement. The material was prepared using AlSi7Mg0.3 aluminium foam with a mean pore size of [0.85]mm, coated with nanocrystalline nickel (crystallite size of approx. [50]nm) to form a surface layer with a theoretical thickness of [0.075]mm. CT imaging was carried out using state-of-the-art DSCT/DECT X-ray scanner developed at Centre of Excellence Telč. The device consists of a modular orthogonal assembly of two tube-detector imaging pairs, with an independent geometry setting and shared rotational stage mounted on a complex 16-axis CNC positioning system to enable unprecedented measurement variability for highly-detailed tomographical measurements. A sample of the metal foam was simultaneously irradiated using an XWT-240-SE reflection type X-ray tube and an XWT-160-TCHR transmission type X-ray tube. An enhanced dual-source sampling strategy was used for data acquisition. X-ray images were taken using XRD1622 large area GOS scintillator flat panel detectors with an active area of [410 × 410]mm and resolution [2048 × 2048]pixels. Tomographic scanning was performed in 1,200 projections with a 0.3 degree angular step to improve the accuracy of the generated models due to the very complex microstructure and high attenuation of the investigated material. Reconstructed data was processed using a dual-energy algorithm, and was used for the development of a 3D model and voxel model of the foam. The selected parameters of the models were compared with nominal parameters of the actual foam and showed good correlation.

  2. Archaeometric studies by neutron, x-ray radiography and microCT

    Science.gov (United States)

    Latini, R. M.; Bellido, A. V. B.; Vinagre Filho, U. M.; Souza, M. I. S.; Lima, I.; Oliveira, D. F.; Lopes, R. T.

    2013-05-01

    The aim of this study is to investigate manufacturing techniques used in prehistoric Brazilian pottery from Acre state and Araruama, Rio de Janeiro state, Brazil, using Neutron and X-Ray Radiography. For the neutrongraphy different fragments of pottery were submitted to a neutron flux of the order of 105n.cm-2.s-1 for 3 minutes at the Argonauta research reactor of the Instituto de Engenharia Nuclear (IEN)/CNEN. Digital processing techniques using imaging plate were applied to process the image of the selected sample. For the radiography the sample were exposed to an X-Rays in the Feinfocus Model FX100 and the image was obtained by Flat Panel GE IT Model DXR 250V at the Laboratório de Instrumentação Nuclear (LIN) - COPPE/UFRJ. The Neutrongraphy and radiography shows two different manufacturing details: palette and rollers and the microtomography shows cavities in the clay body and different temper applied in the pottery production. The preliminary results shows promising techniques applied for the pottery manufacturing information and as complement for better understanding the ceramics classification and precedence.

  3. Measurement of breast-tissue x-ray attenuation by spectral mammography: first results on cyst fluid

    Science.gov (United States)

    Fredenberg, Erik; Dance, David R.; Willsher, Paula; Moa, Elin; von Tiedemann, Miriam; Young, Kenneth C.; Wallis, Matthew G.

    2013-12-01

    Knowledge of x-ray attenuation is essential for developing and evaluating x-ray imaging technologies. For instance, techniques to better characterize cysts at mammography screening would be highly desirable to reduce recalls, but the development is hampered by the lack of attenuation data for cysts. We have developed a method to measure x-ray attenuation of tissue samples using a prototype photon-counting spectral mammography unit. The method was applied to measure the attenuation of 50 samples of breast cyst fluid and 50 samples of water. Spectral (energy-resolved) images of the samples were acquired and the image signal was mapped to equivalent thicknesses of two known reference materials, which can be used to derive the x-ray attenuation as a function of energy. The attenuation of cyst fluid was found to be significantly different from water. There was a relatively large natural spread between different samples of cyst fluid, whereas the homogeneity of each individual sample was found to be good; the variation within samples did not reach above the quantum noise floor. The spectral method proved stable between several measurements on the same sample. Further, chemical analysis and elemental attenuation calculation were used to validate the spectral measurement on a subset of the samples. The two methods agreed within the precision of the elemental attenuation calculation over the mammographic energy range.

  4. Maximum-likelihood estimation of scatter components algorithm for x-ray coherent scatter computed tomography of the breast

    Science.gov (United States)

    Ghammraoui, Bahaa; Badal, Andreu; Popescu, Lucretiu M.

    2016-04-01

    Coherent scatter computed tomography (CSCT) is a reconstructive x-ray imaging technique that yields the spatially resolved coherent-scatter cross section of the investigated object revealing structural information of tissue under investigation. In the original CSCT proposals the reconstruction of images from coherently scattered x-rays is done at each scattering angle separately using analytic reconstruction. In this work we develop a maximum likelihood estimation of scatter components algorithm (ML-ESCA) that iteratively reconstructs images using a few material component basis functions from coherent scatter projection data. The proposed algorithm combines the measured scatter data at different angles into one reconstruction equation with only a few component images. Also, it accounts for data acquisition statistics and physics, modeling effects such as polychromatic energy spectrum and detector response function. We test the algorithm with simulated projection data obtained with a pencil beam setup using a new version of MC-GPU code, a Graphical Processing Unit version of PENELOPE Monte Carlo particle transport simulation code, that incorporates an improved model of x-ray coherent scattering using experimentally measured molecular interference functions. The results obtained for breast imaging phantoms using adipose and glandular tissue cross sections show that the new algorithm can separate imaging data into basic adipose and water components at radiation doses comparable with Breast Computed Tomography. Simulation results also show the potential for imaging microcalcifications. Overall, the component images obtained with ML-ESCA algorithm have a less noisy appearance than the images obtained with the conventional filtered back projection algorithm for each individual scattering angle. An optimization study for x-ray energy range selection for breast CSCT is also presented.

  5. Maximum-likelihood estimation of scatter components algorithm for x-ray coherent scatter computed tomography of the breast.

    Science.gov (United States)

    Ghammraoui, Bahaa; Badal, Andreu; Popescu, Lucretiu M

    2016-04-21

    Coherent scatter computed tomography (CSCT) is a reconstructive x-ray imaging technique that yields the spatially resolved coherent-scatter cross section of the investigated object revealing structural information of tissue under investigation. In the original CSCT proposals the reconstruction of images from coherently scattered x-rays is done at each scattering angle separately using analytic reconstruction. In this work we develop a maximum likelihood estimation of scatter components algorithm (ML-ESCA) that iteratively reconstructs images using a few material component basis functions from coherent scatter projection data. The proposed algorithm combines the measured scatter data at different angles into one reconstruction equation with only a few component images. Also, it accounts for data acquisition statistics and physics, modeling effects such as polychromatic energy spectrum and detector response function. We test the algorithm with simulated projection data obtained with a pencil beam setup using a new version of MC-GPU code, a Graphical Processing Unit version of PENELOPE Monte Carlo particle transport simulation code, that incorporates an improved model of x-ray coherent scattering using experimentally measured molecular interference functions. The results obtained for breast imaging phantoms using adipose and glandular tissue cross sections show that the new algorithm can separate imaging data into basic adipose and water components at radiation doses comparable with Breast Computed Tomography. Simulation results also show the potential for imaging microcalcifications. Overall, the component images obtained with ML-ESCA algorithm have a less noisy appearance than the images obtained with the conventional filtered back projection algorithm for each individual scattering angle. An optimization study for x-ray energy range selection for breast CSCT is also presented.

  6. Comparative aspects of occult intrasacral meningocele with conventional X-ray, myelography and CT

    Energy Technology Data Exchange (ETDEWEB)

    Grivegnee, A.; Delince, P.; Ectors, P.

    1981-09-01

    A case of occult intrasacral meningocele is reported and the diagnostic reliability of conventional roentgenography, myelography and CT for the management of this rare lesions are evaluated. Probably, CT with the use of an intrathecal contrast agent could yield the most complete information about the precise nature of this cystic congenital dysraphism.

  7. Synchrotron X-ray studies of the keel of the short-spined sea urchin Lytechinus variegatus: absorption microtomography (microCT) and small beam diffraction mapping.

    Science.gov (United States)

    Stock, S R; Barss, J; Dahl, T; Veis, A; Almer, J D; Carlo, F

    2003-05-01

    In sea urchin teeth, the keel plays an important structural role, and this paper reports results of microstructural characterization of the keel of Lytechinus variegatus using two noninvasive synchrotron x-ray techniques: x-ray absorption microtomography (microCT) and x-ray diffraction mapping. MicroCT with 14 keV x-rays mapped the spatial distribution of mineral at the 1.3 microm level in a millimeter-sized fragment of a mature portion of the keel. Two rows of low absorption channels (i.e., primary channels) slightly less than 10 microm in diameter were found running linearly from the flange to the base of the keel and parallel to its sides. The primary channels paralleled the oral edge of the keel, and the microCT slices revealed a planar secondary channel leading from each primary channel to the side of the keel. The primary and secondary channels were more or less coplanar and may correspond to the soft tissue between plates of the carinar process. Transmission x-ray diffraction with 80.8 keV x-rays and a 0.1 mm beam mapped the distribution of calcite crystal orientations and the composition Ca(1-x)Mg(x)CO(3) of the calcite. Unlike the variable Mg concentration and highly curved prisms found in the keel of Paracentrotus lividus, a constant Mg content (x = 0.13) and relatively little prism curvature was found in the keel of Lytechinus variegatus.

  8. Image-based spectral distortion correction for photon-counting x-ray detectors

    OpenAIRE

    Ding, Huanjun; Molloi, Sabee

    2012-01-01

    Purpose: To investigate the feasibility of using an image-based method to correct for distortions induced by various artifacts in the x-ray spectrum recorded with photon-counting detectors for their application in breast computed tomography (CT).

  9. Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part II. Defects.

    Science.gov (United States)

    Scarlett, Nicola Vivienne Yorke; Tyson, Peter; Fraser, Darren; Mayo, Sheridan; Maksimenko, Anton

    2016-07-01

    Synchrotron X-ray tomography (SXRT) has been applied to the study of defects within three-dimensional printed titanium parts. These parts were made using the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V) as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. The samples represent a selection of complex shapes with a variety of internal morphologies. Inspection via SXRT has revealed a number of defects which may not otherwise have been seen. The location and nature of such defects combined with detailed knowledge of the process conditions can contribute to understanding the interplay between design and manufacturing strategy. This fundamental understanding may subsequently be incorporated into process modelling, prediction of properties and the development of robust methodologies for the production of defect-free parts.

  10. X-Ray CT of Highly-Attenuating Objects: 9- or 15- MV Spectra?

    Energy Technology Data Exchange (ETDEWEB)

    Stone, G; Trebes, J; Perry, R; Schneberk, D; Logan, C

    2005-08-29

    We imaged-highly attenuating test objects in three dimensions with 9-MV (at LLNL) and 15-MV (at Hill Air Force Base) x-ray spectra. While we used the same detector and motion control, there were differences that we could not control in the two radiography bays and in the sources. The results show better spatial resolution for the 9-MV spectrum and better contrast for the 15-MV spectrum. The 15-MV data contains a noise pattern that obfuscates the data. It is our judgment that if sufficient attention were given to design of the bay, beam dump, collimation, filtration and linac spot size; a 15-MV imaging system using a flat panel could be developed with spatial resolution of 5 lp/mm and contrastive performance better than we have demonstrated using a 9-MV spectrum.

  11. Noninvasive Detection of Coronary Artery Stenosis Using 16-slice Spiral CT: a Comparison with Selective X-ray Coronary Angiography

    Institute of Scientific and Technical Information of China (English)

    SHI Heshui; HAN Ping; KONG Xiangquan; FENG Gansheng; Martin HK Hoffmann

    2006-01-01

    The role of 16-slice spiral CT was evaluated in the diagnosis of coronary stenosis, with selective X-ray coronary angiography (SCA) serving as the reference standard. Sixty-five patients who were suspected of having coronary heart disease, without percutaneous transluminal coronary angioplasty or coronary bypass-grafting, were investigated using 16-slice CT. Eight patients with pre-scan heart rate of more than 80 beats/min were given β-blockers. After the retrospectively ECG-gated axial imaging reconstruction, volume redering (VR), multi-planar reconstruction (MPR), curved MPR and maximum intensity projection (MIP) were used to reconstruct. Every segment of coronary artery with a diameter ≥1.5 mm was assessed, and the presence on CT with a stenosis exceeding 50% diameter reduction was compared with that on SCA. The reasons which lead to some segments unevaluable were analysed. Compared with SCA, 93% coronary segments and 94 % main branches were evaluable. Residual cardiac motion artifacts, severe calcification and poor opacification made 58%, 28% and 14% of the remaining 60 segments unevaluable respectively. Without routine administration of β-blockers, good coronary imaging quality can be acquired using 16-slice spiral CT. It is a reliable noninvasive method for detection of obstructive coronary artery disease.

  12. Cortical region of interest definition on SPECT brain images using X-ray CT registration

    Energy Technology Data Exchange (ETDEWEB)

    Tzourio, N.; Sutton, D. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot); Joliot, M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot INSERM, Orsay (France)); Mazoyer, B.M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot Antenne d' Information Medicale, C.H.U. Bichat, Paris (France)); Charlot, V. (Hopital Louis Mourier, Colombes (France). Service de Psychiatrie); Salamon, G. (CHU La Timone, Marseille (France). Service de Neuroradiologie)

    1992-11-01

    We present a method for brain single photon emission computed tomography (SPECT) analysis based on individual registration of anatomical (CT) and functional ([sup 133]Xe regional cerebral blood flow) images and on the definition of three-dimensional functional regions of interest. Registration of CT and SPECT is performed through adjustment of CT-defined cortex limits to the SPECT image. Regions are defined by sectioning a cortical ribbon on the CT images, copied over the SPECT images and pooled through slices to give 3D cortical regions of interest. The proposed method shows good intra- and interobserver reproducibility (regional intraclass correlation coefficient [approx equal]0.98), and good accuracy in terms of repositioning ([approx equal]3.5 mm) as compared to the SPECT image resolution (14 mm). The method should be particularly useful for analysing SPECT studies when variations in brain anatomy (normal or abnormal) must be accounted for. (orig.).

  13. Quantifying Admissible Undersampling for Sparsity-Exploiting Iterative Image Reconstruction in X-Ray CT

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Heide; Sidky, Emil Y.; Pan, Xiaochuan

    2013-01-01

    Iterative image reconstruction with sparsity-exploiting methods, such as total variation (TV) minimization, investigated in compressive sensing claim potentially large reductions in sampling requirements. Quantifying this claim for computed tomography (CT) is nontrivial, because both full sampling...

  14. Modeling of body tissues for Monte Carlo simulation of radiotherapy treatments planned with conventional x-ray CT systems

    Science.gov (United States)

    Kanematsu, Nobuyuki; Inaniwa, Taku; Nakao, Minoru

    2016-07-01

    In the conventional procedure for accurate Monte Carlo simulation of radiotherapy, a CT number given to each pixel of a patient image is directly converted to mass density and elemental composition using their respective functions that have been calibrated specifically for the relevant x-ray CT system. We propose an alternative approach that is a conversion in two steps: the first from CT number to density and the second from density to composition. Based on the latest compilation of standard tissues for reference adult male and female phantoms, we sorted the standard tissues into groups by mass density and defined the representative tissues by averaging the material properties per group. With these representative tissues, we formulated polyline relations between mass density and each of the following; electron density, stopping-power ratio and elemental densities. We also revised a procedure of stoichiometric calibration for CT-number conversion and demonstrated the two-step conversion method for a theoretically emulated CT system with hypothetical 80 keV photons. For the standard tissues, high correlation was generally observed between mass density and the other densities excluding those of C and O for the light spongiosa tissues between 1.0 g cm-3 and 1.1 g cm-3 occupying 1% of the human body mass. The polylines fitted to the dominant tissues were generally consistent with similar formulations in the literature. The two-step conversion procedure was demonstrated to be practical and will potentially facilitate Monte Carlo simulation for treatment planning and for retrospective analysis of treatment plans with little impact on the management of planning CT systems.

  15. Regional cerebral blood flow measurement by N-isopropyl-p-(/sup 123/I) iodoamphetamine. A comparison with X-ray CT findings in hemiplegic patients

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Y.; Kuriyama, M.; Sudo, M.; Maeda, N.; Ishii, Y.; Konishi, K.; Nakamura, K.

    1987-05-01

    Eight patients with hemiplegia in chronic stages were studied with N-isopropyl-p-(/sup 123/I) iodoamphetamine (IMP) and single-photon emission computed tomography (SPECT) comparing with X-ray CT findings. In three patients, focal decreases of IMP were observed and these areas were larger than the abnormal areas found by X-ray CT. In the other five patients, hemispherical low perfusion of IMP was observed by SPECT, but X-ray CT showed severe atrophy with normal density. In two patients, cerebral angiography showed no abnormalities in the arterial phase. Regional cerebral blood flow measurement using IMP would be of great value in evaluating abnormal cerebral functions in the chronic state of acute infantile hemiplegia and cerebral palsy.

  16. Assessment of Brain absorbed X-ray dose during CT- Scan using ImPACT software in Tehran Univeristy hospitals

    Directory of Open Access Journals (Sweden)

    Khalilpour M

    2009-07-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 st1":*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: CT scan was first introduced into clinical practice in 1972, and since then has grown into one of the predominant diagnostic procedures. In 1998, the UK National Radiological Protection Board reported that 20% of the national collective dose from medical X-ray examinations derived from CT-scans, although it represented only 2% of all X- ray examinations the aim of this study was to determine the X-ray dosage received by patients in brain CT scan."n"n Methods: In this work, we have estimated patient dose arising from CT examination of brain in five hospitals in Tehran. Organ and effective doses were estimated for 150 patients who underwent CT examination of brain. "ImPACT" version 0.99v was used to estimate organ and effective dose. Brain examinations were performed with fixed Kvp, mAs and T (slice thickness for each scanner. "n"n Results: Patients, who were scanned by CT of emam Khomeini center (Toshiba Xvision /EX Scanner, received maximum organ dose (brain and minimum organ dose was delivered to patients who were scanned by CT of amir alam center (Toshiba Xvision /EX Scanner. Maximum effective dose was 1.7 mSv acquired in this study for emam Khomeini haspital, smaller than

  17. A neural network-based method for spectral distortion correction in photon counting x-ray CT

    Science.gov (United States)

    Touch, Mengheng; Clark, Darin P.; Barber, William; Badea, Cristian T.

    2016-08-01

    Spectral CT using a photon counting x-ray detector (PCXD) shows great potential for measuring material composition based on energy dependent x-ray attenuation. Spectral CT is especially suited for imaging with K-edge contrast agents to address the otherwise limited contrast in soft tissues. We have developed a micro-CT system based on a PCXD. This system enables both 4 energy bins acquisition, as well as full-spectrum mode in which the energy thresholds of the PCXD are swept to sample the full energy spectrum for each detector element and projection angle. Measurements provided by the PCXD, however, are distorted due to undesirable physical effects in the detector and can be very noisy due to photon starvation in narrow energy bins. To address spectral distortions, we propose and demonstrate a novel artificial neural network (ANN)-based spectral distortion correction mechanism, which learns to undo the distortion in spectral CT, resulting in improved material decomposition accuracy. To address noise, post-reconstruction denoising based on bilateral filtration, which jointly enforces intensity gradient sparsity between spectral samples, is used to further improve the robustness of ANN training and material decomposition accuracy. Our ANN-based distortion correction method is calibrated using 3D-printed phantoms and a model of our spectral CT system. To enable realistic simulations and validation of our method, we first modeled the spectral distortions using experimental data acquired from 109Cd and 133Ba radioactive sources measured with our PCXD. Next, we trained an ANN to learn the relationship between the distorted spectral CT projections and the ideal, distortion-free projections in a calibration step. This required knowledge of the ground truth, distortion-free spectral CT projections, which were obtained by simulating a spectral CT scan of the digital version of a 3D-printed phantom. Once the training was completed, the trained ANN was used to perform

  18. Simulating stress-dependent fluid flow in a fractured core sample using real-time X-ray CT data

    Science.gov (United States)

    Kling, Tobias; Huo, Da; Schwarz, Jens-Oliver; Enzmann, Frieder; Benson, Sally; Blum, Philipp

    2016-07-01

    Various geoscientific applications require a fast prediction of fracture permeability for an optimal workflow. Hence, the objective of the current study is to introduce and validate a practical method to characterize and approximate single flow in fractures under different stress conditions by using a core-flooding apparatus, in situ X-ray computed tomography (CT) scans and a finite-volume method solving the Navier-Stokes-Brinkman equations. The permeability of the fractured sandstone sample was measured stepwise during a loading-unloading cycle (0.7 to 22.1 MPa and back) to validate the numerical results. Simultaneously, the pressurized core sample was imaged with a medical X-ray CT scanner with a voxel dimension of 0.5 × 0.5 × 1.0 mm3. Fracture geometries were obtained by CT images based on a modification of the simplified missing attenuation (MSMA) approach. Simulation results revealed both qualitative plausibility and a quantitative approximation of the experimentally derived permeabilities. The qualitative results indicate flow channeling along several preferential flow paths with less pronounced tortuosity. Significant changes in permeability can be assigned to temporal and permanent changes within the fracture due to applied stresses. The deviations of the quantitative results appear to be mainly caused by both local underestimation of hydraulic properties due to compositional matrix heterogeneities and the low CT resolution affecting the accurate capturing of sub-grid-scale features. Both affect the proper reproduction of the actual connectivity and therefore also the depiction of the expected permeability hysteresis. Furthermore, the threshold value CTmat (1862.6 HU) depicting the matrix material represents the most sensitive input parameter of the simulations. Small variations of CTmat can cause enormous changes in simulated permeability by up to a factor of 2.6 ± 0.1 and, thus, have to be defined with caution. Nevertheless, comparison with further CT

  19. Predicting Soil Physical Parameters and Copper Transport in a Polluted Field From X Ray CT-Images

    DEFF Research Database (Denmark)

    Paradelo Pérez, Marcos; Naveed, Muhammad; Møldrup, Per

    2013-01-01

    The development of 3D imaging techniques provides non-destructive tools to reveal the soil structure. X-ray computed tomography (CT) analysis has succeeded in predicting pore network properties such as macropore size distribution, tortuosity, and hydraulic properties. Since contaminant transport...... in soils is strongly controlled by the soil structure, the capabilities of these visualization techniques could be used to predict the risk of pollutants leaching. This work was carried out using soils from a field site (Hygum) in Jutland, Denmark, a historical copper (Cu) polluted field cultivated for 80...... to the volume of each soil column. Leaching experiments were performed to analyze tritium transport, colloid leaching and dissolved organic carbon and Cu losses associated with particles or dissolved organic matter (DOM). Air permeability and saturated hydraulic conductivity were measured before and after...

  20. Standard practice for digital imaging and communication in nondestructive evaluation (DICONDE) for X-ray computed tomography (CT) test methods

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice facilitates the interoperability of X-ray computed tomography (CT) imaging equipment by specifying image data transfer and archival storage methods in commonly accepted terms. This document is intended to be used in conjunction with Practice E2339 on Digital Imaging and Communication in Nondestructive Evaluation (DICONDE). Practice E2339 defines an industrial adaptation of the NEMA Standards Publication titled Digital Imaging and Communications in Medicine (DICOM, see http://medical.nema.org), an international standard for image data acquisition, review, storage and archival storage. The goal of Practice E2339, commonly referred to as DICONDE, is to provide a standard that facilitates the display and analysis of NDE test results on any system conforming to the DICONDE standard. Toward that end, Practice E2339 provides a data dictionary and a set of information modules that are applicable to all NDE modalities. This practice supplements Practice E2339 by providing information object definitio...

  1. Explaining Air and Water Transport in Undisturbed Soils By X-Ray CT Derived Macroporosity and CT- Number-Derived Matrix Density

    DEFF Research Database (Denmark)

    Paradelo Pérez, Marcos; Katuwal, Sheela; Møldrup, Per

    The characterization of soil pore space geometry is important to predict the fluxes of air, water and solutes through soil and understand soil hydrogeochemical functions. X-ray computed tomography (CT) -derived parameters were evaluated as predictors of water, air and solute transport through soil....... Forty five soil columns (20-cm × 20-cm) were collected at an agricultural field in Estrup, Denmark. The soil columns were scanned in a medical CT-scanner. Subsequent to this, non-reactive tracer leaching experiments were performed in the laboratory together with measurements of air permeability (Ka...... is considered a robust indicator of preferential flow. Meanwhile, CT-derived limiting macro-porosity was the best predictor for Ka and log10Ksat. A best subsets regression analysis was performed combining macroporosity, limiting macroporosity and CTmatrix. The predictions of water and air flow improved using...

  2. Investigation on the influence of image quality in X-ray CT metrology

    DEFF Research Database (Denmark)

    Müller, Pavel; Hiller, Jochen; Cantatore, Angela;

    This paper presents a method for evaluating measuring errors in a CT system using information from quality of reconstruction images. In particular, spatial resolution and pixel noise are considered in this work. Both factors can be theoretically described using formulas, and can be expressed as a...

  3. Quantification of C2 cervical spine rotatory fixation by X-ray, MRI and CT

    Energy Technology Data Exchange (ETDEWEB)

    Gradl, Georg [Chirurgische Klinik und Poliklinik der Universitaet Rostock, Abteilung Unfall- und Wiederherstellungschirurgie, Rostock (Germany); Maier-Bosse, Tamara; Staebler, Axel [Institut fuer Radiologische Diagnostik der Universitaet Muenchen, Klinikum Grobetahadern, Munich (Germany); Penning, Randolph [Institut fuer Rechtsmedizin der Universitaet Muenchen, Munich (Germany)

    2005-02-01

    Atlanto-axial rotatory displacement is known to be a cause of childhood torticollis and may as well be responsible for chronic neck pain after rear-end automobile collisions. The objective was to determine whether quantification of C2 malrotation is possible by plain radiographs in comparison to CT as the golden standard. MR imaging was evaluated as to whether it was of equal value in the detection of bony landmarks. C2 vertebra of five human cadaveric cervical spine specimens, ligamentously intact, were rotated using a Steinmann pin in steps of 5 up to 15 right and 15 left. Plain radiographs, CT and MRI images were taken in each rotational step. Data were analyzed for quantification of C2 rotation by three independent examiners. A rotation of 5 led to a spinous process deviation (SPD) from the midline of 3 mm as measured on an a.p. plain radiograph. A coefficient of rotation was calculated (1.62 mm{sup -1}). Data analyzed by three examiners revealed a small coefficient of variation (0.03). MRI and CT measurements showed comparable results for the quantification of rotation; however, in both techniques the 15 rotation was underestimated. Quantification of upper cervical spine malrotation was possible on plain radiographs using the SPD and a rotation coefficient. MRI and CT were equally successful in the assessment of C2 malrotation. (orig.)

  4. Multimodality correlations of patellar height measurement on X-ray, CT, and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Pearlene P.; Chalian, Majid; Carrino, John A.; Eng, John; Chhabra, Avneesh [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States)

    2012-10-15

    To investigate whether the universally accepted range of normal patellar height ratios derived from radiography for the Insall-Salvati (IS) and Blackburne-Peel (BP) methods could be similarly applied to both CT and MRI. Institutional review board approval was obtained with waiver of informed consent for this HIPPA-compliant study. A total of 45 knees in 42 patients (15 men, 27 women; age range 11 to 75 years, mean age 39 {+-} 20 years) who underwent tri-modality (radiograph, CT, and MRI) examinations were selected. All patients had knee imaging obtained for a variety of reasons and measurements were performed by two independent readers who were blinded to each other's measurements or the respective measurements derived from each of the methods. Paired t test was used to compare the mean values among the modalities. Inter-observer and inter-method agreements were assessed using intra-class correlation coefficients. Statistically significant, but small quantitative differences are noted between tri-modality patellar height ratios. For comparable results, the small addition of 0.13 and 0.10 are needed for the Insall-Salvati measurements on MRI and CT respectively, compared with radiographs. For the Blackburne-Peel ratio, an additional adjustment of 0.09 is needed between radiographs and MRI, but not between radiographs and CT. These adjustments are independent of gender. The interobserver reproducibility was excellent (ICC {>=} 0.94) for both the Insall-Salvati and Blackburne-Peel methods for all modalities. The results indicate that cut-off values for patella alta and baja derived from radiographs should not be directly transposed to CT and MRI; however, the adjustments are relatively minor. These measurements show excellent reproducibility for all modalities currently used for patellar height measurements. (orig.)

  5. Arterial wall perfusion measured with photon counting spectral x-ray CT

    Science.gov (United States)

    Jorgensen, Steven M.; Korinek, Mark J.; Vercnocke, Andrew J.; Anderson, Jill L.; Halaweish, Ahmed; Leng, Shuai; McCollough, Cynthia H.; Ritman, Erik L.

    2016-10-01

    Early atherosclerosis changes perfusion of the arterial wall due to localized proliferation of the vasa vasorum. When contrast agent passes through the artery, some enters the vasa vasorum and increases radiopacity of the arterial wall. Technical challenges to detecting changes in vasa vasorum density include the thin arterial wall, partial volume averaging at the arterial lumen/wall interface and calcification within the wall. We used a photon-counting spectral CT scanner to study carotid arteries of anesthetized pigs and micro-CT of these arteries to quantify vasa vasorum density. The left carotid artery wall was injected with autologous blood to stimulate vasa vasorum angiogenesis. The scans were performed at 25-120 keV; the tube-current-time product was 550 mAs. A 60 mL bolus of iodine contrast agent was injected into the femoral vein at 5mL/s. Two seconds post injection, an axial scan was acquired at every 3 s over 60 s (i.e., 20 time points). Each time point acquired 28 contiguous transaxial slices with reconstructed voxels 0.16 x 0.16 x 1 mm3. Regions-of-interest in the outer 2/3 of the arterial wall and in the middle 2/3 of the lumen were drawn and their enhancements plotted versus time. Lumenal CT values peaked several seconds after injection and then returned towards baseline. Arterial wall CT values peaked concurrent to the lumen. The peak arterial wall enhancement in the left carotid arterial wall correlated with increased vasa vasorum density observed in micro-CT images of the isolated arteries.

  6. Automated segmentation of middle hepatic vein in non-contrast x-ray CT images based on an atlas-driven approach

    Science.gov (United States)

    Kitagawa, Teruhiko; Zhou, Xiangrong; Hara, Takeshi; Fujita, Hiroshi; Yokoyama, Ryujiro; Kondo, Hiroshi; Kanematsu, Masayuki; Hoshi, Hiroaki

    2008-03-01

    In order to support the diagnosis of hepatic diseases, understanding the anatomical structures of hepatic lobes and hepatic vessels is necessary. Although viewing and understanding the hepatic vessels in contrast media-enhanced CT images is easy, the observation of the hepatic vessels in non-contrast X-ray CT images that are widely used for the screening purpose is difficult. We are developing a computer-aided diagnosis (CAD) system to support the liver diagnosis based on non-contrast X-ray CT images. This paper proposes a new approach to segment the middle hepatic vein (MHV), a key structure (landmark) for separating the liver region into left and right lobes. Extraction and classification of hepatic vessels are difficult in non-contrast X-ray CT images because the contrast between hepatic vessels and other liver tissues is low. Our approach uses an atlas-driven method by the following three stages. (1) Construction of liver atlases of left and right hepatic lobes using a learning datasets. (2) Fully-automated enhancement and extraction of hepatic vessels in liver regions. (3) Extraction of MHV based on the results of (1) and (2). The proposed approach was applied to 22 normal liver cases of non-contrast X-ray CT images. The preliminary results show that the proposed approach achieves the success in 14 cases for MHV extraction.

  7. First-order convex feasibility algorithms for x-ray CT

    DEFF Research Database (Denmark)

    Sidky, Emil Y.; Jørgensen, Jakob Heide; Pan, Xiaochuan

    2013-01-01

    Purpose: Iterative image reconstruction (IIR) algorithms in computed tomography (CT) are based on algorithms for solving a particular optimization problem. Design of the IIR algorithm, therefore, is aided by knowledge of the solution to the optimization problem on which it is based. Often times......, however, it is impractical to achieve accurate solution to the optimization of interest, which complicates design of IIR algorithms. This issue is particularly acute for CT with a limited angular-range scan, which leads to poorly conditioned system matrices and difficult to solve optimization problems....... In this paper, we develop IIR algorithms which solve a certain type of optimization called convex feasibility. The convex feasibility approach can provide alternatives to unconstrained optimization approaches and at the same time allow for rapidly convergent algorithms for their solution—thereby facilitating...

  8. X-ray phase-contrast CT imaging of the acupoints based on synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chenglin, Liu, E-mail: lclyctc@163.com [Physics Department of Yancheng Teachers’ College, Yancheng 224051 (China); Xiaohua, Wang; Hua, Xu [Physics Department of Yancheng Teachers’ College, Yancheng 224051 (China); Fang, Liu; Ruishan, Dang [Anatomy Department of Second Military Medical University, Shanghai 200433 (China); Dongming, Zhang; Xinyi, Zhang [Synchrotron Radiation Research Center of Fudan University, Shanghai 200433 (China); Honglan, Xie; Tiqiao, Xiao [Shanghai Synchrotron Radiation Facility of Shanghai Institute of Applied Physics, CAS, Shanghai 201800 (China)

    2014-10-15

    In this paper, the morphology of the acupuncture point (abbreviated as acupoint hereafter) or tissue where there were no acupoints in the fractional rabbit hind limb was studied by in-line phase contrast CT imaging (PCI-CT) methods based on synchrotron radiation. The density of micro-vessels was calculated for tissues with acupoints or without acupoints. Differences between acupoints area and non-acupoint areas determined by the density of the micro-vessels propose a strong evidence of the existence of acupoints. Our results showed that there were two significantly higher densities of the micro-vessels, where two acupoints were located, respectively. In addition, there were large numbers of involutedly microvascular structure in the acupoint areas. Nevertheless, in non-acupoints area, the microvascular structure was relatively simple and flat.

  9. Automated segmentation of murine lung tumors in x-ray micro-CT images

    Science.gov (United States)

    Swee, Joshua K. Y.; Sheridan, Clare; de Bruin, Elza; Downward, Julian; Lassailly, Francois; Pizarro, Luis

    2014-03-01

    Recent years have seen micro-CT emerge as a means of providing imaging analysis in pre-clinical study, with in-vivo micro-CT having been shown to be particularly applicable to the examination of murine lung tumors. Despite this, existing studies have involved substantial human intervention during the image analysis process, with the use of fully-automated aids found to be almost non-existent. We present a new approach to automate the segmentation of murine lung tumors designed specifically for in-vivo micro-CT-based pre-clinical lung cancer studies that addresses the specific requirements of such study, as well as the limitations human-centric segmentation approaches experience when applied to such micro-CT data. Our approach consists of three distinct stages, and begins by utilizing edge enhancing and vessel enhancing non-linear anisotropic diffusion filters to extract anatomy masks (lung/vessel structure) in a pre-processing stage. Initial candidate detection is then performed through ROI reduction utilizing obtained masks and a two-step automated segmentation approach that aims to extract all disconnected objects within the ROI, and consists of Otsu thresholding, mathematical morphology and marker-driven watershed. False positive reduction is finally performed on initial candidates through random-forest-driven classification using the shape, intensity, and spatial features of candidates. We provide validation of our approach using data from an associated lung cancer study, showing favorable results both in terms of detection (sensitivity=86%, specificity=89%) and structural recovery (Dice Similarity=0.88) when compared against manual specialist annotation.

  10. The development of an x-ray computerized tomography (CT) experimental system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, G.N.; Kijek, M.M.; Millar, J.J. [Royal Melbourne Inst. of Tech., VIC (Australia)

    1993-12-31

    This paper describes a prototype experimental CT system that has been recently developed at Applied Physics, RMIT/ Physics, La Trobe UCNV. The system incorporates the scanning mode of the first generation CAT-scanner and is designed to perform the scanning of small objects. A microcomputer is used to control the scanning motions and data collection. The performance of the system was examined by scanning a ball-point pen. 8 refs., 4 figs.

  11. Estimation of liver iron concentration by dual energy CT images: influence of X-ray energy on sensitivity.

    Science.gov (United States)

    Malvarosa, I; Massaroni, C; Liguori, C; Paul, J; Beomonte Zobel, B; Saccomandi, P; Vogl, T J; Silvestri, S; Schena, E

    2014-01-01

    In hemochromatosis an abnormal accumulation of iron is present in parenchymal organs and especially in liver. Among the several techniques employed to diagnose the iron overload, magnetic resonance imaging (MRI) and Computed Tomography (CT) are the most promising non-invasive ones. MRI is largely used but shows limitation including an overestimation of iron and inability to quantify iron at very high concentrations. Therefore, some research groups are focusing on the estimation of iron concentration by CT images. Single X-ray CTs are not able to accurately perform this task in case of the presence of confounding factors (e.g., fat). A potential solution to overcome this concern is the employment of Dual-Energy CT (DECT). The aim of this work is to investigate influence of the kVp and mAs on CT number sensitivity to iron concentration. A phantom with test tubes filled with homogenized porcine liver at different iron concentrations, has been scanned with DECT at different mAs. The images have been analyzed using an ad-hoc developed algorithm which allows minimizing the influence of air bubbles present in the homogenized. Data show that the sensitivity is strongly influenced by kVp (its value almost halves from 80 kVp to 140 kVp; e.g. 0.41 g·μmol(-1) and 0.19 g·μmol(-1) at 80 kVp/120 mAs and 140 kVp/60 mAs respectively), on the other hand the influence of mAs value is negligible.

  12. Large area CMOS active pixel sensor x-ray imager for digital breast tomosynthesis: Analysis, modeling, and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chumin; Kanicki, Jerzy, E-mail: kanicki@eecs.umich.edu [Solid-State Electronics Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Konstantinidis, Anastasios C. [Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom and Diagnostic Radiology and Radiation Protection, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester M20 4BX (United Kingdom); Patel, Tushita [Department of Physics, University of Virginia, Charlottesville, Virginia 22908 (United States)

    2015-11-15

    Purpose: Large area x-ray imagers based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been proposed for various medical imaging applications including digital breast tomosynthesis (DBT). The low electronic noise (50–300 e{sup −}) of CMOS APS x-ray imagers provides a possible route to shrink the pixel pitch to smaller than 75 μm for microcalcification detection and possible reduction of the DBT mean glandular dose (MGD). Methods: In this study, imaging performance of a large area (29 × 23 cm{sup 2}) CMOS APS x-ray imager [Dexela 2923 MAM (PerkinElmer, London)] with a pixel pitch of 75 μm was characterized and modeled. The authors developed a cascaded system model for CMOS APS x-ray imagers using both a broadband x-ray radiation and monochromatic synchrotron radiation. The experimental data including modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE) were theoretically described using the proposed cascaded system model with satisfactory consistency to experimental results. Both high full well and low full well (LFW) modes of the Dexela 2923 MAM CMOS APS x-ray imager were characterized and modeled. The cascaded system analysis results were further used to extract the contrast-to-noise ratio (CNR) for microcalcifications with sizes of 165–400 μm at various MGDs. The impact of electronic noise on CNR was also evaluated. Results: The LFW mode shows better DQE at low air kerma (K{sub a} < 10 μGy) and should be used for DBT. At current DBT applications, air kerma (K{sub a} ∼ 10 μGy, broadband radiation of 28 kVp), DQE of more than 0.7 and ∼0.3 was achieved using the LFW mode at spatial frequency of 0.5 line pairs per millimeter (lp/mm) and Nyquist frequency ∼6.7 lp/mm, respectively. It is shown that microcalcifications of 165–400 μm in size can be resolved using a MGD range of 0.3–1 mGy, respectively. In comparison to a General Electric GEN2 prototype DBT system (at

  13. Model-Based Iterative Reconstruction for Dual-Energy X-Ray CT Using a Joint Quadratic Likelihood Model.

    Science.gov (United States)

    Zhang, Ruoqiao; Thibault, Jean-Baptiste; Bouman, Charles A; Sauer, Ken D; Hsieh, Jiang

    2014-01-01

    Dual-energy X-ray CT (DECT) has the potential to improve contrast and reduce artifacts as compared to traditional CT. Moreover, by applying model-based iterative reconstruction (MBIR) to dual-energy data, one might also expect to reduce noise and improve resolution. However, the direct implementation of dual-energy MBIR requires the use of a nonlinear forward model, which increases both complexity and computation. Alternatively, simplified forward models have been used which treat the material-decomposed channels separately, but these approaches do not fully account for the statistical dependencies in the channels. In this paper, we present a method for joint dual-energy MBIR (JDE-MBIR), which simplifies the forward model while still accounting for the complete statistical dependency in the material-decomposed sinogram components. The JDE-MBIR approach works by using a quadratic approximation to the polychromatic log-likelihood and a simple but exact nonnegativity constraint in the image domain. We demonstrate that our method is particularly effective when the DECT system uses fast kVp switching, since in this case the model accounts for the inaccuracy of interpolated sinogram entries. Both phantom and clinical results show that the proposed model produces images that compare favorably in quality to previous decomposition-based methods, including FBP and other statistical iterative approaches.

  14. Quantitative 3D shape description of dust particles from treated seeds by means of X-ray micro-CT.

    Science.gov (United States)

    Devarrewaere, Wouter; Foqué, Dieter; Heimbach, Udo; Cantre, Dennis; Nicolai, Bart; Nuyttens, David; Verboven, Pieter

    2015-06-16

    Crop seeds are often treated with pesticides before planting. Pesticide-laden dust particles can be abraded from the seed coating during planting and expelled into the environment, damaging nontarget organisms. Drift of these dust particles depends on their size, shape and density. In this work, we used X-ray micro-CT to examine the size, shape (sphericity) and porosity of dust particles from treated seeds of various crops. The dust properties quantified in this work were very variable in different crops. This variability may be a result of seed morphology, seed batch, treatment composition, treatment technology, seed cleaning or an interaction of these factors. The intraparticle porosity of seed treatment dust particles varied from 0.02 to 0.51 according to the crop and generally increased with particle size. Calculated settling velocities demonstrated that accounting for particle shape and porosity is important in drift studies. For example, the settling velocity of dust particles with an equivalent diameter of 200 μm may vary between 0.1 and 1.2 m s(-1), depending on their shape and density. Our analysis shows that in a wind velocity of 5 m s(-1), such particles ejected at 1 m height may travel between 4 and 50 m from the source before settling. Although micro-CT is a valuable tool to characterize dust particles, the current image processing methodology limits the number of particles that can be analyzed.

  15. A Model of Regularization Parameter Determination in Low-Dose X-Ray CT Reconstruction Based on Dictionary Learning

    Directory of Open Access Journals (Sweden)

    Cheng Zhang

    2015-01-01

    Full Text Available In recent years, X-ray computed tomography (CT is becoming widely used to reveal patient’s anatomical information. However, the side effect of radiation, relating to genetic or cancerous diseases, has caused great public concern. The problem is how to minimize radiation dose significantly while maintaining image quality. As a practical application of compressed sensing theory, one category of methods takes total variation (TV minimization as the sparse constraint, which makes it possible and effective to get a reconstruction image of high quality in the undersampling situation. On the other hand, a preliminary attempt of low-dose CT reconstruction based on dictionary learning seems to be another effective choice. But some critical parameters, such as the regularization parameter, cannot be determined by detecting datasets. In this paper, we propose a reweighted objective function that contributes to a numerical calculation model of the regularization parameter. A number of experiments demonstrate that this strategy performs well with better reconstruction images and saving of a large amount of time.

  16. NOTE: Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy

    Science.gov (United States)

    Baissalov, R.; Sandison, G. A.; Donnelly, B. J.; Saliken, J. C.; McKinnon, J. G.; Muldrew, K.; Rewcastle, J. C.

    2000-05-01

    Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey-scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high-density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent.

  17. Evaluation of Microstructure and Transport Properties of Deteriorated Cementitious Materials from Their X-ray Computed Tomography (CT Images

    Directory of Open Access Journals (Sweden)

    Michael Angelo B. Promentilla

    2016-05-01

    Full Text Available Pore structure, tortuosity and permeability are considered key properties of porous materials such as cement pastes to understand their long-term durability performance. Three-dimensional image analysis techniques were used in this study to quantify pore size, effective porosity, tortuosity, and permeability from the X-ray computed tomography (CT images of deteriorated pastes that were subjected to accelerated leaching test. X-ray microtomography is a noninvasive three-dimensional (3D imaging technique which has been recently gaining attention for material characterization. Coupled with 3D image analysis, the digitized pore can be extracted and computational simulation can be applied to the pore network to measure relevant microstructure and transport properties. At a spatial resolution of 0.50 μm, the effective porosity (ψe was found to be in the range of 0.04 to 0.33. The characteristic pore size (d using a local thickness algorithm was found to be in the range of 3 to 7 μm. The geometric tortuosity (τg based on a 3D random walk simulation in the percolating pore space was found to be in the range of 2.00 to 7.45. The water permeability values (K using US NIST Permeability Stokes Solver range from an order of magnitudes of 10−14 to 10−17 m2. Indications suggest that as effective porosity increases, the geometric tortuosity increases and the permeability decreases. Correlation among these microstructure and transport parameters is also presented in this study.

  18. AIDS complicated with intestinal lymphoma: X-ray radiology,CT scan and pathological findings

    Institute of Scientific and Technical Information of China (English)

    LI Hong-jun; CHENG Jing-liang

    2011-01-01

    Background The non-Hodgkin's lymphoma is the AIDS symbol of tumor, with high incidence and poor prognosis. The purpose of this study was to investigate the radiological demonstrations of AIDS complicated by intestinal lymphoma and its pathological mechanism.Methods CT scan and pathological data of 3 cases of AIDS complicated by intestinal lymphoma were retrospectively analyzed. All the 3 cases received CT diagnostic scanning, including 2 receiving barium enema radiography after lower gastrointestinal tract cleansing, 1 receiving laporotomy to obtain partial thickened intestinal canal for histopathology and 1with autopsy for histopathological analysis.Results Intestinal canal lymphoma occurred at the left intestinal canal in 2 cases and at the right intestinal canal in the other case, with manifestations of unevenly thickened intestinal canal wall, narrowed canal lumen and filling defect. It was pathologically classified as B cell lymphoma.Conclusions AIDS complicated by B cell lymphoma has manifestations of unevenly thickened intestinal canal wall and narrowed canal lumen, which are non-specific. It should be differentiated from other tumors of intestinal canal in its diagnosis.

  19. Ex-situ time-lapse x-ray CT study of 3D micro-structural fatigue damage evolution in uni-directional composites

    DEFF Research Database (Denmark)

    Jespersen, Kristine Munk; Wang, Ying; Zangenberg Hansen, Jens

    2016-01-01

    In this study, the progress of damage under tension-tension fatigue of a uni-directional (UD) glass fibre composite made from a non-crimp fabric is studied using transilluminated white light imaging (TWLI) and X-ray computed tomography (CT). TWLI images are automatically captured throughout...

