WorldWideScience

Sample records for ct arthrography-guided analysis

  1. MR appearance of cartilage defects of the knee: preliminary results of a spiral CT arthrography-guided analysis

    International Nuclear Information System (INIS)

    Berg, B.C. vande; Lecouvet, F.E.; Maldague, B.; Malghem, J.

    2004-01-01

    The aim of this study was to determine signal intensity patterns of cartilage defects at MR imaging. The MR imaging (3-mm-thick fat-suppressed intermediate-weighted fast spin-echo images) was obtained in 31 knees (21 male and 10 female patients; mean age 45.5 years) blindly selected from a series of 252 consecutive knees investigated by dual-detector spiral CT arthrography. Two radiologists determined in consensus the MR signal intensity of the cartilage areas where cartilage defects had been demonstrated on the corresponding reformatted CT arthrographic images. There were 83 cartilage defects at spiral CT arthrography. In 52 (63%) lesion areas, the MR signal intensity was higher than that of adjacent normal cartilage with signal intensity equivalent to (n=31) or lower than (n=21) that of articular fluid. The MR signal intensity was equivalent to that of adjacent normal cartilage in 17 (20%) lesion areas and lower than that of adjacent cartilage in 8 (10%) lesion areas. In 6 (7%) lesion areas, mixed low and high signal intensity was observed. The MR signal intensity of cartilage defects demonstrated on spiral CT arthrographic images varies from low to high on fat-suppressed intermediate-weighted fast spin-echo MR images obtained with our equipment and MR parameters. (orig.)

  2. Picture analysis in CT-HF and its CT photographs

    International Nuclear Information System (INIS)

    Kubota, Kazuo; Kohirasawa, Hideo; Shinojima, Masayasu; Tokui, Mitsuru; Seo, Kunihiko.

    1980-01-01

    CT (computed tomography) apparatus is rarely used yet in the field of dentistry, though it seems useful. It is possibly because of the artefacts caused by the metallic parts attached to teeth, the large partial volume effect due to many bones and the problems of positioning and reproducibility. After considering the various requirements of the CT apparatuses in dental field, CT-HF (of T/R type) was chosen as such apparatus, and installed as the first in dentistry. In the CT-HF apparatus, the inner diameter of the gantry is up to 300 mm, and the position of a tomographic plane is only 40 mm away from the front of gantry. Mainly the usefulness of scanography in positioning and the usefulness of the CT apparatus in the picture analysis and processing in dental field are described. (J.P.N.)

  3. Micro-CT and nano-CT analysis of filling quality of three different endodontic sealers.

    Science.gov (United States)

    Huang, Yan; Celikten, Berkan; de Faria Vasconcelos, Karla; Ferreira Pinheiro Nicolielo, Laura; Lippiatt, Nicholas; Buyuksungur, Arda; Jacobs, Reinhilde; Orhan, Kaan

    2017-12-01

    To investigate voids in different root canal sealers using micro-CT and nano-CT, and to explore the feasibility of using nano-CT for quantitative analysis of sealer filling quality. 30 extracted mandibular central incisors were randomly assigned into three groups according to the applied root canal sealers (Total BC Sealer, Sure Seal Root, AH Plus) by the single cone technique. Subsequently, micro-CT and nano-CT were performed to analyse the incidence rate of voids, void fraction, void volume and their distribution in each sample. Micro-CT evaluation showed no significant difference among sealers for the incidence rate of voids or void fraction in the whole filling materials (p > 0.05), whereas a significant difference was found between AH Plus and the other two sealers using nano-CT (p nano-CT results displayed higher void volume in AH Plus among all the sealers and regions (p nano-CT analysis, when round root canals were treated by the single cone technique. The disparate results suggest that the higher resolution of nano-CT have a greater ability of distinguishing internal porosity, and therefore suggesting the potential use of nano-CT in quantitative analysis of filling quality of sealers.

  4. An approach for quantitative image quality analysis for CT

    Science.gov (United States)

    Rahimi, Amir; Cochran, Joe; Mooney, Doug; Regensburger, Joe

    2016-03-01

    An objective and standardized approach to assess image quality of Compute Tomography (CT) systems is required in a wide variety of imaging processes to identify CT systems appropriate for a given application. We present an overview of the framework we have developed to help standardize and to objectively assess CT image quality for different models of CT scanners used for security applications. Within this framework, we have developed methods to quantitatively measure metrics that should correlate with feature identification, detection accuracy and precision, and image registration capabilities of CT machines and to identify strengths and weaknesses in different CT imaging technologies in transportation security. To that end we have designed, developed and constructed phantoms that allow for systematic and repeatable measurements of roughly 88 image quality metrics, representing modulation transfer function, noise equivalent quanta, noise power spectra, slice sensitivity profiles, streak artifacts, CT number uniformity, CT number consistency, object length accuracy, CT number path length consistency, and object registration. Furthermore, we have developed a sophisticated MATLAB based image analysis tool kit to analyze CT generated images of phantoms and report these metrics in a format that is standardized across the considered models of CT scanners, allowing for comparative image quality analysis within a CT model or between different CT models. In addition, we have developed a modified sparse principal component analysis (SPCA) method to generate a modified set of PCA components as compared to the standard principal component analysis (PCA) with sparse loadings in conjunction with Hotelling T2 statistical analysis method to compare, qualify, and detect faults in the tested systems.

  5. CT of hepatocellular carcinoma. Analysis of contrast-enhanced CT using CT arteriography

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H; Tanaka, T; Hori, S; Tokunaga, K; Yoshioka, H [Osaka Univ. (Japan). Faculty of Medicine

    1981-02-01

    Although changes in the CT appearance resulting from contrast enhancement (CE) for hepatocellular carcinoma have been considered in association with vascularity of tumors, no detailed studies have yet been made. We analyzed changes in the CT appearance following CE by comparing with hepatic arteriogram and CT arteriogram (CTA) performed during intraarterial infusion of contrast medium. When tumors showing low density in the plain CT were enhanced by contrast, the results were variable, ranging from intensification of the low density to replacement by high density, and the results were classified into L/sub 0/ to L/sub 3/ according to vascularity of tumors. The results after CE could also be classified into I/sub 0/ to I/sub 3/ when tumors showed isodensity in the plain CT. There was a correlation between vascularity presumed from CE and vascularity by CTA. It may be concluded that tumor vascularity could be estimated by the findings of CE which might indicate a possibility of qualitative diagnosis of tumors.

  6. CT analysis of missile head injury

    International Nuclear Information System (INIS)

    Besenski, N.; Jadro-Santel, D.; Jelavic-Koic, F.; Pavic, D.; Mikulic, D.; Glavina, K.; Maskovic, J.

    1995-01-01

    Between August 1991 and December 1992, CT was performed in 154 patients who had suffered missile head injury during the war in the Republic of Croatia. In 54% CT was performed 1-24 h after injury, and in 27% follow-up CT was also obtained. The wounds were penetrating, tangential or perforating (45%, 34% and 21%, respectively). Haemorrhage was the most frequent lesion in the brain (84%). Follow-up CT evolution of haemorrhage, oedema, cerebritis, abscess, secondary vascular lesions, necrosis, encephalomalacia and hydrocephalus. The most dynamic changes occurred 7-14 days after injury. In 14% of cases, deep cerebral lesions were found in the corpus callosum, septum pellucidum periventricular region and pons, although bone and shell fragments were in a different part of the brain parenchyma. Such lesions were found in penetrating injuries only. CT proved very useful for assessing the extent and type of lesions. Although different mechanisms of brain damage in missile head injury are known, here they are, to the best of our knowledge, shown for the first time by CT. (orig.)

  7. Comparative analysis of CT and DSA in traumatic splenic salvage

    International Nuclear Information System (INIS)

    Liu Tie; Mao Xinfeng; Pan Feng

    2005-01-01

    Objective: To explore the better diagnostic method for acute splenic artery injury through comparative analysis of CT and DSA. Methods: Fifty-seven patients with acute splenic injury were examined by CT and DSA, treated with splenic arterial embolization and then undertook follow up. Results: CT examination possessed higher sensitivity and accuracy than DSA in demonstrating splenic parenchymal laceration, intrasplenic hematoma, subcapsular hematoma, rupture of splenic capsule and combined injury of intra-abdominal organs, especially in localizing splenic laceration. And there was a high significant difference statistically between the two kinds of examination (χ 2 =10.71, P 2 =12.57, P<0.005). Conclusions: CT and DSA are complementary in the diagnosis of splenic injury. After CT confirmation of splenic injury and the patient vital signs being stable, DSA should be referred to as soon as possible for further detail information as well as for possible interventional embolization and reduction of surgical complications. (authors)

  8. Quantitative analysis of airway abnormalities in CT

    DEFF Research Database (Denmark)

    Petersen, Jens; Lo, Pechin Chien Pau; Nielsen, Mads

    2010-01-01

    A coupled surface graph cut algorithm for airway wall segmentation from Computed Tomography (CT) images is presented. Using cost functions that highlight both inner and outer wall borders, the method combines the search for both borders into one graph cut. The proposed method is evaluated on 173 ...

  9. CT analysis of pulmonary Wegener's granulomatosis

    International Nuclear Information System (INIS)

    Liao Hualing; Chen Jianbo; Zhong Wenchen; Chen Jingdi

    2010-01-01

    Objective: To study the CT features and to improve the diagnostic accuracy of pulmonary Wegener's granulomatosis. Methods: 11 patients with histopathologically and clinically proven Wegener's granulomatosis were included in the study. Chest radiography was performed in all 11 patients and 8 patients underwent chest CT. Results: Lung abnormalities were noted in 10/11 patients including patchy lung opacities (n=3), multiple nodules (less than 3 cm in diameter, n=4), masses (more than 3cm in diameter, n=3), and cavitations (n=8). Multiple findings were observed in 4 patients. Conclusion: Imaging manifestations of pulmonary Wegener's granulomatosis were variable. Patchy lung opacities, nodules and cavitation were most common. Thin-walled cavity and ring-shaped cavity were characteristic. Pneumonia, abscess, tuberculosis and carcinoma should be included in the differential diagnosis. (authors)

  10. Juvenile spondylolysis: a comparative analysis of CT, SPECT and MRI

    International Nuclear Information System (INIS)

    Campbell, R.S.D.; Grainger, A.J.; Hide, I.G.; Papastefanou, S.; Greenough, C.G.

    2005-01-01

    To evaluate whether MRI correlates with CT and SPECT imaging for the diagnosis of juvenile spondylolysis, and to determine whether MRI can be used as an exclusive image modality. Juveniles and young adults with a history of extension low back pain were evaluated by MRI, CT and SPECT imaging. All images were reviewed blindly. Correlative analyses included CT vs MRI for morphological grading and SPECT vs MRI for functional grading. Finally, an overall grading system compared MRI vs CT and SPECT combined. Statistical analysis was performed using the kappa statistic. Seventy-two patients (mean age 16 years) were recruited. Forty pars defects were identified in 22 patients (31%), of which 25 were chronic non-union, five acute complete defects and ten acute incomplete fractures. Kappa scores demonstrated a high level of agreement for all comparative analyses. MRI vs SPECT (kappa: 0.794), MRI vs CT (kappa: 0.829) and MRI vs CT/SPECT (kappa: 0.786). The main causes of discrepancy were between MRI and SPECT for the diagnosis of stress reaction in the absence of overt fracture, and distinguishing incomplete fractures from intact pars or complete defects. MRI can be used as an effective and reliable first-line image modality for diagnosis of juvenile spondylolysis. However, localised CT is recommended as a supplementary examination in selected cases as a baseline for assessment of healing and for evaluation of indeterminate cases. (orig.)

  11. Juvenile spondylolysis: a comparative analysis of CT, SPECT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R.S.D. [Royal Liverpool University Hospital, Department of Radiology, Liverpool (United Kingdom); Grainger, A.J. [Leeds General Infirmary, Department of Radiology, Leeds (United Kingdom); Hide, I.G. [Freeman Hospital, Department of Radiology, Newcastle upon Tyne (United Kingdom); Papastefanou, S. [James Cook University Hospital, Department Radiology, Middlesbrough (United Kingdom); Greenough, C.G. [James Cook University Hospital, Department of Trauma and Orthopaedics, Middlesbrough (United Kingdom)

    2005-02-01

    To evaluate whether MRI correlates with CT and SPECT imaging for the diagnosis of juvenile spondylolysis, and to determine whether MRI can be used as an exclusive image modality. Juveniles and young adults with a history of extension low back pain were evaluated by MRI, CT and SPECT imaging. All images were reviewed blindly. Correlative analyses included CT vs MRI for morphological grading and SPECT vs MRI for functional grading. Finally, an overall grading system compared MRI vs CT and SPECT combined. Statistical analysis was performed using the kappa statistic. Seventy-two patients (mean age 16 years) were recruited. Forty pars defects were identified in 22 patients (31%), of which 25 were chronic non-union, five acute complete defects and ten acute incomplete fractures. Kappa scores demonstrated a high level of agreement for all comparative analyses. MRI vs SPECT (kappa: 0.794), MRI vs CT (kappa: 0.829) and MRI vs CT/SPECT (kappa: 0.786). The main causes of discrepancy were between MRI and SPECT for the diagnosis of stress reaction in the absence of overt fracture, and distinguishing incomplete fractures from intact pars or complete defects. MRI can be used as an effective and reliable first-line image modality for diagnosis of juvenile spondylolysis. However, localised CT is recommended as a supplementary examination in selected cases as a baseline for assessment of healing and for evaluation of indeterminate cases. (orig.)

