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Sample records for conventional bone-subtraction ct

  1. Value of automatic bone subtraction in cranial CT angiography: comparison of bone-subtracted vs. standard CT angiography in 100 patients

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    Morhard, Dominik; Fink, Christian; Becker, Christoph; Reiser, Maximilian F.; Nikolaou, Konstantin [Ludwig-Maximilians-University of Munich, Institute of Clinical Radiology, Munich (Germany)

    2008-05-15

    Non-contrast-enhanced cranial computed tomography (NECT) and CT angiography (CTA) are the most frequently used modalities in the triage of patients with acute ischemic and hemorrhagic stroke. CTA bone removal can improve the delineation of vasculature closely adjacent to bony structures, which is sometimes limited in standard CTA. The aim of this study was the evaluation of the clinical benefit of bone subtraction (BS) regarding delineation of cerebral vasculature, reading time and depiction of vascular pathologies compared to standard CTA without BS. A total of 100 patients who underwent NECT and supraaortic CTA on a 64-slice CT system were retrospectively included in the study. Bone removal was performed by subtraction of the NECT data from the CTA data using a dedicated workstation. Standard and BS CTA of each patient was reviewed for delineation of cerebral vasculature (grading scale from 1 = 'excellent delineation' to 10 = 'hardly any delineation'), reading time and depiction of vascular pathologies (standardized catalog) by two blinded readers. For BS data sets, the quality of BS was rated by a combination of the criteria complete bone removal, depiction of vascular structures and sufficient quality for diagnostic evaluation. The use of BS significantly reduced reading time from 4.60 min to 3.49 min (p < 0.001). Performing BS, the quality of vascular delineation of the cerebral arteries, cerebral veins and cavernous segment of the ICA increased significantly as compared to standard CTA (1.70 vs. 2.70; 2.60 vs. 4.12; 2.35 vs. 4.40, all p < 0.001). Consensus reading showed 41 pathologies in 35 patients. Diagnosis was missed or wrong overall in 15 cases, with 3 missed aneurysms (CTA: 2 vs. BS: 1), 8 wrong stenotic findings (CTA: 3 vs. BS: 5) and 4 missed partial thromboses (CTA: 2 vs. BS: 2). Performing BS in supraaortic CTA for the evaluation of cerebral vasculature reduces reading time and improves delineation of vessels. Diagnostic

  2. Cerebral bone subtraction CT angiography using 80 kVp and sinogram-affirmed iterative reconstruction: contrast medium and radiation dose reduction with improvement of image quality

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    Nagayama, Yasunori [Kumamoto City Hospital, Department of Radiology, Kumamoto (Japan); Kumamoto University, Department of Diagnostic Radiology, Chuo-ku, Kumamoto (Japan); Nakaura, Takeshi; Oda, Seitaro; Kidoh, Masafumi; Utsunomiya, Daisuke; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Chuo-ku, Kumamoto (Japan); Tsuji, Akinori; Urata, Joji; Furusawa, Mitsuhiro; Yuki, Hideaki; Hirarta, Kenichiro [Kumamoto City Hospital, Department of Radiology, Kumamoto (Japan)

    2017-02-15

    The purpose of this study was to evaluate the feasibility of a contrast medium (CM), radiation dose reduction protocol for cerebral bone-subtraction CT angiography (BSCTA) using 80-kVp and sinogram-affirmed iterative reconstruction (SAFIRE). Seventy-five patients who had undergone BSCTA under the 120- (n = 37) or the 80-kVp protocol (n = 38) were included. CM was 370 mgI/kg for the 120-kVp and 296 mgI/kg for the 80-kVp protocol; the 120- and the 80-kVp images were reconstructed with filtered back-projection (FBP) and SAFIRE, respectively. We compared effective dose (ED), CT attenuation, image noise, and contrast-to-noise ratio (CNR) of two protocols. We also scored arterial contrast, sharpness, depiction of small arteries, visibility near skull base/clip, and overall image quality on a four-point scale. ED was 62% lower at 80- than 120-kVp (0.59 ± 0.06 vs 1.56 ± 0.13 mSv, p < 0.01). CT attenuation of the internal carotid artery (ICA) and middle cerebral artery (MCA) was significantly higher on 80- than 120-kVp (ICA: 557.4 ± 105.7 vs 370.0 ± 59.3 Hounsfield units (HU), p < 0.01; MCA: 551.9 ± 107.9 vs 364.6 ± 62.2 HU, p < 0.01). The CNR was also significantly higher on 80- than 120-kVp (ICA: 46.2 ± 10.2 vs 36.9 ± 7.6, p < 0.01; MCA: 45.7 ± 10.0 vs 35.7 ± 9.0, p < 0.01). Visibility near skull base and clip was not significantly different (p = 0.45). The other subjective scores were higher with the 80- than the 120-kVp protocol (p < 0.05). The 80-kVp acquisition with SAFIRE yields better image quality for BSCTA and substantial reduction in the radiation and CM dose compared to the 120-kVp with FBP protocol. (orig.)

  3. Subtraction CT angiography for evaluation of intracranial aneurysms: comparison with conventional CT angiography

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    Li, Qi; Li, Kewei; Xie, Peng [The First Affiliated Hospital, Chongqing Medical University, Department of Neurology, Chongqing (China); Lv, Fajin; Li, Yongmei; Luo, Tianyou [The First Affiliated Hospital, Chongqing Medical University, Department of Radiology, Chongqing (China)

    2009-09-15

    The purpose of our study was to compare the diagnostic performance of subtraction computed tomography angiography (CTA) with conventional nonsubtracted CTA and digital subtraction angiography (DSA) for the detection of intracranial aneurysms. A total of 76 patients underwent both subtraction CTA and conventional CTA for the detection and therapy planning of suspected intracranial aneurysms. Subtraction and conventional CTA images were independently assessed by two readers in a blinded manner. The possibility of endovascular treatment or surgical clipping was also assessed based on information provided by CT angiograms alone. In 64 patients, 75 aneurysms were present on DSA. On a per-aneurysm basis, the sensitivity of subtraction CTA was 98.6% for reader 1, and 100% for reader 2. However, sensitivity of conventional CTA was 94.6% for reader 1, and 93.3% for reader 2. Therapeutic decisions could be made regarding 63 patients based on information provided by subtraction CTA images. However, conventional CTA provided sufficient information to make this decision for 55 patients. Conventional CTA has limited sensitivity in detecting very small aneurysms as well as aneurysms adjacent to bone. Subtraction CTA performed on a 64-row multidetector CT is an accurate and promising diagnostic tool that seems to be equivalent to 2D DSA for the detection and pretreatment planning of intracranial aneurysms. (orig.)

  4. "Conventional" CT images from spectral measurements

    Science.gov (United States)

    Rajbhandary, Paurakh L.; Pelc, Norbert J.

    2016-03-01

    Spectral imaging systems need to be able to produce "conventional" images, and it's been shown that systems with energy discriminating detectors can achieve higher CNR than conventional systems by optimal weighting. Combining measured data in energy bins (EBs) and also combining basis material images have previously been proposed, but there are no studies systematically comparing the two methods. In this paper, we analytically evaluate the two methods for systems with ideal photon counting detectors using CNR and beam hardening (BH) artifact as metrics. For a 120-kVp polychromatic simulations of a water phantom with low contrast inserts, the difference of the optimal CNR between the two methods for the studied phantom is within 2%. For a polychromatic spectrum, beam-hardening artifacts are noticeable in EB weighted images (BH artifact of 3.8% for 8 EB and 6.9% for 2 EB), while weighted basis material images are free of such artifacts.

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

    Science.gov (United States)

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

    2017-05-11

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

  6. Internal noise in channelized Hotelling observer (CHO) study of detectability index-differential phase contrast CT vs. conventional CT

    Science.gov (United States)

    Tang, Xiangyang; Yang, Yi

    2014-03-01

    The channelized Hotelling observer (CHO) model, wherein internal noise plays an important role to account for the psychophysiological uncertainty in human's visual perception, has found extensive applications in the assessment of image quality in nuclear medicine, mammography and conventional CT. Recently, we extended its application to investigating the detectability index of differential phase contrast (DPC) CT-an emerging CT technology with the potential of increasing the capability in soft tissue differentiation. We found that the quantitative determination of internal noise in the CHO study of DPC-CT's detectability index should differ from that in the conventional CT. It is believed that the root cause of such a difference lies in the distinct noise spectra between the DPC-CT and conventional CT. In this paper, we present the preliminary results and investigate the adequate strategies to quantitatively determine the internal noise of CHO model for its application in the assessment of image quality in DPC-CT and its comparison with that of the conventional CT.

  7. Cerebral artery evaluation of dual energy CT angiography with dual source CT

    Institute of Scientific and Technical Information of China (English)

    MA Rui; LIU Cheng; DENG Kai; SONG Shao-juan; WANG Dao-ping; HUANG Ling

    2010-01-01

    Background Conventional computed tomography angiography (CTA) is time consuming, user-dependent and has poor image quality in skull base region. This study assessed the feasibility of a new method, dual energy CTA for depicting the cerebral artery.Methods Phantom scan was done with head CTA sequences on dual source CT and 64 spiral CT for radiation dose calculation. Dual energy CTA was done with dual source CT on 36 patients who were suspected of having cerebral vascular disease. Three series axial images in 0.75 mm thick, 0.4 mm increment were acquired, which were named with 80 kV, 140 kV and merged images; 80 kV and 140 kV images were transferred into dual energy software, and maximum intensity projection (MIP) image was generated quickly by dual energy bone remove (DEBR group); merged images were transferred into In Space software to acquire MIP image through manual conventional bone remove (CoBR group). Post processing time and reading time were compared. Image qualities of the two groups were compared, mainly focusing on skull base segments of internal carotid artery and bone subtraction. ANOVA and SNK tests were applied for radiation dose comparison. Student's t test and Wilcoxon rank sum test were applied for assessing differences between data for significance. Cohen's kappa was used for interobserver agreement. Results Radiation dose of phantom scan showed dual energy CTA was between digital bone subtraction and conventional CTA. The post processing time and reading time were much shorter in DEBR than CoBR, and image quality in skull base was much higher in DEBR than CoBR (P0.5). Interobserver agreement for all vessel segments was excellent (kappa=0.97). Conclusions Dual energy CTA is a reliable, new modality for depicting cerebral artery, overcoming the limitation of conventional CTA in the skull base region. It can save much time in post processing and reading than conventional CTA.

  8. Imaging performance in differential phase contrast CT compared with the conventional CT-noise equivalent quanta NEQ(k)

    Science.gov (United States)

    Tang, Xiangyang; Yang, Yi; Tang, Shaojie

    2012-03-01

    The grating-based x-ray differential phase contrast (DPC) CT is emerging as a new technology with the potential for extensive preclinical and clinical applications. In general, the performance of an imaging system is jointly determined by its signal property (modulation transfer function-MTF(k)) and noise property (noise power spectrum-NPS(k)), which is characterized by its spectrum of noise equivalent quanta. As reported by us previously, owing to an adoption of the Hilbert filtering for image reconstruction in the fashion of filtered backprojection (FBP), the noise property of DPC-CT characterized by its NPS(k) differs drastically from that of the conventional attenuation-based CT (1/|k| trait vs. |k| trait). In this work, via system analysis, modeling and simulated phantom study, we initially investigate the signal property of DPC-CT characterized by its MTF(k) and compare it with that of the conventional CT. In addition, we investigate the DPC-CT's spectrum of noise equivalent quanta NEQ(k) - the most important figure of merit (FOM) in the assessment of an imaging system's performance - by taking the MTF(k) and NPS(k) jointly into account. Through such a thorough investigation into both the signal and noise properties, the imaging performance of DPC-CT and its potential over the conventional attenuation-based CT can be fully understood and appreciated.

  9. Detectability index of differential phase contrast CT compared with conventional CT: a preliminary channelized Hotelling observer study

    Science.gov (United States)

    Tang, Xiangyang; Yang, Yi; Tang, Shaojie

    2013-03-01

    Under the framework of model observer with signal and background exactly known (SKE/BKE), we investigate the detectability of differential phase contrast CT compared with that of the conventional attenuation-based CT. Using the channelized Hotelling observer and the radially symmetric difference-of-Gaussians channel template , we investigate the detectability index and its variation over the dimension of object and detector cells. The preliminary data show that the differential phase contrast CT outperforms the conventional attenuation-based CT significantly in the detectability index while both the object to be detected and the cell of detector used for data acquisition are relatively small. However, the differential phase contrast CT's dominance in the detectability index diminishes with increasing dimension of either object or detector cell, and virtually disappears while the dimension of object or detector cell approaches a threshold, respectively. It is hoped that the preliminary data reported in this paper may provide insightful understanding of the differential phase contrast CT's characteristic in the detectability index and its comparison with that of the conventional attenuation-based CT.

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

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    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.

  11. Conventional CT for the prediction of an involved circumferential resection margin in primary rectal cancer

    NARCIS (Netherlands)

    Wolberink, Steven V. R. C.; Beets-Tan, Regina G. H.; de Haas-Kock, Danielle F. M.; Span, Mark M.; van de Jagt, Eric J.; van de Velde, Cornelis J. H.; Wiggers, Theo

    2007-01-01

    Purpose: To determine the accuracy of conventional computed tomography (CT) scan in the preoperative prediction of an involved circumferential resection margin (CRM) in primary rectal cancer. Methods: 125 patients with biopsy-proven adenocarcinoma of the rectum underwent CT of the abdomen before und

  12. Artifacts in conventional computed tomography (CT) and free breathing four-dimensional CT induce uncertainty in gross tumor volume determination

    DEFF Research Database (Denmark)

    Persson, Gitte Fredberg; Nygaard, Ditte Eklund; Af Rosenschöld, Per Munck;

    2011-01-01

    PURPOSE: Artifacts impacting the imaged tumor volume can be seen in conventional three-dimensional CT (3DCT) scans for planning of lung cancer radiotherapy but can be reduced with the use of respiration-correlated imaging, i.e., 4DCT or breathhold CT (BHCT) scans. The aim of this study...... was to compare delineated gross tumor volume (GTV) sizes in 3DCT, 4DCT, and BHCT scans of patients with lung tumors. METHODS AND MATERIALS: A total of 36 patients with 46 tumors referred for stereotactic radiotherapy of lung tumors were included. All patients underwent positron emission tomography (PET)/CT, 4DCT......, and BHCT scans. GTVs in all CT scans of individual patients were delineated during one session by a single physician to minimize systematic delineation uncertainty. The GTV size from the BHCT was considered the closest to true tumor volume and was chosen as the reference. The reference GTV size...

  13. Attenuation correction in cardiac PET/CT with three different CT protocols: a comparison with conventional PET

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    Souvatzoglou, Michael [Nuklearmedizinische Klinik und Poliklinik der Technischen Universitaet Muenchen, Munich (Germany); Nuklearmedizinische Klinik der Technischen Universitaet Muenchen, Munich (Germany); Bengel, Frank; Kruschke, Coletta; Fernolendt, Helga; Lee, Denise; Schwaiger, Markus; Nekolla, Stephan G. [Nuklearmedizinische Klinik und Poliklinik der Technischen Universitaet Muenchen, Munich (Germany); Busch, Raymonde [Institut fuer Statistik und Epidemiologie der Technischen Universitaet Muenchen, Munich (Germany)

    2007-12-15

    CT-based attenuation correction may influence cardiac PET owing to its higher susceptibility to misalignment compared with conventional {sup 68}Ge transmission scans. The aims of this study were to evaluate whether CT attenuation correction leads to changes in tracer distribution compared with conventional cardiac PET and to determine a suitable CT protocol. A total of 27 patients underwent PET/CT and subsequently a PET scan. Twenty patients received a low-dose CT (LDCT group; 120 kV, 26 mA, 8-s scan time), seven patients a slow CT (SCT group; 120 kV, 99 mA, 46-s scan time) and ten patients an ultra-low-dose CT (ULDCT group; 80 kV, 13 mA, 5-s scan time) as the transmission scan in PET/CT. Polar maps were divided into 17 segments and regression analysis was computed in every scan pair (CT attenuation corrected-{sup 68}Ge attenuation corrected). Correlation coefficient (r), the slope (s) and the offset (os) of the regression line were determined. Visual assessment of misalignment between the transmission and emission data was performed. The effective dose of the different transmission scans was calculated. Overall, there was a moderate correlation between the mean values measured in all segments on PET/CT and on PET when using LDCT (r=0.78, p<0.0001), SCT (r=0.79, p<0.0001) and ULDCT (r=0.82, p<0.0001). No differences were observed when comparing the scores assigned in the visual misalignment assessment in the three groups (p=0.12). The differences between the results from the regression analysis observed in the respective groups were not statistically significant (Kruskal-Wallis p=0.11 for r, p=0.67 for s and p=0.27 for os). The effective dose was lowest for the ULDCT. Our study shows that CT-based attenuation correction is feasible for cardiac PET imaging. The results indicate that ultra-low-dose CT is the preferable choice for transmission scanning. (orig.)

  14. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

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    Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

    2015-07-15

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  15. Dual energy CT of peripheral arteries: Effect of automatic bone and plaque removal on image quality and grading of stenoses

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    Meyer, B.C. [Charite - University Hospital, Campus Benjamin Franklin, Department of Radiology and Nuclear Medicine, Hindenburgdamm 30, 12200 Berlin (Germany)], E-mail: Bernhard.Meyer@charite.de; Werncke, T. [Charite - University Hospital, Campus Benjamin Franklin, Department of Radiology and Nuclear Medicine, Hindenburgdamm 30, 12200 Berlin (Germany); Hopfenmueller, W. [Charite - University Hospital, Campus Benjamin Franklin, Department of Biometry and Clinical Epidemiology, Hindenburgdamm 30, 12200 Berlin (Germany); Raatschen, H.J.; Wolf, K.-J.; Albrecht, T. [Charite - University Hospital, Campus Benjamin Franklin, Department of Radiology and Nuclear Medicine, Hindenburgdamm 30, 12200 Berlin (Germany)

    2008-12-15

    Purpose: To evaluate the effect of automatic bone and plaque removal on image quality and grading of steno-occlusive lesions in patients undergoing dual energy CT angiography (CTA) of lower extremity. Materials and methods: Dual energy (DE) runoff CTA was performed in 50 patients using the following parameters: collimation 2 x 32 x 0.6; tube potentials, 80 kV and 140 kV; reconstructed slice thickness 1 mm. 100 mL iomeprol 400 and 50 mL saline were injected at 4 mL/s. Separate datasets were calculated for each of the two tubes and used to generate automatically bone-subtracted images (ABS) as well as bone and plaque subtracted images (ABPS). Residual bone in the ABS dataset was removed manually (=ABS-B dataset). In addition, a weighted average dataset from both dual energy acquisitions resembling a routine 120 kV CT acquisition was used for standard manual bone subtraction (MBS). Operator time for bone removal was measured. Effectiveness of bone subtraction and presence of vessel erosions was assessed by two readers in consensus. Stenosis grading in plaque subtracted and unsubtracted images was assessed and correlated. Results: Residual bone fragments (ribs: 46%, patella: 25%, spine: 4%, pelvis: 2%, tibia 2% of patients) were only observed with ABS. The time needed to manually remove these residual bones was 2.1 {+-} 1.1 min and was significantly lower than the duration of manual bone removal (6.8 {+-} 2.0 min, p < 0.0001, paired t-test). A total of 1159 arteries were analyzed. Compromising vessel erosions were observed less frequently in the ABS-B dataset (10.6%) than in the MBS dataset (15.2%, p < 0.001, wilcoxon's signed rank test). A total of 817 steno-occlusive lesions were assessed. While the agreement of grading of steno-occlusive lesions was good at the levels of the aorta and the pelvic arteries ({kappa} = 0.70 in both, Cohen's kappa statistics), it was moderate at the level of the thigh arteries ({kappa} = 0.57) and poor at the level of the calf

  16. Feasibility of Nanoparticle-Guided Radiation Therapy (NGRT) Using a Conventional CT Scanner

    Science.gov (United States)

    2010-10-01

    created and used as the input geometry for dose calculations within the Monte Carlo N-Particle eXtended ( MCNPX ) program. MCNPX is a generalized...conventional CT scanners (SOW 1b).11,12 The energy spectra were input into MCNPX for radiation energy deposition calculations (SOW 1c-d). An example of...the program developed to perform the dose calculations is shown within the appendix. Because the programming language used within MCNPX is Fortran

  17. Diagnosis of Peripheral Lung Lesions via Conventional Flexible Bronchoscopy with Multiplanar CT Planning

    Directory of Open Access Journals (Sweden)

    Marianne Anastasia De Roza

    2016-01-01

    Full Text Available Background. Conventional flexible bronchoscopy has limited sensitivity in the diagnosis of peripheral lung lesions and is dependent on lesion size. However, advancement of CT imaging offers multiplanar reconstruction facilitating enhanced preprocedure planning. This study aims to report efficacy and safety while considering the impact of patient selection and multiplanar CT planning. Method. Prospective case series of patients with peripheral lung lesions suspected of having lung cancer who underwent flexible bronchoscopy (forceps biopsy and lavage. Endobronchial lesions were excluded. Patients with negative results underwent CT-guided transthoracic needle aspiration, surgical biopsy, or clinical-radiological surveillance to establish the final diagnosis. Results. 226 patients were analysed. The diagnostic yield of bronchoscopy was 80.1% (181/226 with a sensitivity of 84.2% and specificity of 100%. In patients with a positive CT-Bronchus sign, the diagnostic yield was 82.4% compared to 72.8% with negative CT-Bronchus sign (p=0.116. Diagnostic yield was 84.9% in lesions > 20 mm and 63.0% in lesions ≤ 20 mm (p=0.001. Six (2.7% patients had transient hypoxia and 2 (0.9% had pneumothorax. There were no serious adverse events. Conclusion. Flexible bronchoscopy with appropriate patient selection and preprocedure planning is more efficacious in obtaining a diagnosis in peripheral lung lesions compared to historical data. This trial is registered with ClinicalTrials.gov Identifier: NCT01374542.

  18. Comparison of 64-Detector CT Colonography and Conventional Colonoscopy in the Detection of Colorectal Lesions

    Directory of Open Access Journals (Sweden)

    Devir

    2016-01-01

    Full Text Available Background Colon cancer is a leading cause of morbidity and mortality in developed countries. The early detection of colorectal cancer using screening programs is important for managing early-stage colorectal cancers and polyps. Modalities that allow examination of the entire colon are conventional colonoscopy, double contrast barium enema examination and multi-detector computed tomography (MDCT colonography. Objectives To compare CT colonography and conventional colonoscopy results and to evaluate the accuracy of CT colonography for detecting colorectal lesions. Patients and Methods In a prospective study performed at Gastroenterology and Radiology Departments of Medical Faculty of Eskisehir Osmangazi University, CT colonography and colonoscopy results of 31 patients with family history of colorectal carcinoma, personal or family history of colorectal polyps, lower gastrointestinal tract bleeding, change in bowel habits, iron deficiency anemia and abdominal pain were compared. Regardless of the size, CT colonography and conventional colonoscopy findings for all the lesions were cross - tabulated and the sensitivity, specificity, and positive and negative predictive values were calculated. To assess the agreement between CT colonography and conventional colonoscopy examinations, the Kappa coefficient of agreementt was used. Statistical analysis was performed by SPSS ver 15.0. Results Regardless of the size, MDCT colonography showed 83% sensitivity and 95% specificity, with a positive predictive value of 95% and a negative predictive value of 83% for the detection of colorectal polyps and masses. MDCT colonography displayed 92% sensitivity and 95% specificity, with a positive predictive value of 92% and a negative predictive value of 95% for polyps ≥ 10 mm. For polyps between 6mm and 9 mm, MDCT colonography displayed 75% sensitivity and 100% specificity, with a positive predictive value of 100% and a negative predictive value of 90%. For polyps

  19. Imaging of cochlear implant electrode array with flat-detector CT and conventional multislice CT: comparison of image quality and radiation dose.

    Science.gov (United States)

    Struffert, Tobias; Hertel, Victoria; Kyriakou, Yannis; Krause, Jens; Engelhorn, Tobias; Schick, Bernhard; Iro, Heinrich; Hornung, Joachim; Doerfler, Arnd

    2010-04-01

    Cochlear implantation assessment is possible using commercially available standard flat-detector computed tomography (FD-CT) protocols. Image quality is superior to multislice CT (MSCT). The radiation dose of FD-CT is lower in comparison with MSCT standard protocols and may therefore overcome the limitations of MSCT in the evaluation of cochlear implants. FD-CT offers higher spatial resolution than MSCT. Our objective was to compare the image quality of FD-CT to conventional MSCT in the visualization of a cochlear implant electrode array with respect to radiation exposure. An isolated temporal bone specimen was scanned using a commercially available FD-CT system and a 4 and 64 row MSCT scanner. Different scanning protocols were used. Image quality was assessed by four independent readers using a scoring system with different criteria describing delineation of the cochlea and the electrode array, image noise and spatial resolution. Radiation dose was measured using the CT dose index (CTDI) and a 16 cm acrylic phantom. Image quality was rated superior for FD-CT for all criteria by all readers. Single electrode contacts were only visible in FD-CT and assessment of implant position was improved by FD-CT. The radiation dose of FD-CT was half that of MSCT standard protocols.

  20. Characterization of imaging performance in differential phase contrast CT compared with the conventional CT: Spectrum of noise equivalent quanta NEQ(k)

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    Tang Xiangyang; Yang Yi; Tang Shaojie [Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Drive, C-5018, Atlanta, Georgia 30322 (United States)

    2012-07-15

    Purpose: Differential phase contrast CT (DPC-CT) is emerging as a new technology to improve the contrast sensitivity of conventional attenuation-based CT. The noise equivalent quanta as a function over spatial frequency, i.e., the spectrum of noise equivalent quanta NEQ(k), is a decisive indicator of the signal and noise transfer properties of an imaging system. In this work, we derive the functional form of NEQ(k) in DPC-CT. Via system modeling, analysis, and computer simulation, we evaluate and verify the derived NEQ(k) and compare it with that of the conventional attenuation-based CT. Methods: The DPC-CT is implemented with x-ray tube and gratings. The x-ray propagation and data acquisition are modeled and simulated through Fresnel and Fourier analysis. A monochromatic x-ray source (30 keV) is assumed to exclude any system imperfection and interference caused by scatter and beam hardening, while a 360 Degree-Sign full scan is carried out in data acquisition to avoid any weighting scheme that may disrupt noise randomness. Adequate upsampling is implemented to simulate the x-ray beam's propagation through the gratings G{sub 1} and G{sub 2} with periods 8 and 4 {mu}m, respectively, while the intergrating distance is 193.6 mm (1/16 of the Talbot distance). The dimensions of the detector cell for data acquisition are 32 Multiplication-Sign 32, 64 Multiplication-Sign 64, 96 Multiplication-Sign 96, and 128 Multiplication-Sign 128 {mu}m{sup 2}, respectively, corresponding to a 40.96 Multiplication-Sign 40.96 mm{sup 2} field of view in data acquisition. An air phantom is employed to obtain the noise power spectrum NPS(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 refraction coefficient n= 1 -{delta}+i{beta}= 1 -2.5604 Multiplication-Sign 10{sup -7}+i1.2353 Multiplication-Sign 10{sup -10} is placed in air to measure the edge transfer function, line spread function

  1. Characterization of imaging performance in differential phase contrast CT compared with the conventional CT: Spectrum of noise equivalent quanta NEQ(k)

    Science.gov (United States)

    Tang, Xiangyang; Yang, Yi; Tang, Shaojie

    2012-01-01

    Purpose: Differential phase contrast CT (DPC-CT) is emerging as a new technology to improve the contrast sensitivity of conventional attenuation-based CT. The noise equivalent quanta as a function over spatial frequency, i.e., the spectrum of noise equivalent quanta NEQ(k), is a decisive indicator of the signal and noise transfer properties of an imaging system. In this work, we derive the functional form of NEQ(k) in DPC-CT. Via system modeling, analysis, and computer simulation, we evaluate and verify the derived NEQ(k) and compare it with that of the conventional attenuation-based CT. Methods: The DPC-CT is implemented with x-ray tube and gratings. The x-ray propagation and data acquisition are modeled and simulated through Fresnel and Fourier analysis. A monochromatic x-ray source (30 keV) is assumed to exclude any system imperfection and interference caused by scatter and beam hardening, while a 360° full scan is carried out in data acquisition to avoid any weighting scheme that may disrupt noise randomness. Adequate upsampling is implemented to simulate the x-ray beam's propagation through the gratings G1 and G2 with periods 8 and 4 μm, respectively, while the intergrating distance is 193.6 mm (1/16 of the Talbot distance). The dimensions of the detector cell for data acquisition are 32 × 32, 64 × 64, 96 × 96, and 128 × 128 μm2, respectively, corresponding to a 40.96 × 40.96 mm2 field of view in data acquisition. An air phantom is employed to obtain the noise power spectrum NPS(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 refraction coefficient n = 1 − δ + iβ = 1 −2.5604 × 10−7 + i1.2353 × 10−10 is placed in air to measure the edge transfer function, line spread function and then modulation transfer function MTF(k), of both DPC-CT and the conventional attenuation-based CT. The x-ray flux is set at 5 × 106 photon/cm2 per projection and

  2. Conventional radiographie diagnosis and CT of the temporomandibular joint in myoarthropathy

    Energy Technology Data Exchange (ETDEWEB)

    Huels, A.; Schulte, W.; Walter, E.

    1984-08-01

    Conventional radiogrpahie Diagnosis and CT of the Temporomandibular Joint in Myoarthropathy. - Clinical utilization of the high resolution, thin-slice CT (slice thickness: 1 mm) makes it possible to systemize the bony structure changes of the joint correlated with dysfunctions. Using this technique total evaluations of this complex can be made. - In patients suffering from myoarthropathy, the partially typical changes in both the functional anatomy, as well as in form, structure and topography of specific regions of the joint can be viewed objectively. - The alteration process of the temporomandibular joint is considered causal in connection with muscular disfunctions, which often lay the foundation for chronic pain conditions, in the regions of the face and head. - The broad spectrum of conventional radiogrpahic techniques documents, on one hand, the extremely unfavorable anatomy of the temporomandibular joint with regard to radiography. On the other hand, it also implies a certain amount of diagnostic uncertainty in this region. - Comment is made concerning the informational value as well as the limits of the most important radiologic techniques. It is of utmost importance to evaluate the radiographic findings of the temporomandibular joint in myoarthropathies with a clinical functional analysis, which is easy to carry out.

  3. Evaluation of bone substitute materials: comparison of flat-panel based volume CT to conventional multidetector CT.

    Science.gov (United States)

    Sauerbier, Sebastian; Duttenhoefer, Fabian; Sachlos, Elefterios; Haberstroh, Jörg; Scheifele, Christian; Wrbas, Karl-Thomas; Voss, Pit Jacob; Veigel, Egle; Smedek, Jörg; Ganter, Philip; Tuna, Taskin; Gutwald, Ralf; Palmowski, Moritz

    2013-10-01

    Over the last decade tissue engineering has emerged as a key factor in bone regeneration within the field of cranio-maxillofacial surgery. Despite this in vivo analysis of tissue-engineered-constructs to monitor bone rehabilitation are difficult to conduct. Novel high-resolving flat-panel based volume CTs (fp-VCT) are increasingly used for imaging bone structures. This study compares the potential value of novel fp-VCT with conventional multidetector CT (MDCT) based on a sheep sinus floor elevation model. Calcium-hydroxyapatite reinforced collagen scaffolds were populated with autologous osteoblasts and implanted into sheep maxillary sinus. After 8, 16 and 24 weeks MDCT and fp-VCT scans were performed to investigate the volume of the augmented area; densities of cancellous and compact bone were assessed as comparative values. fp-VCT imaging resulted in higher spatial resolution, which was advantageous when separating closely related anatomical structures (i.e. trabecular and compact bone, biomaterials). Fp-VCT facilitated imaging of alterations occurring in test specimens over time. fp-VCTs therefore displayed high volume coverage, dynamic imaging potential and superior performance when investigating superfine bone structures and bone remodelling of biomaterials. Thus, fp-VCTs may be a suitable instrument for intraoperative imaging and future in vivo tissue-engineering studies.

  4. 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

  5. Detection of flat colorectal polyps at screening CT colonography in comparison with conventional polypoid lesions

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Takashi; Urata, Joji [Diagnostic Imaging Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Mitsuzaki, Katsuhiko; Matsuda, Katsuhiko; Kawakami, Megumi [Medical Examination Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Utsunomiya, Daisuke; Yamamura, Sadahiro; Yamashita, Yasuyuki [Diagnostic Radiology, Faculty of Life Sciences, Kumamoto Univ., Kumamoto (Japan)], e-mail: utsunomi@kumamoto-u.ac.jp

    2012-09-15

    Background: Although the screening of small, flat polyps is clinically important, the role of CT colonography (CTC) screening in their detection has not been thoroughly investigated. Purpose: To evaluate the detection capability and usefulness of CTC in the screening of flat and polypoid lesions by comparing CTC with optic colonoscopy findings as the gold standard. Material and Methods: We evaluated the CTC detection capability for flat colorectal polyps with a flat surface and a height not exceeding 3 mm (n = 42) by comparing to conventional polypoid lesions (n = 418) according to the polyp diameter. Four types of reconstruction images including multiplanar reconstruction, volume rendering, virtual gross pathology, and virtual endoscopic images were used for visual analysis. We compared the abilities of the four reconstructions for polyp visualization. Results: Detection sensitivity for flat polyps was 31.3 %, 44.4 %, and 87.5 % for lesions measuring 2-3 mm, 4-5 mm, and {>=}6 mm, respectively; the corresponding sensitivity for polypoid lesions was 47.6 %, 79.0 %, and 91.7 %. The overall sensitivity for flat lesions (47.6%) was significantly lower than polypoid lesions (64.1%). Virtual endoscopic imaging showed best visualization among the four reconstructions. Colon cancers were detected in eight patients by optic colonoscopy, and CTC detected colon cancers in all eight patients. Conclusion: CTC using 64-row multidetector CT is useful for colon cancer screening to detect colorectal polyps while the detection of small, flat lesions is still challenging.

  6. Gastro-duodenal perforations: conventional plain film, US and CT findings in 166 consecutive patients

    Energy Technology Data Exchange (ETDEWEB)

    Grassi, Roberto; Romano, Stefania E-mail: stefromano@libero.it; Pinto, Antonio; Romano, Luigia

    2004-04-01

    Introduction: Gastro-duodenal perforations may be suspected in patients with history of ulceration, who present with acute pain and abdominal wall rigidity, but radiological findings in these cases may be unable to confirm a clinical diagnosis. The aim of our study was to report our experience in the diagnosis of gastro-duodenal perforation by conventional radiography, US and CT examinations. Material and methods: We retrospectively reviewed medical records of 166 consecutive patients who presented in the last 2 years to our institutions with symptoms of acute abdomen and submitted to surgery at the Emergency Unit of the ''A.Cardarelli'' Hospital of Naples with a surgical finding of perforated gastro-duodenal ulcer. The evidence of free intraperitoneal air on abdominal plain film was considered as a direct or suggestive finding of perforation. Evidence of intraperitoneal free fluid and/or reduced intestinal peristalsis at sonographic examination were considered indirect signs of gastro-duodenal perforation. Evidence of free peritoneal gas at CT was considered as a direct evidence of gastro-duodenal perforation. Results: Twenty patients underwent immediate surgery with no preoperative imaging evaluation, in 10 of them the site of perforation was found in a juxta-pyloric region and in the others at level of duodenum. In 146 patients submitted to serial radiological investigations before surgery, the site of perforation was in 56 (38.3%) duodenal, in 52 (35.6%) juxta-pyloric, in 28 (19.1%) gastric and in 10 (6.8%) pyloric. The cause of perforation was in all cases gastric or duodenal ulceration, in seven cases involving pancreatic parenchyma. In 110 (75.4%) patients with direct findings of perforation, in 94 cases (85.5%) the correct diagnosis was established on abdominal plain film, in two (1.8%) with radiographic and sonographic examinations and in 14 (12.7%) on CT findings. In 36 (24,6%) patients with no direct findings of perforation, only 24

  7. Value of surveillance {sup 18}F FDG PET/CT in colorectal cancer:comparison with conventional imaging studies

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun Kyoung; Yoo, Ie Ryung; Park, Hye Lim; Choi, Hyun Su; Han, Eun Ji; Kim, Sung Hoon; Chung, Soo Kyo; O, Joo Hyun [The Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2012-09-15

    To assess the value of PET/CT for detecting local or distant recurrence in patients who undergo surgery for colorectal cancer (CRC)and to compare the accuracy of PET/CT to that of conventional imaging studies (CIS). Tumor surveillance PET/CT scans done between March 2005 and December 2009 of disease free patients after surgery with or without adjuvant chemotherapy for CRC were retrospectively studied. CIS (serial enhanced CT from lung base to pelvis and plain chest radiograph)were performed within 1 month of PET/CT. We excluded patients with distant metastasis on initial staging, a known recurrent tumor, and a lack of follow up imaging. The final diagnosis was based on at least 6 months of follow up with colonoscopy, biopsy, and serial imaging studies in combination with carcinoembryonic antigen levels. A total of 262 PET/CT scans of 245 patients were included. Local and distant recurrences were detected in 27 cases (10.3%). On case based analysis, the overall sensitivity, specificity, and accuracy were 100, 97.0, and 97.3% for PET/CT and 85.1, 97.0, and 95.8% for CIS, respectively. On lesion based analysis, PET/CT detected more lesions compared to CIS in local recurrence and lung metastasis. PET/CT and CIS detected the same number of lesions in abdominal lymph nodes, hepatic metastasis, and peritoneal carcinomatosis. PET/CT detected two more metachronous tumors than did CIS in the lung and thyroid gland. PET/CT detected more recurrences in patients who underwent surgery for CRC than did CIS and had the additional advantage of evaluating the entire body during a single scan.

  8. CT coronary angiography versus conventional invasive coronary angiography. The view of the referring physician

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, Martin H. [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Radiology; Universitaetsspital Bern (Switzerland). Dept. fuer Diagnostische, Interventionelle und Paediatrische Radiologie; Zimmermann, E.; Hamm, B. [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Radiology; Dewey, M.

    2014-12-15

    Assessment of experience gained by local referring physicians with the procedure of coronary computed tomographic angiography (CCTA) in the everyday clinical routine. A 25-item questionnaire was sent to 179 physicians, who together had referred a total of 1986 patients for CCTA. They were asked about their experience to date with CCTA, the indications for coronary imaging, and their practice in referring patients for noninvasive CCTA or invasive catheter angiography. 53 questionnaires (30%) were assessable, corresponding to more than 72% of the patients referred. Of the referring physicians who responded, 94% saw a concrete advantage of CCTA in the treatment of patients, whereby 87% were 'satisfied' or 'very satisfied' with the reporting. For excluding coronary heart disease (CHD) where there was a low pre-test probability of disease, the physicians considered CCTA to be superior to conventional coronary diagnosis (4.2 on a scale of 1-5) and vice versa for acute coronary syndrome (1.6 of 5). The main reasons for unsuitability of CCTA for CT diagnosis were claustrophobia and the absence of a sinus rhythm. The level of exposure to radiation in CCTA was estimated correctly by only 42% of the referring physicians. 90% of the physicians reported that their patients evaluated their coronary CT overall as 'positive' or 'neutral', while 87% of the physicians whose patients had undergone both procedures reported that the patients had experienced CCTA as the less disagreeable of the two. CCTA is accepted by the referring physicians as an alternative imaging procedure for the exclusion of CHD and received a predominantly positive assessment from both the referring physicians and the patients.

  9. Radiation dose exposure for lumbar spine epidural steroid injections: a comparison of conventional fluoroscopy data and CT fluoroscopy techniques.

    Science.gov (United States)

    Hoang, Jenny K; Yoshizumi, Terry T; Toncheva, Greta; Gray, Linda; Gafton, Andreia R; Huh, Billy K; Eastwood, James D; Lascola, Christopher D; Hurwitz, Lynne M

    2011-10-01

    The purpose of this article is to compare the radiation dose of conventional fluoroscopy-guided lumbar epidural steroid injections (ESIs) and CT fluoroscopy (CTF)-guided lumbar ESI using both clinical data and anthropomorphic phantoms. We performed a retrospective review of dose parameters for 14 conventional fluoroscopy ESI procedures performed by one proceduralist and 42 CTF-guided ESIs performed by three proceduralists (14 each). By use of imaging techniques similar to those for our clinical cohorts, a commercially available anthropomorphic male phantom with metal oxide semiconductor field effect transistor detectors was scanned to obtain absorbed organ doses for conventional fluoroscopy-guided and CTF-guided ESIs. Effective dose (ED) was calculated from measured organ doses. The mean conventional fluoroscopy time for ESI was 37 seconds, and the mean procedural CTF time was 4.7 seconds. Calculated ED for conventional fluoroscopy was 0.85 mSv compared with 0.45 mSv for CTF. The greatest contribution to the radiation dose from CTF-guided ESI came from the planning lumbar spine CT scan, which had an ED of 2.90 mSv when z-axis ranged from L2 to S1. This resulted in a total ED for CTF-guided ESI (lumbar spine CT scan plus CTF) of 3.35 mSv. The ED for the CTF-guided ESI was almost half that of conventional fluoroscopy because of the shorter fluoroscopy time. However, the overall radiation dose for CTF-guided ESIs can be up to four times higher when a full diagnostic lumbar CT scan is performed as part of the procedure. Radiation dose reduction for CTF-guided ESI is best achieved by minimizing the dose from the preliminary planning lumbar spine CT scan.

  10. An assessment of the iPad 2 as a CT teleradiology tool using brain CT with subtle intracranial hemorrhage under conventional illumination.

    Science.gov (United States)

    Park, Joon Bum; Choi, Hyuk Joong; Lee, Jeong Hun; Kang, Bo Seung

    2013-08-01

    We examined the potential of the iPad 2 as a teleradiologic tool for evaluating brain computed tomography (CT) with subtle hemorrhage in the conventional lighting conditions which are common situations in the remote CT reading. The comparison of the clinician's performance was undertaken through detecting hemorrhage by the iPad 2 and the clinical liquid crystal display (LCD) monitor. We selected 100 brain CT exams performed for head trauma or headache. Fifty had subtle radiological signs of intracranial hemorrhage (ICH), while the other 50 showed no significant abnormality. Five emergency medicine physicians reviewed these brain CT scans using the iPad 2 and the LCD monitor, scoring the probability of ICH on each exam on a five-point scale. Result showed high sensitivities and specificities in both devices. We generated receiver operating characteristic curves and calculated the average area under the curve of the iPad 2 and the LCD (0.935 and 0.900). Using the iPad 2 and reliable internet connectivity, clinicians can provide remote evaluation of brain CT with subtle hemorrhage under suboptimal viewing condition. Considering the distinct advantages of the iPad 2, the popular out-of-hospital use of mobile CT teleradiology would be anticipated soon.

  11. Acceptability of virtual unenhanced CT of the aorta as a replacement for the conventional unenhanced phase

    Energy Technology Data Exchange (ETDEWEB)

    Shaida, N., E-mail: nadeem.shaida@addenbrookes.nhs.uk [Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom); Bowden, D.J.; Barrett, T.; Godfrey, E.M.; Taylor, A.; Winterbottom, A.P.; See, T.C. [Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom); Lomas, D.J. [Department of Radiology, University of Cambridge, Addenbrooke' s Hospital, Cambridge (United Kingdom); Shaw, A.S. [Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)

    2012-05-15

    Aim: To evaluate whether virtual unenhanced (VU) computed tomography (CT) images generated of the aorta were of sufficient quality to replace the conventional unenhanced (CU) images. Materials and methods: Forty-nine patients undergoing examination of the thoracic or abdominal aorta were examined using a dual-energy protocol. VU images were generated from the arterial phase images and compared to the CU images. Objective analysis was performed by drawing paired regions of interest (ROIs) within the thoracic and abdominal aorta and measuring the radiodensity in Hounsfield units attenuation within the ROIs. Subjective analysis was performed by two experienced readers evaluating the VU images in terms of noise, quality, calcium loss, and overall acceptability. Results: The attenuation was significantly higher in the VU images compared to the CU images within the thoracic aorta (p < 0.01) but not within the abdominal aorta (p = 0.15). Overall the VU images of the abdominal aorta were deemed acceptable as replacements for the CU images in 93% of cases. For the thoracic aorta, the VU images were deemed acceptable in only 12% of cases, primarily due to pulsation artefact. Conclusion: VU images of the abdominal aorta are acceptable as replacements for the CU images in the vast majority of cases; however, they are not suitable as replacements for the CU images of the thoracic aorta.