  20. Systematic errors in digital volume correlation due to the self-heating effect of a laboratory x-ray CT scanner

    Science.gov (United States)

    Wang, B.; Pan, B.; Tao, R.; Lubineau, G.

    2017-04-01

    The use of digital volume correlation (DVC) in combination with a laboratory x-ray computed tomography (CT) for full-field internal 3D deformation measurement of opaque materials has flourished in recent years. During x-ray tomographic imaging, the heat generated by the x-ray tube changes the imaging geometry of x-ray scanner, and further introduces noticeable errors in DVC measurements. In this work, to provide practical guidance high-accuracy DVC measurement, the errors in displacements and strains measured by DVC due to the self-heating for effect of a commercially available x-ray scanner were experimentally investigated. The errors were characterized by performing simple rescan tests with different scan durations. The results indicate that the maximum strain errors associated with the self-heating of the x-ray scanner exceed 400 µε. Possible approaches for minimizing or correcting these displacement and strain errors are discussed. Finally, a series of translation and uniaxial compression tests were performed, in which strain errors were detected and then removed using pre-established artificial dilatational strain-time curve. Experimental results demonstrate the efficacy and accuracy of the proposed strain error correction approach.

  1. Value Comparision of X-ray and CT Diagnosis Chondroblastoma%X线与CT诊断成软骨细胞瘤的价值对照

    Institute of Scientific and Technical Information of China (English)

    苏循玉

    2015-01-01

    Objective To compare and analyze diagnosis value of X-ray and CT for chondroblastoma. Methods 30 cases patients with chondroblastoma in our hospital were choosed, and car ied out X-ray and CT examination respectively. Analyzing the result of two diagnosis. Results X-ray showed lesions on circular or irregular shape of the limitations bone destruction area, while CT display lesions of varying degrees lobulated shape, and lead to half annular calcification, boundary is clear. The two diagnosis were compared, the diagnosis sensitivity of X-ray and CT is al higher, the dif erences had no statistical significance ( >0.05);But the specificity of CT diagnosis is significantly higher than X-ray, the dif erence was statistical y significant ( <0.05). Conclusion X-ray and CT in the diagnosis of into cartilage cel s, they have their own excel ence, but the specificity of the CT diagnosis is bet er than X-ray diagnosis, in the clinical, joint two diagnosis methods can provide more diagnostic information, which play a important role in diagnosis and identify of chondroblastoma.%目的:对比分析X线与CT诊断成软骨细胞瘤的价值。方法选择我院成软骨细胞瘤患者30例,分别行X线与CT检查。分析诊断结果。结果 X线显示病灶为圆形或者不规则形的局限性骨破坏区,而CT显示病灶为不同程度的分叶状,半环形钙化,边界比较清晰。两者诊断结果比较,X线和CT诊断的敏感性都较高,两者比较差异无统计学意义(>0.05);但是CT诊断的特异性显著高于X线诊断的特异性,两者比较差异有统计学意义(<0.05)。结论 X线与CT在诊断成软骨细胞时各有自身的优点,但是CT诊断的特异性优于X线诊断,在临床诊断中联合两种诊断方式能提供更多的诊断信息,对成软骨细胞的诊断和鉴别具有非常大的作用。

  2. Imaging Molecular Signatures of Breast Cancer with X-ray-Activated Nanophosphors

    Science.gov (United States)

    2014-01-01

    the high X-ray noise from the incident irradiation, and the dark counts from thermal noise on the CCD. After connecting the chiller and installing...below a manufacturer-recommended value; this optimal value was chosen to remove low- intensity pixels which corresponded to thermal and read noise on the...distinguish between the different sized objects in the optical dimension, although again, there is a tendency for dilation in the optically-resolved

  3. A constrained, total-variation minimization algorithm for low-intensity X-ray CT

    CERN Document Server

    Sidky, Emil Y; Ullberg, Christer; Pan, Xiaochuan

    2010-01-01

    Purpose: We develop an iterative image-reconstruction algorithm for application to low-intensity computed tomography (CT) projection data, which is based on constrained, total-variation (TV) minimization. The algorithm design focuses on recovering structure on length scales comparable to a detector-bin width. Method: Recovering the resolution on the scale of a detector bin, requires that pixel size be much smaller than the bin width. The resulting image array contains many more pixels than data, and this undersampling is overcome with a combination of Fourier upsampling of each projection and the use of constrained, TV-minimization, as suggested by compressive sensing. The presented pseudo-code for solving constrained, TV-minimization is designed to yield an accurate solution to this optimization problem within 100 iterations. Results: The proposed image-reconstruction algorithm is applied to a low-intensity scan of a rabbit with a thin wire, to test resolution. The proposed algorithm is compared with filtere...

  4. Two and three-dimensional morphometric analysis of trabecular bone using X-ray microtomography (μCT)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alessandro Marcio Hakme da; Silva, Orivaldo Lopes da; Silva Junior, Nelson Ferreira da, E-mail: alhakme@sc.usp.br [Universidade de Sao Paulo (EESC/FMRP/IQSC/USP), Sao Carlos, SP (Brazil); Alves, Jose Marcos [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia. Departamento de Engenharia Eletrica e Computacao

    2014-07-01

    Introduction: trabecular bones have a porous microstructure and can be modeled as linear elastic solids, heterogeneous and anisotropic. In the literature, few investigations have compared the two- dimensional (2D) and three-dimensional (3D) morphometric analyses of cancellous bone. Methods: In this investigation eighteen cylindrical samples of cancellous bone (10 mm of diameter and 20 mm of height) were obtained from six bovine head femurs, with similar values for the weight and age, of the same race and gender. The samples were harvested and freeze at - 20 °C before carrying out the micro CT analysis. The CT-Analyzer software was used to measure in three directions (superior-inferior, lateral-medial and anterior-posterior) parameters such as trabecular thickness, trabecular separation, trabecular number and the eigenvalues of the fabric tensor (M). Results: the Comparison of 2D and 3D analyses for the parameters: 2D (plate model) trabecular thickness, trabecular separation and trabecular number were statistically different (p = 0) showing that measurements are not similar to the 3D ones. However, 2D (rod model) trabecular thickness and 3D trabecular thickness measurements presented no significant difference (p = 0.26). The eigenvalues show that the bovine trabecular microstructure has a tendency to transversally isotropic symmetry. Discussion: The method proved to be quite interesting for the characterization of the bone structure through 3D measurements of trabecular bone morphometric parameters in the three possible directions of loading. The results show that x-ray microtomography (μCT) is a technique of great potential for characterization and generating bone quality parameters for the diagnosis of bone metabolism diseases. (author)

  5. Image performance of a new amorphous selenium flat panel x-ray detector designed for digital breast tomosynthesis

    Science.gov (United States)

    Cheung, L. K.; Jing, Z.; Bogdanovich, S.; Golden, K.; Robinson, S.; Beliaevskaia, E.; Parikh, S.

    2005-04-01

    The purpose of this work is to report the performance of an amorphous selenium (a-Se) based flat-panel x-ray imager under development for application in digital breast tomosynthesis. This detector is designed to perform both in the conventional Full Field Digital Mammography (FFDM) mode and the tomosynthesis mode. The large area 24 x 29 cm detector achieves rapid image acquisition rates of up to 4 frames per second with minimal trapped charge induced effects such as ghost or lag images of previously acquired objects. In this work, a new a-Se/TFT detector layer structure is evaluated. The design uses a top conductive layer in direct contact with the a-Se x-ray detection layer. The simple structure has few layers and minimal hole and electron trapping effects. Prototype detectors were built to investigate the basic image performance of this new a-Se/TFT detector. Image signal generation, image ghosting, image lag, and detector DQE were studied. For digital mammography applications, the residual image ghosting was less than 1% at 30 seconds elapsed time. DQE, measured at a field of 5.15 V/um, showed significantly higher values over previously reported data, especially at low exposure levels. For digital breast tomosynthesis, the image lag at dynamic readout rate was < 0.6 % at 0.5-second elapsed time. A prototype tomosynthesis system is being developed utilizing this new a-Se/TFT detector.

  6. X-ray microCT imaging technique reveals corm microstructures of an arctic-boreal cotton-sedge, Eriophorum vaginatum.

    Science.gov (United States)

    Bogart, Sarah J; Spiers, Graeme; Cholewa, Ewa

    2010-09-01

    X-ray computed tomography (CT), a non-destructive imaging technique, has recently been effectively applied to botanical research. In this study an X-ray microCT technique was developed to allow for anatomical study of the overwintering corms of Eriophorum vaginatum, an ecologically important sedge species in arctic tussock-tundra and boreal peatlands. Using a GE Medical MS8X-130 X-ray microCT scanner, optimal imaging parameters included scanning isolated corms at 80 k Vp and 100 microA with a 3500 ms exposure time and an isotropic voxel size of 10 microm. A Gaussian blur image filter with a blur radius (sigma) of two pixels was applied to the optimal dataset to improve visual detection and contrast of tissues while removing 99.2% of image noise. Using the developed X-ray microCT technique several undocumented anatomical characteristics of the corm were identified including the vascular connection between a parent corm and branching cormel and the 3D shape of sclereid clusters. The 3D structure of sclereid clusters was determined whereby the perimeter of their lance shape is greatly reinforced by sclereids with thicker secondary cell walls as compared to those of the interior of the cluster. The structure of sclereid clusters and their association with leaf traces suggests they may be stabilizing the corm-leaf connection to protect vascular tissues from physical damage. The proposed X-ray microCT technique is an excellent tool for determination of the 3D structure of E. vaginatum corms and may be used to detect alterations in tissue structure and chemistry in response to environmental change in this and other Cyperaceous species.

  7. X-ray and ultrasound semiotics of mucinous carcinoma of the breast

    Directory of Open Access Journals (Sweden)

    K. A. Lesko

    2013-01-01

    Full Text Available The article describes the main epidemiological, clinical and morphological diagnostic features of one of the rare breast cancer form – mucinous carcinoma of the breast. Current scientific data are followed by the results of own research the 9-year period of research.Authors draw attention to the very complex radiology peculiarities of the mucinous carcinoma of the breast.

  8. Prospective-gated cardiac micro-CT imaging of free-breathing mice using carbon nanotube field emission x-ray

    Energy Technology Data Exchange (ETDEWEB)

    Cao Guohua; Burk, Laurel M.; Lee, Yueh Z.; Calderon-Colon, Xiomara; Sultana, Shabana; Lu Jianping; Zhou, Otto [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 and Department of Radiology, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States) and Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States) and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

    2010-10-15

    Purpose: Carbon nanotube (CNT) based field emission x-ray source technology has recently been investigated for diagnostic imaging applications because of its attractive characteristics including electronic programmability, fast switching, distributed source, and multiplexing. The purpose of this article is to demonstrate the potential of this technology for high-resolution prospective-gated cardiac micro-CT imaging. Methods: A dynamic cone-beam micro-CT scanner was constructed using a rotating gantry, a stationary mouse bed, a flat-panel detector, and a sealed CNT based microfocus x-ray source. The compact single-beam CNT x-ray source was operated at 50 KVp and 2 mA anode current with 100 {mu}mx100 {mu}m effective focal spot size. Using an intravenously administered iodinated blood-pool contrast agent, prospective cardiac and respiratory-gated micro-CT images of beating mouse hearts were obtained from ten anesthetized free-breathing mice in their natural position. Four-dimensional cardiac images were also obtained by gating the image acquisition to different phases in the cardiac cycle. Results: High-resolution CT images of beating mouse hearts were obtained at 15 ms temporal resolution and 6.2 lp/mm spatial resolution at 10% of system MTF. The images were reconstructed at 76 {mu}m isotropic voxel size. The data acquisition time for two cardiac phases was 44{+-}9 min. The CT values observed within the ventricles and the ventricle wall were 455{+-}49 and 120{+-}48 HU, respectively. The entrance dose for the acquisition of a single phase of the cardiac cycle was 0.10 Gy. Conclusions: A high-resolution dynamic micro-CT scanner was developed from a compact CNT microfocus x-ray source and its feasibility for prospective-gated cardiac micro-CT imaging of free-breathing mice under their natural position was demonstrated.

  9. Lung cancer screening with thoracic X-ray and CT. Current situation; Lungenkarzinomscreening mit Roentgenthorax oder CT. Aktuelle Datenlage

    Energy Technology Data Exchange (ETDEWEB)

    Stackelberg, O. von; Kauczor, H.U. [Universitaetsklinikum Heidelberg, Diagnostische und Interventionelle Radiologe, Heidelberg (Germany); Translationales Lungen Forschungszentrum Heidelberg (TLRC), Mitglied des Deutschen Zentrums fuer Lungenforschung (DZL), Heidelberg (Germany)

    2016-09-15

    Attempts at the early detection of lung cancer using imaging methods began as far back as the 1950s. Several studies attempted to demonstrate a reduction of lung cancer mortality by chest radiography screening but all were unsuccessful. Even the first small screening studies using computed tomography (CT) could not demonstrate a reduction in lung cancer-specific mortality until in 2011 the results of the largest randomized controlled low-dose CT screening study in the USA (NLST) were published. The NLST results could show a significant 20 % reduction of lung cancer mortality in elderly and heavy smokers using CT. Confirmation of the NLST results are urgently needed so that the data of the largest European study (NELSON) are eagerly awaited. Pooled with the data from several smaller European studies these results will provide important information and evidence for the establishment of future CT screening programs in Europe. Randomized controlled trials are the basis of evidence-based medicine; therefore, the positive results of the methodologically very good NLST study cannot be ignored, even if it is the only such study completed so far with highly convincing conclusions. The NLST results clearly demonstrate that positive effects for the health of the population can only be expected if the processes are clearly defined and the quality is assured. (orig.) [German] Bestrebungen zur Frueherkennung von Lungenkrebs mit bildgebenden Methoden gibt es schon lange. Alle Studien, die eine Reduktion der Lungenkrebsmortalitaet mittels Roentgenthoraxscreening nachzuweisen versuchten, scheiterten. Auch die ersten kleineren Screeningstudien mit der CT konnten keine Reduktion der Lungenkrebssterblichkeit nachweisen, bis 2011 die Ergebnisse der bisher groessten randomisierten kontrollierten Niedrigdosis-CT-Screeningstudie (NLST) aus den USA veroeffentlicht wurden. Diese konnten eine signifikante 20 %ige Reduktion der Lungenkrebssterblichkeit bei Personen, die aelter und starke

  10. Trace elements as tumor biomarkers and prognostic factors in breast cancer: a study through energy dispersive x-ray fluorescence

    Directory of Open Access Journals (Sweden)

    Silva Marina P

    2012-07-01

    Full Text Available Abstract Background The application and better understanding of traditional and new breast tumor biomarkers and prognostic factors are increasing due to the fact that they are able to identify individuals at high risk of breast cancer, who may benefit from preventive interventions. Also, biomarkers can make possible for physicians to design an individualized treatment for each patient. Previous studies showed that trace elements (TEs determined by X-Ray Fluorescence (XRF techniques are found in significantly higher concentrations in neoplastic breast tissues (malignant and benign when compared with normal tissues. The aim of this work was to evaluate the potential of TEs, determined by the use of the Energy Dispersive X-Ray Fluorescence (EDXRF technique, as biomarkers and prognostic factors in breast cancer. Methods By using EDXRF, we determined Ca, Fe, Cu, and Zn trace elements concentrations in 106 samples of normal and breast cancer tissues. Cut-off values for each TE were determined through Receiver Operating Characteristic (ROC analysis from the TEs distributions. These values were used to set the positive or negative expression. This expression was subsequently correlated with clinical prognostic factors through Fisher’s exact test and chi-square test. Kaplan Meier survival curves were also evaluated to assess the effect of the expression of TEs in the overall patient survival. Results Concentrations of TEs are higher in neoplastic tissues (malignant and benign when compared with normal tissues. Results from ROC analysis showed that TEs can be considered a tumor biomarker because, after establishing a cut-off value, it was possible to classify different tissues as normal or neoplastic, as well as different types of cancer. The expression of TEs was found statistically correlated with age and menstrual status. The survival curves estimated by the Kaplan-Meier method showed that patients with positive expression for Cu presented a poor

  11. Imaging Molecular Signatures of Breast Cancer With X-ray Activated Nano-Phosphors

    Science.gov (United States)

    2011-09-01

    shot-noise limited detection" was assumed to be too low to detect. To calculate the molar concentration, we assumed a spherical 10 nm diameter...Kandarakis et al. !a" Minimum weight concentration !in mg/ml" vs dose !Gy". !b" Minimum molar concentration !in M" vs dose !Gy". a b c d FIG. 5. Agar imaging...Contrast agents: X-ray contrast agents and molecular imaging—A contradiction ?,” Handb Exp Pharmacol 185, 167–175 񓟸#. 3R. Weissleder and M. J. Pittet

  12. Lanthanide-based nanocrystals as dual-modal probes for SPECT and X-ray CT imaging.

    Science.gov (United States)

    Wu, Yongquan; Sun, Yun; Zhu, Xingjun; Liu, Qian; Cao, Tianye; Peng, Juanjuan; Yang, Yang; Feng, Wei; Li, Fuyou

    2014-05-01

    Applications of lanthanide-based nanoparticles for bioimaging have attracted increasing attention. Herein, small size PEG-EuOF:(153)Sm nanocrystals (∼5 nm) (PEG = poly(ethylene glycol)bis(carboxymethyl)ether) combined with the radioactive and X-ray absorption properties were synthesized. The distribution of the PEG-EuOF nanocrystals in living animals was studied by ex vivo radioassay, inductively coupled plasma-atomic emission spectrum (ICP-AES) analysis and in vivo SPECT imaging, which indicated that the small size PEG-EuOF:(153)Sm had long blood retention time (blood half-life (t1/2) reach to 4.65 h) and were eliminated significantly through biliary/gastrointestinal pathway in vivo. Meanwhile, benefiting from the high attenuation ability of Eu, the small size PEG-EuOF was successfully applied for lymph node CT imaging, extending the bio-applications of these small nanocrystals. The results of cytotoxicity and in vivo toxicity also showed that the PEG-EuOF nanocrystals have relatively low toxicity, which suggest their safety for in vivo imaging. The studies provide preliminary validation for the use of PEG-EuOF nanocrystals for in vivo bioimaging applications.

  13. A computationally efficient method for automatic registration of orthogonal x-ray images with volumetric CT data

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xin [ADSIP Research Centre, University of Central Lancashire, Preston (United Kingdom); Varley, Martin R [ADSIP Research Centre, University of Central Lancashire, Preston (United Kingdom); Shark, Lik-Kwan [ADSIP Research Centre, University of Central Lancashire, Preston (United Kingdom); Shentall, Glyn S [Rosemere Cancer Centre, Royal Preston Hospital, Preston (United Kingdom); Kirby, Mike C [Satellite Centres, Christie Hospital NHS Foundation Trust, Manchester (United Kingdom)

    2008-02-21

    The paper presents a computationally efficient 3D-2D image registration algorithm for automatic pre-treatment validation in radiotherapy. The novel aspects of the algorithm include (a) a hybrid cost function based on partial digitally reconstructed radiographs (DRRs) generated along projected anatomical contours and a level set term for similarity measurement; and (b) a fast search method based on parabola fitting and sensitivity-based search order. Using CT and orthogonal x-ray images from a skull and a pelvis phantom, the proposed algorithm is compared with the conventional ray-casting full DRR based registration method. Not only is the algorithm shown to be computationally more efficient with registration time being reduced by a factor of 8, but also the algorithm is shown to offer 50% higher capture range allowing the initial patient displacement up to 15 mm (measured by mean target registration error). For the simulated data, high registration accuracy with average errors of 0.53 mm {+-} 0.12 mm for translation and 0.61 deg, {+-} 0.29 deg. for rotation within the capture range has been achieved. For the tested phantom data, the algorithm has also shown to be robust without being affected by artificial markers in the image.

  14. A computationally efficient method for automatic registration of orthogonal x-ray images with volumetric CT data

    Science.gov (United States)

    Chen, Xin; Varley, Martin R.; Shark, Lik-Kwan; Shentall, Glyn S.; Kirby, Mike C.

    2008-02-01

    The paper presents a computationally efficient 3D-2D image registration algorithm for automatic pre-treatment validation in radiotherapy. The novel aspects of the algorithm include (a) a hybrid cost function based on partial digitally reconstructed radiographs (DRRs) generated along projected anatomical contours and a level set term for similarity measurement; and (b) a fast search method based on parabola fitting and sensitivity-based search order. Using CT and orthogonal x-ray images from a skull and a pelvis phantom, the proposed algorithm is compared with the conventional ray-casting full DRR based registration method. Not only is the algorithm shown to be computationally more efficient with registration time being reduced by a factor of 8, but also the algorithm is shown to offer 50% higher capture range allowing the initial patient displacement up to 15 mm (measured by mean target registration error). For the simulated data, high registration accuracy with average errors of 0.53 mm ± 0.12 mm for translation and 0.61° ± 0.29° for rotation within the capture range has been achieved. For the tested phantom data, the algorithm has also shown to be robust without being affected by artificial markers in the image.

  15. In situ local contact angle measurement in a CO2-brine-sand system using microfocused X-ray CT.

    Science.gov (United States)

    Lv, Pengfei; Liu, Yu; Wang, Zhe; Liu, Shuyang; Jiang, Lanlan; Chen, Junlin; Song, Yongchen

    2017-03-22

    The wettability of porous media is of major interest in a broad range of natural and engineering applications. The wettability of a fluid on a solid surface is usually evaluated by the contact angle between them. While in situ local contact angle measurements are complicated by the topology of porous media, which can make it difficult to use traditional methods, recent advances in microfocused X-ray computed tomography (micro-CT) and image processing techniques have made it possible to measure contact angles on the scale of the pore sizes in such media. However, The effects of ionic strength, CO2 phase, and flow pattern (drainage or imbibition) on pore-scale contact angle distribution still not clear and has not been reported in detail in previous study. In this study, we employed a micro-CT scanner for in situ investigation of local contact angles in a CO2-brine-sand system under various conditions. The effects of ionic strength, CO2 phase, and flow pattern on the local contact-angle distribution were examined in detail. The results showed that the local contact angles vary over a wide range as a result of the interaction of surface contaminants, roughness, pore topology and capillarity. The wettability of a porous surface could thus slowly weaken with increasing ionic strength, and the average contact angle could significantly increase when gaseous CO2 (gCO2) turns into supercritical CO2 (scCO2). Contact angle hysteresis also occurred between drainage and imbibition procedures, and the hysteresis was more significant under gCO2 condition.

  16. 强直性脊柱炎的X线平片和CT诊断%X-ray plain radiographs and CT diagnosis of ankylosing spondylitis

    Institute of Scientific and Technical Information of China (English)

    段常青

    2016-01-01

    目的:探讨X线平片和CT检查对强直性脊柱炎的诊断价值。方法:收治强直性脊柱炎患者70例作为研究对象,分别给予X线平片检查和CT检查。结果:CT检查确诊率100.0%,明显高于X线平片检查,差异有统计学意义(P<0.05)。结论:CT检查对强直性脊柱炎的诊断率高,且能发现微小病变,灵敏度高。%Objective:To investigate the diagnosis value of X-ray plain radiographs and CT for ankylosing spondylitis.Methods:70 cases of patients with ankylosing spondylitis were as the research object and were given X-ray plain radiographs and CT.Results:The diagnosis rate of CT was 100%,which was significantly higher than that of X-ray plain radiographs,and the difference was statistically significant(P<0.05).Conclusion:The diagnosis rate of CT examination for ankylosing spondylitis was high.It could detect small lesions and it had high sensitivity.

  17. Quantification of Soil Physical Properties by Using X-Ray Computerized Tomography (CT) and Standard Laboratory (STD) Methods

    Energy Technology Data Exchange (ETDEWEB)

    Maria Ambert Sanchez

    2003-12-12

    The implementation of x-ray computerized tomography (CT) on agricultural soils has been used in this research to quantify soil physical properties to be compared with standard laboratory (STD) methods. The overall research objective was to more accurately quantify soil physical properties for long-term management systems. Two field studies were conducted at Iowa State University's Northeast Research and Demonstration Farm near Nashua, IA using two different soil management strategies. The first field study was conducted in 1999 using continuous corn crop rotation for soil under chisel plow with no-till treatments. The second study was conducted in 2001 and on soybean crop rotation for the same soil but under chisel plow and no-till practices with wheel track and no-wheel track compaction treatments induced by a tractor-manure wagon. In addition, saturated hydraulic (K{sub s}) conductivity and the convection-dispersion (CDE) model were also applied using long-term soil management systems only during 2001. The results obtained for the 1999 field study revealed no significant differences between treatments and laboratory methods, but significant differences were found at deeper depths of the soil column for tillage treatments. The results for standard laboratory procedure versus CT method showed significant differences at deeper depths for the chisel plow treatment and at the second lower depth for no-till treatment for both laboratory methods. The macroporosity distribution experiment showed significant differences at the two lower depths between tillage practices. Bulk density and percent porosity had significant differences at the two lower depths of the soil column. The results obtained for the 2001 field study showed no significant differences between tillage practices and compaction practices for both laboratory methods, but significant differences between tillage practices with wheel track and no-wheel compaction treatments were found along the soil

  18. Contrast-Enhanced Proton Radiography for Patient Set-up by Using X-Ray CT Prior Knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Spadea, Maria Francesca, E-mail: mfspadea@unicz.it [Department of Experimental and Clinical Medicine, Magna Graecia University, Catanzaro (Italy); Fassi, Aurora [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Zaffino, Paolo [Department of Experimental and Clinical Medicine, Magna Graecia University, Catanzaro (Italy); Riboldi, Marco; Baroni, Guido [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit—CNAO Foundation, Pavia (Italy); Depauw, Nicolas [Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts (United States); Centre for Medical Radiation Physics, University of Wollongong, Wollongong (Australia); Seco, Joao [Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts (United States)

    2014-11-01

    Purpose: To obtain a contrasted image of the tumor region during the setup for proton therapy in lung patients, by using proton radiography and x-ray computed tomography (CT) prior knowledge. Methods and Materials: Six lung cancer patients' CT scans were preprocessed by masking out the gross tumor volume (GTV), and digitally reconstructed radiographs along the planned beam's eye view (BEV) were generated, for a total of 27 projections. Proton radiographies (PR) were also computed for the same BEV through Monte Carlo simulations. The digitally reconstructed radiograph was subtracted from the corresponding proton image, resulting in a contrast-enhanced proton radiography (CEPR). Michelson contrast analysis was performed both on PR and CEPR. The tumor region was then automatically segmented on CEPR and compared to the ground truth (GT) provided by physicians in terms of Dice coefficient, accuracy, precision, sensitivity, and specificity. Results: Contrast on CEPR was, on average, 4 times better than on PR. For 10 lateral projections (±45° off of 90° or 270°), although it was not possible to distinguish the tumor region in the PR, CEPR offers excellent GTV visibility. The median ± quartile values of Dice, precision, and accuracy indexes were 0.86 ± 0.03, 0.86 ± 0.06, and 0.88 ± 0.02, respectively, thus confirming the reliability of the method in highlighting tumor boundaries. Sensitivity and specificity analysis demonstrated that there is no systematic over- or underestimation of the tumor region. Identification of the tumor boundaries using CEPR resulted in a more accurate and precise definition of GTV compared to that obtained from pretreatment CT. Conclusions: In most proton centers, the current clinical protocol is to align the patient using kV imaging with bony anatomy as a reference. We demonstrated that CEPR can significantly improve tumor visualization, allowing better patient set-up and permitting image guided proton therapy (IGPT)

  19. Observer-model optimization of X-ray system in photon-counting breast imaging

    Science.gov (United States)

    Cederström, Björn; Fredenberg, Erik; Lundqvist, Mats; Ericson, Tove; Åslund, Magnus

    2011-08-01

    An ideal-observer model is applied to optimize the design of an X-ray tube intended for use in a multi-slit scanning photon-counting mammography system. The design is such that the anode and the heel effect are reversed and the projected focal spot is smallest at the chest wall. Using linear systems theory, detectability and dose efficiency for a 0.1-mm disk are calculated for different focal spot sizes and anode angles. It is shown that the image acquisition time can be reduced by about 25% with spatial resolution and dose efficiency improved near the chest wall and worsened further away. The image quality is significantly more homogeneous than for the conventional anode orientation, both with respect to noise and detectability of a small object. With the tube rotated 90∘, dose efficiency can be improved by 20% for a fixed image acquisition time.

  20. γ-H2AX foci as in vivo effect biomarker in children emphasize the importance to minimize X-ray doses in paediatric CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vandevoorde, C.; Franck, C.; Bacher, K.; Thierens, H. [Ghent University, Department of Basic Medical Sciences, Gent (Belgium); Breysem, L.; Smet, M.H. [University Hospital Louvain, Radiology Department, Leuven (Belgium); Ernst, C. [University Hospital Brussels, Radiology Department, Brussels (Belgium); Backer, A. de [General Hospital Sint-Lucas Ghent, Radiology Department, Ghent (Belgium); Moortele, K. van de [General Hospital Sint-Jan Bruges, Radiology Department, Bruges (Belgium); Smeets, P. [Ghent University Hospital, Radiology Department, Ghent (Belgium)

    2014-10-30

    Investigation of DNA damage induced by CT x-rays in paediatric patients versus patient dose in a multicentre setting. From 51 paediatric patients (median age, 3.8 years) who underwent an abdomen or chest CT examination in one of the five participating radiology departments, blood samples were taken before and shortly after the examination. DNA damage was estimated by scoring γ-H2AX foci in peripheral blood T lymphocytes. Patient-specific organ and tissue doses were calculated with a validated Monte Carlo program. Individual lifetime attributable risks (LAR) for cancer incidence and mortality were estimated according to the BEIR VII risk models. Despite the low CT doses, a median increase of 0.13 γ-H2AX foci/cell was observed. Plotting the induced γ-H2AX foci versus blood dose indicated a low-dose hypersensitivity, supported also by an in vitro dose-response study. Differences in dose levels between radiology centres were reflected in differences in DNA damage. LAR of cancer mortality for the paediatric chest CT and abdomen CT cohort was 0.08 and 0.13 permille respectively. CT x-rays induce DNA damage in paediatric patients even at low doses and the level of DNA damage is reduced by application of more effective CT dose reduction techniques and paediatric protocols. (orig.)

  1. Efficient iterative image reconstruction algorithm for dedicated breast CT

    Science.gov (United States)

    Antropova, Natalia; Sanchez, Adrian; Reiser, Ingrid S.; Sidky, Emil Y.; Boone, John; Pan, Xiaochuan

    2016-03-01

    Dedicated breast computed tomography (bCT) is currently being studied as a potential screening method for breast cancer. The X-ray exposure is set low to achieve an average glandular dose comparable to that of mammography, yielding projection data that contains high levels of noise. Iterative image reconstruction (IIR) algorithms may be well-suited for the system since they potentially reduce the effects of noise in the reconstructed images. However, IIR outcomes can be difficult to control since the algorithm parameters do not directly correspond to the image properties. Also, IIR algorithms are computationally demanding and have optimal parameter settings that depend on the size and shape of the breast and positioning of the patient. In this work, we design an efficient IIR algorithm with meaningful parameter specifications and that can be used on a large, diverse sample of bCT cases. The flexibility and efficiency of this method comes from having the final image produced by a linear combination of two separately reconstructed images - one containing gray level information and the other with enhanced high frequency components. Both of the images result from few iterations of separate IIR algorithms. The proposed algorithm depends on two parameters both of which have a well-defined impact on image quality. The algorithm is applied to numerous bCT cases from a dedicated bCT prototype system developed at University of California, Davis.

  2. Experimental investigation for determination of optimal X-ray beam tube voltages in a newly developed digital breast tomosynthesis system

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hye-Suk, E-mail: radiosugar@yonsei.ac.kr [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju, Gangwon 220-710 (Korea, Republic of); Kim, Ye-Seul, E-mail: radiohesugar@gmail.com [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju, Gangwon 220-710 (Korea, Republic of); Choi, Young-Wook, E-mail: ywchoi@keri.re.kr [Korea Electrotechnology Research Institute (KERI), Ansan, Geongki 426-170 (Korea, Republic of); Choi, JaeGu, E-mail: jgchoi88@paran.com [Korea Electrotechnology Research Institute (KERI), Ansan, Geongki 426-170 (Korea, Republic of); Rhee, Yong-Chun, E-mail: ycrhee@yonsei.ac.kr [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju, Gangwon 220-710 (Korea, Republic of); Kim, Hee-Joung, E-mail: hjk1@yonsei.ac.kr [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju, Gangwon 220-710 (Korea, Republic of)

    2014-11-01

    Our purpose was to investigate optimal tube voltages (kVp) for a newly developed digital breast tomosynthesis (DBT) process and to determine tube current–exposure time products (mA s) for the average glandular dose (AGD), which is similar to that of the two views in conventional mammography (CM). In addition, the optimal acquisition parameters for this system were compared with those of CM. The analysis was based on the contrast-to-noise ratio (CNR) from the simulated micro-calcifications on homogeneous phantoms, and the figure of merit (FOM) was retrieved from the CNR and AGD at X-ray tube voltages ranging from 24 to 40 kVp at intervals of 2 kV. The optimal kVp increased more than 2 kV with increasing glandularity for thicker (≥50 mm) breast phantoms. The optimal kVp for DBT was found to be 4–7 kV higher than that calculated for CM with breast phantoms thicker than 50 mm. This is likely due to the greater effect of noise and dose reduction by kVp increment when using the lower dose per projection in DBT. It is important to determine optimum acquisition conditions for a maximally effective DBT system. The results of our study provide useful information to further improve DBT for high quality imaging.

  3. 工业CT锥束X射线能谱及强度的分布模拟%The Simulation of Cone Beam X-ray Spectrum and Intensity Distribution of X-ray in Industrial CT System

    Institute of Scientific and Technical Information of China (English)

    王玮; 李公平; 潘小东; 王云波

    2014-01-01

    In this paper,the physical process of producing X-rays in the X-ray source used in cone-beam industrial CT system was simulated by Monte Carlo method.The X-ray spectrums with and with no 2 mm iron as filter layers were obtained,respectively.In addition,the angular distribution of the outgoing X-ray flux under different target angles was calculated.Then,the intensity distribution of the X-rays which passed through the obj ect under test was simulated.We obtain the distribution of SPR value and the distribution of X-ray intensity in different positions of the detector plane in different conditions,which are in the same distance between the ray source and the detector and passing through the object of the same diameter.Besides,we also obtain the flux spectrum distribution in the centre of detector and the spatial distribution of the X-ray intensity in some special position.The simulation results in this paper can provide some help and basis for the scatter correction and beam hardening correction in the process of image reconstruction and help to determine the minimum sensitivity of the detector,and provide a reference for the shielding system design.%利用蒙特卡罗方法模拟了锥束工业CT系统中X射线的产生过程,分别得到了未加过滤层和加2 mm铁片作为过滤层情况下的X射线能谱;计算了不同靶面倾角下出射X射线相对强度的角分布。随后模拟了X射线通过被测物体后射线强度的分布,分别得到了射线源与探测器间距离相同时,穿过不同直径被测物体以及经过相同的被测物体,但射线源与探测器间距离不同的两种情况下的系统SPR值的分布以及探测器平面不同位置下射线强度的分布。此外还模拟得到了有无被测物体情况下的探测器中心位置的通量能谱分布及一些特殊位置下射线强度的空间分布。模拟结果可以为CT系统图像重建时的散射校正和射束硬化校正提供数据依据,有助于

  4. Effective incorporation of spatial information in a mutual information based 3D-2D registration of a CT volume to X-ray images.

    Science.gov (United States)

    Zheng, Guoyan

    2008-01-01

    This paper addresses the problem of estimating the 3D rigid pose of a CT volume of an object from its 2D X-ray projections. We use maximization of mutual information, an accurate similarity measure for multi-modal and mono-modal image registration tasks. However, it is known that the standard mutual information measure only takes intensity values into account without considering spatial information and its robustness is questionable. In this paper, instead of directly maximizing mutual information, we propose to use a variational approximation derived from the Kullback-Leibler bound. Spatial information is then incorporated into this variational approximation using a Markov random field model. The newly derived similarity measure has a least-squares form and can be effectively minimized by a multi-resolution Levenberg-Marquardt optimizer. Experimental results are presented on X-ray and CT datasets of a plastic phantom and a cadaveric spine segment.

  5. Novel approaches to address spectral distortions in photon counting x-ray CT using artificial neural networks

    Science.gov (United States)

    Touch, M.; Clark, D. P.; Barber, W.; Badea, C. T.

    2016-04-01

    Spectral CT using a photon-counting x-ray detector (PCXD) can potentially increase accuracy of measuring tissue composition. However, PCXD spectral measurements suffer from distortion due to charge sharing, pulse pileup, and Kescape energy loss. This study proposes two novel artificial neural network (ANN)-based algorithms: one to model and compensate for the distortion, and another one to directly correct for the distortion. The ANN-based distortion model was obtained by training to learn the distortion from a set of projections with a calibration scan. The ANN distortion was then applied in the forward statistical model to compensate for distortion in the projection decomposition. ANN was also used to learn to correct distortions directly in projections. The resulting corrected projections were used for reconstructing the image, denoising via joint bilateral filtration, and decomposition into three-material basis functions: Compton scattering, the photoelectric effect, and iodine. The ANN-based distortion model proved to be more robust to noise and worked better compared to using an imperfect parametric distortion model. In the presence of noise, the mean relative errors in iodine concentration estimation were 11.82% (ANN distortion model) and 16.72% (parametric model). With distortion correction, the mean relative error in iodine concentration estimation was improved by 50% over direct decomposition from distorted data. With our joint bilateral filtration, the resulting material image quality and iodine detectability as defined by the contrast-to-noise ratio were greatly enhanced allowing iodine concentrations as low as 2 mg/ml to be detected. Future work will be dedicated to experimental evaluation of our ANN-based methods using 3D-printed phantoms.

  6. Comparative study of two flat-panel x-ray detectors applied to small-animal imaging cone-beam micro-CT

    OpenAIRE

    2008-01-01

    Proceeding of: 2008 IEEE Nuclear Science Symposium Conference Record (NSS '08), Dresden, Germany, 19-25 Oct. 2008 This work compares two different X-ray flat-panel detectors for its use in high-speed, cone-beam CT applied to small-animal imaging. The main differences between these two devices are the scintillators and the achievable frame rate. Both devices have been tested in terms of system linearity, sensitivity, resolution, stability and noise properties, taking into account the dif...

  7. X-ray CT imaging and image-based modelling study of gas exchange in the rice rhizosphere

    Science.gov (United States)

    Affholder, Marie-Cecile; Keyes, Samuel David; Roose, Tiina; Heppell, James; Kirk, Guy

    2016-04-01

    We used X-ray computer tomography and image-based modelling to investigate CO2 uptake by rice roots growing in submerged soil, and its consequences for the chemistry and biology of the rhizosphere. From previous work, three processes are known to greatly modify the rhizophere of rice and other wetland plants: (1) oxygenation of the submerged, anoxic soil by O2 transported through the root gas channels (aerenchyma); (2) oxidation of ferrous iron and resulting accumulation of ferric oxide; and (3) pH changes due to protons formed in iron oxidation and released from the roots to balance excess intake of cations over anions. A further process, so far not much investigated, is the possibility of CO2 uptake by the roots. Large amounts of CO2 accumulate in submerged soils because CO2 formed in soil respiration escapes only slowly by diffusion through the water-saturated soil pores. There is therefore a large CO2 gradient between the soil and the aerenchyma inside the root, and CO2 may be taken up by the roots and vented to the atmosphere. The extent of this and its consequences for rhizosphere chemistry and biology are poorly understood. We grew rice plants in a submerged, strongly-reduced, Philippine rice soil contained in 10-cm diameter, 20-cm deep Perspex pots. Four-week old rice seedlings, grown in nutrient culture, were transplanted into the pots at either 1 or 4 plants per pot, planted closely together. After 3 and 4 weeks, the pots were analysed with an X-ray CT scanner (Custom Nikon/Xtek Hutch; 80 mm by 56 mm field of view and 40 μm voxel size). Gas bubbles were extracted from the data by 3D median filtering and roots using a region-growth method. The images showed prominent and abundant gas bubbles in the soil bulk, but no or very few bubbles in the soil close to roots. There was a clear relation between the absence of gas bubbles and the presence of roots, as well as an increasing concentration of bubbles with depth through the soil. Analysis of the bubbles

  8. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Final report, 14 August 1990--13 August 1994

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.D.

    1994-10-18

    Air sparged hydrocyclone (ASH) flotation is a new particle separation technology that has been developed at the University of Utah. This technology combines froth flotation principles with the flow characteristics of a hydrocyclone such that the ASH system can perform flotation separations in less than a second. This feature provides the ASH with a high specific capacity, 100 to 600 times greater than the specific capacity of conventional flotation machines. In an effort to develop a more detailed understanding of ASH flotation, multiphase flow characteristics of the air sparged hydrocyclone were studied and the relationship of these characteristics with flotation performance was investigated. This investigation was divided into four phases. In the first phase, the time-averaged multiphase flow characteristics of the ASH during its steady state operation were studied using x-ray computed tomography (x-ray CT). In this regard, a model system, mono-sized quartz flotation with dodecyl amine as collector, using a 2 in. diameter ASH unit (ASH-2C), was selected for study. Various flow regimes, namely, the air core, the froth phase, and the swirl layer, were identified and their spatial extent established for different experimental conditions by x-ray CT analysis. In the second phase, a detailed parametric study of flotation response of the ASH for the same system was carried out in order to establish the effect of various operating variables on flotation response. The findings of this phase of investigation were then correlated with the multiphase flow characteristics as revealed by x-ray CT in the first phase. Thus, the impact of various operating variables on the flow regimes, and hence, on flotation response was established.

  9. Complete blood counts, liver function tests, and chest x-rays as routine screening in early-stage breast cancer: value added or just cost?

    Science.gov (United States)

    Louie, Raphael J; Tonneson, Jennifer E; Gowarty, Minda; Goodney, Philip P; Barth, Richard J; Rosenkranz, Kari M

    2015-11-01

    Current National Comprehensive Cancer Network guidelines for breast cancer staging include pre-treatment complete blood count (CBC) and liver function tests (LFT) to screen for occult metastatic disease. To date, the relevance of these tests in detecting metastatic disease in asymptomatic women with early-stage breast cancer (Stage I/II) has not been demonstrated. Although chest x-rays are no longer recommended in the NCCN guidelines, many centers continue to include this imaging as part of their screening process. We aim to determine the clinical and financial impact of these labs and x-rays in the evaluation of early-stage breast cancer patients. A single institution IRB-approved retrospective chart review was conducted of patients with biopsy-proven invasive breast cancer treated from January 1, 2005–December 31, 2009. We collected patient demographics, clinical and pathologic staging, chest x-ray, CBC, and LFT results at the time of referral. Patients were stratified according to radiographic stage at the time of diagnosis. We obtained Medicare reimbursement fees for cost analysis. From 2005 to 2009, 1609 patients with biopsy-proven invasive breast cancer were treated at our institution. Of the 1082 patients with radiographic stage I/II disease, 27.3 % of patients had abnormal CBCs. No additional testing was performed to evaluate these abnormalities. In the early-stage population, 24.7 % of patients had elevated LFTs, resulting in 84 additional imaging studies. No metastatic disease was detected. The cost of CBC, LFTs and chest x-rays was $110.20 per patient, totaling $106,410.99. Additional tests prompted by abnormal results cost $58,143.30 over the five-year period. We found that pre-treatment CBCs, LFTs, and chest x-rays did not improve detection of occult metastatic disease but resulted in additional financial costs. Avoiding routine ordering of these tests would save the US healthcare system $25.7 million annually.

  10. SU-F-18C-13: Low-Dose X-Ray CT Reconstruction Using a Hybrid First-Order Method

    Energy Technology Data Exchange (ETDEWEB)

    Liu, L; Lin, W [Tianjin University, Tianjin (China); Jin, M [University of Texas at Arlington, Arlington, TX (United States)

    2014-06-15

    Purpose: To develop a novel reconstruction method for X-ray CT that can lead to accurate reconstruction at significantly reduced dose levels combining low X-ray incident intensity and few views of projection data. Methods: The noise nature of the projection data at low X-ray incident intensity was modeled and accounted by the weighted least-squares (WLS) criterion. The total variation (TV) penalty was used to mitigate artifacts caused by few views of data. The first order primal-dual (FOPD) algorithm was used to minimize TV in image domain, which avoided the difficulty of the non-smooth objective function. The TV penalized WLS reconstruction was achieved by alternated FOPD TV minimization and projection onto convex sets (POCS) for data fidelity constraints. The proposed FOPD-POCS method was evaluated using the FORBILD jaw phantom and the real cadaver head CT data. Results: The quantitative measures, root mean square error (RMSE) and contrast-to-noise ratio (CNR), demonstrate the superior denoising capability of WLS over LS-based TV iterative reconstruction. The improvement of RMSE (WLS vs. LS) is 15%∼21% and that of CNR is 17%∼72% when the incident counts per ray are ranged from 1×10{sup 5} to 1×10{sup 3}. In addition, the TV regularization can accurately reconstruct images from about 50 views of the jaw phantom. The FOPD-POCS reconstruction reveals more structural details and suffers fewer artifacts in both the phantom and real head images. The FOPD-POCS method also shows fast convergence at low X-ray incident intensity. Conclusion: The new hybrid FOPD-POCS method, based on TV penalized WLS, yields excellent image quality when the incident X-ray intensity is low and the projection views are limited. The reconstruction is computationally efficient since the FOPD minimization of TV is applied only in the image domain. The characteristics of FOPD-POCS can be exploited to significantly reduce radiation dose of X-ray CT without compromising accuracy for diagnosis

  11. Automated extraction method for the center line of spinal canal and its application to the spinal curvature quantification in torso X-ray CT images

    Science.gov (United States)

    Hayashi, Tatsuro; Zhou, Xiangrong; Chen, Huayue; Hara, Takeshi; Miyamoto, Kei; Kobayashi, Tatsunori; Yokoyama, Ryujiro; Kanematsu, Masayuki; Hoshi, Hiroaki; Fujita, Hiroshi

    2010-03-01

    X-ray CT images have been widely used in clinical routine in recent years. CT images scanned by a modern CT scanner can show the details of various organs and tissues. This means various organs and tissues can be simultaneously interpreted on CT images. However, CT image interpretation requires a lot of time and energy. Therefore, support for interpreting CT images based on image-processing techniques is expected. The interpretation of the spinal curvature is important for clinicians because spinal curvature is associated with various spinal disorders. We propose a quantification scheme of the spinal curvature based on the center line of spinal canal on CT images. The proposed scheme consists of four steps: (1) Automated extraction of the skeletal region based on CT number thresholding. (2) Automated extraction of the center line of spinal canal. (3) Generation of the median plane image of spine, which is reformatted based on the spinal canal. (4) Quantification of the spinal curvature. The proposed scheme was applied to 10 cases, and compared with the Cobb angle that is commonly used by clinicians. We found that a high-correlation (for the 95% confidence interval, lumbar lordosis: 0.81-0.99) between values obtained by the proposed (vector) method and Cobb angle. Also, the proposed method can provide the reproducible result (inter- and intra-observer variability: within 2°). These experimental results suggested a possibility that the proposed method was efficient for quantifying the spinal curvature on CT images.