  12. 3D CT versus axial helical CT versus conventional tomography in the classification of acetabular fractures: A ROC analysis

    International Nuclear Information System (INIS)

    Kickuth, Ralph; Laufer, Ulf; Hartung, Guido; Gruening, Christian; Stueckle, Christoph; Kirchner, Johannes

    2002-01-01

    AIM: To assess the diagnostic power of three-dimensional computed tomography (3D CT), axial helical computed tomography (CT) and conventional tomography in the classification of acetabular fractures by interdisciplinary review. MATERIALS AND METHODS: Receiver operating characteristics (ROCs) were assessed for two radiologists and two surgeons blinded to the presence of acetabular fractures in an animal model (a total of 62 porcine hips, 40 of them with artificial acetabular fractures). Main target parameter was the diagnostic accuracy in the classification of the artificial fractures following Judet et al. RESULTS: ROC analysis for radiologists showed A z values of 0·83 for 3D CT, 0·81 for axial helical CT, and 0·78 for conventional tomography; differences between the three techniques were not significant (P = 0·46-0·73). A z values for the surgeons were 0·87 for 3D CT, 0·68 for axial helical CT, and 0·60 for conventional tomography; 3D CT was significantly better than axial helical CT (P = 0·01) and conventional tomography (P = 0·001). The differences between axial helical CT and conventional tomography were not significant (P = 0·37). CONCLUSION: Acetabular fractures are best classified by 3D CT, followed by axial helical CT and conventional tomography when assessed by surgeons. 3D CT did not provide any additional significant benefit in the classification performed by radiologists. Kickuth, R. et al. (2002)

  13. Reliability and error analysis on xenon/CT CBF

    International Nuclear Information System (INIS)

    Zhang, Z.

    2000-01-01

    This article provides a quantitative error analysis of a simulation model of xenon/CT CBF in order to investigate the behavior and effect of different types of errors such as CT noise, motion artifacts, lower percentage of xenon supply, lower tissue enhancements, etc. A mathematical model is built to simulate these errors. By adjusting the initial parameters of the simulation model, we can scale the Gaussian noise, control the percentage of xenon supply, and change the tissue enhancement with different kVp settings. The motion artifact will be treated separately by geometrically shifting the sequential CT images. The input function is chosen from an end-tidal xenon curve of a practical study. Four kinds of cerebral blood flow, 10, 20, 50, and 80 cc/100 g/min, are examined under different error environments and the corresponding CT images are generated following the currently popular timing protocol. The simulated studies will be fed to a regular xenon/CT CBF system for calculation and evaluation. A quantitative comparison is given to reveal the behavior and effect of individual error resources. Mixed error testing is also provided to inspect the combination effect of errors. The experiment shows that CT noise is still a major error resource. The motion artifact affects the CBF results more geometrically than quantitatively. Lower xenon supply has a lesser effect on the results, but will reduce the signal/noise ratio. The lower xenon enhancement will lower the flow values in all areas of brain. (author)

  14. Quantitative CT analysis of small pulmonary vessels in lymphangioleiomyomatosis

    International Nuclear Information System (INIS)

    Ando, Katsutoshi; Tobino, Kazunori; Kurihara, Masatoshi; Kataoka, Hideyuki; Doi, Tokuhide; Hoshika, Yoshito; Takahashi, Kazuhisa; Seyama, Kuniaki

    2012-01-01

    Backgrounds: Lymphangioleiomyomatosis (LAM) is a destructive lung disease that share clinical, physiologic, and radiologic features with chronic obstructive pulmonary disease (COPD). This study aims to identify those features that are unique to LAM by using quantitative CT analysis. Methods: We measured total cross-sectional areas of small pulmonary vessels (CSA) less than 5 mm 2 and 5–10 mm 2 and calculated percentages of those lung areas (%CSA), respectively, in 50 LAM and 42 COPD patients. The extent of cystic destruction (LAA%) and mean parenchymal CT value were also calculated and correlated with pulmonary function. Results: The diffusing capacity for carbon monoxide/alveolar volume (DL CO /VA %predicted) was similar for both groups (LAM, 44.4 ± 19.8% vs. COPD, 45.7 ± 16.0%, p = 0.763), but less tissue damage occurred in LAM than COPD (LAA% 21.7 ± 16.3% vs. 29.3 ± 17.0; p CO /VA %predicted, %CSA and mean parenchymal CT value were still greater for LAM than COPD (p < 0.05). Conclusions: Quantitative CT analysis revealing a correlation between cystic destruction and CSA in COPD but not LAM indicates that this approach successfully reflects different mechanisms governing the two pathologic courses. Such determinations of small pulmonary vessel density may serve to differentiate LAM from COPD even in patients with severe lung destruction.

  15. Quantification analysis of CT for aphasic patients

    International Nuclear Information System (INIS)

    Watanabe, Shunzo; Ooyama, Hiroshi; Hojo, Kei; Tasaki, Hiroichi; Hanazono, Toshihide; Sato, Tokijiro; Metoki, Hirobumi; Totsuka, Motokichi; Oosumi, Noboru.

    1987-01-01

    Using a microcomputer, the locus and extent of the lesions, as demonstrated by computed tomography, for 44 aphasic patients with various types of aphasia were superimposed onto standardized matrices, composed of 10 slices with 3000 points (50 by 60). The relationships between the foci of the lesions and types of aphasia were investigated on the slices numbered 3, 4, 5, and 6 using a quantification theory, Type 3 (pattern analysis). Some types of regularities were observed on Slices 3, 4, 5, and 6. The group of patients with Broca's aphasia and the group with Wernicke's aphasia were generally separated on the 1st component and the 2nd component of the quantification theory, Type 3. On the other hand, the group with global aphasia existed between the group with Broca's aphasia and that with Wernicke's aphasia. The group of patients with amnestic aphasia had no specific findings, and the group with conduction aphasia existed near those with Wernicke's aphasia. The above results serve to establish the quantification theory, Type 2 (discrimination analysis) and the quantification theory, Type 1 (regression analysis). (author)

  16. Quantification analysis of CT for aphasic patients

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, S.; Ooyama, H.; Hojo, K.; Tasaki, H.; Hanazono, T.; Sato, T.; Metoki, H.; Totsuka, M.; Oosumi, N.

    1987-02-01

    Using a microcomputer, the locus and extent of the lesions, as demonstrated by computed tomography, for 44 aphasic patients with various types of aphasia were superimposed onto standardized matrices, composed of 10 slices with 3000 points (50 by 60). The relationships between the foci of the lesions and types of aphasia were investigated on the slices numbered 3, 4, 5, and 6 using a quantification theory, Type 3 (pattern analysis). Some types of regularities were observed on slices 3, 4, 5, and 6. The group of patients with Broca's aphasia and the group with Wernicke's aphasia were generally separated on the 1st component and the 2nd component of the quantification theory, Type 3. On the other hand, the group with global aphasia existed between the group with Broca's aphasia and that with Wernicke's aphasia. The group of patients with amnestic aphasia had no specific findings, and the group with conduction aphasia existed near those with Wernicke's aphasia. The above results serve to establish the quantification theory, Type 2 (discrimination analysis) and the quantification theory, Type 1 (regression analysis).

  17. Analysis on CT features of tumor-like gastric schwannomas

    International Nuclear Information System (INIS)

    Zhang Yu; Chen Jie

    2011-01-01

    Objective: To analyze CT imaging features of tumor-like gastric schwannomas. Methods: Ten patients with gastric schwannomas were retrospectively analyzed. All were scanned with pre-and pro-enhanced CT. Analysis of the CT findings included evaluation of the volume, number, location, contour, growth pattern, border, enhancement pattern, and enhancement grade as well as the presence of surface dimpling, integrity of overlying mucosa. All cases were confirmed by pathology. Results: In every case, simple tumor was present. The largest was about 5.7 cm in the diameter, the smallest was 2.3 cm. All tumors were round or oval, and one tumor was slightly lobulated. Endoluminal growth pattern was defined in two cases, exoluminal growth pattern was defined in one case, and a mixed growth pattern was noted in the rest. The borders of tumors were clear. In arterial phase, no visible enhancement was present in eight cases and mild enhancement in two cases. All cases were constantly enhanced in portal phase. Superficial ulcers were present in four cases. Conclusion: CT findings of tumor-like gastric schwannomas are distinctive to a certain degree. It can be used to guide clinical therapy. (authors)

  18. Daily quality controls analysis of a CT scanner simulator

    International Nuclear Information System (INIS)

    Vasques, Maira Milanelo; Santos, Gabriela R.; Furnari, Laura

    2016-01-01

    With the increasing technological developments, radiotherapy practices, which allow for better involvement of the tumor with the required therapeutic dose and minimize the complications of normal tissues, have become reality in several Radiotherapy services. The use of these resources in turn, was only possible due to the progress made in planning based on digital volumetric images of good quality, such as computed tomography (CT), which allow the correct delimitation of the tumor volume and critical structures. Specific tests for quality control in a CT scanner used in radiotherapy, named CT simulator, should be applied as part of the institutional Quality Assurance Program. This study presents the methodology used in the Instituto de Radiologia do Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (HCFMUSP) for daily testing of the CT scanner simulator and the results obtained throughout more than two years. The experience gained in the period conducted showed that the tests are easy to perform and can be done in a few minutes by a trained professional. Data analysis showed good reproducibility, which allowed the tests could be performed less frequently, after 16 months of data collection. (author)

  19. Quantitative CT analysis of small pulmonary vessels in lymphangioleiomyomatosis

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Katsutoshi, E-mail: kando@juntendo.ac.jp [Department of Internal Medicine, Division of Respiratory Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); Tobino, Kazunori [Department of Respiratory Medicine, Iizuka Hospital, 3-83 Yoshio-Machi, Iizuka-City, Fukuoka 820-8505 (Japan); The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); Kurihara, Masatoshi; Kataoka, Hideyuki [Pneumothorax Center, Nissan Tamagawa Hospital, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); Doi, Tokuhide [Fukuoka Clinic, 7-18-11 Umeda, Adachi-Ku, Tokyo 123-0851 (Japan); Hoshika, Yoshito [Department of Internal Medicine, Division of Respiratory Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); Takahashi, Kazuhisa [Department of Internal Medicine, Division of Respiratory Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); Seyama, Kuniaki [Department of Internal Medicine, Division of Respiratory Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan)

    2012-12-15

    Backgrounds: Lymphangioleiomyomatosis (LAM) is a destructive lung disease that share clinical, physiologic, and radiologic features with chronic obstructive pulmonary disease (COPD). This study aims to identify those features that are unique to LAM by using quantitative CT analysis. Methods: We measured total cross-sectional areas of small pulmonary vessels (CSA) less than 5 mm{sup 2} and 5–10 mm{sup 2} and calculated percentages of those lung areas (%CSA), respectively, in 50 LAM and 42 COPD patients. The extent of cystic destruction (LAA%) and mean parenchymal CT value were also calculated and correlated with pulmonary function. Results: The diffusing capacity for carbon monoxide/alveolar volume (DL{sub CO}/VA %predicted) was similar for both groups (LAM, 44.4 ± 19.8% vs. COPD, 45.7 ± 16.0%, p = 0.763), but less tissue damage occurred in LAM than COPD (LAA% 21.7 ± 16.3% vs. 29.3 ± 17.0; p < 0.05). Pulmonary function correlated negatively with LAA% (p < 0.001) in both groups, yet the correlation with %CSA was significant only in COPD (p < 0.001). When the same analysis was conducted in two groups with equal levels of LAA% and DL{sub CO}/VA %predicted, %CSA and mean parenchymal CT value were still greater for LAM than COPD (p < 0.05). Conclusions: Quantitative CT analysis revealing a correlation between cystic destruction and CSA in COPD but not LAM indicates that this approach successfully reflects different mechanisms governing the two pathologic courses. Such determinations of small pulmonary vessel density may serve to differentiate LAM from COPD even in patients with severe lung destruction.

  20. Role of CT in the Diagnosis of Nonspecific Abdominal Pain: A Multicenter Analysis.

    Science.gov (United States)

    Eisenberg, Jonathan D; Reisner, Andrew T; Binder, William D; Zaheer, Atif; Gunn, Martin L; Linnau, Ken F; Miller, Chad M; Tramontano, Angela C; Herring, Maurice S; Dowling, Emily C; Halpern, Elkan F; Donelan, Karen; Gazelle, G Scott; Pandharipande, Pari V

    2017-03-01

    The objective of our study was to determine whether specific patient and physician factors-known before CT-are associated with a diagnosis of nonspecific abdominal pain (NSAP) after CT in the emergency department (ED). We analyzed data originally collected in a prospective multicenter study. In the parent study, we identified ED patients referred to CT for evaluation of abdominal pain. We surveyed their physicians before and after CT to identify changes in leading diagnoses, diagnostic confidence, and admission decisions. In the current study, we conducted a multiple regression analysis to identify whether the following were associated with a post-CT diagnosis of NSAP: patient age; patient sex; physicians' years of experience; physicians' pre-CT diagnostic confidence; and physicians' pre-CT admission decision if CT had not been available. We analyzed patients with and those without a pre-CT diagnosis of NSAP separately. For the sensitivity analysis, we excluded patients with different physicians before and after CT. In total, 544 patients were included: 10% (52/544) with a pre-CT diagnosis of NSAP and 90% (492/544) with a pre-CT diagnosis other than NSAP. The leading diagnoses changed after CT in a large proportion of patients with a pre-CT diagnosis of NSAP (38%, 20/52). In regression analysis, we found that physicians' pre-CT diagnostic confidence was inversely associated with a post-CT diagnosis of NSAP in patients with a pre-CT diagnosis other than NSAP (p = 0.0001). No other associations were significant in both primary and sensitivity analyses. With the exception of physicians' pre-CT diagnostic confidence, the factors evaluated were not associated with a post-CT diagnosis of NSAP.

  1. Clinical study on primary epilepsy by computerized analysis of CT

    International Nuclear Information System (INIS)

    Tominaga, Hidefumi; Ueyama, Kenichi; Mizutani, Hiroshi; Imamura, Keisuke; Yoshidome, Kazushi; Matsumoto, Kei

    1985-01-01

    CT scans were examined by conventional linear measurement method and computerized analysis in 17 patients with primary epilepsy (Group A). Results were compared with those in healthy volunteers (Group B). Relationship between CT and EEG findings was also examined. The maximum width of the third cerebral ventricle (TCV) was narrowed in Group A than in Group B, with statistically significant difference. Low density rates (LDR) in Group A tended to be lower than those in Group B. There was significant difference in narrowed maximum width of TCV between Group A presenting with sudden dysrhythmia and Group B. For this type of Group A, LDR was significantly lower than that for Group B. These results suggest some changes in the brain in young epilepsy patients, especially those presenting with sudden dysrhythemia. (Namekawa, K.)