  12. {sup 18}F-FDG PET/CT compared to conventional imaging modalities in pediatric primary bone tumors

    Energy Technology Data Exchange (ETDEWEB)

    London, Kevin [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Discipline of Paediatrics and Child Health, Sydney Medical School, Sydney, NSW (Australia); Stege, Claudia; Kaspers, Gertjan [VU Medical Centre, Divisions of Paediatric Oncology/Haematology, Amsterdam (Netherlands); Cross, Siobhan; Dalla-Pozza, Luciano [The Children' s Hospital at Westmead, Department of Oncology, Sydney (Australia); Onikul, Ella [The Children' s Hospital at Westmead, Department of Medical Imaging, Sydney (Australia); Graf, Nicole [The Children' s Hospital at Westmead, Department of Pathology, Sydney (Australia); Howman-Giles, Robert [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Discipline of Imaging, Sydney Medical School, Sydney, NSW (Australia)

    2012-04-15

    F-Fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) is useful in adults with primary bone tumors. Limited published data exist in children. To compare hybrid FDG positron emission tomography/computed tomography (PET/CT) with conventional imaging (CI) modalities in detecting malignant lesions, predicting response to chemotherapy and diagnosing physeal involvement in pediatric primary bone tumors. Retrospective analysis of PET/CT and CI reports with histopathology or follow-up > 6 months as reference standard. Response parameters and physeal involvement at diagnosis were compared to histopathology. A total of 314 lesions were detected in 86 scans. Excluding lung lesions, PET/CT had higher sensitivity and specificity than CI (83%, 98% and 78%, 97%, respectively). In lung lesions, PET/CT had higher specificity than CI (96% compared to 87%) but lower sensitivity (80% compared to 93%). Higher initial SUV{sub max} and greater SUV{sub max} reduction on PET/CT after chemotherapy predicted a good response. Change in tumor size on MRI did not predict response. Both PET/CT and MRI were very sensitive but of low specificity in predicting physeal tumor involvement. PET/CT appears more accurate than CI in detecting malignant lesions in childhood primary bone tumors, excluding lung lesions. It seems better than MRI at predicting tumor response to chemotherapy. (orig.)

  13. Diagnostic imaging of Klippel-Feil syndrome: conventional radiography, CT and MR imaging. Case report; Bildgebende Diagnostik des Klippel-Feil-Syndroms: Konventionelle Roentgenaufnahmen, CT und MRT. Fallbericht

    Energy Technology Data Exchange (ETDEWEB)

    Jochens, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schubeus, P. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Steinkamp, H.J. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Menzhausen, L. [Abt. fuer Psychiatrie, Urban Krankenhaus, Berlin (Germany); Felix, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1993-12-31

    In two patients with Klippel-Feil syndrome, type II radiographic findings of the malformation are shown in the cervical spine and the craniocervical junction. Conventional X-rays of the cervical spine in the AP and lateral view and conventional tomography as well as CT of the cervical spine were obtained in both patients. One of the two patients additionally underwent MR imaging. Findings of the different imaging modalities are compared with each other. (orig.) [Deutsch] Anhand von zwei Patienten mit Klippel-Feil-Syndrom Typ II werden typische radiologische Befunde des Missbildungssyndroms im Bereich der Halswirbelsaeule und des kraniozervikalen Ueberganges dargestellt. Neben den konventionellen HWS-Roentgenaufnahmen und den konventionellen Schichtaufnahmen, wurden bei beiden Patienten ein CT der HWS und bei einem Patienten zusaetzlich ein MRT durchgefuehrt. Die Ergebnisse und Befunde der verschiedenen Untersuchungsverfahren werden einander gegenuebergestellt. (orig.)

  14. Full Scale Earth Fault Experiments on 10 kV laboratory network with comparative Measurements on Conventional CT's and VT's

    DEFF Research Database (Denmark)

    Sørensen, Stefan; Nielsen, Hans Ove; Bak-Jensen, Birgitte

    2002-01-01

    . The necessity of high bandwidth measurement equipment for earth fault measurements on compensated distribution networks can be undermined, since it will be shown that the transient signal transfer through conventional CT?s and VT?s for further signal analysis is sufficient. Caused the inadequacy three phase...... transformers (CT?s) and voltage transformers (VT?s) by an optical link. Comparison with a similar earlier performed experiment caried out autumn 1998, where current and voltage measurements were measured with high bandwidth Rugowski-coils and high voltage Tektronix probes, gave remarkable results...

  15. Standardised uptake values from PET/CT images: comparison with conventional attenuation-corrected PET

    Energy Technology Data Exchange (ETDEWEB)

    Souvatzoglou, M.; Ziegler, S.I.; Martinez, M.J.; Dzewas, G.; Schwaiger, M.; Bengel, F. [Nuklearmedizinische Klinik der Technischen Universitaet Muenchen, Munich (Germany); Busch, R. [Institut fuer Epidemiologie und Statistik der Technischen Universitaet Muenchen, Munich (Germany)

    2007-03-15

    In PET/CT, CT-derived attenuation factors may influence standardised uptake values (SUVs) in tumour lesions and organs when compared with stand-alone PET. Therefore, we compared PET/CT-derived SUVs intra-individually in various organs and tumour lesions with stand-alone PET-derived SUVs. Thirty-five patients with known or suspected cancer were prospectively included. Sixteen patients underwent FDG PET using an ECAT HR+scanner, and subsequently a second scan using a Biograph Sensation 16PET/CT scanner. Nineteen patients were scanned in the reverse order. All images were reconstructed with an iterative algorithm (OSEM). Suspected lesions were grouped as paradiaphragmatic versus distant from the diaphragm. Mean and maximum SUVs were also calculated for brain, lung, liver, spleen and vertebral bone. The attenuation coefficients ({mu} values) used for correction of emission data (bone, soft tissue, lung) in the two data sets were determined. A body phantom containing six hot spheres and one cold cylinder was measured using the same protocol as in patients. Forty-six lesions were identified. There was a significant correlation of maximum and mean SUVs derived from PET and PET/CT for 14 paradiaphragmatic lesions (r=0.97 respectively; p<0.001 respectively) and for 32 lesions located distant from the diaphragm (r=0.87 and r=0.89 respectively; p<0.001 respectively). No significant differences were observed in the SUVs calculated with PET and PET/CT in the lesions or in the organs. In the phantom, radioactivity concentration in spheres calculated from PET and from PET/CT correlated significantly (r=0.99; p<0.001). SUVs of cancer lesions and normal organs were comparable between PET and PET/CT, supporting the usefulness of PET/CT-derived SUVs for quantification of tumour metabolism. (orig.)

  16. Delayed-Phase Cone-Beam CT Improves Detectability of Intrahepatic Cholangiocarcinoma During Conventional Transarterial Chemoembolization

    Energy Technology Data Exchange (ETDEWEB)

    Schernthaner, Ruediger Egbert [The Johns Hopkins Hospital, Russell H. Morgan Department of Radiology and Radiological Science, Division of Vascular and Interventional Radiology (United States); Lin, MingDe [Philips Research North America, Ultrasound and Interventions (United States); Duran, Rafael; Chapiro, Julius; Wang, Zhijun; Geschwind, Jean-François, E-mail: jfg@jhmi.edu [The Johns Hopkins Hospital, Russell H. Morgan Department of Radiology and Radiological Science, Division of Vascular and Interventional Radiology (United States)

    2015-08-15

    PurposeTo evaluate the detectability of intrahepatic cholangiocarcinoma (ICC) on dual-phase cone-beam CT (DPCBCT) during conventional transarterial chemoembolization (cTACE) compared to that of digital subtraction angiography (DSA) with respect to pre-procedure contrast-enhanced magnetic resonance imaging (CE-MRI) of the liver.MethodsThis retrospective study included 17 consecutive patients (10 male, mean age 64) with ICC who underwent pre-procedure CE-MRI of the liver, and DSA and DPCBCT (early-arterial phase (EAP) and delayed-arterial phase (DAP)) just before cTACE. The visibility of each ICC lesion was graded by two radiologists on a three-rank scale (complete, partial, and none) on DPCBCT and DSA images, and then compared to pre-procedure CE-MRI.ResultsOf 61 ICC lesions, only 45.9 % were depicted by DSA, whereas EAP- and DAP-CBCT yielded a significantly higher detectability rate of 73.8 % and 93.4 %, respectively (p < 0.01). Out of the 33 lesions missed on DSA, 18 (54.5 %) and 30 (90.9 %) were revealed on EAP- and DAP-CBCT images, respectively. DSA depicted only one lesion that was missed by DPCBCT due to streak artifacts caused by a prosthetic mitral valve. DAP-CBCT identified significantly more lesions than EAP-CBCT (p < 0.01). Conversely, EAP-CBCT did not detect lesions missed by DAP-CBCT. For complete lesion visibility, DAP-CBCT yielded significantly higher detectability (78.7 %) compared to EAP (31.1 %) and DSA (21.3 %) (p < 0.01).ConclusionDPCBCT, and especially the DAP-CBCT, significantly improved the detectability of ICC lesions during cTACE compared to DSA. We recommend the routine use of DAP-CBCT in patients with ICC for per-procedure detectability and treatment planning in the setting of TACE.

  17. Patch-based generation of a pseudo CT from conventional MRI sequences for MRI-only radiotherapy of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Andreasen, Daniel, E-mail: dana@dtu.dk [Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby 2800, Denmark and Department of Oncology, Radiotherapy Research Unit, Copenhagen University Hospital, Herlev 2730 (Denmark); Van Leemput, Koen [Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby 2800, Denmark and A.A. Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, Massachusetts 02129 (United States); Hansen, Rasmus H. [Department of Radiology, Copenhagen University Hospital, Herlev 2730 (Denmark); Andersen, Jon A. L.; Edmund, Jens M. [Department of Oncology, Radiotherapy Research Unit, Copenhagen University Hospital, Herlev 2730 (Denmark)

    2015-04-15

    Purpose: In radiotherapy (RT) based on magnetic resonance imaging (MRI) as the only modality, the information on electron density must be derived from the MRI scan by creating a so-called pseudo computed tomography (pCT). This is a nontrivial task, since the voxel-intensities in an MRI scan are not uniquely related to electron density. To solve the task, voxel-based or atlas-based models have typically been used. The voxel-based models require a specialized dual ultrashort echo time MRI sequence for bone visualization and the atlas-based models require deformable registrations of conventional MRI scans. In this study, we investigate the potential of a patch-based method for creating a pCT based on conventional T{sub 1}-weighted MRI scans without using deformable registrations. We compare this method against two state-of-the-art methods within the voxel-based and atlas-based categories. Methods: The data consisted of CT and MRI scans of five cranial RT patients. To compare the performance of the different methods, a nested cross validation was done to find optimal model parameters for all the methods. Voxel-wise and geometric evaluations of the pCTs were done. Furthermore, a radiologic evaluation based on water equivalent path lengths was carried out, comparing the upper hemisphere of the head in the pCT and the real CT. Finally, the dosimetric accuracy was tested and compared for a photon treatment plan. Results: The pCTs produced with the patch-based method had the best voxel-wise, geometric, and radiologic agreement with the real CT, closely followed by the atlas-based method. In terms of the dosimetric accuracy, the patch-based method had average deviations of less than 0.5% in measures related to target coverage. Conclusions: We showed that a patch-based method could generate an accurate pCT based on conventional T{sub 1}-weighted MRI sequences and without deformable registrations. In our evaluations, the method performed better than existing voxel-based and

  18. {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.)

  19. [CT and MR virtual colonscopy: indications, limits and comparison with conventional colonscopy].

    Science.gov (United States)

    Bertini, L; Campagnano, S; Lanciotti, S; Fiorello, S; Fabiani, B; Graziani, M G; Gualdi, G F

    2006-01-01

    Virtual endoscopy is a new method for studying the colon; it consists in acquisition of CT and MR images and to elaborate them with a workstation, to create endoluminal vision as like as traditional colonscopy, permitting the complete exploration of colonic lumen, also with stenotic tumors. The analysis of the differences between CT and MR colography shows like these two techniques present both advantages and disadvantages, such as the impossibility to perform MR in patients with pace-maker or in claustrophobic patients and the impossibility to perform CT with iodated agents in patients with renal failure or with a story of adverse reactions. The increased use of these techniques is due to the high sensitivity of last-generation CT and MR machine, to the increased spatial resolution, to specific softwares for digital cleaning of colon, to the introduction of high-end workstations and to the possibility of computed assisted diagnosis (CAD). So, it is desiderable that the increasing spread of multidetector CT devices and the future technical innovations, should have the effect to increase culture and experience in various diagnostic centers about CT-colography, making possible the spreading of virtual endoscopy as a screening tool.

  20. 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.

  1. Colonography by CT,MRI and PET/CT combined with conventional colonoscopy in colorectal cancer screening and staging

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Colorectal cancer(CRC)remains a leading cancer killer worldwide.But the disease is both curable and preventable at an early stage.Regular CRC cancer screening has been shown to reduce the risk of dying from CRC.However,the importance of large-scale screening is only now starting to be appreciated.This article reviews a variety of imaging procedures available for detecting ulcerative colitis(UC)and Crohn's disease (CD),polyps and CRC in their early stage and also presents details on various screening options.Detecting,staging and re-staging of patients with CRC also require multimodality,multistep imaging approaches.Staging and re-staging with conventional colonoscopy(CC),computer tomography colonography(CTC),magnetic resonance colonography(MRC)and positron emission tomography/computer tomography colonography(PET/CTC)are of paramount importance in determining the most appropriate therapeutic method and in predicting the risk of tumor recurrence and overall prognosis.The advantages and limitations of these modalities are also discussed.

  2. Whole-tumor perfusion CT in patients with advanced lung adenocarcinoma treated with conventional and antiangiogenetic chemotherapy: initial experience.

    Science.gov (United States)

    Fraioli, Francesco; Anzidei, Michele; Zaccagna, Fulvio; Mennini, Maria Luisa; Serra, Goffredo; Gori, Bruno; Longo, Flavia; Catalano, Carlo; Passariello, Roberto

    2011-05-01

    To determine whether wide-volume perfusion computed tomography (CT) performed with a new generation scanner can allow evaluation of the effects of chemotherapy combined with antiangiogenetic treatment on the whole tumor mass in patients with locally advanced lung adenocarcinoma and to determine if changes in CT numbers correlate with the response to therapy as assessed by conventional response evaluation criteria in solid tumors (RECIST). Forty-five patients with unresectable lung adenocarcinoma underwent perfusion CT before and 40 and 90 days after chemotherapy and antiangiogenetic treatment. RECIST measurements and calculations of blood flow, blood volume, time to peak, and permeability were performed by two independent blinded radiologists. Pearson correlation coefficient was used to assess the correlation between baseline CT numbers. Baseline and follow-up perfusion parameters of the neoplastic lesions were tested overall for statistically significant differences by using the repeated-measures analysis of variance and then were also compared on the basis of the therapy response assessed according to the RECIST criteria. Pearson correlation coefficient showed a significant correlation between baseline values of blood flow and blood volume (ρ = 0.48; P = .001), time to peak and permeability (ρ = 0.31; P = .04), time to peak and blood flow (ρ = -0.66; P < .001), and time to peak and blood volume (ρ = -0.39; P = .007). Blood flow, blood volume, and permeability values were higher in responding patients than in the other patients, with a significant difference at second follow-up for blood flow (P = .0001), blood volume (P = .02), and permeability (P = .0001); time to peak was higher in nonresponding patients (P = .012). Perfusion CT imaging may allow evaluation of lung cancer angiogenesis demonstrating alterations in vascularity following treatment. RSNA, 2011

  3. Evaluation of conventional imaging performance in a research whole-body CT system with a photon-counting detector array

    Science.gov (United States)

    Yu, Zhicong; Leng, Shuai; Jorgensen, Steven M.; Li, Zhoubo; Gutjahr, Ralf; Chen, Baiyu; Halaweish, Ahmed F.; Kappler, Steffen; Yu, Lifeng; Ritman, Erik L.; McCollough, Cynthia H.

    2016-02-01

    This study evaluated the conventional imaging performance of a research whole-body photon-counting CT system and investigated its feasibility for imaging using clinically realistic levels of x-ray photon flux. This research system was built on the platform of a 2nd generation dual-source CT system: one source coupled to an energy integrating detector (EID) and the other coupled to a photon-counting detector (PCD). Phantom studies were conducted to measure CT number accuracy and uniformity for water, CT number energy dependency for high-Z materials, spatial resolution, noise, and contrast-to-noise ratio. The results from the EID and PCD subsystems were compared. The impact of high photon flux, such as pulse pile-up, was assessed by studying the noise-to-tube-current relationship using a neonate water phantom and high x-ray photon flux. Finally, clinical feasibility of the PCD subsystem was investigated using anthropomorphic phantoms, a cadaveric head, and a whole-body cadaver, which were scanned at dose levels equivalent to or higher than those used clinically. Phantom measurements demonstrated that the PCD subsystem provided comparable image quality to the EID subsystem, except that the PCD subsystem provided slightly better longitudinal spatial resolution and about 25% improvement in contrast-to-noise ratio for iodine. The impact of high photon flux was found to be negligible for the PCD subsystem: only subtle high-flux effects were noticed for tube currents higher than 300 mA in images of the neonate water phantom. Results of the anthropomorphic phantom and cadaver scans demonstrated comparable image quality between the EID and PCD subsystems. There were no noticeable ring, streaking, or cupping/capping artifacts in the PCD images. In addition, the PCD subsystem provided spectral information. Our experiments demonstrated that the research whole-body photon-counting CT system is capable of providing clinical image quality at clinically realistic levels of x

  4. Evaluation of conventional imaging performance in a research whole-body CT system with a photon-counting detector array.

    Science.gov (United States)

    Yu, Zhicong; Leng, Shuai; Jorgensen, Steven M; Li, Zhoubo; Gutjahr, Ralf; Chen, Baiyu; Halaweish, Ahmed F; Kappler, Steffen; Yu, Lifeng; Ritman, Erik L; McCollough, Cynthia H

    2016-02-21

    This study evaluated the conventional imaging performance of a research whole-body photon-counting CT system and investigated its feasibility for imaging using clinically realistic levels of x-ray photon flux. This research system was built on the platform of a 2nd generation dual-source CT system: one source coupled to an energy integrating detector (EID) and the other coupled to a photon-counting detector (PCD). Phantom studies were conducted to measure CT number accuracy and uniformity for water, CT number energy dependency for high-Z materials, spatial resolution, noise, and contrast-to-noise ratio. The results from the EID and PCD subsystems were compared. The impact of high photon flux, such as pulse pile-up, was assessed by studying the noise-to-tube-current relationship using a neonate water phantom and high x-ray photon flux. Finally, clinical feasibility of the PCD subsystem was investigated using anthropomorphic phantoms, a cadaveric head, and a whole-body cadaver, which were scanned at dose levels equivalent to or higher than those used clinically. Phantom measurements demonstrated that the PCD subsystem provided comparable image quality to the EID subsystem, except that the PCD subsystem provided slightly better longitudinal spatial resolution and about 25% improvement in contrast-to-noise ratio for iodine. The impact of high photon flux was found to be negligible for the PCD subsystem: only subtle high-flux effects were noticed for tube currents higher than 300 mA in images of the neonate water phantom. Results of the anthropomorphic phantom and cadaver scans demonstrated comparable image quality between the EID and PCD subsystems. There were no noticeable ring, streaking, or cupping/capping artifacts in the PCD images. In addition, the PCD subsystem provided spectral information. Our experiments demonstrated that the research whole-body photon-counting CT system is capable of providing clinical image quality at clinically realistic levels of x

  5. Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Knobloch, Gesine; Hamm, Bernd [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Jost, Gregor; Pietsch, Hubertus [Bayer Healthcare, MR and CT Contrast Media Research, Berlin (Germany); Huppertz, Alexander [Imaging Science Institute Charite - Siemens, Berlin (Germany)

    2014-08-15

    The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting. A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV). The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-CT-derived iodine concentrations correlated with PMB and BV but not with BF. DE-CT allows early treatment monitoring, which correlates with DCE-CT. Superior performance was observed compared to single-energy CE-CT. circle Regorafenib treatment response was evaluated by CT in a rat tumour model. (orig.)

  6. Posttreatment PET/CT Rather Than Interim PET/CT Using Deauville Criteria Predicts Outcome in Pediatric Hodgkin Lymphoma: A Prospective Study Comparing PET/CT with Conventional Imaging.

    Science.gov (United States)

    Bakhshi, Sameer; Bhethanabhotla, Sainath; Kumar, Rakesh; Agarwal, Krishankant; Sharma, Punit; Thulkar, Sanjay; Malhotra, Arun; Dhawan, Deepa; Vishnubhatla, Sreenivas

    2017-04-01

    Data about the significance of (18)F-FDG PET at interim assessment and end of treatment in pediatric Hodgkin lymphoma (HL) are limited. Methods: Patients (≤18 y) with HL were prospectively evaluated with contrast-enhanced CT (CECT) and PET combined with low-dose CT (PET/CT) at baseline, after 2 cycles of chemotherapy, and after completion of treatment. Revised International Working Group (RIW) criteria and Deauville 5 point-scale for response assessment by PET/CT were used. All patients received doxorubicin (Adriamycin), bleomycin, vinblastine, dacarbazine chemotherapy along with involved-field radiotherapy (25 Gy) for early stage (IA, IB, and IIA) and advanced stage (IIB-IV) with bulky disease. Results: Of the 57 enrolled patients, median follow-up was 81.6 mo (range, 11-97.5 mo). Treatment decisions were based on CECT. At baseline, PET/CT versus CECT identified 67 more disease sites; 23 patients (40.3%) were upstaged and of them in 9 patients (39%) upstaging would have affected treatment decision; notably none of these patients relapsed. The specificity of interim PET/CT based on RIW criteria (61.5%) and Deauville criteria (91.4%) for predicting relapse was higher than CECT (40.3%) (P = 0.03 and P interim PET/CT (RIW) response was 93.3 ± 4.1 versus 89.6 ± 3.8 (positive vs. negative scan, respectively; P = 0.44). The specificity of posttreatment PET/CT (Deauville) was 95.7% versus 76.4% by CECT (P = 0.006). Posttreatment PET/CT (Deauville) showed significantly inferior overall survival in patients with positive scan versus negative scan results (66.4 ± 22.5 vs. 94.5 ± 2.0, P = 0.029). Conclusion: Interim PET/CT has better specificity, and use of Deauville criteria further improves it. Escalation of therapy based on interim PET in pediatric HL needs further conclusive evidence to justify its use. Posttreatment PET/CT (Deauville) predicts overall survival and has better specificity in comparison to conventional imaging.

  7. Patch-based generation of a pseudo CT from conventional MRI sequences for MRI-only radiotherapy of the brain

    DEFF Research Database (Denmark)

    Andreasen, Daniel; Van Leemput, Koen; Hansen, Rasmus H.

    2015-01-01

    Purpose: In radiotherapy (RT) based on magnetic resonance imaging (MRI) as the only modality, the information on electron density must be derived from the MRI scan by creating a so-called pseudo computed tomography (pCT). This is a nontrivial task, since the voxel-intensities in an MRI scan are n...... on conventional T1-weighted MRI sequences and without deformable registrations. In our evaluations, the method performed better than existing voxel-based and atlas-based methods and showed a promising potential for RT of the brain based only on MRI....

  8. Cerebral blood volume imaging by flat detector computed tomography in comparison to conventional multislice perfusion CT.

    Science.gov (United States)

    Struffert, Tobias; Deuerling-Zheng, Yu; Kloska, Stephan; Engelhorn, Tobias; Boese, Jan; Zellerhoff, Michael; Schwab, Stefan; Doerfler, Arnd

    2011-04-01

    We tested the hypothesis that Flat Detector computed tomography (FD-CT) with intravenous contrast medium would allow the calculation of whole brain cerebral blood volume (CBV) mapping (FD-CBV) and would correlate with multislice Perfusion CT (PCT). Twenty five patients were investigated with FD-CBV and PCT. Correlation of the CBV maps of both techniques was carried out with measurements from six anatomical regions from both sides of the brain. Mean values of each region and the correlation coefficient were calculated. Bland-Altman analysis was performed to compare the two different imaging techniques. The image and data quality of both PCT and FD-CBV were suitable for evaluation in all patients. The mean CBV values of FD-CBV and PCT showed only minimal differences with overlapping standard deviation. The correlation coefficient was 0.79 (p < 0.01). Bland-Altman analysis showed a mean difference of -0.077 ± 0.48 ml/100 g between FD-CBV and PCT CBV measurements, indicating that FD-CBV values were only slightly lower than those of PCT. CBV mapping with intravenous contrast medium using Flat Detector CT compared favourably with multislice PCT. The ability to assess cerebral perfusion within the angiographic suite may improve the management of ischaemic stroke and evaluation of the efficacy of dedicated therapies.

  9. CT-guided percutaneous lung biopsy: Comparison of conventional CT fluoroscopy to CT fluoroscopy with electromagnetic navigation system in 60 consecutive patients

    Energy Technology Data Exchange (ETDEWEB)

    Grand, David Justin, E-mail: dgrand@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States); Atalay, Michael A., E-mail: matalay@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States); Cronan, John J., E-mail: cronan@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States); Mayo-Smith, William W., E-mail: wmayo-smith@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States); Dupuy, Damian E., E-mail: ddupuy@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States)

    2011-08-15

    Purpose: To determine if use of an electromagnetic navigation system (EMN) decreases radiation dose and procedure time of CT fluoroscopy guided lung biopsy in lesions smaller than 2.5 cm. Materials/methods: 86 consecutive patients with small lung masses (<2.5 cm) were approached. 60 consented and were randomized to undergo biopsy with CT fluoroscopy (CTF) (34 patients) or EMN (26 patients). Technical failure required conversion to CTF in 8/26 EMN patients; 18 patients completed biopsy with EMN. Numerous biopsy parameters were compared as described below. Results: Average fluoroscopy time using CTF was 28.2 s compared to 35.0 s for EMN (p = 0.1). Average radiation dose was 117 mGy using CTF and 123 mGy for EMN (p = 0.7). Average number of needle repositions was 3.7 for CTF and 4.4 for EMN (p = 0.4). Average procedure time was 15 min for CTF and 20 min for EMN (p = 0.01). There were 7 pneumothoracesin the CTF group and 6 pneumothoraces in the EMN group (p = 0.7). One pneumothorax in the CTF group and 3 pneumothoraces in the EMN group required chest tube placement (p = 0.1). One pneumothorax patient in each group required hospital admission. Diagnostic specimens were obtained in 31/34 patients in the CTF group and 22/26 patients in the EMN group (p = 0.4). Conclusions: EMN was not statistically different than CTF for fluoroscopy time, radiation dose, number of needle repositions, incidence of pneumothorax, need for chest tube, or diagnostic yield. Procedure time was increased with EMN.

  10. Variability of Image Features Computed from Conventional and Respiratory-Gated PET/CT Images of Lung Cancer

    Directory of Open Access Journals (Sweden)

    Jasmine A. Oliver

    2015-12-01

    Full Text Available Radiomics is being explored for potential applications in radiation therapy. How various imaging protocols affect quantitative image features is currently a highly active area of research. To assess the variability of image features derived from conventional [three-dimensional (3D] and respiratory-gated (RG positron emission tomography (PET/computed tomography (CT images of lung cancer patients, image features were computed from 23 lung cancer patients. Both protocols for each patient were acquired during the same imaging session. PET tumor volumes were segmented using an adaptive technique which accounted for background. CT tumor volumes were delineated with a commercial segmentation tool. Using RG PET images, the tumor center of mass motion, length, and rotation were calculated. Fifty-six image features were extracted from all images consisting of shape descriptors, first-order features, and second-order texture features. Overall, 26.6% and 26.2% of total features demonstrated less than 5% difference between 3D and RG protocols for CT and PET, respectively. Between 10 RG phases in PET, 53.4% of features demonstrated percent differences less than 5%. The features with least variability for PET were sphericity, spherical disproportion, entropy (first and second order, sum entropy, information measure of correlation 2, Short Run Emphasis (SRE, Long Run Emphasis (LRE, and Run Percentage (RPC; and those for CT were minimum intensity, mean intensity, Root Mean Square (RMS, Short Run Emphasis (SRE, and RPC. Quantitative analysis using a 3D acquisition versus RG acquisition (to reduce the effects of motion provided notably different image feature values. This study suggests that the variability between 3D and RG features is mainly due to the impact of respiratory motion.

  11. Evaluation of percutaneous vertebroplasty in osteoporotic vertebral fractures using a combination of CT fluoroscopy and conventional lateral fluoroscopy; Perkutane Vertebroplastie osteoporosebedingter Wirbelkoerperfrakturen: Erfahrungen mit der CT-Fluoroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Pitton, M.B.; Schneider, J.; Brecher, B.; Herber, S.; Mohr, W.; Thelen, M. [Klinik fuer Radiologie, Universitaetskliniken Mainz (Germany); Drees, P.; Eckardt, A.; Heine, J. [Klinik fuer Orthopaedie, Universitaetskliniken Mainz (Germany)

    2004-07-01

    Purpose: Evaluation of vertebroplasty using a combination of CT-fluoroscopy and conventional lateral fluoroscopy in patients with osteoporotic vertebral fractures. Materials and Methods: Fifty-eight patients (23male, 35 women, age 69.7 {+-} 10.2 years) with painful osteoporotic vertebral fractures were treated with vertebroplasty in conscious sedation and local anesthesia. Spiral-CT with sagittal reconstructions of the respective vertebral bodies was used for classification of the fracture. The cannula was placed under CT-guidance in the ventral third of the respective vertebral bodies and cement instilled under CT fluoroscopy and lateral fluoroscopy. When cement migrated towards the vertebral canal, the injection was immediately stopped for 30-60 seconds. After polymerization in this location, the injection was continued until sufficient filling of the vertebra. Results were documented by spiral CT with sagittal reconstructions. Results: A total of 123 vertebral bodies were treated, comprising 39 thoracic and 84 lumbar vertebral bodies, with a mean of 2.1 {+-} 1.3 (range 1 to 6) vertebral bodies in each patient and a maximum of 3 vertebral bodies per session. All interventions were successfully completed in conscious sedation and local anesthesia. A mean volume of 5.9 {+-} 0.6 ml (range 2 to 14 ml) cement was applied for each vertebra, with 79.7% of procedures performed using a unilateral access. To achieve a sufficient cement deposit, a bilateral access was used in 20.3%. The dorsal wall of the vertebra was included in 23.6% of the fractures. In one case, cement migration into the spinal canal was detected, reducing the diameter of the canal by 30%. In two other cases, cement leakage was seen at the puncture site of the vertebra (one intercostotransversally in the 10{sup th} thoracic vertebra and one dorsolaterally in the 1{sup st} lumbar vertebra) with retrograde cement migration through the neuroforamen into the epidural space. In one of these cases, the

  12. A method for semi-automatic segmentation and evaluation of intracranial aneurysms in bone-subtraction computed tomography angiography (BSCTA) images

    Science.gov (United States)

    Krämer, Susanne; Ditt, Hendrik; Biermann, Christina; Lell, Michael; Keller, Jörg

    2009-02-01

    The rupture of an intracranial aneurysm has dramatic consequences for the patient. Hence early detection of unruptured aneurysms is of paramount importance. Bone-subtraction computed tomography angiography (BSCTA) has proven to be a powerful tool for detection of aneurysms in particular those located close to the skull base. Most aneurysms though are chance findings in BSCTA scans performed for other reasons. Therefore it is highly desirable to have techniques operating on standard BSCTA scans available which assist radiologists and surgeons in evaluation of intracranial aneurysms. In this paper we present a semi-automatic method for segmentation and assessment of intracranial aneurysms. The only user-interaction required is placement of a marker into the vascular malformation. Termination ensues automatically as soon as the segmentation reaches the vessels which feed the aneurysm. The algorithm is derived from an adaptive region-growing which employs a growth gradient as criterion for termination. Based on this segmentation values of high clinical and prognostic significance, such as volume, minimum and maximum diameter as well as surface of the aneurysm, are calculated automatically. the segmentation itself as well as the calculated diameters are visualised. Further segmentation of the adjoining vessels provides the means for visualisation of the topographical situation of vascular structures associated to the aneurysm. A stereolithographic mesh (STL) can be derived from the surface of the segmented volume. STL together with parameters like the resiliency of vascular wall tissue provide for an accurate wall model of the aneurysm and its associated vascular structures. Consequently the haemodynamic situation in the aneurysm itself and close to it can be assessed by flow modelling. Significant values of haemodynamics such as pressure onto the vascular wall, wall shear stress or pathlines of the blood flow can be computed. Additionally a dynamic flow model can be

  13. (68)Ga-DOTATATE PET/CT in recurrent medullary thyroid carcinoma: a lesion-by-lesion comparison with (111)In-octreotide SPECT/CT and conventional imaging.

    Science.gov (United States)

    Yamaga, Lilian Yuri Itaya; Cunha, Marcelo L; Campos Neto, Guilherme C; Garcia, Marcio R T; Yang, Ji H; Camacho, Cleber P; Wagner, Jairo; Funari, Marcelo B G

    2017-09-01

    The aim of this study was to prospectively compare the detection rate of (68)Ga-DOTATATE PET-CT with (111)In-octreotide SPECT-CT and conventional imaging (CI) in medullary thyroid carcinoma (MTC) patients with increased calcitonin (Ctn) levels but negative CI after thyroidectomy. Fifteen patients with raised Ctn levels and/or CI evidence of recurrence underwent (68)Ga-DOTATATE PET-CT, (111)In-octreotide SPECT-CT and CI. Histopathology, CI and biochemical/clinical/imaging follow-up were used as the reference standard. PET/CT, SPECT/CT and CI were compared in a lesion-based and organ-based analysis. PET/CT evidenced recurrence in 14 of 15 patients. There were 13 true positive (TP), 1 true negative (TN), 1 false positive (FP) and no false negative (FN) cases, resulting in a sensitivity and accuracy of 100% and 93%. SPECT/CT was positive in 6 of 15 cases. There were 6 TP, 2 TN, 7 FN and no FP cases, resulting in a sensitivity of 46% and accuracy of 53%. CI procedures detected tumor lesions in 14 of 15 patients. There were 13 TP, 1TN, 1 FP and no FN cases with a sensitivity of 100% and accuracy of 93%. A significantly higher number of lesions was detected by PET/CT (112 lesions, p = 0.005) and CI (109 lesions, p = 0.005) in comparison to SPECT/CT (16 lesions). There was no significant difference between PET/CT and CI for the total number of detected lesions (p = 0.734). PET/CT detected more lesions than SPECT/CT regardless of the organ. PET/CT detected more bone lesions but missed some neck nodal metastases evidenced by CI. The number of lesions per region demonstrated by PET/CT and CI were similar in the other sites. (68)Ga-DOTATATE PET/CT is superior to (111)In-octreotide SPECT/CT for the detection of recurrent MTC demonstrating a significantly higher number of lesions. (68)Ga-DOTATATE PET/CT showed a superior detection rate compared to CI in demonstrating bone metastases.

  14. Direct comparison of conventional radiography and cone-beam CT in small bone and joint trauma

    Energy Technology Data Exchange (ETDEWEB)

    Smet, E. de [Antwerp University Hospital, Department of Radiology, Edegem (Belgium); Praeter, G. de [Sint-Maartenziekenhuis, Department of Radiology, Duffel (Belgium); Verstraete, K.L.A. [Ghent University Hospital, Department of Radiology, Ghent (Belgium); Wouters, K. [Antwerp University Hospital, Department of Scientific Coordination and Biostatistics, Edegem (Belgium); Beuckeleer, Luc de [GZA Sint-Augustinus, Department of Radiology, Wilrijk (Belgium); Vanhoenacker, F.M.H.M. [Antwerp University Hospital, Department of Radiology, Edegem (Belgium); Sint-Maartenziekenhuis, Department of Radiology, Duffel (Belgium); Ghent University Hospital, Department of Radiology, Ghent (Belgium)

    2015-08-15

    To compare the diagnostic value of cone-beam computed tomography (CBCT) and conventional radiography (CR) after acute small bone or joint trauma. Between March 2013 and January 2014, 231 patients with recent small bone or joint trauma underwent CR and subsequent CBCT. CR and CBCT examinations were independently assessed by two readers, blinded to the result of the other modality. The total number of fractures as well as the number of complex fractures were compared, and inter- and intraobserver agreement for CBCT was calculated. In addition, radiation doses and evaluation times for both modalities were noted and statistically compared. Fracture detection on CBCT increased by 35 % and 37 % for reader 1 and reader 2, respectively, and identification of complex fractures increased by 236 % and 185 %. Interobserver agreement for CBCT was almost perfect, as was intraobserver agreement for reader 1. The intraobserver agreement for reader 2 was substantial. Radiation doses and evaluation time were significantly higher for CBCT. CBCT detects significantly more small bone and joint fractures, in particular complex fractures, than CR. In the majority of cases, the clinical implication of the additionally detected fractures is limited, but in some patients (e.g., fracture-dislocations), the management is significantly influenced by these findings. As the radiation dose for CBCT substantially exceeds that of CR, we suggest adhering to CR as the first-line examination after small bone and joint trauma and keeping CBCT for patients with clinical-radiographic discordance or suspected complex fractures in need of further (preoperative) assessment. (orig.)

  15. {sup 18}F-FDG PET/CT provides powerful prognostic stratification in the primary staging of large breast cancer when compared with conventional explorations

    Energy Technology Data Exchange (ETDEWEB)

    Cochet, Alexandre [Centre Georges-Francois Leclerc, Department of Nuclear Medicine, Dijon Cedex (France); Le2i UMR CNRS 6306, Dijon (France); Dygai-Cochet, Inna; Riedinger, Jean-Marc; Berriolo-Riedinger, Alina; Toubeau, Michel [Centre Georges-Francois Leclerc, Department of Nuclear Medicine, Dijon Cedex (France); Humbert, Olivier; Brunotte, Francois [Centre Georges-Francois Leclerc, Department of Nuclear Medicine, Dijon Cedex (France); Le2i UMR CNRS 6306, Dijon (France); CHU Dijon, MRI and Spectroscopy Unit, Dijon (France); Guiu, Severine; Coudert, Bruno [Centre Georges-Francois Leclerc, Department of Oncology, Dijon (France); Coutant, Charles; Fumoleau, Pierre [Centre Georges-Francois Leclerc, Department of Surgery, Dijon (France)

    2014-03-15

    The objective of this study was to assess the impact on management and the prognostic value of {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT for initial staging of newly diagnosed large breast cancer (BC) when compared with conventional staging. We prospectively included 142 patients with newly diagnosed BC and at least grade T2 tumour. All patients were evaluated with complete conventional imaging (CI) procedures (mammogram and/or breast ultrasound, bone scan, abdominal ultrasound and/or CT, X-rays and/or CT of the chest), followed by FDG PET/CT exploration, prior to treatment. The treatment plan based on CI staging was compared with that based on PET/CT findings. CI and PET/CT findings were confirmed by imaging and clinical follow-up and/or pathology when assessable. Progression-free survival (PFS) was analysed using the Cox proportional hazards regression model. According to CI staging, 79 patients (56 %) were stage II, 46 (32 %) stage III and 17 (12 %) stage IV (distant metastases). Of the patients, 30 (21 %) were upstaged by PET/CT, including 12 (8 %) from stage II or III to stage IV. On the other hand, 23 patients (16 %) were downstaged by PET/CT, including 4 (3 %) from stage IV to stage II or III. PET/CT had a high or medium impact on management planning for 18 patients (13 %). Median follow-up was 30 months (range 9-59 months); 37 patients (26 %) experienced recurrence or progression of disease during follow-up and 17 patients (12 %) died. The Cox model indicated that CI staging was significantly associated with PFS (p = 0.01), but PET/CT staging provided stronger prognostic stratification (p < 0.0001). Moreover, Cox regression multivariate analysis showed that only PET/CT staging remained associated with PFS (p < 0.0001). FDG PET/CT provides staging information that more accurately stratifies prognostic risk in newly diagnosed large BC when compared with conventional explorations alone. (orig.)

  16. Preliminary clinical experience with a dedicated interventional robotic system for CT-guided biopsies of lung lesions: a comparison with the conventional manual technique.

    Science.gov (United States)

    Anzidei, Michele; Argirò, Renato; Porfiri, Andrea; Boni, Fabrizio; Anile, Marco; Zaccagna, Fulvio; Vitolo, Domenico; Saba, Luca; Napoli, Alessandro; Leonardi, Andrea; Longo, Flavia; Venuta, Federico; Bezzi, Mario; Catalano, Carlo

    2015-05-01

    Evaluate the performance of a robotic system for CT-guided lung biopsy in comparison to the conventional manual technique. One hundred patients referred for CT-guided lung biopsy were randomly assigned to group A (robot-assisted procedure) or group B (conventional procedure). Size, distance from entry point and position in lung of target lesions were evaluated to assess homogeneity differences between the two groups. Procedure duration, dose length product (DLP), precision of needle positioning, diagnostic performance of the biopsy and rate of complications were evaluated to assess the clinical performance of the robotic system as compared to the conventional technique. All biopsies were successfully performed. The size (p = 0.41), distance from entry point (p = 0.86) and position in lung (p = 0.32) of target lesions were similar in both groups (p = 0.05). Procedure duration and radiation dose were significantly reduced in group A as compared to group B (p = 0.001). Precision of needle positioning, diagnostic performance of the biopsy and rate of complications were similar in both groups (p = 0.05). Robot-assisted CT-guided lung biopsy can be performed safely and with high diagnostic accuracy, reducing procedure duration and radiation dose in comparison to the conventional manual technique. • CT-guided biopsy is the main procedure to obtain diagnosis in lung tumours. • The robotic device facilitates percutaneous needle placement under CT guidance. • Robot-assisted CT-guided lung biopsy reduces procedure duration and radiation dose.

  17. Parametric response mapping of dynamic CT for predicting intrahepatic recurrence of hepatocellular carcinoma after conventional transcatheter arterial chemoembolization

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung Joon; Kim, Hyung Sik [Gachon University Gil Hospital, Department of Radiology, Incheon (Korea, Republic of); Kim, Jonghoon [Sungkyunkwan University, Department of Electronic Electrical and Computer Engineering, Suwon (Korea, Republic of); Seo, Jongbum [Yonsei University, Department of Biomedical Engineering, Wonju (Korea, Republic of); Lee, Jong-min [Hanyang University, Department of Biomedical Engineering, Seoul (Korea, Republic of); Park, Hyunjin [Sungkyunwkan University, School of Electronic and Electrical Engineering, Suwon (Korea, Republic of)

    2016-01-15

    The aim of our study was to determine the diagnostic value of a novel image analysis method called parametric response mapping (PRM) for prediction of intrahepatic recurrence of hepatocellular carcinoma (HCC) treated with conventional transcatheter arterial chemoembolization (TACE). This retrospective study was approved by the IRB. We recruited 55 HCC patients who achieved complete remission (CR) after TACE and received longitudinal multiphasic liver computed tomography (CT). The patients fell into two groups: the recurrent tumour group (n = 29) and the non-recurrent tumour group (n = 26). We applied the PRM analysis to see if this technique could distinguish between the two groups. The results of the PRM analysis were incorporated into a prediction algorithm. We retrospectively removed data from the last time point and attempted to predict the response to therapy of the removed data. The PRM analysis was able to distinguish between the non-recurrent and recurrent groups successfully. The prediction algorithm detected response to therapy with an area under the curve (AUC) of 0.76, while the manual approach had AUC 0.64. Adopting PRM analysis can potentially distinguish between recurrent and non-recurrent HCCs and allow for prediction of response to therapy after TACE. (orig.)

  18. Diagnostic Performance of F-18 FDG PET/CT in Patients with Cancer of Unknown Primary: Additional Benefit over CT-Based Conventional Work up

    Directory of Open Access Journals (Sweden)

    Mehrdad Bakhshayeshkaram

    2016-01-01

    Full Text Available Background: In the era of well-developed site-specific treatment strategies in cancer, identification of occult primary is of paramount importance in CUP patients. Furthermore, exact determination of the extent of the disease may help in optimizing treatment planning. The aim of the present study was to investigate additional value of F-18 FDG PET/CT in patients with cancer of unknown primary (CUP as an appropriate imaging tool in early phase of initial standard work up.Materials and Methods: Sixty-two newly diagnosed CUP patients with inconclusive diagnostic CT scan of chest, abdomen and pelvis referring for F-18 FDG PET/CT were enrolled in this study. Standard of reference was defined as histopathology, other diagnostic procedures and a 3-month formal clinical follow up. The results of PET/CT were categorized as suggestion for primary site and additional metastasis and classified as true positive, false positive, false negative and true negative. The impact of additional metastasis revealed by F-18 FDG PET/CT on treatment planning and the time contribution of F-18 FDG PET/CT in diagnostic pathway was investigated.Results: Sixty-two patients with mean age of 62 (30 men, 32 women, PET/CT correctly identified primary origin in 32% with false positive rate of 14.8%. No primary lesion was detected after negative PET/CT according to standard of reference. Sensitivity, Specificity and accuracy were 100%, 78% and 85%, respectively. Additional metastatic site was found in 56% with 22% impact on treatment planning. Time contribution for PET/CT was 10% of total diagnostic pathway.Conclusion: Providing higher detection rate of primary origin with excellent diagnostic performance, shortening the diagnostic pathway and improving treatment planning, F-18 FDG PET/CT may play a major role in diagnostic work up of CUP patients and may be recommended as an alternative imaging tool in early phase of investigation.