  12. Enhancement of breast calcification visualization and detection using a modified PG method in Cone Beam Breast CT.

    Science.gov (United States)

    Liu, Jiangkun; Ning, Ruola; Cai, Weixing; Benitez, Ricardo Betancourt

    2012-01-01

    Cone Beam Breast CT is a promising diagnostic modality in breast imaging. Its isotropic 3D spatial resolution enhances the characterization of micro-calcifications in breasts that might not be easily distinguishable in mammography. However, due to dose level considerations, it is beneficial to further enhance the visualization of calcifications in Cone Beam Breast CT images that might be masked by noise. In this work, the Papoulis-Gerchberg method was modified and implemented in Cone Beam Breast CT images to improve the visualization and detectability of calcifications. First, the PG method was modified and applied to the projections acquired during the scanning process; its effects on the reconstructed images were analyzed by measuring the Modulation Transfer Function and the Noise Power Spectrum. Second, Cone Beam Breast CT images acquired at different dose levels were pre-processed using this technique to enhance the visualization of calcification. Finally, a computer-aided diagnostic algorithm was utilized to evaluate the efficacy of this method to improve calcification detectability. The results demonstrated that this technique can effectively improve image quality by improving the Modulation Transfer Function with a minor increase in noise level. Consequently, the visualization and detectability of calcifications were improved in Cone Beam Breast CT images. This technique was also proved to be useful in reducing the x-ray dose without degrading visualization and detectability of calcifications.

  13. Mean Glandular dose coefficients (DgN) for x-ray spectra used in contemporary breast imaging systems

    Science.gov (United States)

    Nosratieh, Anita; Hernandez, Andrew; Shen, Sam Z.; Yaffe, Martin J.; Seibert, J. Anthony; Boone, John M.

    2015-01-01

    Purpose To develop tables of normalized glandular dose coefficients DgN for a range of anode–filter combinations and tube voltages used in contemporary breast imaging systems. Methods Previously published mono-energetic DgN values were used with various spectra to mathematically compute DgN coefficients. The tungsten anode spectra from TASMICS were used; Molybdenum and Rhodium anode-spectra were generated using MCNPx Monte Carlo code. The spectra were filtered with various thicknesses of Al, Rh, Mo or Cu. An initial HVL calculation was made using the anode and filter material. A range of the HVL values was produced with the addition of small thicknesses of polymethyl methacrylate (PMMA) as a surrogate for the breast compression paddle, to produce a range of HVL values at each tube voltage. Using a spectral weighting method, DgN coefficients for the generated spectra were calculated for breast glandular densities of 0%, 12.5%, 25%, 37.5%, 50% and 100% for a range of compressed breast thicknesses from 3 to 8 cm. Results Eleven tables of normalized glandular dose (DgN) coefficients were produced for the following anode/filter combinations: W + 50 μm Ag, W + 500 μm Al, W + 700 μm Al, W + 200 μm Cu, W + 300 μm Cu, W + 50 μm Rh, Mo + 400 μm Cu, Mo + 30 μm Mo, Mo + 25 μm Rh, Rh + 400 μm Cu and Rh + 25 μm Rh. Where possible, these results were compared to previously published DgN values and were found to be on average less than 2% different than previously reported values. Conclusion Over 200-pages of DgN coefficients were computed for modeled x-ray system spectra that are used in a number of new breast imaging applications. The reported values were found to be in excellent agreement when compared to published values. PMID:26348995

  14. Mean glandular dose coefficients (D(g)N) for x-ray spectra used in contemporary breast imaging systems.

    Science.gov (United States)

    Nosratieh, Anita; Hernandez, Andrew; Shen, Sam Z; Yaffe, Martin J; Seibert, J Anthony; Boone, John M

    2015-09-21

    To develop tables of normalized glandular dose coefficients D(g)N for a range of anode-filter combinations and tube voltages used in contemporary breast imaging systems. Previously published mono-energetic D(g)N values were used with various spectra to mathematically compute D(g)N coefficients. The tungsten anode spectra from TASMICS were used; molybdenum and rhodium anode-spectra were generated using MCNPX Monte Carlo code. The spectra were filtered with various thicknesses of Al, Rh, Mo or Cu. An initial half value layer (HVL) calculation was made using the anode and filter material. A range of the HVL values was produced with the addition of small thicknesses of polymethyl methacrylate (PMMA) as a surrogate for the breast compression paddle, to produce a range of HVL values at each tube voltage. Using a spectral weighting method, D(g)N coefficients for the generated spectra were calculated for breast glandular densities of 0%, 12.5%, 25%, 37.5%, 50% and 100% for a range of compressed breast thicknesses from 3 to 8 cm. Eleven tables of normalized glandular dose (D(g)N) coefficients were produced for the following anode/filter combinations: W + 50 μm Ag, W + 500 μm Al, W + 700 μm Al, W + 200 μm Cu, W + 300 μm Cu, W + 50 μm Rh, Mo + 400 μm Cu, Mo + 30 μm Mo, Mo + 25 μm Rh, Rh + 400 μm Cu and Rh + 25 μm Rh. Where possible, these results were compared to previously published D(g)N values and were found to be on average less than 2% different than previously reported values.Over 200 pages of D(g)N coefficients were computed for modeled x-ray system spectra that are used in a number of new breast imaging applications. The reported values were found to be in excellent agreement when compared to published values.

  15. Influence of difference in cross-sectional dose profile in a CTDI phantom on X-ray CT dose estimation: a Monte Carlo study.

    Science.gov (United States)

    Haba, Tomonobu; Koyama, Shuji; Ida, Yoshihiro

    2014-01-01

    The longitudinal dose profile in a computed tomography dose index (CTDI) phantom had been studied by many researchers. The cross-sectional dose profile in the CTDI phantom, however, has not been studied. It is also important to understand the cross-sectional dose profile in the CTDI phantom for dose estimation in X-ray CT. In this study, the cross-sectional dose profile in the CTDI phantom was calculated by use of a Monte Carlo (MC) simulation method. A helical or a 320-detector-row cone-beam X-ray CT scanner was simulated. The cross-sectional dose profile in the CTDI phantom from surface to surface through the center point was calculated by MC simulation. The shape of the calculation region was a cylinder of 1-mm-diameter. The length of the cylinder was 23, 100, or 300 mm to represent various CT ionization chamber lengths. Detailed analyses of the energy depositions demonstrated that the cross-sectional dose profile was different in measurement methods and phantom sizes. In this study, we also focused on the validation of the weighting factor used in weighted CTDI (CTDI w ). As it stands now, the weighting factor used in CTDI w is (1/3, 2/3) for the (central, peripheral) axes. Our results showed that an equal weighting factor, which is (1/2, 1/2) for the (central, peripheral) axes, is more suitable to estimate the average cross-sectional dose when X-ray CT dose estimation is performed.

  16. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  17. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  18. 50 μm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis.

    Science.gov (United States)

    Zhao, C; Konstantinidis, A C; Zheng, Y; Anaxagoras, T; Speller, R D; Kanicki, J

    2015-12-07

    Wafer-scale CMOS active pixel sensors (APSs) have been developed recently for x-ray imaging applications. The small pixel pitch and low noise are very promising properties for medical imaging applications such as digital breast tomosynthesis (DBT). In this work, we evaluated experimentally and through modeling the imaging properties of a 50 μm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). A modified cascaded system model was developed for CMOS APS x-ray detectors by taking into account the device nonlinear signal and noise properties. The imaging properties such as modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) were extracted from both measurements and the nonlinear cascaded system analysis. The results show that the DynAMITe x-ray detector achieves a high spatial resolution of 10 mm(-1) and a DQE of around 0.5 at spatial frequencies  CMOS APS x-ray detector, image aquisition geometry and image reconstruction techniques should be considered.

  19. The impact of x-ray tube stabilization on localized radiation dose in axial CT scans: initial results in CTDI phantoms

    Science.gov (United States)

    Mathieu, Kelsey B.; McNitt-Gray, Michael F.; Cody, Dianna D.

    2016-10-01

    Rise, fall, and stabilization of the x-ray tube output occur immediately before and after data acquisition on some computed tomography (CT) scanners and are believed to contribute additional dose to anatomy facing the x-ray tube when it powers on or off. In this study, we characterized the dose penalty caused by additional radiation exposure during the rise, stabilization, and/or fall time (referred to as overscanning). A 32 cm CT dose-index (CTDI) phantom was scanned on three CT scanners: GE Healthcare LightSpeed VCT, GE Healthcare Discovery CT750 HD, and Siemens Somatom Definition Flash. Radiation exposure was detected for various x-ray tube start acquisition angles using a 10 cm pencil ionization chamber placed in the peripheral chamber hole at the phantom’s 12 o’clock position. Scan rotation time, ionization chamber location, phantom diameter, and phantom centering were varied to quantify their effects on the dose penalty caused by overscanning. For 1 s single, axial rotations, CTDI at the 12 o’clock chamber position (CTDI100, 12:00) was 6.1%, 4.0%, and 4.4% higher when the start angle of the x-ray tube was aligned at the top of the gantry (12 o’clock) versus when the start angle was aligned at 9 o’clock for the Siemens Flash, GE CT750 HD, and GE VCT scanner, respectively. For the scanners’ fastest rotation times (0.285 s for the Siemens and 0.4 s for both GE scanners), the dose penalties increased to 22.3%, 10.7%, and 10.5%, respectively, suggesting a trade-off between rotation speed and the dose penalty from overscanning. In general, overscanning was shown to have a greater radiation dose impact for larger diameter phantoms, shorter rotation times, and to peripheral phantom locations. Future research is necessary to determine an appropriate method for incorporating the localized dose penalty from overscanning into standard dose metrics, as well as to assess the impact on organ dose.

  20. Diagnosis of fibroadenoma and breast cancer: ultrasonography vs. X-ray mammography

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jong Gi; Im, Jung gi; Choi, Byung Ihn; Kim, Choo Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1993-12-15

    To evaluate the clinical value of ultrasonography in the diagnosis of fibroadenoma and carcinoma as compared with mammography, we performed a blind retrospective analysis of 85 sonograms and 40 mammograms of 85 breasts that were proved pathologically to have diseases. The lesions included 30 ductal carcinomas, 29 fibroadenomas, 14mammary dysplasias, 2 medullary carcinomas, 1 intraductal papillary carcinoma, and 9 cases of other pathology. The sonograms were reviewed in regards to the border, shape and internal echo pattern of the lesion and the shadows from the margin of the lesion. The mammograms were reviewed in regards to the parenchymal pattern, shape, margin,and calcification of the lesion. The accuracy, sensitivity, and specificity of mammography and ultrasonography in the diagnosis of fibroadenoma were 77%/92%, 40%/93%, and 100%/92%, respectively. The accuracy, sensitivity, and specificity of mammography and ultrasonography in the diagnosis of carcinoma were 85%/85%, 76%/82%, and 91%/86%,respectively. Ultrasonography is more accurate and more sensitive than mammography in the diagnosis offibroadenoma, but not in the diagnosis of carcinoma

  1. Adaptive Adjustment of Relaxation Parameters for Algebraic Reconstruction Technique and its Possible Application to Sparsity Prior X-ray CT Reconstruction

    CERN Document Server

    Saha, Sajib; Lambert, Andrew; Pickering, Mark

    2015-01-01

    In this paper, we systematically evaluate the performance of adaptive adjustment of the relaxation parameters of various iterative algorithms for X-ray CT reconstruction relying on sparsity priors. Sparsity prior has been found to be an efficient strategy in CT reconstruction where significantly fewer attenuation measurements are available. Sparsity prior CT reconstruction relies on iterative algorithms such as the algebraic reconstruction technique (ART) to produce a crude reconstruction based on which a sparse approximation is performed. Data driven adjustment of relaxation has been found to ensure better convergence than traditional relaxation for ART. In this paper, we study the performance of such data driven relaxation on a (CS) compressed sensing environment. State-of-the-art algorithms are implemented and their performance analyzed in regard to conventional and data-driven relaxation. Experiments are performed both on simulated and real environments. For the simulated case, experiments are conducted w...

  2. X-ray and CT imaging diagnosis of the ankylosing spondylitis%强直性脊柱炎的X线及CT影像学诊断

    Institute of Scientific and Technical Information of China (English)

    王凤娟; 周裕晓

    2014-01-01

    目的:探讨强直性脊柱炎的X线及 CT表现。方法收集98例强直性脊柱炎患者的 X线及CT资料。结果92例有骶髂关节表现异常,包括:早期关节面侵蚀、骨皮质局限性增厚、硬化,关节间隙正常;后期关节面呈虫蚀样改变,关节面皮质密度不规则增高,关节间隙增宽或变窄,最终关节间隙消失,骨性强直;其中12例髋关节、骶髂关节及腰椎均有不同程度异常。结论 X线及CT检查已成为诊断强直性脊柱炎的重要途径。%Objective To investigate the X-ray and CT imaging of ankylosing spondylitis. Methods X-ray and CT data of 98 patients with ankylosing spondylitis were collected and analyzed. Re-sults Sacroiliac joints in 92 cases were abnormal:in early stage,articular face was affected and the bone cortex incrassated and osteosclerosis partly,joint space was normal;in late stage,vermiform de-struction of bone was seen in articular face,the density of cortex was heighten irregular,joint space wid-en or narrow,and at last the joint space vanished,the joint ankylosed. Among them,the 12 cases of hip,sacroiliac joints and lumbar vertebra were abnormal. Conclusions X-ray and CT imaging diagnosis of ankylosing spondylitis is an important way .

  3. Analysis of CT and X-ray Observations of Cavitary Pulmonary Tuberculosis%CT与X线片对空洞型肺结核的观察分析

    Institute of Scientific and Technical Information of China (English)

    朱丽霞

    2014-01-01

    Objective To analyze the application of CT and X-ray scan in patients with cavitary tuberculosis diagnosis and treatment in summary. MethodsDuring June 2010~2012 year in November 50 cases of cavernous pulmonary tuberculosis patients in our hospital as the research object, were treated with CT and X-ray examination,check the data to compare the difference of two imaging.Results The results of CT scanning in empty, satelite lesions, bronchial dissemination, pleural thickening, lymphadenopathy and pleural effusion were detected than X-ray detection, the difference was statisticaly significant (P < 0.05); CT scanning image features as smal punctate, nodular, patchy, smal fiber cord like shadows, irregular calcification, lunginterlobular septal thickening, bronchiectasis and ground glass like exudate signs. X-ray scanning image characteristics of smal punctate, smal pieces of surrounding tuberculosis, cord like shadows.Conclusion Compared with the X-ray scanning, CTscanning has higher application value in the treatment of cavitary pulmonary tuberculosis patients, when necessary, in order to improve the accuracy of diagnosiscan be combined using the CT were diagnosed with X-ray scan.%目的:总结分析CT与X线扫描检查在空洞型肺结核患者诊断和治疗中的应用情况。方法选择2010年6月~2012年11月期间我院收治的50例空洞型肺结核患者为研究对象,均给予CT和X线扫描检查,观察比较两种影像学检查资料的差异情况。结果 CT扫描结果中空洞、卫星病灶、支气管播散、胸膜肥厚、淋巴肿大以及胸腔积液检出数明显多于X线检出数,差异具有统计学意义(P<0.05);CT扫描主要影像特征表现为小点状、结节状、小片状、纤维条索状阴影、不规则钙化影、肺小叶间隔增厚、支气管扩张以及毛玻璃样渗出征象。X线扫描主要影像特征表现为结核灶周边小点状、小片状、条索状阴影

  4. Identification of human breast pathologies by X-ray elastic scattering; Identificacao de patologias mamarias atraves do espalhamento elastico de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Andre L.C.; Antoniassi, Marcelo; Poletti, Martin E., E-mail: andre_conceicao@yahoo.com.b [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica

    2011-07-01

    In this paper we determine the scattering profiles of normal, benign and malignant human breast samples in a momentum transfer range of 0.07nm{sup -1} {<=}q{<=}70.55nm{sup -1}, resulted from combining WAXS (wide angle x-ray scattering) and SAXS (small angle x-ray scattering) data. The results showed considerable differences between the scattering profiles of each tissue type. Based on this fact, some parameters, representing structural features, were extracted from these scattering profiles and submitted to a discriminant analysis. From statistical analysis, the ratio between the peak intensities at q=19.8nm{sup -1} and q=13.9nm{sup -1} and the intensity of third order axial collagen peak arose as two potentials breast tissue classifiers and, from combining them it was possible differentiate among normal, benign and malignant lesions. (author)

  5. Effective incorporating spatial information in a mutual information based 3D-2D registration of a CT volume to X-ray images.

    Science.gov (United States)

    Zheng, Guoyan

    2010-10-01

    This paper addresses the problem of estimating the 3D rigid poses of a CT volume of an object from its 2D X-ray projection(s). We use maximization of mutual information, an accurate similarity measure for multi-modal and mono-modal image registration tasks. However, it is known that the standard mutual information measures only take intensity values into account without considering spatial information and their robustness is questionable. In this paper, instead of directly maximizing mutual information, we propose to use a variational approximation derived from the Kullback-Leibler bound. Spatial information is then incorporated into this variational approximation using a Markov random field model. The newly derived similarity measure has a least-squares form and can be effectively minimized by a multi-resolution Levenberg-Marquardt optimizer. Experiments were conducted on datasets from two applications: (a) intra-operative patient pose estimation from a limited number (e.g. 2) of calibrated fluoroscopic images, and (b) post-operative cup orientation estimation from a single standard X-ray radiograph with/without gonadal shielding. The experiment on intra-operative patient pose estimation showed a mean target registration accuracy of 0.8mm and a capture range of 11.5mm, while the experiment on estimating the post-operative cup orientation from a single X-ray radiograph showed a mean accuracy below 2 degrees for both anteversion and inclination. More importantly, results from both experiments demonstrated that the newly derived similarity measures were robust to occlusions in the X-ray image(s).

  6. Improving the quality of reconstructed X-ray CT images of polymer gel dosimeters: zero-scan coupled with adaptive mean filtering.

    Science.gov (United States)

    Kakakhel, M B; Jirasek, A; Johnston, H; Kairn, T; Trapp, J V

    2017-02-06

    This study evaluated the feasibility of combining the 'zero-scan' (ZS) X-ray computed tomography (CT) based polymer gel dosimeter (PGD) readout with adaptive mean (AM) filtering for improving the signal to noise ratio (SNR), and to compare these results with available average scan (AS) X-ray CT readout techniques. NIPAM PGD were manufactured, irradiated with 6 MV photons, CT imaged and processed in Matlab. AM filter for two iterations, with 3 × 3 and 5 × 5 pixels (kernel size), was used in two scenarios (a) the CT images were subjected to AM filtering (pre-processing) and these were further employed to generate AS and ZS gel images, and (b) the AS and ZS images were first reconstructed from the CT images and then AM filtering was carried out (post-processing). SNR was computed in an ROI of 30 × 30 for different pre and post processing cases. Results showed that the ZS technique combined with AM filtering resulted in improved SNR. Using the previously-recommended 25 images for reconstruction the ZS pre-processed protocol can give an increase of 44% and 80% in SNR for 3 × 3 and 5 × 5 kernel sizes respectively. However, post processing using both techniques and filter sizes introduced blur and a reduction in the spatial resolution. Based on this work, it is possible to recommend that the ZS method may be combined with pre-processed AM filtering using appropriate kernel size, to produce a large increase in the SNR of the reconstructed PGD images.

  7. Comparative study on X- ray mammography and MRI in diagnosing breast cancer%乳腺癌X线与MRI诊断价值比较分析

    Institute of Scientific and Technical Information of China (English)

    渠红; 鲍春生; 邢丽

    2011-01-01

    目的:比较X线及MRI两种影像学检查方法对于乳腺癌的诊断价值.方法:回顾分析48例经手术病理证实的乳腺癌患者的MRI及X线检查资料,进行对比分析.结果:MRI对于乳腺癌病灶的检出高于X线摄影,但存在假阳性,对于判断病变范围及淋巴结转移等方面MRI具有较大价值.结论:X线摄影与MRI联合应用有助于提高乳腺癌的诊断准确率.%Objective:To compare the capabilities of MRI and X - ray mammography in diagnosing breast cancer. Methods ; A retrospective study of 48 breast cancer proved by pathology was performed, the diagnosing results of MRI and X - ray mammography were compared with that of histopathology.Results : MRI imaging was superior to mammography , but it exist false - positive ; MRI imaging was much valuable for lymph nodes metastases and assesament of lesion extent.Conclusion : X - ray mammography in combination with MRI is helpful in the diagnasis of breast cancer ,the sensitivity and specificity was enhanced when compared to that of single.

  8. Scaling-law for the energy dependence of anatomic power spectrum in dedicated breast CT

    Energy Technology Data Exchange (ETDEWEB)

    Vedantham, Srinivasan; Shi, Linxi; Glick, Stephen J.; Karellas, Andrew [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States)

    2013-01-15

    Purpose: To determine the x-ray photon energy dependence of the anatomic power spectrum of the breast when imaged with dedicated breast computed tomography (CT). Methods: A theoretical framework for scaling the empirically determined anatomic power spectrum at one x-ray photon energy to that at any given x-ray photon energy when imaged with dedicated breast CT was developed. Theory predicted that when the anatomic power spectrum is fitted with a power curve of the form k f{sup -{beta}}, where k and {beta} are fit coefficients and f is spatial frequency, the exponent {beta} would be independent of x-ray photon energy (E), and the amplitude k scales with the square of the difference in energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues. Twenty mastectomy specimens based numerical phantoms that were previously imaged with a benchtop flat-panel cone-beam CT system were converted to 3D distribution of glandular weight fraction (f{sub g}) and were used to verify the theoretical findings. The 3D power spectrum was computed in terms of f{sub g} and after converting to linear attenuation coefficients at monoenergetic x-ray photon energies of 20-80 keV in 5 keV intervals. The 1D power spectra along the axes were extracted and fitted with a power curve of the form k f{sup -{beta}}. The energy dependence of k and {beta} were analyzed. Results: For the 20 mastectomy specimen based numerical phantoms used in the study, the exponent {beta} was found to be in the range of 2.34-2.42, depending on the axis of measurement. Numerical simulations agreed with the theoretical predictions that for a power-law anatomic spectrum of the form k f{sup -{beta}}, {beta} was independent of E and k(E) =k{sub 1}[{mu}{sub g}(E) -{mu}{sub a}(E)]{sup 2}, where k{sub 1} is a constant, and {mu}{sub g}(E) and {mu}{sub a}(E) represent the energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues, respectively. Conclusions: Numerical

  9. Validity of Fusion Imaging of Hamster Heart obtained by Fluorescent and Phase-Contrast X-Ray CT with Synchrotron Radiation

    Science.gov (United States)

    Wu, J.; Takeda, T.; Lwin, Thet Thet; Huo, Q.; Sunaguchi, N.; Murakami, T.; Mouri, S.; Nasukawa, S.; Fukami, T.; Yuasa, T.; Hyodo, K.; Hontani, H.; Minami, M.; Akatsuka, T.

    2007-01-01

    Fluorescent X-ray CT (FXCT) to depict functional information and phase-contrast X-ray CT (PCCT) to demonstrate morphological information are being developed to analyze the disease model of small animal. To understand the detailed pathological state, integration of both functional and morphological image is very useful. The feasibility of image fusion between FXCT and PCCT were examined by using ex-vivo hearts injected fatty acid metabolic agent (127I-BMIPP) in normal and cardiomyopathic hamsters. Fusion images were reconstructed from each 3D image of FXCT and PCCT. 127I-BMIPP distribution within the heart was clearly demonstrated by FXCT with 0.25 mm spatial resolution. The detailed morphological image was obtained by PCCT at about 0.03 mm spatial resolution. Using image integration technique, metabolic abnormality of fatty acid in cardiomyopathic myocardium was easily recognized corresponding to anatomical structures. Our study suggests that image fusion provides important biomedical information even in FXCT and PCCT imaging.

  10. In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography (CT) and Light Microscopy (LM) Correlated with Scanning Electron Microscopy (SEM).

    Science.gov (United States)

    Meyer, Jörg; Thomas, Christian; Tappe, Frank; Ogbazghi, Tekie

    2016-06-16

    In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of micro-characterization, plays an important role. Commonly, different techniques like X-ray computed tomography (CT), light microscopy (LM) and scanning electron microscopy (SEM) are used separately. Similarly, the results have to be treated for each technique independently. Here a comprehensive study is shown which demonstrates the potentials leveraged by linking CT, LM and SEM. In depth characterization is performed on a white emitting LED, which can be operated throughout all characterization steps. Major advantages are: planned preparation of defined cross sections, correlation of optical properties to structural and compositional information, as well as reliable identification of different functional regions. This results from the breadth of information available from identical regions of interest (ROIs): polarization contrast, bright and dark-field LM images, as well as optical images of the LED cross section in operation. This is supplemented by SEM imaging techniques and micro-analysis using energy dispersive X-ray spectroscopy.

  11. Reconstruction of Intima and Adventitia Models into a State Undeformed by a Catheter by Using CT, IVUS, and Biplane X-Ray Angiogram Images

    Directory of Open Access Journals (Sweden)

    Jinwon Son

    2017-01-01

    Full Text Available The number of studies on blood flow analysis using fluid-structure interaction (FSI analysis is increasing. Though a 3D blood vessel model that includes intima and adventitia is required for FSI analysis, there are difficulties in generating it using only one type of medical imaging. In this paper, we propose a 3D modeling method for accurate FSI analysis. An intravascular ultrasound (IVUS image is used with biplane X-ray angiogram images to calculate the position and orientation of the blood vessel. However, these images show that the blood vessel is deformed by the catheter inserted into the blood vessel for IVUS imaging. To eliminate such deformation, a CT image was added and the two models were registered. First, a 3D model of the undeformed intima was generated using a CT image. In the second stage, a model of intima and adventitia deformed by the catheter was generated by combining the IVUS image and the X-ray angiogram images. A 3D model of intima and adventitia with the deformation caused by insertion of the catheter eliminated was generated by matching these 3D blood vessel models in different states. In addition, a 3D blood vessel model including bifurcation was generated using the proposed method.

  12. Evaluation of multiple-scale 3D characterization for coal physical structure with DCM method and synchrotron X-ray CT.

    Science.gov (United States)

    Wang, Haipeng; Yang, Yushuang; Yang, Jianli; Nie, Yihang; Jia, Jing; Wang, Yudan

    2015-01-01

    Multiscale nondestructive characterization of coal microscopic physical structure can provide important information for coal conversion and coal-bed methane extraction. In this study, the physical structure of a coal sample was investigated by synchrotron-based multiple-energy X-ray CT at three beam energies and two different spatial resolutions. A data-constrained modeling (DCM) approach was used to quantitatively characterize the multiscale compositional distributions at the two resolutions. The volume fractions of each voxel for four different composition groups were obtained at the two resolutions. Between the two resolutions, the difference for DCM computed volume fractions of coal matrix and pores is less than 0.3%, and the difference for mineral composition groups is less than 0.17%. This demonstrates that the DCM approach can account for compositions beyond the X-ray CT imaging resolution with adequate accuracy. By using DCM, it is possible to characterize a relatively large coal sample at a relatively low spatial resolution with minimal loss of the effect due to subpixel fine length scale structures.

  13. Evaluation of Multiple-Scale 3D Characterization for Coal Physical Structure with DCM Method and Synchrotron X-Ray CT

    Directory of Open Access Journals (Sweden)

    Haipeng Wang

    2015-01-01

    Full Text Available Multiscale nondestructive characterization of coal microscopic physical structure can provide important information for coal conversion and coal-bed methane extraction. In this study, the physical structure of a coal sample was investigated by synchrotron-based multiple-energy X-ray CT at three beam energies and two different spatial resolutions. A data-constrained modeling (DCM approach was used to quantitatively characterize the multiscale compositional distributions at the two resolutions. The volume fractions of each voxel for four different composition groups were obtained at the two resolutions. Between the two resolutions, the difference for DCM computed volume fractions of coal matrix and pores is less than 0.3%, and the difference for mineral composition groups is less than 0.17%. This demonstrates that the DCM approach can account for compositions beyond the X-ray CT imaging resolution with adequate accuracy. By using DCM, it is possible to characterize a relatively large coal sample at a relatively low spatial resolution with minimal loss of the effect due to subpixel fine length scale structures.

  14. Algorithm for X-ray scatter, beam-hardening, and beam profile correction in diagnostic (kilovoltage) and treatment (megavoltage) cone beam CT.

    Science.gov (United States)

    Maltz, Jonathan S; Gangadharan, Bijumon; Bose, Supratik; Hristov, Dimitre H; Faddegon, Bruce A; Paidi, Ajay; Bani-Hashemi, Ali R

    2008-12-01

    Quantitative reconstruction of cone beam X-ray computed tomography (CT) datasets requires accurate modeling of scatter, beam-hardening, beam profile, and detector response. Typically, commercial imaging systems use fast empirical corrections that are designed to reduce visible artifacts due to incomplete modeling of the image formation process. In contrast, Monte Carlo (MC) methods are much more accurate but are relatively slow. Scatter kernel superposition (SKS) methods offer a balance between accuracy and computational practicality. We show how a single SKS algorithm can be employed to correct both kilovoltage (kV) energy (diagnostic) and megavoltage (MV) energy (treatment) X-ray images. Using MC models of kV and MV imaging systems, we map intensities recorded on an amorphous silicon flat panel detector to water-equivalent thicknesses (WETs). Scattergrams are derived from acquired projection images using scatter kernels indexed by the local WET values and are then iteratively refined using a scatter magnitude bounding scheme that allows the algorithm to accommodate the very high scatter-to-primary ratios encountered in kV imaging. The algorithm recovers radiological thicknesses to within 9% of the true value at both kV and megavolt energies. Nonuniformity in CT reconstructions of homogeneous phantoms is reduced by an average of 76% over a wide range of beam energies and phantom geometries.

  15. TU-EF-207-05: Dedicated Cone-beam Breast CT

    Energy Technology Data Exchange (ETDEWEB)

    Vedantham, S. [Univ. of Massachusetts Medical School (United States)

    2015-06-15

    mode due to lower photon fluence per projection. This may require fast-frame acquisition and symmetric or asymmetric pixel binning in some systems. Recent studies investigated the performance of increased conversion layer thickness for contrast-enhanced imaging of the breast in dual-energy acquisition mode. In other direct conversion detectors operating in the avalanche mode, sensitivities close to the single photon response are also explored for mammography and breast tomosynthesis. The potential advantages and challenges of this approach are described. Dedicated breast CT brings x-ray imaging of the breast to true tomographic 3D imaging. It can eliminate the tissue superposition problem and does not require physical compression of the breast. Using cone beam geometry and a flat-panel detector, several hundred projections are acquired and reconstructed to near isotropic voxels. Multiplanar reconstruction facilitates viewing the breast volume in any desired orientation. Ongoing clinical studies, the current state-of-the art, and research to advance the technology are described. Learning Objectives: To understand the ongoing developments in x-ray imaging of the breast To understand the approaches and applications of spectral mammography To understand the potential advantages of distributed x-ray source arrays for digital breast tomosynthesis To understand the ongoing developments in detector technology for digital mammography and breast tomosynthesis To understand the current state-of-the-art for dedicated cone-beam breast CT and research to advance the technology. Research collaboration with Koning Corporation.

  16. X-ray and CT Image Analysis of Pelvic Fractures%骨盆骨折的X线平片与CT影像分析研究

    Institute of Scientific and Technical Information of China (English)

    祝华强; 刘斯润; 邱剑; 罗东梅; 周德明

    2011-01-01

    Objective: To summarize X-ray and CT imaging characteristic for pelvic fracture and analyze the missed diagnosis reason. Methods: Retrospectively analyzed 620 cases of pelvic fracture with X-ray and spiral CT image data, to compare detection rate and analyze the missed diagnosis reason. Results: There were 1036 fractures in quantity and 38 dearticulation of 620 cases. 255 iliac fractures, 226 acetabular fractures, 99 sacral and coccyx fractures, 341 pubic upper and lower branches fractures, 115 ischia fratures, 20 cases of dislocation of hip joint and sacroiliac joint. About 169 micro-fractures, 1 post dislocation of hip joint, 5 mild dislocations of sacroiliac joint and 3 mild separation of pubic symphysis were mis-diagnosed by X-ray. Fracture detection rates of X-ray plain is 83.7% and dislocation detection rates is 76.3%; Among 226 acetabular fractures, X-ray plain and SSD mis-diagnosed about 61 and 20 fractures separately. The detection rate of X-ray plain and SSD of fracture was 73.0 % and 91.2%. In 99 sacral and coccyx fractures, X-ray plain and SSD mis-diagnosed about 48 and 11 cases,the fracture-dislocation detection rate was 56.0% and 89.g% separately. Through X2 examination, X-ray plain and CT of pelvic fracture had differences in statistically (p <0.05). There's no statistical difference between SCT/MPR and SSD (p > 0.05 ). Conclusion: The performance of spiral CT is better than X-ray examination in the detection of pelvic fracture. Spiral CT with MPR and SSD could clearly reveal the detail of fracture, improved the preoperative diagnosis and facilitated surgical treatment.%目的:总结骨盆骨折的X线和CT影像学特点并探讨漏诊原因.方法:回顾性对比分析620例同时有X线平片及螺旋CT检查的骨盆骨折影像资料,比较检出率,分析漏诊因素.结果:620例共有骨盆骨折1036处及关节脱位/分离38处,其中髂骨骨折255处,髋臼骨折226处,骶尾骨骨折99处,耻骨上下支骨折341

  17. SU-E-T-143: Effect of X-Ray and Cone Beam CT Reconstruction Parameters On Estimation of Bone Volume of Mice Used in Aging Research

    Energy Technology Data Exchange (ETDEWEB)

    Russ, M; Pang, M; Troen, B; Rudin, S; Ionita, C [University at Buffalo, Buffalo, NY (United States)

    2014-06-01

    Purpose: To investigate the variations in bone volume calculations in mice involved in aging research when changing cone beam micro-CT x-ray and reconstruction parameters. Methods: Mouse spines were placed on an indexed turn table that rotated 0.5° per projection and imaged by a self-built micro CT machine containing a CCD-based high-resolution x-ray detector. After the full 360° rotation data set of object images was obtained, a standard filtered back-projection cone beam reconstruction was performed. Four different kVp's between 40–70 kVp in 10kVp increments were selected. For each kVp two mAs settings were used. Each acquisition was reconstructed using two voxel sizes (12 and 25μm) and two step angles, 0.5° and 1°, respectively. A LabView program was written to determine the total bone volume contained in the mouse's total spine volume (bone plus gaps) as a measure of spine health. First, the user selected the desired 512×512 reconstruction to view the whole spine volume which was then used to select a gray-level threshold that allowed for viewing of the bone structure, then another threshold to include gaps. The program returned bone volume, bone × gap volume, and their ratio, BVF. Results: The calculated bone volume fractions were compared as a function of tube potential. Cases with 25μm slice thickness showed trials with lower kVp's had greater image contrast, which resulted in higher calculated bone volume fractions. Cases with 12μm reconstructed slice thickness were significantly noisier, and showed no clear maximum BVF. Conclusion: Using the projection images and reconstructions acquired from the micro CT, it can be shown that the micro-CT x-ray and reconstruction parameters significantly affect the total bone volume calculations. When comparing mice cohorts treated with different therapies researchers need to be aware of such details and use volumes which were acquired and processed in identical conditions.

  18. Tissue Visualization Using X-Ray Dark-Field Imaging towards Pathological Goal

    Science.gov (United States)

    Ando, Masami; Chikaura, Yoshinori; Endo, Tokiko; Gupta, Rajiv; Huo, Qingkai; Hyodo, Kazuyuki; Ichihara, Shu; Mori, Kensaku; Nakao, Yuki; Ohura, Norihiko; Sunaguchi, Naoki; Sugiyama, Hiroshi; Suzuki, Yoshifumi; Wu, Yanlin; Yuasa, Tetsuya; Xiaowei, Zhang

    2013-03-01

    In XDFI (x-ray dark-field imaging) LAA (Laue-case angle analyzer) simultaneously provides two x-ray images; one corresponds to a FD forward diffracted beam and a separate D diffracted beam. When this is applied to biomedical specimens x-ray images are very high contrast and very high spatial resolution. We constructed XDFI system at the vertical wiggler beamline BL-14C in KEK Photon Factory and performed imaging experiment of breast tissues and an excised human femoral artery. In this paper, we discuss a tissue visualization and pathological goal using 2D, 3D-CT and 2.5D image (tomosynthesis) with XDFI.

  19. 乳腺高频钼靶X线联合乳管镜筛查乳腺癌%Ductoscopy combined X-ray mammography for breast cancer screening

    Institute of Scientific and Technical Information of China (English)

    冯立文; 黄茂伦; 廖女珠; 李誉

    2013-01-01

    Objective Understand shunde Uistrict Foshan City,Guangdong Province in the incidence of breast cancer in women.Methods The joint selectivity ductoscopy examination of the clinical breast examination screening,breast X-ray radiography examination from March 2011 to January 2013,Shunde District,FoShan City,Guangdong Provice,3 600 bladder than 40 years old woman with breast cancer screening.Results Three thousand six hundred women were found in 10 cases of breast cancer,the detection rate of 278/100 000 (10/3 600).Breast clinical examination found 1 313 cases of breast abnormalities,142 cases of breast lumps,nipple discharge line fiberoptic ductoscopy to cheek the 100 cases,X-ray radiography examination of four and more than 72 cases,accounted for a total of 45.19% of the screening population (1 627/3 600).Conclusions Joint ductoscopy X-ray radiography examination of breast cancer screening in the normal population can help to detect early breast cancer,and to provide the basis for early clinical treatment.%目的 了解广东省佛山市顺德区城市妇女乳腺高频钼靶X线联合乳管镜筛查乳腺癌的情况.方法 2011年3月-2013年1月采用临床乳腺检查初筛,以及乳腺高频钼靶X线检查联合选择性乳管镜检查,对广东省佛山市顺德区3 600例40岁以上妇女进行了乳腺癌筛查.结果 3 600例妇女共检出乳腺癌10例,检出率为278/10万(10/3600).乳腺临床检查中发现乳腺异常1 313例、乳腺肿块142例、乳头溢液行乳管镜检查100例;乳腺高频钼靶X线检查4级及以上者72例,总共占筛查人群的45.19%(1 627/3 600).结论 通过乳管镜联合乳腺高频钼靶X线片在正常人群中进行乳腺癌筛查,有助于发现早期乳腺癌,为临床早期治疗提供依据.

  20. A cascaded model of spectral distortions due to spectral response effects and pulse pileup effects in a photon-counting x-ray detector for CT

    Energy Technology Data Exchange (ETDEWEB)

    Cammin, Jochen, E-mail: jcammin1@jhmi.edu, E-mail: ktaguchi@jhmi.edu; Taguchi, Katsuyuki, E-mail: jcammin1@jhmi.edu, E-mail: ktaguchi@jhmi.edu [Division of Medical Imaging Physics, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287 (United States); Xu, Jennifer [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21287 (United States); Barber, William C.; Iwanczyk, Jan S.; Hartsough, Neal E. [DxRay, Inc., Northridge, California 91324 (United States)

    2014-04-15

    Purpose: Energy discriminating, photon-counting detectors (PCDs) are an emerging technology for computed tomography (CT) with various potential benefits for clinical CT. The photon energies measured by PCDs can be distorted due to the interactions of a photon with the detector and the interaction of multiple coincident photons. These effects result in distorted recorded x-ray spectra which may lead to artifacts in reconstructed CT images and inaccuracies in tissue identification. Model-based compensation techniques have the potential to account for the distortion effects. This approach requires only a small number of parameters and is applicable to a wide range of spectra and count rates, but it needs an accurate model of the spectral distortions occurring in PCDs. The purpose of this study was to develop a model of those spectral distortions and to evaluate the model using a PCD (model DXMCT-1; DxRay, Inc., Northridge, CA) and various x-ray spectra in a wide range of count rates. Methods: The authors hypothesize that the complex phenomena of spectral distortions can be modeled by: (1) separating them into count-rate independent factors that we call the spectral response effects (SRE), and count-rate dependent factors that we call the pulse pileup effects (PPE), (2) developing separate models for SRE and PPE, and (3) cascading the SRE and PPE models into a combined SRE+PPE model that describes PCD distortions at both low and high count rates. The SRE model describes the probability distribution of the recorded spectrum, with a photo peak and a continuum tail, given the incident photon energy. Model parameters were obtained from calibration measurements with three radioisotopes and then interpolated linearly for other energies. The PPE model used was developed in the authors’ previous work [K. Taguchi et al., “Modeling the performance of a photon counting x-ray detector for CT: Energy response and pulse pileup effects,” Med. Phys. 38(2), 1089–1102 (2011

  1. 颈椎损伤的X线与CT诊断%The Diagnosis of X-ray and CT for Cervical Spine Injury

    Institute of Scientific and Technical Information of China (English)

    黄金龙; 周鹏; 高雪梅

    2010-01-01

    目的 探讨常规X线和CT扫描对颈椎损伤的诊断价值.方法 对50例X线和CT诊断为颈椎损伤的病例进行分析.结果 本组50例,受损椎体共60个.低位颈椎骨折并(或)脱位27例,寰椎骨折9例,寰枢椎脱位8例,枢椎骨折6例.X线平片显示椎体后缘联线异常24例,CT片根据脊柱三柱结构诊断不稳定骨折28例,椎管0度狭窄22例,1度狭窄17例,2度狭窄8例,3度狭窄3例.外伤性颈椎间盘脱出10例.结论 对于颈椎损伤的患者,应常规行X线和CT扫描检查,以利于为临床提供更全面可靠的信息.CT能对颈椎损伤做出较全面、准确的诊断,有利于治疗方案的选择,可作为颈椎损伤临床术前诊断和治疗的影像学检查的首选方法.%Objective To evaluate the diagnosis value of X-ray and CT for cervical spine injury. Methods The clinical data of 50 cases of vertebral spine injuries which were neglected due to missed diagnosis were analyzed retrospectively. Results 50 cases with cervical spine injury, among of them, 27 cases with fracture and/(or) dislocation of the lower cervical vertebrae,9 cases had atlantal fracture,8 cases had atlantoaxial dislocation and 6 cases had the axoid fracture. 24 cases showed abnormality in the lines of vertebral posterior border in the X-ray plain films. 28 cases were diagnosed instabitity,22 cases vertebral canal 0° stricture, 17 cases Ⅰ°stricture, 8 cases Ⅱ°stricture,3 cases Ⅲ° stricture were diagnosed according CT films. 10 cases traumatic cervicales disc herniation. Conclusion X-ray and CT have their own localization for injured cervical vertebraes. We must perform X-ray and CT examination in order to provide overall and reliable information for clinical diagnosis. CT is becoming an indispensible and best modality of choices in the diagnosis of atloaxoid injuries helpful for the surgeon to decide clinical management. The advantages of CT are suggested that this diagnostic modality may be the standard method for

  2. Chest X Ray?

    Science.gov (United States)

    ... this page from the NHLBI on Twitter. Chest X Ray A chest x ray is a fast and painless imaging test ... tissue scarring, called fibrosis. Doctors may use chest x rays to see how well certain treatments are ...

  3. X-Rays

    Science.gov (United States)

    X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat ...

  4. Micromechanical Time-Lapse X-ray CT Study of Fatigue Damage in Uni-Directional Fibre Composites

    DEFF Research Database (Denmark)

    Jespersen, Kristine Munk; Lowe, Tristan; Withers, Philip J.

    2015-01-01

    This study considers fatigue damage evolution in a uni-directional (UD) glass fibre composite used for wind turbine blades which is manufactured from a non-crimp fabric. It is the initial part of a time-lapse study where the damage progression is followed in a sample during a fatigue test....... In the current study 3D X-ray Computed Tomography (XCT) is used to characterise the fatigue damage in the material at three different stages of the fatigue life of a tension-tension fatigue test. 3D XCT is performed on rectangular samples (4x4x110mm) cut out from pre-fatigued full-size fatigue test specimens...

  5. X-ray flat-panel imager (FPI)-based cone-beam volume CT (CBVCT) under a circle-plus-two-arc data acquisition orbit

    Science.gov (United States)

    Tang, Xiangyang; Ning, Ruola; Yu, Rongfeng; Conover, David L.

    2001-06-01

    The potential of cone beam volume CT (CBVCT) to improve the data acquisition efficiency for volume tomographic imaging is well recognized. A novel x-ray FPI based CBVCT prototype and its preliminary performance evaluation are presented in this paper. To meet the data sufficiency condition, the CBVCT prototype employs a circle-plus-two-arc orbit accomplished by a tiltable circular gantry. A cone beam filtered back-projection (CB-FBP) algorithm is derived for this data acquisition orbit, which employs a window function in the Radon domain to exclude the redundancy between the Radon information obtained from the circular cone beam (CB) data and that from the arc CB data. The number of projection images along the circular sub-orbit and each arc sub-orbit is 512 and 43, respectively. The reconstruction exactness of the prototype x-ray FPI based CBVCT system is evaluated using a disc phantom in which seven acrylic discs are stacked at fixed intervals. Images reconstructed with this algorithm show that both the contrast and geometric distortion existing in the disc phantom images reconstructed by the Feldkamp algorithm are substantially reduced. Meanwhile, the imaging performance of the prototype, such as modulation transfer function (MTF) and low contrast resolution, are quantitatively evaluated in detail through corresponding phantom studies. Furthermore, the capability of the prototype to reconstruct an ROI within a longitudinally unbounded object is verified. The results obtained from this preliminary performance evaluation encourage an expectation of medical applications of the x-ray FPI based CBVCT under the circle-plus-two-arc data acquisition, particularly the application in image-guided interventional procedures and radiotherapy where the movement of a patient table is to be avoided.

  6. Experimental Investigation of the Variation of Concrete Pores under the Action of Freeze-Thaw Cycles by Using X-Ray CT

    Directory of Open Access Journals (Sweden)

    Jie Yuan

    2014-01-01

    Full Text Available The variation of concrete pores under the action of freeze-thaw cycles was investigated experimentally by using the X-ray CT. Firstly, the statistical characteristics of pores of concrete specimens were obtained by using the X-ray image analysis. Secondly, the variation of porosity and pore volume of concrete pores were analyzed and discussed by comparing with above characteristics. Thirdly, the failure process of the concrete specimens acted by the freeze-thaw cycles was investigated by scanning the interior of concrete specimens. The results showed that the pore volumes of concrete pores whose volumes were located at the interval [0.5 mm3, 20 mm3] have no big variation in both the amounts and volume of concrete pores, while others were found to have huge change during the process of experiment. The extent of damage acted by the repeated freezing and thawing gradually ranged from surface to complete disintegration of the interior of concrete specimens after 30 cycles of freeze-thaw acting.