  2. Comparative analysis of multi-slice spiral CT and positron emission tomography-CT in evaluation of axillary lymph nodes in breast cancer patients

    International Nuclear Information System (INIS)

    Sun Xianchang; Zhang Ruyi; Liu Qingwei; Zhao Suhong; Zu Degui; Li Xin

    2008-01-01

    Objective: To evaluate and compare spiral CT and positron emission tomography-CT (PET-CT) in characterization of of axillary lymph nodes in breast cancer patients. Methods: Forty patients with pathologically proven breast cancer underwent contrast-enhanced spiral CT of the breast and axilla, 13 of them also underwent PET-CT examination. One hundred and fifty-eight axillary lymph nodes were found in the 40 patients through contrast enhanced spiral CT, while 57 lymph nodes were found in the 13 patients through PET-CT. Three radiologists rated the lymph nodes found in CT images on a five-point scale. If the score was equal to or greater than 3, it was defined as positive (metastatic), otherwise negative. Visual observation and semiquantitative analysis were used to classify lymph nodes in PET-CT images. The results of spiral CT observation and PET-CT observation of lymph nodes were compared with pathological results. The relative value of CT and PET-CT was analyzed. Exact probability statistics were employed. Results: One hundred and fifty eight lymph nodes of 40 patients were detected by spiral CT, 91 of them were diagnosed as positive and 67 as negative Among the lymph nodes found in spiral CT, 99 were positive and 59 were negative pathologicall. A total of 57 lymph nodes were found by PET-CT. Thirty-nine of them were defined as positive and 18 as negative. Among the lymph nodes found in PET-CT, 39 were positive and 18 were negative pathologically. The sensitivity, specificity, accuracy, positive and negative predictive values in CT prediction in axillary lymph nodes metastases were 88.89%, 94.91%, 91.14%, 96.70%, and 83.58%, respectively. The sensitivity, specificity, accuracy, positive and negative predictive values in PET-CT prediction in axillary lymph nodes metastases were 97.44%, 94.44%, 96.49%, 97.44%, and 94.44%, respectively. PET-CT had no significant difference with spiral CT in sensitivity, accuracy, positive and negative predictive values for detection

  3. Anorexia Nervosa: Analysis of Trabecular Texture with CT.

    Science.gov (United States)

    Tabari, Azadeh; Torriani, Martin; Miller, Karen K; Klibanski, Anne; Kalra, Mannudeep K; Bredella, Miriam A

    2017-04-01

    Purpose To determine indexes of skeletal integrity by using computed tomographic (CT) trabecular texture analysis of the lumbar spine in patients with anorexia nervosa and normal-weight control subjects and to determine body composition predictors of trabecular texture. Materials and Methods This cross-sectional study was approved by the institutional review board and compliant with HIPAA. Written informed consent was obtained. The study included 30 women with anorexia nervosa (mean age ± standard deviation, 26 years ± 6) and 30 normal-weight age-matched women (control group). All participants underwent low-dose single-section quantitative CT of the L4 vertebral body with use of a calibration phantom. Trabecular texture analysis was performed by using software. Skewness (asymmetry of gray-level pixel distribution), kurtosis (pointiness of pixel distribution), entropy (inhomogeneity of pixel distribution), and mean value of positive pixels (MPP) were assessed. Bone mineral density and abdominal fat and paraspinal muscle areas were quantified with quantitative CT. Women with anorexia nervosa and normal-weight control subjects were compared by using the Student t test. Linear regression analyses were performed to determine associations between trabecular texture and body composition. Results Women with anorexia nervosa had higher skewness and kurtosis, lower MPP (P anorexia nervosa. Conclusion Patients with anorexia nervosa had increased skewness and kurtosis and decreased entropy and MPP compared with normal-weight control subjects. These parameters were associated with lowest lifetime weight and duration of amenorrhea, but there were no such associations with bone mineral density. These findings suggest that trabecular texture analysis might contribute information about bone health in anorexia nervosa that is independent of that provided with bone mineral density. © RSNA, 2016.

  4. X-ray CT analysis on archaeological iron based artifacts

    International Nuclear Information System (INIS)

    Honda, Takashi; Gunji, Eiichi

    2005-01-01

    Corrosion analysis was carried out on twenty iron-plates, which had been dug out at the 6th Yamato ancient tomb (Nara-shi). It was evaluated through the inner-structural analysis by X-ray CT and the XRD and chemical analysis of the rusts that the most iron-plates had been buried in a slightly oxidizing environment and the maximum corrosion depth was 1.6 mm for about 1500 years. The analysis result of the extreme-value data indicates that the maximum depth of an overpack is estimated to be 2.5-2.7 mm. A part of small iron-plates were supposed to have been buried in an oxidizing environment, and about 1 mm-thick rust layers with cavities existed and the corrosion amount was figured out to be about 0.3 mm. (author)

  5. CT interpretation of craniofacial anomalies: a comparative analysis by undergraduate dental students

    International Nuclear Information System (INIS)

    Gaia, Bruno Felipe; Perella, Andreia; Cara, Ana Claudia Ballet de; Antunes, Jose Leopoldo Ferreira; Cavalcanti, Marcelo Gusmao Paraiso

    2005-01-01

    The aim of this study was to evaluate the accuracy and reproducibility of computed tomography (CT) image interpretation made in axial slices (2D-CT) and 3D reconstructed images (3D-CT) of patients with craniofacial anomalies. The analyses were made by undergraduate dental students, and compared with the diagnoses considered upon surgical intervention. Computed tomography of 43 patients were analyzed independently by three calibrated examiners (undergraduate students) with, respectively, one, two, and three semesters of experience in craniofacial CT training and interpretation. The analysis of 2D-CT and 3D-CT images were performed at distinct times using an independent workstation associated with a specific computer graphics software for volumetric images. The analysis of inter-examiner agreement and of the agreement between observers and the gold standard was performed using the Kappa test. The accuracy evaluation presented a progressively higher value for examiners with progressively broader experience in 2D-CT and 3D-CT image interpretation. 3D-CT analyses allowed a higher inter-examiner agreement (1 - 0.896) than 2D-CT analyses (1 - 0.614). 3D-CT was considered more precise and accurate than 2D-CT for all students' evaluations. The reproducibility and accuracy varied according to the experience in CT interpretation, and the most experienced student achieved results closer to the gold standard. (author)

  6. PET/CT and contrast enhanced CT in single vs. two separate sessions: a cost analysis study.

    Science.gov (United States)

    Picchio, M; Mansueto, M; Crivellaro, C; Guerra, L; Marcelli, S; Arosio, M; Sironi, S; Gianolli, L; Grimaldi, A; Messa, C

    2012-06-01

    Aim of the study was to quantify the economic impact of PET/CT and contrast enhanced (c.e.) CT performed in a single session examination vs. stand-alone modalities in oncological patients. One-hundred-forty-five cancer patients referred to both PET/CT and c.e. CT, to either stage (N.=46) or re-stage (N.=99) the disease, were included. Seventy-two/145 performed both studies in a single session (innovative method) and 73/145 in two different sessions (traditional method). The cost-minimization analysis was performed by evaluating: 1) institutional costs, data obtained by hospital accountability (staff, medical materials, equipment maintenance and depreciation, departments utilities); 2) patients costs, data obtained by a specific survey provided to patients (travel, food, accommodation costs, productivity loss). Economic data analysis showed that the costs for innovative method was lower than those of traditional method, both for Institution (106 € less per test) and for patient (21 € less per patient). The loss of productivity for patient and caregivers resulted lower for the innovative method than the traditional method (3 work-hour less per person). PET/CT and c.e. CT performed in a single session is more cost-effective than stand-alone modalities, by reducing both Institutional and patients costs. These advantages are mainly due to lower Institutional cost (single procedure) and to lower cost related to travel and housing.

  7. Pulmonary infections after kidney transplantation: analysis of CT findings

    International Nuclear Information System (INIS)

    Xue Feng; Liu Shiyuan; Li Li; Gao Xin; Liu Kai; Li Huimin

    2009-01-01

    Objective: To review the CT findings in patients with pulmonary infection after kidney transplantation and to determine the characteristic features in different infections. Methods: The medical records were reviewed in 446 patients with pulmonary infection after kidney transplantation and 121 patients who had pulmonary thin-section CT were included in this study. The pattern and distribution of the pulmonary abnormalities were interpreted independently by two thoracic radiologists. Statistical analysis was performed using the χ 2 test and the Fisher's exact test. Results: (1) Time course: 65 (14.6%) patients initially had pulmonary infection in the first 30 days, 147 (32.9%) between 1 and 3 months, 91 (20.4%) between 3 and 6 months, 23 (5.2%) between 6 and 12 months, 120 (26.9%)after 12 months of transplantation. In the first month after procedure, bacterial infection (4/5,80.0%) was the most common infection, bacterial (34/41,82.9%), mixed (19/41,46.3%) and vires infections (11/41,26.8%) were seen commonly 1 to 6 months following transplant, the incidence of fungal (14/38, 36.8%) and mycobacterial (5/38,13.2%) infections was increased after 12 months of transplantation. (2)Pathogens: Bacterial (34,28%) and mixed infections (34,28%) were the most common, followed by fungus infection (9, 7%), TB(7,6%)and cytomegalovims (5,4%). (3)CT findings: Ground-glass attenuations (69,57.0%) was the most common findings of pneumonia, followed by reticular or linear opacities (68,56.2%), nodules (66,54.5%), pleural thickening (41,33.9%), consolidations (31,25.6%), tree-in-bud patterns (24, 19.8%), pleural effusion (22,18.2%), and bronchovascular bundle thickening (16,13.2%). Ground-glass attenuation was commonly seen in cytomegalovims pneumonia (4,80.0%), and nodule was commonly observed in bacterial infection (23,67.6%), tree-in-bud pattern was the most common finding in pulmonary tuberculosis(4, P=0.049). There were no statistically significant differences in the prevalence of

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

    Science.gov (United States)

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

    2016-06-01

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

  9. An analysis of CT findings of mediastinal lymphadenopathy

    International Nuclear Information System (INIS)

    Park, Jeong Mi; Im, Jung Gi; Hong, Ju Hee; Han, Man Chung

    1988-01-01

    CT plays an important role in evaluating mediastinal lymphadenopathy, especially in the staging of lung cancer. However, its role has been confined to the detectability of pathologic lymph nodes by using the size criteria. Still seldom effort has been made on morphologic analysis of the diseased lymph nodes. We analyzed post-enhance CT scans of 64 pathologically proven patients who had mediastinal lymphadenopathy, with special reference to nodal architecture. 24 of the 41 patients with lung cancer and 15 of the 17 patients with tuberculous mediastinal lymphadenitis showed intranodal necrotic low density. Not only tuberculous lymph nodes showed higher incidence but also showed higher conspicuity of the necrotic low density than that of the metastatic nodes from lung cancer. Conspicuity of internal low density in tuberculous nodes was due to significantly higher density of enhanced rim (121.7±18.7 HU) than that of metastatic nodes (91.2±23.4 HU) (P<0.01). As the node size increases incidences of necrotic low density increased both in tuberculous and metastatic nodes, but the latter steeper. Analysis of the location of the diseased node did not show any significant difference between tuberculous and metastatic nodes. If there is coexistence of primary lung mass, the possibility of lung cancer was markedly elevated than that of tuberculosis and the internal low density in lung mass shows some tendency of coexistence of central low density within metastatic lymph nodes.

  10. Serial automated quantitative CT analysis in idiopathic pulmonary fibrosis. Functional correlations and comparison with changes in visual CT scores

    International Nuclear Information System (INIS)

    Jacob, Joseph; Bartholmai, Brian J.; Rajagopalan, Srinivasan; Kokosi, Maria; Wells, Athol U.; Egashira, Ryoko; Brun, Anne Laure; Nair, Arjun; Walsh, Simon L.F.; Karwoski, Ronald

    2018-01-01

    To determine whether computer-based CT quantitation of change can improve on visual change quantification of parenchymal features in IPF. Sixty-six IPF patients with serial CT imaging (6-24 months apart) had CT features scored visually and with a computer software tool: ground glass opacity, reticulation and honeycombing (all three variables summed as interstitial lung disease extent [ILD]) and emphysema. Pulmonary vessel volume (PVV) was estimated by computer only. Relationships between changes in CT features and forced vital capacity (FVC) were examined using univariate and multivariate linear regression analyses. On univariate analysis, changes in computer variables demonstrated stronger linkages to FVC change than changes in visual scores (CALIPER ILD:R 2 =0.53, p<0.0001; Visual ILD:R 2 =0.16, p=0.001). PVV increase correlated most strongly with relative FVC change (R 2 =0.57). When PVV constituents (vessel size and location) were examined, an increase in middle zone vessels linked most strongly to FVC decline (R 2 =0.57) and was independent of baseline disease severity (characterised by CT fibrosis extent, FVC, or DLco). An increase in PVV, specifically an increase in middle zone lung vessels, was the strongest CT determinant of FVC decline in IPF and was independent of baseline disease severity. (orig.)

  11. Serial automated quantitative CT analysis in idiopathic pulmonary fibrosis. Functional correlations and comparison with changes in visual CT scores

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Joseph; Bartholmai, Brian J.; Rajagopalan, Srinivasan [Mayo Clinic Rochester, Division of Radiology, Rochester, MN (United States); Kokosi, Maria; Wells, Athol U. [Royal Brompton and Harefield NHS Foundation Trust, Interstitial Lung Disease Unit, Royal Brompton Hospital, London (United Kingdom); Egashira, Ryoko [Saga Daigaku, Department of Radiology, Saga (Japan); Brun, Anne Laure [Whittington Hospital, Department of Radiology, London (United Kingdom); Nair, Arjun [Guys and St Thomas' NHS Foundation Trust, Department of Radiology, London (United Kingdom); Walsh, Simon L.F. [Kings College Hospital NHS Foundation Trust, Department of Radiology, London (United Kingdom); Karwoski, Ronald [Mayo Clinic Rochester, Department of Physiology and Biomedical Engineering, Rochester, MN (United States)

    2018-03-15

    To determine whether computer-based CT quantitation of change can improve on visual change quantification of parenchymal features in IPF. Sixty-six IPF patients with serial CT imaging (6-24 months apart) had CT features scored visually and with a computer software tool: ground glass opacity, reticulation and honeycombing (all three variables summed as interstitial lung disease extent [ILD]) and emphysema. Pulmonary vessel volume (PVV) was estimated by computer only. Relationships between changes in CT features and forced vital capacity (FVC) were examined using univariate and multivariate linear regression analyses. On univariate analysis, changes in computer variables demonstrated stronger linkages to FVC change than changes in visual scores (CALIPER ILD:R{sup 2}=0.53, p<0.0001; Visual ILD:R{sup 2}=0.16, p=0.001). PVV increase correlated most strongly with relative FVC change (R{sup 2}=0.57). When PVV constituents (vessel size and location) were examined, an increase in middle zone vessels linked most strongly to FVC decline (R{sup 2}=0.57) and was independent of baseline disease severity (characterised by CT fibrosis extent, FVC, or DLco). An increase in PVV, specifically an increase in middle zone lung vessels, was the strongest CT determinant of FVC decline in IPF and was independent of baseline disease severity. (orig.)