  19. Diagnostic imaging in polytrauma: comparison of radiation exposure from whole-body MSCT and conventional radiography with organ-specific CT; Radiologische Bildgebung beim Polytrauma: Dosisvergleich von Ganzkoerper-MSCT und konventionellem Roentgen mit organspezifischer CT

    Energy Technology Data Exchange (ETDEWEB)

    Wedegaertner, U.; Lorenzen, M.; Weber, C.; Adam, G. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Nagel, H.D. [Philips Medizin Systeme GmbH, Hamburg (Germany)

    2004-07-01

    Purpose: To compare the radiation dose of whole-body multislice CT (MSCT) and conventional radiography with organ-specific CT in polytrauma. Materials and Methods: The whole-body MSCT encompassing brain, neck and midface, chest, abdomen and pelvis was performed on a Somatom Volume Zoom (Siemens). Conventional radiography consisted of chest and cervical, thoracic and lumbar spine in two views as well as pelvis. Polymat, Siemens. Three combinations of organ specific CT were chosen: CT examination of (1) head and cervical spine, (2) head, cervical spine and chest, (3) head, cervical spine and abdomen. The effective doses of whole-body MSCT and conventional radiography with organ-specific CT were calculated. Results: Effective doses were 20 mSv for whole-body MSCT, 2 mSv for conventional x-ray, and 5 mSv for combination (1), 8 mSv for combination (2) and (3) 16 mSv for combination (3) of the organ-specific CT. The ratio of radiation dose between whole-body MSCT and radiography was 10: 1. This ratio was reduced to 3: 1, 2: 1 and 1: 1 when a combination of radiography and CT was performed. Conclusions: Whole-body MSCT in polytrauma compared to conventional radiography with organ-specific CT induces a threefold increased dose in unfavorable situations and no increased dose in favorable situations. Nevertheless, routine use of whole-body MSCT should be critically evaluated and should be adapted to the clinical benefit. (orig.) [German] Ziel: Dosisvergleich von Ganzkoerper-MSCT und konventioneller Basisdiagnostik mit organspezifischen Ct-Untersuchungen beim Polytrauma. Material und Methoden: Die Ganzkoerper-MSCT-Untersuchung von Schaedel, Mittelgesicht, HWS sowie Thorax, Abdomen und Becken erfolgte an einem Somatom-Volume-Zoom (Siemens). Die konventionelle Bildgebung, bestehend aus Thorax, Becken, HWS, BWS und LWs, wurde an einem Siemens-Polymat durchgefuehrt. Fuer die organspezifischen CT-Untersuchungen wurden 3 Kombinationen ausgewaehlt: (1) CCT + HWS, (2) CCT + HWS

  20. Translation of atherosclerotic plaque phase-contrast CT imaging from synchrotron radiation to a conventional lab-based X-ray source.

    Directory of Open Access Journals (Sweden)

    Tobias Saam

    Full Text Available OBJECTIVES: Phase-contrast imaging is a novel X-ray based technique that provides enhanced soft tissue contrast. The aim of this study was to evaluate the feasibility of visualizing human carotid arteries by grating-based phase-contrast tomography (PC-CT at two different experimental set-ups: (i applying synchrotron radiation and (ii using a conventional X-ray tube. MATERIALS AND METHODS: Five ex-vivo carotid artery specimens were examined with PC-CT either at the European Synchrotron Radiation Facility using a monochromatic X-ray beam (2 specimens; 23 keV; pixel size 5.4 µm, or at a laboratory set-up on a conventional X-ray tube (3 specimens; 35-40 kVp; 70 mA; pixel size 100 µm. Tomographic images were reconstructed and compared to histopathology. Two independent readers determined vessel dimensions and one reader determined signal-to-noise ratios (SNR between PC-CT and absorption images. RESULTS: In total, 51 sections were included in the analysis. Images from both set-ups provided sufficient contrast to differentiate individual vessel layers. All PCI-based measurements strongly predicted but significantly overestimated lumen, intima and vessel wall area for both the synchrotron and the laboratory-based measurements as compared with histology (all p0.53 per mm(2, 95%-CI: 0.35 to 0.70. Although synchrotron-based images were characterized by higher SNRs than laboratory-based images; both PC-CT set-ups had superior SNRs compared to corresponding conventional absorption-based images (p0.98 and >0.84 for synchrotron and for laboratory-based measurements; respectively. CONCLUSION: Experimental PC-CT of carotid specimens is feasible with both synchrotron and conventional X-ray sources, producing high-resolution images suitable for vessel characterization and atherosclerosis research.

  1. Comparison of the diagnostic accuracy of CBCT and conventional CT in detecting degenerative osseous changes of the TMJ: A systematic review

    Directory of Open Access Journals (Sweden)

    Ranjeni Rajamani Veerappan

    2015-01-01

    Full Text Available Temporomandibular joint (TMJ disorders are a group of conditions that cause pain and dysfunction in the jaw joint and muscles that control jaw movement. According to the Research Diagnostic Criteria (RDC/TMD, temporomandibular disorders (TMDs may be classified into three different groups: a myofacial pain dysfunction syndrome (MPDS, b internal derangement, and c arthritis. Complicated anatomy of the TMJ was the reason for developing standardized radiographic techniques to diagnose TMDs. The introduction of computed tomography (CT in the diagnosis of TMJ disorders enabled much better delineation of anatomical structures of the joint due to lack of tissue superposition. Cone beam CT (CBCT is the latest imaging modality for craniofacial deformities, with a lesser radiation exposure and cheaper cost when compared to CT. A systematic literature search was done to identify articles describing degenerative osseous changes of the TMJ using CBCT and conventional CT. Electronic search of scientific papers was carried out in PubMed (MeSH, ScienceDirect, and Cochrane databases using specific keywords. In this systematic review, all the selected articles demonstrate the role of CBCT and CT in diagnosing the degenerative osseous changes of the TMJ. The studies included in the review suggested that CT has been the method of choice to assess the TMJ dynamics and contours of the cortical bone.

  2. Preliminary clinical experience with a dedicated interventional robotic system for CT-guided biopsies of lung lesions: a comparison with the conventional manual technique

    Energy Technology Data Exchange (ETDEWEB)

    Anzidei, Michele; Argiro, Renato; Porfiri, Andrea; Boni, Fabrizio; Zaccagna, Fulvio; Napoli, Alessandro; Leonardi, Andrea; Bezzi, Mario; Catalano, Carlo [University of Rome, Department of Radiological, Oncological and Anatomopathological Sciences - Radiology - Sapienza, Rome (Italy); Anile, Marco; Venuta, Federico [University of Rome, Department of Thoracic Surgery - Sapienza, Rome (Italy); Vitolo, Domenico [University of Rome, Department of Radiological, Oncological and Anatomopathological Sciences - Pathology - Sapienza, Rome (Italy); Saba, Luca [Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari-Polo di Monserrato, Monserrato (Italy); Longo, Flavia [University of Rome, Department of Radiological, Oncological and Anatomopathological Sciences - Oncology - Sapienza, Rome (Italy)

    2015-05-01

    Evaluate the performance of a robotic system for CT-guided lung biopsy in comparison to the conventional manual technique. One hundred patients referred for CT-guided lung biopsy were randomly assigned to group A (robot-assisted procedure) or group B (conventional procedure). Size, distance from entry point and position in lung of target lesions were evaluated to assess homogeneity differences between the two groups. Procedure duration, dose length product (DLP), precision of needle positioning, diagnostic performance of the biopsy and rate of complications were evaluated to assess the clinical performance of the robotic system as compared to the conventional technique. All biopsies were successfully performed. The size (p = 0.41), distance from entry point (p = 0.86) and position in lung (p = 0.32) of target lesions were similar in both groups (p = 0.05). Procedure duration and radiation dose were significantly reduced in group A as compared to group B (p = 0.001). Precision of needle positioning, diagnostic performance of the biopsy and rate of complications were similar in both groups (p = 0.05). Robot-assisted CT-guided lung biopsy can be performed safely and with high diagnostic accuracy, reducing procedure duration and radiation dose in comparison to the conventional manual technique. (orig.)

  3. PET/CT-guided treatment planning for paediatric cancer patients: a simulation study of proton and conventional photon therapy

    DEFF Research Database (Denmark)

    Kornerup, Josefine S.; Brodin, N. P.; Bjork-Eriksson, T.;

    2015-01-01

    OBJECTIVE: To investigate the impact of including fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT). METHODS: Target volumes were first delineated without and subsequently re-delineated with access to (18)F-FDG PET......) and estimated risk of secondary cancer (SC). RESULTS: Considerable deviations between CT- and PET/CT-guided target volumes were seen in 3 out of the 11 patients studied. However, averaging over the whole cohort, CT or PET/CT guidance introduced no significant difference in the shape or size of the target...... volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT. CONCLUSION: Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing...

  4. Feasibility of perfusion CT technique integrated into conventional {sup 18}FDG/PET-CT studies in lung cancer patients: clinical staging and functional information in a single study

    Energy Technology Data Exchange (ETDEWEB)

    Ippolito, Davide; Capraro, Cristina; Sironi, Sandro [University of Milano-Bicocca, School of Medicine, Milan (Italy); University of Milano-Bicocca, Department of Diagnostic Radiology, H.S. Gerardo Monza, Via Pergolesi 11, Monza, Milan (Italy); Guerra, Luca [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine and PET Unit - Molecular Bioimaging Centre, Monza (Italy); De Ponti, Elena [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Medical Physics, Monza (Italy); Messa, Cristina [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine and PET Unit - Molecular Bioimaging Centre, Monza (Italy); Tecnomed Foundation, University of Milano-Bicocca, Institute for Bioimaging and Molecular Physiology, National Research Council, Milan (Italy)

    2013-02-15

    To assess the additional functional vascular information and the relationship between perfusion measurements and glucose metabolism (SUVmax) obtained by including a perfusion CT study in a whole-body contrast-enhanced PET/CT protocol in primary lung cancer lesions. Enrolled in this prospective study were 34 consecutive patients with a biopsy-proven diagnosis of lung cancer who were referred for contrast-enhanced PET/CT staging. This prospective study was approved by our institutional review board, and informed consent was obtained from all patients. Perfusion CT was performed with the following parameters: 80 kV, 200 mAs, 30 scans during intravenous injection of 50 ml contrast agent, flow rate 5 ml/s. Another bolus of contrast medium (3.5 ml/s, 80 ml, 60-s delay) was administered to ensure a full diagnostic contrast-enhanced CT scan for clinical staging. The perfusion CT data were used to calculate a range of tumour vascularity parameters (blood flow, blood volume and mean transit time), and tumour FDG uptake (SUVmax) was used as a metabolic indicator. Quantitative and functional parameters were compared and in relation to location, histology and tumour size. The nonparametric Kruskal-Wallis rank sum test was used for statistical analysis. A cut-off value of 3 cm was used according to the TNM classification to discriminate between T1 and T2 tumours (i.e. T1b vs. T2a). There were significant perfusion differences (lower blood volumes and higher mean transit time) between tumours with diameter >30 mm and tumours with diameter <30 mm (p < 0.05; blood volume 5.6 vs. 7.1 ml/100 g, mean transit time 8.6 vs. 3.9 s, respectively). Also there was a trend for blood flow to be lower in larger lesions (p < 0.053; blood flow 153.1 vs. 98.3 ml/100 g tissue/min). Significant inverse correlations (linear regression) were found between blood volume and SUVmax in tumours with diameter >30 mm in diameter. Perfusion CT combined with PET/CT is feasible technique that may provide

  5. DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomised, controlled study

    Energy Technology Data Exchange (ETDEWEB)

    Geisel, Dominik; Zimmermann, Elke; Rief, Matthias; Greupner, Johannes; Hamm, Bernd [Charite Medical School, Department of Radiology, Berlin (Germany); Laule, Michael; Knebel, Fabian [Charite Medical School, Department of Cardiology, Berlin (Germany); Dewey, Marc [Charite Medical School, Department of Radiology, Berlin (Germany); Charite, Institut fuer Radiologie, Berlin (Germany)

    2012-08-15

    To prospectively compare induced DNA double-strand breaks by cardiac computed tomography (CT) and conventional coronary angiography (CCA). 56 patients with suspected coronary artery disease were randomised to undergo either CCA or cardiac CT. DNA double-strand breaks were assessed in fluorescence microscopy of blood lymphocytes as indicators of the biological effects of radiation exposure. Radiation doses were estimated using dose-length product (DLP) and dose-area product (DAP) with conversion factors for CT and CCA, respectively. On average there were 0.12 {+-} 0.06 induced double-strand breaks per lymphocyte for CT and 0.29 {+-} 0.18 for diagnostic CCA (P < 0.001). This relative biological effect of ionising radiation from CCA was 1.9 times higher (P < 0.001) than the effective dose estimated by conversion factors would have suggested. The correlation between the biological effects and the estimated radiation doses was excellent for CT (r = 0.951, P < 0.001) and moderate to good for CCA (r = 0.862, P < 0.001). One day after radiation, a complete repair of double-strand breaks to background levels was found in both groups. Conversion factors may underestimate the relative biological effects of ionising radiation from CCA. DNA double-strand break assessment may provide a strategy for individualised assessments of radiation. (orig.)

  6. Comparative Study on 16-slice CT Coronary Angiography vs Conventional Coronary Angiography-A Report of 38 Cases

    Institute of Scientific and Technical Information of China (English)

    Yan CHEN; Ping HAN; Bo LIANG; Huimin LIANG; Ziqiao LEI; Zhiliang TIAN; Gansheng FENG; Jie XIAO

    2008-01-01

    The clinical application of 16-slice CT coronary angiography (CTCA) and the impact of plaques differently characterized on assessing coronary artery stenosis were evaluated. Thirty-eight patients with coronary artery disease diagnosed by conventional coronary angiography (CAG) un- derwent 16-slice CTCA (collimation: 16×0.75 mm; rotation time: 420 msec; kernel: 35f; effective current: 500 mAs; tube voltage: 120 kV). The interval between CTCA and CAG was within one month. CTCA was evaluated by consensus of two independent experienced radiologists unknowing CAG findings. Original images, maximum intensity projections and multiplanar reconstructions were used to assess coronary artery stenosis. For a determined plaque an attenuation value≥130 HU was considered as calcified, and <130 HU noncalcified. The plaques were then classified into significant calcification (extensive calcification), medium calcification (small isolated calcification) and noncal- cification. The diagnostic accuracy of 16-slice CTCA findings as well as to detect ≥50% stenoses caused by plaques was evaluated respectively regarding CAG as the standard of reference. In com- parison with CAG findings, the sensitivity, specificity, positive and negative predictive value derived from CTCA for mild stenosis (<50%) were 72.7%, 38.5%, 50%, 62.5%, respectively; for moderate stenosis (50%-75%) 82.4%, 72.7%, 70%, 84.2%, resepctively; and for severe coronary stenosis (>75%) 85%, 90.5%, 81%, 92.7% respectively. With the increase of stenoses degree, the value of CTCA was greater. For the classification of the plaque calcification with ≥50% stenosis CTCA at- tained the sensitivity, specificity, positive and negative predictive value for severe calcificatoin 73.3%, 22.2%, 61.1% and 33.3%, respectively; for moderate calcification 70%, 55.6%, 63.6% and 62.5%, respectively; for noncalcification 93.8%, 85.7%, 93.8% and 85.7% respectively. CTCA was restricted in assessing coronary artery stenosis in the

  7. PET/CT-guided treatment planning for paediatric cancer patients: a simulation study of proton and conventional photon therapy

    Science.gov (United States)

    Brodin, N P; Björk-Eriksson, T; Birk Christensen, C; Kiil-Berthelsen, A; Aznar, M C; Hollensen, C; Markova, E; Munck af Rosenschöld, P

    2015-01-01

    Objective: To investigate the impact of including fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT). Methods: Target volumes were first delineated without and subsequently re-delineated with access to 18F-FDG PET scan information, on duplicate CT sets. RT plans were generated for three-dimensional conformal photon RT (3DCRT) and intensity-modulated proton therapy (IMPT). The results were evaluated by comparison of target volumes, target dose coverage parameters, normal tissue complication probability (NTCP) and estimated risk of secondary cancer (SC). Results: Considerable deviations between CT- and PET/CT-guided target volumes were seen in 3 out of the 11 patients studied. However, averaging over the whole cohort, CT or PET/CT guidance introduced no significant difference in the shape or size of the target volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT. Conclusion: Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing or decreasing irradiated volumes, suggesting that the long-term morbidity of RT in childhood would on average remain largely unaffected. Advances in knowledge: 18F-FDG PET-based RT planning does not systematically change NTCP or SC risk for paediatric cancer patients compared with CT only. 3 out of 11 patients had a distinct change of target volumes when PET-guided planning was introduced. Dice and mismatch metrics are not sufficient to assess the consequences of target volume differences in the context of RT. PMID:25494657

  8. Difference in the Set-up Margin between 2D Conventional and 3D CT Based Planning in Patients with Early Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Sun Mi; Chun, Mi Sun; Kim, Mi Hwa; Oh, Young Taek; Noh, O Kyu [Ajou University School of Medicine, Seoul (Korea, Republic of); Kang, Seung Hee [Inje University, Ilsan Paik Hospital, Ilsan (Korea, Republic of)

    2010-11-15

    Simulation using computed tomography (CT) is now widely available for radiation treatment planning for breast cancer. It is an important tool to help define the tumor target and normal tissue based on anatomical features of an individual patient. In Korea, most patients have small sized breasts and the purpose of this study was to review the margin of treatment field between conventional two-dimensional (2D) planning and CT based three-dimensional (3D) planning in patients with small breasts. Twenty-five consecutive patients with early breast cancer undergoing breast conservation therapy were selected. All patients underwent 3D CT based planning with a conventional breast tangential field design. In 2D planning, the treatment field margins were determined by palpation of the breast parenchyma (In general, the superior: base of the clavicle, medial: midline, lateral: mid - axillary line, and inferior margin: 2 m below the inflamammary fold). In 3D planning, the clinical target volume (CTV) ought to comprise all glandular breast tissue, and the PTV was obtained by adding a 3D margin of 1 cm around the CTV except in the skin direction. The difference in the treatment field margin and equivalent field size between 2D and 3D planning were evaluated. The association between radiation field margins and factors such as body mass index, menopause status, and bra size was determined. Lung volume and heart volume were examined on the basis of the prescribed breast radiation dose and 3D dose distribution. The margins of the treatment field were smaller in the 3D planning except for two patients. The superior margin was especially variable (average, 2.5 cm; range, -2.5 to 4.5 cm; SD, 1.85). The margin of these targets did not vary equally across BMI class, menopause status, or bra size. The average irradiated lung volume was significantly lower for 3D planning. The average irradiated heart volume did not decrease significantly. The use of 3D CT based planning reduced the

  9. 外伤性迟发性颅内血肿常规CT研究%Study on delayed traumatic intracranial hematoma using conventional CT

    Institute of Scientific and Technical Information of China (English)

    高志友

    2011-01-01

    目的 探讨常规CT如何尽早而准确地测出外伤性迟发性颅内血肿.方法 搜集常规CT复查证实的外伤性迟发性颅内血肿39例,对其首次常规CT检查及复查的CT图像特点进行分析.结果 39例迟发性颅内血肿首次常规CT检查主要异常表现包括:①局限性蛛网膜下腔出血30例.②局限性脑密度减低,灰白质分界不清15例.③局部轻度占位效应18例.④颅骨骨折5例.结论 外伤性迟发性颅内血肿的发生率与伤后首次常规CT检查表现密切相关,应在24h以内复查,以6~12h最佳.%Objective To determine how early and reliably delayed traumatic intracranial hematoma can be detected on conventional CT scanning. Methods The manifestations of the initial conventional CT studies and follow up CT examinations of 39 delayed traumatic intracranial hematoma were analyzed. Results The abnormal findings of conventional CT studies of the 39 delayed traumatic intracranial hematoma included:①Local subarachnoid space hemorrhage in 30 cases:②Decreased density of the local brain parenchyma and disappeared difference between gray and white matter of the same area in 15 cases: ③Slight space occupying effect in 18 cases:④skull bone fracture in 5 cases. Conclusion The morbidity of delayed traumatic intracranial hematoma is closely related to the manifestation of the first cranial conventional CT after injury, The time of observation should be within 24 hours of injury, and within 6 - 12 hours was the beat.

  10. Perfusion CT allows prediction of therapy response in non-small cell lung cancer treated with conventional and anti-angiogenic chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Tacelli, Nunzia; Santangelo, Teresa; Remy, Jacques [University of Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); University of Lille Nord de France, Faculty of Medicine, Henri Warembourg, Lille (France); Scherpereel, Arnaud; Cortot, Alexis; Wallyn, Frederic [University of Lille Nord de France, Faculty of Medicine, Henri Warembourg, Lille (France); University of Lille Nord de France, Department of Pulmonary and Thoracic Oncology, Lille (France); Duhamel, Alain; Deken, Valerie [University of Lille Nord de France, Faculty of Medicine, Henri Warembourg, Lille (France); University of Lille Nord de France, Department of Medical Statistics, Lille (France); Klotz, Ernst [Siemens Healthcare, Computed Tomography Division, Forchheim (Germany); Lafitte, Jean-Jacques [University of Lille Nord de France, Faculty of Medicine, Henri Warembourg, Lille (France); University of Lille Nord de France, Department of Pulmonary and Thoracic Oncology, Lille (France); Pasteur Institute of Lille, INSERM unit 1019, CIIL, Lille (France); Remy-Jardin, Martine [University of Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); University of Lille Nord de France, Faculty of Medicine, Henri Warembourg, Lille (France); Hospital Calmette, Department of Thoracic Imaging, Lille cedex (France)

    2013-08-15

    To determine whether CT can depict early perfusion changes in lung cancer treated by anti-angiogenic drugs, allowing prediction of response. Patients with non-small cell lung cancer, treated by conventional chemotherapy with (Group 1; n = 17) or without (Group 2; n = 23) anti-vascular endothelial growth factor (anti-VEGF) drug (bevacizumab) underwent CT perfusion before (TIME 0) and after 1 (TIME 1), 3 (TIME 2) and 6 (TIME 3) cycles of chemotherapy. The CT parameters evaluated included: (1) total tumour vascular volume (TVV) and total tumour extravascular flow (TEF); (2) RECIST (Response Evaluation Criteria in Solid Tumours) measurements. Tumour response was also assessed on the basis of the clinicians' overall evaluation. In Group 1, significant reduction in perfusion was identified between baseline and: (1) TIME 1 (TVV, P = 0.0395; TEF, P = 0.015); (2) TIME 2 (TVV, P = 0.0043; TEF, P < 0.0001); (3) TIME 3 (TVV, P = 0.0034; TEF, P = 0.0005) without any significant change in Group 2. In Group 1: (1) the reduction in TVV at TIME 1 was significantly higher in responders versus non-responders at TIME 2 according to RECIST (P = 0.0128) and overall clinicians' evaluation (P = 0.0079); (2) all responders at TIME 2 had a concurrent decrease in TVV and TEF at TIME 1. Perfusion CT demonstrates early changes in lung cancer vascularity under anti-angiogenic chemotherapy that may help predict therapeutic response. (orig.)

  11. Nodular lesions seen on CTAP not on conventional CT in known hepatocellular carcinoma (HCC) patients: positive predictive value for HCC or precusor of HCC

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jae Chun; Lee, Yong Woo; Hwang, Mi Soo [College of Medicine, Yeungnam University, Daegu (Korea, Republic of)

    1995-01-15

    To evaluate intrahepatic nodular lesions detected on CTAP but not on conventional contrast CT in regard to its relationship with satellite nodules or borderline malignancies. From June 1991 to March 1994, CTAP was undertaken in 132 cases with confirmed hepatocellular carcinoma (HCC), or which 35 cases having 82 lesions were suitable for analysis (excluding the cases which had no follow-up studies, showed segmental abnormal portal perfusion, no additional lesions and, or inumerable lesions). The CTAP findings were compared with those on artery dominant imaging studies (angiography, DSA, bolus dynamic CT, arterial CT, Lipiodol CT) taken during the same period (to confirm the presence of lesions) and the findings on follow-up imaging studies (to assess the development of malignancy). Arterial vascularity was identified in 35 of 82 lesions (42.7%) on arterial dominant imaging studies. Development into malignancy was identified on follow-up imaging studies in 25 of remained 47 lesions (53.2%). The total positive predictive value of nodules on CTAP was 73.2% (35 + 25/82), but the predictive value for HCC by follow-up only was 53.2%. Given the difficulties in detecting intranodular arterial flow and the short follow-up duration in many patients, the actual positive value might be higher.

  12. Dual-energy direct bone removal CT angiography for evaluation of intracranial aneurysm or stenosis: comparison with conventional digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshiyuki [National Cardiovascular Center, Department of Radiology, Osaka (Japan); St. Luke' s International Hospital, Department of Radiology, Tokyo (Japan); Uotani, Kensuke; Nakazawa, Tetsuro; Higashi, Masahiro; Yamada, Naoaki; Hori, Yoshiro; Kanzaki, Suzu; Fukuda, Tetsuya; Naito, Hiroaki [National Cardiovascular Center, Department of Radiology, Osaka (Japan); Itoh, Toshihide [Siemens Asahi Medical Technologies, Tokyo (Japan)

    2009-04-15

    Dual-energy CT can be applied for bone elimination in cerebral CT angiography (CTA). The aim of this study was to compare the results of dual-energy direct bone removal CTA (DE-BR-CTA) with those of digital subtraction angiography (DSA). Twelve patients with intracranial aneurysms and/or ICA stenosis underwent a dual-source CT in dual-energy mode. Post-processing software selectively removed bone structures using the two energy data sets. Three-dimensional images with and without bone removal were reviewed and compared to DSA. Dual-energy bone removal was successful in all patients. For 10 patients, bone removal was good and CTA maximum-intensity projection (MIP) images could be used for vessel evaluation. For two patients, bone removal was moderate with some bone remnants, but this did not inhibit the three-dimensional visualization. Three aneurysms adjacent to the skull base were only partially visible in conventional CTA but were fully visible in DE-BR-CTA. In five patients with ICA stenosis, DE-BR-CTA revealed the stenotic lesions on the MIP images. The correlation between DSA and DE-BR-CTA was good (R {sup 2}=0.822), but DE-BR-CTA led to an overestimation of stenosis. DE-BR-CTA was able to eliminate bone structure using only a single CT data acquisition and is useful to evaluate intracranial aneurysms and stenosis. (orig.)

  13. Fluorine-18 fluorocholine PET-CT localizes hyperparathyroidism in patients with inconclusive conventional imaging : a multicenter study from the Netherlands

    NARCIS (Netherlands)

    Kluijfhout, Wouter P; Vorselaars, Wessel M C M; van den Berk, Sandra A M; Vriens, Menno R; Borel Rinkes, Inne H M; Valk, Gerlof D; van Dalen, Thijs; de Klerk, John M H; de Keizer, Bart

    2016-01-01

    BACKGROUND: Several reports have shown good performance of fluorine-18 fluorocholine (F-FCH) PET-computed tomography (CT) for parathyroid localization, although overall evidence remains scarce. We collected data from three institutions in the Netherlands and investigated the performance of F-FCH PET

  14. Enhancement patterns of pancreatic adenocarcinoma on conventional dynamic multi-detector row CT: Correlation with angiogenesis and fibrosis

    Institute of Scientific and Technical Information of China (English)

    Yuki Hattori; Toshifumi Gabata; Osamu Matsui; Kentaro Mochizuki; Hirohisa Kitagawa; Masato Kayahara; Tetsuo Ohta; Yasuni Nakanuma

    2009-01-01

    AIM: To evaluate retrospectively the correlation between enhancement patterns on dynamic computed tomography (CT) and angiogenesis and fibrosis in pancreatic adenocarcinoma.METHODS: Twenty-three patients with pancreatic adenocarcinoma underwent dynamic CT and tumor resection. In addition to the absolute and relative enhanced value that was calculated by subtracting the attenuation value on pre-contrast from those on contrast-enhanced CT in each phase, we defined one parameter, "tumor-aorta enhancement ratio", which was calculated by dividing enhancement of pancreatic cancer by enhancement of abdominal aorta in each phase. These enhancement patterns were correlated with the level of vascular endothelial growth factor (VEGF), microvessel density (MVD), and extent of fibrosis.RESULTS: The absolute enhanced value in the arterial phase correlated with the level of VEGF and MVD (P = 0.047, P = 0.001). The relative enhanced value in arterial phase and tumor-aorta enhancement ratio (arterial) correlated with MVD (P = 0.003, P = 0.022). Tumor-aorta enhancement ratio (arterial) correlated negatively with the extent of fibrosis (P = 0.004). The tumors with greater MVD and higher expression of VEGF tended to show high enhancement in the arterial dominant phase. On the other hand, the tumors with a larger amount of fibrosis showed a negative correlation with the grade of enhancement during the arterial phase.CONCLUSION: Enhancement patterns on dynamic CT correlated with angiogenesis and may be modified by the extent of fibrosis.

  15. SU-E-I-39: Combining Conventional Tomographic Imaging Strategy and Interior Tomography for Low Dose Dual-Energy CT (DECT)

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Q [School of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Xing, L [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Xiong, G; Elmore, K; Min, J [Dalio Institute of Cardiovascular Imaging, New York- Presbyterian Hospital and Weill Cornell Medical College, New York, NY (United States)

    2015-06-15

    Purpose: Dual-energy CT (DECT) affords quantitative information of tissue density and provides a new dimension for disease diagnosis and treatment planning. The technique, however, increases the imaging dose because of the doubled scans, and thus hinders its widespread clinical applications. The purpose of this work is to develop a novel hybrid DECT image acquisition and reconstruction strategy, in which one of the energies is dealt by interior tomography while the other one is obtained using conventional tomography approach. Methods: In the proposed hybrid imaging strategy, the projection data of one of the energies (e.g., high-energy) were acquired and processed in an interior scanning model, whereas the other energy in the conventional tomographic approach. It known that, if the ROI is piecewise constant or polynomial, the interior ROI can be reconstructed with TV or HOT minimization. Here we extend the TV based interior reconstruction method into dual-energy situation. The ROI images so obtained were overlaid in the context of conventional CT of the companion energy. A material based composition in ROI was used in the proposed reconstruction framework. Results: In the simulation experiment with a diagnostic DECT geometry and energies, we were able to derive the densities of soft-tissues and bones in the ROI with high fidelity. In the experimental CBCT study, both kV and MV data were collected using the on-board kV and MV imaging system. The MV data were truncated only across the ROI. Using the interior tomography reconstruction above, we were able to obtain the ROI images as that obtained using un-truncated MV data with known tissue densities. Conclusion: The proposed DECT imaging strategy provides an effective way to extract tissue density information in the ROI and in the context of anatomical images of CT imaging, with much reduced imaging dose.

  16. Characterization of Small Focal Renal Lesions: Diagnostic Accuracy with Single-Phase Contrast-enhanced Dual-Energy CT with Material Attenuation Analysis Compared with Conventional Attenuation Measurements.

    Science.gov (United States)

    Marin, Daniele; Davis, Drew; Roy Choudhury, Kingshuk; Patel, Bhavik; Gupta, Rajan T; Mileto, Achille; Nelson, Rendon C

    2017-09-01

    Purpose To determine whether single-phase contrast material-enhanced dual-energy material attenuation analysis improves the characterization of small (1-4 cm) renal lesions compared with conventional attenuation measurements by using histopathologic analysis and follow-up imaging as the clinical reference standards. Materials and Methods In this retrospective, HIPAA-compliant, institutional review board-approved study, 136 consecutive patients (95 men and 41 women; mean age, 54 years) with 144 renal lesions (111 benign, 33 malignant) measuring 1-4 cm underwent single-energy unenhanced and contrast-enhanced dual-energy computed tomography (CT) of the abdomen. For each renal lesion, attenuation measurements were obtained; attenuation change of greater than or equal to 15 HU was considered evidence of enhancement. Dual-energy attenuation measurements were also obtained by using iodine-water, water-iodine, calcium-water, and water-calcium material basis pairs. Mean lesion attenuation values and material densities were compared between benign and malignant renal lesions by using the two-sample t test. Diagnostic accuracy of attenuation measurements and dual-energy material densities was assessed and validated by using 10-fold cross-validation to limit the effect of optimistic bias. Results By using cross-validated optimal thresholds at 100% sensitivity, iodine-water material attenuation images significantly improved specificity for differentiating between benign and malignant renal lesions compared with conventional enhancement measurements (93% [103 of 111]; 95% confidence interval: 86%, 97%; vs 81% [90 of 111]; 95% confidence interval: 73%, 88%) (P = .02). Sensitivity with iodine-water and calcium-water material attenuation images was also higher than that with conventional enhancement measurements, although the difference was not statistically significant. Conclusion Contrast-enhanced dual-energy CT with material attenuation analysis improves specificity for

  17. Flat-detector computed tomography with intravenous contrast material application in experimental aneurysms: comparison with multislice CT and conventional angiography.

    Science.gov (United States)

    Struffert, Tobias; Doelken, Marc; Adamek, Edyta; Schwarz, Marc; Engelhorn, Tobias; Kloska, Stephan; Ott, Sabine; Doerfler, Arnd

    2010-05-01

    Despite limited soft tissue resolution flat-detector computed tomography (FD-CT) provides substantial superior spatial resolution in comparison with multislice computed tomography (MS-CT). This may add value in the visualization of small vascular structures if intravenous contrast application leads to substantial opacification and visibility of intracranial vessels or aneurysms. To evaluate the feasibility of visualization of vascular structures by FD-CT angiography (FD-CTA) after intravenous contrast injection compared with MS-CTA and intra-arterial digital subtracted angiography (IADSA) in an animal model. Aneurysms were created in the right common carotid artery in six New Zealand White Rabbits using the elastase technique. Imaging was performed using FD-CTA, MS-CTA (injection of 1 ml/kg body weight) and IADSA. Anonymized volume rendering reconstruction (VRT), maximum intensity projection (MIP), and multiplanar reconstruction (MPR) images were reconstructed and evaluated by two experienced reviewers for aneurysm geometry and vascular structure anatomy using standard tools of a dedicated workstation. Aneurysms could be successfully created in all animals. Measurements of aneurysm geometry (aneurysm height, width, neck width) and vascular structures (brachiocephalic trunk, carotid artery diameter and plane) were nearly identical in all three modalities. Intra- and inter-observer correlations of the different parameters showed high r values between 0.83 and 0.99. Our results show the feasibility of FD-CTA in comparison with MS-CTA and IADSA in an animal model. Despite limited soft tissue resolution, opacification of vascular structures with sufficient contrast to the surrounding structures was possible in all animals. Vascular structures appeared better delineated in FD-CTA than in MS-CTA, probably due to the superior spatial resolution.

  18. Patient-Specific CT-Based Instrumentation versus Conventional Instrumentation in Total Knee Arthroplasty: A Prospective Randomized Controlled Study on Clinical Outcomes and In-Hospital Data

    Directory of Open Access Journals (Sweden)

    Andrzej Kotela

    2015-01-01

    Full Text Available Total knee arthroplasty (TKA is a frequently performed procedure in orthopaedic surgery. Recently, patient-specific instrumentation was introduced to facilitate correct positioning of implants. The aim of this study was to compare the early clinical results of TKA performed with patient-specific CT-based instrumentation and conventional technique. A prospective, randomized controlled trial on 112 patients was performed between January 2011 and December 2011. A group of 112 patients who met the inclusion and exclusion criteria were enrolled in this study and randomly assigned to an experimental or control group. The experimental group comprised 52 patients who received the Signature CT-based implant positioning system, and the control group consisted of 60 patients with conventional instrumentation. Clinical outcomes were evaluated with the KSS scale, WOMAC scale, and VAS scales to assess knee pain severity and patient satisfaction with the surgery. Specified in-hospital data were recorded. Patients were followed up for 12 months. At one year after surgery, there were no statistically significant differences between groups with respect to clinical outcomes and in-hospital data, including operative time, blood loss, hospital length of stay, intraoperative observations, and postoperative complications. Further high-quality investigations of various patient-specific systems and longer follow-up may be helpful in assessing their utility for TKA.

  19. Assessment of 70-keV virtual monoenergetic spectral images in abdominal CT imaging: A comparison study to conventional polychromatic 120-kVp images.

    Science.gov (United States)

    Rassouli, Negin; Chalian, Hamid; Rajiah, Prabhakar; Dhanantwari, Amar; Landeras, Luis

    2017-04-18

    To evaluate the image quality of 70-keV virtual monoenergetic (monoE) abdominal CT images compared to 120-kVp polychromatic images generated from a spectral detector CT (SDCT) scanner. This prospective study included generation of a 120-kVp polychromatic dataset and a 70-keV virtual monoE dataset after a single contrast-enhanced CT acquisition on a SDCT scanner (Philips Healthcare) during portal venous phase. The attenuation values (HU), noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured in the liver, spleen, pancreas, kidney, aorta, portal vein, and muscle. The subjective image quality including noise, soft tissue contrast, sharpness, and overall image quality were graded on a 5-point Likert scale by two radiologists independently (1-worst image quality, 5-best image quality). Statistical analysis was performed using paired sample t test and Fleiss's Kappa. Fifty-five patients (54.3 ± 16.8 y/o; 28 M, 27 F) were recruited. The noise of target organs was significantly lower in virtual monoE images in comparison to polychromatic images (p virtual monoE images (p virtual monoE images was significantly better (p virtual monoE images, respectively. The inter-reader agreement for overall image quality was good (Kappa were 0.767 and 0.762 for polychromatic and virtual monoE images, respectively). In abdominal imaging, 70-keV virtual monoE CT images demonstrated significantly better noise, SNR, CNR, and subjective score compared to conventional 120-kVp polychromatic images.

  20. Diagnostic performance of CT colonography with limited cathartic preparation in colorectal cancer screening; comparison with conventional colonoscopy

    Directory of Open Access Journals (Sweden)

    Mohammed Farghally Amin

    2015-09-01

    Conclusion: This study proved that CTC with limited cathartic bowel preparation and iodinated agents for fecal tagging can obtain high sensitivity and PPV values results for <5 mm polyps comparable to those obtained with conventional preparation with laxatives. Furthermore, this method could really improve the acceptance of CTC for colorectal cancer screening.

  1. Effectiveness and efficiency of CT-colonography compared to conventional colonoscopy for the early detection and diagnosis of colorectal cancer

    Directory of Open Access Journals (Sweden)

    Hiebinger, Cora

    2009-02-01

    Full Text Available Health political background: Colorectal cancer (CC is the second most common cancer and cause of cancer death for both men and women in Germany. Various methods for early detection of CC exist, including conventional coloscopy which is reimbursed within the scope of cancer screening, as well as computertomography-coloscopy (CTC which is currently not reimbursed. Scientific background: CTC is a mere diagnostic procedure which has a lower risk of perforation than conventional coloscopy. However, as it is an x-ray procedure, it exposes the patient to radiation. Conventional coloscopy is considered the gold standard due to its high sensitivity and specificity for locating adenomas. Furthermore, it offers the advantage that in addition to extended diagnostic measures therapeutic measures can be undertaken during the procedure. Research questions: This HTA-report aims to evaluate the effectiveness and efficiency of CTC in comparison to conventional coloscopy in the early detection and diagnosis of colorectal cancer and/or its precursors and which ethical and legal aspects have to be considered. Methods: The systematic literature search (27 international literature data bases yielded a total of 1,713 abstracts. After a two-step selection process 36 publications remained to be assessed. Results: The results regarding the effectivity of CTC in diagnosis and screening for colorectal cancer and/or its precursors are partly promising, however, they are very heterogeneous. Therefore, regarding its sensitivity and specificity, CTC cannot be considered an equivalent alternative to conventional coloscopy for diagnosis and screening. The heterogeneity of results is due to technical (device type, settings, patient dependent (preparation and operator dependent (training factors. No economic results for a comparison of the procedures for diagnosis exist. Regarding the cost-effectiveness of a CTC-screening, international model calculations are available. According

  2. MO-E-17A-06: Organ Dose in Abdomen-Pelvis CT: Does TG 111 Equilibrium Dose Concept Better Accounts for KVp Dependence Than Conventional CTDI?

    Energy Technology Data Exchange (ETDEWEB)

    Li, X [Cleveland State University, Cleveland, OH (United States); Morgan, A; Davros, W [Cleveland State University, Cleveland, OH (United States); Cleveland Clinic, Cleveland, Ohio (United States); Dong, F [Cleveland Clinic, Cleveland, Ohio (United States); Primak, A [Siemens Medical Solutions USA, Inc. (United States); Segars, W [Duke University, Durham, NC (United States)

    2014-06-15

    Purpose: In CT imaging, a desirable quality assurance (QA) dose quantity should account for the dose variability across scan parameters and scanner models. Recently, AAPM TG 111 proposed to use equilibrium dose-pitch product, in place of CT dose index (CTDI100), for scan modes involving table translation. The purpose of this work is to investigate whether this new concept better accounts for the kVp dependence of organ dose than the conventional CTDI concept. Methods: The adult reference female extended cardiac-torso (XCAT) phantom was used for this study. A Monte Carlo program developed and validated for a 128-slice CT system (Definition Flash, Siemens Healthcare) was used to simulate organ dose for abdomenpelvis scans at five tube voltages (70, 80, 100, 120, 140 kVp) with a pitch of 0.8 and a detector configuration of 2x64x0.6 mm. The same Monte Carlo program was used to simulate CTDI100 and equilibrium dose-pitch product. For both metrics, the central and peripheral values were used together with helical pitch to calculate a volume-weighted average, i.e., CTDIvol and (Deq)vol, respectively. Results: While other scan parameters were kept constant, organ dose depended strongly on kVp; the coefficient of variation (COV) across the five kVp values ranged between 70–75% for liver, spleen, stomach, pancreas, kidneys, colon, small intestine, bladder, and ovaries, all of which were inside the primary radiation beam. One-way analysis of variance (ANOVA) for the effect of kVp was highly significant (p=3e−30). When organ dose was normalized by CTDIvol, the COV across the five kVp values reduced to 7–16%. The effect of kVp was still highly significant (p=4e−4). When organ dose was normalized by (Deq)vol, the COV further reduced to 4−12%. The effect of kVp was borderline significant (p=0.04). Conclusion: In abdomen-pelvis CT, TG 111 equilibrium dose concept better accounts for kVp dependence than the conventional CTDI. This work is supported by a faculty startup

  3. The effect of equipment set up on patient radiation dose in conventional and CT angiography of the renal arteries.

    Science.gov (United States)

    Kemerink, G J; De Haan, M W; Vasbinder, G B C; Frantzen, M J; Schultz, F W; Zoetelief, J; Jansen, J Th M; Van Engelshoven, J M A

    2003-09-01

    Patient radiation dose in angiography of the renal arteries was assessed and optimized after installing new radiological equipment. In three separate studies (n=50, 25 and 20) patient exposure was monitored in detail. For the first study default factory settings were used, for the second the number of digital subtraction angiography (DSA) images was halved and the X-ray beam filtering during fluoroscopy was increased, and for the third study filtering during DSA was increased as well. Standard projections were derived and used in Monte Carlo simulations to derive dose conversion coefficients to calculate effective dose from the dose-area product (DAP). Dose conversion coefficients were also calculated for CT angiography (CTA). Using default factory settings on the new angiography system, DAP, number of images and effective dose were much higher than on the replaced unit. For the studies given above, DAP was reduced from 144 Gy cm(2) to 65 Gy cm(2) to 32 Gy cm(2), and effective dose from 22 mSv to 11 mSv to 9.1 mSv, respectively. Effective dose due to CTA was 5.2 mSv. It is concluded that modern angiography systems, resulting in high customer satisfaction, may readily cause much higher patient exposure than older systems. These doses may also be much higher than necessary. Optimization before putting such systems into use is absolutely essential. Internationally accepted recommendations for image quality and technique factors in angiography would be of great help.

  4. Progressing features of atypical mycobacterial infection in the lung on conventional and high resolution CT (HRCT) images

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Daizo; Niwatsukino, Hiroshi; Nakajo, Masayuki [Kagoshima Univ. (Japan). Faculty of Medicine; Oyama, Takao

    2001-10-01

    The aim of this study was to clarify the localization of abnormalities within secondary pulmonary lobules and the changes in follow-up studies of pulmonary atypical mycobacterial infection (AMI) by conventional and high-resolution computed tomography (HRCT). Forty-six patients (16 men and 30 women; 43-84 years) with pulmonary AMI (M. intracellulare 36; M. avium 10) in the lung were examined by conventional and HRCT. In peripheral zones, all patients had the nodule located in the terminal or lobular bronchiole, and most of the patients also had nodules accompanied with a wedge-shaped or linear shadow connected with the pleura. In the follow-up scans, new centrilobular nodules appeared in other segments, and consolidation or ground-glass pattern appeared newly and was preceded by nodules. Bronchiectasis became more severe in five of 38 follow-up patients. The common HRCT findings of AMI were centrilobular, peribronchovascular nodules, bronchiectasis, consolidation, and pleural thickening/adhesion. The nodules frequently connected with the pleura. The initial and follow-up studies suggest that the disease may begin in the terminal bronchiole or as preexisting bronchiectasis and spread transbronchially along the draining bronchus or towards the pleura to produce lesions such as new nodules, cavities, consolidation, pleuritis, and bronchiectasis, or more severe bronchiectasis. (author)

  5. 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.)