  7. Application of sensitive, high-resolution imaging at a commercial lab-based X-ray micro-CT system using propagation-based phase retrieval.

    Science.gov (United States)

    Bidola, P; Morgan, K; Willner, M; Fehringer, A; Allner, S; Prade, F; Pfeiffer, F; Achterhold, K

    2017-02-09

    Several dedicated commercial lab-based micro-computed tomography (μCT) systems exist, which provide high-resolution images of samples, with the capability to also deliver in-line phase contrast. X-ray phase contrast is particularly beneficial when visualizing very small features and weakly absorbing samples. The raw measured projections will include both phase and absorption effects. Extending our previous work that addressed the optimization of experimental conditions at the commercial ZEISS Xradia 500 Versa system, single-distance phase-contrast imaging is demonstrated on complex biological and material samples. From data captured at this system, we demonstrate extraction of the phase signal or the correction of the mixed image for the phase shift, and show how this procedure increases the contrast and removes artefacts. These high-quality images, measured without the use of a synchrotron X-ray source, demonstrate that highly sensitive, micrometre-resolution imaging of 3D volumes is widely accessible using commercially advanced laboratory devices.

  8. Iodine contrast cone beam CT imaging of breast cancer

    Science.gov (United States)

    Partain, Larry; Prionas, Stavros; Seppi, Edward; Virshup, Gary; Roos, Gerhard; Sutherland, Robert; Boone, John

    2007-03-01

    An iodine contrast agent, in conjunction with an X-ray cone beam CT imaging system, was used to clearly image three, biopsy verified, cancer lesions in two patients. The lesions were approximately in the 10 mm to 6 mm diameter range. Additional regions were also enhanced with approximate dimensions down to 1 mm or less in diameter. A flat panel detector, with 194 μm pixels in 2 x 2 binning mode, was used to obtain 500 projection images at 30 fps with an 80 kVp X-ray system operating at 112 mAs, for an 8-9 mGy dose - equivalent to two view mammography for these women. The patients were positioned prone, while the gantry rotated in the horizontal plane around the uncompressed, pendant breasts. This gantry rotated 360 degrees during the patient's 16.6 sec breath hold. A volume of 100 cc of 320 mg/ml iodine-contrast was power injected at 4 cc/sec, via catheter into the arm vein of the patient. The resulting 512 x 512 x 300 cone beam CT data set of Feldkamp reconstructed ~(0.3 mm) 3 voxels were analyzed. An interval of voxel contrast values, characteristic of the regions with iodine contrast enhancement, were used with surface rendering to clearly identify up to a total of 13 highlighted volumes. This included the three largest lesions, that were previously biopsied and confirmed to be malignant. The other ten highlighted regions, of smaller diameters, are likely areas of increased contrast trapping unrelated to cancer angiogenesis. However the technique itself is capable of resolving lesions that small.

  9. Material-specific imaging system using energy-dispersive X-ray diffraction and spatially resolved CdZnTe detectors with potential application in breast imaging

    Science.gov (United States)

    Barbes, Damien; Tabary, Joachim; Paulus, Caroline; Hazemann, Jean-Louis; Verger, Loïck

    2017-03-01

    This paper presents a coherent X-ray-scattering imaging technique using a multipixel energy-dispersive system. Without any translation, the technique produces specific 1D image from data recorded by a single CdZnTe detector pixel using subpixelation techniques. The method is described in detail, illustrated by a simulation and then experimentally validated. As the main considered application of our study is breast imaging, this validation involves 2D imaging of a phantom made of plastics mimicking breast tissues. The results obtained show that our system can specifically image the phantom using a single detector pixel. For the moment, in vivo breast imaging applications remain difficult, as the dose delivered by the system is too high, but some adjustments are considered for further work.

  10. Case of neuro-Behcet syndrome with brainstem lesions confirmed by MRI. Relationship between X-ray CT and MRI findings and neurological symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Takizawa, Shunya; Haida, Munetaka; Ohsuga, Hitoshi; Takagi, Shigeharu; Shinohara, Yukito

    1988-03-01

    A 49-year-old man presented with a 30-year history of oral and genital aphthous ulcers and joint pain. One day before his admission he developed double vision and weakness in the right extremities. Neurological examination revealed right 5th nerve palsy, left 6th to 18th nerve palsy, left Horner's sign, and motor and sensory impairment in the right upper and lower extremities. X-ray CT showed diffuse, weak, low-density areas in the brainstem. T1 weighted images showed low signals in the left side of the mid-pons, the left tegmentum and the right basis of the upper pons, and the left tegmentum of the midbrain. T2 weighted images showed high signals in the whole pons and the left side of the midbrain. MRI allowed the differentiation of reversible lesions, such as brain edema, and irreversible lesions, such as necrosis and demyelination of the tissue. (Namekawa, K.).

  11. Investigating lithium-ion battery materials during overcharge-induced thermal runaway: an operando and multi-scale X-ray CT study.

    Science.gov (United States)

    Finegan, Donal P; Scheel, Mario; Robinson, James B; Tjaden, Bernhard; Di Michiel, Marco; Hinds, Gareth; Brett, Dan J L; Shearing, Paul R

    2016-11-16

    Catastrophic failure of lithium-ion batteries occurs across multiple length scales and over very short time periods. A combination of high-speed operando tomography, thermal imaging and electrochemical measurements is used to probe the degradation mechanisms leading up to overcharge-induced thermal runaway of a LiCoO2 pouch cell, through its interrelated dynamic structural, thermal and electrical responses. Failure mechanisms across multiple length scales are explored using a post-mortem multi-scale tomography approach, revealing significant morphological and phase changes in the LiCoO2 electrode microstructure and location dependent degradation. This combined operando and multi-scale X-ray computed tomography (CT) technique is demonstrated as a comprehensive approach to understanding battery degradation and failure.

  12. Market research and forecast on the rotating anode target of X-ray tube used for CT%CT机X射线管用旋转阳极靶材市场研究与预测

    Institute of Scientific and Technical Information of China (English)

    高丽娜

    2012-01-01

    阐述了CT机X射线管用旋转阳极靶材的工作原理及其常见失效形式。随着CT机市场的日渐壮大。其对旋转阳极靶材的需求将越来越大。文中从3个方面全面阐明了国内CT机X射线管用旋转阳极靶材的市场需求及其产业现状。最后,提出了整合国内旋转阳极靶材行业现有的技术力量,引进专业技术人才,自主研发的建议,以期尽快实现高质量CT机X射线管旋转阳极靶材的国产化。%The paper elaborates the operating principle and common failure forms about rotating anode target of X-ray tube used for CT. The rotating anode target is an important part of X-ray tube, also need regular replacement of wearing parts. It directly effects the intensity of X-ray emitted by the X ray tube and the life of X ray tube. With the growing market of CT, the rotating anode target will be needed more and more. The paper elaborates the market demands and industry situation of rotating anode target of X-ray tube used for CT in China from three aspects. Finally, the author proposes some suggestions on achieving the localization of rotating anode target of X-ray tube used for CT with higher quality as soon as possible, by integrating existing techniques, introducing professional talents, independent research and developmen

  13. Spatial dispersion and clustering of soil structure through lacunarity of X-ray CT images of soil macropore volumes

    Science.gov (United States)

    San José Martínez, Fernando; Caniego, Javier; García-Gutiérrez, Carlos

    2016-04-01

    Lacunarity can be seen as a scale dependent measure of heterogeneity or texture ―in terms of image analysis― that was first introduced to quantify different patterns of dispersion and clustering that display geometrical objects with the same fractal dimension. Notwithstanding, lacunarity functions have been revealed as means to measure the deviation of object's geometrical structure from translational invariance beyond self-similarity and fractal geometry. In this work, we will explore how lacunarity quantifies different patterns of dispersion and clustering of different geometrical structures of soil macropore volumes imaged by X-ray computed tomography. Samples extracted from columns were collected at the experimental farm "Finca La Grajera" in La Rioja (Spain), property of La Rioja Regional Government (northern Spain). The vineyard selected was established in 1996. During the 1996 to 2004 period, the soil management was conventional tillage. Before the vineyard was established in 1996, a pasture-legume-cereal rotation was used. In 2004 an experiment was established with different types of soil cover management in between. On December 2010 columns were extracted vertically by percussion drilling between rows of the vineyard.

  14. Towards standardization of x-ray beam filters in digital mammography and digital breast tomosynthesis: Monte Carlo simulations and analytical modelling

    Science.gov (United States)

    Shrestha, Suman; Vedantham, Srinivasan; Karellas, Andrew

    2017-03-01

    In digital breast tomosynthesis and digital mammography, the x-ray beam filter material and thickness vary between systems. Replacing K-edge filters with Al was investigated with the intent to reduce exposure duration and to simplify system design. Tungsten target x-ray spectra were simulated with K-edge filters (50 µm Rh; 50 µm Ag) and Al filters of varying thickness. Monte Carlo simulations were conducted to quantify the x-ray scatter from various filters alone, scatter-to-primary ratio (SPR) with compressed breasts, and to determine the radiation dose to the breast. These data were used to analytically compute the signal-difference-to-noise ratio (SDNR) at unit (1 mGy) mean glandular dose (MGD) for W/Rh and W/Ag spectra. At SDNR matched between K-edge and Al filtered spectra, the reductions in exposure duration and MGD were quantified for three strategies: (i) fixed Al thickness and matched tube potential in kilovolts (kV); (ii) fixed Al thickness and varying the kV to match the half-value layer (HVL) between Al and K-edge filtered spectra; and, (iii) matched kV and varying the Al thickness to match the HVL between Al and K-edge filtered spectra. Monte Carlo simulations indicate that the SPR with and without the breast were not different between Al and K-edge filters. Modelling for fixed Al thickness (700 µm) and kV matched to K-edge filtered spectra, identical SDNR was achieved with 37–57% reduction in exposure duration and with 2–20% reduction in MGD, depending on breast thickness. Modelling for fixed Al thickness (700 µm) and HVL matched by increasing the kV over (0,4) range, identical SDNR was achieved with 62–65% decrease in exposure duration and with 2–24% reduction in MGD, depending on breast thickness. For kV and HVL matched to K-edge filtered spectra by varying Al filter thickness over (700, 880) µm range, identical SDNR was achieved with 23–56% reduction in exposure duration and 2–20% reduction in MGD, depending on breast thickness

  15. A sparsity-based iterative algorithm for reconstruction of micro-CT images from highly undersampled projection datasets obtained with a synchrotron X-ray source

    Science.gov (United States)

    Melli, S. Ali; Wahid, Khan A.; Babyn, Paul; Cooper, David M. L.; Gopi, Varun P.

    2016-12-01

    Synchrotron X-ray Micro Computed Tomography (Micro-CT) is an imaging technique which is increasingly used for non-invasive in vivo preclinical imaging. However, it often requires a large number of projections from many different angles to reconstruct high-quality images leading to significantly high radiation doses and long scan times. To utilize this imaging technique further for in vivo imaging, we need to design reconstruction algorithms that reduce the radiation dose and scan time without reduction of reconstructed image quality. This research is focused on using a combination of gradient-based Douglas-Rachford splitting and discrete wavelet packet shrinkage image denoising methods to design an algorithm for reconstruction of large-scale reduced-view synchrotron Micro-CT images with acceptable quality metrics. These quality metrics are computed by comparing the reconstructed images with a high-dose reference image reconstructed from 1800 equally spaced projections spanning 180°. Visual and quantitative-based performance assessment of a synthetic head phantom and a femoral cortical bone sample imaged in the biomedical imaging and therapy bending magnet beamline at the Canadian Light Source demonstrates that the proposed algorithm is superior to the existing reconstruction algorithms. Using the proposed reconstruction algorithm to reduce the number of projections in synchrotron Micro-CT is an effective way to reduce the overall radiation dose and scan time which improves in vivo imaging protocols.

  16. X-ray Examination of the Breast Quality Control Explore%乳腺X线检查的质量控制探究

    Institute of Scientific and Technical Information of China (English)

    张学勤; 汪秀玲; 刘洪

    2014-01-01

    Objective To evaluate the quality control of X-ray examination of the breast. Methods Summed up the work of the breast X-ray examination of the process, position, quality control. Result The photographic work of preparation, position selection, patient notes and post-image processing and other mat ers is essential to the quality of management control. Conclusion Establishing quality assurance standards, diagnosis and treatment of breast disease is the basic guarantee.%目的:探讨乳腺X线检查的质量控制。方法总结了作者工作中的乳腺X线检查的流程,体位,注意事项等质控事项。结果工作中的摄影准备,体位选择,患者注意事项及图像后处理等事项对乳腺X线的质量管理控制至关重要。结论建立乳腺质量保证标准,是乳腺疾病的诊治工作基本保证。

  17. 乳腺X线检查的质量控制探究%Quality Control of Breast X-ray Examination

    Institute of Scientific and Technical Information of China (English)

    张学勤; 汪秀玲; 刘洪

    2014-01-01

    Objective To evaluate the quality control of X-ray examination of the breast. Methods Summed up the work of the breast X-ray examination of the process, position, quality control.Results The photographic work of preparation, position selection, patient notes and post-image processing and other mat ers is essential to the quality of management control.Conclusion Establishing quality assurance standards, diagnosis and treatment of breast disease is the basic guarantee.%目的探讨乳腺X线检查的质量控制。方法总结了作者工作中的乳腺X线检查的流程,体位,注意事项等质控事项。结果工作中的摄影准备,体位选择,病人注意事项及图像后处理等事项对乳腺X线的质量管理控制至关重要。结论建立乳腺质量保证标准,是乳腺疾病的诊治工作基本保证。

  18. High density resolution synchrotron radiation based x-ray microtomography (SR μCT) for quantitative 3D-morphometrics in zoological sciences

    Science.gov (United States)

    Nickel, Michael; Hammel, Jörg U.; Herzen, Julia; Bullinger, Eric; Beckmann, Felix

    2008-08-01

    Zoological sciences widely rely on morphological data to reconstruct and understand body structures of animals. The best suitable methods like tomography allow for a direct representation of 3D-structures. In recent years, synchrotron radiation based x-ray microtomography (SR μCT) placed high resolutions to the disposal of morphologists. With the development of highly brilliant and collimated third generation synchrotron sources, phase contrast SR μCT became widely available. A number of scientific contributions stressed the superiority of phase contrast over absorption contrast. However, here we demonstrate the power of high density resolution methods based on absorption-contrast SRμCT for quantitative 3D-measurements of tissues and other delicate bio-structures in zoological sciences. We used beamline BW2 at DORIS III (DESY, Hamburg, Germany) to perform microtomography on tissue and mineral skeletons of marine sponges (Porifera) which were shock frozen and/or fixed in a glutamate osmium tetroxide solution, followed by critical point drying. High density resolution tomographic reconstructions allowed running quantitative 3D-image analyses in Matlab and ImageJ. By applying contrast and shape rule based algorithms we semi-automatically extracted and measured sponge body structures like mineral spicules, elements of the canal system or tissue structures. This lead to a better understanding of sponge biology: from skeleton functional morphology and internal water flow regimes to body contractility. Our high density resolution based quantitative approach can be applied to a wide variety of biological structures. However, two prerequisites apply: (1) maximum density resolution is necessary; (2) edge effects as seen for example in phase outline contrast SR μCT must not be present. As a consequence, to allow biological sciences to fully exploit the power of SR μCT further increase of density resolution in absorption contrast methods is desirable.

  19. Simulation of dark-field imaging of micro-calcifications in human breast tissue with X-ray Talbot-Lau interferometry

    Science.gov (United States)

    Ritter, A.; Anton, G.; Bayer, F.; Gödel, K.; Pelzer, G.; Rieger, J.; Weber, T.; Zang, A.; Michel, T.

    2014-05-01

    A simulation of dark-field imaging of sub-resolution structures with X-ray Talbot-Lau interferometry is presented. Data obtained from the simulation shows good agreement to a signal found in the dark-field image of a surgically removed sample of human breast tissue containing micro calcifications. A measure for the type of micro calcifications is introduced which can be calculated from dark-field signals. In a further analysis of the simulated data, it can be shown that the measure can be used to discriminate between different calcifications types.

  20. X-ray induced formation of γ-H2AX foci after full-field digital mammography and digital breast-tomosynthesis.

    Directory of Open Access Journals (Sweden)

    Siegfried A Schwab

    Full Text Available PURPOSE: To determine in-vivo formation of x-ray induced γ-H2AX foci in systemic blood lymphocytes of patients undergoing full-field digital mammography (FFDM and to estimate foci after FFDM and digital breast-tomosynthesis (DBT using a biological phantom model. MATERIALS AND METHODS: The study complies with the Declaration of Helsinki and was performed following approval by the ethic committee of the University of Erlangen-Nuremberg. Written informed consent was obtained from every patient. For in-vivo tests, systemic blood lymphocytes were obtained from 20 patients before and after FFDM. In order to compare in-vivo post-exposure with pre-exposure foci levels, the Wilcoxon matched pairs test was used. For in-vitro experiments, isolated blood lymphocytes from healthy volunteers were irradiated at skin and glandular level of a porcine breast using FFDM and DBT. Cells were stained against the phosphorylated histone variant γ-H2AX, and foci representing distinct DNA damages were quantified. RESULTS: Median in-vivo foci level/cell was 0.086 (range 0.067-0.116 before and 0.094 (0.076-0.126 after FFDM (p = 0.0004. In the in-vitro model, the median x-ray induced foci level/cell after FFDM was 0.120 (range 0.086-0.140 at skin level and 0.035 (range 0.030-0.050 at glandular level. After DBT, the median x-ray induced foci level/cell was 0.061 (range 0.040-0.081 at skin level and 0.015 (range 0.006-0.020 at glandular level. CONCLUSION: In patients, mammography induces a slight but significant increase of γ-H2AX foci in systemic blood lymphocytes. The introduced biological phantom model is suitable for the estimation of x-ray induced DNA damages in breast tissue in different breast imaging techniques.

  1. Testable uniqueness conditions for empirical assessment of undersampling levels in total variation-regularized X-ray CT

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Sauer; Kruschel, C.; Lorenz, D. A.

    2015-01-01

    We study recoverability in fan-beam computed tomography (CT) with sparsity and total variation priors: how many underdetermined linear measurements suffice for recovering images of given sparsity? Results from compressed sensing (CS) establish such conditions for example for random measurements...

  2. For delayed-type contusion of lung X-ray and CT diagnosis value analysis%对于迟发型肺挫伤X线与CT诊断的价值分析

    Institute of Scientific and Technical Information of China (English)

    王波

    2012-01-01

    目的评价X线与CT对迟发型肺挫伤的诊断价值。方法回顾性的分析确诊的肺挫伤的X线及CT资料,分析其动态变化,探讨X线、CT对迟发型肺挫伤的诊断价值。结论对于有胸部外伤患者,早期X线与CT影像表现阴性,而有临床不适症状的,动态观察X线与CT影像表现,对于迟发型肺挫伤的诊断能提供可靠信息,并能进一步观察疾病的转归情况。%objective: to evaluate the x ray and CT in diagnosis of late-onset pulmonary Methods: retrospective analysis of pulmonary contusion diagnosed the x ray and CT information, analyze its dynamics, exploring the x line, the diagnostic value of CT on delayed pulmonary contusion.contusion.Conclusions: for patients with chest trauma, early x ray and CT Imaging-negative and clinical symptoms of discomfort, x-ray and CT dynamic observation of imaging, for delayed diagnosis of pulmonary contusion can provide reliable information, and further observation on the prognosis of the disease.

  3. Search for novel contrast materials in dual-energy x-ray breast imaging using theoretical modeling of contrast-to-noise ratio.

    Science.gov (United States)

    Karunamuni, R; Maidment, A D A

    2014-08-01

    Contrast-enhanced (CE) dual-energy (DE) x-ray breast imaging uses a low- and high-energy x-ray spectral pair to eliminate soft-tissue signal variation and thereby increase the detectability of exogenous imaging agents. Currently, CEDE breast imaging is performed with iodinated contrast agents. These compounds are limited by several deficiencies, including rapid clearance and poor tumor targeting ability. The purpose of this work is to identify novel contrast materials whose contrast-to-noise ratio (CNR) is comparable or superior to that of iodine in the mammographic energy range. A monoenergetic DE subtraction framework was developed to calculate the DE signal intensity resulting from the logarithmic subtraction of the low- and high-energy signal intensities. A weighting factor is calculated to remove the dependence of the DE signal on the glandularity of the breast tissue. Using the DE signal intensity and weighting factor, the CNR for materials with atomic numbers (Z) ranging from 1 to 79 are computed for energy pairs between 10 and 50 keV. A group of materials with atomic numbers ranging from 42 to 63 were identified to exhibit the highest levels of CNR in the mammographic energy range. Several of these materials have been formulated as nanoparticles for various applications but none, apart from iodine, have been investigated as CEDE breast imaging agents. Within this group of materials, the necessary dose fraction to the LE image decreases as the atomic number increases. By reducing the dose to the LE image, the DE subtraction technique will not provide an anatomical image of sufficient quality to accompany the contrast information. Therefore, materials with Z from 42 to 52 provide nearly optimal values of CNR with energy pairs and dose fractions that provide good anatomical images. This work is intended to inspire further research into new materials for optimized CEDE breast functional imaging.

  4. First-order convex feasibility algorithms for iterative image reconstruction in limited angular-range X-ray CT

    CERN Document Server

    Sidky, Emil Y; Pan, Xiaochuan

    2012-01-01

    Iterative image reconstruction (IIR) algorithms in Computed Tomography (CT) are based on algorithms for solving a particular optimization problem. Design of the IIR algorithm, therefore, is aided by knowledge of the solution to the optimization problem on which it is based. Often times, however, it is impractical to achieve accurate solution to the optimization of interest, which complicates design of IIR algorithms. This issue is particularly acute for CT with a limited angular-range scan, which leads to poorly conditioned system matrices and difficult to solve optimization problems. In this article, we develop IIR algorithms which solve a certain type of optimization called convex feasibility. The convex feasibility approach can provide alternatives to unconstrained optimization approaches and at the same time allow for efficient algorithms for their solution -- thereby facilitating the IIR algorithm design process. An accelerated version of the Chambolle-Pock (CP) algorithm is adapted to various convex fea...

  5. Influence of different types of breast X-ray on diagnosis of breast cancer%乳腺 X线不同分型对乳腺癌诊断的影响

    Institute of Scientific and Technical Information of China (English)

    于书奎; 孙男男

    2014-01-01

    目的:分析乳腺X线不同分型对乳腺癌诊断的影像,提高诊断准确性。方法收集本院2010年6月~2013年6月乳腺癌患者共计160例,行模拟乳腺X线摄影系统+CR图像处理,并经手术病理证实为乳腺癌,对不同X线分型与漏诊的情况进行分析。结果乳腺不同X线分型对乳腺癌诊断有影响,检查160例中漏诊9例,3例为致密型,6例为腺纤维型。结论在X线诊断过程中,仔细阅片,注意方法,加强责任心,规范操作,可减少钼靶X线检查的漏诊。%Objective To analyze effect of different types of breast X-ray for breast cancer diagnosis to improve the diagnostic accuracy .Methods Collected 160 cases of breast cancer patients from June 2010 to June 2013 in our hospital to perform line simulation breast X-ray photography system +CR image processing , and diagnosis of breast cancer confirmed by surgery pathology , the situation of different classification and diag-nosis by X-ray analysis .Results different breast X-ray classification had influence on the breast cancer diag-nosis, out of 160 cases, 9 cases of misdiagnosis , 3 cases of dense type , 6 cases of gland fiber type .Conclusion In the process of X-ray diagnosis , reading carefully and paying attention to methods , strengthening the sense of responsibility , standardizing operation can reduce the molybdenum target X-ray in diagnosis .

  6. Comparative analysis of X-ray and spiral CT scan in spinal fractures%脊椎骨折X线平片与螺旋CT对比分析

    Institute of Scientific and Technical Information of China (English)

    刘悌; 李行胜

    2011-01-01

    Objective :To analyze the features of X-ray film and spiral CT scans in spinal fractures for assessment of the diagnostic value. Methods:The imaging data were retrospectively analyzed in 156 cases with vertebral fractures undergone X-ray examination and spiral CT scanning. Results:Of the total 156 cases of spinal fractures, cervical spine fracture was seen in 45, thoracic vertebral fracture in 22, fracture of lumbar vertebra fracture in 79, sacrococcygeal vertebrae fracture in 10, cervicothoracic fracture in 6 and thoracolumbar in 15. X-ray film exposed vertebral fracture in 152(97.44% ), accessory fractures in 35(22.44% ), bone chips in 31 ( 19.87% ), spondylolisthesis of small joints in 25 ( 16.03 ), spinal stenosis in 31 ( 19.87 % ), kyphotic angulation in 43 (27.56%) and vertebra translocation in 23 ( 14.74 ), and the corresponding results by CT scanning were 156 (100%), 53 (33. 97%),46 (29. 49%),40 (26.64%) ,40(26.64%),50(32.05%) and 42(26.92% ) ,respectively. Comparison by x2 test showed the difference between X-ray film and CT scans concerning fractures of vertebra body, bone chips and spinal stenosis and deformation( P > 0.05; P < 0. 05 ). Besides, CT could reveal burst fractures, spinal cord compression, hematoma and soft tissue changes. Conclusion: X-ray film can be primary approach to diagnosis of vertebral fractures, while spiral CT can keep from misdiagnosis due to its function of three dimensional and multiplanar reconstruction.%目的::分析脊椎骨折X线平片与螺旋CT表现,探讨它们对脊椎骨折的诊断价值.方法:回顾分析156例脊椎骨折的X线平片与螺旋CT影像学资料.结果:156例脊椎骨折中,颈椎骨折45例,胸椎骨折22例,腰椎骨折79例,骶尾椎10例;其中颈胸椎骨折6例,胸腰椎骨折15例.X线平片显示椎体骨折、附件骨折、骨碎片、小关节滑脱、椎管狭窄、脊柱后突成角及椎体移位检出率分别为97.44%(152例)、22.44%(35例)、19.87%(31

  7. Investigation of optimal parameters for penalized maximum-likelihood reconstruction applied to iodinated contrast-enhanced breast CT

    Science.gov (United States)

    Makeev, Andrey; Ikejimba, Lynda; Lo, Joseph Y.; Glick, Stephen J.

    2016-03-01

    Although digital mammography has reduced breast cancer mortality by approximately 30%, sensitivity and specificity are still far from perfect. In particular, the performance of mammography is especially limited for women with dense breast tissue. Two out of every three biopsies performed in the U.S. are unnecessary, thereby resulting in increased patient anxiety, pain, and possible complications. One promising tomographic breast imaging method that has recently been approved by the FDA is dedicated breast computed tomography (BCT). However, visualizing lesions with BCT can still be challenging for women with dense breast tissue due to the minimal contrast for lesions surrounded by fibroglandular tissue. In recent years there has been renewed interest in improving lesion conspicuity in x-ray breast imaging by administration of an iodinated contrast agent. Due to the fully 3-D imaging nature of BCT, as well as sub-optimal contrast enhancement while the breast is under compression with mammography and breast tomosynthesis, dedicated BCT of the uncompressed breast is likely to offer the best solution for injected contrast-enhanced x-ray breast imaging. It is well known that use of statistically-based iterative reconstruction in CT results in improved image quality at lower radiation dose. Here we investigate possible improvements in image reconstruction for BCT, by optimizing free regularization parameter in method of maximum likelihood and comparing its performance with clinical cone-beam filtered backprojection (FBP) algorithm.

  8. The performance of MRI in detecting subarticular bone erosion of sacroiliac joint in patients with spondyloarthropathy: A comparison with X-ray and CT

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Libin [Department of Radiology, China-Japan Friendship Hospital, Beijing (China); Huang, Zhenguo, E-mail: zhuang680911@163.com [Department of Radiology, China-Japan Friendship Hospital, Beijing (China); Zhang, Xuezhe [Department of Radiology, China-Japan Friendship Hospital, Beijing (China); Chan, Queenie [Philips Healthcare, Hong Kong (China); Xu, Yanyan [Department of Radiology, China-Japan Friendship Hospital, Beijing (China); Wang, Guochun [Department of Rheumatology, China-Japan Friendship Hospital, Beijing (China); Wang, Wu [Department of Radiology, China-Japan Friendship Hospital, Beijing (China)

    2014-11-15

    Highlights: • MRI 3D-WS-bSSFP sequence has high spatial resolution and short scanning time. • This is the first time this sequence was applied to detect bone erosion of SI joint. • Its performance was compared with other commonly used diagnostic methods. • Result shows that this sequence is better than X-ray and T1W in the detection of bone erosion. • This sequence can be considered an alternative to CT in showing erosion in SpA patients. - Abstract: Objective: To assess the sensitivity and specificity of detecting subarticular bone erosion of sacroiliac (SI) joint in patients with spondyloarthritis (SpA) using MRI three-dimensional water selective balanced steady-state free precession sequence (3D-WS-bSSFP) and T1-weighted (T1W) sequence. Materials and methods: Radiography, CT and MRI of SI joint from 43 SpA patients were retrospectively analyzed. MRI examination sequences include T1W, short tau inversion recovery (STIR) and 3D-WS-bSSFP. Two radiologists, blinded to clinical data, independently determined bone erosion at bilateral sacral and iliac sides of the SI joint on radiography, CT, T1W and 3D-WS-bSSFP respectively. X{sup 2} test was used to compare the sensitivity of detecting bone erosion among different diagnostic methods. Results: Of the 86 sacral and 86 iliac articular surfaces from the 43 cases, radiography, CT, MRI T1W and 3D-WS-bSSFP showed the presence of bone erosion in 40, 74, 50 and 71 articular surfaces respectively. CT and MRI 3D-WS-bSSFP demonstrated similar sensitivity (x{sup 2} = 0.11, P = 0.74), and both were superior to radiography (x{sup 2} = 15.17, P < 0.01 and x{sup 2} = 12.78, P < 0.01, respectively) and T1W (x{sup 2} = 7.26, P < 0.01 and x{sup 2} = 5.62, P < 0.05). Using CT diagnosis as the gold standard, the sensitivity and specificity of detecting bone erosion for MRI 3D-WS-bSSFP and T1W sequences were 91.8%, 96.9%, and 60.8%, 94.9% respectively. Conclusion: MRI 3D-WS-bSSFP sequence is associated with short scanning time

  9. Flow behaviour of supercritical CO2 and brine in Berea sandstone during drainage and imbibition revealed by medical X-ray CT images

    Science.gov (United States)

    Zhang, Yi; Nishizawa, Osamu; Kiyama, Tamotsu; Chiyonobu, Shun; Xue, Ziqiu

    2014-06-01

    We injected Berea sandstone with supercritical CO2 and imaged the results with a medical X-ray computed tomography (CT) scanner. The images were acquired by injecting CO2 into a core of brine-saturated sandstone (drainage), and additional images were acquired during reinjection of brine (imbibition) after drainage. We then analysed the temporal variations of CO2 saturation maps obtained from the CT images. The experiments were performed under a confining pressure of 12 MPa, a pore pressure of 10 MPa and a temperature of 40 °C. Porosity and CO2 saturation were calculated for each image voxel of the rock on the basis of the Hounsfield unit values (CT numbers) measured at three states of saturation: dry, full brine saturation and full CO2 saturation. The saturation maps indicated that the distributions of CO2 and brine were controlled by the sub-core-scale heterogeneities which consisted of a laminated structure (bedding) with high- and low-porosity layers. During drainage, CO2 preferentially flowed through the high-porosity layers where most of the CO2 was entrapped during low flow-rate imbibition. The entrapped CO2 was flushed out when high flow-rate imbibition commenced. Plots of the voxel's CT number against porosity revealed the relationship between fluid replacement and porosity. By reference to the CT numbers at the full brine-saturated stage, differential CT numbers were classified into three bins corresponding to voxel porosity: high, medium and low porosity. Distributions of the differential CT number for the three porosity bins were bimodal and in order with respect to the porosity bins during both drainage and imbibitions; however, the order differed between the two stages. This difference suggested that different replacement mechanisms operated for the two processes. Spatial autocorrelation of CO2 saturation maps on sections perpendicular to the flow direction revealed remarkable changes during passage of the replacement fronts during both drainage and

  10. 婴幼儿先天性膈疝的X线及CT表现%X-ray and CT features of congenital diaphragmatic hernia in infant

    Institute of Scientific and Technical Information of China (English)

    代燕增; 周朝理

    2012-01-01

    目的 探讨先天性膈疝的影像学诊断价值.方法 回顾性分析13例经X线胸部平片、钡餐或钡灌肠造影及CT检查而诊断为先天性膈疝,其中8例经手术证实.结果 胸腹膜裂孔疝X线胸腹部平片表现为患侧胸腔内见含气肠襻,钡餐或钡灌肠造影显示小肠或结肠疝入胸腔内;食管裂孔疝X线胸腹部平片表现为心膈角处透亮影或无异常,钡餐显示胃疝入胸腔内或见三环征;胸骨后疝X线胸腹部平片表现为心膈角处见含气或无气肿块影,钡餐显示胃及小肠位置及形态正常,钡灌肠造影显示结肠疝入胸骨后方心膈角处.而CT二维重建成像均可显示膈肌缺损的大小、部位及疝入胸腔内的脏器形态.胸腹膜裂孔疝6例,食管裂孔疝5例,胸骨后疝2例,其中位于左侧10例,右侧3例.结论 联合合理运用影像学检查对婴幼儿先天性膈疝具有很高的诊断价值,为临床手术治疗提供重要的依据.%Objective To investigate imaging value in diagnosing congenital diaphragmatic hernia in infants. Methods 13 cases with congenital diaphragmatic hernia confirmed by X-ray, barium meal or barium enema examination and CT examination were ana-lysed retrospectively. In which 8 cases were confirmed by operation. Results The pleuroperitoneal hernia,X-ray showed gas intesti-nal loops at disordered ipsilateral chest, barium meal or barium enema examination showed the small intestine or colon herniated into the chest cavity; the esophageal hiatal hernia, X-ray showed cardiac septal corner translucent shadow or without abnormal, barium meal showed the stomach herniated into the chest cavity, or the three-ring sign; the morgagni hernia,X-ray showed masses at the cardiac septal corner with gas or without gas inside the masses, barium meal showed the location and morphology of the stomach and small intestine to be normal, barium enema examination showed colon herniated into the chest behind the heart and diaphragm cor

  11. Detection of metastases in breast cancer patients. Comparison of FDG PET with chest X-ray, bone scintigraphy and ultrasound of the abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Dose-Schwarz, J.; Mahner, S.; Schirrmacher, S.; Mueller, V. [Klinik und Poliklinik fuer Gynaekologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Jenicke, L.; Brenner, W. [Klinik fuer Nuklearmedizin, Universitaetsklinikum Hamburg-Eppendorf (Germany); Habermann, C.R. [Klinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany)

    2008-07-01

    Distant metastases at primary diagnosis are a prognostic key factor in breast cancer patients and play a central role in therapeutic decisions. To detect them, chest X-ray, abdominal ultrasound, and bone scintigraphy are performed as standard of care in Germany and many centers worldwide. Although FDG PET detects metastatic disease with high accuracy, its diagnostic value in breast cancer still needs to be defined. The aim of this study was to compare the diagnostic performance of FDG PET with conventional imaging. Patients, methods: a retrospective analysis of 119 breast cancer patients who presented for staging was performed. Whole-body FDG-PET (n = 119) was compared with chest X-ray (n = 106) and bone scintigraphy (n = 95). Each imaging modality was independently assessed and classified for metastasis (negative, equivocal and positive). The results of abdominal ultrasound (n = 100) were classified as negative and positive according to written reports. Imaging results were compared with clinical follow-up including follow-up imaging procedures and histopathology. Results: FDG-PET detected distant metastases with a sensitivity of 87.3% and a specificity of 83.3%. In contrast, the sensitivity and specificity of combined conventional imaging procedures was 43.1% and 98.5%, respectively. Regarding so-called equivocal and positive results as positive, the sensitivity and specificity of FDG-PET was 93.1% and 76.6%, respectively, compared to 61.2% and 86.6% for conventional imaging. Regarding different locations of metastases the sensitivity of FDG PET was superior in the detection of pulmonary metastases and lymph node metastases of the mediastinum in comparison to chest X-ray, whereas the sensitivity of FDG PET in the detection of bone and liver metastases was comparable with bone scintigraphy and ultrasound of the abdomen. Conclusions: FDG-PET is more sensitive than conventional imaging procedures for detection of distant breast cancer metastases and should be

  12. Performance of ultralow-dose CT with iterative reconstruction in lung cancer screening: limiting radiation exposure to the equivalent of conventional chest X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Adrian [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); University Hospital Pitie-Salpetriere, Department of Polyvalent and Oncological Radiology, Paris (France); Landau, Julia; Buetikofer, Yanik; Leidolt, Lars; Brela, Barbara; May, Michelle; Heverhagen, Johannes; Christe, Andreas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Ebner, Lukas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Duke University Medical Center, Department of Radiology, Durham, NC (United States)

    2016-10-15

    To investigate the detection rate of pulmonary nodules in ultralow-dose CT acquisitions. In this lung phantom study, 232 nodules (115 solid, 117 ground-glass) of different sizes were randomly distributed in a lung phantom in 60 different arrangements. Every arrangement was acquired once with standard radiation dose (100 kVp, 100 references mAs) and once with ultralow radiation dose (80 kVp, 6 mAs). Iterative reconstruction was used with optimized kernels: I30 for ultralow-dose, I70 for standard dose and I50 for CAD. Six radiologists examined the axial 1-mm stack for solid and ground-glass nodules. During a second and third step, three radiologists used maximum intensity projection (MIPs), finally checking with computer-assisted detection (CAD), while the others first used CAD, finally checking with the MIPs. The detection rate was 95.5 % with standard dose (DLP 126 mGy*cm) and 93.3 % with ultralow-dose (DLP: 9 mGy*cm). The additional use of either MIP reconstructions or CAD software could compensate for this difference. A combination of both MIP reconstructions and CAD software resulted in a maximum detection rate of 97.5 % with ultralow-dose. Lung cancer screening with ultralow-dose CT using the same radiation dose as a conventional chest X-ray is feasible. (orig.)

  13. Study of capillary absorption kinetics by X-ray CT imaging techniques: a survey on sedimentary rocks of Sicily

    Directory of Open Access Journals (Sweden)

    Tiziano Schillaci

    2008-04-01

    Full Text Available Sedimentary rocks are natural porous materials with a great percent of microscopic interconnected pores: they contain fluids, permitting their movement on macroscopic scale. Generally, these rocks present porosity higher then metamorphic rocks. Under certain points of view, this feature represents an advantage; on the other hand, this can constitute an obstacle for cultural heritage applications, because the porosity grade can lead to a deterioration of the lapideous monument for water capillary absorption. In this paper, CT (Computerized Tomography image techniques are applied to capillary absorption kinetics in sedimentary rocks utilized for the Greek temples as well as baroc monuments, respectively located in western and southeastern Sicily. Rocks were sampled near the archaeological areas of Agrigento, Segesta, Selinunte and Val di Noto. CT images were acquired at different times, before and after the water contact, using image elaboration techniques during the acquisition as well as the post-processing phases. Water distribution into porous spaces has been evaluated on the basis of the Hounsfield number, estimated for the 3-D voxel structure of samples. For most of the considered samples, assumptions based on Handy model permit to correlate the average height of the wetting front to the square root of time. Stochastic equations were introduced in order to describe the percolative water behavior in heterogeneous samples, as the Agrigento one. Before the CT acquisition, an estimate of the capillary absorption kinetics has been carried out by the gravimetric method. A petrographical characterization of samples has been performed by stereomicroscope observations, while porosity and morphology of porous have been surveyed by SEM (Scanning Electron Microscope images. Furthermore, the proposed methods have also permitted to define penetration depth as well as distribution uniformity of materials used for restoration and conservation of historical

  14. Simultaneous Reduction in Noise and Cross-Contamination Artifacts for Dual-Energy X-Ray CT

    Directory of Open Access Journals (Sweden)

    Baojun Li

    2013-01-01

    Full Text Available Purpose. Dual-energy CT imaging tends to suffer from much lower signal-to-noise ratio than single-energy CT. In this paper, we propose an improved anticorrelated noise reduction (ACNR method without causing cross-contamination artifacts. Methods. The proposed algorithm diffuses both basis material density images (e.g., water and iodine at the same time using a novel correlated diffusion algorithm. The algorithm has been compared to the original ACNR algorithm in a contrast-enhanced, IRB-approved patient study. Material density accuracy and noise reduction are quantitatively evaluated by the percent density error and the percent noise reduction. Results. Both algorithms have significantly reduced the noises of basis material density images in all cases. The average percent noise reduction is 69.3% and 66.5% with the ACNR algorithm and the proposed algorithm, respectively. However, the ACNR algorithm alters the original material density by an average of 13% (or 2.18 mg/cc with a maximum of 58.7% (or 8.97 mg/cc in this study. This is evident in the water density images as massive cross-contaminations are seen in all five clinical cases. On the contrary, the proposed algorithm only changes the mean density by 2.4% (or 0.69 mg/cc with a maximum of 7.6% (or 1.31 mg/cc. The cross-contamination artifacts are significantly minimized or absent with the proposed algorithm. Conclusion. The proposed algorithm can significantly reduce image noise present in basis material density images from dual-energy CT imaging, with minimized cross-contaminations compared to the ACNR algorithm.

  15. 4D imaging and quantification of pore structure modifications inside natural building stones by means of high resolution X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Dewanckele, J., E-mail: jan.dewanckele@ugent.be [Department of Geology and Soil Science - UGCT, Ghent University, Krijgslaan 281 S8, B-9000, Ghent (Belgium); De Kock, T.; Boone, M.A.; Cnudde, V. [Department of Geology and Soil Science - UGCT, Ghent University, Krijgslaan 281 S8, B-9000, Ghent (Belgium); Brabant, L.; Boone, M.N. [Department of Physics and Astronomy - UGCT, Ghent University, Proeftuinstraat 86, B-9000 Ghent (Belgium); Fronteau, G. [University of Reims Champagne-Ardenne (URCA), GEGENAA, EA3795, Reims (France); Van Hoorebeke, L. [Department of Physics and Astronomy - UGCT, Ghent University, Proeftuinstraat 86, B-9000 Ghent (Belgium); Jacobs, P. [Department of Geology and Soil Science - UGCT, Ghent University, Krijgslaan 281 S8, B-9000, Ghent (Belgium)

    2012-02-01

    Weathering processes have been studied in detail for many natural building stones. The most commonly used analytical techniques in these studies are thin-section petrography, SEM, XRD and XRF. Most of these techniques are valuable for chemical and mineralogical analysis of the weathering patterns. However, to obtain crucial quantitative information on structural evolutions like porosity changes and growth of weathering crusts in function of time, non-destructive techniques become necessary. In this study, a Belgian historical calcareous sandstone, the Lede stone, was exposed to gaseous SO{sub 2} under wet surface conditions according to the European Standard NBN EN 13919 (2003). Before, during and after the strong acid test, high resolution X-ray tomography has been performed to visualize gypsum crust formation to yield a better insight into the effects of gaseous SO{sub 2} on the pore modification in 3D. The tomographic scans were taken at the Centre for X-ray Tomography at Ghent University (UGCT). With the aid of image analysis, partial porosity changes were calculated in different stadia of the process. Increasing porosity has been observed visually and quantitatively below the new superficial formed layer of gypsum crystals. In some cases micro-cracks and dissolution zones were detected on the grain boundaries of quartz. By using Morpho+, an in-house developed image analysis program, radial porosity, partial porosity, ratio of open and closed porosity and equivalent diameter of individual pore structures have been calculated. The results obtained in this study are promising for a better understanding of gypsum weathering mechanisms, porosity changes and patterns on natural building stones in four dimensions. - Highlights: Black-Right-Pointing-Pointer We examine structural 3D differences inside building stones as a function of time. Black-Right-Pointing-Pointer Gypsum crust formation is quantified with X-ray CT in combination with image analysis. Black

  16. X-ray microfluorescence as a tool to analyze elemental changes in femur head induced by chemotherapy drugs for the treatment of breast cancer

    Science.gov (United States)

    Pickler, A.; Mota, C. L.; Mantuano, A.; Salata, C.; Nogueira, L. P.; Almeida, A. P.; Alessio, R.; Sena, G.; Braz, D.; de Almeida, C. E. V.; Barroso, R. C.

    2015-11-01

    Recently some developments in a large number of investigative techniques have been made with the objective to obtain a micrometer spatial resolution imaging of elemental concentrations. The X-ray microfluorescence analysis (μXRF) is one of those techniques which is based on the localized excitation of a small area on the surface of sample, providing information of all elements contained in the material under study. Breast cancer is the most common malignancy in Brazilian women. The main treatment strategies for the breast cancer are surgery and chemotherapy. As bone loss is one of the possible chemotherapy side effects, in this work was used μXRF technique on femoral head samples of female Wistar rats to evaluate Ca, Fe and Zn concentrations in order to investigate possible elemental changes in bone caused by the chemotherapy. Fifteen female rats were divided randomly in groups (five rats each). G1 group received doses of doxorubicin/cyclophosphamide drugs and G2 group was treated with docetaxel/cyclophosphamide drugs. μXRF measurements were carried out at the X-ray XRF beamline in the Brazilian Synchrotron Light Laboratory. The results showed significant decrease especially in Ca concentrations when comparing the treated groups with the control group.

  17. Experimental validation of a Monte Carlo-based kV x-ray projection model for the Varian linac-mounted cone-beam CT imaging system

    Science.gov (United States)

    Lazos, Dimitrios; Pokhrel, Damodar; Su, Zhong; Lu, Jun; Williamson, Jeffrey F.

    2008-03-01

    Fast and accurate modeling of cone-beam CT (CBCT) x-ray projection data can improve CBCT image quality either by linearizing projection data for each patient prior to image reconstruction (thereby mitigating detector blur/lag, spectral hardening, and scatter artifacts) or indirectly by supporting rigorous comparative simulation studies of competing image reconstruction and processing algorithms. In this study, we compare Monte Carlo-computed x-ray projections with projections experimentally acquired from our Varian Trilogy CBCT imaging system for phantoms of known design. Our recently developed Monte Carlo photon-transport code, PTRAN, was used to compute primary and scatter projections for cylindrical phantom of known diameter (NA model 76-410) with and without bow-tie filter and antiscatter grid for both full- and half-fan geometries. These simulations were based upon measured 120 kVp spectra, beam profiles, and flat-panel detector (4030CB) point-spread function. Compound Poisson- process noise was simulated based upon measured beam output. Computed projections were compared to flat- and dark-field corrected 4030CB images where scatter profiles were estimated by subtracting narrow axial-from full axial width 4030CB profiles. In agreement with the literature, the difference between simulated and measured projection data is of the order of 6-8%. The measurement of the scatter profiles is affected by the long tails of the detector PSF. Higher accuracy can be achieved mainly by improving the beam modeling and correcting the non linearities induced by the detector PSF.