  12. Two- and three-dimensional CT analysis of ankle fractures

    International Nuclear Information System (INIS)

    Magid, D.; Fishman, E.K.; Ney, D.R.; Kuhlman, J.E.

    1988-01-01

    CT with coronal and sagittal reformatting (two-dimensional CT) and animated volumetric image rendering (three-dimensional CT) was used to assess ankle fractures. Partial volume limits transaxial CT in assessments of horizontally oriented structures. Two-dimensional CT, being orthogonal to the plafond, superior mortise, talar dome, and tibial epiphysis, often provides the most clinically useful images. Two-dimensional CT is most useful in characterizing potentially confusing fractures, such as Tillaux (anterior tubercle), triplane, osteochondral talar dome, or nondisplaced talar neck fractures, and it is the best study to confirm intraarticular fragments. Two-and three-dimensional CT best indicate the percentage of articular surface involvement and best demonstrate postoperative results or complications (hardware migration, residual step-off, delayed union, DJD, AVN, etc). Animated three-dimensional images are the preferred means of integrating the two-dimensional findings for surgical planning, as these images more closely simulate the clinical problem

  13. Analysis of brain CT on 120 patients of human cysticercosis

    International Nuclear Information System (INIS)

    Ma, J.; To, R.; Ri, T.; Ra, S.; Inomata, Taiten; Ogawa, Yasuhiro; Maeda, Tomoo.

    1990-01-01

    A study on brain CT was made in 120 patients of human cysticercosis, which is a rare disease in Japan and clinical symptoms and laboratory data for the diagnosis were also discussed. From the point of therapeutic view, we proposed a new differentiation on brain CT of human cysticercosis, which is divided into two groups according to the alve or dead parasite. Furthermore, we proposed a new type named multiple large and small cysts type on brain CT. The idea of diagnostic standard was made integrating brain CT image, clinical symptoms and labolatory data. (author)

  14. CT analysis of pulmonary injuries from blunt chest trauma

    International Nuclear Information System (INIS)

    Konno, Shoko

    1996-01-01

    The purpose of this paper is to analyze the CT findings of pulmonary parenchymal injuries due to blunt chest trauma and to categorize CT findings on the basis of their outcome. The materials of this study consist of 62 patients who had pulmonary injuries on CT obtained within 6 hours after blunt chest trauma. CT findings were analysed with regards to the shape, size, and distribution of the lesions. Follow-up CT scans were obtained in 35 patients at intervals from 1 day to 1 month after the initial CT study. CT showed ill-defined opacities in 59 patients (64 lesions in the peripheral area and 95 in the non-peripheral area) and pulmonary nodules with or without cavitary lesions in 30 patients (7 lesions in the peripheral area and 31 in the non-peripheral area). Follow-up CT allowed the classification of these pulmonary injuries into 3 types; the non-peripheral, ill-defined opacities showing immediate clearing, nodules with or without cavitary lesions over 1 cm in diameter showing prolongation, and the peripheral ill-defined opacities adjacent to the thoracic cage, and small nodules with or without cavitary lesions within 1 cm in diameter, showing various courses. CT has marked advantage over plain chest radiographs not only in the detection rate but in accurate estimation of the prognosis of the lesions. (author)

  15. CT analysis of metastatic neoplasms of the kidney

    International Nuclear Information System (INIS)

    Honda, H.; Coffman, C.E.; Berbaum, K.S.; Barloon, T.J.; Masuda, K.; Iowa Univ., IA

    1992-01-01

    The CT findings in 32 patients with pathologically proven metastases of the kidney were compared to findings in 74 patients with renal cell carcinoma. Fourteen CT criteria were chosen to describe and characterize the lesions and 2 radiologists evaluated the CT images retrospectively according to these criteria. Renal metastases were characterized as small, multiple, bilateral, wedge-shaped, less exophytic, and located within the renal capsule. Renal cell carcinomas were single, unilateral, nonwedge-shaped, and exophytic, and easily transgressed the renal capsule. The sensitivity of CT to discriminate renal cell carcinoma from renal metastasis was 93,2% for renal cell carcinoma, and to discriminate renal metastasis from renal cell carcinoma was 75,0% for renal metastases by computer posterior prohabilities. This study indicates that CT is usefull for distinguishing these clinically important tumors. By using posterior probability, some unnecessary biopsies may be avoided. (orig.)

  16. Pattern Recognition-Based Analysis of COPD in CT

    DEFF Research Database (Denmark)

    Sørensen, Lauge Emil Borch Laurs

    recognition part is used to turn the texture measures, measured in a CT image of the lungs, into a quantitative measure of disease. This is done by applying a classifier that is trained on a training set of data examples with known lung tissue patterns. Different classification systems are considered, and we...... will in particular use the pattern recognition concepts of supervised learning, multiple instance learning, and dissimilarity representation-based classification. The proposed texture-based measures are applied to CT data from two different sources, one comprising low dose CT slices from subjects with manually...... annotated regions of emphysema and healthy tissue, and one comprising volumetric low dose CT images from subjects that are either healthy or suffer from COPD. Several experiments demonstrate that it is clearly beneficial to take the lung tissue texture into account when classifying or quantifying emphysema...

  17. Analysis of chronic subdural hematoma based on CT, 3

    International Nuclear Information System (INIS)

    Takahashi, Yoshio; Mikami, Junichi; Ueda, Mikiya; Ito, Kazunori; Sato, Hiroyuki

    1984-01-01

    Forty-nine cases of chronic subdural hematoma experienced during the past 5 years were analyzed as to the number of days elapsed following head injury, symptoms, and computerized tomography (CT) findings. As a result, the clinical course of chronic subdural hematoma was devided into the following 5 stages on the basis of the presumed pathologic processes. The initial stage corresponded to a period of about 2 weeks after the precipitating injury; symptoms were absent; plain CT showed low-density areas (LDA); and metrizamide CT revealed metrizamide penetration into the LDA. The premature stage corresponded to a period of 2-4 weeks after trauma; no symptoms were present; plain CT showed LDA; and metrizamide CT revealed that metrizamide penetrated into the LDA with difficulty. The mature stage corresponded to a period of 30-60 days after trauma; CT showed iso-density areas (IDA) or high-density areas (HDA) with occasional enhancement effect; metrizamide penetration was not detected; and symptoms such as headache may have been present. The progressive stage typified chronic subdural hematoma; headache and focal symptoms were present; plain CT showed relative LDA, IDA, HDA or mixed-density areas (MDA); and enhancement of the contents of hematoma was observed in roughly half of the cases. The resolving stage was the stage in which hematoma had disappeared; plain CT showed relative LDA or LDA without mass sign; and metrizamide penetration was not detected. This clinical staging was useful in evaluating the pathologic picture of the chronic subdural hematoma and in determining suitable treatment. (author)

  18. Risk-benefit analysis and cost-effectiveness analysis of lung cancer screening by spiral CT

    International Nuclear Information System (INIS)

    Iinuma, Takeshi

    1999-01-01

    Mass screening of lung cancer has been widely performed using indirect chest X-ray method in Japan. However reduction of the mortality for lung cancer is questioned. We have proposed that recently developed spiral CT should be adopted for the screening of lung cancer, since CT has an excellent detectability for small nodule. Lung Cancer Screening CT (LSCT) has been developed by author's group using spiral CT with low dose and light weight in order to make a mobile unit. In this paper risk-benefit analysis and cost-effectiveness analysis are described for the LSCT screening of lung cancer. As a risk, radiation carcinogenesis due to exposure from LSCT are compared with gain of life-expectancy by screening and men of 40 years or more and women of 45 years or more are justified. The cost per person-year is estimated for LSCT screening which is better than that of present method, although total cost is higher. The LSCT screening could be recommended if total cost is affordable. (author)

  19. PET-CT in oncological patients: analysis of informal care costs in cost-benefit assessment.

    Science.gov (United States)

    Orlacchio, Antonio; Ciarrapico, Anna Micaela; Schillaci, Orazio; Chegai, Fabrizio; Tosti, Daniela; D'Alba, Fabrizio; Guazzaroni, Manlio; Simonetti, Giovanni

    2014-04-01

    The authors analysed the impact of nonmedical costs (travel, loss of productivity) in an economic analysis of PET-CT (positron-emission tomography-computed tomography) performed with standard contrast-enhanced CT protocols (CECT). From October to November 2009, a total of 100 patients referred to our institute were administered a questionnaire to evaluate the nonmedical costs of PET-CT. In addition, the medical costs (equipment maintenance and depreciation, consumables and staff) related to PET-CT performed with CECT and PET-CT with low-dose nonenhanced CT and separate CECT were also estimated. The medical costs were 919.3 euro for PET-CT with separate CECT, and 801.3 euro for PET-CT with CECT. Therefore, savings of approximately 13% are possible. Moreover, savings in nonmedical costs can be achieved by reducing the number of hospital visits required by patients undergoing diagnostic imaging. Nonmedical costs heavily affect patients' finances as well as having an indirect impact on national health expenditure. Our results show that PET-CT performed with standard dose CECT in a single session provides benefits in terms of both medical and nonmedical costs.

  20. Analysis of patient CT dose data using virtualdose

    Science.gov (United States)

    Bennett, Richard

    X-ray computer tomography has many benefits to medical and research applications. Recently, over the last decade CT has had a large increase in usage in hospitals and medical diagnosis. In pediatric care, from 2000 to 2006, abdominal CT scans increased by 49 % and chest CT by 425 % in the emergency room (Broder 2007). Enormous amounts of effort have been performed across multiple academic and government groups to determine an accurate measure of organ dose to patients who undergo a CT scan due to the inherent risks with ionizing radiation. Considering these intrinsic risks, CT dose estimating software becomes a necessary tool that health care providers and radiologist must use to determine many metrics to base the risks versus rewards of having an x-ray CT scan. This thesis models the resultant organ dose as body mass increases for patients with all other related scan parameters fixed. In addition to this,this thesis compares a modern dose estimating software, VirtualDose CT to two other programs, CT-Expo and ImPACT CT. The comparison shows how the software's theoretical basis and the phantom they use to represent the human body affect the range of results in organ dose. CT-Expo and ImPACT CT dose estimating software uses a different model for anatomical representation of the organs in the human body and the results show how that approach dramatically changes the outcome. The results categorizes four datasets as compared to the three software types where the appropriate phantom was available. Modeling was done to simulate chest abdominal pelvis scans and whole body scans. Organ dose difference versus body mass index shows as body mass index (BMI) ranges from 23.5 kg/m 2 to 45 kg/m2 the amount of organ dose also trends a percent change from -4.58 to -176.19 %. Comparing organ dose difference with increasing x-ray tube potential from 120 kVp to 140 kVp the percent change in organ dose increases from 55 % to 65 % across all phantoms. In comparing VirtualDose to CT

  1. Comparative analysis between spiral CT and pathology of pulmonary nodules

    International Nuclear Information System (INIS)

    Wang Kaifu; Zhang Zhanqing

    2007-01-01

    Objective: To explore the value of spiral CT in the diagnosis of atypical pulmonary nodules. Methods: CT, clinic and histopathologic data of 72 patients with atypical pulmonary nodules confirmed by surgical resection in 41 cases and/or biopsy in 31 cases were retrospectively analyzed. Results: CT scans demonstrated slight lobulation in 34 cases, irregular margin in 50 cases, long speculate in 10 cases, air-bronchogram in 2 case, vacuole in 2 case. 38 pulmonary cancer, 22 pulmonary tuberculosis and 12 pulmonary inflammatory pseudotumors were diagnosed with spiral CT. However, 30 pulmonary cancer, 30 pulmonary tuberculosis and 12 pulmonary inflammatory pseudotumors were confirmed by histopathology. The overall accurate diagnostic rate of pulmonary cancer was 66.7% (20/30), pulmonary tuberculosis was 60%(18/30), pulmonary inflammatory pseudotumors was 16.7%(2/12). 40 cases were diagnosed correctly and 32 cases were misdiagnosed with CT in 72 cases of atypical pulmonary nodules. The misdiagnostic rate of CT was 44.4%. 10 cases of lung cancer were misdiagnosed, including 4 cases of tuberculosis (long speculate or irregular margin) and 6 cases of inflammatory pseudotumors (irregular margin or long speculate or air-bronchogram). 12 cases of tuberculosis were misdiagnosed, including 8 cases lung cancer (slight lobulation) and 4 cases of inflammatory pseudotumors (slight lobulation). 10 cases inflammatory pseudotumor were misdiagnosed as lung cancer (slight lobulation). Conclusion: Spiral CT was very useful in the localization and morphological describing, but difficult in qualitative diagnosing of atypical pulmonary nodules, exactly diagnosis was relied on surgery and biopsy. (authors)

  2. CT analysis of intratumoral gas formation after hepatic tumor embolization

    International Nuclear Information System (INIS)

    Kim, Hyun Sook; Ahn, In Oak; Kim, Hyung Jin; Lee, Goo; Chung, Sung Hoon

    1994-01-01

    To evaluate the prevalence and the patterns of sterile gas shown at computed tomography(CT) after transarterial embolization(TAE) for primary hepatic tumor. Among 102 patients who performed TAE for hepatoma, thirty-four in whom follow-up CT was underwent constituted the basis of our study. At CT, we evaluated the patterns and locations of intratumoral gas. We also reviewed the clinical data to exclude an infectious origin of intratumoral gas. Of 34 patients, intratumoral gas was detected in 11 patients(32%), in all of whom Gelfoam was used as an embolic material. The initial tumor size measured at pre-TAE CT was larger in patients with intratumoral gas than in patients without it(p < 0.005). No specific patterns or locations of intratumoral gas were noted on CT scans. No patients had clinical signs and symptoms that suggested infection. Intratumoral gas formation without clinical evidence of infection is not an infrequent finding after TAE for hepatoma, especially when Gelfoam is used and when the tumor is larger in size. This finding may be a part of postinfarction syndrome and should not be misinterpreted as an postprocedural abscess formation

  3. Analysis of fatty liver by CT values in obese children

    International Nuclear Information System (INIS)

    Naganuma, Yoshihiro; Tomizawa, Shuichi; Ikarashi, Kozo; Tohyama, Jun; Ozawa, Kanzi; Uchiyama, Makoto.