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  8. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  9. A comparison of conventional maximum intensity projection with a new depth-specific topographic mapping technique in the CT analysis of proximal tibial subchondral bone density

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, James D. [University of Saskatchewan, Department of Mechanical Engineering, Saskatoon, SK (Canada); University of British Columbia, Department of Mechanical Engineering, Vancouver, BC (Canada); Kontulainen, Saija A. [University of Saskatchewan, College of Kinesiology, Saskatoon, SK (Canada); Masri, Bassam A.; Wilson, David R. [University of British Columbia, Department of Orthopaedics, Vancouver, BC (Canada)

    2010-09-15

    The objective was to identify subchondral bone density differences between normal and osteoarthritic (OA) proximal tibiae using computed tomography osteoabsorptiometry (CT-OAM) and computed tomography topographic mapping of subchondral density (CT-TOMASD). Sixteen intact cadaver knees from ten donors (8 male:2 female; mean age:77.8, SD:7.4 years) were categorized as normal (n = 10) or OA (n = 6) based upon CT reconstructions. CT-OAM assessed maximum subchondral bone mineral density (BMD). CT-TOMASD assessed average subchondral BMD across three layers (0-2.5, 2.5-5 and 5-10 mm) measured in relation to depth from the subchondral surface. Regional analyses of CT-OAM and CT-TOMASD included: medial BMD, lateral BMD, and average BMD of a 10-mm diameter area that searched each medial and lateral plateau for the highest ''focal'' density present within each knee. Compared with normal knees, both CT-OAM and CT-TOMASD demonstrated an average of 17% greater whole medial compartment density in OA knees (p < 0.016). CT-OAM did not distinguish focal density differences between OA and normal knees (p > 0.05). CT-TOMASD focal region analyses revealed an average of 24% greater density in the 0- to 2.5-mm layer (p = 0.003) and 36% greater density in the 2.5- to 5-mm layer (p = 0.034) in OA knees. Both CT-OAM and TOMASD identified higher medial compartment density in OA tibiae compared with normal tibiae. In addition, CT-TOMASD indicated greater focal density differences between normal and OA knees with increased depth from the subchondral surface. Depth-specific density analyses may help identify and quantify small changes in subchondral BMD associated with OA disease onset and progression. (orig.)

  10. Application of contrast-enhanced ultrasound in the diagnosis of solid pancreatic lesions—A comparison of conventional ultrasound and contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Zhihui, E-mail: fanzhihui_1026@163.com [Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Ultrasound, Peking University Cancer Hospital and Institute, No. 52, Fucheng Road, Haidian District, Beijing 100142 (China); Li, Ying, E-mail: 18901033676@126.com [Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Radiology, Peking University Cancer Hospital and Institute, No. 52, Fucheng Road, Haidian District, Beijing 100142 (China); Yan, Kun, E-mail: ydbz@sina.com [Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Ultrasound, Peking University Cancer Hospital and Institute, No. 52, Fucheng Road, Haidian District, Beijing 100142 (China); Wu, Wei, E-mail: wuwei@163.com [Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Ultrasound, Peking University Cancer Hospital and Institute, No. 52, Fucheng Road, Haidian District, Beijing 100142 (China); Yin, Shanshan, E-mail: yshshmd@yahoo.com [Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Ultrasound, Peking University Cancer Hospital and Institute, No. 52, Fucheng Road, Haidian District, Beijing 100142 (China); Yang, Wei, E-mail: weiwei02032001@gmail.com [Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Ultrasound, Peking University Cancer Hospital and Institute, No. 52, Fucheng Road, Haidian District, Beijing 100142 (China); Xing, Baocai, E-mail: xinbaocai88@sina.com [Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Hepatic Biliary and Pancreatic Surgery, Peking University Cancer Hospital and Institute, No. 52, Fucheng Road, Haidian District, Beijing 100142 (China); and others

    2013-09-15

    Objective: To explore the diagnostic value of contrast-enhanced ultrasound (CEUS) by comparison with conventional ultrasound (US) and contrast-enhanced CT (CECT) in solid pancreatic lesions. Method: Ninety patients with solid pancreatic focal lesions were enrolled, including 36 cases of pancreatic carcinoma, 28 cases of pancreatitis, 6 cases of pancreatic neuroendocrine tumor, 12 cases of solid pseudopapillary tumor of the pancreas, 6 cases of pancreatic metastases, 1 case of cavernous hemolymphangioma and 1 case of lymphoma. US and CEUS were applied respectively for the diagnosis of a total of 90 cases of solid pancreatic lesions. The diagnostic results were scored on a 5-point scale. Results of CEUS were compared with CECT. Results: (1) 3-score cases (undetermined) diagnosed by CEUS were obviously fewer than that of US, while the number of 1-score (definitely benign) and 5-score (definitely malignant) cases diagnosed by CEUS was significantly more than that of US. There was a significant difference in the distribution of final scores using the two methods (p < 0.001). The overall diagnostic accuracies of the 90 cases for CEUS and US were 83.33% and 44.44%, respectively, which indicated an obvious advantage for CEUS (p < 0.001). (2) The diagnostic consistency among three ultrasound doctors: the kappa values calculated for US were 0.537, 0.444 and 0.525, compared with 0.748, 0.645 and 0.795 for CEUS. The interobserver agreement for CEUS was higher than that for US. (3) The sensitivity, specificity and accuracy of the diagnosis of pancreatic carcinoma with CEUS and CECT were 91.7% and 97.2%, 87.0% and 88.9%, and 88.9% and 92.2%, respectively, while for the diagnosis of pancreatitis, the corresponding indices were 82.1% and 67.9%, 91.9% and 100%, and 88.9% and 90%, respectively, showing no significant differences (p > 0.05). Conclusion: CEUS has obvious superiority over conventional US in the general diagnostic accuracy of solid pancreatic lesions and in the

  11. Does low-field dedicated extremity MRI (E-MRI) reliably detect bone erosions in rheumatoid arthritis? A comparison of two different E-MRI units and conventional radiography with high-resolution CT scanning

    DEFF Research Database (Denmark)

    Duer-Jensen, A; Ejbjerg, B; Albrecht-Beste, E

    2008-01-01

    OBJECTIVES: To compare the ability of two different E-MRI units and conventional radiography (CR) to identify bone erosions in rheumatoid arthritis (RA) metacarpophalangeal (MCP) and wrist joints with CT scanning as the standard reference method. METHODS: 20 patients with RA and 5 controls...... underwent CR, CT and two E-MRI examinations (Esaote Biomedica Artoscan and MagneVu MV1000) of one hand during a 2-week period. In all modalities, each bone of the wrist and MCP joints was blindly evaluated for erosions. MagneVu images were also assessed for the proportion of each bone being visualised...... were visualised entirely and 37.9% of bones were 67-99% visualised. In MCP joints, 84.2% of bones were visualised entirely and 15.8% of bones were 67-99% visualised. CONCLUSION: With CT as the reference method for detecting erosions in RA hands, the Artoscan showed higher sensitivity than the Magne...

  12. Combined SPECT/CT improves detection of initial bone invasion and determination of resection margins in squamous cell carcinoma of the head and neck compared to conventional imaging modalities

    Energy Technology Data Exchange (ETDEWEB)

    Kolk, A. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Oral and Maxillofacial Surgery, Munich (Germany); Klinikum rechts der Isar, Technische Universitaet Muenchen, Klinik und Poliklinik fuer Mund-Kiefer und Gesichtschirurgie, Muenchen (Germany); Schuster, T. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Institute of Medical Statistics and Epidemiology, Munich (Germany); Chlebowski, A.; Kesting, M.; Bissinger, O.; Weitz, J. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Oral and Maxillofacial Surgery, Munich (Germany); Lange, P. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Diagnostic Radiology, Munich (Germany); Scheidhauer, K.; Schwaiger, M.; Dinges, J. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Nuclear Medicine, Munich (Germany)

    2014-07-15

    Knowledge of the presence and extent of bone infiltration is crucial for planning the resection of potential bone-infiltrating squamous cell carcinomas of the head and neck (HNSCC). Routinely, plain-film radiography, multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) are used for preoperative staging, but they show relatively high rates of false-positive and false-negative findings. Scintigraphy with {sup 99m}Tc-bisphosphonate has the ability to show increased metabolic bone activity. If combined with anatomical imaging (e.g. (SPECT)/CT), it facilitates the precise localization of malignant bone lesions. The aim of this study was to analyse the indications and advantages of SPECT/CT compared with standard imaging modalities and histology with regard to specificity and sensitivity A longitudinally evaluated group of 30 patients with biopsy-proven HNSCC adjacent to the mandible underwent {sup 99m}Tc-bisphosphonate SPECT/CT, MRI, MSCT and conventional radiography before partial or rim resection of the mandible was performed. Bone infiltration was first evaluated with plain films, MSCT and MRI. In a second reading, SPECT/CT data were taken into account. The results (region and certainty of bone invasion) were evaluated among the different imaging modalities and finally compared with histological specimens from surgical resection as the standard of reference. For a better evaluation of the hybrid property of SPECT/CT, a retrospectively evaluated group of 20 additional patients with tumour locations similar to those of the longitudinally examined SPECT/CT group underwent SPECT, MSCT and MRI. To assess the influence of dental foci on the specificity of the imaging modalities, all patients were separated into two subgroups depending on the presence or absence of teeth in the area of potential tumour-bone contact. Histologically proven bone infiltration was found in 17 patients (57 %) when analysed by conventional imaging modalities. SPECT/CT data

  13. Posttherapeutic {sup 131}I SPECT-CT offers high diagnostic accuracy when the findings on conventional planar imaging are inconclusive and allows a tailored patient treatment regimen

    Energy Technology Data Exchange (ETDEWEB)

    Kohlfuerst, S.; Igerc, I.; Gallowitsch, H.J.; Gomez-Segovia, I.; Matschnig, S.; Mayr, J.; Mikosch, P.; Lind, P. [State Hospital Klagenfurt, Department of Nuclear Medicine and Endocrinology, PET-CT Centre, Klagenfurt (Austria); Lobnig, M. [State Hospital Klagenfurt, Department of Radiology, Klagenfurt (Austria); Beheshti, M. [St. Vincent' s Hospital, Department of Nuclear Medicine and Endocrinology, Linz (Austria)

    2009-06-15

    The purpose of this prospective study was to determine the diagnostic impact and influence on patient treatment of posttherapeutic {sup 131}I SPECT-CT when the findings on planar posttherapeutic whole-body scintigraphy (ptWBS) were inconclusive. A total of 53 SPECT-CT scans were performed in 41 patients with thyroid cancer after high-dose {sup 131}I therapy (2.944 to 7.526 GBq {sup 131}I) because of diagnostic uncertainty on ptWBS. Physiological uptake in the salivary glands, gastric mucosa, gut, nasal mucosa, urinary tract and liver were considered to be normal. Any other foci of increased {sup 131}I uptake, except iodine uptake clearly located in the thyroid bed, were considered to be abnormal. The data were evaluated on a lesion and a patient basis. Regarding neck lesions, SPECT-CT provided a diagnostic impact in 26/90 lesions (28.9%) and confirmed the diagnosis in 64/90 lesions (71.1%). On a patient basis, SPECT-CT changed N status in 12/33 patients (36.4%), provided a diagnostic impact in 21/33 patients (63.6%) and led to a treatment change in 8/33 patients (24.2%). Regarding lesions distant from the neck, SPECT-CT confirmed the diagnosis in 62/71 lesions (87.3%) and had a diagnostic impact in 9/71 lesions (12.7%). On a patient basis, SPECT-CT changed M status in 4/19 patients (21.1%), had a diagnostic impact in 14/19 patients (73.7%) and led to a treatment change in 2/19 patients (10.5%). Considering all patients, SPECT-CT led to a treatment change in 10/41 patients (24.4%). Integrated SPECT-CT is a useful tool, especially in cases of diagnostic uncertainty and helps to individualize patient management. (orig.)

  14. The role of whole body spiral CT in the primary work-up of polytrauma patients - comparison with conventional radiography and abdominal sonography; Die Rolle der Ganzkoerper-Spiral-CT bei der Primaerdiagnostik polytraumatisierter Patienten - Vergleich mit konventioneller Radiographie und Abdomensonographie

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, T.; Schlippenbach, J. von; Wolf, K.J. [Klinik und Poliklinik fuer Radiologie und Nuklearmedizin, Charite - Campus Benjamin Franklin (Germany); Stahel, P.F.; Ertel, W. [Klinik fuer Unfall- und Wiederherstellungschirurgie, Charite - Campus Benjamin Franklin (Germany)

    2004-08-01

    Purpose: To evaluate the role of routine 'whole body spiral CT' in the primary work-up of polytrauma patients for injuries of the thorax, abdomen and spine, and to compare the results with those of conventional radiography of the chest and spine and abdominal ultrasound. Materials and Methods: Fifty consecutive polytrauma patients underwent contrast-enhanced single slice spiral CT (5 mm collimation) from the vertex to the floor of the pelvis as part of the primary work-up after emergency room admission. Overlapping high resolution sections and sagittal reformations of the spine were obtained. Reports of additional chest radiographs (n=43), abdominal ultrasound examinations (n=47) and spine radiographs (n=36) performed in the emergency room were available for retrospective comparison. The 'final diagnoses', which served as the standard of reference, were taken from the patients' records using all information that became available until discharge or death, such as findings from further imaging, surgery and autopsy. Results: CT showed 109 (97%) of 112 thoracic and abdominal soft-tissue injuries. Relevant injuries missed were an early splenic laceration and an early pelvic hematoma, both of which became clinically apparent several hours later. There were 4 false positive CT findings. Conventional chest radiography demonstrated only 20% of thoracic and sonography 22% of abdominal injuries. Chest radiography and sonography produced 2 false-positive findings each. CT showed 66 (87%) of 76 vertebral fractures including all 19 unstable ones. CT missed 5 anterior vertebral body and 5 spinous/transverse process fractures. Conventional radiography found 71% of vertebral fractures including only 50% of the unstable one. (orig.)

  15. Diagnostic accuracy of cone-beam CT in the assessment of mandibular invasion of lower gingival carcinoma: Comparison with conventional panoramic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Momin, Mohammad A. [Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8549 (Japan)], E-mail: momin.orad@tmd.ac.jp; Okochi, Kiyoshi [Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8549 (Japan)], E-mail: kiyoshi.orad@tmd.ac.jp; Watanabe, Hiroshi [Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8549 (Japan)], E-mail: hiro.orad@tmd.ac.jp; Imaizumi, Akiko [Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8549 (Japan)], E-mail: ima.orad@tmd.ac.jp; Omura, Ken [Oral Surgery, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8549 (Japan)], E-mail: omura.osur@tmd.ac.jp; Amagasa, Teruo [Maxillofacial Surgery, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8549 (Japan)], E-mail: t-amagasa.mfs@tmd.ac.jp; Okada, Norihiko [Diagnostic Oral Pathology, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8549 (Japan)], E-mail: nokd.opth@tmd.ac.jp; Ohbayashi, Naoto [Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8549 (Japan)], E-mail: nao.orad@tmd.ac.jp; Kurabayashi, Tohru [Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8549 (Japan)], E-mail: kura.orad@tmd.ac.jp

    2009-10-15

    Purpose: To evaluate the diagnostic accuracy of cone-beam CT in assessing mandibular invasion by lower gingival carcinoma and compare it with that of panoramic radiography. Patients and methods: Fifty patients with squamous cell carcinoma of the lower gingiva who were examined by both panoramic radiography and cone-beam CT before surgery were included in this study. Five radiologists used a 6-point rating scale to independently evaluate cone-beam CT and panoramic images for the presence or absence of alveolar bone and mandibular canal involvement by tumor. Using the histopathogical findings as the gold standard, we calculated and compared the area under the receiver operating characteristic curve (Az value) and the sensitivity and specificity of the two imaging modalities. Results: In evaluations of both alveolar bone and mandibular canal involvement, the mean Az value for cone-beam CT (0.918 and 0.977, respectively) was significantly higher than that for panoramic radiography (0.793 and 0.872, respectively). The mean sensitivity for cone-beam CT (89% and 99%, respectively) was significantly higher than that for panoramic radiography (73% and 56%, respectively). There was no significant difference in the mean specificity. While cone-beam CT could provide high-resolution three-dimensional images, the image quality around the alveolar crest was often hampered by severe dental artifacts and image noise, resulting in difficulties in detecting subtle alveolar invasion. Conclusion: Cone-beam CT was significantly superior to panoramic radiography in evaluating mandibular invasion by lower gingival carcinoma. Its diagnostic value in detecting subtle alveolar invasion, however, may be limited by severe dental artifacts and image noise.

  16. Comparison of the utility of whole-body MRI with and without contrast-enhanced Quick 3D and double RF fat suppression techniques, conventional whole-body MRI, PET/CT and conventional examination for assessment of recurrence in NSCLC patients

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine (Japan); Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Nishio, Mizuho [Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine (Japan); Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Koyama, Hisanobu [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Yoshikawa, Takeshi; Matsumoto, Sumiaki [Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine (Japan); Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Takenaka, Daisuke [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Radiology, Hyogo Cancer Center, Akashi (Japan); Seki, Shinichiro [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Tsubakimoto, Maho [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa (Japan); Sugimura, Kazuro [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan)

    2013-11-01

    Purpose: The purpose of this study was to compare diagnostic capabilities for assessment of recurrence in non-small cell lung cancer (NSCLC) patients by contrast-enhanced whole-body MRI (CE-WB-MRI) with and without CE-Quick 3D and double RF fat suppression technique (DFS), FDG-PET/CT and conventional radiological examinations. Materials and methods: A total of 134 pathologically proven and completely resected NSCLC patients (78 males, 56 females; mean age: 72 years) underwent FDG-PET/CT, CE-WB-MRI with and without Quick 3D and DFS at 3 T as well as conventional radiological examinations. The probability of recurrence was assessed with a 5-point scoring system on a per-patient basis, and final diagnosis was made by consensus between two readers. The capability for overall recurrence assessment by all the methods was compared by means of ROC analysis and their sensitivity, specificity and accuracy by means of McNemar's test. Results: Although areas under the curve did not show any significant differences, specificity (100%) and accuracy (95.5%) of CE-WB-MRI with CE-Quick 3D and DFS were significantly higher than those of FDG-PET/CT (specificity: 93.6%, p = 0.02; accuracy: 89.6%, p = 0.01) and conventional radiological examinations (specificity: 92.7%, p = 0.01; accuracy: 91.0%, p = 0.03). In addition, specificity of CE-WB-MRI without CE-Quick 3D and DFS (100%) was significantly higher than that of FDG-PET/CT (p = 0.02) and conventional radiological examinations (p = 0.01). Conclusion: Specificity and accuracy of CE-WB-MRI with CE-Quick 3D and DFS for assessment of recurrence in NSCLC patients are at least as high as, or higher than those of others.

  17. Assessment of image quality and low-contrast detectability in abdominal CT of obese patients: comparison of a novel integrated circuit with a conventional discrete circuit detector at different tube voltages

    Energy Technology Data Exchange (ETDEWEB)

    Euler, A.; Heye, T.; Kekelidze, M.; Bongartz, G.; Schindera, Sebastian T. [University of Basel Hospital, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Szucs-Farkas, Z. [Hospital Centre of Biel, Institute of Radiology, Biel (Switzerland); Sommer, C. [University Hospital, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Schmidt, B. [Siemens Healthcare Sector, Forchheim (Germany)

    2014-10-15

    To compare image quality and low-contrast detectability of an integrated circuit (IC) detector in abdominal CT of obese patients with conventional detector technology at low tube voltages. A liver phantom with 45 lesions was placed in a water container to mimic an obese patient and examined on two different CT systems at 80, 100 and 120 kVp. The systems were equipped with either the IC or conventional detector. Image noise was measured, and the contrast-to-noise-ratio (CNR) was calculated. Low-contrast detectability was assessed independently by three radiologists. Radiation dose was estimated by the volume CT dose index (CTDI{sub vol}). The image noise was significantly lower, and the CNR was significantly higher with the IC detector at 80, 100 and 120 kVp, respectively (P = 0.023). The IC detector resulted in an increased lesion detection rate at 80 kVp (38.1 % vs. 17.2 %) and 100 kVp (57.0 % vs. 41.0 %). There was no difference in the detection rate between the IC detector at 100 kVp and the conventional detector at 120 kVp (57.0 % vs. 62.2 %). The CTDI{sub vol} at 80, 100 and 120 kVp measured 4.5-5.2, 7.3-7.9 and 9.8-10.2 mGy, respectively. The IC detector at 100 kVp resulted in similar low-contrast detectability compared to the conventional detector with a 120-kVp protocol at a radiation dose reduction of 37 %. (orig.)

  18. [Imaging techniques in the preoperative diagnosis of soft tissue tumors. A comparison of MRT, CT, sonography, angiography and conventional x-rays].

    Science.gov (United States)

    Roeren, T; Gindele, A; Grosspietsch, C; Dueck, M; Kauffmann, G W

    1992-12-01

    In a study on 51 patients with histologically confirmed soft tissue tumors (STT), we retrospectively evaluated the preoperative use of imaging procedures (MRI, CT, ultrasound, angiography, plain film) for identification of tumor size, delineation, and determination of malignancy and tissue type. The findings were correlated with intraoperative findings and histological diagnosis. The overall diagnostic method of choice for preoperative imaging of STT is MRI, followed by CT. Ultrasound, although sensitive, lacks the required specificity. Angiography and plain film can only be used for specific indications, as they generally do not make it possible to stage the tumor. Combining our results with those from the more recent literature, we propose a diagnostic algorithm according to which MRI would generally be performed for preoperative staging of STT. CT and plain film should only be used if bony infiltration is suspected; angiography is indicated for planning intraarterial chemotherapy or embolization or if vascular infiltration is probable.

  19. Prospective comparison of 18F-FDG PET with conventional imaging modalities (CT, MRI, US) in lymph node staging of head and neck cancer.

    Science.gov (United States)

    Adams, S; Baum, R P; Stuckensen, T; Bitter, K; Hör, G

    1998-09-01

    The aims of this study were to investigate the detection of cervical lymph node metastases of head and neck cancer by positron emission tomographic (PET) imaging with fluorine-18 fluorodeoxyglucose (FDG) and to perform a prospective comparison with computed tomography (CT), magnetic resonance imaging (MRI), sonographic and histopathological findings. Sixty patients with histologically proven squamous cell carcinoma were studied by PET imaging before surgery. Preoperative endoscopy (including biopsy), CT, MRI and sonography of the cervical region were performed in all patients within 2 weeks preceding 18F-FDG whole-body PET. FDG PET images were analysed visually and quantitatively for objective assessment of regional tracer uptake. Histopathology of the resected neck specimens revealed a total of 1284 lymph nodes, 117 of which showed metastatic involvement. Based on histopathological findings, FDG PET correctly identified lymph node metastases with a sensitivity of 90% and a specificity of 94% (Pcontrolled study confirms FDG PET as the procedure with the highest sensitivity and specificity for detecting lymph node metastases of head and neck cancer and has become a routine method in our University Medical Center. Furthermore, the optimal diagnostic modality may be a fusion image showing the increased metabolism of the tumour and the anatomical localization.

  20. Parosteal lipoma - a case report: conventional radiology, CT and MRI; Lipoma parosteal - relato de um caso: radiologia convencional, tomografia computadorizada e ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Silvio Cavalcanti [Pernambuco Univ., Recife, PE (Brazil). Hospital das Clinicas]|[Instituto Materno Infantil de Pernambuco, Recife, PE (Brazil); Nascimento, Edilene Cristina do; Silva, Ivone Martins da [Pernambuco Univ., Recife PE (Brazil). Hospital das Clinicas. Servico de Radiologia

    1996-03-01

    The authors report a case parosteal lipoma, a rare benign tumor, associated with exostosis, in proximal radius. The diagnosis aspects in conventional radiology, computed tomography and magnetic resonance imaging are presented, as well as a review of the medical literature about the case. (author). 7 refs., 3 figs.

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... liver, shows up in shades of gray, and air appears black. With CT scanning, numerous x-ray ... ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x- ...

  2. Sensitivity of Image Features to Noise in Conventional and Respiratory-Gated PET/CT Images of Lung Cancer: Uncorrelated Noise Effects.

    Science.gov (United States)

    Oliver, Jasmine A; Budzevich, Mikalai; Hunt, Dylan; Moros, Eduardo G; Latifi, Kujtim; Dilling, Thomas J; Feygelman, Vladimir; Zhang, Geoffrey

    2016-08-08

    The effect of noise on image features has yet to be studied in depth. Our objective was to explore how significantly image features are affected by the addition of uncorrelated noise to an image. The signal-to-noise ratio and noise power spectrum were calculated for a positron emission tomography/computed tomography scanner using a Ge-68 phantom. The conventional and respiratory-gated positron emission tomography/computed tomography images of 31 patients with lung cancer were retrospectively examined. Multiple sets of noise images were created for each original image by adding Gaussian noise of varying standard deviation equal to 2.5%, 4.0%, and 6.0% of the maximum intensity for positron emission tomography images and 10, 20, 50, 80, and 120 Hounsfield units for computed tomography images. Image features were extracted from all images, and percentage differences between the original image and the noise image feature values were calculated. These features were then categorized according to the noise sensitivity. The contour-dependent shape descriptors averaged below 4% difference in positron emission tomography and below 13% difference in computed tomography between noise and original images. Gray level size zone matrix features were the most sensitive to uncorrelated noise exhibiting average differences >200% for conventional and respiratory-gated images in computed tomography and 90% in positron emission tomography. Image feature differences increased as the noise level increased for shape, intensity, and gray-level co-occurrence matrix features in positron emission tomography and for gray-level co-occurrence matrix and gray-level size zone matrix features in conventional computed tomography. Investigators should be aware of the noise effects on image features.

  3. Flat-detector computed tomography in the assessment of intracranial stents: comparison with multi detector CT and conventional angiography in a new animal model.

    Science.gov (United States)

    Struffert, Tobias; Ott, Sabine; Adamek, Edyta; Schwarz, Marc; Engelhorn, Tobias; Kloska, Stephan; Deuerling-Zheng, Yu; Doerfler, Arnd

    2011-08-01

    Careful follow up is necessary after intracranial stenting because in-stent restenosis (ISR) or residual stenosis (RS) is not rare. A minimally invasive follow-up imaging technique is desirable. The objective was to compare the visualisation of stents in Flat Detector-CT Angiography (FD-CTA) after intravenous contrast medium injection (i.v.) with Multi Detector Computed Tomography Angiography (MD-CTA) and Digital Subtracted Angiography (DSA) in an animal model. Stents were implanted in the carotid artery of 12 rabbits. In 6 a residual stenosis (RS) was surgically created. Imaging was performed using FD-CTA, MD-CTA and DSA. Measurements of the inner and outer diameter and cross-section area of the stents were performed. Stenosis grade was calculated. In subjective evaluation FD-CTA was superior to MD-CTA. FD-CTA was more accurate compared with DSA than MD-CTA. Cross-sectional area of the stent lumen was significantly larger (p < 0.05) in FD-CTA in comparison to MD-CTA. Accurate evaluation of stenosis was impossible in MD-CTA. There was no statistically significant difference in the stenosis grade of DSA and FD-CTA. Our results show that visualisation of stent and stenosis using intravenous FD-CTA compares favourably with DSA and may replace DSA in the follow-up of patients treated with intracranial stents.

  4. Synthetic Hounsfield units from spectral CT data

    Science.gov (United States)

    Bornefalk, Hans

    2012-04-01

    Beam-hardening-free synthetic images with absolute CT numbers that radiologists are used to can be constructed from spectral CT data by forming ‘dichromatic’ images after basis decomposition. The CT numbers are accurate for all tissues and the method does not require additional reconstruction. This method prevents radiologists from having to relearn new rules-of-thumb regarding absolute CT numbers for various organs and conditions as conventional CT is replaced by spectral CT. Displaying the synthetic Hounsfield unit images side-by-side with images reconstructed for optimal detectability for a certain task can ease the transition from conventional to spectral CT.

  5. Depiction of Nidi and Fibrovascular Zones of Osteoid Ostemas Using Gamma Correction Tc 99m HDP Pinhole Bone Scan and Conventional Radiograph, and Correlation with CT, MRI, and PVC Phantom Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Youg Whee [Sung Ae Hospital, Seoul (Korea, Republic of); Kim, Sung Hoon; Chung, Yong An; Bahk, Won Jong; Park, Jung Mee; Kang, You Mee; Choi, Woo Hee; Park, Young Ha; Sohn, Hyung Sun; Kim, Byung Ki; Chung, Soo Kyo [The Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2011-03-15

    For the precise imaging diagnosis of osteoid osteoma (OO), the identification of the nidus and fibrovascular zone (FVZ) is essential. However, the latter sign has received little attention because it is difficult to demonstrate. We applied the recently introduced gamma correction (GC) to depict the FVZ on pinhole bone scan (PBS), conventional radiography (CR), and computed tomography (CT). Non gamma correction MRI was also analyzed for reference. Ten patients with histologically proven diagnoses of OO were enrolled in this retrospective study. PBS, CR, and CT were processed by GC to demonstrate the nidi and FVZ as distinct yet integrating components of OO. PBS was performed using a 4mm pinhole collimator 3 h after iv injection of 925 to 1, 110 MBq (25 to 30mCi) of Tc 99m HDP, and anteroposterior and mediolateral CR and transverse CT were taken according to the standard technique. MRI sequences included T1 and T2 weighted images. For gamma correction, we utilized the Photo Correction Wizard program of ACD Photo Editor v3. 1. A team of three qualified nuclear physician radiologists, two nuclear physicians, and one MRI specialist read bone scans, radiographs, and MRIs of OO according to each specialty, and orthopaedic aspects and histology were reviewed by one qualified orthopedic surgeon and two qualified pathologists, respectively. Each observer first read the images separately with basic information about the aim of the study given and then in concert. Interpretive disagreement was settled by discussion and consensus. On pinhole scan, nidi were presented as areas of intense tracer uptake in all cases, and, importantly after GC, a thin ring like zone with lower tracer uptake became visible in seven out of ten cases. GCCR also revealed a thin lucent zone that circumscribed the nidi in six out of ten cases and GCCT in two of four cases. MRI, without GC, presented nidi with high signal in the center and a thin ring like zone with low signal in the periphery in five out

  6. Thoracic CT

    Science.gov (United States)

    ... lungs; CT scan - chest Images CT scan Thyroid cancer - CT scan Pulmonary nodule, solitary - CT scan Lung mass, right upper ... Chest Injuries and Disorders CT Scans Emphysema Lung Cancer Lung Diseases Pleural Disorders Pneumonia Pulmonary Embolism Tuberculosis Browse the Encyclopedia A.D.A. ...

  7. CT- and MR colonography

    DEFF Research Database (Denmark)

    Achiam, Michael Patrick; Bülow, Steffen; Rosenberg, J

    2002-01-01

    . Lately, CT- and MR colonography have emerged as non-invasive methods for colon imaging. METHODS: At present, CTC and MRC require bowel preparation. However, preliminary studies have been carried out without colon preparation. After the colon has been filled with air or contrast, the patient is scanned...... colonography. Future developments with the use of "intelligent" computers, better resolution and faster examinations will make CT and/or MR colonography realistic options to replace conventional diagnostic colonoscopy....

  8. CT paging arteriography with a multidetector-row CT. Advantages in splanchnic arterial imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Seiji [Keio Univ., Tokyo (Japan). School of Medicine

    1999-11-01

    The purpose of this study is to assess the utility of CT paging arteriography with a multidetector-row CT as a replacement for conventional angiography in the evaluation of splanchnic arterial anomalies. Sixty-three patients underwent CT paging arteriography with a multidetector-row CT. In the 56 patients with conventional angiographic correlation, there was only one minor disagreement with CT paging arteriography. In the 7 patients who underwent IVDSA (intra venous digital subtraction angiography), CT paging arteriography defined four hepatic arterial anomalies which could not be depicted by IVDSA. In conclusion, CT paging arteriography provides noninvasive means to identify splanchnic arterial anomalies. (author)

  9. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... tissues show up in shades of gray and air appears black. With CT scanning, numerous x-ray ... ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x- ...

  10. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... A person who is very large may not fit into the opening of a conventional CT scanner ... radiologist will decide which type of examination is best for your child. top of page Additional Information ...

  11. Children's (Pediatric) CT (Computed Tomography)

    Science.gov (United States)

    ... not fit into the opening of a conventional CT scanner or may be over the weight limit—usually 450 pounds—for the moving table. Other imaging methods such as ultrasound or magnetic resonance (MR) imaging ... obtained by CT scanning. Working together, your primary care physician or ...

  12. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  13. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  14. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  16. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  17. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  18. CT- and MR colonography

    DEFF Research Database (Denmark)

    Achiam, Michael Patrick; Bülow, Steffen; Rosenberg, J

    2002-01-01

    . Lately, CT- and MR colonography have emerged as non-invasive methods for colon imaging. METHODS: At present, CTC and MRC require bowel preparation. However, preliminary studies have been carried out without colon preparation. After the colon has been filled with air or contrast, the patient is scanned....... CONCLUSIONS: With the exponential development in computer processing power, CT- and MR colonography holds the promise for future colon examination with the advantages of non-invasiveness, no need for sedation, and probably no bowel preparation. A major disadvantage, however, is the radiation dose during CT...... colonography. Future developments with the use of "intelligent" computers, better resolution and faster examinations will make CT and/or MR colonography realistic options to replace conventional diagnostic colonoscopy....

  19. CTU结合常规CT对2cm以下肾盂移行细胞癌诊断中价值%Diagnostic value of CTU combined with conventional CT shift in transitional cell carcinoma of renal pelvis in below 2 cm

    Institute of Scientific and Technical Information of China (English)

    吴枕戈; 刘绪明; 郑文龙; 郑汉朋; 邱乾德

    2014-01-01

    目的:探讨CTU结合常规CT在2.0cm以下肾盂移行细胞癌诊断中价值。方法回顾性分析经手术病理证实的2.0cm以下肾盂移行细胞癌31例常规CT和CTU表现,研究两种方法对本瘤检出率。结果肿瘤位于肾盂15例,肾盏9例,肾盂与输尿管交接部7例。肿瘤呈结节状充填肾盂或肾盏28例,沿肾盂表面浸润生长3例。肿瘤最大直径1.1~2.0cm ,其中1.5cm以下8例,1.6~2.0cm20例,仅见肾盂壁界限性结节状增厚3例。敏感度常规CT为80.6%,CTU为90.3%;准确度常规CT为54.8%,CTU为77.4%。结论本组研究显示CTU结合常规CT能提高诊断准确率。%Objective To study on CTU combined with conventional CT diagnostic value in transitional cell carcinoma of renal pelvis in below 2 .0 cm .Methods We retrospective analysed of below 2 .0 cm proved by operation and pathology fol-lowing renal pelvic transitional cell carcinoma in 31 cases of conventional CTU and CT manifestations ,studied of two methods in detection of the tumor .Results The tumors located in the renal pelvis in 15 cases ,renal pelvis in 9 cases ,re-nal pelvis and ureter in 7 cases .The tumor was nodular filling kidney or renal calices in 28 cases ,renal pelvis surface infil-tration growth in 3 cases .Maximum tumor diameter ranged from 1 .1 to 2 .0 cm ,in which below 1 .5 cm was 8 cases ,1.6~2 .0 cm 20 cases ,3 cases were nodular thickening of the pelvic wall boundaries .The sensitivity of the conventional CT was 80 .6% ,CTU 90 .3% .The accuracy of conventional CT was 54 .8% ,CTU 77 .4% .Conclusion The results showed that CTU combined with conventional CT significantly improved the accuracy of diagnosis .

  20. CT diagnosis of gall stone ileus

    Energy Technology Data Exchange (ETDEWEB)

    Leen, G.L.S.; Finlay, M. (Royal Victoria Infirmary, Newcastle upon Tyne (UK). Dept. of Radiology Newcastle General Hospital, Newcastle upon Tyne (UK). Dept. of Radiology)

    1990-09-01

    We report a case of gall stone ileus in which only small bowel obstruction was seen on the conventional abdominal film and the diagnosis was made by computed tomography (CT). With the availability of CT and its increasing use in the investigation of the acute abdomen, CT examination will occasionally be performed on gall stone ileus patients. Awareness of the CT findings in gall stone ileus will result in early diagnosis leading to a reduction in the mortality rate. (orig.).

  1. Head CT scan

    Science.gov (United States)

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... hold your breath for short periods. A complete scan usually take only 30 seconds to a few ...

  2. Does low-field dedicated extremity MRI (E-MRI) reliably detect RA bone erosions? A comparison of two different E-MRI units and conventional radiography with high resolution CT

    DEFF Research Database (Denmark)

    Duer, Anne; Ejbjerg, Bo; Albrecht-Beste, Elisabeth;

    2008-01-01

    underwent, within 2 weeks, CR, CT and two E-MRI (Esaote Biomedica; Artoscan and MagneVu; MV1000) examination of one hand. In all modalities each bone of wrist and (MCP) joints was blindedly evaluated for erosions. Furthermore, MagneVu images were assessed for the proportion of each bone being visualized...

  3. CT of thymoma

    Energy Technology Data Exchange (ETDEWEB)

    Sone, S.; Higashihara, T.; Morimoto, S.; Ikezoe, J.; Arisawa, J. (Osaka Univ. (Japan). Faculty of Medicine)

    1982-08-01

    Based on 17 patients with thymoma (8 with myasthenia gravis and 9 free from it); 1. The effectiveness of CT, conventional radiography and pneumomediastinography in the detection of thymomas was determined and the results compared. 2. The CT findings of thymomas were discussed and the CT features which seemed to suggest malignant thymomas were evaluated. The results were as follows: 1. Of the 17 cass with thymomas, 13 were diagnosed from p-a films, 13 from lateral films, and 16 from CT. Of the 16 thymomas, 14 were diagnosed from lateral tomography. Mass densities were shown in all 15 cases in which pneumomediastinography were performed. 2. Benign thymomas showed round or oval smoothly marginated mass. The fatty plane between the mass and the mediastinal structures was nicely preserved. 3. Malignant thymoma frequently showed a plaque-like mass with more or less irregular or lobulated contours with obliteration of the fatty planes of the cardiovascular structures. Tumor calcification was shown in 4 of 10 malignant thymomas. 4. Slight tumor invasion to the mediastinal pleura and lung was difficult to predict from the CT images.

  4. Seventh-generation CT

    Science.gov (United States)

    Besson, G. M.

    2016-03-01

    A new dual-drum CT system architecture has been recently introduced with the potential to achieve significantly higher temporal resolution than is currently possible in medical imaging CT. The concept relies only on known technologies; in particular rotation speeds several times higher than what is possible today could be achieved leveraging typical x-ray tube designs and capabilities. However, the architecture lends itself to the development of a new arrangement of x-ray sources in a toroidal vacuum envelope containing a rotating cathode ring and a (optionally rotating) shared anode ring to potentially obtain increased individual beam power as well as increase total exposure per rotation. The new x-ray source sub-system design builds on previously described concepts and could make the provision of multiple conventional high-power cathodes in a CT system practical by distributing the anode target between the cathodes. In particular, relying on known magnetic-levitation technologies, it is in principle possible to more than double the relative speed of the electron-beam with respect to the target, thus potentially leading to significant individual beam power increases as compared to today's state-of-the-art. In one embodiment, the proposed design can be naturally leveraged by the dual-drum CT concept previously described to alleviate the problem of arranging a number of conventional rotating anode-stem x-ray tubes and power conditioners on the limited space of a CT gantry. In another embodiment, a system with three cathodes is suggested leveraging the architecture previously proposed by Franke.

  5. CT metrizamide myelography in intrathoracic meningocele

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ki Man; Woo, Seong Ku; Kim, Ok Bae; Suh, Soo Jhi [Keimyung University Medical College, Daegu (Korea, Republic of)

    1985-06-15

    Intrathoracic meningocele is a protrusion of the spinal meninges through an intervertebral foramen into the thoracic cavity. The majority occur in association with neurofibromatosis. The authors experienced a case of intrathoracic meningocele in 26 years old male patient associated with neurofibromatosis, and present conventional CT and CT metrizamide myelographic findings.

  6. CT colonography: an update

    Energy Technology Data Exchange (ETDEWEB)

    Aschoff, Andrik J.; Ernst, Andrea S.; Brambs, Hans-Juergen; Juchems, Markus S. [University Hospitals of Ulm, Diagnostic and Interventional Radiology, Ulm (Germany)

    2008-03-15

    Computed tomographic (CT) colonography (CTC) - also known as ''virtual colonoscopy'' - was first described more than a decade ago. As advancements in scanner technology and three-dimensional (3D) postprocessing helped develop this method to mature into a potential option in screening for colorectal cancer, the fundamentals of the examination remained the same. It is a minimally invasive, CT-based procedure that simulates conventional colonoscopy using 2D and 3D computerized reconstructions. The primary aim of CTC is the detection of colorectal polyps and carcinomas. However, studies reveal a wide performance variety in regard to polyp detection, especially for smaller polyps. This article reviews the available literature, discusses established indications as well as open issues and highlights potential future developments of CTC. (orig.)

  7. CT portography by multidetector helical CT. Comparison of three rendering models

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Yoshiharu; Imuta, Masanori; Funama, Yoshinori; Kadota, Masataka; Utsunomiya, Daisuke; Shiraishi, Shinya; Hayashida, Yoshiko; Yamashita, Yasuyuki [Kumamoto Univ. (Japan). School of Medicine

    2002-12-01

    The purpose of this study was to assess the value of multidetector CT portography in visualizing varices and portosystemic collaterals in comparison with conventional portography, and to compare the visualizations obtained by three rendering models (volume rendering, VR; minimum intensity projection, MIP; and shaded surface display, SSD). A total of 46 patients with portal hypertension were examined by CT and conventional portography for evaluation of portosystemic collaterals. CT portography was performed by multidetector CT (MD-CT) scanner with a slice thickness of 2.5 mm and table feed of 7.5 mm. Three types of CT portographic models were generated and compared with transarterial portography. Among 46 patients, 48 collaterals were identified on CT transverse images, while 38 collaterals were detected on transarterial portography. Forty-four of 48 collaterals identified on CT transverse images were visualized with the MIP model, while 34 and 29 collaterals were visualized by the VR and SSD methods, respectively. The average CT value for the portal vein and varices was 198 HU with data acquisition of 50 sec after contrast material injection. CT portography by multidetector CT provides excellent images in the visualization of portosystemic collaterals. The images of collaterals produced by MD-CT are superior to those of transarterial portography. Among the three rendering techniques, MIP provides the best visualization of portosystemic collaterals. (author)

  8. CT Enterography

    Science.gov (United States)

    ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... kind, unlike MRI. No radiation remains in a patient's body after a CT ... side effects. Risks There is always a slight chance of cancer ...

  9. Computed tomography (CT) of traumatic injuries of the cervical spine

    Energy Technology Data Exchange (ETDEWEB)

    Robotti, G.C.; Geissmann, A.; Steinsiepe, K.

    1986-02-01

    32 patients with traumatic injuries of the cervical spine were investigated by CT. All patients were initially examined by plain films. CT was definitely superior to conventional radiology in compressive fractures of vertebral bodies. In flexion-extension injuries CT was useful showing fractures of the posterior elements in great detail. Conventional tomography was superior to CT in patients with complex dislocations of vertebral bodies. In the absence of fracture CT failed to detect disruptions of ligaments, which were readily shown by functional examination.

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain cavities (ventricles) in ... X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography (CTA) Stroke Brain ...

  11. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  12. Noise characteristics of x-ray differential phase contrast CT

    Science.gov (United States)

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

    2011-03-01

    The noise characteristics of x-ray differential phase contrast computed tomography (DPC-CT) were investigated. Both theoretical derivation and experimental results demonstrated that the dependence of noise variance on spatial resolution in DPC-CT follows an inverse linear law. This behavior distinguishes DPC-CT from conventional absorption based x-ray CT, where the noise variance varies inversely with the cube of the spatial resolution. This anomalous noise behavior in DPC-CT is due to the Hilbert filtering kernel used in the CT reconstruction algorithm, which equally weights all spatial frequency content. Additionally, we demonstrate that the noise power of DPC-CT is scaled by the inverse of spatial frequency and is highly concentrated at the low spatial frequencies, whereas conventional absorption CT increases in power at the high spatial frequencies.

  13. Normal pediatric postmortem CT appearances

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Willemijn M.; Bosboom, Dennis G.H.; Koopmanschap, Desiree H.J.L.M. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Nievelstein, Rutger A.J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Nikkels, Peter G.J. [University Medical Center Utrecht, Department of Pathology, Utrecht (Netherlands); Rijn, Rick R. van [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands)

    2015-04-01

    Postmortem radiology is a rapidly developing specialty that is increasingly used as an adjunct to or substitute for conventional autopsy. The goal is to find patterns of disease and possibly the cause of death. Postmortem CT images bring to light processes of decomposition most radiologists are unfamiliar with. These postmortem changes, such as the formation of gas and edema, should not be mistaken for pathological processes that occur in living persons. In this review we discuss the normal postmortem thoraco-abdominal changes and how these appear on CT images, as well as how to differentiate these findings from those of pathological processes. (orig.)

  14. CT and HR-CT of exogenous allergic alveolitis. Exogen allergische Alveolitis in CT und HR-CT

    Energy Technology Data Exchange (ETDEWEB)

    Lederer, A.; Kullnig, P. (Graz Univ., Univ.-Klinik fuer Radiologie (Austria)); Pongratz, M. (Graz Univ. (Austria). Abt. fuer Lungenkranke)

    1992-09-01

    The CT changes on conventional and high resolution CT in 14 patients with exogeneous allergic alveolitis (EAA) were analysed retrospectively. There were 8 patients with clinically subacute disease, 5 patients in a chronic stage and 1 patient with acute EAA. The appearances and their distribution were examined. Seven of the 8 patients in the subacute stage showed a ground glass pattern and multiple nodules of less than 2 mm. All patients in the chronic stage showed a combination of fine infiltrates, small nodules and irregular linear densities; distortion of the pulmonary pattern was present in 3 cases. The patient with acute EAA showed diffuse dense areas of consolidation in both lungs as well as multiple nodules and a ground glass pattern. The CT appearances of EAA correspond with the basic micropathology and, within the clinical context, permit diagnostic classification. (orig.).

  15. Imagens em 2D e 3D geradas pela TC Cone-Beam e radiografias convencionais: qual a mais confiável? 2D / 3D Cone-Beam CT images or conventional radiography: which is more reliable?