  18. X 线与 CT 诊断对成软骨细胞瘤的诊断价值分析%Diagnostic value of X-ray and CT in diagnosis of chondroblastoma

    Institute of Scientific and Technical Information of China (English)

    税永平

    2013-01-01

    Objective X-ray and CT diagnostic value of chondroblastoma were discussed, and improve the imaging diagnostic level . Methods in January 2009-2013 in our hospital between January by X-ray or CT diagnosis of 62 cases of chondroblastoma patients were randomly divided into X-ray plain film in the diagnosis of group (group A) and the CT group (group B), each group of 31 cases, ultimately, all cases of surgical treatment and confirmed by pathology. Results A group of 31 patients, preoperative diagnosis of chondroblastoma 18 cases, 8 cases diagnosed as giant cell tumors of bone, cartilage myxoid fibroma, 4 cases were diagnosed as tumor, 1 case was diagnosed as bone X-ray diagnosis accuracy rate 58%, the misdiagnosis rate was 42% in group B, 31 patients, preoperative diagnosis of chondroblastoma 25 cases, 3 cases were diagnosed as aneurysm bone cyst, 2 cases were diagnosed as giant cell tumors of bone, 1 case was misdiagnosed as fibrosarcoma, CT diagnostic accuracy of 80%, the misdiagnosis rate 20% X-ray showed lesions were round or irregular limitations of bone destruction area, CT showed lesions with different degree of lobulated, border and clear, half annular calcification. Conclusion due to the density resolution higher than X-ray plain film, CT can discern subtle bone destruction, and can be found that damage zone calcifications, and to destroy the organization composition CT value in the measurement, so the diagnostic accuracy of chondroblastoma is significantly higher than X-ray plain film, worthy of clinical popularization and application.%目的:对 X 线与 CT 诊断成软骨细胞瘤的价值进行探讨,提高对本病影像诊断水平。方法将2009年1月至2013年1月间在我院经 X 线或 CT 诊断的62例成软骨细胞瘤患者随机分为 X 线平片诊断组(A 组)和经 CT 诊断组(B 组),每组各31例,所有病例最终均行手术治疗并经病理证实。结果 A 组31例患者,术前诊断为成软骨细胞瘤18例,8

  19. TU-CD-207-11: Patient-Driven Automatic Exposure Control for Dedicated Breast CT

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, A; Gazi, P [Biomedical Engineering Graduate Group, University of California Davis, Davis, CA (United States); Department of Radiology, UC Davis Medical Center, Sacramento, CA (United States); Seibert, J; Boone, J [Department of Radiology, UC Davis Medical Center, Sacramento, CA (United States); Department of Biomedical Engineering, University of California Davis, Davis, CA (United States)

    2015-06-15

    Purpose: To implement automatic exposure control (AEC) in dedicated breast CT (bCT) on a patient-specific basis using only the pre-scan scout views. Methods: Using a large cohort (N=153) of bCT data sets, the breast effective diameter (D) and width in orthogonal planes (Wa,Wb) were calculated from the reconstructed bCT image and pre-scan scout views, respectively. D, Wa, and Wb were measured at the breast center-of-mass (COM), making use of the known geometry of our bCT system. These data were then fit to a second-order polynomial “D=F(Wa,Wb)” in a least squares sense in order to provide a functional form for determining the breast diameter. The coefficient of determination (R{sup 2}) and mean percent error between the measured breast diameter and fit breast diameter were used to evaluate the overall robustness of the polynomial fit. Lastly, previously-reported bCT technique factors derived from Monte Carlo simulations were used to determine the tube current required for each breast diameter in order to match two-view mammographic dose levels. Results: F(Wa,Wb) provided fitted breast diameters in agreement with the measured breast diameters resulting in R{sup 2} values ranging from 0.908 to 0.929 and mean percent errors ranging from 3.2% to 3.7%. For all 153 bCT data sets used in this study, the fitted breast diameters ranged from 7.9 cm to 15.7 cm corresponding to tube current values ranging from 0.6 mA to 4.9 mA in order to deliver the same dose as two-view mammography in a 50% glandular breast with a 80 kV x-ray beam and 16.6 second scan time. Conclusion: The present work provides a robust framework for AEC in dedicated bCT using only the width measurements derived from the two orthogonal pre-scan scout views. Future work will investigate how these automatically chosen exposure levels affect the quality of the reconstructed image.

  20. Magnetic resonance (MR) imaging of prostatic tumours, a comparison with X-ray CT and transrectal sonography (TRS)

    Energy Technology Data Exchange (ETDEWEB)

    Bockisch, A.; Biersack, H.J.; Huenermann, B.; Schmitz, H.G.; Knopp, R.; Winkler, C.; Jaeger, N.; Vahlensieck, W.; Christ, F.

    1988-02-01

    A total of 7 healthy volunteers and 31 patients have been examined clinically, by MRI, TRS, and biopsy. In those patients with established carcinoma, a CT examination was also performed. For the MRI study, a superconducting MR 2000 imager (Picker International) operated at 0.15 T was used with multiplanar SE and IR sequnces. SE sequences with long echo times detected prostatitis, adenoma and carcinoma of the prostate with a high degree of sensitivity. However, at present, differentiation between adenoma, prostatis and carcinoma is not possible with sufficient accuracy. In these studies we were unable to establish a correlation between the signal pattern and staging and/or grading of the carcinoma. Reliable diagnosis of a prostate carcinoma still requires a biopsy. Because of the high soft tissue contrast and the possibility of selecting any orientation for the plane under investigation, however, MRI represents an improvement in the preoperative diagnosis of local spread.

  1. WE-G-207-02: Full Sequential Projection Onto Convex Sets (FS-POCS) for X-Ray CT Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Liu, L; Han, Y [Tianjin University, Tianjin (China); Jin, M [University of Texas at Arlington, Arlington, TX (United States)

    2015-06-15

    Purpose: To develop an iterative reconstruction method for X-ray CT, in which the reconstruction can quickly converge to the desired solution with much reduced projection views. Methods: The reconstruction is formulated as a convex feasibility problem, i.e. the solution is an intersection of three convex sets: 1) data fidelity (DF) set – the L2 norm of the difference of observed projections and those from the reconstructed image is no greater than an error bound; 2) non-negativity of image voxels (NN) set; and 3) piecewise constant (PC) set - the total variation (TV) of the reconstructed image is no greater than an upper bound. The solution can be found by applying projection onto convex sets (POCS) sequentially for these three convex sets. Specifically, the algebraic reconstruction technique and setting negative voxels as zero are used for projection onto the DF and NN sets, respectively, while the projection onto the PC set is achieved by solving a standard Rudin, Osher, and Fatemi (ROF) model. The proposed method is named as full sequential POCS (FS-POCS), which is tested using the Shepp-Logan phantom and the Catphan600 phantom and compared with two similar algorithms, TV-POCS and CP-TV. Results: Using the Shepp-Logan phantom, the root mean square error (RMSE) of reconstructed images changing along with the number of iterations is used as the convergence measurement. In general, FS- POCS converges faster than TV-POCS and CP-TV, especially with fewer projection views. FS-POCS can also achieve accurate reconstruction of cone-beam CT of the Catphan600 phantom using only 54 views, comparable to that of FDK using 364 views. Conclusion: We developed an efficient iterative reconstruction for sparse-view CT using full sequential POCS. The simulation and physical phantom data demonstrated the computational efficiency and effectiveness of FS-POCS.

  2. Abdominal x-ray

    Science.gov (United States)

    ... are, or may be, pregnant. Alternative Names Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also ...

  3. Extremity x-ray

    Science.gov (United States)

    ... degenerative) Bone tumor Broken bone (fracture) Dislocated bone Osteomyelitis (infection) Arthritis Other conditions for which the test ... Bone tumor Bone x-ray Broken bone Clubfoot Osteomyelitis X-ray Review Date 7/3/2016 Updated ...

  4. The Clinical Value of Molybdenum X-ray in Breast Cancer Diagnosis%钼钯X线在乳腺癌中的临床应用价值

    Institute of Scientific and Technical Information of China (English)

    吴焱

    2014-01-01

    目的:探讨钼钯x线对乳腺癌的诊断价值。方法:收集我院2010年1月至2013年2月间病例资料完整28例乳腺癌病例,所有病例均经手术病理证实,回顾性分析其x线表现,包括直接征象、间接征象。结果:28例乳腺癌中,左乳15例,右乳13例,部位以外上象限最多见,有17例;浸润性导管癌25例,混合癌1例,富于糖原透明细胞癌1例,原位癌1例;x线表现:肿块23例,微小钙化14例,局限性密度增高4例,结构紊乱2例,钙化伴星芒征2例,腺体结构紊乱伴异常血管影2例,乳头回缩、漏斗征2例,局部皮肤凹陷2例;局限性皮肤增厚2例;血管增粗1例,乳腺内淋巴结或腋前淋巴结肿大5例,结论:钼钯x线在乳腺癌的临床诊断与鉴别诊断中具有重要的价值,是诊断乳腺癌的首选影像学方法。%This paper aims at investigating the value of molybdenum X-ray in the diagnosis of breast cancer. The author col ected 28 breast cancer cases from January 2010 to February 2013, al of which have been confirmed both by surgery and pathology, and conducted retrospective analysis of the X-ray expression of these cases, including the direct and indirect signs. The result shows that, among the 28 breast cancer cases, there are 15 cases of breast cancer and 13 cases of right breast cancer. The parts of most of the patients are in upper quadrant and the parts of 17 cases are there; 25 cases of infiltrative ductal carcinoma,1case of mixed type carcinoma, 1 case of glycogen-rich, clear cellcarcinoma,1 case of carcinoma in situ; The X-ray findings include: mass(n=23),micro calcification(n=14), and limited density increase(n=4),2 cases of structural disorder, 2 cases of calcification with asterism,2 cases of gland disorder with abnormal blood vessel film, inverted nipple and hopper symptom (n=2), 2 cases of local skin pitting; limited pachyderma symptom(n=2), vascular increase(n=1), 5 cases of mammary

  5. Material identification in x-ray microscopy and micro CT using multi-layer, multi-color scintillation detectors.

    Science.gov (United States)

    Modgil, Dimple; Rigie, David S; Wang, Yuxin; Xiao, Xianghui; Vargas, Phillip A; La Rivière, Patrick J

    2015-10-21

    We demonstrate that a dual-layer, dual-color scintillator construct for microscopic CT, originally proposed to increase sensitivity in synchrotron imaging, can also be used to perform material quantification and classification when coupled with polychromatic illumination. We consider two different approaches to data handling: (1) a data-domain material decomposition whose estimation performance can be characterized by the Cramer-Rao lower bound formalism but which requires careful calibration and (2) an image-domain material classification approach that is more robust to calibration errors. The data-domain analysis indicates that useful levels of SNR (>5) could be achieved in one second or less at typical bending magnet fluxes for relatively large amounts of contrast (several mm path length, such as in a fluid flow experiment) and at typical undulator fluxes for small amount of contrast (tens of microns path length, such as an angiography experiment). The tools introduced could of course be used to study and optimize parameters for a wider range of potential applications. The image domain approach was analyzed in terms of its ability to distinguish different elemental stains by characterizing the angle between the lines traced out in a two-dimensional space of effective attenuation coefficient in the front and back layer images. This approach was implemented at a synchrotron and the results were consistent with simulation predictions.

  6. Monte Carlo simulation of glandular dose in a dedicated breast CT system

    Institute of Scientific and Technical Information of China (English)

    TANG Xiao; WEI Long; ZHAO Wei; WANG Yan-Fang; SHU Hang; SUN Cui-Li; WEI Cun-Feng; CAO Da-Quan; QUE Jie-Min; SHI Rong-Jian

    2012-01-01

    A dedicated breast CT system (DBCT) is a new method for breast cancer detection proposed in recent years.In this paper,the glandular dose in the DBCT is simulated using the Monte Carlo method.The phantom shape is half ellipsoid,and a series of phantoms with different sizes,shapes and compositions were constructed. In order to optimize the spectra,monoenergy X-ray beams of 5-80 keV were used in simulation.The dose distribution of a breast phantom was studied:a higher energy beam generated more uniform distribution,and the outer parts got more dose than the inner parts.For polyenergtic spectra,four spectra of Al filters with different thicknesses were simulated,and the polyenergtic glandular dose was calculated as a spectral weighted combination of the monoenergetic dose.

  7. Amorphous In–Ga–Zn–O thin-film transistor active pixel sensor x-ray imager for digital breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chumin; Kanicki, Jerzy, E-mail: kanicki@eecs.umich.edu [Solid-State Electronic Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-09-15

    Purpose: The breast cancer detection rate for digital breast tomosynthesis (DBT) is limited by the x-ray image quality. The limiting Nyquist frequency for current DBT systems is around 5 lp/mm, while the fine image details contained in the high spatial frequency region (>5 lp/mm) are lost. Also today the tomosynthesis patient dose is high (0.67–3.52 mGy). To address current issues, in this paper, for the first time, a high-resolution low-dose organic photodetector/amorphous In–Ga–Zn–O thin-film transistor (a-IGZO TFT) active pixel sensor (APS) x-ray imager is proposed for next generation DBT systems. Methods: The indirect x-ray detector is based on a combination of a novel low-cost organic photodiode (OPD) and a cesium iodide-based (CsI:Tl) scintillator. The proposed APS x-ray imager overcomes the difficulty of weak signal detection, when small pixel size and low exposure conditions are used, by an on-pixel signal amplification with a significant charge gain. The electrical performance of a-IGZO TFT APS pixel circuit is investigated by SPICE simulation using modified Rensselaer Polytechnic Institute amorphous silicon (a-Si:H) TFT model. Finally, the noise, detective quantum efficiency (DQE), and resolvability of the complete system are modeled using the cascaded system formalism. Results: The result demonstrates that a large charge gain of 31–122 is achieved for the proposed high-mobility (5–20 cm{sup 2}/V s) amorphous metal-oxide TFT APS. The charge gain is sufficient to eliminate the TFT thermal noise, flicker noise as well as the external readout circuit noise. Moreover, the low TFT (<10{sup −13} A) and OPD (<10{sup −8} A/cm{sup 2}) leakage currents can further reduce the APS noise. Cascaded system analysis shows that the proposed APS imager with a 75 μm pixel pitch can effectively resolve the Nyquist frequency of 6.67 lp/mm, which can be further improved to ∼10 lp/mm if the pixel pitch is reduced to 50 μm. Moreover, the

  8. Modeling shift-variant X-ray focal spot blur for high-resolution flat-panel cone-beam CT

    CERN Document Server

    Tilley, Steven; Siewerdsen, Jeffrey H; Stayman, J Webster

    2016-01-01

    Flat-panel cone-beam CT (CBCT) has been applied clinically in a number of high-resolution applications. Increasing geometric magnification can potentially improve resolution, but also increases blur due to an extended x-ray focal-spot. We present a shift-variant focal-spot blur model and incorporate it into a model-based iterative-reconstruction algorithm. We apply this algorithm to simulation and CBCT test-bench data. In a trabecular bone simulation study, we find traditional reconstruction approaches without a blur model exhibit shift-variant resolution properties that depend greatly on the acquisition protocol (e.g. short vs. full scans) and the anode angles of the rays used to reconstruct a particular region. For physical CBCT experiments focal spot blur was characterized and a spatial resolution phantom was scanned and reconstructed. In both experiments image quality using the shift-variant model was significantly improved over approaches that modeled no blur or only a shift-invariant blur, suggesting a ...

  9. X-Ray Supernovae

    CERN Document Server

    Immler, S; Immler, Stefan; Lewin, Walter H.G.

    2002-01-01

    We present a review of X-ray observations of supernovae (SNe). By observing the (~0.1--100 keV) X-ray emission from young SNe, physical key parameters such as the circumstellar matter (CSM) density, mass-loss rate of the progenitor and temperature of the outgoing and reverse shock can be derived as a function of time. Despite intensive search over the last ~25 years, only 15 SNe have been detected in X-rays. We review the individual X-ray observations of these SNe and discuss their implications as to our understanding of the physical processes giving rise to the X-ray emission.

  10. Effects of X-Ray Dose On Rhizosphere Studies Using X-Ray Computed Tomography.

    Directory of Open Access Journals (Sweden)

    Susan Zappala

    Full Text Available X-ray Computed Tomography (CT is a non-destructive imaging technique originally designed for diagnostic medicine, which was adopted for rhizosphere and soil science applications in the early 1980s. X-ray CT enables researchers to simultaneously visualise and quantify the heterogeneous soil matrix of mineral grains, organic matter, air-filled pores and water-filled pores. Additionally, X-ray CT allows visualisation of plant roots in situ without the need for traditional invasive methods such as root washing. However, one routinely unreported aspect of X-ray CT is the potential effect of X-ray dose on the soil-borne microorganisms and plants in rhizosphere investigations. Here we aimed to i highlight the need for more consistent reporting of X-ray CT parameters for dose to sample, ii to provide an overview of previously reported impacts of X-rays on soil microorganisms and plant roots and iii present new data investigating the response of plant roots and microbial communities to X-ray exposure. Fewer than 5% of the 126 publications included in the literature review contained sufficient information to calculate dose and only 2.4% of the publications explicitly state an estimate of dose received by each sample. We conducted a study involving rice roots growing in soil, observing no significant difference between the numbers of root tips, root volume and total root length in scanned versus unscanned samples. In parallel, a soil microbe experiment scanning samples over a total of 24 weeks observed no significant difference between the scanned and unscanned microbial biomass values. We conclude from the literature review and our own experiments that X-ray CT does not impact plant growth or soil microbial populations when employing a low level of dose (<30 Gy. However, the call for higher throughput X-ray CT means that doses that biological samples receive are likely to increase and thus should be closely monitored.

  11. Study on Diagnostic value of X-ray and Spiral CT in Lumbar Vertebrae de-generation%X线片与螺旋CT对腰椎退变的诊断价值研究

    Institute of Scientific and Technical Information of China (English)

    张小凤

    2015-01-01

    目的:探讨腰椎退变采取X线片与螺旋CT的诊断价值。方法整群选取于2013年6月-2014年7月来院诊断的96例腰椎退变患者作为研究对象,所有患者均行X线片及螺旋CT诊断,比较两种诊断方法的影像学表现。结果在诊断腰椎骨质增生及椎间小关节退变方面,X线片的检出率优于CT,差异均有统计学意义;在许莫氏结节方面,CT的检出率(6.25%)优于X线片的(1.04%),差异有统计学意义(χ²=3.8643,P<0.05)。结论CT能直观显示X线片不能显示的某些退变征现象,X线片与螺旋CT诊断结合,对腰椎退变的诊断和治疗有重要作用。%Objective To explore the value of X-ray and spiral CT in the diagnosis of Lumbar Vertebrae degeneration. Methods 96 patients were taken as the research objects which suffered from the osteoarthritis of Lumbar Vertebrae and accepted treatments in our hospital from July, 2013 to July, 2014. these patients were treated by diagnostic X-ray and spiral CT, then, imaging mani-festations of two diagnostic methods were compared. Results In the showing signs of hyperostosis and degeneration of intervertebral small joints and intervertebral space narrowing, X-ray was superior to CT and the differences was statistical significance (P<0.05). In addition, in the showing Schmor's nodes, the detection rate of CT (6.25%) is superior to X-ray (1.04%) and the differences was statistical significance (χ²=3.8643,P<0.05). Conclusion CT can directly display the phenomenon of some degeneration, X-ray can-not. In combination with X-ray and spiral CT diagnosis, it is important for diagnosis and therapy of degenerative lumbar spine.

  12. Study on trace elements behaviour in cancerous and healthy tissues of colon, breast and stomach: Total reflection X-ray fluorescence applications

    Science.gov (United States)

    Magalhães, T.; Carvalho, M. L.; Von Bohlen, A.; Becker, M.

    2010-06-01

    In this work Total-reflection X-ray fluorescence (TXRF) was used to analyse healthy and cancerous tissues of the same individual along several contiguous thin sections of each tissue. Thirty two samples (16 pairs) of breast tissue, 30 samples (15 pairs) of intestine tissue and 10 samples (5 pairs) of stomach tissue were analysed. The samples were obtained in Civil Hospitals of Germany (Dortmund) and Portugal (Lisbon). The elemental distribution of P, S, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr and Pb in these samples was studied. Descriptive statistics based on bar graphics and hypotheses tests and also an automatic classification based on hierarchical grouping analysis was used for the several analysed tissues. It was shown that the behaviour of the elements is tissue dependent. Some elements, like P and K exhibit the same behaviour in all the analysed tissue types. They have increased concentrations in all cancerous tissues. Unlike, other elements like Br show completely different behaviour depending on the tissue: similar concentration in healthy and cancerous stomach, decreased levels in colon cancerous tissues and enhanced concentrations in breast was observed. Moreover cancer tissues present decreased Se concentrations on colon and increased on breast.

  13. Missed diagnosis analysis of occult lung cancer by X-ray and the clinical significance of CT scans%隐匿型肺癌X线胸片漏诊分析及CT扫描的临床意义

    Institute of Scientific and Technical Information of China (English)

    温栋梁

    2014-01-01

    目的:分析 X 线胸片漏诊隐匿性肺癌的原因,并评价 CT 扫描对隐匿性肺癌的诊断价值。方法选择 X 线漏诊的隐匿性肺癌43例患者为研究对象。通过比较 X 线和 CT 检查结果,分析 X 线漏诊原因。结果43例患者正位 X 线胸片结果显示无异常,行侧位 X 线胸片检查后,30例患者依然未见异常。CT 扫描证实43例患者全为隐匿性肺癌。CT 扫描对支气管腔内、肺门区肿块及纵隔淋巴结肿大的显示情况优于 X 线胸片检查,差异有统计学意义(P ﹤0.05)。结论 X 线诊断隐匿性肺癌的漏诊率高。对于疑似隐匿性肺癌的患者,有必要行 CT 扫描,及早发现隐匿性肺癌,进一步确定病情,并采取针对性治疗。%Objective To analyze the missed diagnosis causes of occult lung cancer by X-ray, and evaluate the diagnosis value of CT scans on occult lung cancer. Methods Forty-three patients with occult lung cancer missed diagnosed by X-ray were chose as study objects. By comparing the results of X-ray and CT examination,the missed diagnosis causes of occult lung cancer by X-ray were analyzed. Re-sults The anteroposterior chest X-ray results were not abnormal in all of the 43 patients,and the lateral chest X-ray results were not abnormal in 30 patients. All of the 43 patients were confirmed with occult lung cancer by CT scans. CT scan was superior to the chest X-ray in display the bronchial lumen,lung hilar tumor and mediastinal lymph nodes enlargement,there were significant differences( P ﹤ 0. 05). Conclusions The missed diagnosis rate of occult lung cancer by X-ray is high. For patients with suspec-ted occult lung cancer,CT scan is necessary to early detection of occult lung cancer,further define the disease,and take targeted treatment.

  14. Unwrapping an Ancient Egyptian Mummy Using X-Rays

    Science.gov (United States)

    Hughes, Stephen W.

    2010-01-01

    This article describes a project of unwrapping an ancient Egyptian mummy using x-ray computed tomography (CT). About 600 x-ray CT images were obtained through the mummified body of a female named Tjetmutjengebtiu (or Jeni for short), who was a singer in the great temple of Karnak in Egypt during the 22nd dynasty (c 945-715 BC). The x-ray CT images…

  15. 螺旋CT及X线平片在腕骨隐匿性骨折诊断中的比较分析%Spiral CT and X-ray plain film in the diagnosis of carpal bone occult fracture

    Institute of Scientific and Technical Information of China (English)

    宋春华

    2015-01-01

    Objective To study the carpal bone occult fracture characteristics of spiral CT and X-ray plain film. Methods A retrospective analysis of 46 carpal bone occult fracture cases X-ray films, CT data. Including the review of the data. Results X-ray, suspicious 19 cases of fracture and CT examination all positive, typically characterized by bone cortex lifted, interruption of trabecular bone. Conclusion CT has important significance in avoiding misdiagnosis and carpal bone occult fracture.%目的 探讨螺旋CT及X线平片在腕骨隐匿性骨折检查中的特点.方法 回顾性分析46例腕骨隐匿性骨折的X线片、CT资料. 结果 X线检查阳性1例, 可疑骨折19例,CT阳性后复核X线阳性2例,CT检查44例阳性,典型表现为骨皮质掀起,骨小梁中断.结论 CT检查在避免腕骨隐匿性骨折漏诊中有重要作用,CT阴性应引起重视.

  16. Application of X-ray 3D CT Technology on Electrocomponent Failure Analysis%X射线三维CT技术在元器件失效分析中的应用

    Institute of Scientific and Technical Information of China (English)

    路浩天; 卢晓青; 张祥春; 蔡良续; 吴琼; 张辉

    2012-01-01

    Through comparing the functional characteristics of X-ray, traditional CT and SAM, the advantage of X-ray 3D CT technology was analyzed. With the analysis of solder voids, micro switch and different package components, research on the application of 3D CT technology in electronic component failure analysis was conducted. In addition, according to the feature of X-ray 3D CT imaging, the prospect of this technology was discussed.%通过比较X射线DR,普通断层CT技术,扫描声学显微镜的功能特点,分析了X射线三维CT技术的优势。通过对焊接空洞、微动开关失效案例以及不同封装形式器件的分析,研究了X射线三维CT技术在电子元器件失效分析领域的应用。同时根据X射线三维CT成像的特点,分析了该技术发展的前景。

  17. Diagnosis of sports injuries of the spinal column. If the X-ray doesn`t show enough, CT and MRI will fill the gaps; Diagnostik bei Wirbelsaeulenverletzungen im Sport. Wenn Roentgen nicht alles klaert - dann CT und MRT

    Energy Technology Data Exchange (ETDEWEB)

    Halbsguth, A. [Radiologische Gemeinschaftpraxis, Frankfurt am Main (Germany)

    1996-03-01

    Exact anamnestic exploration is a key to the successful clarification of sports lesions of the spinal column. Today, X-ray diagnostics still is of the greatest importance. Should it be impossible to diagnose the clinical situation extensively by this method recourse should be taken to computed tomography (CT) and nuclear magnetic resonance tomography (NMRT). As a rule, CT is used to clarify bone pathology and NMRT to examine soft tissue lesions. Especially complex vertebral parts - the articlular process and adjacent parts of the transverse process and lamina often are difficult to assess by a sceleton scintigraphy, thus allowing a detailed search using other methods. (orig.) [Deutsch] Die genaue anamnestische Exploration stellt einen wesentlichen Schluessel fuer eine erfolgreiche Abklaerung von Wirbelsaeulenverletzungen im Sport dar. Die Roentigendiagnostik besitzt auch heute noch hoechste Wertigkeit. Laesst sich auf diesem Wege die klinische Situation nicht umfassend diagnostizieren, sollte man auf Computertomographie (CT) und Magnetresonanztomographie (MRT) zurueckgreifen. Knochenpathologie wird in der Regel mit CT und der weichteilbedingte Schaden mit MRT geklaert. Gerade die komplex konfigurierten Wirbelanteile - Processus articulares und benachbarte Anteile von Processus transversus und Lamina - sind nicht selten gut mit der Skelettszintigraphie zu erfassen und erlauben dann eine detaillierte Suche mit anderen Methoden. (orig.)

  18. X-Ray Polarimetry

    CERN Document Server

    Kaaret, Philip

    2014-01-01

    We review the basic principles of X-ray polarimetry and current detector technologies based on the photoelectric effect, Bragg reflection, and Compton scattering. Recent technological advances in high-spatial-resolution gas-filled X-ray detectors have enabled efficient polarimeters exploiting the photoelectric effect that hold great scientific promise for X-ray polarimetry in the 2-10 keV band. Advances in the fabrication of multilayer optics have made feasible the construction of broad-band soft X-ray polarimeters based on Bragg reflection. Developments in scintillator and solid-state hard X-ray detectors facilitate construction of both modular, large area Compton scattering polarimeters and compact devices suitable for use with focusing X-ray telescopes.

  19. CT/FMT dual-model imaging of breast cancer based on peptide-lipid nanoparticles

    Science.gov (United States)

    Xu, Guoqiang; Lin, Qiaoya; Lian, Lichao; Qian, Yuan; Lu, Lisen; Zhang, Zhihong

    2016-03-01

    Breast cancer is one of the most harmful cancers in human. Its early diagnosis is expected to improve the patients' survival rate. X-ray computed tomography (CT) has been widely used in tumor detection for obtaining three-dimentional information. Fluorescence Molecular Tomography (FMT) imaging combined with near-infrared fluorescent dyes provides a powerful tool for the acquisition of molecular biodistribution information in deep tissues. Thus, the combination of CT and FMT imaging modalities allows us to better differentiate diseased tissues from normal tissues. Here we developed a tumor-targeting nanoparticle for dual-modality imaging based on a biocompatible HDL-mimicking peptide-phospholipid scaffold (HPPS) nanocarrier. By incorporation of CT contrast agents (iodinated oil) and far-infrared fluorescent dyes (DiR-BOA) into the hydrophobic core of HPPS, we obtained the FMT and CT signals simultaneously. Increased accumulation of the nanoparticles in the tumor lesions was achieved through the effect of the tumor-targeting peptide on the surface of nanoparticle. It resulted in excellent contrast between lesions and normal tissues. Together, the abilities to sensitively separate the lesions from adjacent normal tissues with the aid of a FMT/CT dual-model imaging approach make the targeting nanoparticles a useful tool for the diagnostics of breast cancer.

  20. Performance simulation of an x-ray detector for spectral CT with combined Si and Cd[Zn]Te detection layers.

    Science.gov (United States)

    Herrmann, Christoph; Engel, Klaus-Jürgen; Wiegert, Jens

    2010-12-21

    The most obvious problem in obtaining spectral information with energy-resolving photon counting detectors in clinical computed tomography (CT) is the huge x-ray flux present in conventional CT systems. At high tube voltages (e.g. 140 kVp), despite the beam shaper, this flux can be close to 10⁹ Mcps mm⁻² in the direct beam or in regions behind the object, which are close to the direct beam. Without accepting the drawbacks of truncated reconstruction, i.e. estimating missing direct-beam projection data, a photon-counting energy-resolving detector has to be able to deal with such high count rates. Sub-structuring pixels into sub-pixels is not enough to reduce the count rate per pixel to values that today's direct converting Cd[Zn]Te material can cope with (≤ 10 Mcps in an optimistic view). Below 300 µm pixel pitch, x-ray cross-talk (Compton scatter and K-escape) and the effect of charge diffusion between pixels are problematic. By organising the detector in several different layers, the count rate can be further reduced. However this alone does not limit the count rates to the required level, since the high stopping power of the material becomes a disadvantage in the layered approach: a simple absorption calculation for 300 µm pixel pitch shows that the required layer thickness of below 10 Mcps/pixel for the top layers in the direct beam is significantly below 100 µm. In a horizontal multi-layer detector, such thin layers are very difficult to manufacture due to the brittleness of Cd[Zn]Te. In a vertical configuration (also called edge-on illumination (Ludqvist et al 2001 IEEE Trans. Nucl. Sci. 48 1530-6, Roessl et al 2008 IEEE NSS-MIC-RTSD 2008, Conf. Rec. Talk NM2-3)), bonding of the readout electronics (with pixel pitches below 100 µm) is not straightforward although it has already been done successfully (Pellegrini et al 2004 IEEE NSS MIC 2004 pp 2104-9). Obviously, for the top detector layers, materials with lower stopping power would be advantageous

  1. X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kalender, Willi A [Institute of Medical Physics, University Erlangen-Nuernberg, Henkestr. 91, D-91052 Erlangen (Germany)

    2006-07-07

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention. (review)

  2. Combined SPECT/CT and PET/CT for breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Paolo [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Larobina, Michele [Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Tommaso De Amicis, 95, Naples I-80145 (Italy); Di Lillo, Francesca [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Del Vecchio, Silvana [Università di Napoli Federico II, Dipartimento di Scienze Biomediche Avanzate, Via Pansini, 5, Naples I-80131 (Italy); Mettivier, Giovanni, E-mail: mettivier@na.infn.it [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy)

    2016-02-11

    In the field of nuclear medicine imaging, breast imaging for cancer diagnosis is still mainly based on 2D imaging techniques. Three-dimensional tomographic imaging with whole-body PET or SPECT scanners, when used for imaging the breast, has performance limits in terms of spatial resolution and sensitivity, which can be overcome only with a dedicated instrumentation. However, only few hybrid imaging systems for PET/CT or SPECT/CT dedicated to the breast have been developed in the last decade, providing complementary functional and anatomical information on normal breast tissue and lesions. These systems are still under development and clinical trials on just few patients have been reported; no commercial dedicated breast PET/CT or SPECT/CT is available. This paper reviews combined dedicated breast PET/CT and SPECT/CT scanners described in the recent literature, with focus on their technological aspects.

  3. Comprehensive Non-Destructive Conservation Documentation of Lunar Samples Using High-Resolution Image-Based 3D Reconstructions and X-Ray CT Data

    Science.gov (United States)

    Blumenfeld, E. H.; Evans, C. A.; Oshel, E. R.; Liddle, D. A.; Beaulieu, K.; Zeigler, R. A.; Hanna, R. D.; Ketcham, R. A.

    2015-01-01

    Established contemporary conservation methods within the fields of Natural and Cultural Heritage encourage an interdisciplinary approach to preservation of heritage material (both tangible and intangible) that holds "Outstanding Universal Value" for our global community. NASA's lunar samples were acquired from the moon for the primary purpose of intensive scientific investigation. These samples, however, also invoke cultural significance, as evidenced by the millions of people per year that visit lunar displays in museums and heritage centers around the world. Being both scientifically and culturally significant, the lunar samples require a unique conservation approach. Government mandate dictates that NASA's Astromaterials Acquisition and Curation Office develop and maintain protocols for "documentation, preservation, preparation and distribution of samples for research, education and public outreach" for both current and future collections of astromaterials. Documentation, considered the first stage within the conservation methodology, has evolved many new techniques since curation protocols for the lunar samples were first implemented, and the development of new documentation strategies for current and future astromaterials is beneficial to keeping curation protocols up to date. We have developed and tested a comprehensive non-destructive documentation technique using high-resolution image-based 3D reconstruction and X-ray CT (XCT) data in order to create interactive 3D models of lunar samples that would ultimately be served to both researchers and the public. These data enhance preliminary scientific investigations including targeted sample requests, and also provide a new visual platform for the public to experience and interact with the lunar samples. We intend to serve these data as they are acquired on NASA's Astromaterials Acquisistion and Curation website at http://curator.jsc.nasa.gov/. Providing 3D interior and exterior documentation of astromaterial

  4. The color of X-rays: Spectral X-ray computed tomography using energy sensitive pixel detectors

    NARCIS (Netherlands)

    Schioppa, E.J.

    2014-01-01

    Energy sensitive X-ray imaging detectors are produced by connecting a semiconductor sensor to a spectroscopic pixel readout chip. In this thesis, the applicability of such detectors to X-ray Computed Tomography (CT) is studied. A prototype Medipix based silicon detector is calibrated using X-ray flu

  5. A breast-specific, negligible-dose scatter correction technique for dedicated cone-beam breast CT: a physics-based approach to improve Hounsfield Unit accuracy

    Science.gov (United States)

    Yang, Kai; Burkett, George, Jr.; Boone, John M.

    2014-11-01

    The purpose of this research was to develop a method to correct the cupping artifact caused from x-ray scattering and to achieve consistent Hounsfield Unit (HU) values of breast tissues for a dedicated breast CT (bCT) system. The use of a beam passing array (BPA) composed of parallel-holes has been previously proposed for scatter correction in various imaging applications. In this study, we first verified the efficacy and accuracy using BPA to measure the scatter signal on a cone-beam bCT system. A systematic scatter correction approach was then developed by modeling the scatter-to-primary ratio (SPR) in projection images acquired with and without BPA. To quantitatively evaluate the improved accuracy of HU values, different breast tissue-equivalent phantoms were scanned and radially averaged HU profiles through reconstructed planes were evaluated. The dependency of the correction method on object size and number of projections was studied. A simplified application of the proposed method on five clinical patient scans was performed to demonstrate efficacy. For the typical 10-18 cm breast diameters seen in the bCT application, the proposed method can effectively correct for the cupping artifact and reduce the variation of HU values of breast equivalent material from 150 to 40 HU. The measured HU values of 100% glandular tissue, 50/50 glandular/adipose tissue, and 100% adipose tissue were approximately 46, -35, and -94, respectively. It was found that only six BPA projections were necessary to accurately implement this method, and the additional dose requirement is less than 1% of the exam dose. The proposed method can effectively correct for the cupping artifact caused from x-ray scattering and retain consistent HU values of breast tissues.

  6. X线与CT诊断骨巨细胞瘤的对比分析%Comparative Analysis of X-ray and CT Diagnosis of Giant Cell Tumor of Bone

    Institute of Scientific and Technical Information of China (English)

    陈军; 王玉清; 刘忠岐

    2015-01-01

    目的:分析X线与CT诊断骨巨细胞瘤的临床效果。方法随机抽取44例骨巨细胞瘤患者,均给予X线与CT诊断。结果44例患者以长骨病变居多,占72.7%;X线显示囊状膨胀性溶骨性骨破坏;CT显示骨囊状膨胀性骨破坏,18例病灶液-液平面,软组织密度不均,骨质破坏边缘清晰。结论 X线与CT对骨巨细胞瘤均具有各自诊断特征,结合多种影像学诊断方法,提高确诊率。%Objective To analyze the clinical effect of X-ray and CT diagnosis of giant cell tumor of bone. Methods Randomly selected 44 cases of giant cell tumor of bone were treated patients, X-ray and CT diagnosis. Results 44 patients with long bone lesions are the most common, accounting for 72.7%; X-ray showed cystic expansile osteolytic bone destruction; CT showed bone cystic and expansive bone destruction, 18 cases were liquid-liquid plane, soft tissue density showed bone destruction, clear edge. Conclusion X-ray and CT had their respective diagnostic features of bone giant cell tumor, diagnosis method combining multiple images, improve the correct diagnosis rate.

  7. 99mTc-MDP骨显像与X线、CT联合诊断SAPHO综合征%Combined diagnosis of SAPHO syndrome by 99mTC-MDP bone imaging, X-ray and CT

    Institute of Scientific and Technical Information of China (English)

    杨中; 徐海青; 吴边; 宋烈晶; 李萌

    2014-01-01

    Objective To compare the image characteristic of SAPHO syndrome by X-ray and CT findings as well as 99mTC-MDP bone imaging for accurate diagnosis of this entity. Methods The imaging prop⁃erty was examined on X-ray, CT and 99mTC-MDP bone imaging in 22 cases and compared with the advantag⁃es and disadvantages. Results SAPHO syndrome presented distinctive features by different imaging technique, and the nature appeared prominent on X-ray and CT images, yet was more sensitive to 99mTC-MDP. Conclu⁃sion Patients with suspected SAPHO syndrome may receive early examination by X-ray or CT, and addition⁃al nuclide bone imaging, as appropriate, may improve the diagnostic accuracy.%目的:比较分析SAPHO综合征X线、CT和核素骨显像影像特征,提高本病正确诊断率。方法通过对该病22例的X线、CT和核素骨显像图像分析,总结各自的影像学特性,并对比各自的优缺点。结果 SAPHO综合征在各种成像上都有特征性的表现,但X线、CT特征性更突出,而核素骨显像敏感性更高。结论对可疑SAPHO综合征患者,应及早行X线或CT检查,必要时加做核素骨显像来提高诊断准确率。

  8. 骨纤维异常增殖症影像诊断对比分析%Analysis of manifestations of Fibrous Dysplasia of Bone on X - ray and CT Scan

    Institute of Scientific and Technical Information of China (English)

    韦林森; 韦东风; 张克池

    2011-01-01

    目的对骨纤维异常增殖症的X线与CT诊断分析.方法回顾性分析54例由病理证实的骨纤维异常增殖症的X线与CT征象特点.结果54例中单骨型33例,多骨型19例,Albright综合症2例.X线表现比较复杂,常见有囊状改变、毛玻璃样改变、丝瓜瓤样改变及虫蚀样改变4种骨改变.CT表现有囊状低密度影、毛玻璃样改变、斑块样硬化.结论骨纤维异常增殖症的影像诊断以X线平片为首选,头颅等较复杂部位的影像诊断以CT为佳.%Objective To analyze the manifestations of fibrous dysplasia of bone(FDB) on X - ray and CT.Methods Fifty - four cases with FDB confirmed by pathology were enrolled in the study and their manifestations of FDB on X - ray and CT were reviewed.Results Out of 54 cases, 33 showed fibrous dysplasia of single bone, 19 showed fibrous dysplasia of multi - bones and the rest two showed Albright syndrome.X - ray performance was more complex with common signs of pouch shape change, rough hyalo- like change, sponge groud- flesh type and moth- eaten type.CT features of lesions were pouch shape low density shade, rough hyalo - like change and motting type hardening.Conclusion X - ray film should be the first choice in diagnosis of fibrous dysplasia.CT is highly sensitive in displaying lesions of more complex parts, like skull.

  9. Laboratory Seismic Monitoring and X-ray CT imaging of Supercritical CO2 Injection in Reservoir Sand: WESTCAB King Island Project

    Science.gov (United States)

    Nakashima, S.; Kneafsey, T. J.; Nakagawa, S.; Harper, E. J.

    2013-12-01

    The Central Valley of California contains promising locations for on-shore geologic CO2 storage. DOE's WESTCARB (West Coast Regional Carbon Sequestration Partnership) project drilled and cored a borehole (Citizen Green Well) at King Island (near Stockton, CA) to study the CO2 storage capability of saline and gas-bearing formations in the southwestern Sacramento Basin. Potential reservoirs encountered in the borehole include Domengine, Mokelumne River (primary target), and Top Starkey formations. In anticipation of geophysical monitoring of possible CO2 injection into this particular borehole and of the long-term migration of the CO2, we conducted small-scale CO2 injection experiments on three core samples retrieved from the well (Mokelumne River sand A and B) and from a mine outcrop (Domengine sandstone). During the experiment, a jacketed core sample (diameter 1.5 inches, length 4.0-6.0 inches) saturated with brine- (1% NaCl aq.) was confined within a pressure vessel via compressed nitrogen to 3,500-4,000psi, and supercritical CO2 was injected into the core at 2,000-2,500psi and 45-60 degrees C. The CO2 pressure and temperature were adjusted so that the bulk elastic modulus of the CO2 was close to the expected in-situ modulus--which affects the seismic properties most--while keeping the confining stress within our experimental capabilities. After the CO2 broke through the core, fresh brine was re-injected to remove the CO2 by both displacement and dissolution. Throughout the experiment, seismic velocity and attenuation of the core sample were measured using the Split Hopkinson Resonant Bar method (Nakagawa, 2012, Rev. Sci. Instr.) at near 1 kHz (500Hz--1.5 kHz), and the CO2 distribution determined via x-ray CT imaging. In contrast to relatively isotropic Mokelumne sand A, Domengine sandstone and Mokelumne sand B cores exhibited CO2 distributions strongly controlled by the bedding planes. During the CO2 injection, P-wave velocity and attenuation of the layered

  10. Three-dimensional analysis of vesicle and crystal fragment textures in pumice using high-resolution X-ray CT: Textural evidence of eruptive processes

    Science.gov (United States)

    Ketcham, R. A.; Gardner, J. E.; Abbott, S.

    2011-12-01

    Three-dimensional analysis of high-resolution X-ray computed tomographic (CT) imagery of pumice from Popocatépetl Volcano in central Mexico yields fresh insights into processes of vesicle formation and coalescence and crystal fragmentation that occur during explosive volcanism. Six ~2 cm pumice fragments of varying bulk vesicularity were imaged at ~20 μm resolution. Three-dimensional blob and fabric analysis quantitatively document textural features, and visualization facilitated contextualization of measurements and overall interpretation. Vesicles range in size from mm-scale to below the resolution of the scan data. By comparing the whole-sample 3D vesicle size distributions derived from CT with more detailed distributions from sub-volumes obtained by standard petrographic analysis, we can discern two distinct, roughly log-normal populations in each sample. Vesicles in all samples have preferred orientations, and fabric analysis based on the star volume distribution and displayed as 3D rose diagrams documents a range of preferred shapes from elongate to flattened. Aspect ratios range from 1 to 6, and converge to values of ~2-3 with increasing size. Surface to volume ratios show increasing departure from sphericity with increasing size, which is probably attributable in large part to irregular shapes caused by coalescence. The vesicle fabric was strongest in the highest-vesicularity sample. Some pumices showed evidence of welding or poor mixing between two or more differently devolatilized portions of melt. Interfaces are in some cases apparently welded, with low-vesicularity glass contact zones, and in others are simply sub-planar intersections between distinct glasses. In one instance of the latter, correlated vesicle and phenocryst orientations across both melt portions and not parallel to their interface suggests that their juxtaposition took place before final eruption, while there was still time for fabric development. The pumices show abundant evidence of

  11. X ray and CT imaging in the diagnosis of the application of the ischemic necrosis of femoral head%X射线与CT影像在诊断股骨头缺血性坏死中的应用

    Institute of Scientific and Technical Information of China (English)

    王永存; 马献武

    2015-01-01

    Objective:To investigate the diagnosis value of the X-ray and CT imaging, in the ischemic necrosis of femoral head.Methods: Seventy cases of patients with ischemic necrosis of femoral head were given X ray examination and CT examination, comparing two test results of two methods of inspection.Results: The result of statistical analysis, the rate of X-ray examination was 55.7%, the rate of CT examination was 81.4%. By chisquare test, CT examination compared with X-ray had significant difference (x2=1.389,P<0.05).Conclusion: Compared with X-rays, the sensitivity of CT examination in early diagnosis of avascular necrosis is high; CT examination is an effective method in early diagnosis of ischemic necrosis of femoral head.%目的:探讨X射线与CT影像在诊断股骨头缺血性坏死中的应用价值。方法:选取70例股骨头缺血性坏死患者的X射线和CT影像学资料,所有患者均行X射线和CT检查,比较两种检查方法的诊断结果。结果:在70例患者中,股骨头缺血性坏死X射线检查早期发现率为55.7%,CT检查早期发现率为81.4%。两种检查方式早期发现率比较差异有统计学意义(x2=1.389,P<0.05)。结论:CT检查与X射线相比,对于股骨头缺血性坏死的早期诊断灵敏度高,是股骨头缺血性坏死早期诊断的有效方法。

  12. X-ray source for mammography

    Science.gov (United States)

    Logan, Clinton M.