    1996-01-01

    Liver attenuation values were measured by CT in 97 (183 times) obese children with ages 3 to 18 years and a diagnosis of fatty liver was made in 42 subjects. Liver/spleen ration from CT measurements showed a significant negative correlation with the percentage of standard body weight, and with the systolic pressure. In children with fatty liver, systolic pressure and serum GOT, GPT, ChE, TC, TG, ApoB and insulin were significantly higher than those in children without fatty liver. After a low-calorie dietary regimen and exercise therapy, the liver/spleen ratio and GPT improved in all children. The diagnosis of fatty infiltration (fatty liver) was made with a liver/spleen ratio of less than 1.0 as determined by the number of measurements taken, a reasonable criterion for the diagnosis of fatty liver by CT in children. There were some children with elevated GPT who showed normal CT findings. This may be caused by overnutrition which was associated with fatty infiltration, since GPT decreased in all these children after treatment. The present study suggests that CT is a useful procedure in diagnosing fatty liver, and in monitoring and determining efficacy of treatment in obese children. (author)

  4. Application of CT texture analysis in predicting histopathological characteristics of gastric cancers

    International Nuclear Information System (INIS)

    Liu, Shunli; Liu, Song; Ji, Changfeng; Zheng, Huanhuan; Pan, Xia; Zhang, Yujuan; He, Jian; Zhou, Zhengyang; Guan, Wenxian; Chen, Ling; Guan, Yue; Li, Weifeng; Ge, Yun

    2017-01-01

    To explore the application of computed tomography (CT) texture analysis in predicting histopathological features of gastric cancers. Preoperative contrast-enhanced CT images and postoperative histopathological features of 107 patients (82 men, 25 women) with gastric cancers were retrospectively reviewed. CT texture analysis generated: (1) mean attenuation, (2) standard deviation, (3) max frequency, (4) mode, (5) minimum attenuation, (6) maximum attenuation, (7) the fifth, 10th, 25th, 50th, 75th and 90th percentiles, and (8) entropy. Correlations between CT texture parameters and histopathological features were analysed. Mean attenuation, maximum attenuation, all percentiles and mode derived from portal venous CT images correlated significantly with differentiation degree and Lauren classification of gastric cancers (r, -0.231 ∝-0.324, 0.228 ∝ 0.321, respectively). Standard deviation and entropy derived from arterial CT images also correlated significantly with Lauren classification of gastric cancers (r = -0.265, -0.222, respectively). In arterial phase analysis, standard deviation and entropy were significantly lower in gastric cancers with than those without vascular invasion; however, minimum attenuation was significantly higher in gastric cancers with than those without vascular invasion. CT texture analysis held great potential in predicting differentiation degree, Lauren classification and vascular invasion status of gastric cancers. (orig.)

  5. Application of CT texture analysis in predicting histopathological characteristics of gastric cancers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shunli; Liu, Song; Ji, Changfeng; Zheng, Huanhuan; Pan, Xia; Zhang, Yujuan; He, Jian; Zhou, Zhengyang [The Affiliated Hospital of Nanjing University Medical School, Department of Radiology, Nanjing Drum Tower Hospital, Nanjing, Jiangsu Province (China); Guan, Wenxian [The Affiliated Hospital of Nanjing University Medical School, Department of Gastrointestinal Surgery, Nanjing Drum Tower Hospital, Nanjing (China); Chen, Ling [The Affiliated Hospital of Nanjing University Medical School, Department of Pathology, Nanjing Drum Tower Hospital, Nanjing, Jiangsu Province (China); Guan, Yue; Li, Weifeng; Ge, Yun [Nanjing University, School of Electronic Science and Engineering, Nanjing (China)

    2017-12-15

    To explore the application of computed tomography (CT) texture analysis in predicting histopathological features of gastric cancers. Preoperative contrast-enhanced CT images and postoperative histopathological features of 107 patients (82 men, 25 women) with gastric cancers were retrospectively reviewed. CT texture analysis generated: (1) mean attenuation, (2) standard deviation, (3) max frequency, (4) mode, (5) minimum attenuation, (6) maximum attenuation, (7) the fifth, 10th, 25th, 50th, 75th and 90th percentiles, and (8) entropy. Correlations between CT texture parameters and histopathological features were analysed. Mean attenuation, maximum attenuation, all percentiles and mode derived from portal venous CT images correlated significantly with differentiation degree and Lauren classification of gastric cancers (r, -0.231 ∝-0.324, 0.228 ∝ 0.321, respectively). Standard deviation and entropy derived from arterial CT images also correlated significantly with Lauren classification of gastric cancers (r = -0.265, -0.222, respectively). In arterial phase analysis, standard deviation and entropy were significantly lower in gastric cancers with than those without vascular invasion; however, minimum attenuation was significantly higher in gastric cancers with than those without vascular invasion. CT texture analysis held great potential in predicting differentiation degree, Lauren classification and vascular invasion status of gastric cancers. (orig.)

  6. 3D intrathoracic region definition and its application to PET-CT analysis

    Science.gov (United States)

    Cheirsilp, Ronnarit; Bascom, Rebecca; Allen, Thomas W.; Higgins, William E.

    2014-03-01

    Recently developed integrated PET-CT scanners give co-registered multimodal data sets that offer complementary three-dimensional (3D) digital images of the chest. PET (positron emission tomography) imaging gives highly specific functional information of suspect cancer sites, while CT (X-ray computed tomography) gives associated anatomical detail. Because the 3D CT and PET scans generally span the body from the eyes to the knees, accurate definition of the intrathoracic region is vital for focusing attention to the central-chest region. In this way, diagnostically important regions of interest (ROIs), such as central-chest lymph nodes and cancer nodules, can be more efficiently isolated. We propose a method for automatic segmentation of the intrathoracic region from a given co-registered 3D PET-CT study. Using the 3D CT scan as input, the method begins by finding an initial intrathoracic region boundary for a given 2D CT section. Next, active contour analysis, driven by a cost function depending on local image gradient, gradient-direction, and contour shape features, iteratively estimates the contours spanning the intrathoracic region on neighboring 2D CT sections. This process continues until the complete region is defined. We next present an interactive system that employs the segmentation method for focused 3D PET-CT chest image analysis. A validation study over a series of PET-CT studies reveals that the segmentation method gives a Dice index accuracy of less than 98%. In addition, further results demonstrate the utility of the method for focused 3D PET-CT chest image analysis, ROI definition, and visualization.

  7. Analysis of cranial CT-scan findings in cerebral palsy

    International Nuclear Information System (INIS)

    Wada, Fumio; Andoh, Tadashi; Une, Koji; Takamatsu, Tsurukichi

    1981-01-01

    CT-scan findings of 87 cerebral palsied children were studied. They consist of 23 cases of spastic quadriplegia, 9 cases of diplegia, 12 cases of paraplegia, 24 cases of athetosis and mixed type, and 19 cases of hemiplegia. In the former four types, ventricular dilatation and cortical atrophy were measured and abnormal changes in cerebral substance and cerebellar atrophy were observed. Spastic quadriplegia showed most intense changes in every aspect of the abnormalities, while paraplegia had almost normal appearance. Athetosis and mixed type had moderate changes. Hemiplegia always showed asymmetrical view on CT-scan, dilatation of lateral ventricle or atrophy of hemisphere in contralateral side being observed. (author)

  8. Analysis of cranial CT-scan findings in cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

    Wada, F.; Andoh, T.; Une, K.; Takamatsu, T. (Kitakyushu Municipal Sogo-Ryoiku Center (Japan))

    1981-06-01

    CT-scan findings of 87 cerebral palsied children were studied. They consist of 23 cases of spastic quadriplegia, 9 cases of diplegia, 12 cases of paraplegia, 24 cases of athetosis and mixed type, and 19 cases of hemiplegia. In the former four types, ventricular dilatation and cortical atrophy were measured and abnormal changes in cerebral substance and cerebellar atrophy were observed. Spastic quadriplegia showed most intense changes in every aspect of the abnormalities, while paraplegia had almost normal appearance. Athetosis and mixed type had moderate changes. Hemiplegia always showed asymmetrical view on CT-scan, dilatation of lateral ventricle or atrophy of hemisphere in contralateral side being observed.

  9. Principal component analysis of the CT density histogram to generate parametric response maps of COPD

    Science.gov (United States)

    Zha, N.; Capaldi, D. P. I.; Pike, D.; McCormack, D. G.; Cunningham, I. A.; Parraga, G.

    2015-03-01

    Pulmonary x-ray computed tomography (CT) may be used to characterize emphysema and airways disease in patients with chronic obstructive pulmonary disease (COPD). One analysis approach - parametric response mapping (PMR) utilizes registered inspiratory and expiratory CT image volumes and CT-density-histogram thresholds, but there is no consensus regarding the threshold values used, or their clinical meaning. Principal-component-analysis (PCA) of the CT density histogram can be exploited to quantify emphysema using data-driven CT-density-histogram thresholds. Thus, the objective of this proof-of-concept demonstration was to develop a PRM approach using PCA-derived thresholds in COPD patients and ex-smokers without airflow limitation. Methods: Fifteen COPD ex-smokers and 5 normal ex-smokers were evaluated. Thoracic CT images were also acquired at full inspiration and full expiration and these images were non-rigidly co-registered. PCA was performed for the CT density histograms, from which the components with the highest eigenvalues greater than one were summed. Since the values of the principal component curve correlate directly with the variability in the sample, the maximum and minimum points on the curve were used as threshold values for the PCA-adjusted PRM technique. Results: A significant correlation was determined between conventional and PCA-adjusted PRM with 3He MRI apparent diffusion coefficient (p<0.001), with CT RA950 (p<0.0001), as well as with 3He MRI ventilation defect percent, a measurement of both small airways disease (p=0.049 and p=0.06, respectively) and emphysema (p=0.02). Conclusions: PRM generated using PCA thresholds of the CT density histogram showed significant correlations with CT and 3He MRI measurements of emphysema, but not airways disease.

  10. CT Findings of Small Bowel Anisakiasis: Analysis of Four Cases

    International Nuclear Information System (INIS)

    Kim, Wee Kyoung; Song, Soon Young; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Jung, Woo Kyoung; Kim, Min Yeong

    2011-01-01

    We wanted to describe the CT findings of small bowel anisakiasis with the pathologic correlation. Four patients with surgically and pathologically proven small bowel anisakiasis were included in this retrospective study. They were three men and one woman and their ages ranged from 28 to 43 years (mean age: 38 years). We evaluated their clinical, CT and histological findings. All the patients had a history of ingesting raw fish within 24 hours from the time of symptom onset. They complained of abdominal pain (n=4), nausea (n=4), vomiting (n=2) and diarrhea (n=1). Physical examination revealed tenderness (n=4), rebound tenderness (n=4) and increased bowel sounds (n=3). Leukocytosis was noted in all the patients on the laboratory examination. None of the patients showed eosinophilia. The CT findings were segmental small bowel wall thickening with preserved layering (n=4), focal segmental luminal narrowing with proximal dilatation (n=4), peritoneal thickening (n=3), mesenteric or omental infiltration (n=4) and varying degrees of ascites (n=4). On the histopathologic examination, they revealed an infiltration of eosinophils (n=4) in all layers of the bowel wall with severe edema. The larvae were found on surgico-pathologic examination in all the cases. The CT findings may be helpful to make the specific diagnosis of small bowel anisakiasis in a patient with the clinical findings of an acute abdomen and a history of eating raw fish

  11. CT Findings of Small Bowel Anisakiasis: Analysis of Four Cases

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Wee Kyoung; Song, Soon Young; Cho, On Koo; Koh, Byung Hee [Hanyang University College of Medicine, Seoul (Korea, Republic of); Kim, Yong Soo; Jung, Woo Kyoung; Kim, Min Yeong [Hanyang University Guri Hospital, College of Medicine, Guri (Korea, Republic of)

    2011-02-15

    We wanted to describe the CT findings of small bowel anisakiasis with the pathologic correlation. Four patients with surgically and pathologically proven small bowel anisakiasis were included in this retrospective study. They were three men and one woman and their ages ranged from 28 to 43 years (mean age: 38 years). We evaluated their clinical, CT and histological findings. All the patients had a history of ingesting raw fish within 24 hours from the time of symptom onset. They complained of abdominal pain (n=4), nausea (n=4), vomiting (n=2) and diarrhea (n=1). Physical examination revealed tenderness (n=4), rebound tenderness (n=4) and increased bowel sounds (n=3). Leukocytosis was noted in all the patients on the laboratory examination. None of the patients showed eosinophilia. The CT findings were segmental small bowel wall thickening with preserved layering (n=4), focal segmental luminal narrowing with proximal dilatation (n=4), peritoneal thickening (n=3), mesenteric or omental infiltration (n=4) and varying degrees of ascites (n=4). On the histopathologic examination, they revealed an infiltration of eosinophils (n=4) in all layers of the bowel wall with severe edema. The larvae were found on surgico-pathologic examination in all the cases. The CT findings may be helpful to make the specific diagnosis of small bowel anisakiasis in a patient with the clinical findings of an acute abdomen and a history of eating raw fish

  12. Sequential analysis of CT findings in herpes simplex encephalitis

    International Nuclear Information System (INIS)

    Kawamura, Mitsuru; Tokumaru, Yukio; Ito, Naoki; Yamada, Tatsuo; Hirayama, Keizo

    1982-01-01

    CT findings of six patients with serologically confirmed herpes simplex encephalitis were analyzed sequentially. The initial change in CT scan in 3 cases was generalized cerebral edema instead of low density areas in the anterior temporal lobes, which have generally been known as the initial findings. Then, bilateral (5 cases) or unilateral (1 case) island-shaped low absorption areas in the insular cortex and the claustrum appeared within 10 days of onset in all 6 cases. These findings, especially the latter, seem to be characteristic of the acute stage and useful in the early diagnosis of herpes simplex encephalitis. The low density areas, then, spread to the temporal lobes, rectal and cingulate gyri in the subacute stage (3 cases) and finally to the frontal and occipital lobes in the chronic stage (2 cases). In the basal ganglia, thalamus, brain stem and cerebellum, however, there were no low density areas. In 2 cases there was no progression of low density areas beyond those of the acute stage. In one case there were high density areas in the temporal lobes and parapontine cisterns bilaterally. This could correspond to the pathological findings in herpes simplex encephalitis. The improvement of CT findings (or arrest at the early stage) was noted in 2 cases in which the clinical state also improved. This might well be the effect of adenine arabinoside. The one case treated with cytosine arabinoside had extensive low density areas in CT and finally died. The importance of CT in the evaluation of adenine arabinoside therapy was stressed. (author)

  13. Activity-based cost analysis of hepatic tumor ablation using CT-guided high-dose rate brachytherapy or CT-guided radiofrequency ablation in hepatocellular carcinoma.