    Directory of Open Access Journals (Sweden)

    Carolina Perez Couceiro

    2010-10-01

    Full Text Available OBJETIVO: comparar a confiabilidade de identificação dos pontos visualizados sobre radiografias cefalométricas convencionais e sobre imagens geradas pela Tomografia Computadorizada Cone-Beam em 2D e 3D. MÉTODOS: o material constou de imagens obtidas através do tomógrafo computadorizado Cone-Beam, em norma lateral, em 2D e 3D, impressas em papel fotográfico; e radiografias cefalométricas laterais, realizadas na mesma clínica radiológica e no mesmo dia, de dois pacientes pertencentes aos arquivos do Curso de Especialização em Ortodontia da Faculdade de Odontologia da Universidade Federal Fluminense (UFF. Dez alunos do Curso de Especialização em Ortodontia da UFF identificaram pontos de referência sobre papel de acetato transparente e foram feitas medições das seguintes variáveis cefalométricas: ANB, FMIA, IMPA, FMA, ângulo interincisal, 1-NA (mm e ¯1-NB (mm. Em seguida, foram calculadas médias aritméticas, desvios-padrão e coeficientes de variância de cada variável para os dois pacientes. RESULTADOS E CONCLUSÃO: os valores das medições realizadas a partir de imagens em 3D apresentaram menor dispersão, sugerindo que essas imagens são mais confiáveis quanto à identificação de alguns pontos cefalométricos. Entretanto, como as imagens em 3D impressas utilizadas no presente estudo não permitiram a visualização de pontos intracranianos, torna-se necessário que softwares específicos sejam elaborados para que esse tipo de exame possa se tornar rotineiro na clínica ortodôntica.OBJECTIVE: To compare the reliability of two different methods used for viewing and identifying cephalometric landmarks, i.e., (a using conventional cephalometric radiographs, and (b using 2D and 3D images generated by Cone-Beam Computed Tomography. METHODS: The material consisted of lateral view 2D and 3D images obtained by Cone-Beam Computed Tomography printed on photo paper, and lateral cephalometric radiographs, taken in the same

  16. Economic evaluation comparing intraoperative cone beam CT-based navigation and conventional fluoroscopy for the placement of spinal pedicle screws: a patient-level data cost-effectiveness analysis.

    Science.gov (United States)

    Dea, Nicolas; Fisher, Charles G; Batke, Juliet; Strelzow, Jason; Mendelsohn, Daniel; Paquette, Scott J; Kwon, Brian K; Boyd, Michael D; Dvorak, Marcel F S; Street, John T

    2016-01-01

    Pedicle screws are routinely used in contemporary spinal surgery. Screw misplacement may be asymptomatic but is also correlated with potential adverse events. Computer-assisted surgery (CAS) has been associated with improved screw placement accuracy rates. However, this technology has substantial acquisition and maintenance costs. Despite its increasing usage, no rigorous full economic evaluation comparing this technology to current standard of care has been reported. Medical costs are exploding in an unsustainable way. Health economic theory requires that medical equipment costs be compared with expected benefits. To answer this question for computer-assisted spinal surgery, we present an economic evaluation looking specifically at symptomatic misplaced screws leading to reoperation secondary to neurologic deficits or biomechanical concerns. The study design was an observational case-control study from prospectively collected data of consecutive patients treated with the aid of CAS (treatment group) compared with a matched historical cohort of patients treated with conventional fluoroscopy (control group). The patient sample consisted of consecutive patients treated surgically at a quaternary academic center. The primary effectiveness measure studied was the number of reoperations for misplaced screws within 1 year of the index surgery. Secondary outcome measures included were total adverse event rate and postoperative computed tomography usage for pedicle screw examination. A patient-level data cost-effectiveness analysis from the hospital perspective was conducted to determine the value of a navigation system coupled with intraoperative 3-D imaging (O-arm Imaging and the StealthStation S7 Navigation Systems, Medtronic, Louisville, CO, USA) in adult spinal surgery. The capital costs for both alternatives were reported as equivalent annual costs based on the annuitization of capital expenditures method using a 3% discount rate and a 7-year amortization period

  17. CT urography

    Energy Technology Data Exchange (ETDEWEB)

    Korobkin, M. [Dept. of Radiology, Univ. of Michigan, Ann Arbor, MI (United States)

    2005-11-15

    With the advent of multidetector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract - the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mmin diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination - MDCTU. (orig.)

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... a relatively short time, especially when compared to magnetic resonance imaging (MRI). CT scanning is painless, noninvasive and accurate. A ... CT is less sensitive to patient movement than MRI. CT can be performed if you have an ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CT is less sensitive to patient movement than MRI. CT can be performed if you have an implanted medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate ...

  20. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT Scanning of the Abdomen and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed tomography, ... the body being studied. top of page How is the CT scan performed? The technologist begins by ...

  1. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... additional view capabilities. Modern CT scanners are so fast that they can scan through large sections of ... after the procedure? CT exams are generally painless, fast and easy. With multidetector CT, the amount of ...

  2. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Abdomen and Pelvis Computed tomography (CT) of the abdomen ... and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed tomography, more commonly known as a ...

  3. Abdominal and Pelvic CT

    Science.gov (United States)

    ... Professions Site Index A-Z Computed Tomography (CT) - Abdomen and Pelvis Computed tomography (CT) of the abdomen ... and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed tomography, more commonly known as a ...

  4. 颈内动脉颅内段常规头颅CT钙化斑块评分对其狭窄的筛检作用%Screening Effect of the Intracranial Internal Carotid Artery' s Plaque Calcium Score by Using Conventional Brain Unenhanced CT on Artery stenosis

    Institute of Scientific and Technical Information of China (English)

    陈立勋; 张婷; 赵衡; 肖文连; 吴晓东; 刘进才; 游咏

    2013-01-01

    目的 探讨常规头颅CT平扫对颈内动脉颅内段钙化斑块评分及对该段血管狭窄程度的筛检作用.方法 行头颈部CT动脉造影(含常规头颅CT平扫,CTA)的病例110例,按照目测和软件评分相结合的方法将斑块分为4级,选取能成功进行Agatston钙化评分的3、4级斑块并能进行CT动脉造影狭窄分析(AVA)的病例26例,记录斑块的Agatston钙化评分值;采用AVA软件分析该斑块的血管狭窄程度及相应的北美症状性颈动脉内膜切除术(NASCET)标准分级.结果 26例中,轻度狭窄18例,Agatston钙化评分值2.69±1.01;中度狭窄5例,Agatston 钙化评分值5.25±0.88;重度狭窄及闭塞3例,Agatston钙化评分值6.80±0.30.中、重度狭窄与轻度狭窄的血管斑块Agatston钙化评分差异有统计学意义(P<0.05),中、重度狭窄之间差异无统计学意义(P>0.05).狭窄程度与斑块的Agaston钙化评分正相关(r=0.938,P<0.05).结论 常规头颅CT平扫颈内动脉颅内段钙化斑块Agatston评分对该段血管狭窄程度有筛检作用,血管斑块Agatston钙化评分值5.25以上患者应进一步行CTA检查.%Aim To investigate the preliminary scanning significance of artery stenosis with intracranial internal carotid artery' s plaque calcium score using conventional brain unenhanced computed tomography (CT).Methods By retrospectively analyzing brain and neck CT artery imaging (including conventional brain unenhanced CT,CTA) of 110 cases,the intracranial internal carotid artery' s calcification were classified into 4 grades.Of them,there are 26 cases which can be successfully classified into 3/4 grade by Agatston Calcium Score and receive CT artery imaging analysis of vascular and artery (AVA) software.AVA software was used to analyse the calcification segment artery' s stenosis degree and its North American Symptomatic Carotid Endarterectomy Trial criteria (NASCET) classification.Results In the 26 cases,there are 18 cases of mild grade

  5. CT in vascular pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Bartolozzi, C.; Neri, E.; Caramella, D. [Diagnostic and Interventional Radiology Department of Oncology, University of Pisa, Via Roma 67, I-56100 Pisa (Italy)

    1998-06-02

    Since the introduction of helical scanners, CT angiography (CTA) has achieved an essential role in many vascular applications that were previously managed with conventional angiography. The performance of CTA is based on the accurate selection of collimation width, pitch, reconstruction spacing and scan delay, which must be modulated on the basis of the clinical issue. However, the major improvement of CT has been provided by the recent implementation of many post-processing techniques, such as multiplanar reformatting, shaded surface display, maximum intensity projections, 3D perspectives of surface and volume rendering, which simulate virtual intravascular endoscopy. The integration of the potentialities of the scanner and of the image processing techniques permitted improvement of: (a) the evaluation of aneurysms, dissection and vascular anomalies involving the thoracic aorta; (b) carotid artery stenosis; (c) aneurysms of abdominal aorta; (d) renal artery stenosis; (e) follow-up of renal artery stenting; and (f) acute or chronic pulmonary embolism. Our experience has shown that the assessment of arterial pathologies with CTA requires the integration of 3D post-processing techniques in most applications. (orig.) With 4 figs., 34 refs.

  6. Cine CT technique for dynamic airway studies

    Energy Technology Data Exchange (ETDEWEB)

    Ell, S.R.; Jolles, H.; Keyes, W.D.; Galvin, J.R.

    1985-07-01

    The advent of cine CT scanning with its 50-msec data acquisition time promises a much wider range of dynamic CT studies. The authors describe a method for dynamic evaluation of the extrathoracic airway, which they believe has considerable potential application in nonfixed upper-airway disease, such as sleep apnea and stridor of unknown cause. Conventional CT is limited in such studies by long data acquisition time and can be used to study only prolonged maneuvers such as phonation. Fluoroscopy and digital subtraction studies are limited by relatively high radiation dose and inability to image all wall motions simultaneously.

  7. Conventional Prompt Global Strike: Capabilities Today While Planning for Tomorrow

    Science.gov (United States)

    2012-03-19

    invest in a design that will allow new Virginia class submarines to be modified to carry more cruise missiles and develop an undersea conventional...fact_display.asp?cid=2200&tid=1300&ct=2 (accessed 3 February, 2012). Woolf , Amy. Conventional Warheads for Long-Range Ballistic Missiles: Background...M.html (accessed March 2, 2012). 6 John Hundley, Maj, USAF, Personal Interview 7 Amy F. Woolf , Conventional Warheads for Long-Range Ballistic

  8. The Hague Judgments Convention

    DEFF Research Database (Denmark)

    Nielsen, Peter Arnt

    2011-01-01

    The Hague Judgments Convention of 2005 is the first global convention on international jurisdiction and recognition and enforcement of judgments in civil and commercial matters. The author explains the political and legal background of the Convention, its content and certain crucial issues during...

  9. Intrahepatic arterioportal shunt: helical CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Quiroga, S.; Sebastia, M.C.; Moreiras, M.; Pallisa, E.; Rius, J.M.; Alvarez-Castells, A. [I. D. I. Hospital General i Universitari Vall d`Hebron, Barcelona (Spain). Servei de Radiodiagnostic

    1999-08-01

    The purpose of this study was to characterize the appearance of intrahepatic arterioportal shunts (APS) on two-phase helical CT, with emphasis on the importance of the hepatic arterial-dominant phase (HAP) to demonstrate perfusion disorders. We review eight cases of APS diagnosed by helical CT in our institution from January 1996 to March 1997 and describe the CT findings that established diagnosis. Five of them were confirmed by angiography. In seven (87.5 %) cases of APS we found early enhancement of the peripheral portal branches during the HAP of helical CT, whereas the superior mesenteric and splenic veins remained unenhanced. In five (62.5 %) cases of APS, transient, peripheral, triangular parenchymal enhancement was depicted during the HAP of helical CT; in four of these cases there was associated early enhancement of the portal branches. Helical CT can show perfusion alterations that might remain undiagnosed with conventional CT. An understanding of the hemodynamic changes that occur in APS can help in the interpretation of focal transient hepatic parenchymal enhancement and to differentiate APS from hypervascular tumors. We believe that the helical CT findings described herein are characteristic enough to suggest the diagnosis of APS. (orig.) With 3 figs., 1 tab., 16 refs.

  10. Combined PET/CT in oncology

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Keon Wook [National Cancer Center, Goyang (Korea, Republic of)

    2002-02-01

    Presently, PET is widely used in oncology, but suffers from limitations of poor anatomical information. To compensate for this weakness, a combined PET/CT has been developed by Professor Townsend at the University of Pittsburgh Medical Center. The prototype was designed as PET and CT components combined serially in a gantry. The CT images provide not only accurate anatomical location of the lesions but also transmission map for attenuation correction. More than 300 cancer patients have been studied with the prototype of PET/CT since July, 1998. The PET/TC studies affected the managements in about 20{approx}30% of cancer patients. These changes are a consequence of the more accurate localization of functional abnormalities, and the distinction of pathological from normal physiological uptake. Now a variety of combined PET/CT scanners with high-end PET and high-end CT components are commercially available. With the high speed of multi-slice helical CT, throughput of patient's increases compared to conventional PET. Although some problems (such as a discrepancy in breathing state between the two modalities) still remain, the role of PET/CT in oncology is very promising.

  11. Utility of bolus dynamic CT for the detection of hypervascular malignant hepatic tumors. Mainly referring to the comparison with delayed phase contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiromichi; Abe, Kimihiko [Tokyo Medical Coll. (Japan); Freeny, P.C.

    1996-03-01

    In order to analyze the usefulness of dynamic contrast-enhanced CT, 84 patients who had hepatocellular carcinoma or suspected hypervascular metastases were studied with conventional incremental dynamic CT (CID-CT) or double helical CT (DH-CT). Delayed phase contrast-enhanced CT studies were consecutively performed in all patients. Thirty-six of 84 patients had malignant hepatic neoplasms; six had hepatocellular carcinoma and 30 had metastatic tumors. At first, the detectability of hepatic lesions was evaluated with bolus dynamic CT and delayed phase CT. Dynamic CT has detected more lesions than delayed CT. Some hepatic lesions described as isodensity were missed on CID-CT. Therefore, delayed phase CT cannot be eliminated when CID-CT is performed. Secondly, hepatic lesion detectability with CID-CT was compared with that of DH-CT. DH-CT did not miss the hepatic lesions picked up by delayed phase CT and was expected to provide excellent detectability of hypervascular hepatic neoplasms. In addition, first helical CT showed most hepatic lesions as areas of obvious hyperdensity, while CID-CT did not show their correct vascularities. So-called hypervascular hepatic tumors, however, were not always hypervascular and were demonstrated as areas of iso-hypodensity even on initial helical scanning. Second helical CT was useful to detect these so-called hypervascular, but actually hypovascular lesions. In conclusion, dynamic CT was helpful in detecting hypervascular hepatic malignant neoplasms, and DH-CT was more accurate than-CID-CT for the detection of hepatic lesions and the evaluation of vascular lesion. (author).

  12. [Direct total body CT scan in multi-trauma patients

    NARCIS (Netherlands)

    Sierink, J.C.; Saltzherr, T.P.; Edwards, M.J.R.; Beuker, B.J.; Patka, P.; Goslings, J.C.; studiegroep, R.

    2012-01-01

    BACKGROUND: Immediate total body computed tomography (CT) scanning has become important in the early diagnostic phase of trauma care because of its high diagnostic accuracy. However, literature provides limited evidence whether immediate total body CT leads to better clinical outcome then convention

  13. Use of multidetector CT in the diagnosis of Moyamoya disease

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales-de Larrazabal, C.; Bhoey, H.K.; Lim, M.C.L. [Singapore Heart, Stroke and Cancer Centre, Ngee Ann City (Singapore)

    2005-07-01

    This article presents an adult case of moyamoya disease, diagnosed with CT angiography, and discusses the value of using a multidetector CT scan in the diagnosis of the disease. The patient's previous MRA and conventional angiography are used for comparison. (orig.)

  14. Use of computed tomography (CT) for urolithiasis in pediatric patients.

    Science.gov (United States)

    Gupta, Angela; Castellan, Miguel

    2015-01-01

    Numbers of annual CT examinations have been increasing incrementally each year during the last 10-20 years. Use of unenhanced CT has been increasingly used for evaluation of urolithiasis, and concerned had been raised about the risks of increased radiation exposure in pediatric patients. Sensitivities and specificity for ureteral stones on conventional CT have been reported up to 98-100%, respectively. Low dose protocols have been developed with the goal of reducing radiation dose with adequate image quality. Although the sensitivity and the specificity of CT is the highest, many can be diagnosed with combination of KUB and ultrasound. CT can be utilized in equivocal cases. Low-dose radiation CT protocols have been reported with high sensitivity and specificity and should be used in pediatric patients when a CT scan is needed.

  15. Epidurography: Comparison with CT-, helical-CT- and MR-Epidurography; Die Epidurographie: Vergleich mit CT-, Spiral-CT- und MR-Epidurographie

    Energy Technology Data Exchange (ETDEWEB)

    Tomczak, R. [Univ. Ulm, Klinik fuer Radiologie (Germany); Seeling, W. [Univ. Ulm, Klinik fuer Anaesthesiologie (Germany); Rieber, A. [Univ. Ulm, Klinik fuer Radiologie (Germany); Sokiranski, R. [Univ. Ulm, Klinik fuer Radiologie (Germany); Rilinger, N. [Univ. Ulm, Klinik fuer Radiologie (Germany); Brambs, H.J. [Univ. Ulm, Klinik fuer Radiologie (Germany)

    1996-08-01

    Purpose: The purpose of this study was to explain the origin of image patterns demonstrated by conventional epidurography, which is a controversially discussed topic in recent literature. Material and methods: After introduction of thoracic epidural catheters and iopamidol injection, conventional epidurography and CT-epidurography were performed on 25 preoperative patients. After injection of Gadolinium-DTPA MR-epidurography was performed in two patients treated for chronic pain with already introduced epidural catheters. Three volunteers also underwent identical imaging after introduction of thoracic epidural catheters and in addition helical-CT epidurography using twin-beam technology. Results: 40% of the patients demonstrated the railroad track phenomenon. We were able to prove that it is a sign of a rhythmically variable filling of segments of the lateral epidural space with contrast medium. 76% of the patients demonstrated no ventral epidural space at the thoracic level. 56% of the patients showed a medial area of translucence combined with a band-shaped contrasting of the epidural space in the standard ap view. This was proven in all cases to be a plica mediana dorsalis by CT. In all volunteers who underwent helical-CT and MR epidurography we observed the railroad track phenomenon and the filling defect of the anterior thoracic epidural space. Conclusion: CT epidurography is well suited for obtaining new insights into the interpretation of findings obtained by conventional epidurography. (orig.) [Deutsch] Zielsetzung: Das Ziel der vorliegenden Untersuchung war es, Kontrastmitteldarstellungen der konventionellen Epidurographie, die in der Literatur widerspruechlich diskutiert werden, durch CT- und MR-Epidurographie zu erklaeren. Material und Methoden: Nach der Injektion von jodhaltigem Kontrastmittel ueber einen epiduralen Katheter wurden bei 25 praeoperativen Patienten eine Epidurographie und eine CT-Epidurographie durchgefuehrt. Zwei Schmerzpatienten mit

  16. Varieties of conventional implicature

    Directory of Open Access Journals (Sweden)

    Eric Scott McCready

    2010-07-01

    Full Text Available This paper provides a system capable of analyzing the combinatorics of a wide range of conventionally implicated and expressive constructions in natural language via an extension of Potts's (2005 L_CI logic for supplementary conventional implicatures. In particular, the system is capable of analyzing objects of mixed conventionally implicated/expressive and at-issue type, and objects with conventionally implicated or expressive meanings which provide the main content of their utterances. The logic is applied to a range of constructions and lexical items in several languages. doi:10.3765/sp.3.8 BibTeX info

  17. CT and radiographic assessment of tube thoracostomy

    Energy Technology Data Exchange (ETDEWEB)

    Stark, D.D.; Federle, M.P.; Goodman, P.C.

    1983-08-01

    Conventional chest radiography and computed tomography (CT) were used to evaluate tube thoracostomy drainage of pleural empyema in 26 selected patients. Frontal radiographs alone were inadequate in the evaluation of thoracostomy tube placement, as only one of 21 malpositioned tubes was identified; however, when lateral radiographs were also obtained, eight of nine malpositioned tubes were identified. Suboptimal drainage due to malpositioning was demonstrated best by CT in all 21 cases. Prolongation of hospitalization, serious complications, and death correlated with failure of early tube thoracostomy drainage as demonstrated by CT. Routine frontal and lateral chest radiographs are recommended for all patients after thoracostomy tube placement for empyema. For selected patients with empyema, early use of CT to guide tube repositioning or thoracotomy may reduce morbidity and mortality and decrease hospital costs.

  18. Advances in CT imaging for urolithiasis

    Directory of Open Access Journals (Sweden)

    Yasir Andrabi

    2015-01-01

    Full Text Available Urolithiasis is a common disease with increasing prevalence worldwide and a lifetime-estimated recurrence risk of over 50%. Imaging plays a critical role in the initial diagnosis, follow-up and urological management of urinary tract stone disease. Unenhanced helical computed tomography (CT is highly sensitive (>95% and specific (>96% in the diagnosis of urolithiasis and is the imaging investigation of choice for the initial assessment of patients with suspected urolithiasis. The emergence of multi-detector CT (MDCT and technological innovations in CT such as dual-energy CT (DECT has widened the scope of MDCT in the stone disease management from initial diagnosis to encompass treatment planning and monitoring of treatment success. DECT has been shown to enhance pre-treatment characterization of stone composition in comparison with conventional MDCT and is being increasingly used. Although CT-related radiation dose exposure remains a valid concern, the use of low-dose MDCT protocols and integration of newer iterative reconstruction algorithms into routine CT practice has resulted in a substantial decrease in ionizing radiation exposure. In this review article, our intent is to discuss the role of MDCT in the diagnosis and post-treatment evaluation of urolithiasis and review the impact of emerging CT technologies such as dual energy in clinical practice.

  19. CT findings of acoustic neuroma

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Do Choul; Lee, Jae Mun; Shinn, Kyung Sub; Bahk, Yong Whee [Catholic Univ., Seoul (Korea, Republic of)

    1987-10-15

    Computed Tomography (CT) is very accurate in evaluating the location, size, shape and extension of acoustic neuroma. We analysed CT findings of 23 acoustic neuromas seen at Department of Radiology, Kangnam St. Mary's Hospital, Catholic University Medical College during the period of from January 1981 to June 1987. 1. Five (22%) were men and 18 (78%) were women with the high incidence occurring in the 4th and 5th decades. 2. Twenty two cases were diagnosed satisfactorily by CT examinations which included axial, coronal and reconstruction images. One with the smallest dimension of 8 mm in diameter could not be detected by the conventional CT scan. But is could be seen after metrizamide cisternography. mean size of the tumor masses was estimated 3.6 cm in diameter. 3. The shape of the tumor was oval in 50%, round in 27% and lobulated in 23%. The masses were presented as hypodense in 50%, isodense in 32% and hyperdense in 18%. All tumors were extended from the internal acoustic and toward the cerebellopontine angle. The internal acoustic canal was widened in 77%. Hydrocephalus was associated in 45%. Widening of cerebellopontine angle cistern was noted in 50%. 4. After contrast infusion the tumors were enhanced markedly in 45%, moderately in 32% and mildly in 23%. The enhanced pattern was homogeneous in 41%, mixed in 41% and rim in 18%. The margin of the tumors was sharply defined in 82%. The tumors were attached to the petrous bone with acute angle in 73%. Cystic change within the tumor was found in 27%. The peritumoral edema was noted in 45%. In conclusion, CT is of most effective modalities to evaluate size, shape, extent and internal architecture of acoustic neuroma as well as relationship with adjacent anatomic structures including the internal acoustic canal.

  20. Lens dosimetry during examination of the sella turcica: comparison between conventional tomography and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Louis, O.; Bette, L.; Noseda, A.

    1986-01-01

    Lens irradiation measurements were performed with thermo-luminescent lithium fluoride dosimeters during tomographic examinations of the sella turcica, simulated on a phantom head. Lens dosimetry during linear or hypocycloidal conventional tomography was compared with that during computed tomography (CT). Results showed that CT involved much lower radiation exposure to the lens than did conventional tomography and that the major part of the irradiation delivered by CT was related to axial scanning. Therefore, the major finding was that lens irradiation during CT of the sella can be kept at a particularly low level (< 1 m Gy/8 sections) when only coronal scanning is performed.

  1. Abdominal and Pelvic CT

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    Full Text Available ... the scanner at one time such as with MRI. If an intravenous contrast material is used, you ... CT is less sensitive to patient movement than MRI. CT can be performed if you have an ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT of the sinuses is primarily used ...

  4. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ...

  5. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ...

  6. Abdominal and Pelvic CT

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

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    Full Text Available ... the limitations of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

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    Full Text Available ... the cause of unexplained pain. CT scanning is fast, painless, noninvasive and accurate. In emergency cases, it ... additional view capabilities. Modern CT scanners are so fast that they can scan through large sections of ...

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  12. Abdominal and Pelvic CT

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  13. Computed Tomography (CT) -- Head

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  14. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  15. CT Grading of Otosclerosis

    National Research Council Canada - National Science Library

    Lee, T.C; Aviv, R.I; Chen, J.M; Nedzelski, J.M; Fox, A.J; Symons, S.P

    2009-01-01

    ...: The CT grading system for otosclerosis was proposed by Symons and Fanning in 2005. The purpose of this study was to determine if this CT grading system has high interobserver and intraobserver agreement...

  16. Abdominal and Pelvic CT

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    Full Text Available ... CT scanner technique will be adjusted to their size and the area of interest to reduce the ... Patient undergoing computed tomography (CT) scan View full size with caption Pediatric Content Some imaging tests and ...

  17. Computed Tomography (CT) -- Head

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    Full Text Available ... CT scanner technique will be adjusted to their size and the area of interest to reduce the ... Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... CT scanner technique will be adjusted to their size and the area of interest to reduce the ... Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and ...

  19. Abdominal and Pelvic CT

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    Full Text Available ... page How should I prepare for the CT scan? You should wear comfortable, loose-fitting clothing to ... studied. top of page How is the CT scan performed? The technologist begins by positioning you on ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  1. Abdominal and Pelvic CT

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits Viewing a CT scan, an experienced radiologist ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  2. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits A CT scan is one of the ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Magnetic Resonance Imaging ( ...

  4. Computed Tomography (CT) -- Head

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in ...

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Ultrasound - Abdomen X- ...

  6. Abdominal and Pelvic CT

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    Full Text Available ... CT scanning is fast, painless, noninvasive and accurate. In emergency cases, it can reveal internal injuries and ... generated during a CT scan can be reformatted in multiple planes, and can even generate three-dimensional ...

  7. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide ... clicking and whirring sounds as the CT scanner's internal parts, not usually visible to you, revolve around ...

  8. Abdominal and Pelvic CT

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    Full Text Available ... the cause of unexplained pain. CT scanning is fast, painless, noninvasive and accurate. In emergency cases, it ... additional view capabilities. Modern CT scanners are so fast that they can scan through large sections of ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... which may be causing hearing problems. determine whether inflammation or other changes are present in the paranasal ... CT scans . CT is not sensitive in detecting inflammation of the meninges —the membranes covering the brain. ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... a stroke. a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain cavities ( ... brain. assess aneurysms or arteriovenous malformations through a technique called CT angiography. For more information, see the ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... to urinate; however, this is actually a contrast effect and subsides quickly. When you enter the CT ...

  12. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... to urinate; however, this is actually a contrast effect and subsides quickly. When you enter the CT ...

  13. Cardiac CT Scan

    Science.gov (United States)

    ... combine these pictures to create a three-dimensional (3D) model of the whole heart. This imaging test ... findings from earlier chest x rays. Different CT scanners are used for different purposes. A multidetector CT ...

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT of the sinuses is primarily used ...

  16. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... benefits vs. risks? Benefits A CT scan is one of the safest means of studying the sinuses. ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  17. Gallstone ileus: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Delabrousse, E.; Bartholomot, B.; Sohm, O.; Kastler, B. [Dept. of Radiology A, CHU Jean Minjoz, University of Besancon (France); Wallerand, H. [Dept. of Surgery, CHU Jean Minjoz, University of Besancon (France)

    2000-06-01

    Gallstone ileus is a rare complication of recurrent gallstone cholecystitis. The classic radiographic triad of small bowel obstruction, pneumobilia and ectopic gallstone on abdominal plain radiograph is described with CT imaging. Because of the better resolution of CT compared with abdominal radiography and its recent accession to emergency use, radiologists should be aware of CT findings of gallstone ileus. We report a case in which gallstone ileus was initially diagnosed by CT. (orig.)

  18. Abdominal and Pelvic CT

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    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  19. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... a sudden severe headache. a blood clot or bleeding within the brain shortly after a patient exhibits symptoms of a stroke. a ... CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body after a CT examination. X-rays used in CT ...

  2. CT angiography and CT perfusion in acute ischemic stroke

    NARCIS (Netherlands)

    Seeters, T. van

    2016-01-01

    CT angiography and CT perfusion are used in patients with acute ischemic stroke for diagnostic purposes and to select patients for treatment. In this thesis, the reproducibility of CT angiography and CT perfusion is examined, the additional value of CT angiography and CT perfusion for stroke outcome

  3. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) ... are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a ...

  4. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... CT Angiography Video: Myelography Video: CT of the Heart Video: Radioiodine I-131 Therapy Radiology and You ... CT Angiography Video: Myelography Video: CT of the Heart Video: Radioiodine I-131 Therapy Radiology and You ...

  5. Multislice spiral CT of the paranasal sinuses; Mehrschicht-Spiral-CT der Nasennebenhoehlen: Erste Erfahrungen unter besonderer Beruecksichtigung der Strahlenexposition

    Energy Technology Data Exchange (ETDEWEB)

    Dammann, F.; Bode, A.; Heuschmid, M.; Kopp, A.; Georg, C.; Pereira, P.L.; Claussen, C.D. [Tuebingen Univ. (Germany). Radiologische Universitaetsklinik

    2000-08-01

    Purpose: To evaluate the potential of multislice CT in the diagnosis of the paranasal sinuses. Methods: Dose measurements were performed exposing an Alderson Rando phantom in a four-slice spiral CT (MS-CT) while applying a variety of scan parameters. Additionally, 30 consecutive patients underwent a transversal examination by the MS-CT using 1/1/3.5/0.5 mm spiral parameters and an additional transversal or coronal scan on a conventional single slice spiral CT (SS-CT) with 2/3/1 mm. Coronal reformations of the MS-CT were compared with the primary coronal SS-CT, or coronal reformations of the transversal SS-CT, respectively, with regard to image quality and depiction of relevant anatomical details of the region. Results: Superficial exposure values at the level of the eye lenses as well as for the thyroid gland were superior for MS-CT (3.62 mGy, and 0.12 mGy, resp.) as compared to SS-CT (2.96 mGy, and 0.07 mGy). Image quality was equal or superior for MS-CT as compared to SS-CT in all but one case. Drawbacks of SS-CT, such as dental amalgam artifacts, stair step artifacts or partial volume artifacts did not notably affect the coronal reformations of MS-CT. Conclusions: MS-CT seems to have the potential to replace primary coronal CT of the paranasal sinuses without any loss of image quality, but may even improve the overall diagnostic value. Radiation doses may still have to be reduced. (orig.) [German] Ziel: Erprobung eines Multislice-CT (MS-CT) zur Diagnostik der Nasennebenhoehlen (NNH). Methode: An einem Alderson Rando Phantom wurden Dosismessungen bei der Spiral-CT der NNH mit einem Mehrschicht-CT (MS-CT) unter Verwendung unterschiedlicher Scanparameter durchgefuehrt. Anschliessend wurden 30 konsekutive Patienten an dem MS-CT mit den Spiralparametern 1/1/3,5/0,5 mm und einem konventionellen Einzeilen Spiral-CT (SS-CT; 2/3/1 mm) untersucht. Die koronaren Rekonstruktionen der transversalen MS-CT wurden mit den koronaren Rekonstruktionen bzw. den primaeren koronaren

  6. Diagnostic significance of CT discography for lumbar disc herniation

    Energy Technology Data Exchange (ETDEWEB)

    Yanagida, Masaaki; Fujimura, Yoichi; Toyama, Yoshiaki; Koyanagi, Takahiro; Ueno, Mitsuru; Satomi, Kazuhiko (Keio Univ., Tokyo (Japan). School of Medicine); Hirabayashi, Kiyoshi

    1992-08-01

    CT discograms of 192 intervertebral disks from 107 patients with lumbar disk herniation were compared with conventional discograms and surgical findings. According to the shape and fissure of the nucleus pulposus, CT discographic appearance fell into (A) round or oval, (B) monoarborized, (C) polyarborized, and (D) diffuse. Types A, B, and D on CT discography well correlated with conventional discographic type I (round or oval) and II (bilocular), III (monoarborized), and V (diffuse), respectively. Correlation between type C on CT discography and type IV on conventional discography was only found in approximately 50% of the patients. According to the degree and feature of enlargement of the spinal nucleus, CT discographic appearance also fell into (a) the inner posterior margin, (b) the outer posterior margin with definite border and continuation, and (c) the outer posterior margin with no evidence of definite border or continuation. Type b corresponded well to protrusion and prolapse, and type c to extrusion and sequestration on surgery. This has important implications concerning the value of CT discography in detecting the presence or absence of perforation of the posterior longitudinal ligament. In comparison with the capability of conventional discography, CT discography may be more sensitive method for detecting transverse pathophysiology of the intervertebral disk. (N.K.).

  7. Moyamoya disease: diagnosis with three-dimensional CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, K. (Dept. of Radiology, National Defense Medical Coll., Saitama (Japan) Dept. of Radiology, Kyorin Univ. School of Medicine, Tokyo (Japan)); Makita, K. (Dept. of Radiology, National Defense Medical Coll., Saitama (Japan) Dept. of Radiology, Social Health Insurance Medical Center, Tokyo (Japan)); Furui, S. (Dept. of Radiology, National Defense Medical Coll., Saitama (Japan) Dept. of Diagnostic Radiology, Toranomon Kyosai Hospital, Tokyo (Japan))

    1994-08-01

    Our purpose was to assess the value of three-dimensional (3D) CT angiography in the diagnosis of moyamoya disease. We studied seven patients with moyamoya disease proved by conventional angiography. Three-dimensional (3D) CT angiography was performed using rapid sequence or helical (spiral) scanning in conjunction with a bolus injection of intravenous contrast medium. All seven patients could be diagnosed as having moyamoya disease on the basis of the following 3D CT angiographic findings: poor visualisation of the main trunks and/or major branches of anterior and middle cerebral arteries (7 patients); dilated leptomeningeal anastomotic channels from the posterior cerebral arteries (4); and demonstration of ''moyamoya vessels'' in the basal ganglia (2). Although conventional angiography remains the principal imaging technique for demonstrating anatomical changes in detail, less invasive 3D CT angiography provides a solid means of diagnosing moyamoya disease when it is suspected on CT, MRI, or clinical grounds. (orig.)

  8. The Geometry of Conventionality

    CERN Document Server

    Weatherall, James Owen

    2013-01-01

    Hans Reichenbach famously argued that the geometry of spacetime is conventional in relativity theory, in the sense that one can freely choose the spacetime metric so long as one is willing to postulate a "universal force field". Here we make precise a sense in which the field Reichenbach defines fails to be a "force". We then argue that there is an interesting and perhaps tenable sense in which geometry is conventional in classical spacetimes. We conclude with a no-go result showing that the variety of conventionalism available in classical spacetimes does not extend to relativistic spacetimes.

  9. Prenatal diagnosis of fetal skeletal dysplasia with 3D CT

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Osamu; Horiuchi, Tetsuya [National Center for Child Health and Development, Department of Radiology, Seatagaya-ku, Tokyo (Japan); Nishimura, Gen [Tokyo Metropolitan Children' s Medical Center, Department of Pediatric Imaging, Fuchu-shi, Tokyo (Japan); Sago, Haruhiko; Hayashi, Satoshi [National Center for Child Health and Development, Department of Perinatal Medicine and Maternal Care, Seatagaya-ku, Tokyo (Japan); Kosaki, Rika [National Center for Child Health and Development, Department of Strategic Medicine, Division of Clinical Genetics and Molecular Medicine, Seatagaya-ku, Tokyo (Japan)

    2012-07-15

    Clinical use of 3D CT for fetal skeletal malformations is controversial. The purpose of this study was to evaluate the efficacy of fetal 3D CT using three protocols with different radiation doses and through comparing findings between fetal CT and conventional postnatal radiographic skeletal survey. Seventeen fetuses underwent CT for suspected skeletal dysplasia. A relay of three CT protocols with stepwise dose-reduction were used over the study period. The concordance between the CT diagnosis and the final diagnosis was assessed. Ninety-three radiological findings identifiable on radiographs were compared with CT. Fetal CT provided the correct diagnosis in all 17 fetuses, the detectability rate of cardinal findings was 93.5 %. In 59 % of the fetuses an US-based diagnosis was changed prenatally due to CT findings. The estimated fetal radiation dose in the final protocol was 3.4 mSv (50 %) of the initial protocol, and this dose reduction did not result in degraded image quality. The capability of fetal CT to delineate the skeleton was almost the same as that of postnatal skeletal survey. The perinatal management was altered due to these more specific CT findings, which aided in counseling and in the management of the pregnancy. (orig.)

  10. Marketing cardiac CT programs.

    Science.gov (United States)

    Scott, Jason

    2010-01-01

    There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

  11. Conventional Spinal Anaesthesia

    African Journals Online (AJOL)

    patients scheduled for clcctive unilateral lower limb surgery. ... the conventional group were turned supine immediately after injection. Blood pressure, heart rate, respiratory rate and oxygen .... Characteristic Type of spinal anaesthcsia P-value.

  12. Performance of orthopantomography, planar scintigraphy, CT alone and SPECT/CT in patients with suspected osteomyelitis of the jaw

    Energy Technology Data Exchange (ETDEWEB)

    Bolouri, Carmen; Huellner, Martin W.; Veit-Haibach, Patrick; Perez-Lago, Marisol; Strobel, Klaus [Lucerne Cantonal Hospital, Department of Radiology and Nuclear Medicine, Lucerne (Switzerland); Merwald, Michael; Kuttenberger, Johannes [Lucerne Cantonal Hospital, Department of Oral and Maxillofacial Surgery, Lucerne (Switzerland); Seifert, Burkhardt [University of Zurich, Division of Biostatistics, Zurich (Switzerland)

    2013-03-15

    The aim of this study was to evaluate the performance of a novel flat-panel single photon emission computed tomography (SPECT)/CT in patients with suspicion of osteomyelitis (OM) of the jaw in comparison with conventional orthopantomography (OPT), planar bone scintigraphy (PS) and CT alone. Forty-two patients (21 female, 21 male, mean age 52, range 10-84 years) with suspected OM (n = 38) or exacerbation of a known OM (n = 4) were investigated with OPT, CT alone, PS and combined SPECT/CT. Images were separately reviewed by a nuclear physician/radiologist and jaw surgeon regarding presence of OM. Additionally, the different methods were rated regarding their usefulness for diagnosis (5-point scale: from 1 = diagnostic to 5 = useless). Biopsy served as the standard of reference in 30 patients and clinical/imaging follow-up of at least 6 months in 12 patients. In 35 of 42 patients the final diagnosis of OM was established according to the reference standard. Sensitivity, specificity and accuracy for OPT was 59, 100 and 66 %, for CT alone 77, 86 and 79 %, for PS 100, 71 and 95 % and for SPECT/CT 100, 86 and 98 %. SPECT/CT was significantly more accurate compared with CT alone (p = 0.0078) and OPT (p = 0.001). SPECT/CT was rated as the most useful imaging modality (mean value 1.2) compared with PS (2.2), CT (2.5) and OPT (3.2). SPECT/CT is an accurate method to assess the presence of OM of the jaw and superior to CT alone and OPT. SPECT/CT slightly improved the specificity of PS. However, SPECT/CT in this study was not significantly more accurate compared with PS and whether the advantages to the patient of a one-stop study as opposed to doing separate CT and PS justifies its routine use in terms of cost requires further study. (orig.)

  13. Demonstration of Achilles tendon on CT

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, M.; Rupp, N.; Lehner, K.; Paar, O.; Gradinger, R.; Karpf, P.M.

    1985-08-01

    Ligaments and tendons, including the Achilles tendon, show the highest density among normal soft tissue structures in the body. Traumatic and degenerative changes of the Achilles tendon are often associated with marked thickening and reduction in density associated with increased opacity of the space in front of the Achilles tendon. These changes are easily demonstrated by CT, whereas conventional radiological techniques only show non-specific changes. Twenty-five patients were examined, including nine with pain, seven following rupture of the Achilles tendon and nine post-operative controls; it was found that CT can add information important for the diagnosis and treatment planning of abnormalities of the Achilles tendon.

  14. DendroCT - Dendrochronology without damage

    DEFF Research Database (Denmark)

    Bill, Jan; Daly, Aoife; Johnsen, Øistein

    2012-01-01

    for dendrochronological analyses. In the scans it was possible to separate tree-rings down to 0.2. mm width, and it was possible to identify the sapwood-heartwood border when sufficient sapwood rings were present. It was found, however, that a visual inspection of the object was required to distinguish between sapwood...... and decayed wood. Comparisons between direct measurements of tree-rings and measurements based on CT-imagery revealed no significant differences. The scanning and subsequent dating of more than 90 objects showed that dendrochronological dating based on CT-scanning has a success rate equal to conventional...

  15. Blind Analysis of CT Image Noise Using Residual Denoised Images

    CERN Document Server

    Roychowdhury, Sohini; Alessio, Adam

    2016-01-01

    CT protocol design and quality control would benefit from automated tools to estimate the quality of generated CT images. These tools could be used to identify erroneous CT acquisitions or refine protocols to achieve certain signal to noise characteristics. This paper investigates blind estimation methods to determine global signal strength and noise levels in chest CT images. Methods: We propose novel performance metrics corresponding to the accuracy of noise and signal estimation. We implement and evaluate the noise estimation performance of six spatial- and frequency- based methods, derived from conventional image filtering algorithms. Algorithms were tested on patient data sets from whole-body repeat CT acquisitions performed with a higher and lower dose technique over the same scan region. Results: The proposed performance metrics can evaluate the relative tradeoff of filter parameters and noise estimation performance. The proposed automated methods tend to underestimate CT image noise at low-flux levels...

  16. CT scan in diagnosis of pituitary adenomas, 5. CT findings of GH secreting adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Sakoda, K.; Yonezawa, M.; Gen, M. (Hiroshima Univ. (Japan). School of Medicine)

    1981-10-01

    Clinical findings and radiological findings in 19 cases of GH secreting adenoma were reported. In diagnosis of GH secreting adenoma, conventional radiography and computed tomography of the sella turcica are useful. The CT of this kind of adenomas shows a characteristically higher x-ray absorption coefficient than other adenomas.

  17. Dual energy CT myelography after lumba osteosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Grams, A.E.; Gizewski, E.R. [Medical Univ. Innsbruck (Austria). Dept. of Neuroradiology; Sender, J.; Obert, M. [Univ. Hospital Giessen (Germany). Dept. of Neuroradiology; Mortiz, R.; Krombach, G.A. [Univ. Hospital Giessen (Germany). Dept. of Radiology; Stein, M. [Univ. Hospital Giessen (Germany). Dept. of Neurosurgery; Oertel, M. [Vogtland-Klinikum Plauen (Germany). Dept. of Neurosurgery; Schmidt, T. [Klinikum Wuppertal (Germany). Dept. of Neuroradiology

    2014-07-15

    The purpose of this study was to evaluate the benefits of CT myelography in the DE technique in patients with lumbar osteosynthesis. In 30 patients a DE-CT scan of the spine with tube voltages of 80 kV and 140 kV was performed and a virtual monochromatic series of 120 kV was generated after intrathecal contrast injection. The impact of metal artifacts on the spinal canal and the spinal foramina was evaluated. The visualization of nerve roots was compared between a VRT series of the dural sac and conventional myelography. With tube voltages of 140 kV, the artifacts were least pronounced. As no overlay disturbance was present, VRT visualization of the nerve roots was more reliable than conventional myelography. In patients after osteosynthesis, CT in the DE technique provides minimal artifact disturbance using a tube voltage of 140 kV. ''Virtual myelography'' seems to be superior to conventional myelography for the evaluation of nerve roots. This could reduce additional conventional radiography, may shorten the entire examination and radiation time and diminish unnecessary painful movements for the patient.

  18. Conventional versus virtual radiographs of the injured pelvis and acetabulum

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, Julius A.; Rao, Allison J.; Pouliot, Michael A.; Bellino, Michael [Stanford University School of Medicine, Department of Orthopaedic Surgery, Stanford, CA (United States); Beaulieu, Christopher [Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States)

    2015-09-15

    Evaluation of the fractured pelvis or acetabulum requires both standard radiographic evaluation as well as computed tomography (CT) imaging. The standard anterior-posterior (AP), Judet, and inlet and outlet views can now be simulated using data acquired during CT, decreasing patient discomfort, radiation exposure, and cost to the healthcare system. The purpose of this study is to compare the image quality of conventional radiographic views of the traumatized pelvis to virtual radiographs created from pelvic CT scans. Five patients with acetabular fractures and ten patients with pelvic ring injuries were identified using the orthopedic trauma database at our institution. These fractures were evaluated with both conventional radiographs as well as virtual radiographs generated from a CT scan. A web-based survey was created to query overall image quality and visibility of relevant anatomic structures. This survey was then administered to members of the Orthopaedic Trauma Association (OTA). Ninety-seven surgeons completed the acetabular fracture survey and 87 completed the pelvic fracture survey. Overall image quality was judged to be statistically superior for the virtual as compared to conventional images for acetabular fractures (3.15 vs. 2.98, p = 0.02), as well as pelvic ring injuries (2.21 vs. 1.45, p = 0.0001). Visibility ratings for each anatomic landmark were statistically superior with virtual images as well. Virtual radiographs of pelvic and acetabular fractures offer superior image quality, improved comfort, decreased radiation exposure, and a more cost-effective alternative to conventional radiographs. (orig.)