    1994-01-01

    An x-ray source utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms.

  13. Efficacy of breast shielding during CT of the head

    Energy Technology Data Exchange (ETDEWEB)

    Brnic, Z.; Hebrang, A.; Anic, P. [Department of Diagnostic and Interventional Radiology, University Hospital Merkur, Zajceva 19, 10000, Zagreb (Croatia); Vekic, B. [' ' Ruder Boskovic' ' Research Institute, 10000, Zagreb (Croatia)

    2003-11-01

    In light of increasing frequency of CT examinations in the past decades, the aims of this prospective study were to investigate scatter radiation breast exposure in head CT and its dependence upon body constitution, and to assess the efficacy of lead shielding as a means of breast dose reduction. In 49 women referred to head CT for objective medical reasons one breast was covered with lead apron during CT scanning. Radiation doses were measured by use of thermoluminescent dosimeters, at skin of both breasts and over the apron. The doses were then compared as well as correlated to body mass index and meatus acusticus externus-to-dosimeter distance, respectively. Average exposure at the skin of the unshielded breast was 0.28 mGy (range 0.15-0.41 mGy), compared with 0.13 mGy (range 0.05-0.29 mGy) at the shielded breast. The doses showed a mean reduction by 57% due to lead shielding. At least half of breast exposure was imparted to the breast from outside, whereas the remainder results from internal scatter. The higher the body mass index, the higher the percentage of internal scatter in total breast dose. Although the level of scatter radiation to the breast is generally low during head CT examination, the use of lead cover enables recognizable further reduction of the exposure, and is recommended as a feasible and effective procedure of breast protection during CT of the head. (orig.)

  14. Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

    Science.gov (United States)

    Zhao, C.; Vassiljev, N.; Konstantinidis, A. C.; Speller, R. D.; Kanicki, J.

    2017-03-01

    High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 µm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30°. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g.  ±30°) improves the low spatial frequency (below 5 mm‑1) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used. Theoretical analysis suggests that a pixelated scintillator in combination with the 50 µm pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared.

  15. Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis.

    Science.gov (United States)

    Zhao, C; Vassiljev, N; Konstantinidis, A C; Speller, R D; Kanicki, J

    2017-03-07

    High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 µm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30°. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g.  ±30°) improves the low spatial frequency (below 5 mm(-1)) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used. Theoretical analysis suggests that a pixelated scintillator in combination with the 50 µm pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared.

  16. Dental x-rays

    Science.gov (United States)

    ... X-rays are a form of high energy electromagnetic radiation. The x-rays penetrate the body to form ... for detecting cavities, unless the decay is very advanced and deep. Many ... The amount of radiation given off during the procedure is less than ...

  17. The clinical value of the mammography X-ray, ultrasound and MRI for the qualitative diagnosis of breast cancer%钼靶X射线、超声及MRI对乳腺癌诊断的应用价值

    Institute of Scientific and Technical Information of China (English)

    赵军

    2014-01-01

    Objective:To evaluate the diagnostic value of the mammography X-ray, ultrasound and MRI for breast cancer, expected to provide a reference for the clinical diagnosis of these diseases. Methods:117 cases patients with suspected breast cancer were the objects of the study, compared the results of the detection with mammography X-ray, ultrasound and MRI between the results of pathological examination, to investigate the diagnostic ability of different image means for all types of breast disease.Results:The sensitivity, accuracy of MRI for breast cancer were better than X-ray mammography and ultrasound, but the speciifcity was similar with X-ray mammography. Compared ultrasound, the specificity, positive predictive value of X-ray mammography was much higher, but had no advantage in the other parameters related with diagnostic capabilities.Conclusions:Mammography X-ray, ultrasound and MRI have their own advantages and disadvantages for the diagnosis of breast diseases, but the mammography X-ray can be as the preferred means for the ifrst diagnosis of breast cancer, and multiple imaging means could be joint based on the needs of clinical diagnosis.%目的:探讨钼靶X射线、超声及MRI对乳腺癌的临床诊断价值。方法:以117例疑似乳腺癌患者为研究对象,将钼靶X射线、超声及MRI检查结果与病理诊断结果对比,考察不同影像手段对各类乳腺疾病的诊断能力。结果:MRI对乳腺癌的敏感性、准确度等均优于钼靶X射线和超声,但特异性与钼靶X射线相当。与超声相比,钼靶X射线的特异性、阳性预测值较高,但在其他诊断能力相关的参数方面则无优势。结论:钼靶X射线、超声及MRI在诊断乳腺疾病方面各有优劣,但钼靶X射线可作为乳腺癌临床初诊的首选手段,临床确诊时可联用多种影像手段。

  18. [Breast dose reduction in female CT screening for lung cancer using various metallic shields].

    Science.gov (United States)

    Takada, Kenta; Kaneko, Junichi; Aoki, Kiyoshi

    2009-12-20

    We evaluated the effectiveness of metallic shields that were used for reduction of the breast dose in thoracic computed tomography(CT). For the evaluation, we measured breast surface dose and image standard deviation(SD)in the lung area. The metallic shields were made from bismuth, zinc, copper, and iron. The bismuth shield has been marketed and used for dose reduction. The other three metallic shields were chosen because they have lower atomic numbers and a lower yield of characteristic X-rays. As a result, use of the metallic shields showed a lower breast dose than the decrement of the tube current in the same image SD. The insertion of a thin aluminum sheet between the shield and a phantom was also effective in reducing breast surface dose. We calculated the dose reduction rate to evaluate the effectiveness of these metallic shields. This dose reduction rate was defined as the ratio of the decrease in breast surface dose by metallic shields to the breast surface dose measured with the tube current decrement in the same image SD. The maximum dose reduction rate was 6.4% for the bismuth shield, and 12.0-13.3% for the other shields. These results indicate that the shields made from zinc, copper, and iron are more effective for dose reduction than the shield made form bismuth. The best dose reduction rate, 13.3%, has been achieved when the zinc shield placed 20 mm apart from a phantom with 0.2 mm aluminum was used.

  19. X-Ray Surveys

    CERN Document Server

    Giommi, P; Perri, M

    1998-01-01

    A review of recent developments in the field of X-ray surveys, especially in the hard (2-10 and 5-10 keV) bands, is given. A new detailed comparison between the measurements in the hard band and extrapolations from ROSAT counts, that takes into proper account the observed distribution of spectral slopes, is presented. Direct comparisons between deep ROSAT and BeppoSAX images show that most hard X-ray sources are also detected at soft X-ray energies. This may indicate that heavily cutoff sources, that should not be detectable in the ROSAT band but are expected in large numbers from unified AGN schemes, are in fact detected because of the emerging of either non-nuclear components, or of reflected, or partially transmitted nuclear X-rays. These soft components may complicate the estimation of the soft X-ray luminosity function and cosmological evolution of AGN.

  20. Contrast-enhanced dedicated breast CT detection of invasive breast cancer preceding mammographic diagnosis

    Directory of Open Access Journals (Sweden)

    Nicolas D. Prionas, MD, PhD

    2015-01-01

    Full Text Available Dedicated breast computed tomography (bCT generates high-resolution, three-dimensional images of the pendent uncompressed breast. Intravenous iodinated contrast during bCT provides additional physiologic information. In this case, a 10.0-mm invasive ductal carcinoma was visualized using contrast-enhanced breast CT one year before mammographic detection. Mammography four months before bCT was negative. The bCT contrast enhancement pattern closely matched the dynamic contrast-enhanced MRI obtained after diagnosis. Lesion enhancement at contrast-enhanced breast CT matched previously published enhancement values of breast cancer. Contrast-enhanced dedicated bCT provided high-resolution tomographic images and physiologic contrast enhancement data that facilitated the detection of an early breast cancer.

  1. 髋臼隐匿性骨折CT与X线平片检查诊断率对比分析%Comparative Analysis of CT and X-ray Diagnosis Rate of Occult Acetabulum Fracture

    Institute of Scientific and Technical Information of China (English)

    李国良

    2011-01-01

    Objective To investigate the appropriate diagnostic imaging method for evaluating occult acetabulum fracture in order to improve the diagnostic accuracy. Methods Retrospective analysis of 48 patients with occult acetabulum fracture was undertaken by X-ray and CT scans. We evaluated the detection rate of occult acetabulum fracture between CT and X-ray. Results According to Letournel Classification, there were 16 cases of anterior wall, 14 cases of posterior wall, 8 cases of anterior column and 10 cases of posterior column fractures. 28 (58.3% ) patients were suspected as having fracture line on the X -ray film. On the contrary, 48 (100.0% ) patients demonstrated occult acetabulum fracture line on CT. Conclusion CT has higher sensitivity than X-ray in detecting occult acetabulum fracture. Compared with X-ray, CT scanning allows a more precise determination of the degree of occult acetabulum fracture involvement and therefore is helpful in the planning of orthopedic surgery.%目的 探讨髋臼隐匿性骨折适宜的影像学诊断方法,提高其诊断准确性.方法 回顾性分析48例髋臼隐匿性骨折CT与X线平片影像学资料,评价CT与X线平片检查对髋臼隐匿性骨折的诊断率.结果 本组48例按Letournel分类,骨折位于髋臼前壁16例、后壁14例、前柱8例、后柱10例.CT检查诊断髋臼隐匿性骨折48例,诊断率100.0%;X线平片检查疑有髋臼隐匿性骨折28例,诊断率58.3%.结论 CT检查对髋臼隐匿性骨折的诊断率明显高于X线平片检查,X线平片检查可作为髋臼隐匿性骨折的初筛方法,CT检查则可为髋臼隐匿性骨折及其伴随损伤提供更准确的诊断信息.

  2. Classification of breast tissue using a laboratory system for small-angle x-ray scattering (SAXS)

    Science.gov (United States)

    Sidhu, S.; Falzon, G.; Hart, S. A.; Fox, J. G.; Lewis, R. A.; Siu, K. K. W.

    2011-11-01

    Structural changes in breast tissue at the nanometre scale have been shown to differentiate between tissue types using synchrotron SAXS techniques. Classification of breast tissues using information acquired from a laboratory SAXS camera source could possibly provide a means of adopting SAXS as a viable diagnostic procedure. Tissue samples were obtained from surgical waste from 66 patients and structural components of the tissues were examined between q = 0.25 and 2.3 nm-1. Principal component analysis showed that the amplitude of the fifth-order axial Bragg peak, the magnitude of the integrated intensity and the full-width at half-maximum of the fat peak were significantly different between tissue types. A discriminant analysis showed that excellent classification can be achieved; however, only 30% of the tissue samples provided the 16 variables required for classification. This suggests that the presence of disease is represented by a combination of factors, rather than one specific trait. A closer examination of the amorphous scattering intensity showed not only a trend of increased scattering intensity with disease severity, but also a corresponding decrease in the size of the scatterers contributing to this intensity.

  3. 少见纵隔肿瘤的X线、CT诊断(附9例报告)%Unusual Mediastinal Tumors:X-ray and CT Diagnosis (A Report of 9 Cases)

    Institute of Scientific and Technical Information of China (English)

    施明; 申全谋; 何丽馥; 姚晓新

    2001-01-01

    目的:探讨X线、CT诊断少见纵隔肿瘤的价值。方法:9例病例均行普通X线正侧位或斜位照片,CT扫描均为平扫,层厚为10 mm。结果:9例都经手术病理证实(其中脂肪肉瘤2例,多发性神经鞘瘤2例,神经内分泌癌2例,胸腺类癌1例,内胚窦瘤2例)。结论:X线、CT可做出纵隔肿瘤的定位诊断,CT对纵隔肿瘤的内部形态及其与周围组织结构关系的进一步判断更具意义。但X线、CT对一些肿瘤的定性诊断仍存在一定的限度。%Objective:To explore the clinical value of X-ray and CT in detecting unusual mediastinal mass.Methods:The chest plain films and CT scans were performed in all 9 cases .Results:Nine cases proved by operation and pathology included liposarcoma(two cases),multiple neurinoma(two cases),neuroendovrine cartinoma(two cases),endodermal sinus tumor(two cases)and thymas cacinoid (one case).Conclusion:X-ray and CT can localze the mediastinal mass,CT has more significance in detecting the internal morphology of mediastinal mass and its relationship with the surrounding tissues.But there is still a limitation for X-ray and CT in detecting the quality of some mediastinal carcinomas.

  4. X-ray crystallography

    Science.gov (United States)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  5. Molybdenum Target X Ray Film and MRI in the Diagnosis of Breast Diseases%钼靶X线片与MRI在诊断乳腺疾病上的对比观察

    Institute of Scientific and Technical Information of China (English)

    兰勇军; 毕力克孜; 陈琼

    2015-01-01

    目的:比较钼靶X线片与MRI在诊断乳腺疾病中的价值。方法本文通过分别分析钼靶X线检查与MRI检查在诊断乳腺疾病上的意义,比较钼靶X线片与MRI的优劣势。结果钼靶X线片检查是诊断乳腺疾病的金标准,MRI检查乳腺疾病具有较高的诊断率及敏感度。结论可将这两种检查方式结合使用,取长补短,提高乳腺疾病的诊断率,从而给予患者早期治疗干预,降低乳腺癌的发生,提高患者的生存质量。%Objective To comparare the values of X-ray mammography and MRI in the diagnosis of breast disease.Methods This text comparares the advantages and disadvantages of X-ray mammography and MRI by separately analyzing significances of X-ray mammography and MRI in the diagnosis of breast disease.ResultesMammography X-ray examination is the gold standard for the diagnosis of breast disease,while MRI has higher diagnosis rates and sensitivity in the examination of breast disease.Conclusion These two checks can be combined through drawing on each others' strength to improve the diagnosis rates of breast disease,giving patients early therapeutic intervention to reduce the occurrence of breast cancer and improve the quality of patients' life.

  6. WE-FG-207A-02: Why We Need Breast CT? - Clinical Perspective.

    Science.gov (United States)

    O'Connell, A

    2016-06-01

    dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1-8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In

  7. WE-FG-207A-01: Introduction to Dedicated Breast CT - Early Studies.

    Science.gov (United States)

    Vedantham, S

    2016-06-01

    dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1-8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In

  8. WE-FG-207A-00: Advances in Dedicated Breast CT.

    Science.gov (United States)

    Vedantham, Srinivasan; Molloi, Sabee

    2016-06-01

    dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1-8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In

  9. WE-FG-207A-04: Performance Characteristics of Photon-Counting Breast CT.

    Science.gov (United States)

    Kalender, W

    2016-06-01

    dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1-8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In

  10. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  11. Atypical osteomyelitis of the X-ray,CT and MR imaging is analyzed%不典型骨髓炎的X线、CT和MR影像比较分析

    Institute of Scientific and Technical Information of China (English)

    范光文; 姜妮妮; 韩兵

    2014-01-01

    Objective To discuss the atypical osteomyelitis of the X-ray,CT and MR imaging. Methods In our hospital were retrospectively analyzed in this paper at the same time to do the examination such as X-ray,CT and MR and confirmed by pathology in 20 patients with atypical osteomyelitis of image data,observation of atypical osteomyelitis X-ray,CT and MR imaging characteristics. Results X-ray can find obvious periosteal reaction and bone cortex thickening,bone destruction,bone sclerosis,the involvement of the medullary cavity,dead bone formation and soft tissue swelling.Periosteal reaction and CT examination in found dead bone formation has the advantage.MRI in bone destruction,the involvement of the medullary cavity,has the advantages of soft tissue swelling.In the diagnosis of atypical osteomyelitis,spiral CT and MRI is superior to X-ray. Conclusion CT and MRI in the diagnosis of atypical osteomyelitis contrast X-ray have certain advantages,but X-ray possesses the advantages of fast,cheap,has a certain advantage in disease census,three kinds of complementary can be more accurate diagnosis of atypical osteomyelitis.%目的:讨论不典型骨髓炎的X线、CT和MR影像比较。方法本文回顾性分析在本院同时做X线、CT和MR等检查且经病理证实的20例不典型骨髓炎患者的影像资料,观察不典型骨髓炎X线、CT和MR等影像特点。结果 X线检查可以发现明显的骨膜反应、骨皮质增厚、骨质破坏、骨质硬化、髓腔受累、死骨形成、软组织肿胀。CT检查在发现骨膜反应、死骨形成方面具有优势。MRI检查在发现骨质破坏、髓腔受累、软组织肿胀方面具有优势。在诊断不典型骨髓炎方面,螺旋CT及MRI检查优于X线检查。结论 CT、MRI对不典型骨髓炎的诊断对比X线检查有一定优势,但X线检查具有快捷、费用低廉的优点,在疾病的普查方面具有一定优势,3种检查互补可以更加准确的诊断不典型骨髓炎。

  12. 胸部X线、CT和纤维支气管镜对肺癌诊断的应用研究%Study of Diagnosis of Chest X ray, CT and Bronchoscopy in Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    董乐; 张锡海; 韩璐璐; 刘钊

    2015-01-01

    Objective To analyze and discuss the meaning and value of chest X-ray, CT and fibrobronchoscope. Methods Select-ed 140 cases of patients with lung cancer in our hospital from January 2013 to January 2015 as a study object, according to the different of imaging detection scheme divided into CT group, X-gray group and fibrobronchoscope group, and analysis of the effect of the three detection methods in the treatment of patients. Results The accuracy rate of X-ray was 171/235 (72.77%), accuracy of CT examination for 211/235 (89.79%), the accuracy rate of fiberoptic bronchoscopy for 221/235 (94.04%) was higher than that of X-ray, CT, there was significant difference(χ2=5.37, P<0.05); fiberoptic bronchoscopy was higher than that of X-ray, there were statistically significant differences (χ2=6.81,P<0.05);fiberoptic bronchoscopy the mirror is higher than that of CT, but the difference was not statistically significant(χ2=0.67, P<0.05).Over 60% lung cancer patients can be clinically diagnosed only by chest X-ray, the accurate rate of peripheral lung cancer can be diagnosed by CT while central lung cancer can be diagnosed by fibrobroncho-scope. Conclusion It was showed that Chest X-ray should be used firstly in the diagnosis of lung cancer, and CT or fibrobroncho-scope can greatly improve the diagnostic accuracy of lung cancer, which is worthy of promotion and application.%目的 分析和研究胸部X线、 螺旋 CT及纤维支气管镜在诊断中的价值和意义. 方法 随机抽取于 2013年1月-2015年1月间在该院就诊的140例肺癌患者作为研究对象,并根据检查方法的不同分为X线、CT、支气管镜,所有患者均进行以上检查,对比和分析各种方法在诊断中的准确性. 结果 X线检查的准确率为171/235(72.77%),CT检查的准确率为211/235(89.79%),纤维支气管镜的准确率为221/235(94.04%),CT高于X线,差异有统计学意义(χ2=5.37,P<0.05);纤维支气管镜高于X线,差异有统计学意义(χ2=6.81,P<0

  13. Attenuation properties and percentage depth dose of tannin-based Rhizophora spp. particleboard phantoms using computed tomography (CT) and treatment planning system (TPS) at high energy x-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Yusof, M. F. Mohd, E-mail: mfahmi@usm.my [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); School of Health Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan (Malaysia); Abdullah, R. [School of Health Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan (Malaysia); Tajuddin, A. A. [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200 Kepala Batas, Penang (Malaysia); Hashim, R. [School of Industrial Technologies, Universiti Sains Malaysia, 11800 Penang (Malaysia); Bauk, S. [Physics Section, School of Distance Education, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2016-01-22

    A set of tannin-based Rhizophora spp. particleboard phantoms with dimension of 30 cm x 30 cm was fabricated at target density of 1.0 g/cm{sup 3}. The mass attenuation coefficient of the phantom was measured using {sup 60}Co gamma source. The phantoms were scanned using Computed Tomography (CT) scanner and the percentage depth dose (PDD) of the phantom was calculated using treatment planning system (TPS) at 6 MV and 10 MV x-ray and compared to that in solid water phantoms. The result showed that the mass attenuation coefficient of tannin-based Rhizohora spp. phantoms was near to the value of water with χ{sup 2} value of 1.2. The measured PDD also showed good agreement with solid water phantom at both 6 MV and 10 MV x-ray with percentage deviation below 8% at depth beyond the maximum dose, Z{sub max}.

  14. X-Ray Diffraction.

    Science.gov (United States)

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  15. Pelvis x-ray

    Science.gov (United States)

    X-ray - pelvis ... Tumors Degenerative conditions of bones in the hips, pelvis, and upper legs ... hip joint Tumors of the bones of the pelvis Sacroiliitis (inflammation of the area where the sacrum ...

  16. X-ray - skeleton

    Science.gov (United States)

    ... x-ray particles pass through the body. A computer or special film records the images. Structures that ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  17. Bone x-ray

    Science.gov (United States)

    ... or broken bone Bone tumors Degenerative bone conditions Osteomyelitis (inflammation of the bone caused by an infection) ... Multiple myeloma Osgood-Schlatter disease Osteogenesis imperfecta Osteomalacia Osteomyelitis Paget disease of the bone Rickets X-ray ...

  18. Hand x-ray

    Science.gov (United States)

    ... include fractures, bone tumors , degenerative bone conditions, and osteomyelitis (inflammation of the bone caused by an infection). ... chap 46. Read More Bone tumor Broken bone Osteomyelitis X-ray Review Date 9/8/2014 Updated ...

  19. Chest X-Ray

    Medline Plus

    Full Text Available ... breath, persistent cough, fever, chest pain or injury. It may also be useful to help diagnose and ... have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to ...

  20. The Analysis of Molybdenum X-ray Mammography in the Diagnosis of 33 Cases of Breast Cancer%乳腺癌的钼靶诊断33例分析

    Institute of Scientific and Technical Information of China (English)

    刘燕飞; 王国华; 罗庆华

    2013-01-01

      目的:总结本院乳腺钼靶摄片对诊断乳腺癌的经验,探讨钼靶X线检查及其影像表现对乳腺癌的诊断价值。方法:回顾性分析本院乳腺钼靶X线检查诊断怀疑为乳腺癌并有病理结果的33例患者的X线影像表现。结果:33例患者中,经手术病理确诊为乳腺癌的有23例(69.7%)。良性病例10例(30.3%),其中1例不典型增生,1例乳头状瘤伴不典型增生。结论:钼靶X线检查对乳腺癌的诊断有价值,也是目前能够及时发现并确诊乳腺癌的比较简单方便而又经济的方法。%Objective:To summarize the experience of the diagnosis of breast cancer with molybdenum X-ray mammography,to explore the diagnostic value of the molybdenum X-ray mammography and its imaging finding for the breast cancer.Method:Retrospective analysis of the breast molybdenum target X-ray diagnosis of X-ray images of 33 patients with suspected breast cancer and pathological results of performance.Result:In the 33 suspected breast cancer cases,23 cases by surgery pathology diagnosed with breast cancer(69.7%),other 10 cases of benign cases(30.3%),atypical hyperplasia 2 cases(6.1%).Conclusion:Molybdenum X-ray mammography is valuable in the diagnosis of breast cancer,and it is simple and economic method to timely discover and accurate diagnose the breast cancer at the moment.

  1. Accuracy and the influence of marrow fat on quantitative CT and dual-energy X-ray absorptiometry measurements of the femoral neck in vitro

    NARCIS (Netherlands)

    J.W. Kuiper; C. van Kuijk (Cornelis); J.L. Grashuis (Jan); A.G.H. Ederveen (Antwan); H.E. Schütte (Henri)

    1996-01-01

    markdownabstractAbstract Bone mineral measurements with quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA) were compared with chemical analysis (ChA) to determine (1) the accuracy and (2) the influence of bone marrow fat. Total bone mass of 19 human femoral necks in

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... that might interfere with the x-ray images. Women should always inform their physician and x-ray ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  4. Comparative analysis of hyaline membrane disease with X-ray films and CT diagnosis%新生儿肺透明膜病X线片与CT诊断对照分析

    Institute of Scientific and Technical Information of China (English)

    林华云; 林云亮

    2012-01-01

    目的 对新生儿肺透明膜病X线片和CT诊断结果进行比较分析,并探讨其应用.方法 选取2009年11月~2011年11月于我院诊治的新生儿肺透明膜病患儿50例,对照其临床治疗过程中的X线片与CT影像学资料,观察分析诊断结果.结果 新生儿肺透明膜病的典型病症包括胸片表现的细颗粒状、网格状、支气管充气征以及两肺野透亮度减低等,并发症包括肺出血、肺炎和气胸等.分析表明,肺部病变检出率CT扫描与X线片二者比较差异有高度统计学意义(P < 0.01);并发症检出率CT扫描与X线片二者比较差异有统计学意义(P < 0.05).结论 X线片与CT对新生儿肺透明膜病的诊断是相互补充的,对临床高度可疑但X线片观察不能排除的患儿,应及时实施CT扫描,这对该疾病的鉴别诊断以及发现并发症等具有重要的指导性意义.%Objective To compare and analyse the results of the neonatal hyaline membrane disease X-ray films and CT diagnosis and explore its applications. Methods 50 cases hyaline membrane disease children from November 2009 to November 2011 in our hospital was selected, its clinical treatment in the process of X-ray film and CT imaging data was analysised, to the results of the diagnosis were observed and analyzed. Results Neonatal hyaline membrane disease typical symptoms, including chest X-ray performance of fine granular grid, air bronchogram, and two lung fields through the brightness to reduce and so on. The complications include pulmonary hemorrhage, pneumonia and pneumothorax. The analysis showed that the lung lesion detection rate of CT scan and X-ray film contrast the two was statistically significant (P < 0.01). Contrasted CT scan and X-ray film detection rate of complications, and the difference was statistically significant (P < 0.05). Conclusion X-ray films and CT complement each other hyaline membrane disease diagnosis, highly suspicious of clinical X-ray film observation can not

  5. Line-Source Based X-Ray Tomography

    Directory of Open Access Journals (Sweden)

    Deepak Bharkhada

    2009-01-01

    Full Text Available Current computed tomography (CT scanners, including micro-CT scanners, utilize a point x-ray source. As we target higher and higher spatial resolutions, the reduced x-ray focal spot size limits the temporal and contrast resolutions achievable. To overcome this limitation, in this paper we propose to use a line-shaped x-ray source so that many more photons can be generated, given a data acquisition interval. In reference to the simultaneous algebraic reconstruction technique (SART algorithm for image reconstruction from projection data generated by an x-ray point source, here we develop a generalized SART algorithm for image reconstruction from projection data generated by an x-ray line source. Our numerical simulation results demonstrate the feasibility of our novel line-source based x-ray CT approach and the proposed generalized SART algorithm.

  6. X线与CT诊断对成软骨细胞瘤的诊断价值对比分析%Comparative analysis of X-ray and CT diagnosis of chondroblastoma

    Institute of Scientific and Technical Information of China (English)

    杨旭华; 刘晓梅

    2012-01-01

    Objective To investigate the comparative value of X-ray and CT diagnosis of chondroblastoma and to improve the level of diagnosis of this disease. Methods 32 patients with chondroblastoma from June 2002 to March 2011 were selected to do the X-ray and CT scan. Results X-ray showed that the lesions were round or irregular in shape limitations of bone destruction, CT showed the lesions were va-ryed degrees of lobulated border and clear,semi-annular calcification. According to the pathological findings,the sensitivity of X-ray diagnostic was 96. 2% , specificity was 16. 7% ; the sensitivity and specificity of CT diagnostic were respectively 96. 8% and 100. 0% . The two sets of diagnostic sensitivity were relatively high and had no significant difference. But the specificity of CT in the diagnosis was significantly higher than the X-ray diagnosis ( P <0. 05 ). Conclusion Both the X-ray and CT scan diagnosis of chondroblastoma have its own advantages, but the specificity of CT is better, combination of the two can provide more diagnostic information in clinical applications, which is value to the diagnosis and differential diagnosis.%目的 探讨X线与CT诊断对成软骨细胞瘤的诊断价值,提高对本病的诊断水平.方法 收集2002年6月至2011年3月拟诊断为成软骨细胞瘤患者32例,均行X线和CT检查.结果 X线显示病灶均为圆形或不规则形局限性骨破坏区,CT显示病灶呈不同程度的分叶状,边界清楚,半环形钙化.以病理结果 为标准判断,X线诊断的敏感性为96.2%,特异性为16.7%,CT的诊断敏感性与特异性分别为96.8%和100.0%.两种检查方法 诊断的敏感性均较高,对比无明显差异.但是CT诊断的特异性明显高于X线诊断(P<0.05).结论 成软骨细胞瘤的X线诊断与CT诊断各具优势,但是CT诊断的特异性更好,在临床应用中两者相结合能够提供更多的诊断信息,有利于本病的诊断与鉴别诊断.

  7. Whole-body FDG PET/CT is more accurate than conventional imaging for staging primary breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Riegger, C.; Heusner, T.A. [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf (Germany); University of Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Herrmann, J.; Hahn, S.; Lauenstein, T. [University of Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Nagarajah, J.; Bockisch, A. [University of Duisburg-Essen, Medical Faculty, Department of Nuclear Medicine, Essen (Germany); Hecktor, J.; Kuemmel, S. [University of Duisburg-Essen, Medical Faculty, Department of Gynecology and Obstetrics, Essen (Germany); Otterbach, F. [University of Duisburg-Essen, Institute of Pathology and Neuropathology, Essen (Germany); Antoch, G. [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf (Germany)

    2012-05-15

    This retrospective study aimed (1) to compare the diagnostic accuracy of whole-body FDG PET/CT for initial breast cancer staging with the accuracy of a conventional, multimodal imaging algorithm, and (2) to assess potential alteration in patient management based on the FDG PET/CT findings. Patients with primary breast cancer (106 women, mean age 57 {+-} 13 years) underwent whole-body FDG PET/CT and conventional imaging (X-ray mammography, MR mammography, chest plain radiography, bone scintigraphy and breast, axillary and liver ultrasonography). The diagnostic accuracies of FDG PET/CT and a conventional algorithm were compared. Diagnostic accuracy was assessed in terms of primary tumour detection rate, correct assessment of primary lesion focality, T stage and the detection rates for lymph node and distant metastases. Histopathology, imaging or clinical follow-up served as the standards of reference. FDG PET/CT was significantly more accurate for detecting axillary lymph node and distant metastases (p = 0.0125 and p < 0.005, respectively). No significant differences were detected for other parameters. Synchronous tumours or locoregional extraaxillary lymph node or distant metastases were detected in 14 patients (13%) solely by FDG PET/CT. Management of 15 patients (14%) was altered based on the FDG PET/CT findings, including 3 patients with axillary lymph node metastases, 5 patients with extraaxillary lymph node metastases, 4 patients with distant metastases and 3 patients with synchronous malignancies. Full-dose, intravenous contrast-enhanced FDG PET/CT was more accurate than conventional imaging for initial breast cancer staging due to the higher detection rate of metastases and synchronous tumours, although the study had several limitations including a retrospective design, a possible selection bias and a relevant false-positive rate for the detection of axillary lymph node metastases. FDG PET/CT resulted in a change of treatment in a substantial proportion of

  8. Simulated scatter performance of an inverse-geometry dedicated breast CT system.

    Science.gov (United States)

    Bhagtani, Reema; Schmidt, Taly Gilat

    2009-03-01

    The purpose of this work was to quantify the effects of scatter for inverse-geometry dedicated breast CT compared to cone-beam breast CT through simulations. The inverse geometry was previously proposed as an alternative to cone-beam acquisition for volumetric CT. The inverse geometry consists of a large-area scanned-source opposite a detector array that is smaller in the transverse direction. While the gantry rotates, the x-ray beam is rapidly sequenced through an array of positions, acquiring a truncated projection image at each position. Inverse-geometry CT (IGCT) is expected to detect less scatter than cone-beam methods because only a fraction of the object is irradiated at any time and the fast detector isolates the measurements from sequential x-ray beams. An additional scatter benefit is the increased air gap due to the inverted geometry. In this study, we modeled inverse-geometry and cone-beam dedicated breast CT systems of equivalent resolution, field of view, and photon fluence. Monte Carlo simulations generated scatter and primary projections of three cylindrical phantoms of diameters 10, 14, and 18 cm composed of 50% adipose/50% glandular tissue. The scatter-to-primary ratio (SPR) was calculated for each breast diameter. Monte Carlo simulations were combined with analytical simulations to generate inverse-geometry and cone-beam images of breast phantoms embedded with tumors. Noise reprehenting the photon fluence of a realistic breast CT scan was added to the simulated projections. Cone-beam data were reconstructed with and without an ideal scatter correction. The CNR between breast tumor and background was compared for the inverse and cone-beam geometries for the three phantom diameters. Results demonstrated an order of magnitude reduction in SPR for the IGCT system compared to the cone-beam system. For example, the peak IGCT SPRs were 0.05 and 0.09 for the 14 and 18 cm phantoms, respectively, compared to 0.42 and 1 for the cone-beam system. For both

  9. Usefulness of SPECT/CT in the Diagnosis of Intrathoracic Goiter versus Metastases From Cancer of the Breast

    DEFF Research Database (Denmark)

    Dümcke, Christine Elisabeth; Madsen, Jan Lysgård

    2007-01-01

    A 77-year-old woman was referred because of local reoccurrence of cancer of the breast. Chest x-ray showed a mediastinal tumor with dislocation of the trachea to the right. A Tc-99m pertechnetate scan showed irregular tracer uptake in an enlarged left lobe of the thyroid gland. Ultrasound confirmed...... the diagnosis of a nodular goiter with intrathoracic growth of the left lobe. A SPECT/CT scan of the mediastinum clearly showed that the soft tissue tumor was the left lobe of the thyroid gland, and not lymphatic metastases....

  10. CT simulation in nodal positive breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Horst, E.; Schuck, A.; Moustakis, C.; Schaefer, U.; Micke, O.; Kronholz, H.L.; Willich, N. [Muenster Univ. (Germany). Dept. of Radiation Oncology

    2001-10-01

    Background: A variety of solutions are used to match tangential fields and opposed lymph node fields in irradiation of nodal positive breast cancer. The choice is depending on the technical equipment which is available and the clinical situation. The CT simulation of a non-monoisocentric technique was evaluated in terms of accuracy and reproducibility. Patients, Material and Methods: The field match parameters were adjusted virtually at CT simulation and were compared with parameters derived mathematically. The coordinate transfer from the CT simulator to the conventional simulator was analyzed in 25 consecutive patients. Results: The angles adjusted virtually for a geometrically exact coplanar field match corresponded with the angles calculated for each set-up. The mean isocenter displacement was 5.7 mm and the total uncertainty of the coordinate transfer was 6.7 mm (1 SD). Limitations in the patient set-up became obvious because of the steep arm abduction necessary to fit the 70 cm CT gantry aperture. Required modifications of the arm position and coordinate transfer errors led to a significant shift of the marked matchline of >1.0 cm in eight of 25 patients (32%). Conclusion: The virtual CT simulation allows a precise and graphic definition of the field match parameters. However, modifications of the virtual set-up basically due to technical limitations were required in a total of 32% of cases, so that a hybrid technique was adapted at present that combines virtual adjustment of the ideal field alignment parameters with conventional simulation. (orig.) [German] Hintergrund: Fuer den Feldanschluss zwischen Brusttangenten und ventrodorsal opponierenden Lymphknotenfeldern bei der Bestrahlung des nodal positiven Mammakarzinoms sind verschiedene Methoden in Gebrauch, wobei fuer die Auswahl technische und klinische Gegebenheiten massgeblich sind. Die CT-Simulation einer nicht monoisozentrischen Technik wird in dieser Untersuchung hinsichtlich Genauigkeit und

  11. X线钼靶摄影与超声诊断乳腺微钙化灶的对比研究%Comparative Study of X-ray Mammography Photography and Ultrasound Diagnostic in Breast Microcalcifications

    Institute of Scientific and Technical Information of China (English)

    张敏丽; 刘东顺; 贾七英; 魏志强

    2015-01-01

    Objective:To explore the effect of X-ray mammography photography and ultrasonic diagnosis in breast microcalcifications. Method:120 cases with breast microcalcifications from February 2012 to February 2015 were selected,they were given X-ray mammography photography and ultrasonic diagnosis.The two methods of sensitivity, specificity and accuracy were compared.Result:X-ray mammography photographic and ultrasound combined use of the accuracy,specificity and sensitivity were higher than X-ray mammography and ultrasound diagnosis of photography, the difference was significant(P<0.05).The sensitivity of X-ray mammography photographic was significantly higher than that of ultrasound diagnosis,and the specificity of ultrasonic diagnostic was higher than X-ray mammography photography,the difference was significant(P<0.05).Conclusion:X-ray mammography photography has high sensitivity for the diagnosis of breast microcalcifications,and the ultrasonic diagnosis has high specificity,a combination of both can significantly improve the diagnostic accuracy rate,is worthy of clinical promotion.%目的:探究采用X线钼靶摄影和超声诊断乳腺微钙化灶的诊断效果.方法:选择笔者所在医院2012年2月-2015年2月收治的120例乳腺微钙化灶患者,均给予患者X线钼靶摄影和超声诊断.对比两种方法敏感性、特异性和准确性情况.结果:X线钼靶摄影和超声联合应用的准确性、特异性和敏感性均高于X线钼靶摄影和超声诊断,差异有统计学意义(P<0.05).X线钼靶摄影的敏感性显著高于超声诊断,而超声诊断的特异性高于X线钼靶摄影,差异有统计学意义(P<0.05).结论:对于乳腺钙化灶的诊断采用X线钼靶摄影具有较高的敏感性,而采用超声诊断具有较高的特异性,两者联合使用能够显著提高诊断准确率,值得临床推广.

  12. X-ray Pulsars

    CERN Document Server

    Walter, Roland

    2016-01-01

    X-ray pulsars shine thanks to the conversion of the gravitational energy of accreted material to X-ray radiation. The accretion rate is modulated by geometrical and hydrodynamical effects in the stellar wind of the pulsar companions and/or by instabilities in accretion discs. Wind driven flows are highly unstable close to neutron stars and responsible for X-ray variability by factors $10^3$ on time scale of hours. Disk driven flows feature slower state transitions and quasi periodic oscillations related to orbital motion and precession or resonance. On shorter time scales, and closer to the surface of the neutron star, X-ray variability is dominated by the interactions of the accreting flow with the spinning magnetosphere. When the pulsar magnetic field is large, the flow is confined in a relatively narrow accretion column, whose geometrical properties drive the observed X-ray emission. In low magnetized systems, an increasing accretion rate allows the ignition of powerful explosive thermonuclear burning at t...

  13. Anatomical analysis of turgescent and semi-dry resurrection plants: the effect of sample preparation on the sample, resolution, and image quality of X-ray micro-computed tomography (μCT).

    Science.gov (United States)

    Korte, Nikola; Porembski, Stefan

    2011-04-01

    Computer tomography has been used frequently for the 3-D visualization of plant anatomical traits but sample preparation has been widely neglected. Without any preparation smaller (i.e., up to 1 × 1 cm(2) ) turgescent or semi-dry plant samples (especially leaf samples) diminish the image quality of a scan due to gradual water loss and therefore constant movement. A suitable preparation for scans of turgescent and semi-dry plant samples with a high resolution μCT (plant sample efficiently. However, water molecules and vaseline both attenuate the X-ray beam, which decreases the image quality of scans of turgescent or semi-dry plant samples. Therefore, trade-offs between the spatial resolution, sample water content, sample size, and image quality have to be considered: larger samples have to be placed further away from the X-ray tube, which leads to a lower spatial resolution; water and preparation agents attenuate the X-ray beam, causing low-quality images which may be accompanied by motion artifacts compared to a scan of a dry sample, where no preparation is necessary.

  14. 骨样骨瘤的X线CT和MRI表现及诊断价值分析%X-ray CT and MRI manifestations of osteoid osteoma and the diagnostic value analysis.

    Institute of Scientific and Technical Information of China (English)

    师卫华; 杜小萍

    2012-01-01

    Objective To investigate the X-ray, CT and MRI manifestations of osteoid osteoma and diagnos-tic value. Methods The imaging data of 136 patients with osteoid osteoma in our hospital from February 2008 to Oc-tober 2011, confirmed by pathology, were analyzed. Results 136 patients received X-ray examination, 74.26% of which showed tumor nests. 111 patients received CT examination, all showed tumor nests. 42 patients received MRI examination, 78.57% of which showed tumor nests. The display rate of tumor nest by CT examination was significant-ly higher than that by the X-ray and MRI (P<0.05). Conclusion CT examination shows the highest rate of tumor nests, serving as the most accurate method. X-ray examination is the most widely used method, serving as an impor-tant method of examination. MRI performs poorly in displaying ossification and calcification, but excellent in soft tis-sue around. The combined use of the three methods results in greater diagnostic value.%目的 探讨骨样骨瘤的X线CT和MRI表现及诊断价值.方法 选取2008年2月至2011年10月在我院诊治并经病理学证实为骨样骨瘤的患者136例,对比分析其影像学资料.结果 136例患者均行X线检查,74.26%显示有瘤巢,行CT检查的患者111例,全部显示有瘤巢,行MRI检查的患者42例,78.57%显示有瘤巢,CT检查显示瘤巢率明显高于X线和MRI检查(P<0.05).结论 CT检查瘤巢显示率最高,是最准确的方法,X线检查使用最为广泛,是重要的检查方法,MRI对骨化和钙化的敏感度差,但对周围软组织分辨率高,可结合X线或CT检查应用于临床,三者联合,诊断价值更高.

  15. 腰椎滑脱及椎弓峡部裂的X线平片与CT诊断探讨%Study of X-ray and CT Diagnosis in Lumbar Spondylolisthesis and Spondylolysis

    Institute of Scientific and Technical Information of China (English)

    李焕贵; 谢捷颖; 林春

    2016-01-01

    Objective To investigate the diagnosis effect of X-ray and CT detection in lumbar spondylolis-thesis and spondylolysis, respectively. Methods 220 cases of patients, for lumbar spondylolisthesis or spon-dylolysis examination, were randomly selected and divided into two groups equally ( group A and group B) . Then, X-ray examination was performed on the patients in group A, while CT detection was performed on the patients in group B. Finally, the detection rates of the two diagnostic methods for lumbar spondylolisthesis and spondylolysis were compared and analyzed. Results The detection rates for lumbar spondylolisthesis of group A and group B were 95. 4% and 85. 6%, respectively. The detection rates for spondylolysis of group A and group B were 87. 9%and 96. 6% in sequence. Conclusion The detection rate of CT for spondylolysis was higher than that of X-ray examination, while the detection rate for lumbar spondylolisthesis of X-ray plain films was higher than that of CT detection.%目的:探讨腰椎滑脱和椎弓峡部裂中X线平片与CT各自的诊断作用。方法首先,随机选取220例检查腰椎滑脱与椎弓根峡部裂的患者,均分成A、B两组。然后, A组行X线平片检查, B组行CT检查。最后,比较分析两种诊断方式对于腰椎滑脱及椎弓峡部裂的检出率。结果腰椎滑脱的检出率A组为95.4%, B组为85.6%;椎弓峡部裂的检出率A组为87.9%, B组为96.6%。结论 CT检查椎弓峡部裂的检出率比X线平片的检出率高, X线平片对腰椎滑脱的检出率比CT的检出率高。

  16. X线、MRI对乳腺癌的综合诊断价值%Clinical Application Value of X-ray and MRI in the Diagnosis of Breast Carcinoma

    Institute of Scientific and Technical Information of China (English)

    郭永榜

    2015-01-01

    目的:探讨X线、MRI对乳腺癌的综合诊断价值。方法回顾性分析本院36例经病理证实的乳腺癌患者X线和MRI表现,从病灶形态学、钙化、淋巴结、皮肤及胸壁受累情况及信号特点、强化模式等方面进行分析诊断,比较两种方法在检出率、诊断准确率、病灶范围等方面的价值。结果X线检出病灶30个,检出率为83.3%,诊断确诊率为80.6%,MRI检出病灶36个,检出率为100.0%,诊断准确率为91.7%。结论乳腺X线摄影检查直观、有效,是诊断乳腺癌的首选检查方法,结合MRI可提高诊断的灵敏度和特异度。%Objective To explore the comprehensive value of X-ray mammography and MRI in diagnosing the breast cancer.Methods 36 cases of patients with breast cancer were enrol ed,both mammography and MRI scan were performed,including tumor morphology,calcification,signal characteristics, enhanced mode and Si-time curve,the values of X-ray and MRl were evaluated.Results 30 masses were found by X-ray mammogram,detection rate was 83.3%and accuracy rate of X-ray was 80.6%,36 masses were detected by MRI,detection rate was 100.0%and accuracy rate of MRl was 91.7%.Conclusion A direct and effective means to breast cancer should be based on X-ray,the molybdenum X-ray mammography is helpful in the diagnosis of breast cancer,the sensitivity and specificity combined with MRI are enhanced when compared to that of single modality.

  17. Comparative study on the application of X-ray, CT and MRI in the diagnosis of cervical spondylosis%应用X线平片、CT及MRI在颈椎病诊断中的对比研究

    Institute of Scientific and Technical Information of China (English)

    任蓬程

    2013-01-01

    目的:探讨X线平片、CT、MRI检查在颈椎病诊断中的作用。方法选取2011年9月~2013年5月我院收治的颈椎病患者57例,所有患者皆进行X线平片、CT、MRI检查。结果对颈椎病的原因分析,MRI对钩突增生、颈椎曲度异常、椎间隙狭窄的诊断率高,显著高于其他两种方法,差异有统计学意义(P<0.05)。而CT对钩突增生、小关节突增生、椎体后缘骨赘形成、骨性椎管狭窄的诊断率高于X线平片(P<0.05)。而对颈椎曲度异常、椎间隙狭窄诊断率低于X线平片(P<0.05)。X线平片可以观察到颈椎双边征及椎间孔狭窄。而MRI则对纤维性椎管狭窄,伴脊髓水肿、变性,寰枢椎半脱位有独特的征象。结论综合X线平片、CT、MRI可提高颈椎病的早期诊断和定性诊断的水平。%Objective To explore the effect of X-ray, CT and MRI in the diagnosis of cervical spondylosis. Methods 57 patients with cervical spondylosis were all collected from 2011 September to 2013 May in our hospital, who were examined with X-ray, CT and MRI examination. Results The analysis of causes for cervical spondylosis showed that the diagnosis rate of MRI on uncinate hyperplasia, cervical curvature abnormality, intervertebral space stenosisrate was significantly higher than the other two methods, the difference was statistically significan(P< 0.05). While the diagnosis rate of CT on uncinate hyperplasia, facet hypertrophy, osteophyte formation, bony canalstenosis was higher than X-ray(P < 0.05). The diagnosis rate of CT on abnormal cervical curvature and intervertebral space stenosisrate was lower than X-ray(P < 0.05). X-ray could observe bilateralsyndrome and cervical intervertebral foramen stenosis, while the MRI had unique features on fibrous canal stenosis with spinal cord edema, degeneration, atlantoaxial subluxation. Conclusion Integrated X-ray, CT and MRI can improve the early diagnosis and qualitative diagnosis

  18. The Value of X-ray Mammography in Differential Diagnosis of Breast Phyllodes Tumors and Fibroadenoma%钼靶X线在乳腺叶状肿瘤和纤维腺瘤鉴别诊断中的价值

    Institute of Scientific and Technical Information of China (English)

    杨礼睿; 陈霞

    2014-01-01

    目的:分析乳腺叶状肿瘤和纤维腺瘤的钼靶X线摄影的表现,归纳总结其钼靶X线影像特征,提高乳腺叶状肿瘤的诊断准确率。方法回顾性分析经病理证实的27例叶状肿瘤钼靶X线影像表现,并以病理证实的28例纤维腺瘤为对照。结果钼靶X线表现肿块周边有"晕"征,在叶状肿瘤与纤维腺瘤中比较差异有统计学意义(P<0.05)。结论肿块周边有"晕"征在乳腺叶状肿瘤和纤维腺瘤鉴别诊断中有诊断意义。%Objectives: To analyze the X-ray mammography breast phyl ode tumor and breast fibroadenoma of the performance,to sum up the molybdenum target X-ray imaging features,to improve the accuracy of diagnosis of phyl odes tumors of the breast. Methods A retrospective analysis was made of 27 cases of phyl odes tumor of molybdenum target X-ray manifestations and pathology,and 28 cases of fibroadenoma confirmed by pathology were. Results The mammographic features in addition to mass surrounding a "halo" syndrome in phyl odes tumor and breast fibroadenoma,the dif erence was statistical y significant (P<0.05). Conclusion Mass surrounding a "halo"sign is of diagnostic significance in dif erential diagnosis of breast phyl ode tumor and breast fibroadenoma.