    Science.gov (United States)

    Schnapauff, D; Collettini, F; Steffen, I; Wieners, G; Hamm, B; Gebauer, B; Maurer, M H

    2016-02-25

    To analyse and compare the costs of hepatic tumor ablation with computed tomography (CT)-guided high-dose rate brachytherapy (CT-HDRBT) and CT-guided radiofrequency ablation (CT-RFA) as two alternative minimally invasive treatment options of hepatocellular carcinoma (HCC). An activity based process model was created determining working steps and required staff of CT-RFA and CT-HDRBT. Prorated costs of equipment use (purchase, depreciation, and maintenance), costs of staff, and expenditure for disposables were identified in a sample of 20 patients (10 treated by CT-RFA and 10 by CT-HDRBT) and compared. A sensitivity and break even analysis was performed to analyse the dependence of costs on the number of patients treated annually with both methods. Costs of CT-RFA were nearly stable with mean overall costs of approximately 1909 €, 1847 €, 1816 € and 1801 € per patient when treating 25, 50, 100 or 200 patients annually, as the main factor influencing the costs of this procedure was the single-use RFA probe. Mean costs of CT-HDRBT decreased significantly per patient ablation with a rising number of patients treated annually, with prorated costs of 3442 €, 1962 €, 1222 € and 852 € when treating 25, 50, 100 or 200 patients, due to low costs of single-use disposables compared to high annual fix-costs which proportionally decreased per patient with a higher number of patients treated annually. A break-even between both methods was reached when treating at least 55 patients annually. Although CT-HDRBT is a more complex procedure with more staff involved, it can be performed at lower costs per patient from the perspective of the medical provider when treating more than 55 patients compared to CT-RFA, mainly due to lower costs for disposables and a decreasing percentage of fixed costs with an increasing number of treatments.

  14. Analysis of chronic subdural hematoma based on CT, (2)

    International Nuclear Information System (INIS)

    Takahashi, Yoshio; Mikami, Junichi; Sato, Hiroyuki; Takeda, Satoshi; Matsuoka, Takahiro

    1982-01-01

    Twenty-three cases of chronic subdural hematoma were observed soon after head injury for the relationship between its CT findings and clinical symptoms. It has been found that the chronic subdural hematoma is a slowly growing and expanding intracranial disease that starts in an early period of head injury. Chronic subdural hematoma did not present any signs or symptoms initially, except for the gradual occurrence of headache, but finally it presented signs of intracranial hypertension and focal signs. Chronic subdural hematoma in the hygroma-like period did not show any signs and symptoms. In the capsulated period, when changes in CT density suggested intracapsular hemorrhage, a heavy sensation of the head was noted. It was recognized as an abnormal feeling or a full sensation of the head. When the bleeding continued in the cavity, headache became continuous and focal signs gradually appeared. (author)

  15. The cryptogenic organizing pneumonia: the analysis of CT features

    International Nuclear Information System (INIS)

    Zhu Xiaohua; Li Tiannv; You Zhengqian; Ma Jun; Jiang Sen

    2007-01-01

    Objective: To improve our understanding concerning radiographic manifestations of cryptogenic organizing pneumonia (COP). Methods: The diagnosis of cryptogenic organizing pneumonia was made based on clinical and radiological features, and was verified with lung biopsy and pathological examination in 23 cases. All data were analyzed and relevant literatures were reviewed. Results: CT scans revealed multi- patch shadows, patchy air-space consolidations in 15 cases, often located in predominantly subpleural and(or) both inferior lungs, with or ground-glass opacities, bronchiectasis, and cords. Lesion sites changed over time in some patients. Corticosteroid treatment led to significant improvement in most cases. Conclusions: The diagnosis of cryptogenic organizing pneumonia required the converging evidence from clinical and radiological manifestations as well as pathologies. It is important to appreciate CT manifestations of COP. (authors)

  16. CT findings and analysis for misdiagnosis of female pelvic tuberculosis

    Directory of Open Access Journals (Sweden)

    Shambhu Kumar Sah

    2017-03-01

    Conclusions: Integrated with clinical history and laboratory tests, pelvic tuberculosis should be considered in young female patients with elevated CA125 and CT findings of adnexal mixed (solid and cystic mass with multilocular caseous necrotic enhancement, high density ascites, thickened and enhanced peritoneum. Early diagnosis of the disease is a key consideration for early institution of anti-TB therapy to avoid misdiagnosis and surgical explorations.

  17. Thoracic cavity definition for 3D PET/CT analysis and visualization.

    Science.gov (United States)

    Cheirsilp, Ronnarit; Bascom, Rebecca; Allen, Thomas W; Higgins, William E

    2015-07-01

    X-ray computed tomography (CT) and positron emission tomography (PET) serve as the standard imaging modalities for lung-cancer management. CT gives anatomical details on diagnostic regions of interest (ROIs), while PET gives highly specific functional information. During the lung-cancer management process, a patient receives a co-registered whole-body PET/CT scan pair and a dedicated high-resolution chest CT scan. With these data, multimodal PET/CT ROI information can be gleaned to facilitate disease management. Effective image segmentation of the thoracic cavity, however, is needed to focus attention on the central chest. We present an automatic method for thoracic cavity segmentation from 3D CT scans. We then demonstrate how the method facilitates 3D ROI localization and visualization in patient multimodal imaging studies. Our segmentation method draws upon digital topological and morphological operations, active-contour analysis, and key organ landmarks. Using a large patient database, the method showed high agreement to ground-truth regions, with a mean coverage=99.2% and leakage=0.52%. Furthermore, it enabled extremely fast computation. For PET/CT lesion analysis, the segmentation method reduced ROI search space by 97.7% for a whole-body scan, or nearly 3 times greater than that achieved by a lung mask. Despite this reduction, we achieved 100% true-positive ROI detection, while also reducing the false-positive (FP) detection rate by >5 times over that achieved with a lung mask. Finally, the method greatly improved PET/CT visualization by eliminating false PET-avid obscurations arising from the heart, bones, and liver. In particular, PET MIP views and fused PET/CT renderings depicted unprecedented clarity of the lesions and neighboring anatomical structures truly relevant to lung-cancer assessment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The analysis of initial cranial CT of early hematoma enlargement in spontaneous intracerebral hemorrhage

    OpenAIRE

    BEI Yu-zhang; CHEN Ben-yang; QI Hao-bo; ZHOU Zheng-ping; LI Yu-bo

    2012-01-01

    Objective To investigate the predictive effect of initial cranial CT on early hematoma enlargement in spontaneous intracerebral hemorrhage. Methods Three hundred patients with spontaneous intracerebral hemorrhage within 6 hours after onset were studied. Chi-square test and logistic regression analysis were used to detect the related factors which may indicate hematoma enlargement. Results Sixty-one (20.33% ) patients presented hematoma enlargement on cranial CT. Single factor and multivariate...

  19. Impact of {sup 18}F-FDG PET/CT on the management of adrenocortical carcinoma: analysis of 106 patients

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Satoshi; Macapinlac, Homer A.; Chuang, Hubert H. [The University of Texas MD Anderson Cancer Center, Department of Nuclear Medicine, Houston, TX (United States); Balachandran, Aparna [The University of Texas MD Anderson Cancer Center, Department of Diagnostic Radiology, Houston, TX (United States); Habra, Mouhammed Amir [The University of Texas MD Anderson Cancer Center, Department of Endocrine Neoplasia and Hormonal Disorders, Houston, TX (United States); Phan, Alexandria T. [The University of Texas MD Anderson Cancer Center, Department of Gastrointestinal Medical Oncology, Houston, TX (United States); Bassett, Roland L. [The University of Texas MD Anderson Cancer Center, Department of Biostatistics, Houston, TX (United States)

    2014-11-15

    Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy. Limited data are available about on value of {sup 18}F-FDG PET/CT in ACC. We evaluated the impact of PET/CT on the management of ACC. We performed a retrospective review in patients with ACC who had undergone PET/CT. The impact of PET/CT on the management plan was evaluated by comparing the findings on PET/CT to the findings on contrast-enhanced CT. The sensitivity, specificity, and accuracy of each form of imaging were calculated. The correlations between PET/CT parameters, including maximum standardized uptake value (SUV{sub max}), total lesion glycolysis, and decline in SUV{sub max} after chemotherapy, and clinical outcome were evaluated. Included in the analysis were 106 patients with 180 PET/CT scans. Of the 106 patients, 7 underwent PET/CT only for initial staging, 84 underwent PET/CT only for restaging, and 15 underwent PET/CT for both initial staging and restaging. PET/CT changed the management plan in 1 of 22 patients (5 %) at initial staging and 9 of 99 patients (9 %) at restaging. In 5 of the patients in whom PET/CT changed the management plan, PET/CT showed response to chemotherapy but contrast-enhanced CT showed stable disease. Sensitivity, specificity, and accuracy were 100 %, 100 %, and 100 % for PET/CT at initial staging; 92.6 %, 100 %, and 96.4 % for CT at initial staging; 98.4 %, 100 %, and 99.5 % for PET/CT at restaging; and 96.8 %, 98.6 %, and 98.0 % for CT at restaging, respectively. No PET/CT parameters were associated with survival at either initial diagnosis or recurrence. PET/CT findings could substantially change the management plan in a small proportion of patients with ACC. Although lesion detection was similar between PET/CT and CT, PET/CT may be preferred for chemotherapeutic response assessment because it may predict response before anatomic changes are detected on CT. (orig.)

  20. Diagnostic sensitivity of Tc-99m HYNIC PSMA SPECT/CT in prostate carcinoma: A comparative analysis with Ga-68 PSMA PET/CT.

    Science.gov (United States)

    Lawal, Ismaheel O; Ankrah, Alfred O; Mokgoro, Neo P; Vorster, Mariza; Maes, Alex; Sathekge, Mike M

    2017-08-01

    Emerging data from published studies are demonstrating the superiority of Ga-68 PSMA PET/CT imaging in prostate cancer. However, the low yield of the Ge-68/Ga-68 from which Gallium-68 is obtained and fewer installed PET/CT systems compared to the SPECT imaging systems may limit its availability. We, therefore, evaluated in a head-to-head comparison, the diagnostic sensitivity of Ga-68 PSMA PET/CT and Tc-99m PSMA SPECT/CT in patients with prostate cancer. A total of 14 patients with histologically confirmed prostate cancer were prospectively recruited to undergo Ga-68 PSMA PET/CT and Tc-99m HYNIC PSMA SPECT/CT. The mean age of patients was 67.21 ± 8.15 years and the median PSA level was 45.18 ng/mL (range = 1.51-687 ng/mL). SUVmax of all lesions and the size of lymph nodes with PSMA avidity on Ga-68 PSMA PET/CT were determined. Proportions of these lesions detected on Tc-99m HYNIC PSMA SPECT/CT read independent of PET/CT findings were determined. A total of 46 lesions were seen on Ga-68 PSMA PET/CT localized to the prostate (n = 10), lymph nodes (n = 24), and bones (n = 12). Of these, Tc-99m HYNIC PSMA SPECT/CT detected 36 lesions: Prostate = 10/10 (100%), lymph nodes = 15/24 (62.5%), and bones = 11/12 (91.7%) with an overall sensitivity of 78.3%. Lesions detected on Tc-99m HYNIC PSMA SPECT/CT were bigger in size (P Tc-99m HYNIC PSMA SPECT/CT. In a univariate analysis, Lymph node size (P = 0.033) and the SUVmax of all lesions (P = 0.007) were significant predictors of lesion detection on Tc-99m HYNIC PSMA SPECT/CT. Tc-99m HYNIC PSMA may be a useful in imaging of prostate cancer although with a lower sensitivity for lesion detection compared to Ga-68 PSMA PET/CT. Its use is recommended when Ga-68 PSMA is not readily available, in planning radio-guided surgery or the patient is being considered for radio-ligand therapy with Lu-177 PSMA. It performs poorly in detecting small-sized lesions hence its use is not recommended

  1. TH-C-18A-08: A Management Tool for CT Dose Monitoring, Analysis, and Protocol Review

    International Nuclear Information System (INIS)

    Wang, J; Chan, F; Newman, B; Larson, D; Leung, A; Fleischmann, D; Molvin, L; Marsh, D; Zorich, C; Phillips, L