  19. PET/CT Artifacts

    OpenAIRE

    Blodgett, Todd M.; Mehta, Ajeet S.; Mehta, Amar S.; Laymon, Charles M; Carney, Jonathan; Townsend, David W.

    2011-01-01

    There are several artifacts encountered in PET/CT imaging, including attenuation correction (AC) artifacts associated with using CT for attenuation correction. Several artifacts can mimic a 2-deoxy-2-[18F] fluoro-D-glucose (FDG) avid malignant lesions and therefore recognition of these artifacts is clinically relevant. Our goal was to identify and characterize these artifacts and also discuss some protocol variables that may affect image quality in PET/CT.

  20. Importance of PET/CT for imaging of colorectal cancer; Stellenwert der PET/CT zur Bildgebung des kolorektalen Karzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Meinel, F.G.; Schramm, N.; Graser, A.; Reiser, M.F.; Rist, C. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Haug, A.R. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Klinik und Poliklinik fuer Nuklearmedizin, Muenchen (Germany)

    2012-06-15

    Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has emerged as a very useful imaging modality in the management of colorectal carcinoma. Data from the literature regarding the role of PET/CT in the initial diagnosis, staging, radiotherapy planning, response monitoring and surveillance of colorectal carcinoma is presented. Future directions and economic aspects are discussed. Computed tomography (CT), magnetic resonance imaging (MRI) and FDG-PET for colorectal cancer and endorectal ultrasound for rectal cancer. Combined FDG-PET/CT. While other imaging modalities allow superior visualization of the extent and invasion depth of the primary tumor, PET/CT is most sensitive for the detection of distant metastases of colorectal cancer. We recommend a targeted use of PET/CT in cases of unclear M staging, prior to metastasectomy and in suspected cases of residual or recurrent colorectal carcinoma with equivocal conventional imaging. The role of PET/CT in radiotherapy planning and response monitoring needs to be determined. Currently there is no evidence to support the routine use of PET/CT for colorectal screening, staging or surveillance. To optimally exploit the synergy between morphologic and functional information, FDG-PET should generally be performed as an integrated FDG-PET/CT with a contrast-enhanced CT component in colorectal carcinoma. (orig.) [German] Die Fluordesoxyglukose-Positronenemissionstomographie/Computertomographie (FDG-PET/CT) hat in den letzten Jahren zunehmende Bedeutung zur Bildgebung des kolorektalen Karzinoms erlangt. In diesem Beitrag stellen wir den Stand der Literatur zur Rolle der PET/CT bei Screening, Staging, Bestrahlungsplanung, Beurteilung eines Therapieansprechens und Nachsorge des kolorektalen Karzinoms dar. Zudem wird auf gesundheitsoekonomische Aspekte und zukuenftige Entwicklungen eingegangen. CT, MRT, FDG-PET, beim Rektumkarzinom zusaetzlich endorektaler Ultraschall. Kombinierte FDG-PET/CT. Waehrend

  1. Diagnosis of chondromalacia patellae using CT arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, M.; Karpf, P.M.; Bernett, P.

    1982-08-01

    Using anatomical specimens for experimental investigations, the physical-technical prerequisites for proper demonstration of the femoro-patellar articulation were determined and the following results obtained: hyaline cartilage possesses an attenuation value of 25-35 HU; artificial lesions from 1 mm. deep and 2 mm. wide minimum can be visualized; the use of positive contrast medium is best suited for demonstration of chondral lesions. In clinical practice we found that the various stages of cartilaginous degeneration peculiar to chondromalacia (Fruend I to III) are clearly demonstrated by CT arthrography. In CT the predisposing changes in the morphology of the patella and the femoro-patellar articulation are more precisely defined than in conventional tangential roentgenograms. In 69 cases the CT arthrographic findings could be verified at operation. However, the extent and severity of the lesions was, at times, underestimated.

  2. Spiral CT venography in central venous obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jin Wook; Park, Jae Hyung; Im, Jung Gi; Han, Moon Hee; Kim, In One; Chang, Kee Hyun; Yeon, Kyung Mo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of); Song, Chi Sung [Boramae Hospital, Seoul (Korea, Republic of)

    1998-11-01

    (s) respectively, CT venography was superior to direct catheter venography for evaluating the extent and cause of obstruction and collateral circulation. For the evaluation of severity of obstruction, CT and direct catheter venography were equal. In patients with suspected central venous obstruction, spiral CT venography can be an alternative to replace not only conventional CT but also direct contrast venography.=20.

  3. Low-dose non-enhanced CT versus full-dose contrast-enhanced CT in integrated PET/CT studies for the diagnosis of uterine cancer recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, Kazuhiro [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Suzuki, Kayo [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Nakamoto, Yuji [Kyoto University Hospital, Department of Diagnostic Radiology, Kyoto (Japan); Onishi, Yumiko; Sakamoto, Setsu; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Senda, Michio [Institute of Biomedical Research and Innovation, Department of Molecular Imaging, Kobe (Japan); Kita, Masato [Kobe City Medical Center General Hospital, Department of Obstetrics and Gynecology, Kobe (Japan)

    2010-08-15

    To evaluate low-dose non-enhanced CT (ldCT) and full-dose contrast-enhanced CT (ceCT) in integrated {sup 18}F-fluorodeoxyglucose (FDG) PET/CT studies for restaging of uterine cancer. A group of 100 women who had undergone treatment for uterine cervical (n=55) or endometrial cancer (n=45) underwent a conventional PET/CT scans with ldCT, and then a ceCT scan. Two observers retrospectively reviewed and interpreted the PET/ldCT and PET/ceCT images in consensus using a three-point grading scale (negative, equivocal, or positive) per patient and per lesion. Final diagnoses were obtained by histopathological examination, or clinical follow-up for at least 6 months. Patient-based analysis showed that the sensitivity, specificity and accuracy of PET/ceCT were 90% (27/30), 97% (68/70) and 95% (95/100), respectively, whereas those of PET/ldCT were 83% (25/30), 94% (66/70) and 91% (91/100), respectively. Sensitivity, specificity and accuracy did not significantly differ between two methods (McNemar test, p=0.48, p=0.48, and p=0.13, respectively). There were 52 sites of lesion recurrence: 12 pelvic lymph node (LN), 11 local recurrence, 8 peritoneum, 7 abdominal LN, 5 lung, 3 supraclavicular LN, 3 liver, 2 mediastinal LN, and 1 muscle and bone. The grading results for the 52 sites of recurrence were: negative 5, equivocal 0 and positive 47 for PET/ceCT, and negative 5, equivocal 4 and positive 43 for PET/ldCT, respectively. Four equivocal regions by PET/ldCT (local recurrence, pelvic LN metastasis, liver metastasis and muscle metastasis) were correctly interpreted as positive by PET/ceCT. PET/ceCT is an accurate imaging modality for the assessment of uterine cancer recurrence. Its use reduces the frequency of equivocal interpretations. (orig.)

  4. Comparison of Conventional Versus Spiral Computed Tomography with Three Dimensional Reconstruction in Chronic Otitis Media with Ossicular Chain Destruction

    Directory of Open Access Journals (Sweden)

    Naghibi

    2015-12-01

    Full Text Available Background Chronic otitis media (COM can be treated with tympanoplasty with or without mastoidectomy. In patients who have undergone middle ear surgery, three-dimensional spiral computed tomography (CT scan plays an important role in optimizing surgical planning. Objectives This study was performed to compare the findings of three-dimensional reconstructed spiral and conventional CT scan of ossicular chain study in patients with COM. Patients and Methods Fifty patients enrolled in the study underwent plane and three dimensional CT scan (PHILIPS-MX 8000. Ossicles changes, mastoid cavity, tympanic cavity, and presence of cholesteatoma were evaluated. Results of the two methods were then compared and interpreted by a radiologist, recorded in questionnaires, and analyzed. Logistic regression test and Kappa coefficient of agreement were used for statistical analyses. Results Sixty two ears with COM were found in physical examination. A significant difference was observed between the findings of the two methods in ossicle erosion (11.3% in conventional CT vs. 37.1% in spiral CT, P = 0.0001, decrease of mastoid air cells (82.3% in conventional CT vs. 93.5% in spiral CT, P = 0.001, and tympanic cavity opacity (12.9% in conventional CT vs. 40.3% in spiral CT, P=0.0001. No significant difference was observed between the findings of the two methods in ossicle destruction (6.5% conventional CT vs. 56.4% in spiral CT, P = 0.125, and presence of cholesteatoma (3.2% in conventional CT vs. 42% in spiral CT, P = 0.172. In this study, spiral CT scan demonstrated ossicle dislocation in 9.6%, decrease of mastoid air cells in 4.8%, and decrease of volume in the tympanic cavity in 1.6%; whereas, none of these findings were reported in the patients' conventional CT scans. Conclusion Spiral-CT scan is superior to conventional CT in the diagnosis of lesions in COM before operation. It can be used for detailed evaluation of ossicular chain in such patients.

  5. Spiral CT during pharmacoangiography with angiotensin II in patients with pancreatic disease. Technique and diagnostic efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, C.; Mihara, N.; Hosomi, N.; Inoue, E.; Fujita, M. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Diagnostic Radiology; Ohigashi, H.; Ishikawa, O. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Surgery; Nakaizumi, A. [Osaka Medical Center for Cancer and Cardiovascular Deseases (Japan). Dept. of Internal Medicine; Ishiguro, S. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Pathology

    1998-03-01

    Purpose: To compare the diagnostic efficacy of pancreatic pharmacoangiographic CT using angiotensin II with conventional angiographic CT. Material and Methods: Eighteen patients with space-occupying pancreatic disease were examined in this study. Pharmacoangiographic CT was performed with a 1-3-{mu}/6-ml solution of angiotensin II injected through a catheter into the celiac artery during spiral CT. Results: In 17 of the 18 (94%) patients, the area of pancreatic parenchymal enhancement was the same or larger at pharmacoangiographic CT than at conventional angiographic CT. The attenuation value of the pancreatic parenchyma was significantly increased at pharmacoangiographic CT (p=0.0010). Although the attenuation value of tumors was also increased on images obtained after the injection of angiotensin II, the tumor-to-pancreas contrast was significantly greater at pharmacoangiographic CT (p=0.0479). The mean differences in attenuation between tumor and pancreas at angiographic CT with and without angiotensin II were respectively 182 HU and 115 HU. Conclusion: Pharmacoangiographic CT with angiotensin II proved superior to conventional angiographic CT in the diagnosis of pancreatic disease. We therefore recommend it as a supplementary technique at the angiographic examination of patients with suspected pancreatic tumor. (orig.).

  6. CT of Gastric Emergencies.

    Science.gov (United States)

    Guniganti, Preethi; Bradenham, Courtney H; Raptis, Constantine; Menias, Christine O; Mellnick, Vincent M

    2015-01-01

    Abdominal pain, nausea, and vomiting are common presenting symptoms among adult patients seeking care in the emergency department, and, with the increased use of computed tomography (CT) to image patients with these complaints, radiologists will more frequently encounter a variety of emergent gastric pathologic conditions on CT studies. Familiarity with the CT appearance of emergent gastric conditions is important, as the clinical presentation is often nonspecific and the radiologist may be the first to recognize gastric disease as the cause of a patient's symptoms. Although endoscopy and barium fluoroscopy remain important tools for evaluating patients with suspected gastric disease in the outpatient setting, compared with CT these modalities enable less comprehensive evaluation of patients with nonspecific complaints and are less readily available in the acute setting. Endoscopy is also more invasive than CT and has greater potential risks. Although the mucosal detail of CT is relatively poor compared with barium fluoroscopy or endoscopy, CT can be used with the appropriate imaging protocols to identify inflammatory conditions of the stomach ranging from gastritis to peptic ulcer disease. In addition, CT can readily demonstrate the various complications of gastric disease, including perforation, obstruction, and hemorrhage, which may direct further clinical, endoscopic, or surgical management. We will review the normal anatomy of the stomach and discuss emergent gastric disease with a focus on the usual clinical presentation, typical imaging appearance, and differentiating features, as well as potential imaging pitfalls.

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  8. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  10. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... the best way to see if treatment is working or if a finding is stable or changed over time. top of page What are the benefits vs. risks? Benefits A CT scan is one of the safest means of studying the sinuses. CT is the most reliable imaging ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... you have a hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer you some medication to help you tolerate the CT scanning procedure. If an ...

  12. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... you have a hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer you some medication to help you tolerate the CT scanning procedure. If an ...

  13. Computed Tomography (CT) -- Head

    Science.gov (United States)

    ... of a stroke. a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain ... be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... does the equipment look like? The CT scanner is typically a ...

  14. Importance of SPECT/CT for resolving diseases of the jaw; Stellenwert der SPECT/CT zur Abklaerung von Kiefererkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, K.; Huellner, M.W.; Bolouri, C.; Veit-Haibach, P.; Sol Perez-Lago, M. del [Luzerner Kantonsspital, Institut fuer Nuklearmedizin und Roentgendiagnostik, Luzern (Switzerland); Merwald, M.; Kuttenberger, J. [Luzerner Kantonsspital, Klinik fuer Mund-, Kiefer- und Gesichtschirurgie, Luzern (Switzerland)

    2012-07-15

    Diseases of the jaw, such as osteomyelitis, condylar hyperactivity and tumors need adequate imaging to evaluate the extension and activity for therapy planning. Conventional planar scintigraphy, orthopantomography, computed tomography (CT) and magnetic resonance imaging (MRI) can be used for the evaluation of jaw diseases. Single photon emission computed tomography/computed tomography (SPECT/CT) provides metabolic and morphologic information in one imaging step and is becoming increasingly more available in larger hospitals. The SPECT/CT is superior to planar scintigraphy alone, CT and orthopantomography in the evaluation of the extension and activity of osteomyelitis and jaw tumors. In our hospital SPECT/CT has replaced the other imaging modalities in the evaluation of osteomyelitis and condylar hyperactivity. If available SPECT/CT should be performed for the evaluation of osteomyelitis of the jaw. (orig.) [German] Kiefererkrankungen wie Osteomyelitis, kondylaere Hyperaktivitaet und Kiefertumoren benoetigen eine exakte bildgebende Abklaerung, um die Therapie adaequat planen zu koennen. Die klassische planare Skelettszintigraphie, Orthopantomographie, CT und MRT koennen zur Abklaerung von Kiefererkrankungen eingesetzt werden. Die ''single photon emission computed tomography''/CT (SPECT/CT) bietet metabolische und morphologische Informationen in einem Untersuchungsgang und ist zunehmend in groesseren Kliniken verfuegbar. Die SPECT/CT ist zur Beurteilung der Ausbreitung und Aktivitaet einer Osteomyelitis und von Kiefertumoren der planaren Szintigraphie alleine, der CT und der Orthopantomographie ueberlegen. In unserer Klinik hat die SPECT/CT die bisherigen Verfahren zur Beurteilung der Kieferosteomyelitis und kondylaeren Hyperaktivitaet abgeloest. Sofern verfuegbar, sollte zur Abklaerung einer Kieferosteomyelitis die SPECT/CT eingesetzt werden. (orig.)

  15. CT of tracheal agenesis

    Energy Technology Data Exchange (ETDEWEB)

    Strouse, Peter J.; Hernandez, Ramiro J. [C.S. Mott Children' s Hospital, Department of Radiology, Ann Arbor, MI (United States); Newman, Beverley [Children' s Hospital of Pittsburgh, PA (United States). Department of Pediatric Radiology; Afshani, Ehsan [Children' s Hospital of Buffalo, NY (United States). Departments of Radiology and Pediatrics; Bommaraju, Mahesh [Women' s and Children' s Hospital of Buffalo, Division of Neonatology, University Pediatrics Associates, Buffalo, NY (United States)

    2006-09-15

    Tracheal agenesis is a rare and usually lethal anomaly. In the past, opaque contrast medium was injected via the esophagus to demonstrate the anatomy. To demonstrate the utility of helical and multidetector CT in delineating the aberrant anatomy in newborns with tracheal agenesis. Four newborns with tracheal agenesis were identified from three institutions. Imaging studies and medical records were reviewed. Each child was imaged with chest radiography. One child was imaged on a single-detector helical CT scanner and the other three on multidetector scanners. Helical and multidetector CT with 2D and 3D reconstructions clearly delineated the aberrant tracheobronchial and esophageal anatomy in each infant. Minimum intensity projection reformatted CT images were particularly helpful. One infant each had type I and type II tracheal agenesis. Two infants had type III tracheal agenesis. All four infants died. CT is a useful tool for delineating the aberrant anatomy of newborns with tracheal agenesis and thus helps in making rational clinical decisions. (orig.)

  16. Conventional cerebrospinal fluid scanning

    Energy Technology Data Exchange (ETDEWEB)

    Schicha, H.

    1985-06-01

    Conventional cerebrospinal fluid scanning (CSF scanning) today is mainly carried out in addition to computerized tomography to obtain information about liquor flow kinetics. Especially in patients with communicating obstructive hydrocephalus, CSF scanning is clinically useful for the decision for shunt surgery. In patients with intracranial cysts, CSF scanning can provide information about liquor circulation. Further indications for CSF scanning include the assessment of shunt patency especially in children, as well as the detection and localization of cerebrospinal fluid leaks.

  17. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... CT is less sensitive to patient movement than MRI. CT can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging provides real-time imaging, making it ...

  18. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  19. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? CT is used to help diagnose a ... the CT examination. top of page What does the equipment look like? The CT scanner is typically ...

  20. Children's (Pediatric) CT (Computed Tomography)

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  1. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ...

  2. Phase-contrast X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [Hitachi Ltd., Saitama (Japan). Advanced Research Laboratory; Takeda, Tohoru; Itai, Yuji

    1995-12-01

    Phase-contrast X-ray computed tomography (CT) enabling the observation of biological soft tissues without contrast enhancement has been developed. The X-ray phase shift caused by an object is measured and input to a standard CT reconstruction algorithm. A thousand times increase in the image sensitivity to soft tissues is achieved compared with the conventional CT using absorption contrast. This is because the X-ray phase shift cross section of light elements is about a thousand times larger than the absorption cross section. The phase shift is detected using an X-ray interferometer and computer analyses of interference patterns. Experiments were performed using a synchrotron X-ray source. Excellent image sensitivity is demonstrated in the observation of cancerous rabbit liver. The CT images distinguish cancer lesion from normal liver tissue and, moreover, visualize the pathological condition in the lesion. Although the X-ray energy employed and the present observation area size are not suitable for medical applications as they are, phase-contrast X-ray CT is promising for investigating the internal structure of soft tissue which is almost transparent for X-rays. The high sensitivity also provides the advantage of reducing X-ray doses. (author).

  3. Assessment of lung tumor response by perfusion CT.

    Science.gov (United States)

    Coche, E

    2013-01-01

    Perfusion CT permits evaluation of lung cancer angiogenesis and response to therapy by demonstrating alterations in lung tumor vascularity. It is advocated that perfusion CT performed shortly after initiating therapy may provide a better evaluation of physiological changes rather than the conventional size assessment obtained with RECIST. The radiation dose,the volume of contrast medium delivered to the patient and the reproducibility of blood flow parameters remain an issue for this type of investigation.

  4. CT vaginography: a new CT technique for imaging of upper and middle vaginal fistulas.

    Science.gov (United States)

    Botsikas, Diomidis; Pluchino, Nicola; Kalovidouri, Anastasia; Platon, Alexandra; Montet, Xavier; Dallenbach, Patrick; Poletti, Pierre-Alexandre

    2017-05-01

    Different types of vaginal fistulas is a relatively uncommon condition in the Western world but very frequent in developing countries. In the past, conventional vaginography was the radiological examination of choice for exploring this condition. CT and MRI are now both used for this purpose. Our objective was to test the feasibility and to explore the potential role of a new CT imaging technique implementing vaginal introitus obstruction and opacification of the vagina with iodine contrast agent, to show patency of a fistula. We describe the technical protocol of CT-vaginography as performed in Geneva University Hospitals, including vaginal catheterization with a Foley catheter and obstruction of the introitus by inflating the balloon of the catheter. We also report three cases of patients with suspected vaginal fistula who underwent CT-vaginography. The examinations were technically successful. In one patient, it revealed the presence of fistulous pathways from the vaginal fornix along the bilateral infected surgical prostheses. In a second patient, it showed a fistula between the vagina and the necrotic cavity of a recurrent cervical cancer. In a third patient, it proved the absence of a suspected vaginal fistula. CT-vaginography is a technically feasible CT protocol that provides anatomical and functional information on clinically suspected vaginal fistulas. Advances in knowledge: After the abandon of conventional vaginography in the era of transaxial imaging, the current modalities of imaging vaginal fistulas provide excellent anatomical detail but less functional information concerning the permeability of a vaginal fistulous pathway. We propose the use of CT-vaginography, a technical protocol that we describe in detail.

  5. Clinical application of FDG-PET/CT in metastatic infections.

    Science.gov (United States)

    Kouijzer, Ilse J; Vos, Fidel J; Bleeker-Rovers, Chantal P; Oyen, Wim J

    2017-06-01

    FDG-PET/CT has proven its clinical value and cost-effectiveness in diagnosing metastatic infections in patients with Gram-positive bacteremia. In identification of metastatic foci, FDG-PET/CT is useful as a screening method when localizing symptoms are absent because it provides whole-body coverage. FDG-PET/CT detects early metabolic activity rather than the late anatomical changes as visualized by computed tomography and magnetic resonance imaging. FDG-PET/CT allows more precise localization of infection within a shorter time span between injection and diagnosis as compared to conventional nuclear imaging. This review focuses on the clinical application of imaging of metastatic infectious diseases, with an emphasis on FDG-PET/CT putting it in perspective with other imaging modalities.

  6. Computer tomographic patterns in extrinsic allergic alveolitis - a comparison with conventional radiological findings

    Energy Technology Data Exchange (ETDEWEB)

    Hieckel, H.G.; Mueller, S.; Luening, M.

    1986-10-01

    Seventeen patients with extrinsic allergic alveolitis or bird-fancier's lung were examined by standard radiological techniques and classified after Hapke's classification. In addition, the patients were examined by CT. The CT patterns have been analysed and compared with standard radiological findings. The methodological advantages of CT are discussed. Radiological investigation is of limited value in the diagnosis of extrinsic allergic alveolitis. Conventional radiography remains the standard of initial X-ray examination. In early cases, however, CT may be a valuable addition within the diagnostic strategy of a diagnostic imaging department.

  7. Helical CT in the diagnosis of acute lower gastrointestinal haemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Sabharwal, Rohan [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia); Vladica, Philip [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia)]. E-mail: rpvl@imag.wsahs.nsw.gov.au; Chou, Roger [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia); Law, W. Phillip [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia)

    2006-05-15

    Introduction: A pilot study to evaluate helical computer tomography (CT) as a diagnostic tool for acute lower gastrointestinal tract (GIT) bleeding. CT was compared to conventional angiography (CA) and colonoscopy for the diagnosis and detection of bleeding site in suspected cases of acute lower GIT bleeding. Methods: Seven patients presenting with acute lower GIT bleeding, between June and November 2002, underwent CT examinations. All of these seven patients underwent CA following CT. Emergency colonoscopies were performed on five patients investigated with both CT and CA. Median delay from the most recent episode of hematochezia to CT was two and a half hours, to CA was 3 h, and to colonoscopy was 4 h. None of the patients underwent nuclear medicine (NM) bleeding studies. Results: Haemoglobin drop in all patients was greater than 15 g/L in the first 24 h of presentation. The mean age was 68.86 years (range, 49-83 years). Comparing CT and CA, there were four concordant and three discordant results. Both modalities had concordant findings of two active bleeding sites, one non-bleeding rectal tumour, and one negative case result. In three patients, the source of bleeding was found on CT whereas CA was negative. Emergency colonoscopies performed in all of these three patients confirmed blood in the colon/ileum. Conclusion: Early experience suggests that CT is a safe, convenient and accurate diagnostic tool for acute lower GIT haemorrhage. It raises questions regarding the sensitivity of CA. A new management algorithm for acute lower GIT haemorrhage using CT as the pre-CA screening tool is being proposed based on the preliminary findings. Positive CT will allow directed therapeutic angiography, while negative CT will triage patients into alternative management pathways.

  8. Importance of SPECT/CT for knee and hip joint prostheses; Stellenwert der SPECT/CT bei Knie- und Hueftgelenkprothesen

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, K.; Steurer-Dober, I.; Huellner, M.W.; Veit-Haibach, P.; Allgayer, B. [Luzerner Kantonsspital (Switzerland). Institut fuer Nuklearmedizin und Roentgendiagnostik

    2012-07-15

    Complications, such as loosening or infections are common problems after hip or knee arthroplasty. If conventional X-rays are equivocal bone scintigraphy is the classical second-line imaging modality. Single photon emission computed tomography/computed tomography (SPECT/CT) offers metabolic and morphologic information in one imaging step and is becoming increasingly more available in larger hospitals. The SPECT/CT procedure is a promising method and is increasingly being used in daily routine to evaluate joint arthroplasty. The additional benefit compared with classical conventional bone scintigraphy has to be evaluated in further prospective studies. In our hospital SPECT/CT regularly gives important additional information regarding prosthetic joint complications. SPECT/CT is increasingly being used as the second step imaging standard modality if conventional X-rays are equivocal. (orig.) [German] Komplikationen wie Lockerung und Infekt stellen ein haeufiges Problem nach Hueft- und Kniegelenkprothesen dar. Wenn die konventionelle Roentgenaufnahme nicht zum Ziel fuehrt, ist die klassische konventionelle Skelettszintigraphie die am haeufigsten verwendete ''Second-line''-Bildgebung. Die ''single photon emission computed tomography''/CT (SPECT/CT) bietet metabolische und morphologische Informationen bzgl. Prothesenkomplikationen in einem Untersuchungsgang und ist zunehmend in groesseren Kliniken verfuegbar. Die SPECT/CT ist eine viel versprechende Methode und wird im klinischen Alltag bei der Evaluation von Gelenkprothesen zunehmend eingesetzt. Es sind noch mehr prospektive Studien noetig, um die Leistungsfaehigkeit und den Zusatznutzen gegenueber der klassischen Szintigraphie zu evaluieren. In unserer Klinik wird die Knochenszintigraphie bei der Abklaerung von Prothesenkomplikationen zumeist mit einer SPECT/CT kombiniert und liefert regelmaessig wichtige Zusatzinformationen. Die SPECT/CT entwickelt sich zunehmend zum Standard

  9. Conventional and unconventional superconductivity

    Science.gov (United States)

    Fernandes, R. M.

    2012-02-01

    Superconductivity has been one of the most fruitful areas of research in condensed matter physics, bringing together researchers with distinct interests in a collaborative effort to understand from its microscopic basis to its potential for unprecedented technological applications. The concepts, techniques, and methods developed along its centennial history have gone beyond the realm of condensed matter physics and influenced the development of other fascinating areas, such as particle physics and atomic physics. These notes, based on a set of lectures given at the 2011 Advanced Summer School of Cinvestav, aim to motivate the young undergraduate student in getting involved in the exciting world of conventional and unconventional superconductors.

  10. Strategic interaction and conventions

    Directory of Open Access Journals (Sweden)

    Espinosa, María Paz

    2012-03-01

    Full Text Available The scope of the paper is to review the literature that employs coordination games to study social norms and conventions from the viewpoint of game theory and cognitive psychology. We claim that those two alternative approaches are in fact complementary, as they provide different insights to explain how people converge to a unique system of self-fulfilling expectations in presence of multiple, equally viable, conventions. While game theory explains the emergence of conventions relying on efficiency and risk considerations, the psychological view is more concerned with frame and labeling effects. The interaction between these alternative (and, sometimes, competing effects leads to the result that coordination failures may well occur and, even when coordination takes place, there is no guarantee that the convention eventually established will be the most efficient.

    El objetivo de este artículo es presentar la literatura que emplea los juegos de coordinación para el estudio de normas y convenciones sociales, que se han analizado tanto desde el punto de vista de la teoría de juegos como de la psicología cognitiva. Argumentamos en este trabajo que estos dos enfoques alternativos son en realidad complementarios, dado que ambos contribuyen al entendimiento de los procesos mediante los cuales las personas llegan a coordinarse en un único sistema de expectativas autorrealizadas, en presencia de múltiples convenciones todas ellas igualmente viables. Mientras que la teoría de juegos explica la aparición de convenciones basándose en argumentos de eficiencia y comportamientos frente al riesgo, el enfoque de la psicología cognitiva utiliza en mayor medida consideraciones referidas al entorno y naturaleza de las decisiones. La interacción entre estos efectos diferentes (y en ocasiones, rivales desemboca con frecuencia en fallos de coordinación y, aun cuando la coordinación se produce, no hay garantía de que la convención en vigor sea la m

  11. Current Roles and Future Applications of Cardiac CT: Risk Stratification of Coronary Artery Disease

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yeonyee Elizabeth [Department of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam 463-707 (Korea, Republic of); Lim, Tae-Hwan [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736 (Korea, Republic of)

    2014-07-01

    Cardiac computed tomography (CT) has emerged as a noninvasive modality for the assessment of coronary artery disease (CAD), and has been rapidly integrated into clinical cares. CT has changed the traditional risk stratification based on clinical risk to image-based identification of patient risk. Cardiac CT, including coronary artery calcium score and coronary CT angiography, can provide prognostic information and is expected to improve risk stratification of CAD. Currently used conventional cardiac CT, provides accurate anatomic information but not functional significance of CAD, and it may not be sufficient to guide treatments such as revascularization. Recently, myocardial CT perfusion imaging, intracoronary luminal attenuation gradient, and CT-derived computed fractional flow reserve were developed to combine anatomical and functional data. Although at present, the diagnostic and prognostic value of these novel technologies needs to be evaluated further, it is expected that all-in-one cardiac CT can guide treatment and improve patient outcomes in the near future.

  12. CT scan of choristoma

    Energy Technology Data Exchange (ETDEWEB)

    Moriki, A.; Morimoto, M.; Sada, Y.; Kurisaka, M.; Mori, K.

    1987-02-01

    Choristoma is a rare tumor that occurs in the pituitary gland. The case presented here is a 44-year-old male. A plain CT scan demonstrated a slight high-density mass near the posterior clinoid of the sella turcica, while a moderate and homogeneous enhancing effect and a clear borderline were shown by an enhanced CT scan. A cornal CT scan study showed that the tumor extended from the intrasellar to the suprasellar region. The diagnosis of choristoma was made by means of histology.

  13. Diagnostic Performance of CT Colonography for the Detection of Colorectal Polyps

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Ji Young; Ro, Hee Jeong; Choi, Jung Bin; Chung, Ji Eun; Kim, Yong Jin; Suh, Won Hyuck; Lee, Jong Kyun [Song-Do Hospital, Seoul (Korea, Republic of); Park, Jong Beom [East- West Neo Medical Center, Kyung Hee University, Seoul (Korea, Republic of)

    2007-12-15

    To investigate the diagnostic value of CT colonography for the detection of colorectal polyps. From December 2004 to December 2005, 399 patients underwent CT colonography and follow-up conventional colonoscopy. We excluded cases of advanced colorectal cancer. We retrospectively analyzed the CT colonography findings and follow-up conventional colonoscopy findings of 113 patients who had polyps more than 6 mm in diameter. Radiologists using 3D and 2D computer generated displays interpreted the CT colonography images. The colonoscopists were aware of the CT colonography findings before the procedure. CT colonography detected 132 polyps in 107 of the 113 patients and conventional colonoscopy detected 114 colorectal polyps more than 6 mm in diameter in 87 of the 113 patients. The sensitivity of CT colonography analyzed per polyp was 91% (41/45) for polyps more than 10 mm in diameter and 89% (101/114) for polyps more than 6 mm in diameter. Thirteen polyps were missed by CT colonography and were detected on follow-up conventional colonoscopy. CT colonography is a sensitive diagnostic tool for the detection of colorectal polyps and adequate bowel preparation, optimal bowel distention and clinical experience are needed to reduce the rate of missing appropriate lesions.

  14. In vivo microCT imaging of rodent cerebral vasculature

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Youngho; Hasegawa, Bruce H [Center for Molecular and Functional Imaging, Department of Radiology, University of California, San Francisco, CA 94143 (United States); Hashimoto, Tomoki; Nuki, Yoshitsugu [Center for Cerebrovascular Research, Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA 94143 (United States)], E-mail: youngho.seo@radiology.ucsf.edu

    2008-04-07

    arteries and major cerebral blood vessels were visible with contrast-enhanced CT, but not with noncontrast CT. In conclusion, the CT-compatible immobilization device was useful for in vivo microCT imaging of intracranial blood and of vascular structures within and immediately adjacent to the rodent brain. The microCT imaging technique is also compatible with continuous administration of a conventional iodinated contrast agent (e.g. iopromide) and therefore does not require specialized small animal specific contrast agent that has comparatively long in vivo residence time. (note)

  15. Comparative review of computed tomography of the spinal column and conventional x-ray films

    Energy Technology Data Exchange (ETDEWEB)

    Shin, H.; Yamaura, A.; Horie, T.; Makino, H. (Chiba Univ. (Japan). School of Medicine)

    1982-04-01

    Computerized tomography (CT) of the cervical spinal column was carried out in 39 patients using a GE.CT/T or Toshiba TCT60A scanner. There were 22 cervical disk lesions, 4 spinal neoplasms, 5 narrow spinal canals with or without ossification of the posterior longitudinal ligament, 2 syringomyelias, 5 traumas, and one Arnold-Chiari malformation. In all the patients, tomography was done after conventional spinal X-ray studies. The correlation between the CT findings and conventional X-ray films revealed the excellent capability of the CT. The measurement of the midline sagittal diameter of the spinal canal in the patient with the narrowest canal in this series showed 7.4 mm when done by CT and 9.6 mm when done by the conventional plain film at the C/sub 5/ level. To ascertain the precise sagittal diameter of the cord itself, CT myelography is indispensable after the intrathecal injection of metrizamide A; metrizamide CT myelogram is useful in determining the nature of the disease, the risk of and best approach to surgery, and the evaluation after a surgical procedure. Although the range of motion of cervical joints and intervertebral foramen are visible with the conventional films, the size of the spinal tumors, the degree of bony change, and the tumor extension to the paraspinal connective tissue can be precisely demonstrated only by CT. A CT study of the spine is a simple procedure and is less likely to produce complication, even with a metrizamide CT myelogram, though there are certain limitations in the examination.

  16. CT of pelvic fractures

    Energy Technology Data Exchange (ETDEWEB)

    Falchi, Marco E-mail: marcofalchi@yahoo.it; Rollandi, Gian Andrea

    2004-04-01

    Although magnetic resonance imaging has become the dominant modality for cross-sectional musculo-skeletal imaging, the widespread availability, speed, and versatility of computed tomography (CT) continue to make it a mainstay of emergency room (ER) diagnostic imaging. Pelvic ring and acetabular fractures occur as the result of significant trauma secondary to either a motor vehicle accident or a high-velocity fall. These injuries are correlated with significant morbidity and mortality, both from the complications of pelvic ring fractures and from commonly associated injuries. The most commonly used classification of pelvic and acetabular fractures has been based on conventional radiographs that are, in the majority of cases, sufficient to determine the type of injury. However, because of the complexity of pelvic and acetabular fractures, precise pathological anatomy is not easily demonstrated by routine radiographs and in many cases details of fractures are not visible. Moreover, the insufficient co-operation of the patient or the difficulty of maintaining special positions can be overcome by using computed tomography. Spiral computed tomography provides information regarding the extent of the fractures and is complementary to radiography for ascertaining the spatial arrangement of fracture fragments. Spiral computed tomography is an effective tool for understanding complex fracture patterns, particularly when combined with multi-planar reconstruction two-dimensional (MPR 2D) reformatted images or three-dimensional images (3D) images. Including these techniques of reconstruction in routine pelvic imaging protocols can change management in a significant number of cases. Subtle fractures, particularly those oriented in the axial plane, are better seen on MPR images or 3D volume-rendered images. Complex injuries can be better demonstrated with 3D volume-rendered images, and complicated spatial information about the relative positions of fracture fragments can be easily

  17. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body after a CT ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body after a CT ...

  19. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... for guiding minimally invasive procedures such as needle biopsies and needle aspirations of many areas of the ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body after ...

  1. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... for guiding minimally invasive procedures such as needle biopsies and needle aspirations of many areas of the ...

  2. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT scanning procedure. For exams (excluding head and neck) your head will remain outside the hole in ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: ...

  3. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... liver, shows up in shades of gray, and air appears black. With CT scanning, numerous x-ray ... injected into a vein) to help evaluate blood vessels and organs such as the liver, kidneys and ...

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... is painless, noninvasive and accurate. It’s also the most reliable imaging technique for determining if the sinuses ... CT scan of the sinuses, the patient is most commonly positioned lying flat on the back. The ...

  5. CT Angiography (CTA)

    Science.gov (United States)

    ... during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and ... of the procedure, you may be asked to complete a questionnaire to ensure your safety during this ...

  6. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... visibility of certain tissues or blood vessels. A nurse or technologist will insert an intravenous (IV) line ... CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ...

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  9. Pediatric CT Scans

    Science.gov (United States)

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

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  13. Computed Tomography (CT) -- Head

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    ... an image on a special electronic image recording plate. Bones appear white on the x-ray; soft ... which are then displayed on a monitor. CT imaging is sometimes compared to looking into a loaf ...

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  15. Abdominal and Pelvic CT

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    ... an image on a special electronic image recording plate. Bones appear white on the x-ray; soft ... which are then displayed on a monitor. CT imaging is sometimes compared to looking into a loaf ...

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  14. CT head in children

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Padma, E-mail: padma.rao@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia); Bekhit, Elhamy, E-mail: elhamy.bekhit@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia); Ramanauskas, Fiona, E-mail: fiona.ramanauskas@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia); Kumbla, Surekha, E-mail: surekha.kumbla@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia)

    2013-07-15

    The advances in computerized technology (CT) technique over the last few decades have greatly modified imaging protocols in children. The range of pathologies that can now be demonstrated has broadened with the advent of newer techniques such as CT perfusion and the ability to perform complex reconstructions. Increasing speed of scanning and reduction in scan time have influenced the need for sedation and general anaesthetic as well as impacting on motion artefact. Additionally, concerns about radiation safety and avoidance of unnecessary radiation have further impacted on the inclusion of CT in the imaging armamentarium. Justification and image optimisation are essential. It is important to familiarize oneself with the appearances of normal variants or age related developmental changes. CT does however remain an appropriate investigation in a number of conditions.

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... modality for sinusitis. CT of the sinuses is now widely available and is performed in a relatively short time, especially when compared to magnetic resonance imaging (MRI). ...

  16. Lumbosacral spine CT

    Science.gov (United States)

    ... More Broken bone CT scan Cyst Herniated disk Osteoarthritis Osteomalacia Tumor Review Date 9/8/2014 Updated by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, ...

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  19. Computed Tomography (CT) -- Sinuses

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  1. Abdominal and Pelvic CT

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    Full Text Available ... of electronic x-ray detectors rotate around you, measuring the amount of radiation being absorbed throughout your ... pancreas. When you enter the CT scanner, special light lines may be seen projected onto your body, ...

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  4. Abdominal and Pelvic CT

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  15. Abdominal and Pelvic CT

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    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological ...

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  18. Abdominal and Pelvic CT

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    Full Text Available ... painless, noninvasive and accurate. In emergency cases, it can reveal internal injuries and bleeding quickly enough to ... cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... therapy for brain cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to ... cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even ...

  20. Chest CT Scan

    Science.gov (United States)

    ... can combine these pictures to create three-dimensional (3D) models to help show the size, shape, and ... a medical imaging facility or hospital. The CT scanner is a large, tunnel-like machine that has ...

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, medications you’re taking, and allergies. You ... a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple ...

  2. Abdominal and Pelvic CT

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  3. Computed Tomography (CT) -- Head

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    Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, medications you’re taking, and allergies. You ... a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple ...

  4. Abdominal and Pelvic CT

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    Full Text Available ... scanning is fast, painless, noninvasive and accurate. In emergency cases, it can reveal internal injuries and bleeding ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ...

  5. Computed Tomography (CT) -- Head

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    Full Text Available ... to plan radiation therapy for brain cancer. In emergency cases, it can reveal internal injuries and bleeding ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed information on head ...

  7. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. A CT scan of the face produces images ...

  8. Abdominal and Pelvic CT

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    Full Text Available ... CT) of the abdomen and pelvis is a diagnostic imaging test used to help detect diseases of the ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ...

  9. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... of the nasal cavity and sinuses. plan for surgery by defining anatomy. top of page How should ... CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a ...

  10. Abdominal and Pelvic CT

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  11. Abdominal and Pelvic CT

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    Full Text Available ... as: infections such as appendicitis , pyelonephritis or infected fluid collections, also known as abscesses. inflammatory bowel disease ... caused by a burst appendix or an infected fluid collection and the subsequent spread of infection. CT ...

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    Full Text Available ... cavity. CT scanning is painless, noninvasive and accurate. It’s also the most reliable imaging technique for determining ... parts absorb the x-rays in varying degrees. It is this crucial difference in absorption that allows ...

  13. Lumbar spine CT scan

    Science.gov (United States)

    CAT scan - lumbar spine; Computed axial tomography scan - lumbar spine; Computed tomography scan - lumbar spine; CT - lower back ... your breath for short periods of time. The scan should take only 10 to 15 minutes.

  14. Abdominal and Pelvic CT

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    Full Text Available ... Abdomen and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed tomography, more commonly known as ... of page What are some common uses of the procedure? This procedure is typically used to help ...

  15. Abdominal and Pelvic CT

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    Full Text Available ... entire body will be "inside" the scanner at one time such as with MRI. If an intravenous ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  16. Cervical spine CT scan

    Science.gov (United States)

    ... defects of the cervical spine Bone problems Fracture Osteoarthritis Disc herniation Risks Risks of CT scans include: ... Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, ...

  17. CT of pituitary abscess

    Energy Technology Data Exchange (ETDEWEB)

    Fong, T.C.; Johns, R.D.; Long, M.; Myles, S.T.

    1985-06-01

    Pituitary abscess is a rare condition, with only 50 cases reported in the literature. Of those, 29 cases were well documented for analysis. Preoperative diagnosis of pituitary abscess is difficult. The computed tomographic (CT) appearance of pituitary abscess was first described in 1983; the abscess was depicted by axial images with coronal reconstruction. The authors recently encountered a case of pituitary abscess documented by direct coronal CT of the sella turcica.

  18. Metal-related artifacts in instrumented spine. Techniques for reducing artifacts in CT and MRI: state of the art

    OpenAIRE

    Stradiotti, P.; Curti, A.; G. Castellazzi; Zerbi, A.

    2009-01-01

    The projectional nature of radiogram limits its amount of information about the instrumented spine. MRI and CT imaging can be more helpful, using cross-sectional view. However, the presence of metal-related artifacts at both conventional CT and MRI imaging can obscure relevant anatomy and disease. We reviewed the literature about overcoming artifacts from metallic orthopaedic implants at high-field strength MRI imaging and multi-detector CT. The evolution of multichannel CT has made available...

  19. Biodiesel from conventional feedstocks.

    Science.gov (United States)

    Du, Wei; Liu, De-Hua

    2012-01-01

    At present, traditional fossil fuels are used predominantly in China, presenting the country with challenges that include sustainable energy supply, energy efficiency improvement, and reduction of greenhouse gas emissions. In 2007, China issued The Strategic Plan of the Mid-and-Long Term Development of Renewable Energy, which aims to increase the share of clean energy in the country's energy consumption to 15% by 2020 from only 7.5% in 2005. Biodiesel, an important renewable fuel with significant advantages over fossil diesel, has attracted great attention in the USA and European countries. However, biodiesel is still in its infancy in China, although its future is promising. This chapter reviews biodiesel production from conventional feedstocks in the country, including feedstock supply and state of the art technologies for the transesterification reaction through which biodiesel is made, particularly the enzymatic catalytic process developed by Chinese scientists. Finally, the constraints and perspectives for China's biodiesel development are highlighted.