  19. {sup 18}F-FDG PET/CT for initial staging in breast cancer patients. Is there a relevant impact on treatment planning compared to conventional staging modalities?

    Energy Technology Data Exchange (ETDEWEB)

    Krammer, J.; Schnitzer, A.; Kaiser, C.G.; Buesing, K.A.; Schoenberg, S.O.; Wasser, K. [University of Heidelberg, Institute of Clinical Radiology and Nuclear Medicine, University Medical Centre Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Sperk, E. [University of Heidelberg, Department of Radiation Oncology, University Medical Centre Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Brade, J. [University of Heidelberg, Institute of Medical Statistics, Biomathematics and Data Processing, Medical Faculty Mannheim, Mannheim (Germany); Wasgindt, S.; Suetterlin, M. [University of Heidelberg, Department of Gynaecology and Obstetrics, University Medical Centre Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Sutton, E.J. [Memorial Sloan-Kettering Cancer Center, Evelyn H. Lauder Breast Center, Department of Radiology, New York, NY (United States)

    2015-08-15

    To evaluate the impact of whole-body {sup 18}F-FDG PET/CT on initial staging of breast cancer in comparison to conventional staging modalities. This study included 102 breast cancer patients, 101 patients were eligible for evaluation. Preoperative whole-body staging with PET/CT was performed in patients with clinical stage ≥ T2 tumours or positive local lymph nodes (n = 91). Postoperative PET/CT was performed in patients without these criteria but positive sentinel lymph node biopsy (n = 10). All patients underwent PET/CT and a conventional staging algorithm, which included bone scan, chest X-ray and abdominal ultrasound. PET/CT findings were compared to conventional staging and the impact on therapeutic management was evaluated. PET/CT led to an upgrade of the N or M stage in overall 19 patients (19 %) and newly identified manifestation of breast cancer in two patients (2 %). PET/CT findings caused a change in treatment of 11 patients (11 %). This is within the range of recent studies, all applying conventional inclusion criteria based on the initial T and N status. PET/CT has a relevant impact on initial staging and treatment of breast cancer when compared to conventional modalities. Further studies should assess inclusion criteria beyond the conventional T and N status, e.g. tumour grading and receptor status. (orig.)

  20. X-Ray Protection

    Science.gov (United States)

    1955-01-01

    15,000. • When developed In Kodak liquid X-ray developer for 5 min at a temperature of 200 C. b Film sensitivities vary with photon energy by the...for example temporomandibular -joint exposures where a skin dose of 25 r or more may be obtained during a single exposure with 65 kvp, 1.5 mm aluminum...communication. W. J. Updegrave, Temporomandibular articulation-X-ray examina- tion, Dental Radiography and Photography 26, No. 3, 41 (1953). H. 0. Wyckoff, R. J

  1. Dictionary learning based denoising of low-dose X-ray CT image%基于字典学习的低剂量X-ray CT图像去噪

    Institute of Scientific and Technical Information of China (English)

    朱永成; 陈阳; 罗立民; Toumoulin Christine

    2012-01-01

    介绍了一种基于字典学习的去噪方法,并将其应用于降低低剂量CT图像噪声水平的研究.针对体模图像和病人图像,分别选择低剂量CT图像和正常剂量CT图像作为训练样本,采用K-SVD算法,通过迭代学习构建图像字典;然后,结合正交匹配跟踪算法,实现图像稀疏表示,稀疏成分对应于图像的有用信息,其他成分对应于图像噪声;最后,依据图像的稀疏成分重建图像,达到去除噪声的目的.实验结果表明:字典的大小、稀疏表示的约束条件等参数会显著影响所提算法的去噪结果;相比低剂量CT图像,将正常剂量CT图像作为训练样本可以得到更好的去噪结果;在相同的噪声水平下,所提算法与传统图像去噪算法相比可以更好地去除图像噪声,且保留了图像的细节信息.%A dictionary learning based denoising method is introduced to eliminate the noise in low-dose computed-tomography (LDCT) image. Aiming at the phantom and patient images, the &-means singular value decomposition (K-SVD) algorithm is adopted to train image dictionary itera-tively based on LDCT and normal-dose CT (NDCT) images. Then, based on the orthogonal matching pursuit algorithm, the sparse representation decomposes the noise image into sparse component which is related to image information and remains which are regarded as noise. Finally, noises can be suppressed by reconstructing image only with its sparse components. The experimental results show that the performance of the proposed method is strongly affected by the dictionary size and the constraints for sparsity in dictionary training. The better performance can be achieved when training samples are extracted from NDCT image instead of LDCT image. Under the same noise level, compared with the traditional de-noising methods, the proposed method is more effective in suppressing noise and improving the visual effect while maintaining more diagnostic image details.

  2. Preoperative PET/CT in early-stage breast cancer

    DEFF Research Database (Denmark)

    Bernsdorf, M; Berthelsen, A K; Wielenga, V T;

    2012-01-01

    The aim of this study was to assess the diagnostic and therapeutic impact of preoperative positron emission tomography and computed tomography (PET/CT) in the initial staging of patients with early-stage breast cancer.......The aim of this study was to assess the diagnostic and therapeutic impact of preoperative positron emission tomography and computed tomography (PET/CT) in the initial staging of patients with early-stage breast cancer....

  3. X-ray and CT findings of soft tissue and bone infections secondary to acquired immunodeficiency syndrome%艾滋病并发软组织骨骼感染的X线和CT表现

    Institute of Scientific and Technical Information of China (English)

    江松峰; 刘晋新; 陈碧华; 张烈光; 甘清鑫; 黄德扬

    2011-01-01

    Objective To summarize X-ray and CT findings of soft tissue and bone infections secondary to acquired immunodeficiency syndrome (AIDS).Methods The data of X-ray and CT findings of soft tissue and bone infections in 18 patients with AIDS were retrospectively collected and analyzed.Results Of 18 patients with AIDS,the CT features of soft tissue demonstrated that subcutaneous patchy high density in 1 case which considered as cellulitis,round low density lesions with ring enhancement in 6 cases which considered as soft tissue abscesses,heterogeneous density lesions with peripheral enhancement in 1 case which considered as pyomyositis.Of 18 patients with AIDS,septic arthritis was found in 4 cases involving knee lesion in 3 cases and hip lesion.In the 4 case,the X-ray films showed bony destruction in 2 cases and the CT showed bone destruction in 3 cases and arthroedema in 4 cases.Of 18 patients with AIDS,osteomyelitis was found in 9 cases of which tuberculosis was considered in 8 cases and vertebral involvement in 6 cases.In the 9 cases,the X-ray films and CT displayed bony destruction,hyperostosis,small sequestra,and intervertebral space narrowing.Of 18 patients with AIDS,costal lesions were found in 3 cases in which the CT showed expandable bony destruction.Of 18 patients with AIDS,ilium and cacroihac joint lesions were found in 1 case in which the X-ray films and CT showed bony destruction,sequestra,and joint widening.Of 18 patients with AIDS,chronic pyogenic osteomyelitis of femur was found in 1 case in which the X-ray films showed bony destruction,hyperostosis osteosclerosis,and periosteal reaction.Conclusion The X-ray and CT features of soft tissue and bone infections secondary to AIDS are characterized.The X-ray and CT are useful tools to early diagnose soft tissue and bone infections secondary to AIDS.%目的 探讨艾滋病(AIDS)并发软组织骨骼感染的X线和CT表现.方法 回顾性分析18例AIDS并发软组织骨骼感染的X线和CT表现.结果 18

  4. 数字钼靶X线摄影结合触诊在乳腺病变诊断中的价值%Diagnostic value of digital mammography X-ray and palpation in breast lesions

    Institute of Scientific and Technical Information of China (English)

    彭晓澜; 郑青霞

    2011-01-01

    Objective To discuss the diagnostic value of mammography X-ray and palpation in benign and malignant lesions of breast. Methods One hundred and twelve breast lesions comfirmed by operations and pathological diagnosis during June 2008 to 2010 were collected, and the mammography X-ray performance in benign and malignant lesions of breast were retropectly analyed. Results The mammography X-ray performance could be taken as a reference to the qualitative diagnosis of benign and malignant lesions. Palpation was simple and had more intuitive and comprehensive understanding for patients. Conclusion Mammography X-ray performance and palpating in benign and malignant lesions qualitative diagnosis plays a complementary roles.%目的 探讨数字钼靶X线摄影结合触诊在乳腺病变的定性诊断价值.方法 收集2008-2010-06经手术和病理证实的112个乳腺病变资料,对钼靶X线诊断及触诊检查的良恶性病变进行回顾性分析.结果 钼靶X线表现可作为乳腺病变良恶性定性诊断的有效的检查手段,触诊检查简单易行,对患者有一个更直观和全面的认识.结论 钼靶X线表现及触诊在良恶性病变的定性诊断中起着互补的作用.

  5. Appearances and Diagnostic Value of X-ray,CT and MR Imaging in Osteoid Osteoma%骨样骨瘤的X线、CT和MRI表现和诊断价值

    Institute of Scientific and Technical Information of China (English)

    丁晓毅; 陆勇; 江浩; 张华; 吴达明; 何国祥

    2001-01-01

    目的:分析骨样骨瘤的X线、CT和MRI表现,评价它们的诊断价值。方法:经手术病理证实,同时有X线、CT和MRI检查的骨样骨瘤22例,其中男19例,女3例。分析X线、CT和MRI对瘤巢和瘤巢周围改变的显示能力。结果:X线、CT和MRI分别有17、22和20例表现为有一圆形或卵圆形小于2 cm的瘤巢,瘤巢周围可有程度不一的骨质硬化、骨膜反应、软组织及骨髓腔水肿或相邻关节的肿胀。X线诊断的准确率为77.3%(17/22);CT诊断的准确率为100%(22/22);MR诊断的准确率为90.9%(20/22)。结论:大多数的骨样骨瘤具有较典型的影像学表现,易于诊断,其中以CT对瘤巢的定位最为准确,单凭X线或MR的表现可因未能显示瘤巢而误、漏诊。%Objective:To analysis the appearances and to evaluate the diagnostic value of X-ray CT and MR imaging in osteoid osteoma.Methods:22 cases 19 females and 3 males of osteoid osteoma proved by surgical pathology and their X-ray,CT and MRI were reviewed.The ability of X-ray,CT and MRI to demonstrate the nidus and surrounding reaction were analyzed.Results:The nidus were appeared as round or oval shape and the diameter was less than 2 cm.It was fomd in 17 cases of X-ray film,22 CT and 20 of MRI .There were different degree of bone sclerosis,periosteal reaction and soft tissues or bone marrow edema around the nidus.The diagnostic accuracy was 77.3% for X-ray,100% for CT and 90.9% for MRI.Conclusion:Most of osteoid osteoma have the typical appearances and is no difficult to make diagnosis.CT scan is the most accuracy method to demonstrate the nidus.It is possible to make misdiagnosis only with X-ray or MRI for the case that the hidus not be demonstodted.

  6. X-Ray Psoralen Activated Cancer Therapy (X-PACT).

    Science.gov (United States)

    Oldham, Mark; Yoon, Paul; Fathi, Zak; Beyer, Wayne F; Adamson, Justus; Liu, Leihua; Alcorta, David; Xia, Wenle; Osada, Takuya; Liu, Congxiao; Yang, Xiao Y; Dodd, Rebecca D; Herndon, James E; Meng, Boyu; Kirsch, David G; Lyerly, H Kim; Dewhirst, Mark W; Fecci, Peter; Walder, Harold; Spector, Neil L

    2016-01-01

    This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of solid cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with current application to proliferative disease and extracorporeal photopheresis (ECP) of cutaneous T Cell Lymphoma. An immunogenic role for light-activated psoralen has been reported, contributing to long-term clinical responses. Psoralen therapies have to-date been limited to superficial or extracorporeal scenarios due to the requirement for psoralen activation by UVA light, which has limited penetration in tissue. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and re-radiate (phosphoresce) at UV wavelengths. The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry in combination with complimentary assays, and the in-vivo mouse study. In an in-vitro study, we show that X-PACT induces significant tumor cell apoptosis and cytotoxicity, unlike psoralen or phosphor alone (pPACT than with saline or AMT + X-ray (pPACT, and provide a foundation and rationale for future studies. In summary, X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation are delivered to a specific tumor site to generate UVA light which in-turn unleashes both short- and potentially long-term antitumor activity of photo-active therapeutics like psoralen.

  7. Application of digital mammography X-ray photography in clinical diagnosis of breast tumor%数字化钼靶 X线摄影在乳腺肿瘤临床诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    徐艳红

    2014-01-01

    目前乳腺癌已居我国女性恶性肿瘤首位,早期发现、早期诊断和早期治疗是改善乳腺癌患者预后的重要手段,而数字化钼靶X线摄影被公认为是乳腺癌影像检查的首选方法。该文旨在通过研究乳腺癌的发病趋势及早期诊断的重要性,进而讨论数字化乳腺钼靶X线摄影在乳腺癌诊断中的优势、X线影像表现、临床应用效果、钼靶X线诊断的仪器与检查方法、分类及研究进展,以提高其在乳腺肿瘤临床早期诊断中的价值。%Breast cancer has become the leading female malignancy in China; therefore , early detection , diagnosis and treatment are important means to improve the prognosis of breast cancer .Digital mammography X-ray photography is considered as the preferred method for imaging inspection of breast cancer .The paper aims to discuss the trend of breast cancer incidence and importance of early diagnosis of the disease , and improve the value of digital mammography X-ray in early clinical diagnosis of breast cancer by exploring the superiority of the technique , X-ray imaging manifestations , imaging findings , clinical application results , molybdenum target apparatus and inspection methods , classification and research progress .

  8. An analysis of mammography X-ray signs in patients with breast fibroadenomas%乳腺纤维腺瘤乳腺钼靶X射线征象分析

    Institute of Scientific and Technical Information of China (English)

    邵婉仪; 葛宇曦; 邵琳; 李晓红; 王子; 陆黎; 延根

    2016-01-01

    Objective To analyze the characteristics of mammography X-ray signs in the patients with breast fibroadenomas.Methods Mammography X-ray images of 200 patients with breast fibroadenomas were retrosepctively analyzed with imaging reporting and data system.Results Breast fibroadenomas occured in 152 cases(76 %) with compacted type and large glandular type of the breast.Breast fibroadenomas located in the upper outer quadrant in 116 cases (58%).Breast fibroadenomas displayed as lump or lump with calcification in 148 cases (74%),pure calcification in 17 cases,asymmetrical dense glandular in 26 cases,and no abnormal findings in 9 cases on mammography X-ray images.Conclusion In the analysis of mammography X-ray signs in the patients with breast fibroadenomas,attention should be paid to evaluating the calcification and asymmetrical dense glandular signs.%目的 分析乳腺纤维腺瘤乳腺钼靶X射线征象特征.方法 回顾性分析200例乳腺纤维腺瘤患者的乳腺钼靶X射线图,采用乳腺影像报告和数据系统4级分析X射线征象.结果 乳腺纤维腺瘤发生于致密型和多量腺体型乳腺者152例(76%);发病部位位于外上象限者116例(58%).以肿块或肿块合并钙化出现者148例(74%),单纯钙化17例,不对称致密腺体26例,9例未见乳腺钼靶X射线异常表现.结论 分析乳腺纤维腺瘤钼靶X射线征象时,也应重视单纯钙化和不对称致密腺体的X射线征象.

  9. Application value of molybdenum target X-ray examination in diagnosis of breast cancer%钼靶X线检查在乳腺癌诊断中的应用价值

    Institute of Scientific and Technical Information of China (English)

    王悦

    2015-01-01

    目的:探讨乳腺癌诊断中应用钼靶X线检查的价值,提高乳腺癌的早期诊断率。方法回顾性分析经手术病理确诊的66例乳腺癌患者的临床及钼靶X线检查影像资料。结果66例乳腺癌患者钼靶X线片大部分有较敏感的显影及直接征象和间接征象,均行乳腺癌根治术或改良根治术,钼靶诊断与术后病理诊断符合率为100%。结论钼靶X线检查可以大大提高乳腺癌的诊断准确率,对乳腺癌的早期明确诊断具有重要的意义,可作为早期乳腺癌诊断的首选方法。%Objective To explore the application value of molybdenum target X-ray examination in diagnosis of breast cancer, so as to improve the early diagnosis rate of breast cancer.Methods The clinical and molybdenum target X-ray examination imaging data of 66 breast cancer patients were retrospectively analyzed. Results There were sensitive and direct and indirect signs in most of the molybdenum target X-ray imaging in 66 breast cancer cases. All the cases received radical mastectomy or improved mastectomy. The coincidence rate of molybdenum target diagnosis and postoperative pathological diagnosis was 100%.Conclusion Molybdenum target X-ray examination can remarkably improve the accuracy rate of breast cancer diagnosis, and it has important value for early diagnosis of breast cancer. This method can be use as the primary method in early diagnosis of breast cancer.

  10. A novel high-pressure vessel for simultaneous observations of seismic velocity and in situ CO2 distribution in a porous rock using a medical X-ray CT scanner

    Science.gov (United States)

    Jiang, Lanlan; Nishizawa, Osamu; Zhang, Yi; Park, Hyuck; Xue, Ziqiu

    2016-12-01

    Understanding the relationship between seismic wave velocity or attenuation and CO2 saturation is essential for CO2 storage in deep saline formations. In the present study, we describe a novel upright high-pressure vessel that is designed to keep a rock sample under reservoir conditions and simultaneously image the entire sample using a medical X-ray CT scanner. The pressure vessel is composed of low X-ray absorption materials: a carbon-fibre-enhanced polyetheretherketone (PEEK) cylinder and PEEK vessel closures supported by carbon-fibre-reinforced plastic (CFRP) joists. The temperature was controlled by a carbon-coated film heater and an aramid fibre thermal insulator. The assembled sample cell allows us to obtain high-resolution images of rock samples during CO2 drainage and brine imbibition under reservoir conditions. The rock sample was oriented vertical to the rotation axis of the CT scanner, and seismic wave paths were aligned parallel to the rotation axis to avoid shadows from the acoustic transducers. The reconstructed CO2 distribution images allow us to calculate the CO2 saturation in the first Fresnel zone along the ray path between transducers. A robust relationship between the seismic wave velocity or attenuation and the CO2 saturation in porous rock was obtained from experiments using this pressure vessel.

  11. Dedicated breast CT: effect of adaptive filtration on dose distribution

    CERN Document Server

    Shikhaliev, Polad M

    2016-01-01

    Purpose: The purpose of the work was experimental investigations of the breast dose distributions with adaptive filtration. Adaptive filtration reduces detector dynamic range and improves image quality. The adaptive filter with predetermined shape is placed at the x-ray beam such that the x-ray intensity at the detector surface is flat. However, adaptive filter alters the mean dose to the breast, as well as volume distribution of the dose. Methods: The dose was measured using a 14 cm diameter cylindrical acrylic breast phantom. An acrylic adaptive filter was fabricated to match the 14 cm diameter of the phantom. The dose was measured using ion chamber inserted into holes distributed along the radius of the phantom from the center to the edge. The radial distribution of dose was measured and fitted by an analytical function and the volume distribution and mean value of dose was calculated. The measurements were performed at 40, 60, 90, and 120 kVp tube voltages and 6.6 mGy air kerma. Results: The adaptive filt...

  12. Characterizing a discrete-to-discrete X-ray transform for iterative image reconstruction with limited angular-range scanning in CT

    DEFF Research Database (Denmark)

    Sidky, Emil; Jørgensen, Jakob Heide; Pan, Xiaochuan

    2012-01-01

    Iterative image reconstruction in computed tomography often employs a discrete-to-discrete (DD) linear data model, and many of the aspects of the image recovery relate directly to the properties of this linear model. While much is known about the properties of the continuous X-ray, the correspond......Iterative image reconstruction in computed tomography often employs a discrete-to-discrete (DD) linear data model, and many of the aspects of the image recovery relate directly to the properties of this linear model. While much is known about the properties of the continuous X...

  13. Imaging of metastatic lymph nodes by X-ray phase-contrast micro-tomography.

    Directory of Open Access Journals (Sweden)

    Torben Haugaard Jensen

    Full Text Available Invasive cancer causes a change in density in the affected tissue, which can be visualized by x-ray phase-contrast tomography. However, the diagnostic value of this method has so far not been investigated in detail. Therefore, the purpose of this study was, in a blinded manner, to investigate whether malignancy could be revealed by non-invasive x-ray phase-contrast tomography in lymph nodes from breast cancer patients. Seventeen formalin-fixed paraffin-embedded lymph nodes from 10 female patients (age range 37-83 years diagnosed with invasive ductal carcinomas were analyzed by X-ray phase-contrast tomography. Ten lymph nodes had metastatic deposits and 7 were benign. The phase-contrast images were analyzed according to standards for conventional CT images looking for characteristics usually only visible by pathological examinations. Histopathology was used as reference. The result of this study was that the diagnostic sensitivity of the image analysis for detecting malignancy was 100% and the specificity was 87%. The positive predictive value was 91% for detecting malignancy and the negative predictive value was 100%. We conclude that x-ray phase-contrast imaging can accurately detect density variations to obtain information regarding lymph node involvement previously inaccessible with standard absorption x-ray imaging.

  14. A minimum spanning forest based classification method for dedicated breast CT images

    NARCIS (Netherlands)

    Pike, R.; Sechopoulos, I.; Fei, B.

    2015-01-01

    PURPOSE: To develop and test an automated algorithm to classify different types of tissue in dedicated breast CT images. METHODS: Images of a single breast of five different patients were acquired with a dedicated breast CT clinical prototype. The breast CT images were processed by a multiscale bila

  15. 彩色多普勒超声与钼靶X线诊断乳腺癌的对比分析%A comparative analysis of color Doppler ultrasound and mammography x-ray in diagnosis of breast cancer

    Institute of Scientific and Technical Information of China (English)

    刘欣娉; 时伟; 武林松

    2015-01-01

    Objective To discuss the advantages and value of color Doppler ultrasound and X-ray mammography in the diagnosis of breast cancer. Methods Thirty-eight cases of breast cancer pathologically confirmed in our hospital were retrospectively analyzed,and the diagnostic results of ultrasound and molybdenum target X-ray were compared. Results 34 cases were detected in breast ultrasound group, and 4 cases missed;32 cases were detected in mammography X-ray group of breast cancer,and 6 cases missed. Ultrasound group showed a higher rate of mass than mammography X-ray group,and there was no significant difference between the two groups(P>0. 05). There was no significant difference in tumor size and the detection rate of edge levy burr between the two groups(P>0. 05). The blood vessels and lymph node detection rate in ultrasound group was significantly higher than that of mammography X-ray group,microcalcifications detection rate in mammography X-ray group was significantly higher than that in ultrasound group,and the difference was statistically significant(P<0. 05). Conclusion Ultrasound and mammography X-ray play an important role in the diagnosis of breast cancer,and both have their own advanta-ges. If organically combined,they will significantly improve the accuracy of the diagnosis of breast cancer.%目的:探讨彩色多普勒超声及乳腺钼靶X线在乳腺癌诊断中的优势和价值。方法对经术后病理证实的38例乳腺癌患者进行回顾性分析,比较彩超和钼靶X线的诊断结果。结果彩超组检出乳腺癌34例,漏诊4例;钼靶X线组检出乳腺癌32例,漏诊6例,彩超组对肿块的显示率高于钼靶X线组,两组比较差异无统计学意义(P>0.05);对肿块大小、边缘毛刺征的检出率比较,两组比较差异无统计学意义(P>0.05);彩超组对血管和淋巴结的检出率明显高于钼靶X线组,钼靶X线组对微钙化的检出率明显高于彩超组,差

  16. ~(99m)Tc-奥曲肽显像和X线钼靶诊断乳腺癌%~(99m)Tc-octreotide scintigraphy and planar X-ray mammography diagnosis of breast cancer

    Institute of Scientific and Technical Information of China (English)

    何小江; 黄劲雄; 陈贵兵; 俞浩; 吴华

    2009-01-01

    目的 比较~(99m)Tc-奥曲肽显像和X线钼靶诊断乳腺癌的临床应用价值. 方法 32例临床怀疑乳腺癌的女性患者,均进行~(99m)Tc-奥曲肽显像和X线钼靶摄影,以手术病理结果为标准,比较二者对乳腺癌的诊断效能. 结果 ~(99m)Tc-奥曲肽显像和X线钼靶摄影诊断乳腺癌的灵敏度分别为91.67%、66.67%(χ~2=4.54,P<0.05),特异性分别为100%、37.50%(χ~2=4.65,P<0.05),准确性分别为93.75%、59.38%(χ~2=10.54,P<0.05),阳性预测值分别为100%、76.19%(χ~2=5.93,P<0.05),阴性预测值分别为80.00%、27.27%(χ~2=3.92,P<0.05).联合两种方法诊断的灵敏度、特异性、准确性、阳性预测值和阴性预测值分别为95.83%、100%、96.88%、82.14%和47.06%. 结论 ~(99m)Tc-奥曲肽显像对乳腺癌的诊断效能高于X线钼靶摄影,两者联合可进一步提高诊断效能.%Objective To compare the value of (~99m) Tc-octreotide scintigraphy and planar X-ray mammography in the diagnosis of breast cancer. Methods A total of 32 patients with suspected breast cancer were enrolled into this study. All patients underwent (~99m) Tc-octreotide scintigraphy and planar X-ray mammography. The diagnostic efficiency of (~99m) Tc-octreotide scintigraphy and planar X-ray mammography were compared based on the post-surgery pathology. Results The sensitivity of (~99m) Tc-octreotide scintigraphy and planar X-ray mammography in the diagnosis of breast cancer was 91.67% and 66.67%, the specificity was 100% and 37.50%, the accuracy was 93.75% and 59.38%, respectively. Combining (~99m) Tc-octreotide scintigraphy with planar X-ray mammography, the sensitivity, specificity, accuracy, positive predicting values and negative predicting values for breast cancer was 95.83%, 100%, 96.88%, 82.14% and 47.06%, respectively. Conclusion The diagnostic efficiency of (~99m) Tc-octreotide scintigraphy for breast cancer is superior to planar X-ray mammography. (~99m) Tc-octreotide scintigraphy combined with planar X-ray

  17. TV-based conjugate gradient method and discrete L-curve for few-view CT reconstruction of X-ray in vivo data

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaoli; Hofmann, Ralf; Dapp, Robin; van de Kamp, Thomas; Rolo, Tomy dos Santos; Xiao, Xianghui; Moosmann, Julian; Kashef, Jubin; Stotzka, Rainer

    2015-01-01

    High-resolution, three-dimensional (3D) imaging of soft tissues requires the solution of two inverse problems: phase retrieval and the reconstruction of the 3D image from a tomographic stack of two-dimensional (2D) projections. The number of projections per stack should be small to accommodate fast tomography of rapid processes and to constrain X-ray radiation dose to optimal levels to either increase the duration of in vivo time-lapse series at a given goal for spatial resolution and/or the conservation of structure under X-ray irradiation. In pursuing the 3D reconstruction problem in the sense of compressive sampling theory, we propose to reduce the number of projections by applying an advanced algebraic technique subject to the minimisation of the total variation (TV) in the reconstructed slice. This problem is formulated in a Lagrangian multiplier fashion with the parameter value determined by appealing to a discrete L-curve in conjunction with a conjugate gradient method. The usefulness of this reconstruction modality is demonstrated for simulated and in vivo data, the latter acquired in parallel-beam imaging experiments using synchrotron radiation. (C) 2015 Optical Society of America

  18. X-ray and CT Diagnosis in a Comparative Analysis of the Diagnosis of Spinal Fracture%X线与CT诊断在脊柱骨折诊断中的对照分析

    Institute of Scientific and Technical Information of China (English)

    李刚; 谢坪; 蒲红

    2014-01-01

    目的探讨X线与CT检查在脊柱骨折诊断中的临床价值。方法选取2010年1月~2013年1月于我院诊断为脊柱骨折的122例患者,回顾分析其资料,所有患者均行X线及CT影像学检查,且影像学资料完整。结果122例患者确诊椎体骨折214个(T129个、T1276个、L145个、L231个、L328个、其他5个),其中前柱受累31例、前中柱受累61例、三柱受累30例,在后30例三柱受累患者中伴椎管狭窄者26例(轻度7例、中度13例、重度6例),伴椎体滑脱5例。X线检查结果示单纯压缩性骨折77例,不稳定性骨折45例;CT检查结果示稳定性骨折39例,不稳定性骨折83例,两种检查诊断结果差异明显,在统计学上有意义(<0.05)。结论在脊柱骨折诊断中,CT检查较X线的诊断价值更高,但仍需与X线检查相结合,提高对患者病情判断的准确性,以便正确指导临床治疗。%Objective To investigate the clinical value of X-ray and CT examinations in the diagnosis of spinal fractures. Methods Chosen 122 cases of patients diagnosed as spinal fractures in our hospital between January 2013 and January 2010, reviewed and analyzed the data, al patients were performed of X-ray and CT imaging examination, and imaging data was integrity. Results 122 patients were diagnosed of 214 vertebral body fracture (29 of T11, 76 of T12, 45 of L1, 31 of L2, 28 of L3, and five of others), including anterior column involvement in 31 cases, former column involvement in 61 cases, three column involvement, 26 cases of patients were with stenosis of 26 patients in the 30 cases of three column involvement (13 cases of mild, 7 cases of moderate, 6 cases of severe), 5 cases with vertebral slippage. The results of X-ray shows 77 cases of pure compression fractures, 45 cases of unstable fracture; CT findings shows 39 cases of fracture stability, 83 cases of unstable fractures, the results of two dif erent inspection diagnosis were significant

  19. X-Ray Astronomy

    Science.gov (United States)

    Wu, S. T.

    2000-01-01

    Dr. S. N. Zhang has lead a seven member group (Dr. Yuxin Feng, Mr. XuejunSun, Mr. Yongzhong Chen, Mr. Jun Lin, Mr. Yangsen Yao, and Ms. Xiaoling Zhang). This group has carried out the following activities: continued data analysis from space astrophysical missions CGRO, RXTE, ASCA and Chandra. Significant scientific results have been produced as results of their work. They discovered the three-layered accretion disk structure around black holes in X-ray binaries; their paper on this discovery is to appear in the prestigious Science magazine. They have also developed a new method for energy spectral analysis of black hole X-ray binaries; four papers on this topics were presented at the most recent Atlanta AAS meeting. They have also carried Monte-Carlo simulations of X-ray detectors, in support to the hardware development efforts at Marshall Space Flight Center (MSFC). These computation-intensive simulations have been carried out entirely on the computers at UAH. They have also carried out extensive simulations for astrophysical applications, taking advantage of the Monte-Carlo simulation codes developed previously at MSFC and further improved at UAH for detector simulations. One refereed paper and one contribution to conference proceedings have been resulted from this effort.

  20. X-ray Compton line scan tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kupsch, Andreas; Lange, Axel; Jaenisch, Gerd-Ruediger [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany). Fachgruppe 8.5 - Mikro-ZfP; Hentschel, Manfred P. [Technische Univ. Berlin (Germany); Kardjilov, Nikolay; Markoetter, Henning; Hilger, Andre; Manke, Ingo [Helmholtz-Zentrum Berlin (HZB) (Germany); Toetzke, Christian [Potsdam Univ. (Germany)

    2015-07-01

    The potentials of incoherent X-ray scattering (Compton) computed tomography (CT) are investigated. The imaging of materials of very different atomic number or density at once is generally a perpetual challenge for X-ray tomography or radiography. In a basic laboratory set-up for simultaneous perpendicular Compton scattering and direct beam attenuation tomography are conducted by single channel photon counting line scans. This results in asymmetric distortions of the projection profiles of the scattering CT data set. In a first approach, corrections of Compton scattering data by taking advantage of rotational symmetry yield tomograms without major geometric artefacts. A cylindrical sample composed of PE, PA, PVC, glass and wood demonstrates similar Compton contrast for all the substances, while the conventional absorption tomogram only reveals the two high order materials. Comparison to neutron tomography reveals astonishing similarities except for the glass component (without hydrogen). Therefore, Compton CT offers the potential to replace neutron tomography, which requires much more efforts.

  1. Comparison of the lung X-ray and CT imaging features of patients with cardiogenic pulmonary edema%心源性肺水肿的X线与CT对比研究

    Institute of Scientific and Technical Information of China (English)

    王增状; 姜领; 鞠衍松; 谢新刚; 黄福存; 赵仲愉; 林少华

    2014-01-01

    目的 分析心源性肺水肿患者的肺部X线与CT影像学表现,从而提高心源性肺水肿患者的诊断准确率.方法 自2010年1月至2013年1月共收治100例心源性肺水肿患者,均于发病24h内分别对患者行肺部X线与CT检查,对比分析其影像学表现.结果 急性心源性肺水肿X线表现以肺泡性肺水肿为主,X线表现与肺部CT影像学表现相似,为腺泡结节、斑片状及大片融合影,有时可见空气支气管像,病变边缘模糊.病变进展时双肺出现广泛的密度均匀实变阴影,典型者出现“蝶翼征”.病变征象检出率,二者比较差异无统计学意义.慢性心源性肺水肿多表现为间质性肺水肿,肺部X线与CT影像学表现以肺血重新分布,肺野透光度降低,肺纹理增多、增重,小叶间隔线增厚如胸膜下线、克氏线出现以及肺实质磨玻璃样变等间质性肺水肿改变为主,病变征象检查率、肺部CT征象分辨率较高,二者比较差异有统计学意义(P<0.05).结论 急性心源性肺水肿的肺部X线与CT征象表现相似,临床诊断率相当,而慢性心源性肺水肿的肺部CT检查能提供更多的诊断信息,提高临床诊断率.%Objective To analyze the lung X-ray and CT imaging features of patients with cardiogenic pulmonary edema,thereby enhancing the diagnostic accuracy in patients with the cardiogenic pulmonary edema.Methods From January 2010 to January 2013,100 patients with cardiogenic pulmonary edema were selected,all patients underwent the lung X-ray and CT examinations within 24 hours of onset,and then comparative analysis of the imaging manifestations was made.Results Acute cardiogenic pulmonary edema X-ray showed pulmonary edema with alveolar master,X-ray and CT imaging had some similar performances and manifested as acinar nodules,patchy and large fusion shadow,sometimes visible as air bronchial lesion,edge blurred.There was extensive consolidation of uniform density shadow when lung lesions

  2. Bone diagnosis by X-ray techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I. [Nuclear Engineering Program/COPPE/UFRJ, P.O. Box 68509, Av. Horacio Macedo, 2030, Sala I-133, Cidade Universitaria, Zip Code: 21941-972 Rio de Janeiro, RJ (Brazil)], E-mail: inaya@lin.ufrj.br; Anjos, M.J. [Nuclear Engineering Program/COPPE/UFRJ, P.O. Box 68509, Av. Horacio Macedo, 2030, Sala I-133, Cidade Universitaria, Zip Code: 21941-972 Rio de Janeiro, RJ (Brazil); Physics Institute, UERJ (Brazil); Farias, M.L.F. [University Hospital, UFRJ (Brazil); Parcegoni, N.; Rosenthal, D. [Biophysics Institute, UFRJ (Brazil); Duarte, M.E.L. [Histologic and Embriology Department, UFRJ (Brazil); Lopes, R.T. [Nuclear Engineering Program/COPPE/UFRJ, P.O. Box 68509, Av. Horacio Macedo, 2030, Sala I-133, Cidade Universitaria, Zip Code: 21941-972 Rio de Janeiro, RJ (Brazil)

    2008-12-15

    In this work, two X-ray techniques used were 3D microcomputed tomography (micro-CT) and X-ray microfluorescence (micro-XRF) in order to investigate the internal structure of the bone samples. Those two techniques work together, e.g. as a complement to each other, to characterize bones structure and composition. Initially, the specimens were used to do the scan procedure in the microcomputer tomography system and the second step consists of doing the X-ray microfluorescence analysis. The results show that both techniques are powerful methods for analyzing, inspecting and characterizing bone samples: they are alternative procedures for examining bone structures and compositions and they are complementary.

  3. Achieving high-resolution soft-tissue imaging with cone-beam CT: a two-pronged approach for modulation of x-ray fluence and detector gain

    Science.gov (United States)

    Graham, S. A.; Siewerdsen, J. H.; Moseley, D. J.; Keller, H.; Shkumat, N. A.; Jaffray, D. A.

    2005-04-01

    Cone-beam computed tomography (CBCT) presents a highly promising and challenging advanced application of flat-panel detectors (FPDs). The great advantage of this adaptable technology is in the potential for sub-mm 3D spatial resolution in combination with soft-tissue detectability. While the former is achieved naturally by CBCT systems incorporating modern FPD designs (e.g., 200 - 400 um pixel pitch), the latter presents a significant challenge due to limitations in FPD dynamic range, large field of view, and elevated levels of x-ray scatter in typical CBCT configurations. We are investigating a two-pronged strategy to maximizing soft-tissue detectability in CBCT: 1) front-end solutions, including novel beam modulation designs (viz., spatially varying compensators) that alleviate detector dynamic range requirements, reduce x-ray scatter, and better distribute imaging dose in a manner suited to soft-tissue visualization throughout the field of view; and 2) back-end solutions, including implementation of an advanced FPD design (Varian PaxScan 4030CB) that features dual-gain and dynamic gain switching that effectively extends detector dynamic range to 18 bits. These strategies are explored quantitatively on CBCT imaging platforms developed in our laboratory, including a dedicated CBCT bench and a mobile isocentric C-arm (Siemens PowerMobil). Pre-clinical evaluation of improved soft-tissue visibility was carried out in phantom and patient imaging with the C-arm device. Incorporation of these strategies begin to reveal the full potential of CBCT for soft-tissue visualization, an essential step in realizing broad utility of this adaptable technology for diagnostic and image-guided procedures.

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... and Media Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to X-ray ( ...

  5. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very small dose ... to produce pictures of the inside of the abdominal cavity. It is used to evaluate the stomach, liver, ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... radiation like light or radio waves. X-rays pass through most objects, including the body. Once it ... organs, allow more of the x-rays to pass through them. As a result, bones appear white ...

  9. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a ... Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your privacy. Information entered here ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. A bone ... bones. top of page How should I prepare? Most bone x-rays require no special preparation. You ...

  11. Soft X-ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Seely, John

    1999-05-20

    The contents of this report cover the following: (1) design of the soft x-ray telescope; (2) fabrication and characterization of the soft x-ray telescope; and (3) experimental implementation at the OMEGA laser facility.

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? A bone x-ray is used to: ... and x-rays. top of page What does the equipment look like? The equipment typically used for ...

  13. Chest Traumatic Pulmonary Hemorrhage of X-Ray Plain Film, CT Diagnosis Analysis%胸部损伤性肺出血的X线平片、CT诊断分析

    Institute of Scientific and Technical Information of China (English)

    陆忠才

    2013-01-01

    Objective:To study the chest traumatic pulmonary hemorrhage of X-ray plain film, CT diagnosis application value. Methods:The diagnosis and treatment in our hospital of 66 cases of chest injury patients with pulmonary hemorrhage, the implement X-ray plain film and CT diagnosis, to the patient to diagnose. Results:Through to all patients in X-ray plain film and CT diagnosis, image display performance for pulmonary interstitial change have 23 cases, accounting for 34.8%, affects the performance show for lung parenchyma real variable shadow of 24 cases, accounting for 36.4%, display for traumatic pulmonary cyst of 11 cases, accounting for 16.7%, shown as the lungs hematoma of 8 cases, accounting for 12.1%. Conclusion:The chest traumatic pulmonary hemorrhage disease.%目的:探讨胸部损伤性肺出血的X线平片、CT诊断应用价值。方法:选取在我院诊治的66例胸部损伤性肺出血患者,对其实行X线平片及CT诊断,以对患者的病情进行确诊。结果:通过对所有患者实行X线平片及CT诊断,影像表现显示为肺间质性改变的有23例,占34.8%,影响表现显示为肺实质实变影的有24例,占36.4%,显示为创伤性肺囊肿的有11例,占16.7%,显示为肺内血肿的有8例,占12.1%。结论:胸部损伤性肺出血疾病。

  14. X线、CT在减压性骨坏死早期诊断中的价值%Early Diagnosis of Dysbaric Osteonecrosis with X-ray and CT

    Institute of Scientific and Technical Information of China (English)

    于成福; 杨艺; 曹子文; 李绍林

    2012-01-01

    目的 探讨X线、CT在减压性骨坏死(dysbaric osteonecrosis,DON)早期诊断中的价值.方法 随机选择66名潜水员为观察组;50名正常者为对照组.分别行双肩、双髋、双膝关节X线及CT检查,分析两种检查方法对早期DON征象的检出率.结果 观察组X线检出病灶共36个,其中单纯囊变病灶9个,单纯钙化病灶21个,钙化与囊变共存者3个.CT显示观察组病灶共119个,其中单纯囊变病灶21个,单纯钙化病灶58个,钙化与囊变共存者20个.CT显示对照组钙化病灶56个;囊变病灶0个.结论 在DON早期诊断中CT对钙化、囊变征象的检出率显著高于X线(P<0.05);囊变可作为诊断DON的早期征象;钙化虽然敏感性较高但特异性较差,因此只能作为诊断DON早期诊断的参考征象.%Objective To explore the X-ray and CT features in early stage of dysbaric osteonecrosis. Methods Sixty six divers and fifty normal people were selected as test group and control group respectively. The X-ray and CT images of bilateral shoulders, knees and hips were compared between two groups. The value of two methods in detecting early stage of dysbaric osteonecrosis were analyzed. Results In test group, the merely cystic lesions were showed in 9, calcification in 21 and both cystic and calcific lesions in 3 on X-ray images. On CT images, the cystic lesions were showed in 21, the calcification in 58, and both cystic and calcilic lesions in 20. In control group, There were 56 calcification lesions on CT images , but no cystic lesions found. Conclusion In the diagnosing early stage of dysbaric osteonecrosis, the detection rate of CT for the cystic and/or calcific lesion is higher than that of X-ray (P < 0.05). The cystic lesion is the character for early diagnosis.

  15. Chest X-Ray

    Medline Plus

    Full Text Available ... Site Index A-Z Spotlight Recently posted: Anal Cancer Facet Joint Block Video: CT of the Heart ... Therapy Video: CT of the Sinuses Video: Colorectal Cancer Screening Radiology and You Sponsored by Image/Video ...

  16. Actinomycosis of the Chest X-ray Plain Film and CT Imaging Features%胸部放线菌病的X线平片和CT影像特点研究

    Institute of Scientific and Technical Information of China (English)

    岳莉; 闫国梁

    2015-01-01

    Objective Analysis actinomycosis of the chest X-ray plain film and CT tomography imaging characteristics, the evaluation of the value of X-ray and CT in the diagnosis of the disease.Methods Choose from January 2005 to February 2015, in our hospital during the period, confirmed by laboratory tests for patients with thoracic actinomycosis 10 cases as the research object, all patients were performed X-ray plain film and CT tomography; CT images with a standard algorithm, multi plane restructuring image, image characteristics.Results This group of 10 cases with X-ray is, lateral chest plain film are displayed as mass and large dense shadow, but did not show empty, liquefied gas and lesions; CT examination results showed that 52 actinomycetes lesions involving 18 normal; 8 cases of patients with CT images show that mass as the main lesions, lung see more spots or patch around the lesions and the funicular fuzzy shadow; Mass in the thin wall, and hollow, thin wall smooth, hollow with low density liquefaction and scattered suspended gas oven shadow; CT scan showed to see gas-liquid surface; CT images of 10 cases were showed lesion adjacent pleural thickening, 8 cases of patients with lung CT images showed the door increases and/or mediastinal lymph nodes, 2 cases of right lung CT images showed patchy shadow merge mediastinal abscess.Conclusion X-ray plain film to check the chest actinomycosis cannot view demonstrates the focal area of cavity, liquid and gas, limited diagnostic value and CT tomography can display the details of the lesion, has the characteristic, has high diagnostic value.%目的:分析胸部放线菌病的X线平片和CT体层摄影术影像特点,评价X线及CT在诊断该病中的价值。方法选择2005年1月至2015年2月期间我院收治,经实验室检查证实为胸部放线菌病的患者10例为研究对象,所有患者均行X线平片和CT体层摄影术检查;CT影像采用标准算法、多平面重组图像,观

  17. Automatic Microcalcifications Pattern Recognition From X-Ray Mammographies

    Science.gov (United States)

    Magnin, Isabelle E.; El Alaoui, Mohsine; Bremond, Alain

    1989-10-01

    X-ray mammogram is the only breast cancer detection technique presently available with proven efficacy and nearly 50% of breast carcinomas demonstrate microcalcifications on mammograms. Moreover, it has been shown that clustered microcalcifications where the only sign of abnormality in about 36% of nonpalpable, clinically occult breast cancers.