    2014-01-01

    Purpose: To develop a customizable tool for enterprise-wide managing of CT protocols and analyzing radiation dose information of CT exams for a variety of quality control applications Methods: All clinical CT protocols implemented on the 11 CT scanners at our institution were extracted in digital format. The original protocols had been preset by our CT management team. A commercial CT dose tracking software (DoseWatch,GE healthcare,WI) was used to collect exam information (exam date, patient age etc.), scanning parameters, and radiation doses for all CT exams. We developed a Matlab-based program (MathWorks,MA) with graphic user interface which allows to analyze the scanning protocols with the actual dose estimates, and compare the data to national (ACR,AAPM) and internal reference values for CT quality control. Results: The CT protocol review portion of our tool allows the user to look up the scanning and image reconstruction parameters of any protocol on any of the installed CT systems among about 120 protocols per scanner. In the dose analysis tool, dose information of all CT exams (from 05/2013 to 02/2014) was stratified on a protocol level, and within a protocol down to series level, i.e. each individual exposure event. This allows numerical and graphical review of dose information of any combination of scanner models, protocols and series. The key functions of the tool include: statistics of CTDI, DLP and SSDE, dose monitoring using user-set CTDI/DLP/SSDE thresholds, look-up of any CT exam dose data, and CT protocol review. Conclusion: our inhouse CT management tool provides radiologists, technologists and administration a first-hand near real-time enterprise-wide knowledge on CT dose levels of different exam types. Medical physicists use this tool to manage CT protocols, compare and optimize dose levels across different scanner models. It provides technologists feedback on CT scanning operation, and knowledge on important dose baselines and thresholds

  2. Differentiation of adrenal adenomas from nonadenomas using CT histogram analysis method: A prospective study

    International Nuclear Information System (INIS)

    Halefoglu, Ahmet Mesrur; Bas, Nagihan; Yasar, Ahmet; Basak, Muzaffer

    2010-01-01

    Objective: The objective of our study was to prospectively evaluate the effectiveness of computed tomography (CT) histogram analysis method in the differentiation of benign and malignant adrenal masses. Materials and Methods: Between March 2007 and June 2008, 94 patients (46 males, 48 females, age range: 30-79 years, mean age: 57.7 years) with 113 adrenal masses (mean diameter: 3.03 cm, range: 1.07-8.02 cm) were prospectively evaluated. These included 66 adenomas, 45 metastases and 2 pheochromocytomas. Histogram analysis method was performed using a circular region of interest (ROI) and mean attenuation, total number of pixels, number of negative pixels and subsequent percentage of negative pixels were detected on both unenhanced and delayed contrast-enhanced CT images for each adrenal mass. A mean attenuation threshold of 10 Hounsfield unit (HU) for unenhanced CT and 5% and 10% negative pixel thresholds for both unenhanced and delayed contrast-enhanced CT were calculated by a consensus of at least two reviewers and the correlation between mean attenuation and percentage of negative pixels was determined. Final diagnoses were based on imaging follow-up of minimum 6 months, biopsy, surgery and adrenal washout study. Results: 51 of 66 adenomas (77.3%) showed attenuation values of ≤10 HU and 15 (22.7%) adenomas showed more than 10 HU on unenhanced CT. All of these adenomas contained negative pixels on unenhanced CT. Eight of 66 (12.1%) adenomas showed a mean attenuation value of ≤10 HU on delayed contrast-enhanced scans and 45 adenomas (68.2%) persisted on containing negative pixels. All metastases had an attenuation value of greater than 10 HU on unenhanced CT images. 21 of 45 (46.6%) metastases contained negative pixels on unenhanced images but only seven metastases (15.5%) had negative pixels on delayed contrast-enhanced images. Two pheochromocytomas had negative pixels on both unenhanced and delayed contrast-enhanced CT images. Increase in the percentage of

  3. Data Analysis of Medical Images: CT, MRI, Phase Contrast X-ray and PET

    DEFF Research Database (Denmark)

    Christensen, Anders Nymark

    of micro-CT images followed by a statistical analysis of homogeneity, contrast, degradation, and other qualities. By combining knowledge from the different professions in the project, a new application for one of the developed gels - in-vivo dosimetry in radiotherapy - has been studied. Analysis...

  4. Morphological analysis of enlarged ventricle on CT image, using multivariate analysis

    International Nuclear Information System (INIS)

    Iwasaki, Satoru; Kichikawa, Kimihiko; Otsuji, Hideyuki; Fukusumi, Akio; Kobayashi, Yasuo.

    1983-01-01

    Multivariate analysis of enlarged cerebral ventricle on CT was undertaken to study the characteristics of ventricular morphology. Several ventricular segments of enlarged ventricle, defined on the basis of the study of normal group, were linearly measured on CT image. Then the discriminant analysis with the increase and decrease of variable was applied. The following are the results obtained. The error ratio of discrimination between pressure hydrocephalus and cerebral atrophy was 8.4 %, and between obstructive hydrocephalus and communicating hydrocephalus was 11.3 %. Ventricular segments were divided into three groups according to their character of enlargement: (1) the temporal horn and trigone are large in pressure hydrocephalus; (2) the hypothalamic segment of the third ventricle and the body of lateral ventricle are larger in obstructive hydrocephalus than in communicating hydrocephalus; (3) the anterior horn, cellae mediae at the level of the head of caudate nuclei and thalamic segment of the third ventricle are relatively large in cerebral atrophy and communicating hydrocephalus. The hypothalamic segment of the third ventricle assumes a round or oval shape in pressure hydrocephalus but a rectangular or teardrop shape in cerebral atrophy. These findings are contributory to pathological evaluation of ventricular enlargement. (author)

  5. Quantitative CT analysis of honeycombing area in idiopathic pulmonary fibrosis: Correlations with pulmonary function tests.

    Science.gov (United States)

    Nakagawa, Hiroaki; Nagatani, Yukihiro; Takahashi, Masashi; Ogawa, Emiko; Tho, Nguyen Van; Ryujin, Yasushi; Nagao, Taishi; Nakano, Yasutaka

    2016-01-01

    The 2011 official statement of idiopathic pulmonary fibrosis (IPF) mentions that the extent of honeycombing and the worsening of fibrosis on high-resolution computed tomography (HRCT) in IPF are associated with the increased risk of mortality. However, there are few reports about the quantitative computed tomography (CT) analysis of honeycombing area. In this study, we first proposed a computer-aided method for quantitative CT analysis of honeycombing area in patients with IPF. We then evaluated the correlations between honeycombing area measured by the proposed method with that estimated by radiologists or with parameters of PFTs. Chest HRCTs and pulmonary function tests (PFTs) of 36 IPF patients, who were diagnosed using HRCT alone, were retrospectively evaluated. Two thoracic radiologists independently estimated the honeycombing area as Identified Area (IA) and the percentage of honeycombing area to total lung area as Percent Area (PA) on 3 axial CT slices for each patient. We also developed a computer-aided method to measure the honeycombing area on CT images of those patients. The total honeycombing area as CT honeycombing area (HA) and the percentage of honeycombing area to total lung area as CT %honeycombing area (%HA) were derived from the computer-aided method for each patient. HA derived from three CT slices was significantly correlated with IA (ρ=0.65 for Radiologist 1 and ρ=0.68 for Radiologist 2). %HA derived from three CT slices was also significantly correlated with PA (ρ=0.68 for Radiologist 1 and ρ=0.70 for Radiologist 2). HA and %HA derived from all CT slices were significantly correlated with FVC (%pred.), DLCO (%pred.), and the composite physiologic index (CPI) (HA: ρ=-0.43, ρ=-0.56, ρ=0.63 and %HA: ρ=-0.60, ρ=-0.49, ρ=0.69, respectively). The honeycombing area measured by the proposed computer-aided method was correlated with that estimated by expert radiologists and with parameters of PFTs. This quantitative CT analysis of

  6. Analysis of discrepancy between neurologic findings and CT findings in 60 patients with herniated nucleus pulposus

    International Nuclear Information System (INIS)

    Lee, Hyun; Kim, Kab Tae; Sol, Chang Hyo; Kim, Byung Soo

    1987-01-01

    The herniated nucleus pulposus (HNP) is a major cause of low back pain and sciatica. High resolution computed tomography is the most accurate diagnostic tool to define a HNP, because it provides a complete in vivo analysis of bony framework of lumbar spine as well as the supporting soft tissue structures and neural elements. But the discrepancy between neurologic findings and CT findings is often confusing. From May 1983 to August 1986, sixty patients with HNP who had both CT and surgical intervention at Pusan National University Hospital were analyzed. The feasibility of the neurologic examination on HNP and the effect of HNP on nerve root were evaluated on the basis of CT findings. The results were as follows : 1. Thirty-four cases (56.7%) of clinical impression were matched to CT findings in determining level of HNP and affected nerve root. 2. In evaluation of affected level, there was high trend to cause discrepancy between neurologic findings and CT findings in multiple disc involvement than in single involvement. 3. There was no correlation between degree of nerve root compression determined by CT and pattern of neurologic signs (motor weakness, sensory deficit, and reflex change)

  7. Analysis of discrepancy between neurologic findings and CT findings in 60 patients with herniated nucleus pulposus

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun; Kim, Kab Tae; Sol, Chang Hyo; Kim, Byung Soo [College of Medicine, Pusan National University, Busan(Korea, Republic of)

    1987-06-15

    The herniated nucleus pulposus (HNP) is a major cause of low back pain and sciatica. High resolution computed tomography is the most accurate diagnostic tool to define a HNP, because it provides a complete in vivo analysis of bony framework of lumbar spine as well as the supporting soft tissue structures and neural elements. But the discrepancy between neurologic findings and CT findings is often confusing. From May 1983 to August 1986, sixty patients with HNP who had both CT and surgical intervention at Pusan National University Hospital were analyzed. The feasibility of the neurologic examination on HNP and the effect of HNP on nerve root were evaluated on the basis of CT findings. The results were as follows : 1. Thirty-four cases (56.7%) of clinical impression were matched to CT findings in determining level of HNP and affected nerve root. 2. In evaluation of affected level, there was high trend to cause discrepancy between neurologic findings and CT findings in multiple disc involvement than in single involvement. 3. There was no correlation between degree of nerve root compression determined by CT and pattern of neurologic signs (motor weakness, sensory deficit, and reflex change)

  8. Quantitative analysis of calcification of the abdominal aorta by CT

    International Nuclear Information System (INIS)

    Watanabe, Hiromi; Kubota, Kazuo; Ito, Kengo; Ono, Shuichi; Matsuzawa, Taiju

    1983-01-01

    Of the abdominal aorta, the relationship between the calcification index (C.I.) obtained from CT films and the atheromatous surface involved (S.I.) obtained from autopsy specimens was studied. The relations of C.I. to hypertension and hyperlipidemia were also analyzed. The coefficient of correlation between C.I. and S.I. was 0.83 (p< 0.001). Compared with a non-hypertensive group, the hypertensives showed a higher C.I., and such a difference was great in the male patients in their 50s and females in their 60s and 70s. The male patients with hyperlipidemia did not show definite differences in C.I. from the non-hyperlipidemia group, but the female patients in their 60s and 70s showed significantly higher values. (Chiba, N.)

  9. Analysis of aliasing artifacts in 16-slice helical CT

    International Nuclear Information System (INIS)

    Chen Wei; Liu Jingkang; Ou Xiaoguang; Li Wenzheng; Liao Weihua; Yan Ang

    2006-01-01

    Objective: To recognize the features of aliasing artifacts on CT images, and to investigate the effects of imaging parameters on the magnitude of this artifacts. Methods: An adult dry skull was placed in a plastic water-filled container and scanned with a PHILIPS 16-slice helical CT. All the acquired transaxial images by using several different acquisition or reconstruction parameters were examined for comparative assessment of the aliasing artifacts. Results: The aliasing artifacts could be seen in most instances and characterized as the spokewise patterns emanating from the edges of high contrast structure as its radius varies sharply in the longitudinal direction. The images that scanned with pitch of 0.3, 0.6 and 0.9, respectively, showed aliasing artifacts, and its severities increased with pitches escalated (detector combination 16 x 1.5, reconstruction thickness 2 mm); There were more significant aliasing artifacts on the images reconstructed with 0.8 mm slice width compared with 1-mm slice width, and no aliasing artifacts were observed on the images reconstructed with 2-mm slice width (detector combination 16 x 0.75, pitch 0.6); No artifacts were perceived on the images scanned with detector combination 16 x 0.75, while presented evidently with the use of detector combination 16 x 1.5 (pitch 0.6, reconstruction thickness 2 mm); The degrees of aliasing artifacts were unaltered when reconstruction interval and tube current changed. Conclusions: Aliasing artifacts are caused by undersampling. When the operator choose the thinner sampling thickness, lower pitch and a much wider reconstruction thickness judiciously, aliasing artifacts could be effectively mitigated or suppressed. (authors)

  10. Visual grading characteristics and ordinal regression analysis during optimisation of CT head examinations.

    Science.gov (United States)

    Zarb, Francis; McEntee, Mark F; Rainford, Louise

    2015-06-01

    To evaluate visual grading characteristics (VGC) and ordinal regression analysis during head CT optimisation as a potential alternative to visual grading assessment (VGA), traditionally employed to score anatomical visualisation. Patient images (n = 66) were obtained using current and optimised imaging protocols from two CT suites: a 16-slice scanner at the national Maltese centre for trauma and a 64-slice scanner in a private centre. Local resident radiologists (n = 6) performed VGA followed by VGC and ordinal regression analysis. VGC alone indicated that optimised protocols had similar image quality as current protocols. Ordinal logistic regression analysis provided an in-depth evaluation, criterion by criterion allowing the selective implementation of the protocols. The local radiology review panel supported the implementation of optimised protocols for brain CT examinations (including trauma) in one centre, achieving radiation dose reductions ranging from 24 % to 36 %. In the second centre a 29 % reduction in radiation dose was achieved for follow-up cases. The combined use of VGC and ordinal logistic regression analysis led to clinical decisions being taken on the implementation of the optimised protocols. This improved method of image quality analysis provided the evidence to support imaging protocol optimisation, resulting in significant radiation dose savings. • There is need for scientifically based image quality evaluation during CT optimisation. • VGC and ordinal regression analysis in combination led to better informed clinical decisions. • VGC and ordinal regression analysis led to dose reductions without compromising diagnostic efficacy.