  20. Diverticular disease in CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Lefere, P.; Gryspeerdt, S.; Baekelandt, M.; Holsbeeck, B. van [Dept. of Radiology, Roeselare (Belgium); Dewyspelaere, J. [Dept. of Gastroenterology, Roeselare (Belgium)

    2003-12-01

    The aim of this study was to evaluate findings on CT colonography (CTC) in patients with diverticular disease. In a retrospective analysis of 160 consecutive patients, who underwent CTC and conventional colonoscopy (CC), patients with diverticular disease were retrieved. The CTC images were compared with CC and, if possible, with pathology. Findings on both 2D and 3D images are illustrated with emphasis on diagnostic problems and the possible solutions to overcome these problems. Several aspects of diverticulosis were detected: prediverticulosis (3%); global (55.6%); and focal wall thickening (4%) caused by thickened haustral folds, fibrosis, inflammation and adenocarcinoma; diverticula (52%); pseudopolypoid lesions caused by diverticular fecaliths (39%); inverted diverticula (1.2%); and mucosal prolapse (0.6%). Solutions to overcome pitfalls are described as abdominal windowing, content of the pseudopolypoid lesion, comparison of 2D and 3D images, prone-supine imaging and the aspect of the pericolic fat. In this series there were equivocal findings in case of mucosal prolapse (0.6%) and focal wall thickening (4%). Diverticulosis is a challenge for CTC to avoid false-positive diagnosis of polypoid and tumoral disease. Knowledge of possible false causes of polypoid disease and comparison of 2D and 3D images are necessary to avoid false-positive diagnosis. In case of equivocal findings additional conventional colonoscopy should be advised whenever a clinically significant lesion ({>=}1 cm) is suspected. (orig.)

  1. What constitutes a convention? : implications for the coexistence of conventions

    OpenAIRE

    Kolstad, Ivar

    2002-01-01

    A model of repeated play of a coordination game, where stage games have a location in social space, and players receive noisy signals of the true location of their games, is reviewed. Sugden (1995) suggests that in such a model, there can be a stationary state of convention coexistence only if interaction is non-uniform across social space. This paper shows that an alternative definition of conventions, which links conventions to actions rather than expectations, permits convention coexistenc...

  2. The role of CT in the diagnosis of sacro-iliitis

    Energy Technology Data Exchange (ETDEWEB)

    Geijer, M.; Sihlbom, H.; Goethlin, J.H. [Goeteborg Univ., Dept. of Diagnostic Radiology (Sweden); Nordborg, E. [Goeteborg Univ., Dept. of Rheumatology (Sweden)

    1998-05-01

    Objective: Ankylosing spondylitis is a progressive, debilitating disease in which early diagnosis and early treatment can improve the prognosis. Radiographic confirmation is essential for diagnosis but conventional radiogrpahy has not proved useful, particularly in the early course of the disease. The aims of this study were to correlate the findings at conventional radiography with those at CT, and to correlate the duration of clinical symptoms with the radiological findings. Material and Methods: Forty patients with clinical sacro-iliitis and 13 controls were evaluated by means of conventional radiography and CT. Results: Conventional radiography was positive in 10/40 patients and CT in 30/40 patients. Conventional radiography was positive in only 2/14 patients with a symptom duration of less than 2 years while CT was positive in 10/14 such patients. Conclusion: The study demonstrated a considerably higher sensitivity in CT than in conventional radiography in detecting the subtle changes necessary for the radiological diagnosis of sacro-iliitis, particularly in cases of short duration. CT allows an early start to be made in treatment with a consequently improved prognosis. The use of conventional radiography cannot be recommended because its low sensitivity delays diagnosis in many instances. (orig.).

  3. Estimation of radiation cancer risk in CT-KUB

    Science.gov (United States)

    Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Bradley, D. A.; Ang, W. C.; Bahrudin, N. A.; Mhareb, M. H. A.

    2017-08-01

    The increased demand for computed tomography (CT) in radiological scanning examinations raises the question of a potential health impact from the associated radiation exposures. Focusing on CT kidney-ureter-bladder (CT-KUB) procedures, this work was aimed at determining organ equivalent dose using a commercial CT dose calculator and providing an estimate of cancer risks. The study, which included 64 patients (32 males and 32 females, mean age 55.5 years and age range 30-80 years), involved use of a calibrated CT scanner (Siemens-Somatom Emotion 16-slice). The CT exposures parameter including tube potential, pitch factor, tube current, volume CT dose index (CTDIvol) and dose-length product (DLP) were recorded and analyzed using CT-EXPO (Version 2.3.1, Germany). Patient organ doses, including for stomach, liver, colon, bladder, red bone marrow, prostate and ovaries were calculated and converted into cancer risks using age- and sex-specific data published in the Biological Effects of Ionizing Radiation (BEIR) VII report. With a median value scan range of 36.1 cm, the CTDIvol, DLP, and effective dose were found to be 10.7 mGy, 390.3 mGy cm and 6.2 mSv, respectively. The mean cancer risks for males and females were estimated to be respectively 25 and 46 out of 100,000 procedures with effective doses between 4.2 mSv and 10.1 mSv. Given the increased cancer risks from current CT-KUB procedures compared to conventional examinations, we propose that the low dose protocols for unenhanced CT procedures be taken into consideration before establishing imaging protocols for CT-KUB.

  4. Calibration free beam hardening correction for cardiac CT perfusion imaging

    Science.gov (United States)

    Levi, Jacob; Fahmi, Rachid; Eck, Brendan L.; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    Myocardial perfusion imaging using CT (MPI-CT) and coronary CTA have the potential to make CT an ideal noninvasive gate-keeper for invasive coronary angiography. However, beam hardening artifacts (BHA) prevent accurate blood flow calculation in MPI-CT. BH Correction (BHC) methods require either energy-sensitive CT, not widely available, or typically a calibration-based method. We developed a calibration-free, automatic BHC (ABHC) method suitable for MPI-CT. The algorithm works with any BHC method and iteratively determines model parameters using proposed BHA-specific cost function. In this work, we use the polynomial BHC extended to three materials. The image is segmented into soft tissue, bone, and iodine images, based on mean HU and temporal enhancement. Forward projections of bone and iodine images are obtained, and in each iteration polynomial correction is applied. Corrections are then back projected and combined to obtain the current iteration's BHC image. This process is iterated until cost is minimized. We evaluate the algorithm on simulated and physical phantom images and on preclinical MPI-CT data. The scans were obtained on a prototype spectral detector CT (SDCT) scanner (Philips Healthcare). Mono-energetic reconstructed images were used as the reference. In the simulated phantom, BH streak artifacts were reduced from 12+/-2HU to 1+/-1HU and cupping was reduced by 81%. Similarly, in physical phantom, BH streak artifacts were reduced from 48+/-6HU to 1+/-5HU and cupping was reduced by 86%. In preclinical MPI-CT images, BHA was reduced from 28+/-6 HU to less than 4+/-4HU at peak enhancement. Results suggest that the algorithm can be used to reduce BHA in conventional CT and improve MPI-CT accuracy.

  5. Comparison of Surface Water Quality and Yields from Organically and Conventionally Produced Sweet Corn Plots with Conservation and Conventional Tillage.

    Science.gov (United States)

    Edgell, Joshua; Osmond, D L; Line, D E; Hoyt, G D; Grossman, J M; Larsen, E M

    2015-11-01

    Organic agricultural systems are often assumed to be more sustainable than conventional farming, yet there has been little work comparing surface water quality from organic and conventional production, especially under the same cropping sequence. Our objective was to compare nutrient and sediment losses, as well as sweet corn ( L. var. ) yield, from organic and conventional production with conventional and conservation tillage. The experiment was located in the Appalachian Mountains of North Carolina. Four treatments, replicated four times, had been in place for over 18 yr and consisted of conventional tillage (chisel plow and disk) with conventional production (CT/Conven), conservation no-till with conventional production (NT/Conven), conventional tillage with organic production (CT/Org), and conservation no-till with organic production (NT/Org). Water quality (surface flow volume; nitrogen, phosphorus, and sediment concentrations) and sweet corn yield data were collected in 2011 and 2012. Sediment and sediment-attached nutrient losses were influenced by tillage and cropping system in 2011, due to higher rainfall, and tillage in 2012. Soluble nutrients were affected by the nutrient source and rate, which are a function of the cropping system. Sweet corn marketable yields were greater in conventional systems due to high weed competition and reduced total nitrogen availability in organic treatments. When comparing treatment efficiency (yield kg ha /nutrient loss kg ha ), the NT/Conven treatment had the greatest sweet corn yield per unit of nutrient and sediment loss. Other treatment ratios were similar to each other; thus, it appears the most sustainably productive treatment was NT/Conven.

  6. High resolution CT of temporal bone trauma

    Energy Technology Data Exchange (ETDEWEB)

    Youn, Eun Kyung [Korea General Hospital, Seoul (Korea, Republic of)

    1986-10-15

    Radiographic studies of the temporal bone following head trauma are indicated when there is cerebrospinal fluid otorrhea or rhinorrhoea, hearing loss, or facial nerve paralysis. Plain radiography displays only 17-30% of temporal bone fractures and pluridirectional tomography is both difficult to perform, particularly in the acutely ill patient, and less satisfactory for the demonstration of fine fractures. Consequently, high resolution CT is the imaging method of choice for the investigation of suspected temporal bone trauma and allows special resolution of fine bony detail comparable to that attainable by conventional tomography. Eight cases of temporal bone trauma examined at Korea General Hospital April 1985 through May 1986. The results were as follows: Seven patients (87%) suffered longitudinal fractures. In 6 patients who had purely conductive hearing loss, CT revealed various ossicular chain abnormality. In one patient who had neuro sensory hearing loss, CT demonstrated intract ossicular with a fracture nearing lateral wall of the lateral semicircular canal. In one patient who had mixed hearing loss, CT showed complex fracture.

  7. Convention Theory in the Anglophone Agro-food Literature

    DEFF Research Database (Denmark)

    Ponte, Stefano

    2016-01-01

    In the past two decades, convention theory has been applied in various branches of agro-food studies, providing analytical and theoretical insight for examining alternative food networks, coordination and governance in agro-food value chains, and the so-called 'quality turn' in food production...... and consumption. In this article, I examine convention theory applications in the Anglophone literature on agro-food studies through the review of 51 relevant contributions. I highlight how CT has helped explain different modes of organization and coordination of agro-food operations in different places, and how...

  8. Conventional mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Tobias Joseph

    2010-01-01

    Full Text Available The provision of mechanical ventilation for the support of infants and children with respiratory failure or insufficiency is one of the most common techniques that are performed in the Pediatric Intensive Care Unit (PICU. Despite its widespread application in the PICUs of the 21st century, before the 1930s, respiratory failure was uniformly fatal due to the lack of equipment and techniques for airway management and ventilatory support. The operating rooms of the 1950s and 1960s provided the arena for the development of the manual skills and the refinement of the equipment needed for airway management, which subsequently led to the more widespread use of endotracheal intubation thereby ushering in the era of positive pressure ventilation. Although there seems to be an ever increasing complexity in the techniques of mechanical ventilation, its successful use in the PICU should be guided by the basic principles of gas exchange and the physiology of respiratory function. With an understanding of these key concepts and the use of basic concepts of mechanical ventilation, this technique can be successfully applied in both the PICU and the operating room. This article reviews the basic physiology of gas exchange, principles of pulmonary physiology, and the concepts of mechanical ventilation to provide an overview of the knowledge required for the provision of conventional mechanical ventilation in various clinical arenas.

  9. PET-CT; PET-CT

    Energy Technology Data Exchange (ETDEWEB)

    Schober, O. [Univeritaetsklinikum Muenster (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Heindel, W. [Univeritaetsklinikum Muenster (Germany). Inst. fuer Klinische Radiologie

    2008-07-01

    Positron emission tomography - computerized tomography (PET-CT) is the fusion of two modern imaging techniques. The book includes the following chapters: 1. fundamentals: radiation protection aspects, radionuclide production, contrast agents, patient preparation, image interpretation; 2. diagnostics of carcinomas: carcinomas in brain, head-throat, thyroid, lungs, intestinal tract, gynecological carcinomas, urinary tract and bladder carcinomas, prostate carcinomas, malignant lymphomas, malignant malinomas, carcinomas in the skeletal system; 3. infections; 4. diagnostics of cardiovascular diseases; 5. diagnostics of neurodegenerative diseases; 6. developments and perspectives, 7. attachments: internet links, glossary, abbreviations.

  10. CT enterography: Principles, technique and utility in Crohn's disease

    Energy Technology Data Exchange (ETDEWEB)

    Huprich, James E. [Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 (United States)], E-mail: huprich@mayo.edu; Fletcher, J.G. [Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 (United States)], E-mail: fletcher.joel@mayo.edu

    2009-03-15

    CT enterography is a modification of conventional CT technique optimized for the evaluation of small bowel. This technique utilizes multidetector scanners with high spatial and temporal resolution; multiplanar reconstructions; and large volumes of enteric contrast to provide bowel distension. This article discusses the essential principles of the exam and its use in the evaluation of Crohn's disease of the small bowel.

  11. Utility of 18FDG-PET/CT in breast cancer diagnostics--a systematic review

    DEFF Research Database (Denmark)

    Warning, Karina; Hildebrandt, Malene Grubbe; Kristensen, Bent

    2011-01-01

    as a primary diagnostic procedure in breast cancer; but it has the potential to be useful for the detection of distant metastases and for monitoring response to chemotherapy in breast cancer patients. PET/CT should still be regarded as a supplement to conventional diagnostic procedures such as CT and MRI....

  12. ESD and the Rio Conventions

    Science.gov (United States)

    Sarabhai, Kartikeya V.; Ravindranath, Shailaja; Schwarz, Rixa; Vyas, Purvi

    2012-01-01

    Chapter 36 of Agenda 21, a key document of the 1992 Earth Summit, emphasised reorienting education towards sustainable development. While two of the Rio conventions, the Convention on Biological Diversity (CBD) and the United Nations Framework Convention on Climate Change (UNFCCC), developed communication, education and public awareness (CEPA)…

  13. CT images of gossypiboma

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Hae Jeong; Lim, Jong Nam; Choi, Young Chil; Park, Jeong Hee [College of Medicine, Kon-Kuk University, Seoul (Korea, Republic of)

    1994-04-15

    Surgical sponges retained after laparotomy can cause serious problem if they were not be identified in early state. In these circumstances abdominal CT yields the accurate diagnostic images. The purpose of this report is to present highly indicative findings permitting correct preoperative diagnosis of the gossypiboma. We experienced three cases in which CT showed the images sufficiently characteristic to suggest the correct preoperative diagnosis. We evaluated retrospectively the radiological images of gossypiboma confirmed by operation. Three patients were admitted due to palpable masses. Two female patients had medical histories of cesarean sections and a male patient had been operated due to malignant fibrous histiocytoma, previously. Abdominal CT scan of one case revealed huge ovoid hypodense mass with enhanced peripheral rim. Calcific spots and whirl-like stripes were noted within the lesion. Towel was found in pathologic specimen. CT images of two patients showed well-encapsulated, mixed fluid and soft tissue density mass with several gas bubbles. Surgical sponges were found within abscesses. The authors conclude that these characteristic CT findings and careful histories of surgery are very useful for correct pre-operative diagnosis and permit the guideline for the optimal plan of the surgical treatment.

  14. CT findings of fibromatoses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hak Nam; Choi, Yeon Hwa; Shin, Hyun Jun [Lee Rha Hospital, Chung Ju (Korea, Republic of)

    1991-03-15

    Fibromatoses constitute a group of benign fibroblastic soft tissue tumors with a tendency for local invasion and recurrence. CT provides excellent anatomic detail of soft tissue tumors and precise location, size, and extent of the tumors. The authors evaluated 7 CT scans of 6 pathologically proven aggressive fibromatoses during the last 4 years. Five lesions arose in the lower extremities: 4 in the buttocks and 1 in the thigh. One lesion arose in the upper back. The tumors were lobulated in contour and varied in size from 3.7 cm to 10.7 cm. Fibromatosis tumors were usually hypodense with muscle when no contrast medium was used and hyperdense with better delineation during infusion of the contrast medium. Three patients had recurrent disease after surgical removal. Fibromatosis may infiltrate the surrounding tissue beyond the margins, indicated on CT scans and by palpation at operation. Therefore the surgeon should plan a wide resection around the apparent limits of the fibromatosis.

  15. The additional value of CT images interpretation in the differential diagnosis of benign vs. malignant primary bone lesions with 18F-FDG-PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, K.; Stumpe, K.D.M.; Hany, T.F.; Mende, K.; Veit-Haibach, P.; Schulthess, G.K. von [University Hospital Zurich, Division of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); Exner, U.E. [University Hospital Balgrist, Department of Orthopedic Surgery, Zurich (Switzerland); Bode, B. [University Hospital Zurich, Institute of Surgical Pathology, Zurich (Switzerland); Hodler, Juerg [University Hospital Balgrist, Department of Radiology, Zurich (Switzerland)

    2008-11-15

    To evaluate the value of a dedicated interpretation of the CT images in the differential diagnosis of benign vs. malignant primary bone lesions with 18fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT). In 50 consecutive patients (21 women, 29 men, mean age 36.9, age range 11-72) with suspected primary bone neoplasm conventional radiographs and 18F-FDG-PET/CT were performed. Differentiation of benign and malignant lesions was separately performed on conventional radiographs, PET alone (PET), and PET/CT with specific evaluation of the CT part. Histology served as the standard of reference in 46 cases, clinical, and imaging follow-up in four cases. According to the standard of reference, conventional 17 lesions were benign and 33 malignant. Sensitivity, specificity, and accuracy in assessment of malignancy was 85%, 65% and 78% for conventional radiographs, 85%, 35% and 68% for PET alone and 91%, 77% and 86% for combined PET/CT. Median SUV{sub max} was 3.5 for benign lesions (range 1.6-8.0) and 5.7 (range 0.8-41.7) for malignant lesions. In eight patients with bone lesions with high FDG-uptake (SUV{sub max} {>=} 2.5) dedicated CT interpretation led to the correct diagnosis of a benign lesion (three fibrous dysplasias, two osteomyelitis, one aneurysmatic bone cyst, one fibrous cortical defect, 1 phosphaturic mesenchymal tumor). In four patients with lesions with low FDG-uptake (SUV{sub max} < 2.5) dedicated CT interpretation led to the correct diagnosis of a malignant lesion (three chondrosarcomas and one leiomyosarcoma). Combined PET/CT was significantly more accurate in the differentiation of benign and malignant lesions than PET alone (p =.039). There was no significant difference between PET/CT and conventional radiographs (p =.625). Dedicated interpretation of the CT part significantly improved the performance of FDG-PET/CT in differentiation of benign and malignant primary bone lesions compared to PET alone. PET/CT more commonly

  16. Imaging lobular breast carcinoma: comparison of synchrotron radiation DEI-CT technique with clinical CT, mammography and histology

    Science.gov (United States)

    Fiedler, S.; Bravin, A.; Keyriläinen, J.; Fernández, M.; Suortti, P.; Thomlinson, W.; Tenhunen, M.; Virkkunen, P.; Karjalainen-Lindsberg, M.-L.

    2004-01-01

    Different modalities for imaging cancer-bearing breast tissue samples are described and compared. The images include clinical mammograms and computed tomography (CT) images, CT images with partly coherent synchrotron radiation (SR), and CT and radiography images taken with SR using the diffraction enhanced imaging (DEI) method. The images are evaluated by a radiologist and compared with histopathological examination of the samples. Two cases of lobular carcinoma are studied in detail. The indications of cancer are very weak or invisible in the conventional images, but the morphological changes due to invasion of cancer become pronounced in the images taken by the DEI method. The strands penetrating adipose tissue are seen clearly in the DEI-CT images, and the histopathology confirms that some strands contain the so-called 'Indian file' formations of cancer cells. The radiation dose is carefully measured for each of the imaging modalities. The mean glandular dose (MGD) for 50% glandular breast tissue is about 1 mGy in conventional mammography and less than 0.25 mGy in projection DEI, while in the clinical CT imaging the MGD is very high, about 45 mGy. The entrance dose of 95 mGy in DEI-CT imaging gives rise to an MGD of 40 mGy, but the dose may be reduced by an order of magnitude, because the contrast is very large in most images.

  17. CT angiography by means of intra-arterial contrast infusion

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Junichiro; Watanabe, Hiroshi; Shiogai, Toshiyuki; Konishi, Yoshifumi; Hara, Mitsuhiro (Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine)

    1983-10-01

    CT angiography (CT-AG) by means of intra-arterial contrast infusion was carried out, and its clinical usefulness was evaluated in various intracranial lesions. The practical and diagnostic merits of CT-AG are as follows: a selective enhancement of the cerebral vessels by an extremely small amount of the contrast substance, accompanied by a satisfactory resolution of fine arterioles and arteries. The excellent ability of the CT to detect differences in the X-ray absorption coefficients surpasses that of cerebral angiography. An intracranial aneurysm which was not visualized by the angiography appeared between arterial branches upon CT-AG. The three-dimensional configuration of the aneurysmal body and its related artery, the pointing direction of the aneurysm, and the angle between the aneurysmal axis and the afferent artery were clearly shown. The fine structure of arteriovenous malformation could be shown concurrently with the cerebral tissue and the ventricle. The axial view of the circle of Willis gives important information for surgical intervention. Concerning brain tumors, the structural correlation between the tumor and the cerebral arteries became apparent when the CT-AG was carried out immediately after a conventional contrast-enhancement. Such a ''double contrast'' allows safe surgical access to the intracranial tumor. CT-AG in the case of ''Moyamoya'' disease visualized fine moyamoya vessels extending all over the cerebral hemisphere; those vessels were less prominent in the ordinary angiograms. The vascular networks of the arteriovenous malformation, which were not evident in the ordinary angiograms, were also revealed by the CT-AG. For the patient with poor prospects, CT-AG will be were valid as a screening study than ordinary angiography because of its less invasive procedure using a small amount of the contrast substance. CT-AG on a dynamic scan mode possible optimal timing in the visualization of the

  18. [Post-mortem angio-CT: a new diagnostic approach].

    Science.gov (United States)

    Grabherr, S; Dominguez, A; Mangin, P

    2011-07-27

    Post-mortem CT-angiography is a minimally invasive exam that allows the investigation of the vascular system in a very detailed way, impossible to realize during conventional autopsy. The research group for post-mortem angio-CT in Lausanne has developed a standardized protocol fora technique called "multi-phase post-mortem CT-angiography" that leads to an easy applicable performance of the exam and an increased diagnostic value. Additionally, new equipment including a perfusion device with single use sets as well as a special contrast agent for post-mortem investigations has been created. Using this technique, angio-CT permits to detect of the source of haemorrhages, vascular malformations, arteriosclerotic lesions as well as vascular occlusions and to visualize the vascular anatomy exactly.

  19. Flat-panel volume CT: fundamental principles, technology, and applications.

    Science.gov (United States)

    Gupta, Rajiv; Cheung, Arnold C; Bartling, Soenke H; Lisauskas, Jennifer; Grasruck, Michael; Leidecker, Christianne; Schmidt, Bernhard; Flohr, Thomas; Brady, Thomas J

    2008-01-01

    Flat-panel volume computed tomography (CT) systems have an innovative design that allows coverage of a large volume per rotation, fluoroscopic and dynamic imaging, and high spatial resolution that permits visualization of complex human anatomy such as fine temporal bone structures and trabecular bone architecture. In simple terms, flat-panel volume CT scanners can be thought of as conventional multidetector CT scanners in which the detector rows have been replaced by an area detector. The flat-panel detector has wide z-axis coverage that enables imaging of entire organs in one axial acquisition. Its fluoroscopic and angiographic capabilities are useful for intraoperative and vascular applications. Furthermore, the high-volume coverage and continuous rotation of the detector may enable depiction of dynamic processes such as coronary blood flow and whole-brain perfusion. Other applications in which flat-panel volume CT may play a role include small-animal imaging, nondestructive testing in animal survival surgeries, and tissue-engineering experiments. Such versatility has led some to predict that flat-panel volume CT will gain importance in interventional and intraoperative applications, especially in specialties such as cardiac imaging, interventional neuroradiology, orthopedics, and otolaryngology. However, the contrast resolution of flat-panel volume CT is slightly inferior to that of multidetector CT, a higher radiation dose is needed to achieve a comparable signal-to-noise ratio, and a slower scintillator results in a longer scanning time.

  20. The need for skull radiography in patients presenting for CT

    Energy Technology Data Exchange (ETDEWEB)

    Tress, B.M.

    1983-01-01

    One thousand patients had both CT of the head and a conventional skull series of radiographs. Radiographic findings were abnormal in 250 patients (25%), but only 64 patients (6.4%) had diagnostically significant abnormalities at radiography that were not detected by CT. If the 163 patients who presented after acute trauma were excluded from the series, only 39 (4.7%) of the remaining patients had radiographically significant abnormal findings that were not seen at CT, and only two (0.2%) of these abnormalities could not be diagnosed by a lateral skull radiograph alone. In only five patients (0.5%) was the management actively changed because an abnormaltiy that was detected at skull radiography was not detected at CT. Thus, in nontrauma patients who have stroke, epilepsy, dementia, or non-specific symptoms without focal signs, or have recently undergone craniotomy, and who have been referred for CT, skull radiographs are not justified. In the patient with a history and findings that are strongly suggestive of a pathological disorder anywhere other than in the sella turcica, cerebello-pontine angle, and paranasal sinuses, only the lateral skull radiograph should be obtained after CT, and only if CT is equivocal.

  1. PET/CT imaging in lung cancer: indications and findings

    Directory of Open Access Journals (Sweden)

    Bruno Hochhegger

    2015-06-01

    Full Text Available The use of PET/CT imaging in the work-up and management of patients with lung cancer has greatly increased in recent decades. The ability to combine functional and anatomical information has equipped PET/CT to look into various aspects of lung cancer, allowing more precise disease staging and providing useful data during the characterization of indeterminate pulmonary nodules. In addition, the accuracy of PET/CT has been shown to be greater than is that of conventional modalities in some scenarios, making PET/CT a valuable noninvasive method for the investigation of lung cancer. However, the interpretation of PET/CT findings presents numerous pitfalls and potential confounders. Therefore, it is imperative for pulmonologists and radiologists to familiarize themselves with the most relevant indications for and limitations of PET/CT, seeking to protect their patients from unnecessary radiation exposure and inappropriate treatment. This review article aimed to summarize the basic principles, indications, cancer staging considerations, and future applications related to the use of PET/CT in lung cancer.

  2. Clinical micro-CT for dental imaging

    Science.gov (United States)

    Youn, Hanbean; Cho, Min Kook; Shon, Cheol-Soon; Cho, Bong Hae; Kim, Chang Hyuk; Kim, Ho Kyung

    2009-02-01

    We exploit the development of a clinical computed microtomography (micro-CT) system for dental imaging. While the conventional dental CT simply serves implant treatment, the clinical dental micro-CT may provide clinicians with a histologic evaluation. To investigate the feasibility of the realization of a dental micro-CT, we have constructed an experimental test system which mainly consists of a microfocus x-ray source, a rotational subject holder, and a flat-panel detector. The flat-panel detector is based on a matrix-addressed photodiode array coupled to a CsI:Tl scintillator. The detective quantum efficiency (DQE) of the detector was measured as a function of magnification based on the measured modulation-transfer function (MTF) and noise-power spectrum (NPS). The best MTF and DQE performances were achieved at the magnification factor of 3. Similar tendency of the spatial resolving power in tomography was also observed with a wire phantom having a 25 μm diameter. From the investigation of tomographs reconstructed from a humanoid skull phantom, the application of magnification in the system largely reduced both signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for a fixed dose at the entrance surface of the detector, 1.2 mGy, while this setup increased the dose at the object plane from 4.7 mGy to 19.1 mGy for the magnification factor from 2 to 4, respectively. Although the quantum mottles at the high magnification factor tackled the practical use in the clinic, the information contained in the magnified CT images was quite promising.

  3. Cardiac CT angiography after coronary artery surgery in children using 64-slice CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Marini, Davide; Agnoletti, Gabriella [Centre de Reference Malformations Cardiaques Congenitales Complexes-M3C, Universite Paris Descartes, UFR Necker-Enfants Malades, Paris (France); Brunelle, Francis [University Paris Descartes, UFR Necker-Enfants Malades, Department of Pediatric Radiology, APHP, Paris (France); Sidi, Daniel; Bonnet, Damien [Centre de Reference Malformations Cardiaques Congenitales Complexes-M3C, Universite Paris Descartes, UFR Necker-Enfants Malades, Paris (France); Ou, Phalla [Centre de Reference Malformations Cardiaques Congenitales Complexes-M3C, Universite Paris Descartes, UFR Necker-Enfants Malades, Paris (France); University Paris Descartes, UFR Necker-Enfants Malades, Department of Pediatric Radiology, APHP, Paris (France)], E-mail: phalla.ou@nck.aphp.fr

    2009-09-15

    Objective: The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of graft and/or coronary angioplasty stenosis in children who had undergone coronary artery surgery. Population and methods: Fifteen consecutive children (8 male and 7 female; age 9.2 {+-} 6.1 years) underwent 64-slice CT because of chest pain or ECG changes mean 4.8 {+-} 3.7 years after surgical coronary artery surgery; 10 patients had coronary angioplasty using a patch from the saphenous vein, four had mammary artery bypass, and one had saphenous vein bypass. Six main segments of the coronary arteries and all the bypass graft considered as a single segment were analyzed and compared with invasive angiography used as the reference standard. Results: CT correctly identified the four children with coronary angioplasty and mammary graft lesions that were confirmed by conventional angiography: one patient had a significant stenosis (>50% stenosis) at the mammary bypass graft anastomosis site; three other had non-significant stenosis (<50% stenosis) including a mild lesion of the saphenous vein patch in two patients and a mild lesion at the anastomosis site of the mammary bypass in one. All segments identified as normal by CT in the other 11 children were also found to be normal by conventional angiography. Conclusion: In centers expert in this technique, 64-slice CT scanning is a promising, rapid, and useful diagnostic technique for evaluating both coronary angioplasty and bypass graft lesions in children who had undergone coronary artery surge0008.

  4. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... liver, kidney, pancreatic, uterine or ovarian abnormalities, the evaluation and diagnosis with MRI may be preferable over CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal ...

  5. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... x-rays, particularly of soft tissues and blood vessels. A CT scan of the face produces images that also show a patient's paranasal sinus cavities. The paranasal sinuses are hollow, air-filled spaces located within the bones of the ...

  6. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... The teddy bear denotes child-specific content. Related Articles and Media Ultrasound - Abdomen X-ray (Radiography) - Lower GI Tract X-ray (Radiography) - Upper GI Tract Colorectal Cancer Images related to Computed Tomography (CT) - Abdomen and ...

  7. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... and Resources RTAnswers.org: Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal Cancer top of page This page was reviewed on ... with caption Pediatric Content Some imaging tests and treatments have special ... Cancer Images related to Computed Tomography (CT) - Abdomen and ...

  8. Abdominal aspergillosis: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Suk Keu, E-mail: pagoda20@hanmail.net [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Hye Jin, E-mail: kimhyejin@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Byun, Jae Ho, E-mail: jhbyun@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Ah Young, E-mail: aykim@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Lee, Moon-Gyu, E-mail: mglee@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Ha, Hyun Kwon, E-mail: hkha@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of)

    2011-03-15

    Objective: In order to retrospectively evaluate the CT findings of abdominal aspergillosis in immunocompromised patients. Materials and methods: CT scans were reviewed with regard to the sites, number, morphologic appearance, attenuation, and the contrast enhancement patterns of the lesions in six patients (5 women, 1 man; mean age, 43.4 years; range, 23-59 years) with pathologically proved abdominal aspergillosis by two gastrointestinal radiologists in consensus. Medical records were also reviewed to determine each patient's clinical status and outcome. Results: All patients were immunocompromised state: 4 patients received immunosuppressive therapy for solid organ transplantation and 2 patients received chemotherapy for acute myeloid leukemia. Aspergillosis involved blood vessels (n = 3), liver (n = 2), spleen (n = 2), gastrointestinal tract (n = 2), native kidney (n = 1), transplanted kidney (n = 1), peritoneum (n = 1), and retroperitoneum (n = 1). CT demonstrated solid organ or bowel infarction or perforation secondary to vascular thrombosis or pseudoaneurysm, multiple low-attenuating lesions of solid organs presenting as abscesses, concentric bowel wall thickening mimicking typhlitis, or diffuse or nodular infiltration of the peritoneum and retroperitoneum. Conclusion: Familiarity with findings commonly presenting as angioinvasive features or abscesses on CT, may facilitate the diagnosis of rare and fatal abdominal aspergillosis.

  9. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... at and passes through the part of the body being examined, recording an image on a special electronic image recording plate. Bones ...

  10. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... at and passes through the part of the body being examined, recording an image on a special electronic image recording plate. Bones ...

  11. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... at and passes through the part of the body being examined, recording an image on a special electronic image recording plate. Bones ...

  12. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... a relatively short time, especially when compared to magnetic resonance imaging (MRI). CT scanning is painless, noninvasive and accurate. ... the extent of soft tissue of the tumor, magnetic resonance imaging (MRI) may be helpful. A person who is ...

  13. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... and surgical biopsy. No radiation remains in a patient's body after a CT ... side effects. Risks There is always a slight chance of cancer ...

  14. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... and surgical biopsy. No radiation remains in a patient's body after a CT ... side effects. Risks There is always a slight chance of cancer ...

  15. Computed Tomography (CT) -- Sinuses

    Science.gov (United States)

    ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... and surgical biopsy. No radiation remains in a patient's body after a CT ... side effects. Risks There is always a slight chance of cancer ...

  16. Abdominal and Pelvic CT

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    Full Text Available ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... and surgical biopsy. No radiation remains in a patient's body after a CT ... side effects. Risks There is always a slight chance of cancer ...

  17. Computed Tomography (CT) - Spine

    Science.gov (United States)

    ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... and surgical biopsy. No radiation remains in a patient's body after a CT ... side effects. Risks There is always a slight chance of cancer ...

  18. Body CT (CAT Scan)

    Science.gov (United States)

    ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... and surgical biopsy. No radiation remains in a patient's body after a CT ... side effects. Risks There is no conclusive evidence that radiation at ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... can be performed if you have an implanted medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body after ...

  20. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies and needle aspirations of many areas of the ...

  1. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies and needle aspirations of many areas of the ...

  2. Hepatic angiosarcoma: CT findings

    Institute of Scientific and Technical Information of China (English)

    余日胜; 章士正; 华建明

    2003-01-01

    @@ Hepatic angiosarcoma is a rare malignant vascular tumor. Accurate preoperative diagnosis of this tumor is very difficult if the patient does not have any history of exposure to specific carcinogens including thorotrast, arsenicals and vinyl chloride monomer. We describe CT findings in two cases of hepatic angiosarcoma in combination with a review of the literature.

  3. CT image of thymoma

    Energy Technology Data Exchange (ETDEWEB)

    Morioka, Nobuo; Shudo, Yuji; Jahana, Masanobu; Matsuki, Tsutomu; Kotani, Kazuhiko (Tottori Univ., Yonago (Japan). School of Medicine)

    1983-10-01

    Computor tomographic images of 11 patients who had had thymectomy for myasthenia gravis or thymoma were studied retrospectively. Of those 11 patients, malignant thymoma and benign condition including normal thymus were 6 and 5 respectively. On CT, calcification and lobulation with irregular margin seem to be reliable findings of malignancy. Defect or abscence of fatty plane and non-homogenous density are ancillary.

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  6. CT urography and hematuria

    DEFF Research Database (Denmark)

    Bretlau, Thomas; Hansen, Rasmus H; Thomsen, Henrik S

    2015-01-01

    (15%) other disease (i.e. infection or anomaly) was found. No abnormalities were found at CT urography in 455 (58%) of the patients with hematuria. Lesions were found more frequently in patients with visible hematuria than in patients with non-visible hematuria (48% vs. 29%). No malignant tumor...

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... circumstances. For example, sometimes a parent wearing a lead shield may stay in the room with their child. However, the technologist will always be able to see, hear and speak with you through ... to wear a lead apron to minimize radiation exposure. After a CT ...

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... circumstances. For example, sometimes a parent wearing a lead shield may stay in the room with their child. However, the technologist will always be able to see, hear and speak with you through ... to wear a lead apron to minimize radiation exposure. After a CT ...

  9. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... circumstances. For example, sometimes a parent wearing a lead shield may stay in the room with their child. However, the technologist will always be able to see, hear and speak with you through ... to wear a lead apron to minimize radiation exposure. After a CT ...

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  12. Your Radiologist Explains CT Colonography

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    Full Text Available ... is National Prostate Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) Video: Coronary CT Angiography Video: ... is National Prostate Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) Video: Coronary CT Angiography Video: ...

  13. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... also be discussed with the CT technologist or nurse at the time of the CT examination. If ... difficulty breathing, you should notify the technologist or nurse, as it may indicate a more severe allergic ...

  14. Your Radiologist Explains CT Colonography

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    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 ...

  15. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... for a recovery period and will be given instructions on any limitations in activity for the day. ... Images related to Children's (Pediatric) CT (Computed Tomography) Videos related to Children's (Pediatric) CT (Computed Tomography) Sponsored ...

  16. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... What are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  17. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses special x-ray equipment ... period of time. Modern CT scanners are so fast that they can scan through large sections of ...

  18. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  19. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Us News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography ( ... more commonly known as a CT or CAT scan, is a diagnostic medical test that, like traditional ...

  20. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... Sometimes ultrasound is substituted for CT as a method of imaging in these procedures in children. A ...

  1. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... such as inflammation of the bronchi (breathing passages) birth defects trauma to blood vessels or lung CT ... used to: diagnose appendicitis detect abdominal tumors or birth defects In the pelvic region, CT scans can ...

  2. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine ... CT scans should have no immediate side effects. Risks The risk of serious allergic reaction to contrast ...

  3. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ... special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in ...

  4. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... sensitive to radiation, they should have a CT study only if it is essential for making a diagnosis and should not have repeated CT studies unless absolutely necessary. top of page What are ...

  5. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... CT is used to help diagnose a wide range of conditions due to injury or illness. In ... a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to ...

  6. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses special x-ray equipment ... period of time. Modern CT scanners are so fast that they can scan through large sections of ...

  7. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless ... table. Other imaging methods such as ultrasound or magnetic resonance (MR) imaging can provide pictures of certain areas ...

  8. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... sensitive to radiation, they should have a CT study only if it is essential for making a ...

  9. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... to wear a lead apron to prevent radiation exposure. The radiation dose directly outside of the CT ... However, CT scans result in a low-level exposure. Whether such levels cause cancer is debatable but ...

  10. Your Radiologist Explains CT Colonography

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    Full Text Available ... is National Breast Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) Video: Coronary CT Angiography ... is National Breast Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) Video: Coronary CT Angiography ...

  11. Your Radiologist Explains CT Colonography

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    Full Text Available ... Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) Video: Coronary CT Angiography Video: Myelography Video: CT of the Heart Video: Radioiodine I-131 Therapy November 8 is ...

  12. Your Radiologist Explains CT Colonography

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    Full Text Available ... exam, your doctor may restrict you to clear fluids and give you instructions on clearing your colon ... CT Angiography Video: Myelography Video: CT of the Heart Video: Radioiodine I-131 Therapy Radiology and You ...

  13. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... CT scans that are not clearly needed. Another strategy is to consider other tests, such as MRI ... sensitive to radiation, they should have a CT study only if it is essential for making a ...

  14. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... of page What are some common uses of the procedure? CT is used to help diagnose a ... top of page How should we prepare for the CT scan? Your child should wear comfortable, loose- ...

  15. CT colonography: methods, pathology and pitfalls

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.A.; Halligan, S.; Bartram, C.I

    2003-03-01

    Computed tomography colonography (CTC) is a relatively new technique that is currently challenging more established methods of large bowel imaging. Several workers have suggested CTC surpasses the barium enema and approaches conventional endoscopy for detection of colorectal neoplasia. Accurate diagnosis relies on technically good studies, the main aim of which is adequate bowel cleansing and distension. Furthermore, the learning curve is steep and normal colonic anatomy has to be re-learned in a CT context. This review aims to describe the technique, revise the imaging features of both normal and pathological colon, and to highlight potential diagnostic pitfalls and their avoidance.

  16. Combined single photon emission computerized tomography and conventional computerized tomography: Clinical value for the shoulder surgeons?

    Directory of Open Access Journals (Sweden)

    Michael T Hirschmann

    2011-01-01

    Full Text Available With the cases described, we strive to introduce single photon emission computerized tomography in combination with conventional computer tomography (SPECT/CT to shoulder surgeons, illustrate the possible clinical value it may offer as new diagnostic radiologic modality, and discuss its limitations. SPECT/CT may facilitate the establishment of diagnosis, process of decision making, and further treatment for complex shoulder pathologies. Some of these advantages were highlighted in cases that are frequently seen in most shoulder clinics.

  17. Postoperative assessment of surgical results using three dimensional surface reconstruction CT (3D-CT) in a craniofacial anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Jiro; Sato, Kaoru; Nishimoto, Hiroshi; Tsukiyama, Takashi; Fujioka, Mutsuhisa; Akagawa, Tetsuya.

    1988-07-01

    In 1983, Michael W. Vannier and Jeffrey L. Marsh developed a computer method that reconstructs three dimensional (3D) born and soft tissue surfaces, given a high resolution CT scan-series of the facial skeleton. This method has been applied to craniofacial anomalies, basal encephaloceles, and musculoskeletal anomalies. In this study, a postoperative assessment of the craniofacial surgical results has been accomplished using this 3D-CT in 2 children with craniofacial dysmorphism. The authors discuss the advantages of this 3D-CT imaging method in the postoperative assessments of craniofacial anomalies. Results are detailed in the following listing : 1) a postoperative 3D-CT reveals the anatomical details corrected by the craniofacial surgery more precisely and stereographically than conventional radiological methods ; 2) secondary changes of the cranium after the surgery, such as bony formation in the area of the osteotomy and postoperative asymmetric deformities, are detected early by the 3D-CT imaging technique, and, 3) 3D-CT mid-sagittal and top axial views of the intracranial skull base are most useful in postoperative assessments of the surgical results. Basesd on our experience, we expect that three dimensional surface reconstructions from CT scans will become to be used widely in the postoperative assessments of the surgical results of craniofacial anomalies.

  18. CT examinations of healing fractures

    Energy Technology Data Exchange (ETDEWEB)

    Nutz, V.; Uexkuell-Gueldenband, V. v.

    1988-10-01

    The CT appearances of healing fractures were studied following tibial osteotomy in a dog. Traditional radiological investigations and CT were carried out until healing was complete; CT showed callus on the ninth day, whereas radiographs only showed it after 19 days. After 32 days, callus filled nearly the entire medullary cavity. Similar observations were made in several human situations. CT demonstrates interposed material in the fracture very clearly, even if there is marked callus formation within the fracture.

  19. Characterization of Small (Energy CT.

    Science.gov (United States)

    Patel, Bhavik N; Bibbey, Alex; Choudhury, Kingshuk R; Leder, Richard A; Nelson, Rendon C; Marin, Daniele

    2017-10-01

    The purpose of this study is to determine whether single-phase contrast-enhanced dual-energy quantitative spectral analysis improves the accuracy of diagnosis of small (energy attenuation measurements. In this retrospective study, 136 consecutive patients (95 men and 41 women; mean age, 54 years) with 144 renal lesions (111 benign and 33 malignant) underwent single-energy unenhanced and dual-energy contrast-enhanced CT of the abdomen. For each renal lesion, attenuation measurements were obtained, and an attenuation change of 15 HU or greater was considered evidence of enhancement. Dual-energy spectral attenuation curves were generated for each lesion. The slope of each curve was measured between 40 and 50 keV (λHU40-50), 40 and 70 keV (λHU40-70), and 40 and 140 keV (λHU40-140). Mean lesion attenuation values and spectral attenuation curve parameters were compared between benign and malignant renal lesions by use of the two-sample t test. Diagnostic accuracy was assessed and validated using cross-validation analysis. With the use of cross-validated optimal thresholds at 100% sensitivity, specificity for differentiating between benign and malignant renal lesions improved significantly when both λHU40-70 and λHU40-140 were used, compared with conventional enhancement measurements (93% [103/111; 95% CI, 86-97%] vs 81% [90/111; 95% CI, 73-88%]) (p = 0.02). The sensitivity of λHU40-70 and λHU40-140 was also higher than that of conventional enhancement measurements, although it was not statistically significant. Single-phase contrast-enhanced dual-energy quantitative spectral analysis significantly improves the specificity for characterization of small (energy attenuation measurements.

  20. Empirical beam hardening correction (EBHC) for CT

    Energy Technology Data Exchange (ETDEWEB)

    Kyriakou, Yiannis; Meyer, Esther; Prell, Daniel; Kachelriess, Marc [Institute of Medical Physics, University of Erlangen-Nuernberg, 91052 Erlangen (Germany)

    2010-10-15

    C-arm CT scanner (Axiom Artis dTA, Siemens Healthcare, Forchheim, Germany). A large variety of phantom, small animal, and patient data were used to demonstrate the data and system independence of EBHC. Results: Although no physics apart from the initial segmentation procedure enter the correction process, beam hardening artifacts were significantly reduced by EBHC. The image quality for clinical CT, micro-CT, and C-arm CT was highly improved. Only in the case of C-arm CT, where high scatter levels and calibration errors occur, the relative improvement was smaller. Conclusions: The empirical beam hardening correction is an interesting alternative to conventional iterative higher order beam hardening correction algorithms. It does not tend to over- or undercorrect the data. Apart from the segmentation step, EBHC does not require assumptions on the spectra or on the type of material involved. Potentially, it can therefore be applied to any CT image.

  1. Technical aspects of CT scanning.

    Science.gov (United States)

    Maravilla, K R; Pastel, M S

    1978-01-01

    The advent of computed tomography (CT) has initiated a technological revolution which continues to the present time. A brief review of basic principles of CT scanning is presented, and the evolution of modern CT scanner systems is traced. Some early indications of future trends are also presented.