  18. X-ray CT and laboratory measurements on glacial till subsoil cores – assessment of inherent and compaction-affected soil structure characteristics

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Wildenschild, Dorthe; Berisso, Feto Esimo

    2013-01-01

    porosity, effective air-filled porosity, and air permeability). Undisturbed soil cores were sampled at two depths (0.35 and 0.7 m) in a long-term soil compaction experiment in southern Sweden 14 years after its establishment. Persistence of subsoil compaction was detectable by CT-estimated soil matrix...... density, bulk density, and total porosity. Vertical distribution of CT-estimated airfilled macroporosity between 0.25- and 0.45-m depth showed that biological activity effect on macroporosity was largest in the top of the soil columns from the compacted plots, whereas reduction of macroporosity...... was significant at the bottom of the same columns. This was not detectable by classical laboratory measurements. Variations in air permeability could be related to the CT-estimated number of pores but not to the CT-estimated air-filled macroporosity. Despite using a coarse resolution, the combination...

  19. 成软骨细胞瘤应用X线与CT的临床诊断评价%Clinical Diagnostic Evaluation of Chondroblastoma with X-ray and CT Scanning

    Institute of Scientific and Technical Information of China (English)

    李爱芝

    2014-01-01

    目的:分析X线与CT扫描技术在成软骨细胞瘤应用中的临床疗效,并进行整体的比较观察。方法:选取2013年1月-2014年2月笔者所在医院收治的成软骨细胞瘤患者30例,均进行X线与CT扫描,观察两组在X线与CT扫描状态下的整体情况。结果:通过对30例患者的观察,其中,X线显示中,成软骨细胞瘤的病灶主要表现为圆形或者不规则的呈现出局限性骨破坏区,而CT显示中,病灶呈不同程度的分叶状,在边界相对清晰,呈现出半环形的钙化形式。从整个病理结果的分析来看通过病例检查,30例患者中确诊为成软骨细胞瘤的患者27例,排除3例。X线诊断呈阳性患者21例,排除9例,1例误诊为阴性,7例误诊为阳性;CT扫描诊断呈阳性患者28例,排除2例,有1例误诊呈阴性。其中,X线诊断的敏感性为96.8%(30/31),特异性为12.5%(1/8),CT诊断的敏感性与特异性也分别表现为97.4%(37/38)和100%(1/1),数据采用来源临床运用数据。但是,从诊断的特异性来看,CT诊断要明显高于X线扫描,有一定的差异性。结论:在对成软骨细胞瘤的临床诊断中,采用X线与CT扫描都具有一定的优势,其中CT扫描的特异性更加占据优势,在临床诊断中能提供更加详实的数据,有利于整个病的诊断与鉴别,具有一定的优越性。%Objective:To analyze the effect of X-ray and CT scanning technique in the clinical application of chondroblastoma,and overall comparative observation.Method:Collected from January 2013 to February 2014 in our hospital 30 cases of chondroblastoma,they were given X-ray and CT scanning,two groups were observed in the X-ray and CT scanning state of the overall situation.Result:Through the observation,30 cases,X-ray,chondroblastoma lesions mainly showed round or irregular showed limited bone destruction,CT display showed different degrees of lobulated,in the relative

  20. 乳腺彩超和X射线摄影在普查中的合理应用解析%ReasonableResolutionBreastUltrasoundandX-rayPhotographyintheCensus

    Institute of Scientific and Technical Information of China (English)

    房兆国

    2013-01-01

    Objective To study the analysis of breast ultrasound and X ray photography reasonable application method in the census and the effect. Methods A retrospective analysis of January 2008 to June 2012 year, our hospital for breast ultrasound and X-ray examination of the data from 1000 women, according to the test results of different patients were randomly divided into four groups, each group with kappa results on consistency check. Results X-ray photography and frankincense color Doppler ultrasound examination in groupⅠconsistent result is relatively poor;comparison groupⅡpatients examined consistent positive rate was signiifcant;in groupⅢcheck consistency is poor, the positive rate had a signiifcant difference;Ⅳgroup examination results have good coherence, the positive rate showed no statistical signiifcance. Conclusion Clinical breast examination, deal with solitary nodule underwent breast X examination combined with breast ultrasonography;bilateral breast symmetry of patients with hyperplasia of color Doppler ultrasound;breast ultrasound examination no abnormalities in patients with current.%  目的研究分析乳腺彩超和X射线摄影在普查中的合理应用方法和效果。方法回顾性分析2008年1月至2012年6月期间,我院对1000例女性进行乳腺彩超检查和X线检查的资料,按照检查结果不同将患者随机分为四组,采用kappa评论各组检查结果的一致性。结果Ⅰ组的X线摄影与乳香彩超检查结果一致性相对较差;Ⅱ组患者的检查一致性较好阳性率比较具有统计学意义;Ⅲ组的检查一致性差,阳性率比较差异有统计学意义;Ⅳ组的检查结果一致性很好,阳性率比较无统计学意义。结论进行乳腺临床检查时,应对孤立性结节患者行乳腺X现检查结合乳腺彩超检查;对双侧乳腺对称增生患者行彩超检查;对无异常患者现行乳腺彩超检查。

  1. The Diagnostic Value of X-ray and MRI in Breast Mucinous Adenocarcinoma%X线和MRI在乳腺黏液腺癌中的诊断价值

    Institute of Scientific and Technical Information of China (English)

    马龚宝

    2015-01-01

    目的 评价X线和MRI在乳腺黏液腺癌中的诊断价值.方法回顾分析我院2013年12月~2014年12月收治的乳腺黏液腺癌患者120例,根据不同诊断方案分为两组(各60例),对照组行X线诊断,研究组行MRI诊断,依据病理诊断结果,评价两组诊断结果.结果研究组符合率93.33%比对照组75.00%高(P<0.05).结论 对于乳腺黏液腺癌的诊断,予以MRI诊断价值较之X线更高,可建议结合两种方案,以提高诊断成功率.%Objective X-ray evaluation and diagnostic value of MRI in breast mucinous adenocarcinoma. Methods Retrospective analysis of patients with mucinous carcinoma of the breast in our hospital in December 2013 -2014 December treated 120 cases, depending on the diagnostic program is divided into two groups (60 patients) in the control group underwent X-ray diagnosis, the study group underwent MRI diagnosis, based on pathological diagnosis Results , the evaluation Results of the diagnostic groups. Results Research Group in line with the rate of 93.33% compared with the control group, 75.00% high (P < 0.05). Conclusion For the diagnosis of breast mucinous carcinoma, the diagnostic value of MRI to be higher than the X-ray, may recommend a combination of two programs to improve the diagnostic success rate.

  2. X-ray Crystallography Facility

    Science.gov (United States)

    2000-01-01

    Edward Snell, a National Research Council research fellow at NASA's Marshall Space Flight Center (MSFC), prepares a protein crystal for analysis by x-ray crystallography as part of NASA's structural biology program. The small, individual crystals are bombarded with x-rays to produce diffraction patterns, a map of the intensity of the x-rays as they reflect through the crystal.

  3. X-Ray Exam: Hip

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip A A A What's in ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that ...

  4. X-Ray Exam: Finger

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Finger KidsHealth > For Parents > X-Ray Exam: Finger A A A What's in ... español Radiografía: dedo What It Is A finger X-ray is a safe and painless test that ...

  5. X-Ray Exam: Foot

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Foot KidsHealth > For Parents > X-Ray Exam: Foot A A A What's in ... español Radiografía: pie What It Is A foot X-ray is a safe and painless test that ...

  6. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Wrist KidsHealth > For Parents > X-Ray Exam: Wrist A A A What's in ... español Radiografía: muñeca What It Is A wrist X-ray is a safe and painless test that ...

  7. X-Ray Exam: Ankle

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Ankle KidsHealth > For Parents > X-Ray Exam: Ankle A A A What's in ... español Radiografía: tobillo What It Is An ankle X-ray is a safe and painless test that ...

  8. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Pelvis KidsHealth > For Parents > X-Ray Exam: Pelvis A A A What's in ... español Radiografía: pelvis What It Is A pelvis X-ray is a safe and painless test that ...

  9. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Forearm KidsHealth > For Parents > X-Ray Exam: Forearm A A A What's in ... español Radiografía: brazo What It Is A forearm X-ray is a safe and painless test that ...

  10. X-ray selected BALQSOs

    CERN Document Server

    Page, M J; Ceballos, M; Corral, A; Ebrero, J; Esquej, P; Krumpe, M; Mateos, S; Rosen, S; Schwope, A; Streblyanska, A; Symeonidis, M; Tedds, J A; Watson, M G

    2016-01-01

    We study a sample of six X-ray selected broad absorption line (BAL) quasi-stellar objects (QSOs) from the XMM-Newton Wide Angle Survey. All six objects are classified as BALQSOs using the classic balnicity index, and together they form the largest sample of X-ray selected BALQSOs. We find evidence for absorption in the X-ray spectra of all six objects. An ionized absorption model applied to an X-ray spectral shape that would be typical for non-BAL QSOs (a power law with energy index alpha=0.98) provides acceptable fits to the X-ray spectra of all six objects. The optical to X-ray spectral indices, alpha_OX, of the X-ray selected BALQSOs, have a mean value of 1.69 +- 0.05, which is similar to that found for X-ray selected and optically selected non-BAL QSOs of similar ultraviolet luminosity. In contrast, optically-selected BALQSOs typically have much larger alpha_OX and so are characterised as being X-ray weak. The results imply that X-ray selection yields intrinsically X-ray bright BALQSOs, but their X-ray sp...

  11. Clinical Diagnostic Value of X-ray and CT in Diagnosing Ankylosing Spondylitis Sacroiliac Joint Disease%X线、CT对强直性脊柱炎骶髂关节病变诊断的临床应用价值

    Institute of Scientific and Technical Information of China (English)

    张开东; 金贤德

    2016-01-01

    Objective:To compare the diagnostic value of X-ray and CT in diagnosis of ankylosing spon-dylitis.Methods:The X-ray and CT imaging features of 57 cases of patients with ankylosing spondylitis from April 201 1 to May 2015 were retrospectively analyzed.After administration,all the patients received X-ray and CT examination,compare the diagnostic rate of ankylosing spondylitis.Results:The diagnostic levels of grade 0,grade I and grade II were improved by CT,and the difference was statistically significant (P 0.05)for the diagnosis of grade III and IV.The imaging features of X-ray and CT at the joint were both vague surface,bone erosion,bone sclerosis,joint space chan-ges and spine rigidity,but the rate of CT on the imaging findings was significantly higher than that of the plain X-ray,the difference was statistically significant(P 0.05)。X 线和 CT 在骶髂关节的影像征象均表现为关节面模糊、骨侵蚀、骨硬化、关节间隙变化和脊柱强直,但 CT 对上述影像征象发现率上明显高于普通 X 线,差异均有统计学意义(P <0.05)。结论:CT 对强直性脊柱炎骶髂关节病变的诊断价值明显优于 X 线,但 X 线检查方法简单,成本低,可做为首选的筛查方法之一。

  12. X-Ray Multimodal Tomography Using Speckle-Vector Tracking

    OpenAIRE

    Berujon, Sebastien; Ziegler, Eric

    2015-01-01

    We demonstrate computerized tomography (CT) reconstructions from absorption, phase and dark-field signals obtained from scans acquired when the x-ray probe light is modulated with speckle. Two different interlaced schemes are proposed to reduce the number of sample exposures. First, the already demonstrated x-ray speckle-vector tracking (XSVT) concept for projection imaging allows the three signal CT reconstructions from multiple images per projection. Second, a modified XSVT approach is show...

  13. High Resolution X-ray-Induced Acoustic Tomography

    Science.gov (United States)

    Xiang, Liangzhong; Tang, Shanshan; Ahmad, Moiz; Xing, Lei

    2016-05-01

    Absorption based CT imaging has been an invaluable tool in medical diagnosis, biology, and materials science. However, CT requires a large set of projection data and high radiation dose to achieve superior image quality. In this letter, we report a new imaging modality, X-ray Induced Acoustic Tomography (XACT), which takes advantages of high sensitivity to X-ray absorption and high ultrasonic resolution in a single modality. A single projection X-ray exposure is sufficient to generate acoustic signals in 3D space because the X-ray generated acoustic waves are of a spherical nature and propagate in all directions from their point of generation. We demonstrate the successful reconstruction of gold fiducial markers with a spatial resolution of about 350 μm. XACT reveals a new imaging mechanism and provides uncharted opportunities for structural determination with X-ray.

  14. X-ray today

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, U. [Philips Medical Systems, Hamburg (Germany)

    2001-09-01

    The interest attracted by the new imaging modalities tends to overshadow the continuing importance of projection radiography and fluoroscopy. Nevertheless, projection techniques still represent by far the greatest proportion of diagnostic imaging examinations, and play an essential role in the growing number of advanced interventional procedures. This article describes some of the latest developments in X-ray imaging technology, using two products from the Philips range as examples: the Integris Allura cardiovascular system with 3D image reconstruction, and the BV Pulsera: a high-end, multi-functional mobile C-arm system with cardiac capabilities. (orig.)

  15. SMM x ray polychromator

    Science.gov (United States)

    Saba, J. L. R.

    1993-01-01

    The objective of the X-ray Polychromator (XRP) experiment was to study the physical properties of solar flare plasma and its relation to the parent active region to understand better the flare mechanism and related solar activity. Observations were made to determine the temperature, density, and dynamic structure of the pre-flare and flare plasma as a function of wavelength, space and time, the extent to which the flare plasma departs from thermal equilibrium, and the variation of this departure with time. The experiment also determines the temperature and density structure of active regions and flare-induced changes in the regions.

  16. The Evaluation study on diagnostic value of X-ray, CT, MRI on acromioclavicular joint dislocation%肩锁关节脱位的影像对比研究

    Institute of Scientific and Technical Information of China (English)

    包磊; 姚伟武; 辛鸿婕

    2011-01-01

    目的 探讨X线、CT及MR三种影像诊断技术对肩锁关节脱位的诊断价值.方法 回顾性分析35例经手术或关节镜证实的肩锁关节脱住患者的X线平片、CT和MRI材料,按照Rockwood分型标准进行分型,对照手术或关节镜结果,比较三种影像学方法诊断肩锁关节脱位的准确率、漏诊率和误诊率.结果 在本组35例肩锁关节脱位病例诊断中,X线平片诊断符合28例,占80.0%(28/35);漏诊3例,占8.6%(3/35);误诊4例,占11.4%(4/35).CT诊断符合30例,占85.7%(30/35);漏诊2例,占5.7%(2/35);误诊3例,占8.6%(3/35).MR诊断符合33例,占94.3%(33/35);漏诊1例,占2.85%(1/35);误诊1例,占2.85%(1/35).结论 MRI能够更为精确地显示肩锁关节脱位的韧带损伤情况,为临床正确分型及确定治疗方案提供了可靠依据.%Objective To evaluate the value of X-ray,CT and MR imaging in the diagnosis of acromioclavicular joint dislocation.Methods A retrospective study was performed to evaluate 35 acromioclavicular joint dislocations.Retrospective analysis of the X-ray,CT and MRI material of 35 cases which was confirmed by surgery or arthroscopic.According to Rockwood classification criteria, X-ray, CT and MRI were compared with surgery or arthroscopic result by the accuracy rate and missed diagnosis rate and misdiagnosis rate.Results X-ray diagnosis in 28 cases, accounting for 80.0% (28/35);missed in 3 cases,accounting for 8.6% (3/35);misdiagnosed in 4 cases, accounting for 11.4% (4/35).CT diagnosis in 30 cases, accounting for 85.7% (30/35);missed in 2 cases,accounting for 5.7% (2/35);misdiagnosed in 3 cases, accounting for 8.6% (3/35).MR diagnosis in 33 cases, accounting for 94.3% (33/35); missed in 1 case,accounting for 2.85% (1/35); misdiagnosed in 1 case, accounting for 2.85%(1/35).Conclusion MRI can help to detect the ligament injury of acromioclavicular joint dislocation and make accurate clinical classification in oder to determine the correct treatment

  17. HipMatch: an object-oriented cross-platform program for accurate determination of cup orientation using 2D-3D registration of single standard X-ray radiograph and a CT volume.

    Science.gov (United States)

    Zheng, Guoyan; Zhang, Xuan; Steppacher, Simon D; Murphy, Stephen B; Siebenrock, Klaus A; Tannast, Moritz

    2009-09-01

    The widely used procedure of evaluation of cup orientation following total hip arthroplasty using single standard anteroposterior (AP) radiograph is known inaccurate, largely due to the wide variability in individual pelvic orientation relative to X-ray plate. 2D-3D image registration methods have been introduced for an accurate determination of the post-operative cup alignment with respect to an anatomical reference extracted from the CT data. Although encouraging results have been reported, their extensive usage in clinical routine is still limited. This may be explained by their requirement of a CAD model of the prosthesis, which is often difficult to be organized from the manufacturer due to the proprietary issue, and by their requirement of either multiple radiographs or a radiograph-specific calibration, both of which are not available for most retrospective studies. To address these issues, we developed and validated an object-oriented cross-platform program called "HipMatch" where a hybrid 2D-3D registration scheme combining an iterative landmark-to-ray registration with a 2D-3D intensity-based registration was implemented to estimate a rigid transformation between a pre-operative CT volume and the post-operative X-ray radiograph for a precise estimation of cup alignment. No CAD model of the prosthesis is required. Quantitative and qualitative results evaluated on cadaveric and clinical datasets are given, which indicate the robustness and the accuracy of the program. HipMatch is written in object-oriented programming language C++ using cross-platform software Qt (TrollTech, Oslo, Norway), VTK, and Coin3D and is transportable to any platform.

  18. Accuracy and the influence of marrow fat on quantitative CT and dual-energy X-ray absorptiometry measurements of the femoral neck in vitro.

    Science.gov (United States)

    Kuiper, J W; van Kuijk, C; Grashuis, J L; Ederveen, A G; Schütte, H E

    1996-01-01

    Bone mineral measurements with quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA) were compared with chemical analysis (ChA) to determine (1) the accuracy and (2) the influence of bone marrow fat. Total bone mass of 19 human femoral necks in vitro was determined with QCT and DXA before and after defatting. ChA consisted of defatting and decalcification of the femoral neck samples for determination of bone mineral mass (BmM) and amount of fat. The mean BmM was 4.49 g. Mean fat percentage was 37.2% (23.3%-48.5%). QCT, DXA and ChA before and after defatting were all highly correlated (r > 0.96, p defatting the QCT values were on average 0.35 g less than BmM and the DXA values were on average 0.65 g less than BmM. After defatting, all bone mass values increased; QCT values were on average 0.30 g more than BmM and DXA values were 0.29 g less than BmM. It is concluded that bone mineral measurements of the femoral neck with QCT and DXA are highly correlated with the chemically determined bone mineral mass and that both techniques are influenced by the femoral fat content.

  19. Morphological quantification of hierarchical geomaterials by X-ray nano-CT bridges the gap from nano to micro length scales

    KAUST Repository

    Brisard, S.

    2012-01-30

    Morphological quantification of the complex structure of hierarchical geomaterials is of great relevance for Earth science and environmental engineering, among others. To date, methods that quantify the 3D morphology on length scales ranging from a few tens of nanometers to several hun-dred nanometers have had limited success. We demonstrate, for the first time, that it is possible to go beyond visualization and to extract quantitative morphological information from X-ray images in the aforementioned length scales. As examples, two different hierarchical geomaterials exhibiting complex porous structures ranging from nanometer to macroscopic scale are studied: a flocculated clay water suspension and two hydrated cement pastes. We show that from a single projection image it is possible to perform a direct computation of the ultra-small angle-scattering spectra. The predictions matched very well the experimental data obtained by the best ultra-small angle-scattering experimental setups as observed for the cement paste. In this context, we demonstrate that the structure of flocculated clay suspension exhibit two well-distinct regimes of aggregation, a dense mass fractal aggregation at short distance and a more open structure at large distance, which can be generated by a 3D reaction limited cluster-cluster aggregation process. For the first time, a high-resolution 3D image of fibrillar cement paste cluster was obtained from limited angle nanotomography.

  20. WE-FG-207A-05: Dedicated Breast CT as a Diagnostic Imaging Tool: Physics and Clinical Feasibility.

    Science.gov (United States)

    Karellas, A

    2016-06-01

    dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1-8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In

  1. WE-FG-207A-03: Low-Dose Cone-Beam Breast CT: Physics and Technology Development.

    Science.gov (United States)

    Boone, J

    2016-06-01

    dedicated breast CT. The development of large-area flat-panel detectors with field-of-view sufficient to image the entire breast in each projection enabled development of flat-panel cone-beam breast CT. More recently, the availability of complimentary metal-oxide semiconductor (CMOS) detectors with lower system noise and finer pixel pitch, combined with the development of x-ray tubes with focal spot dimensions similar to mammography systems, has shown improved spatial resolution and could improve visualization of microcalcifications. These technological developments promise clinical translation of low-dose cone-beam breast CT. Dedicated photon-counting breast CT (pcBCT) systems represent a novel detector design, which provide high spatial resolution (∼ 100µm) and low mean glandular dose (MGD). The CdTe-based direct conversion detector technology was previously evaluated and confirmed by simulations and basic experiments on laboratory setups [Kalender et al., Eur Radiol 22: 1-8, 2012]. Measurements of dose, technical image quality parameters, and surgical specimens on a pcBCT scanner have been completed. Comparative evaluation of surgical specimens showed that pcBCT outperformed mammography and digital breast tomosynthesis with respect to 3D spatial resolution, detectability of calcifications, and soft tissue delineation. Major barriers to widespread clinical use of BCT relate to radiation dose, imaging of microcalcifications, and adequate coverage of breast tissue near the chest wall. Adequate chest wall coverage is also technically challenging but recent progress in x-ray tube, detector and table design now enables full breast coverage in the majority of patients. At this time, BCT has been deemed to be suitable for diagnostic imaging but not yet for screening. The mean glandular dose (MGD) from BCT has been reported to be between 5.7 to 27.8 mGy, and this range is comparable to, and within the range of, the MGD of 2.6 to 31.6 mGy in diagnostic mammography. In

  2. 乳腺分叶状肿瘤的临床及X线钼靶表现分析%Phyllodes Tumor of the Breast X-ray Mammography and Clinical Performance Analysis

    Institute of Scientific and Technical Information of China (English)

    王建新

    2015-01-01

    目的:对乳腺分叶状肿瘤的临床及X线钼靶表现予以探讨。方法随机选取我院2013年1月~2013年12月间收治的乳腺分叶状肿瘤患者32例,对其临床资料及X线钼靶的影像资料予以回顾分析。结果本次研究中的所有患者都是因为无痛肿块就诊,并且大多数患者存在短期内的增大病史,对所有患者开展X线钼靶摄片检查。结论在为乳腺分叶状肿瘤患者开展实施诊断的过程中,仅仅依靠X线钼靶难以实施准确的诊断,还需要结合患者的临床表现开展诊断,大部分患者的肿块存在短期内增大现象,这可作为患者诊断的一个重要依据。%Objective Be explored phyllodes tumor of the breast X-ray mammography and clinical performance.MethodsRandomly selected in our hospital between January 2013 to December 2013 were treated breast phyllodes tumor patients 32 cases, clinical data and image data of X-ray mammography to be retrospectively.Results All patients in this study are as painless mass treatment, and most patients with a history of short-term increase, for all patients to carry out X-ray mammography examination. Conclusion In patients with lobular breast cancer diagnosis in their implementation process, relying solely on X-ray mammography is dififcult to implement an accurate diagnosis, but also requires a combination of clinical manifestations of conduct diagnosis, most patients in the short term to increase the presence of the mass phenomenon, which can be used as an important basis for patient diagnosis.

  3. Cholestrol granuloma of the breast incidentally detected on dynamic abdominal CT: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Sun Hye; Lee, Eun Hye; Hong, Hyun Sook; Kwak, Jeong Ja [Soonchunhyang University College of Medicine, Bucheon Hospital, Bucheon (Korea, Republic of)

    2016-01-15

    A breast cholesterol granuloma is an uncommon nodular breast lesion. We incidentally detected a persistently enhancing breast mass on the dynamic abdominal computed tomography (CT) of a 78-year-old woman. The mass decreased in diameter over 50 days following a core needle biopsy. This report is the first to describe the dynamic-enhanced CT features of a breast cholesterol granuloma.

  4. X线平片、CT及MRI在脊柱转移中诊断价值的比较%Diagnostic Values Comparison of X-ray,CT and MRI in Spinal Metastasis

    Institute of Scientific and Technical Information of China (English)

    傅顺斌; 李振武; 杨海丽; 杨涛; 姚永刚

    2014-01-01

    Objective To compare and analyze the diagnostic values of X-ray,XT and MRI in the spinal metastasis.Methods 30 cases of spinal metastasis patients were selected as the study objects,and al of these patients were given three examination approaches of X-ray,CT and MRI,then the examination results were compared.Results The study results showed that there were 171 times displaying a variety of metastatic spinal lesions with these three methods,in which 59 times of pathological changes were diagnosed with X-ray,accounting for 34.50%,and 9 cases were diagnosed as spinal metastasis,accounting for 30.0%;88 times of pathological changes were diagnosed with CT,accounting for 51.46%,and 16 cases were diagnosed as spinal metastasis,accounting for 53.33%;171 times of pathological changes were diagnosed with MRI, accounting for 100.0%,and 29 cases were diagnosed as spinal metastasis,accounting for 96.67%.There were significant dif erences among the pathological changes diagnostic times and spinal metastasis dianostic rate of these three methods ( <0.05).Conclusion X-ray, CT and MRI are important in the diagnosis of spinal metastasis, among which MRI has obvious and special advantages.%目的对比分析X线平片、CT及MRI在脊柱转移中的诊断价值。方法收集30例均接受X线平片、CT及MRI检查的脊柱转移瘤确诊患者,比较这3种检查手段对转移瘤的检出效果。结果三种检查方法显示脊柱转移的各种病变数目共171个。其中X线平片共检出59个病变,占总数的34.50%,诊断脊柱转移病例数9例,占总数的30.0%;CT共检出88个病变,占总数的51.46%,诊断脊柱转移病例数16例,占总数的53.33%;MRI共检出171个病变,占总数的100.0%,诊断脊柱转移病例数29例,占总数的96.67%。比较此3种方式对病变检出个数与脊柱转移瘤诊断率具有明显差异(P<0.05)。结论 X线平片、CT及MRI在脊柱转移中均具有重要的诊断价值,MRI在检出脊柱转

  5. Dedicated scanner for laboratory investigations on cone-beam CT/SPECT imaging of the breast

    Energy Technology Data Exchange (ETDEWEB)

    Mettivier, Giovanni, E-mail: mettivier@na.infn.i [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, I-80126 Napoli (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, I-80126 Napoli (Italy); Russo, Paolo, E-mail: russo@na.infn.i [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, I-80126 Napoli (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, I-80126 Napoli (Italy); Cesarelli, Mario; Ospizio, Roberto [Dipartimento di Ingegneria Biomedica, Elettronica e delle Telecomunicazioni, Universita di Napoli Federico II, I-80125 Napoli (Italy); Passeggio, Giuseppe; Roscilli, Lorenzo; Pontoriere, Giuseppe; Rocco, Raffaele [Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, I-80126 Napoli (Italy)

    2011-02-11

    We describe the design, realization and basic tests of a prototype Cone-Beam Breast Computed Tomography (CBBCT) scanner, combined with a SPECT head consisting of a compact pinhole gamma camera based on a photon counting CdTe hybrid pixel detector. The instrument features a 40 {mu}m focal spot X-ray tube, a 50 {mu}m pitch flat panel detector and a 1-mm-thick, 55 {mu}m pitch CdTe pixel detector. Preliminary imaging tests of the separate CT and gamma-ray units are presented showing a resolution in CT of 3.2 mm{sup -1} at a radial distance of 50 mm from the rotation axis and that the 5 and 8 mm hot masses ({sup 99m}Tc labeled with a 15:1 activity ratio with respect to the background) can be detected in planar gamma-ray imaging with a contrast-to-noise ratio of about 4.

  6. In situ visualization on cores with different boundary conditions through X-ray computed tomography scanner (CT-Scanner) during spontaneous imbibition

    Science.gov (United States)

    Kim, T.; Kovscek, A. R.

    2013-12-01

    Spontaneous imbibition (SI) is defined as displacement of non-wetting phase by wetting phase through the action of capillary forces in porous media. Spontaneous imbibition may occur as countercurrent or cocurrent multiphase flow. SI is an important test of rock wettability and is relevant to oil recovery from rocks of many different types of wettability. The rate of SI depends on permeability and water/oil relative permeability, medium shapes and boundary conditions, fluid viscosity, interfacial tension, and wettability, among other factors. This study investigates the effect of characteristic length (CL), boundary conditions (BC), and initial water saturation on the rate of spontaneous imbibition. We conduct countercurrent and cocurrent SI tests using cylindrical Berea sandstone (water-wet) and Indiana limestone (weakly wetting) through an X-ray computed tomography scanner and an imbibition cell with different boundary conditions and initial water saturations. Brine (1 wt% NaCl) is used as the wetting fluid. Also, decane (n-C10) and Blandol are used as non-wetting fluids, respectively to compare the effect of mobility ratio. The observed 2-D and 3-D saturation profile histories within each rock show clearly different imbibition patterns for each boundary condition. Also, low permeability limestones have more heterogeneous features than sandstones. The effect of characteristic length (CL) on the imbibition recovery curve was investigated using dimensionless time (tD). CL had an inverse effect on the rate of spontaneous imbibition within the same core samples. In addition, we used three different boundary conditions (BC) including (1) all faces open (AFO), (2) two ends open (TEO, i.e., inlet and outlet face), and (3) one end open (OEO, i.e., one face of the core) systems. BC experiments showed the effect of total open surface area for the oil production rate of spontaneous imbibition with different Swi. In addition, the generalized correlation (Aronofsy's equation

  7. SU-C-207-04: Reconstruction Artifact Reduction in X-Ray Cone Beam CT Using a Treatment Couch Model

    Energy Technology Data Exchange (ETDEWEB)

    Lasio, G; Hu, E; Zhou, J; Lee, M; Yi, B [University of Maryland School of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: to mitigate artifacts induced by the presence of the RT treatment couch in on-board CBCT and improve image quality Methods: a model of a Varian IGRT couch is constructed using a CBCT scan of the couch in air. The model is used to generate a set of forward projections (FP) of the treatment couch at specified gantry angles. The model couch forward projections are then used to process CBCT scan projections which contain the couch in addition to the scan object (Catphan phantom), in order to remove the attenuation component of the couch at any given gantry angle. Prior to pre-processing with the model FP, the Catphan projection data is normalized to an air scan with bowtie filter. The filtered Catphan projections are used to reconstruct the CBCT with an in-house FDK algorithm. The artifact reduction in the processed CBCT scan is assessed visually, and the image quality improvement is measured with the CNR over a few selected ROIs of the Catphan modules. Results: Sufficient match between the forward projected data and the x-ray projections is achieved to allow filtering in attenuation space. Visual improvement of the couch induced artifacts is achieved, with a moderate expense of CNR. Conclusion: Couch model-based correction of CBCT projection data has a potential for qualitative improvement of clinical CBCT scans, without requiring position specific correction data. The technique could be used to produce models of other artifact inducing devices, such as immobilization boards, and reduce their impact on patient CBCT images.

  8. Dual-time FDG-PET/CT in patients with potential breast cancer recurrence

    DEFF Research Database (Denmark)

    Baun, Christina; Falch Braas, Kirsten; Gerke, Oke;

    Dual-time FDG-PET/CT in patients with potential breast cancer recurrence: head-to-head comparison with CT and bonescintigraphy......Dual-time FDG-PET/CT in patients with potential breast cancer recurrence: head-to-head comparison with CT and bonescintigraphy...

  9. [Clinical applications of synchrotron radiation X-ray].

    Science.gov (United States)

    Uyama, C

    1994-09-01

    Synchrotron Radiation X-ray (SR X-ray) is an extremely strong X-ray source with a photon number more than 10(4) compared with that of the current X-ray tube. X-rays obtained by monochromatizing SR X-ray have been applied to new techniques for medical diagnosis. Several studies are now being conducted at the beam site for medical use at the Accumulation Ring of the High Energy Physics Research Institute, Tsukuba. Applications being studied include (1) energy subtraction coronary angiography. (2) microdetection of metas in samples excised from subjects. (3) monochromatic X-ray computed tomography and so on. Energy subtraction coronary angiography might have a safety advantage over the current selective coronary angiography. Microdetection of mandatory metals and poisonous heavy metals in in vivo samples contributes to the development of pathologic knowledge and clinical treatment of cancer and heavy metal toxications. Monochromatic X-ray CT is expected to detect diseases in the early stage due to increased accuracy in CT values.

  10. Synchrotron radiation X-ray microfluorescence techniques and biological applications

    Indian Academy of Sciences (India)

    R T Lopes; I Lima; G R Pereira; C A Perez

    2011-02-01

    Synchrotron X-ray imaging systems with fluorescence techniques was developed for biomedical researches in Brazilian Synchrotron Laboratory. An X-ray fluorescence microtomography system was implemented to analyse human prostate and breast samples and an X-ray microfluorescence system was implemented to study bone sites of human and animal samples with and without bone disorders.

  11. [PET/CT in breast cancer: an update].

    Science.gov (United States)

    Groheux, D; Moretti, J-L; Giacchetti, S; Hindié, E; Teyton, P; Cuvier, C; Bousquet, G; Misset, J-L; Boin, C; Espié, M

    2009-11-01

    The authors discuss the various roles of 18F-FDG PET/CT in the management of breast cancer. Roles of new tracers such as F-18 fluoro-L-thymidine (a marker of cell proliferation), 18-fluoro-17-B-estradiol (marker of estrogen receptor) and sodium fluoride (marker of bone matrix) are also mentioned. There is little justification for the use of FDG-PET/CT in patient with clinically T1 (occult distant metastases, notably, early osteomedullary infiltration. Thus, for these tumors, initial PET/CT can enable better intramodality treatment planning or a change in treatment. PET/CT as a whole-body examination is also very efficient in case of suspicion of recurrence. On the other hand, many studies show that this functional imaging could be used to assess early response to neoadjuvant chemotherapy or to chemotherapy of metastatic disease. 18FDG-PET/CT could thus become an unavoidable modality to answer various clinical situations.

  12. The color of X-rays Spectral X-ray computed tomography using energy sensitive pixel detectors

    CERN Document Server

    Schioppa, Enrico Junior

    Energy sensitive X-ray imaging detectors are produced by connecting a semiconductor sensor to a spectroscopic pixel readout chip. In this thesis, the applicability of such detectors to X-ray Computed Tomography (CT) is studied. A prototype Medipix based silicon detector is calibrated using X-ray fluorescence. The charge transport properties of the sensor are characterized using a high energy beam of charged particles at the Super Proton Synchrotron (SPS) at the European Center for Nuclear Research (CERN). Monochromatic X-rays at the European Synchrotron Radiation Facility (ESRF) are used to determined the energy response function. These data are used to implement a physics-based CT projection operator that accounts for the transmission of the source spectrum through the sample and detector effects. Based on this projection operator, an iterative spectral CT reconstruction algorithm is developed by extending an Ordered Subset Expectation Maximization (OSEM) method. Subsequently, a maximum likelihood based algo...

  13. Clinical Analysis of Color Doppler Ultrasound and X-ray Mammography in Screening Female Breast Cancer%彩超与X线钼靶筛查妇女乳腺癌临床分析

    Institute of Scientific and Technical Information of China (English)

    冯庆菁; 骆有寿; 徐惊; 黄晓芸; 朱超群; 周广慧

    2016-01-01

    Objective To discuss the effect of color Doppler ultrasound and x-ray mammography in screening female breast cancer. Methods 118 cases of patients with breast cancer diagnosed in our hospital from October 2012 to October 2015 were selected and screened and diagnosed with color Doppler ultrasound and X-ray mammography, and the diagnostic re-sults of them were compared. Results The coincident rate and detection rate of blood flow signal of color ultrasonic diagno-sis were obviously higher than those of x-ray mammography diagnosis, and the differences were obvious(P<0.05), the calci-fication detection rate of x-ray mammography was higher than that of the color Doppler ultrasound, and the difference was obvious(P<0.01), the coincident rate of pathological report and color ultrasonic diagnosis was 93.22%(110/118), the coinci-dent rate of X-ray mammography diagnosis was 79.66%(94/118), and the sensitivity, specificity, missed detection rate and misdiagnosis rate were respectively 93.55%, 97.70%, 6.45% and 2.30%. Conclusion Both color Doppler ultrasound and x-ray mammography in diagnosis of breast cancer are effective diagnostic methods, and each has its advantages and disadvan-tages, which can be selected according to the specific conditions of patients.%目的:探究彩超与X线钼靶对妇女乳腺癌的筛查效果。方法整群选择该院2012年10月—2015年10月确诊的118例乳腺癌患者,对其采用彩超和X线钼靶进行筛查诊断,对比两者诊断结果。结果彩超诊断符合率、血流信号检出率显著高于X线钼靶诊断,差异有统计学意义(P<0.05);X线钼靶的钙化检出率高于彩超,差异有统计学意义(P<0.01)。彩超诊断病理报告符合率为93.22%(110/118),X线钼靶诊断符合率为79.66%(94/118),彩超检查的灵敏度为93.55%,特异度为97.70%,漏检率为6.45%,误诊率为2.30%。结论彩超与X线钼靶诊断乳腺癌均为有效诊断方式,且各有利弊,可根据患者具体情况选择。

  14. Dedicated breast CT: Fibroglandular volume measurements in a diagnostic population

    Energy Technology Data Exchange (ETDEWEB)

    Vedantham, Srinivasan; Shi Linxi; Karellas, Andrew; O' Connell, Avice M. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Department of Imaging Sciences, University of Rochester Medical Center, Rochester, New York 14642 (United States)

    2012-12-15

    Purpose: To determine the mean and range of volumetric glandular fraction (VGF) of the breast in a diagnostic population using a high-resolution flat-panel cone-beam dedicated breast CT system. This information is important for Monte Carlo-based estimation of normalized glandular dose coefficients and for investigating the dependence of VGF on breast dimensions, race, and pathology. Methods: Image data from a clinical trial investigating the role of dedicated breast CT that enrolled 150 women were retrospectively analyzed to determine the VGF. The study was conducted in adherence to a protocol approved by the institutional human subjects review boards and written informed consent was obtained from all study participants. All participants in the study were assigned BI-RADS{sup Registered-Sign} 4 or 5 as per the American College of Radiology assessment categories after standard diagnostic work-up and underwent dedicated breast CT exam prior to biopsy. A Gaussian-kernel based fuzzy c-means algorithm was used to partition the breast CT images into adipose and fibroglandular tissue after segmenting the skin. Upon determination of the accuracy of the algorithm with a phantom, it was applied to 137 breast CT volumes from 136 women. VGF was determined for each breast and the mean and range were determined. Pathology results with classification as benign, malignant, and hyperplasia were available for 132 women, and were used to investigate if the distributions of VGF varied with pathology. Results: The algorithm was accurate to within {+-}1.9% in determining the volume of an irregular shaped phantom. The study mean ({+-} inter-breast SD) for the VGF was 0.172 {+-} 0.142 (range: 0.012-0.719). VGF was found to be negatively correlated with age, breast dimensions (chest-wall to nipple length, pectoralis to nipple length, and effective diameter at chest-wall), and total breast volume, and positively correlated with fibroglandular volume. Based on pathology, pairwise statistical

  15. Comparative Study on X-ray CT MRI of Sacroiliac Joint in Ankylosing Spondylitis%早期强直性脊柱炎骶髂关节病变的X线CT和MRI对比研究

    Institute of Scientific and Technical Information of China (English)

    马亚宁; 朱亚男; 李小民; 周和平; 王婷

    2013-01-01

    Objective: To study the imaging features of early ankylosing spondylitis( AS ). Method:59 cases of AS imaging data were analyzed and reviewed retrospectively. Result: Only 42 cases of the saemoiliae joints that suspicious singular were found in X-ray and 53 in CT and 59 MRI. It showed significant difference of diagnosis rats in the three method. The major expression of X-ray and CT were bone sclerosis parcel, cystic change of the articular subsurface bone structure, erosion and speculation. The major expression of MRI were bone marrow edema at the articular subsurface, articular-cartilage damage. In the enhanced sca-ning, the major Expression were bone marrow, synovial, articular-cartilage, the joint ligament showed different degrees of strengthening. Articular-cartilage( 8 cases ), the joint ligament( 5 cases )showed different degrees of strengthening. Conclusion: For the imaging diagnostic of early lesions in ankylosing spondylitis,CR exam-nination is the basic method that the value is very limited. CT ingrading lesions is more external, and can show the bone lesions more clearly. There is obvious advantage on MRI, by which AS can be early diagnosed with clinical.%目的:探讨强直性脊柱炎骶髂关节病变早期的影像学诊断价值.方法:收集经临床确诊的59例强直性脊柱炎早期病例,回顾分析其骶髂关节CR、CT及MRI表现.结果:X线发现42例骶髂关节可疑异常,CT发现53例表现异常,59例患者MRI表现均有异常,检出病例数对比差异显著(P﹤0.05).X线和CT的主要表现为:局部骨质硬化、侵蚀或囊性变、关节面欠光滑和毛刺感.MRI主要表现为骨髓水肿、关节软骨破坏,增强扫描可显示滑膜、关节软骨及关节韧带呈现不同程度强化.结论:强直性脊柱炎的早期影像学诊断,X线检查最为基本,但诊断意义有限;CT对分级较为客观,且能较好地显示骨质病变情况;MRI具有明显优势,结合临床,可做出早期诊断.

  16. 软骨母细胞瘤MRI及X线平片和CT的表现特征%The MRI features of chondroblastoma with correlation of X-ray and CT findings

    Institute of Scientific and Technical Information of China (English)

    上官景俊; 刘吉华; 韩娟娟; 邢成颜

    2008-01-01

    目的 研究软骨母细胞瘤的影像表现,探讨其MRI与X线平片、CT征象的对应关系.方法 分析16例经手术、病理证实的良性软骨母细胞瘤的影像资料,总结其MRI表现与X线平片、CT征象的对应关系.结果 16例软骨母细胞瘤均位于骨骺,大小为0.9 cm×0.8 cm×1.0 cm~4.8 cm×4.3 cm×5.1 cm,呈不同程度的分叶状.在T1WI上以等、低信号为主,T2WI上呈混杂信号,CT上为软组织密度,内见钙化和更低密度区.边缘呈长T1、短T2信号,在CT上表现为硬化边.MRI可见病灶周围有骨髓水肿,在X线和CT上表现为骨质硬化区.病灶邻近软组织肿胀.MRI显示骨膜异常9例,8例与病灶不相邻;X线和(或)CT显示骨膜新生骨6例.MRI显示关节积液12例,CT显示6例.MRI上病灶均呈不均匀强化,骨髓水肿、骨膜反应和软组织肿胀均见强化.软骨母细胞瘤在扩散加权成像(DWI)上呈等、高信号,在MR平扫中的等T1、等T2成分和长T1、长T2成分,以及骨髓水肿、骨膜反应和软组织肿胀在DWI上均呈高信号.结论 MRI和X线平片、CT从不同方面反映软骨母细胞瘤的病理改变,联合应用不同检查手段可更全面显示软骨母细胞瘤的特点.%Objective To investigate the MR imaging features of chondroblastoma,and to address the correlation with findings of X-ray radiography and CT.Methods The imaging findings including MRI,X-ray radiography and CT of 16 chondroblastomas proved by surgery and pathology were analyzed and correlated with each other. Results All sixteen chondroblastomas involved the epiphyses of long bones,with varying sizes from 0.8 cm to 5.1 cm and lobulation. They were iso- and hypo-intense on T1WI and had heterogeneous signals on T2WI.They were of soft tissue density on CT,and had areas of calcifications and low density.The rims were hypointense on both T1 WI and T2 WI and showed hyperdensity on CT. The lesions were surrounded by edema of bone marrow which was hypointense on T1 WI

  17. Topological X-Rays Revisited

    Science.gov (United States)

    Lynch, Mark

    2012-01-01

    We continue our study of topological X-rays begun in Lynch ["Topological X-rays and MRI's," iJMEST 33(3) (2002), pp. 389-392]. We modify our definition of a topological magnetic resonance imaging and give an affirmative answer to the question posed there: Can we identify a closed set in a box by defining X-rays to probe the interior and without…

  18. X-ray instrumentation for SR beamlines

    CERN Document Server

    Kovalchuk, M V; Zheludeva, S I; Aleshko-Ozhevsky, O P; Arutynyan, E H; Kheiker, D M; Kreines, A Y; Lider, V V; Pashaev, E M; Shilina, N Y; Shishkov, V A

    2000-01-01

    The main possibilities and parameters of experimental X-ray stations are presented: 'Protein crystallography', 'X-ray structure analysis', 'High-precision X-ray optics', 'X-ray crystallography and material science', 'X-ray topography', 'Photoelectron X-ray standing wave' that are being installed at Kurchatov SR source by A.V. Shubnikov Institute of Crystallography.

  19. REVIEW: X-ray computed tomography

    Science.gov (United States)

    Kalender, Willi A.

    2006-07-01

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention.

  20. 非骨化性纤维瘤的X线及CT诊断及鉴别诊断%Discussion on diagnosis and differential diagnosis of non ossifying fibroma using the X-ray and CT

    Institute of Scientific and Technical Information of China (English)

    苏宇

    2015-01-01

    Objective:To study on diagnosis and differential diagnosis of non ossifying fibroma using X-ray and CT,in order to provide a reliable basis for the X-ray and CT diagnostic value.Methods:36 patients with non ossifying fibroma were selected from March 2010 to September 2013.All of those patients were confirmed as non ossifying fibroma by pathology after operation.We analyzed the basic characteristics of non ossifying fibroma according with X-ray and CT findings before the operation.Results:Among those 36 patients with non ossifying fibroma,a total of 33 cases of non ossifying fibroma in long bones,in which 18 cases located in the metaphysis,10 cases located at the fixed end,5 cases located in the backbone of;2 cases in irregular bone sciatic,and 1 cases in irregular of vertebral body.The lesion diameter of those 36 cases averaged 0.7~8 cm.Patients with lesions mainly developed toward the long axis,and the most common shapes were round or oval.23 cases were found distinct lobulation in the lesion edge;34 cases were found sclerotic margins in the lesion edge.Among 36 patients with X-ray irradiation,there were 34 cases were found within the lesion separated,while there only 6 patients were found within the lesion separated when observed by CT;26 cases with bone shape enlargement,3 cases combined with pathological fracture.Conclusion:Non ossifying fibroma can find obvious features by X-ray and CT.Most of cases can be diagnosed before surgery.%目的:对非骨化性纤维瘤的X线平片、CT诊断以及鉴别诊断进行研究,为体现X线平片以及CT诊断的应用价值提供可靠依据。方法:2010年3月-2013年9月收治非骨化性纤维瘤患者36例。全体非骨化性纤维瘤患者后经手术病理均已获得证实,结合患者术前X线平片、CT结果,分析非骨化性纤维瘤的基本特征。结果:36例非骨化性纤维瘤患者的非骨化性纤维瘤所在部位以长骨最为多见,共计33例,其中位于干骺端18