  2. Venous thromboembolic disease. CT evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, L. R. [Medical College of Wisconsin, Pulmonary Medicine and Intensive Care, Dept. of Diagnostic Radiology, Milwaukee, WI (United States)

    2001-12-01

    Helical and multidetector CT has proven to be a valuable imaging modality for both pulmonary embolism and deep venous thrombosis. This paper will review the sensitivity and specificity of CT and discuss diagnostic algorithms utilizing CT and more established imaging technologies.

  3. 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

  4. Conventional four field radiotherapy versus computed tomography-based treatment planning in cancer cervix: A dosimetric study

    Directory of Open Access Journals (Sweden)

    Abhishek Gulia

    2013-01-01

    Full Text Available Background: With advancements in imaging, wide variations in pelvic anatomy have been observed, thus raising doubts about adequate target volume coverage by conventional external radiotherapy fields based on bony landmarks. The present study evaluates the need for integrating computed tomography (CT-based planning in the treatment of carcinoma cervix. Aims: To estimate inadequacies in target volume coverage when using conventional planning based on bony landmarks. Materials and Methods: The study consisted of 50 patients. Target volume delineation was done on planning CT scans, according to the guidelines given in literature. The volume of target receiving 95% of prescribed dose (V95 was calculated after superimposing a conventional four field box on digitally reconstructed radiograph. The geographic miss with conventional four field box technique was compared with the CT-based target volume delineation. Results: In 48 out of 50 patients, the conventional four field box failed to encompass the target volume. The areas of miss were at the superior and lateral borders of the anterior-posterior fields, and the anterior border of the lateral fields. The median V95 for conventional fields marked with bony landmarks was only 89.4% as compared to 93% for target delineation based on CT contouring. Conclusions: Our study shows inadequate target volume coverage with conventional four field box technique. We recommend routine use of CT-based planning for treatment with radiotherapy in carcinoma cervix.

  5. Three-dimensional CT of the ossicles of the middle ear

    Energy Technology Data Exchange (ETDEWEB)

    Edamatsu, Hideo; Yamashita, Koichi [Kanazawa Medical Univ., Uchinada, Ishikawa (Japan)

    1995-02-01

    This study was performed to evaluate the usefulness and limitations of three-dimensional (3-D) imaging of the ossicular chain in the middle ear by high speed helical CT. One dissected human temporal bone, five normal ears, and twelve diseased ears (trauma, ossicular anomaly, cholesteatoma, chronic otitis media) were scanned in 1.0 mm slices and reconstructed at a thickness of 0.2-0.5 mm. All 3-D CT specimens can be observed in any plane and from any direction. Ossicular 3-D CT temporal bone images were reconstructed as if the malleus, incus and stapes were being observed under a microscope. No defect in the ossicles or their joints was seen in the images. The entire structure of the stapes could not be represented by conventional two-dimensional CT, but the 3-D CT in our study showed the head, crus and foot plate of the stapes in detail. Ossicular 3-D CT images of normal ears yielded the same findings as those recorded in the temporal bone. Preoperative diagnostic findings of ossicles in diseased ears were very useful. 3-D CT was diagnostic and its accuracy was confirmed by surgical observations, especially in ossicular anomalies. 3-D CT was also an important method of postoperative evaluation of ossicular reconstruction, i.e. TORP and PORP. It could represent the anatomical relation between prosthesis and the oval window. Postoperative hearing improvement can be compared with 3-D CT findings. High-speed helical CT can scan an object more quickly and clearly than conventional CT, and its biological damage in humans is less than that of other methods. 3-D CT allows obviously clearer reconstruction by helical CT than the other methods. (author).

  6. A prospective evaluation of conventional cystography for detection of urine leakage at the vesicourethral anastomosis site after radical prostatectomy based on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Han, K.S. [Urologic Oncology Clinic, Center for Prostate Cancer, National Cancer Center, 809 Madu-dong, Ilsan-dong-gu, Goyang-si, Gyeonggi-do 411-769, Goyang (Korea, Republic of); Choi, H.J. [Department of Radiology, Asan Medical Center, University of Ulsan, Seoul (Korea, Republic of); Jung, D.C. [Department of Radiology, Center for Specific Organs Cancer, National Cancer Center, Goyang (Korea, Republic of); Park, S. [Cancer Registration and Biostatistics Branch, National Cancer Center, Goyang (Korea, Republic of); Cho, K.S.; Joung, J.Y.; Seo, H.K.; Chung, J. [Urologic Oncology Clinic, Center for Prostate Cancer, National Cancer Center, 809 Madu-dong, Ilsan-dong-gu, Goyang-si, Gyeonggi-do 411-769, Goyang (Korea, Republic of); Lee, K.H., E-mail: uroonco@ncc.re.k [Urologic Oncology Clinic, Center for Prostate Cancer, National Cancer Center, 809 Madu-dong, Ilsan-dong-gu, Goyang-si, Gyeonggi-do 411-769, Goyang (Korea, Republic of)

    2011-03-15

    Aim: To evaluate the diagnostic accuracy of conventional cystography for the detection of urine leakage at the vesicourethral anastomosis (VUA) site after radical prostatectomy based on computed tomography (CT) cystography. Materials and methods: Patients who underwent radical prostatectomies at a single tertiary cancer centre were prospectively enrolled. Conventional cystography was routinely performed on postoperative day 7. Non-enhanced pelvic CT images were obtained after retrograde instillation of the same contrast material for a reference standard of urine leakage at the VUA site. Urine leakage was classified as follows: none; a plication abnormality; mild; moderate; and excessive. Results: One hundred and twenty consecutive patients were enrolled. Conventional cystography detected 14 urine leakages, but CT cystography detected 40 urine leakages, which consisted of 28 mild and 12 moderate urine leakages. When using CT cystography as the standard measurement, conventional cystography showed a diagnostic accuracy of 17.8% (5/28) for mild urine leakage and 75% (9/12) for moderate leakage. Of nine patients diagnosed with mild leakage on conventional cystography, four (44.4%) had complicated moderate urine leakages based on CT cystography, requiring prolonged catheterization. The sensitivity, specificity, positive and negative predictive values, and accuracy of conventional cystography were 35, 100, 100, 75.4, and 78.3%, respectively. Conclusions: Conventional cystography is less accurate than CT cystography for diagnosing urine leakage at the VUA site after a radical prostatectomy. The present results suggest that CT cystography is a good choice for diagnostic imaging of urine leakage after radical prostatectomy.

  7. CT classification of acetabular fractures

    Energy Technology Data Exchange (ETDEWEB)

    Marincek, B.; Porcellini, B.; Robotti, G.

    1984-05-01

    The contribution of computed tomography (CT) in classifying acetabular fractures was analysed retrospectively in 33 cases. CT and plain radiography classification agreed in 27 cases (82%). CT revealed more extensive fractures in 6 patients (thereof 5 patients with associated fractures). In 10 patients (thereof 9 patients with associated fractures) CT showed intraarticular fragments; radiographically intraarticular fragments were seen only in 2 patients and suspected in 4. CT is of considerable aid in defining the fracture pattern. It should be used mainly in patients with radiographically difficult interpretable associated fractures in order to assess preoperatively the weight-bearing part of the acetabulum, the degree of displacement and the presence of intraarticular fragments.

  8. Dynamic CT myocardial perfusion imaging.

    Science.gov (United States)

    Caruso, Damiano; Eid, Marwen; Schoepf, U Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie; Spandorfer, Adam; Laghi, Andrea; De Cecco, Carlo N

    2016-10-01

    Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  9. Diagnostic significance of gas distension technique of the stomach with gas-forming agent on CT scan of stomach cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rho, Tae Jin; Song, Chang June; Choi, Joong Chan; Park, Cheong Hee; Cho, June Sik; Rhee, Byung Chull [Chungnam National University College of Medicine, Dajeon (Korea, Republic of)

    1988-10-15

    CT is a valuable method for preoperative staging of patients with stomach cancers. However, in patients with poor distension of the stomach and scanty fat between the stomach and adjacent organs, CT findings may indicate a false impression of gastric wall thickening and cannot provide the precise extent of stomach cancer. We studied the usefulness of gastric distension by gas-forming agent in 28 cases of pathologically confirmed gastric cancers on CT. Comparative analysis between CT findings and surgical pathologic findings was done in 22 cases who underwent surgery. The results were as follows; 1. Conventional CT failed to define the wall thickening or masses of the stomach, in 14 cases of 23 advanced gastric cancers, while CT with gas distension technique allowed good visualization in all advanced gastric cancers. 2. In 2 cases of 5 early gastric cancers, CT with gas distension technique could detect focal thickening of the gastric wall, even less than 1cm thickness. 3. Among 13 cases with indistinguishable border between stomach and liver on conventional CT, 7 cases were diagnosed as negative invasion on CT with gas distension technique and 5 cases of these were confirmed by surgery. 4. Among 11 cases with indistinguishable border between stomach and pancreas on conventional CT, 3 cases were diagnosed as negative invasion on CT with gas distension technique, all of which were confirmed by surgery. 5. There was no significant difference between conventional CT and CT with gas distension technique of the stomach to diagnose invasion into transverse colon, transverse colon, transverse mesocolon, lymph node metastasis, and various distant metastasis.

  10. Helical CT for lumbosacral spinal

    Energy Technology Data Exchange (ETDEWEB)

    Tatsuno, Satoshi; Fukuda, Kunihiko [Jikei Univ., Tokyo (Japan). School of Medicine

    1996-10-01

    The aim of this study was to investigate the efficacy of helical CT for lumbosacral pathology. We performed helical CT with multiplanar reconstruction, including the formation of oblique transaxial and coronal images, in 62 patients with various lumboscral disorders, including 32 non-enhanced CT and 36 CT after myelography. We correlated the appearance of the stenotic spinal canal and neoplastic disease with the findings on MRI obtained at nearly the same time. We obtained helical CT images in all cases in about 30 seconds. The diagnostic ability of helical CT was roughly equal to that of MRI in patients with spondylosis deformans, spondylolisthesis and herniated nucleus pulposus. There was no significant difference in diagnostic value for degenerative lumbosacral disease with canal and foraminal stenosis between non-enhanced and post-myelography helical CT. However, non-enhanced helical CT could not clearly demonstrate neoplastic disease because of the poor contrast resolution. Helical CT was useful in evaluating degenerative disorder and its diagnostic value was nearly equal to that of MRI. We considered that helical CT may be suitable for the assessment of patients with severe lumbago owing to the markedly shortened examination time. However, if helical CT is used as a screening method for lumbosacral disease, one must be careful of its limitations, for example, poor detectability of neoplastic disease, vascular anomalies and so on. (author)

  11. The purpose of this study is to determine the clinical usefulness of Valsalva maneuver (VM) to evaluate piriform-fossae lesions on helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Shoji; Yasuda, Shigeo; Kimura, Shinjiro; Ito, Hisao [Chiba Univ. (Japan). Hospital; Fujimoto, Hajime; Nasu, Katsuhiro; Motoori, Ken

    1997-07-01

    Forty-four patients who were suspected hypopharyngeal carcinoma underwent both conventional CT under quiet breath holding and helical CT under Valsalva maneuver (VMCT). All patients successfully performed Valsalva maneuver during image acquisition. Normal piriform fossae were dilated well under VM. Five fossae involved by hypopharyngeal carcinoma were poorly dilated on VMCT. In conclusion VMCT is a supportive method to evaluate piriform fossae. If piriform fossae lesions were suspected on conventional CT, VMCT should be performed. (author)

  12. CT in the diagnosis of colonic diverticulitis

    Energy Technology Data Exchange (ETDEWEB)

    Narumi, Yoshifumi; Mitani, Takashi; Kuriyama, Keiko

    1987-11-01

    Pericolic abscess is the most frequent complication of colonic diverticulitis which requires an accurate diagnosis on its location, extent, and complications. Double-contrast barium enema (DCBE) was able to reveal indirect signs such as displacement of the colon and contrast material in the abscess cavity. Conventional Computed tomography (CT) of the colon could not demonstrate a pericolic abscess and thickened colonic wall clearly. We tried to demonstrate direct signs of pericolic abscess and thickened colonic wall by administering 200 ml of olive oil per anum. Additionally, to demonstrate the fistulous tract between sigmoid colon and urinary bladder, 200 ml of 0.8% barium solution was administered first per anum, and then evacuated prior to administering olive oil. The DCBE and CT examination in 4 patients with a clinical diagnosis (2 cases) or surgically confirmed diagnosis (2 cases) of colonic diverticulitis were studied to determine the sensitivity of the two technics. Our results showed that CT was significantly superior to the DCBE in visualising the location and extent of pericolic inflammatory process, especially colovesical fistula, the most severe complication of pericolic abscess.

  13. CT of pancreatitis

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Toshio (Nagasaki Univ. (Japan). School of Medicine)

    1990-09-01

    One hundred and two cases of acute and chronic pancreatitis were studied by computed tomography. Fluid collection was detected by CT in 45 cases, and the common extrapancreatic sites of involvement included the lesser sac (13 cases), anterior pararenal space (9 cases), transverse mesocolon (7 cases) and posterior pararenal space (5 cases). Ten cases of spontaneous resolution of pancreatic pseudocysts were encountered. Cystojejunostomy was done on 6 patients. A 4-to-6-weeks time interval has been currently accepted as necessary for pseudocyst wall maturation. However, the surgery was not possible in two patients in this series since the cyst wall was too thin. It is considered that the time over 3 months is required for surgical anastomosis of the cyst to the gastrointestinal tract. Pancreatic abscess has become the most common cause of death from pancreatitis. In this series pancreatic abscess occurred in 8 patients. Gas collection in the pancreas was observed in only one patient. In the other patients, pseudocysts had become infected and converted to abscesses. The CT number of 4 infected pseudocysts was less than 15 HU. Thus, it was not possible to distinguish infected from noninfected pseudocysts by CT. The author studied 9 patients with focal inflammatory mass of the pancreas with histologically proved severe fibrosis. All masses were small. Angiography showed occlusion or marked stenosis of the splenic vein in 3 cases. The postcontract CT (after intravenous bolus injection) in 7 cases of focal inflammatory mass demonstrated almost equal enhanced effect of the mass as compared with the adjacent normal pancreatic parenchyma. This finding is considered to be useful in distinguishing inflammatory mass from pancreatic carcinoma. (author).

  14. The Appendix on CT

    Energy Technology Data Exchange (ETDEWEB)

    Whitley, S. [Sunnybrook Health Sciences Center, Toronto, Ontario (Canada); Barts and the Royal London, Royal London Hospital, Whitechapel, London (United Kingdom)], E-mail: siobhanwhitley@yahoo.co.uk; Sookur, P.; McLean, A.; Power, N. [Barts and the Royal London, Royal London Hospital, Whitechapel, London (United Kingdom)

    2009-02-15

    Appendicitis can be a difficult clinical diagnosis to make. A negative appendicectomy rate of 20% has traditionally been accepted as the consequences of appendiceal perforation can be grave. Cross-sectional imaging is increasingly being employed in the investigation of adults with suspected appendicitis. This review will demonstrate the appearance of the normal appendix on computed tomography (CT) and its appearance in a range of inflammatory and neoplastic processes including appendicitis, Crohn's disease, infections, and benign and malignant tumour000.

  15. CT diagnosis in the evaluation of vertebral trauma

    Energy Technology Data Exchange (ETDEWEB)

    Emori, Takumi; Kadoya, Satoru; Nakamura, Tsutomu; Ito, Shotaro; Kwak, Ryungchan

    1984-12-01

    The diagnostic capability of the CT scan of the vertebral trauma and a comparison with the results of a routine roentgenogram and tomogram were studied in 11 patients. In total, there were 15 fractured vertebrae: 3 in the upper cervical, 3 in the lower cervical, and 9 in the thoracic and thoraco-lumbar vertebrae. In the detailed evaluation of the vertebral fractures, CT provided more information than plain films in all 15 fractured vertebrae, with a better visualization of the spinal bony details, particularly at the upper cervical, thoracic, and thoraco-lumbar levels, where the interpretation of the spinal abnormalities is usually difficult because of adjacent structures such as the skull and thorax. Only CT was able to demonstrate impingements on the vertebral canal by bony fragments. Post-traumatic syringomyelia was incidentally demonstrated in one patient on a plain CT. In 6 patients, conventional tomography was done, but no additional information with regard to spinal instability and spinal-cord compression was obtained. The usage of sagittal tomography was also limited, because it required a change in the patient's position, which might worsen the neurological deficits. On the other hand, a plain roentgenogram and conventional tomography were superior in the evaluation of spinal malalignment and fractures running horizontally. In summary, both plain roentgenograms and CT images provided detailed information about vertebral injury, whereas conventional tomography is judged to be inferior and not always necessary. Based on these results, our new diagnostic and therapeutic approaches using CT for the vertebral injuries were presented.

  16. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... as organ transplants. stage, plan and properly administer radiation treatments for tumors as well as monitor response ... conventional x-ray exam, a small amount of radiation is aimed at and passes through the part ...

  17. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... conventional x-ray exam, a small amount of radiation is aimed at and passes through the part ... detectors rotate around you, measuring the amount of radiation being absorbed throughout your body. Sometimes, the examination ...

  18. CT-scanning of ancient Greenlandic Inuit temporal bones

    DEFF Research Database (Denmark)

    Homøe, P; Lynnerup, N; Videbaek, H

    1992-01-01

    bones. The CT-scans showed sclerosing and obliteration of the air cells and even destruction of the cellular septae, and a high degree of irregularity of the cells. Sclerosing of the surrounding bone tissue was also found. The findings in one cranium were dubious and could both be regarded...... as a congenital malformation or an infection in infanthood. CT-scan confirms and even adds to the results of conventional X-ray of temporal bones making hypotheses of paleopathology more reliable. The findings also support the environmental theory of pneumatization of the air cell system in the temporal bones....

  19. Sacroiliitis in Ankylosing Spondylitis: Comparison with Multidetector Row CT and Plain Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ji Youn; Joo, Kyung Bin; Choi, Byeong Kyoo; Ryu, Jeong Ah; Kim, Tae Hwan; Choi, Woo Jung [Hanyang University Hospital, Seoul (Korea, Republic of)

    2009-03-15

    The objective of our study was to compare multidetector row CT and the plain radiographs for making the diagnosis and grading the sacroiliitis that accompanies ankylosing spondylitis. We wanted to determine the role of multidetector row CT for the evaluation of the sacroilitis in patients with ankylosing spondylitis. One hundred ninety two patients with clinically suspected ankylosing spondylitis were evaluated by conventional radiography and multidetector row CT. Two musculoskeletal radiologists retrospectively analyzed the images, and they graded the sacroiliitis using the modified New York Criteria. Multidetector row CT demonstrated a significantly higher sensitivity (74.5%, 83.3%) than did plain radiography (59.9%, 66.7%) for detecting early sacroiliitis (p<0.05). Multidetector row CT showed a higher grade of sacroiliitis in 114 and 127 of 384 sacroiliac joints. Performing multidetector row CT rather than plain radiography for making the diagnoses of accompanying ankylosing spondylitis allows an early start of treatment with a subsequently improved prognosis

  20. Comparison of Computed Tomography Scout Based Reference Point Localization to Conventional Film and Axial Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Lan; Templeton, Alistair; Turian, Julius; Kirk, Michael; Zusag, Thomas; Chu, James C.H., E-mail: jchu@rush.edu

    2011-01-01

    Identification of source positions after implantation is an important step in brachytherapy planning. Reconstruction is traditionally performed from films taken by conventional simulators, but these are gradually being replaced in the clinic by computed tomography (CT) simulators. The present study explored the use of a scout image-based reconstruction algorithm that replaces the use of traditional film, while exhibiting low sensitivity to metal-induced artifacts that can appear in 3D CT methods. In addition, the accuracy of an in-house graphical software implementation of scout-based reconstruction was compared with seed location reconstructions for 2 phantoms by conventional simulator and CT measurements. One phantom was constructed using a planar fixed grid of 1.5-mm diameter ball bearings (BBs) with 40-mm spacing. The second was a Fletcher-Suit applicator embedded in Styrofoam (Dow Chemical Co., Midland, MI) with one 3.2-mm-diameter BB inserted into each of 6 surrounding holes. Conventional simulator, kilovoltage CT (kVCT), megavoltage CT, and scout-based methods were evaluated by their ability to calculate the distance between seeds (40 mm for the fixed grid, 30-120 mm in Fletcher-Suit). All methods were able to reconstruct the fixed grid distances with an average deviation of <1%. The worst single deviations (approximately 6%) were exhibited in the 2 volumetric CT methods. In the Fletcher-Suit phantom, the intermodality agreement was within approximately 3%, with the conventional sim measuring marginally larger distances, with kVCT the smallest. All of the established reconstruction methods exhibited similar abilities to detect the distances between BBs. The 3D CT-based methods, with lower axial resolution, showed more variation, particularly with the smaller BBs. With a software implementation, scout-based reconstruction is an appealing approach because it simplifies data acquisition over film-based reconstruction without requiring any specialized equipment

  1. The role of CT discography in far lateral disk herniation

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Hyun Shim; Yun, Seung Soo; Park, Jun Kyun; Kim, Young Chul; Kim, Young Sook; Oh, Jae Hee [College of Medicine, Chosun University, Kwangju (Korea, Republic of)

    1995-10-15

    To evaluate the value and the radiologic findings of CT discography in the diagnosis of the far lateral disk herniation. We retrospectively reviewed 7 cases of surgically proven far lateral lumbar disc herniation. CT discography was performed for all cases. Four cases underwent conventional CT and three cases MRI as a primary diagnostic imaging method. Far lateral diac herniation was divided into 3 groups by location; Intraforaminal herniation, extraforaminal herniation, and mixed type. We analyzed the findings of CT discography including location and extent of far lateral disc herniation. In all 7 cases, CT discography clearly demonstrated the filling of contrast media in laterally-protruded disc material. Intraforaminal and extraforminal types were seen in 2 cases each, and mixed type in 3 cases. Subligamentous herniated nucleus pulposus was present in 6 cases and extruded disc in 1 cases. Far lateral disc herniation was located at L4-5 in 5 cases and L5-S1 in 2 cases. CT discography can help establishing accurate preoperative diagnosis for far lateral disc herniation.

  2. Lumbar CT findings of patients with low back pain

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Chul; Kim, Yang Soo; Kim, Kyun Sang [Chung-Ang University, Seoul (Korea, Republic of)

    1986-04-15

    Low back pain is probably the second most common disease entity to upper respiratory infection in developed country. We were missing at least 50% of the pathologic conditions by using conventional diagnostic modalities in low back pain. They did tell us nothing or little about facet abnormalities, lateral recesses, vertebral canal and soft tissue surrounding lumbar spines. High resolutional CT has been the biggest turning point in the diagnosis and management of low back pain. CT make a contribution to reducing the morbidity and probably the cost of evaluating patients with low back pain, and to increasing diagnostic accuracy. We observed 100 cases of lumbar CT using TCT 80A scanner for the evaluation of low back pain during the period from Apr. 1985 to Sept. 1985 at Chung-Ang University Hospital. Lumbar CT scan reveals high-positive findings (98%) in low back pain patients. Common low back disorders in CT are disc bulging (53%), herniated nucleus pulposus (32%), degenerative arthritis in posterior facet joints (27%), spinal stenosis (20%) and postoperative spines (15%). Uncommon low back disorders in CT are compression fracture of vertebral bodies, spondylolysis or spondylolisthesis, tropism, transitional vertebra, Scheueman's disease, limbic fracture, transverse process or articular process fracture, sacroiliac joint subluxation, conjoined nerve root and meningocele.

  3. CONVENTIONAL DEVELOPMENT OF ENVIRONMENTAL PREOCCUPATIONS

    OpenAIRE

    2011-01-01

    A great number of the conventions referring to nature, even if they do not refer ton particular species, were limited from the point of view of geography and territories: we may give as example here a convention for the protection of flora, fauna and panoramic beauties of America, the African convention for nature and natural resources… By the Stockholm conferences, from the 5th of June 1972, we entered in a “dynamic of globalization”. Article 1 of the Declaration that followed the conference...

  4. Conventional Armaments for coming decades .

    Directory of Open Access Journals (Sweden)

    S.K. Salwan

    1997-10-01

    Full Text Available Conventional arnaments have continued to play a decisive role even in the present scenario of nuclear weapons and electronic warfare. As a war-fighting technology, they are low cost, reliable, highly effective and proven in several battlefield situations. With the application of advancements in electronics, materials and manufacturing technologies, computers and propulsion technologies to conventional weapon systems, they are capable of having greater flexibility, lethality , accuracy and effectiveness. This communication gives an overview on advancements in conventional armament systems, emerging trends in weapon technologies and modern enabling technologies for advanced weapon systems.

  5. Comparison of cone-beam CT-guided and CT fluoroscopy-guided transthoracic needle biopsy of lung nodules

    Energy Technology Data Exchange (ETDEWEB)

    Rotolo, Nicola; Imperatori, Andrea; Arlant, Veronica; Dominioni, Lorenzo [Insubria University, Center for Thoracic Surgery, Varese (Italy); Floridi, Chiara; Fontana, Federico; Ierardi, Anna Maria; Mangini, Monica; De Marchi, Giuseppe; Fugazzola, Carlo; Carrafiello, Gianpaolo [Insubria University, Radiology Department, Varese (Italy); Novario, Raffaele [Insubria University, Medical Physics Department, Varese (Italy)

    2016-02-15

    To compare the diagnostic performance of cone-beam CT (CBCT)-guided and CT fluoroscopy (fluoro-CT)-guided technique for transthoracic needle biopsy (TNB) of lung nodules. The hospital records of 319 consecutive patients undergoing 324 TNBs of lung nodules in a single radiology unit in 2009-2013 were retrospectively evaluated. The newly introduced CBCT technology was used to biopsy 123 nodules; 201 nodules were biopsied by conventional fluoro-CT-guided technique. We assessed the performance of the two biopsy systems for diagnosis of malignancy and the radiation exposure. Nodules biopsied by CBCT-guided and by fluoro-CT-guided technique had similar characteristics: size, 20 ± 6.5 mm (mean ± standard deviation) vs. 20 ± 6.8 mm (p = 0.845); depth from pleura, 15 ± 15 mm vs. 15 ± 16 mm (p = 0.595); malignant, 60 % vs. 66 % (p = 0.378). After a learning period, the newly introduced CBCT-guided biopsy system and the conventional fluoro-CT-guided system showed similar sensitivity (95 % and 92 %), specificity (100 % and 100 %), accuracy for diagnosis of malignancy (96 % and 94 %), and delivered non-significantly different median effective doses [11.1 mSv (95 % CI 8.9-16.0) vs. 14.5 mSv (95 % CI 9.5-18.1); p = 0.330]. The CBCT-guided and fluoro-CT-guided systems for lung nodule biopsy are similar in terms of diagnostic performance and effective dose, and may be alternatively used to optimize the available technological resources. (orig.)

  6. Evaluation of CT-based SUV normalization

    Science.gov (United States)

    Devriese, Joke; Beels, Laurence; Maes, Alex; Van de Wiele, Christophe; Pottel, Hans

    2016-09-01

    The purpose of this study was to determine patients’ lean body mass (LBM) and lean tissue (LT) mass using a computed tomography (CT)-based method, and to compare standardized uptake value (SUV) normalized by these parameters to conventionally normalized SUVs. Head-to-toe positron emission tomography (PET)/CT examinations were retrospectively retrieved and semi-automatically segmented into tissue types based on thresholding of CT Hounsfield units (HU). The following HU ranges were used for determination of CT-estimated LBM and LT (LBMCT and LTCT):  -180 to  -7 for adipose tissue (AT), -6 to 142 for LT, and 143 to 3010 for bone tissue (BT). Formula-estimated LBMs were calculated using formulas of James (1976 Research on Obesity: a Report of the DHSS/MRC Group (London: HMSO)) and Janmahasatian et al (2005 Clin. Pharmacokinet. 44 1051-65), and body surface area (BSA) was calculated using the DuBois formula (Dubois and Dubois 1989 Nutrition 5 303-11). The CT segmentation method was validated by comparing total patient body weight (BW) to CT-estimated BW (BWCT). LBMCT was compared to formula-based estimates (LBMJames and LBMJanma). SUVs in two healthy reference tissues, liver and mediastinum, were normalized for the aforementioned parameters and compared to each other in terms of variability and dependence on normalization factors and BW. Comparison of actual BW to BWCT shows a non-significant difference of 0.8 kg. LBMJames estimates are significantly higher than LBMJanma with differences of 4.7 kg for female and 1.0 kg for male patients. Formula-based LBM estimates do not significantly differ from LBMCT, neither for men nor for women. The coefficient of variation (CV) of SUV normalized for LBMJames (SUVLBM-James) (12.3%) was significantly reduced in liver compared to SUVBW (15.4%). All SUV variances in mediastinum were significantly reduced (CVs were 11.1-12.2%) compared to SUVBW (15.5%), except SUVBSA (15.2%). Only SUVBW and SUVLBM-James show

  7. Single-center study comparing computed tomography colonography with conventional colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Ian C Roberts-Thomson; Graeme R Tucker; Peter J Hewett; Peter Cheung; Ruben A Sebben; EE Win Khoo; Julie D Marker; Wayne K Clapton

    2008-01-01

    AIM: To compare the results from computed tomography (CT) colonography with conventional colonoscopy in symptomatic patients referred for colonoscopy. METHODS: The study included 227 adult outpatients, mean age 60 years, with appropriate indications for colonoscopy. CT colonography and colonoscopy were performed on the same day in a metropolitan teaching hospital. Colonoscopists were initially blinded to the results of CT colonography but there was segmental unblinding during the procedure. The primary outcome measures were the sensitivity and specificity of CT colonography for the identification of polyps seen at colonoscopy (i.e. analysis by polyp). Secondary outcome measures included an analysis by patient, extracolonic findings at CT colonography, adverse events with both procedures and patient acceptance and preference. RESULTS: Twenty-five patients (11%) were excluded from the analysis because of incomplete colonoscopy or poor bowel preparation that affected either CT colonography, colonoscopy or both procedures. Polyps and masses (usually cancers) were detected at colonoscopy and CT colonography in 35% and 42% of patients, respectively. Of nine patients with a final diagnosis of cancer, eight (89%) were identified by CT colonography as masses (5) or polyps (3). For polyps analyzed according to polyp, the overall sensitivity of CT colonography was 50% (95% CI, 39%-61%) but this increased to 71% (95% CI, 52%-85%) for polyps ≥ 6 mm in size. Similarly, specificity for all polyps was 48% (95% CI, 39%-58%) increasing to 67% (95% CI, 56%-76%) for polyps ≥ 6 mm. Adverse events were uncommon but included one colonic perforation at colonoscopy, Patient acceptance was high for both procedures but preference favoured CT colonography. CONCLUSION: Although CT colonography was more sensitive in this study than in some previous studies, the procedure is not yet sensitive enough for widespread application in symptomatic patients.

  8. Provision of CT Scanning Capability to VA/DoD (Veterans Administration/ Department of Defense) Health Care Facilities through a Shared Mobile CT Unit: A Feasibility Study

    Science.gov (United States)

    1984-07-27

    Hill, Alan L.; and Lange , Paul H. "Use of CT to Reduce Understaging in Prostatic Cancer: Comparison with Conventional Staging Techniques." American...November 1982): 427-29. 24. Firooznia, Hossein; Benjamin, Vallo; Kricheff, Irvin I.; Rafii, Mahvash; and Golimbu, Cornelia . "CT of Lumbar Spine Disk...Lloyd and Abernathy, David L. "Diagnostic Imaging Procedures Volume in the United States." Radiology 146 (March 1983): 851-3. 36. Lang , Eric K. "Angio

  9. NULL Convention Floating Point Multiplier

    OpenAIRE

    Anitha Juliette Albert; Seshasayanan Ramachandran

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to p...

  10. A comparative study of the diagnostic accuracy on Waters view with CT scan in detecting midface fractures

    OpenAIRE

    Panjnoush M.; Shirani Gh.; Jozghanbari P.

    2006-01-01

    Background and Aim: In recent years, CT scan has become available as an alternative to conventional radiography. To date, the utility of Waters view in detecting midface fractures has been rarely evaluated. The aim of this study was to compare the diagnostic accuracy and reliability of Waters radiography with CT scan in detecting midface fractures. Materials and Methods: In this tests evaluation study, waters view and CT scan were performed for 42 patients with midface fracture admitted to ma...

  11. A review on the clinical uses of SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Mariani, Giuliano; Bruselli, Laura [University of Pisa Medical School, Regional Center of Nuclear Medicine, Pisa (Italy); Kuwert, Torsten [Friedrich-Alexander-University, Clinic of Nuclear Medicine, Erlangen-Nuremberg (Germany); Kim, Edmund E. [MD Anderson Cancer Center, Nuclear Medicine Service, Houston, TX (United States); Flotats, Albert [Universitat Autonoma de Barcelona, Hospital de Sant Pau, Nuclear Medicine Department, Barcelona (Spain); Israel, Ora [Rambam Health Care Campus, Department of Nuclear Medicine, Haifa (Israel); Dondi, Maurizio [International Atomic Energy Agency, Nuclear Medicine Section, Division of Human Health, Vienna (Austria); Watanabe, Naoyuki [International Atomic Energy Agency, Nuclear Medicine Section, Division of Human Health, Vienna (Austria); Gunma Prefectural College of Health Sciences, Department of Radiological Technology, Gunma (Japan)

    2010-10-15

    In the era when positron emission tomography (PET) seems to constitute the most advanced application of nuclear medicine imaging, still the conventional procedure of single photon emission computed tomography (SPECT) is far from being obsolete, especially if combined with computed tomography (CT). In fact, this dual modality imaging technique (SPECT/CT) lends itself to a wide variety of useful diagnostic applications whose clinical impact is in most instances already well established, while the evidence is growing for newer applications. The increasing availability of new hybrid SPECT/CT devices with advanced technology offers the opportunity to shorten acquisition time and to provide accurate attenuation correction and fusion imaging. In this review we analyse and discuss the capabilities of SPECT/CT for improving sensitivity and specificity in the imaging of both oncological and non-oncological diseases. The main advantages of SPECT/CT are represented by better attenuation correction, increased specificity, and accurate depiction of the localization of disease and of possible involvement of adjacent tissues. Endocrine and neuroendocrine tumours are accurately localized and characterized by SPECT/CT, as also are solitary pulmonary nodules and lung cancers, brain tumours, lymphoma, prostate cancer, malignant and benign bone lesions, and infection. Furthermore, hybrid SPECT/CT imaging is especially suited to support the increasing applications of minimally invasive surgery, as well as to precisely define the diagnostic and prognostic profile of cardiovascular patients. Finally, the applications of SPECT/CT to other clinical disorders or malignant tumours is currently under extensive investigation, with encouraging results in terms of diagnostic accuracy. (orig.)

  12. CT findings as confirmatory criteria of brain death

    Energy Technology Data Exchange (ETDEWEB)

    Shiogai, Toshiyuki; Takeuchi, Kazuo (Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine)

    1983-12-01

    The absence of cerebral circulation and electrocerebral silence have served as an accurate index of irreversible brain death. It is proposed that computed tomography (CT) findings be evaluated as confirmatory criteria of brain death. To this end, CT evaluation of 14 patients satisfying the conventional criteria of brain death was performed. A CT finding of severe compression or dissappearance of the ventricular system, or so called ''brain tamponade'', was seen in 7 (50 %) of the 14 patients. Enhanced contrast CT, especially dynamic CT, usually distinctly reveals the cerebral vessels whenever the cerebral blood flow is preserved; conversely, the lack of enhanced brain structures, even comparing attenuation values, indicates the absence of cerebral blood flow. In 7 (70 %) of 10 patients, however, there was enhanced contrast of vascular brain structures, especially the circle of Willis, major cerebral arteries, choroid plexuses, and venous sinuses. It is suggested that this result is due to the improvement of demonstrability by CT. The usefulness of CT in the confirmation of brain death lies in visualization of the pathological changes associated with a dead brain, such as ''brain tamponade'', and the lack of enhanced contrast indicating the absence of cerebral blood flow. The latter point is still problematic as angiography revealed an extremely low cerebral blood flow in a few cases of ''dead brain'' patients. It is recommended that cerebral blood flow in brain death be evaluated by dynamic CT scanning and correlated with other methods of cerebral blood flow determination (e.g., intravenous digital subtraction angiography).

  13. CT protocol review and optimization.

    Science.gov (United States)

    Kofler, James M; Cody, Dianna D; Morin, Richard L

    2014-03-01

    To reduce the radiation dose associated with CT scans, much attention is focused on CT protocol review and improvement. In fact, annual protocol reviews will soon be required for ACR CT accreditation. A major challenge in the protocol review process is determining whether a current protocol is optimal and deciding what steps to take to improve it. In this paper, the authors describe methods for pinpointing deficiencies in CT protocols and provide a systematic approach for optimizing them. Emphasis is placed on a team approach, with a team consisting of at least one radiologist, one physicist, and one technologist. This core team completes a critical review of all aspects of a CT protocol and carefully evaluates proposed improvements. Changes to protocols are implemented only with consensus of the core team, with consideration of all aspects of the CT examination, including image quality, radiation dose, patient care and safety, and workflow.

  14. Planned FDG PET-CT Scan in Follow-Up Detects Disease Progression in Patients With Locally Advanced NSCLC Receiving Curative Chemoradiotherapy Earlier Than Standard CT

    DEFF Research Database (Denmark)

    Pan, Yi; Brink, Carsten; Schytte, Tine;

    2015-01-01

    The role of positron emission tomography-computed tomography (PET-CT) in surveillance of patients with nonsmall cell lung cancer (NSCLC) treated with curatively intended chemoradiotherapy remains controversial. However, conventional chest X-ray and computed tomography (CT) are of limited value...... in discriminating postradiotherapy changes from tumor relapse. The aim of this study was to evaluate the clinical value of PET-CT scan in the follow-up for patients with locally advanced (LA) NSCLC receiving concomitant chemoradiotherapy (CCRT).Between 2009 and 2013, eligible patients with stages IIB-IIIB NSCLC...... were enrolled in the clinical trial NARLAL and treated in Odense University Hospital (OUH). All patients had a PET-CT scan scheduled 9 months (PET-CT9) after the start of the radiation treatment in addition to standard follow-up (group A). Patients who presented with same clinical stage of NSCLC...

  15. Comparison of magnetic resonance imaging and conventional neuroradiographies in lumbar herniated nucleus pulposus

    Energy Technology Data Exchange (ETDEWEB)

    Nishijima, Yuichiro; Taniguchi, Mitsukazu; Michishita, Masamitsu; Ohta, Yoshiaki; Kondo, Takeshi; Tonami, Hisao; Yamazaki, Yasuro; Higashida, Norihiko; Yamamoto, Tatsu (Kanazawa Medical Univ., Ishikawa (Japan))

    1992-03-01

    To determine whether magnetic resonance imaging (MRI) would replace conventional neuroradiographies in lumbar herniated nucleus pulposus, preoperative MRI findings were compared with surgery-confirmed pathophysiology of 63 intervertebral disks in 58 patients. Conventional neuroradiographies consisted of myelography, CT myelography, discography, and CT discography. Pathophysiology of 63 herniated disks fall into normal (n=7), bulging (n=9), protrusion (n=14), extrusion (n=17), and free migrated (n=16). Diagnostic accuracy of MRI was evaluated in terms of the presence or absence of herniation, height, location, and morphology of herniated disk. In diagnosing herniation, MRI had a sensitivity of 96%, a specificity of 25%, and an accuracy of 78%. In determining the height of herniated disk, the diagnostic rate of MRI was 77%, being lower than both CT myelography (94%) and CT discography (89%). MRI had a concordance rate of 55% for bilateral location in transaxial view, compared with 76% for CT myelography and 74% for CT discography. MRI failed to differentiate extrusion from protrusion. In conclusion, MRI was the most suitable for screening the presence or absence of herniation; however, it was inferior to other neuroradiographies in the diagnosis of morphology of herniated disk, as well as the determination of height and surgical intervention site of herniated disk. (N.K.).

  16. Value of 3-D CT in classifying acetabular fractures during orthopedic residency training.

    Science.gov (United States)

    Garrett, Jeffrey; Halvorson, Jason; Carroll, Eben; Webb, Lawrence X

    2012-05-01

    The complex anatomy of the pelvis and acetabulum have historically made classification and interpretation of acetabular fractures difficult for orthopedic trainees. The addition of 3-dimensional (3-D) computed tomography (CT) scan has gained popularity in preoperative planning, identification, and education of acetabular fractures given their complexity. Therefore, the authors examined the value of 3-D CT compared with conventional radiography in classifying acetabular fractures at different levels of orthopedic training. Their hypothesis was that 3-D CT would improve correct identification of acetabular fractures compared with conventional radiography.The classic Letournel fracture pattern classification system was presented in quiz format to 57 orthopedic residents and 20 fellowship-trained orthopedic traumatologists. A case consisted of (1) plain radiographs and 2-dimensional axial CT scans or (2) 3-D CT scans. All levels of training showed significant improvement in classifying acetabular fractures with 3-D vs 2-D CT, with the greatest benefit from 3-D CT found in junior residents (postgraduate years 1-3).Three-dimensional CT scans can be an effective educational tool for understanding the complex spatial anatomy of the pelvis, learning acetabular fracture patterns, and correctly applying a widely accepted fracture classification system.

  17. Ultrasonography Fused with PET-CT Hybrid Imaging

    DEFF Research Database (Denmark)

    Udesen, Jesper; Ewertsen, Caroline; Gran, Fredrik

    2011-01-01

    We present a method with fusion of images of three modalities 18F-FDG PET, CT, and 3-D ultrasound (US) applied to imaging of the anal canal and the rectum. To obtain comparable geometries in the three imaging modalities, a plexiglas rod, with the same dimensions as the US transducer, is placed...... in the anal canal prior to the PET-CT examination. The method is based on manual co-registration of PET-CT images and 3-D US images. The three-modality imaging of the rectum-anal canal may become useful as a supplement to conventional imaging in the external radiation therapy in the treatment of anal cancer......, where the precise delineation of a tumor is crucial to avoid damage from radiation therapy to the healthy tissue surrounding it. The technique is still in a phase of development, and the demands for integration different company software systems are significant before commercial application. Three...

  18. CT of the base of the skull in bacterial meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Becker, H.; Schneider, E.

    1981-12-01

    CT examinations of 42 cases of bacterial meningitis revealed in 38.1% of the cases relevant inflammatory processes at the base of the skull which were of significant importance for a transmitted infection. Such infections were: Sinusitis frontalis, ethmoidalis, maxillaris and sphenoidalis, mastoiditis or petrositis, suppurating mucocele, impression fracture, and an intracranially penetrated foreign body. Excepting the identification of fine fractures, conventional X-ray films were diagnostically superior. Hence, especially in the acute stages, special projections can be omitted, if CT is effected in the region of the osseous base of the skull. CT performed in inflammatory diseases of the brain must include the base of the skull, since this will yield reliable pointers to original focus of the inflammation requiring appropriate treatment and elimination.

  19. Contribution of CT for the diagnosis of bronchial carcinoids

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, R.; Kaick, G. van; Toomes, H.

    1984-03-01

    The CT findings in 10 patients with carcinoid tumors of the lung are reported. The tumors were located in the hilar region, in the perihilar region and in the periphery of the lung. Dystelectasis and atelectasis of the lung with poststenotic inflammation were found in 4 patients. Infiltrating tumor growth with lymph node metastases were detected only once. This tumor was not able to be differentiated from other malignant space occupying lesions. There were no reliable CT criteria for bronchial carcinoids. Compared to conventional radiography the CT examination has the following advantages: better demonstration of size and location of the tumor, and the exlusion of infiltrating tumor growth, enlarged lymph nodes and calcified lung nodules.

  20. CT colonography as routine method; CT-Kolonographie in der taeglichen Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, G.; Gschwendtner, M. [Krankenhaus Elisabethinen Linz, Institut fuer Diagnostische und Interventionelle Radiologie, Linz (Austria); Mang, T. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

    2012-06-15

    Colorectal cancer is a major public health challenge in Austria and Germany. As the participation in dedicated colonoscopy screening programs is rather low, the question of alternative methods is raised again and computed tomography (CT) colonography seems to be a gentle alternative with a very high patient acceptance. In recent years CT colonography (CTC) has been established besides conventional colonoscopy as a radiological method for the investigation of the entire colon. From axial two-dimensional images three-dimensional images can be generated, allowing a virtual flight through the colon which is why this technique is also known as virtual colonoscopy. The technique of CTC has been improved continuously during recent years. On the one hand the steady decrease in the layer thickness (currently {<=} 1 mm) has improved the resolution of volume data sets and on the other hand there has been significant progress in postprocessing. Numerous studies have recently shown that the significance of CTC in the detection of advanced adenomas is similar to conventional colonoscopy. Meanwhile CT colonography is now a routine investigation method established in both symptomatic and asymptomatic patients (screening). Study data now clearly show that CTC, as an alternative to conventional colonoscopy, is a powerful method for investigation of colorectal cancer. To achieve good results adequate preparation including fecal tagging, standardized technical procedures during the investigation and expertise in both 2D and 3D reading are essential. (orig.) [German] Das kolorektale Karzinom stellt sowohl in Oesterreich wie auch in Deutschland eine grosse gesundheitspolitische Herausforderung dar. Da die Teilnahme seitens der Betroffenen an Koloskopievorsorgeprogrammen eher gering ausfaellt, wird immer wieder die Frage nach alternativen Untersuchungsmethoden aufgeworfen. Hier scheint die CT-Kolonographie eine schonende Alternative darzustellen, welche eine hohe Patientenakzeptanz