  11. Quantitative Analysis of Micro-CT Imaging and Histopathological Signatures of Experimental Arthritis in Rats

    Directory of Open Access Journals (Sweden)

    Matthew D. Silva

    2004-10-01

    Full Text Available Micro-computed tomographic (micro-CT imaging provides a unique opportunity to capture 3-D architectural information in bone samples. In this study of pathological joint changes in a rat model of adjuvant-induced arthritis (AA, quantitative analysis of bone volume and roughness were performed by micro-CT imaging and compared with histopathology methods and paw swelling measurement. Micro-CT imaging of excised rat hind paws (n = 10 stored in formalin consisted of approximately 600 30-μm slices acquired on a 512 × 512 image matrix with isotropic resolution. Following imaging, the joints were scored from H&E stained sections for cartilage/bone erosion, pannus development, inflammation, and synovial hyperplasia. From micro-CT images, quantitative analysis of absolute bone volumes and bone roughness was performed. Bone erosion in the rat AA model is substantial, leading to a significant decline in tarsal volume (27%. The result of the custom bone roughness measurement indicated a 55% increase in surface roughness. Histological and paw volume analyses also demonstrated severe arthritic disease as compared to controls. Statistical analyses indicate correlations among bone volume, roughness, histology, and paw volume. These data demonstrate that the destructive progression of disease in a rat AA model can be quantified using 3-D micro-CT image analysis, which allows assessment of arthritic disease status and efficacy of experimental therapeutic agents.

  12. SU-F-R-33: Can CT and CBCT Be Used Simultaneously for Radiomics Analysis

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    Luo, R; Wang, J; Zhong, H; Gan, J; Hu, P; Shen, L; Hu, W; Zhang, Z [Fudan University Shanghai Cancer Center, Shanghai, Shanghai (China)

    2016-06-15

    Purpose: To investigate whether CBCT and CT can be used in radiomics analysis simultaneously. To establish a batch correction method for radiomics in two similar image modalities. Methods: Four sites including rectum, bladder, femoral head and lung were considered as region of interest (ROI) in this study. For each site, 10 treatment planning CT images were collected. And 10 CBCT images which came from same site of same patient were acquired at first radiotherapy fraction. 253 radiomics features, which were selected by our test-retest study at rectum cancer CT (ICC>0.8), were calculated for both CBCT and CT images in MATLAB. Simple scaling (z-score) and nonlinear correction methods were applied to the CBCT radiomics features. The Pearson Correlation Coefficient was calculated to analyze the correlation between radiomics features of CT and CBCT images before and after correction. Cluster analysis of mixed data (for each site, 5 CT and 5 CBCT data are randomly selected) was implemented to validate the feasibility to merge radiomics data from CBCT and CT. The consistency of clustering result and site grouping was verified by a chi-square test for different datasets respectively. Results: For simple scaling, 234 of the 253 features have correlation coefficient ρ>0.8 among which 154 features haveρ>0.9 . For radiomics data after nonlinear correction, 240 of the 253 features have ρ>0.8 among which 220 features have ρ>0.9. Cluster analysis of mixed data shows that data of four sites was almost precisely separated for simple scaling(p=1.29 * 10{sup −7}, χ{sup 2} test) and nonlinear correction (p=5.98 * 10{sup −7}, χ{sup 2} test), which is similar to the cluster result of CT data (p=4.52 * 10{sup −8}, χ{sup 2} test). Conclusion: Radiomics data from CBCT can be merged with those from CT by simple scaling or nonlinear correction for radiomics analysis.

  13. Temporal bone CT analysis of congenital ear anomalies

    International Nuclear Information System (INIS)

    Hwang, Jung Won; Moon, Min Joo; Sung, Kyu Bo

    1988-01-01

    Authors analysed the CT findings of the congenital ear anomalies of twenty-nine patients for 2 years and 3 months. The results were as follows: 1. Most of the patients were under the age of 20 (82.7%) and prevalent in male (72.4%). 2. Clinically, congenital ear anomalies were detected in 20 patients (68.9%), conductive hearing loss in 4, sensorineural hearing loss in 1, and the remained 4 patients were detected incidentally without clinical symptom. 3. In the cases of unilateral involvement of 20 patients, right ear was more common (12/20). Eight of 9 bilateral involvement showed similar degree. 4. The middle ear malformations were found in 22 patients (75.9%) and bilateral in 4 patients. 26 cases of middle ear malformations had been classified by Frey into 4 groups; Group I in 5, Group II in 9, Graoup III in 9 and Group IV in 3. 5. Incidentally found ear anomaly was lateral semicircular canal formed a single cavity with the vestibule in all patients (5 pts.). 6. Inner ear malformations accompanying sensorineural hearing loss were found in 3 patients with bilateral involvement and middle ear malformations were accompanied in 2 patients. The degree of involvement of labyrinth was variable.

  14. Systematic Review and Meta-Analysis of CT Features for Differentiating Complicated and Uncomplicated Appendicitis.

    Science.gov (United States)

    Kim, Hae Young; Park, Ji Hoon; Lee, Yoon Jin; Lee, Sung Soo; Jeon, Jong-June; Lee, Kyoung Ho

    2018-04-01

    Purpose To perform a systematic review and meta-analysis to identify computed tomographic (CT) features for differentiating complicated appendicitis in patients suspected of having appendicitis and to summarize their diagnostic accuracy. Materials and Methods Studies on diagnostic accuracy of CT features for differentiating complicated appendicitis (perforated or gangrenous appendicitis) in patients suspected of having appendicitis were searched in Ovid-MEDLINE, EMBASE, and the Cochrane Library. Overlapping descriptors used in different studies to denote the same image finding were subsumed under a single CT feature. Pooled diagnostic accuracy of the CT features was calculated by using a bivariate random effects model. CT features with pooled diagnostic odds ratios with 95% confidence intervals not including 1 were considered as informative. Results Twenty-three studies were included, and 184 overlapping descriptors for various CT findings were subsumed under 14 features. Of these, 10 features were informative for complicated appendicitis. There was a general tendency for these features to show relatively high specificity but low sensitivity. Extraluminal appendicolith, abscess, appendiceal wall enhancement defect, extraluminal air, ileus, periappendiceal fluid collection, ascites, intraluminal air, and intraluminal appendicolith showed pooled specificity greater than 70% (range, 74%-100%), but sensitivity was limited (range, 14%-59%). Periappendiceal fat stranding was the only feature that showed high sensitivity (94%; 95% confidence interval: 86%, 98%) but low specificity (40%; 95% confidence interval, 23%, 60%). Conclusion Ten informative CT features for differentiating complicated appendicitis were identified in this study, nine of which showed high specificity, but low sensitivity. © RSNA, 2017 Online supplemental material is available for this article.

  15. Verification of computed tomographic estimates of cochlear implant array position: a micro-CT and histologic analysis.

    Science.gov (United States)

    Teymouri, Jessica; Hullar, Timothy E; Holden, Timothy A; Chole, Richard A

    2011-08-01

    To determine the efficacy of clinical computed tomographic (CT) imaging to verify postoperative electrode array placement in cochlear implant (CI) patients. Nine fresh cadaver heads underwent clinical CT scanning, followed by bilateral CI insertion and postoperative clinical CT scanning. Temporal bones were removed, trimmed, and scanned using micro-CT. Specimens were then dehydrated, embedded in either methyl methacrylate or LR White resin, and sectioned with a diamond wafering saw. Histology sections were examined by 3 blinded observers to determine the position of individual electrodes relative to soft tissue structures within the cochlea. Electrodes were judged to be within the scala tympani, scala vestibuli, or in an intermediate position between scalae. The position of the array could be estimated accurately from clinical CT scans in all specimens using micro-CT and histology as a criterion standard. Verification using micro-CT yielded 97% agreement, and histologic analysis revealed 95% agreement with clinical CT results. A composite, 3-dimensional image derived from a patient's preoperative and postoperative CT images using a clinical scanner accurately estimates the position of the electrode array as determined by micro-CT imaging and histologic analyses. Information obtained using the CT method provides valuable insight into numerous variables of interest to patient performance such as surgical technique, array design, and processor programming and troubleshooting.

  16. Automated analysis for early signs of cerebral infarctions on brain X-ray CT images

    International Nuclear Information System (INIS)

    Oshima, Kazuki; Hara, Takeshi; Zhou, X.; Muramatsu, Chisako; Fujita, Hiroshi; Sakashita, Keiji

    2010-01-01

    t-PA (tissue plasminogen activator) thrombolysis is an effective clinical treatment for the acute cerebral infarction by breakdown to blood clots. However there is a risk of hemorrhage with its use. The guideline of the treatment is denying cerebral hemorrhage and widespread Early CT sign (ECS) on CT images. In this study, we analyzed the CT value of normal brain and ECS with normal brain model by comparing patient brain CT scan with a statistical normal model. Our method has constructed normal brain models consisted of 60 normal brain X-ray CT images. We calculated Z-score based on statistical model for 16 cases of cerebral infarction with ECS, 3 cases of cerebral infarction without ECS, and 25 cases of normal brain. The results of statistical analysis showed that there was a statistically significant difference between control and abnormal groups. This result implied that the automated detection scheme for ECS by using Z-score would be a possible application for brain computer-aided diagnosis (CAD). (author)

  17. Analysis of local concentration in stomach fold pattern by using abdominal X-ray CT image

    International Nuclear Information System (INIS)

    Watanabe, Shigeto; Hasegawa, Jun-ichi; Mekada, Yoshito; Mori, Kensaku; Nawano, Shigeru

    2004-01-01

    The paper presents a method for analysis of stomach folds pattern in abdominal X-ray CT images. Many stomach cancers have local concentration of folds at cancer lesions. Therefore, in stomach diagnosis, it is very important to evaluate quantitatively such fold concentration. In this paper, a method for calculation of concentration index for line figure on a curved surface is proposed first. Then, using this method a processing procedure for detection of stomach cancer from an abdominal X-ray CT image is developed. In the experiment using practical X-ray CT images, it is shown that by the proposed procedure, higher values of concentration index are obtained at cancer area. (author)

  18. Congenital TORCH infections of the brain--CT manifestation (with analysis of 7 cases)

    International Nuclear Information System (INIS)

    Li Xin; Li Minglin; Yang Zhiyong

    1997-01-01

    To study the neuropathologic changes and CT manifestations in congenital TORCH infection of the brain. Analysis of 7 cases of congenital TORCH infection of the neonates and infants demonstrated by serum examination was performed. There were congenital toxoplasmosis 3 cases, congenital syncytial virus infection 1 case, congenital rubella virus infection 1 case, congenital cytomegalovirus infection 2 cases, and congenital herpes simplex virus infection 1 case. Cerebral hypoplasia, ventricular dilatation or hydrocephalus, subependymal and parenchymal calcifications, microcephalic focal cortical migration anomalies, schizencephaly polymicrogyria, et al, were demonstrated by CT with congenital TORCH infection. The earlier the infection, the more severe the brain developmental anomalies. The extent and appearance of calcification in brain were related to the degree, extent and course of TORCH infection. Basal ganglia calcification of unknown cause in infant was suggestive of congenital TORCH infection. Typical CT manifestations together with clinical picture may suggest congenital TORCH infection, while serological test can be diagnostic

  19. CT analysis of lung cancer and coexistent emphysema

    International Nuclear Information System (INIS)

    Noh, Kyung Hee; Chung, Myung Hee; Sung, Mi Sook; Yoo, Won Jong; Son, Kyung Myung; Son, Jung Min; Park, Seog Hee

    2004-01-01

    To evaluate the relation of the location and cell type of lung cancer to the location and degree in coexistent emphysema on high-resolution computed tomography (HRCT) scans. Ninety-eight of 209 lung cancer patients having HRCT scans were retrospectively analyzed to assess the total lung emphysema and peritumoral regional emphysema. Single and primary lung cancers were included. The clinical data, including sex, age, smoking history and the pathologic cancer subtype, were recorded to correlate with the HRCT findings. The lobar distribution, central-peripheral predominance, surrounding parenchymal abnormality for cancer, cephalocaudal predominance, and subtype for emphysema were analyzed on HRCT. Using a CT scoring method, we scored the whole lung emphysema and peritumoral emphysema, and correlated the grading of emphysema with pulmonary functional values. Sixty-nine of 98 patients with lung cancer (71%) had emphysema. Lung cancer with emphysema was significantly higher in men than in women, and was significantly related to smoking. The mean age of cancer patients without emphysema was significantly lower than that of cancer patients with emphysema (68 yrs vs. 61 yrs, p= 0.0006). Emphysema of grade I (0-25%) was found in 52 cases, grade II (25-50%) in 15, and grade III (50-75%) in 2. Total emphysema score was paralleled to peritumoral emphysema score in 64.3%, while the remaining patients had a higher peritumoral emphysema score (grade II or III) than total emphysema score (grade 0 or I). There was no statistical correlation in the developmental location between the emphysema and the lung cancer (significant correlation was only noted in grade II group of total emphysema score). The incidence of non-small cell carcinoma tended to be higher than that of small cell carcinoma in the two groups. The possibility of lung cancer in patients with pulmonary nodule, coexisting emphysema, and especially in elderly patients having a history of smoking must be clarified on HRCT

  20. The cutting edge - Micro-CT for quantitative toolmark analysis of sharp force trauma to bone.

    Science.gov (United States)

    Norman, D G; Watson, D G; Burnett, B; Fenne, P M; Williams, M A

    2018-02-01

    Toolmark analysis involves examining marks created on an object to identify the likely tool responsible for creating those marks (e.g., a knife). Although a potentially powerful forensic tool, knife mark analysis is still in its infancy and the validation of imaging techniques as well as quantitative approaches is ongoing. This study builds on previous work by simulating real-world stabbings experimentally and statistically exploring quantitative toolmark properties, such as cut mark angle captured by micro-CT imaging, to predict the knife responsible. In Experiment 1 a mechanical stab rig and two knives were used to create 14 knife cut marks on dry pig ribs. The toolmarks were laser and micro-CT scanned to allow for quantitative measurements of numerous toolmark properties. The findings from Experiment 1 demonstrated that both knives produced statistically different cut mark widths, wall angle and shapes. Experiment 2 examined knife marks created on fleshed pig torsos with conditions designed to better simulate real-world stabbings. Eight knives were used to generate 64 incision cut marks that were also micro-CT scanned. Statistical exploration of these cut marks suggested that knife type, serrated or plain, can be predicted from cut mark width and wall angle. Preliminary results suggest that knives type can be predicted from cut mark width, and that knife edge thickness correlates with cut mark width. An additional 16 cut marks walls were imaged for striation marks using scanning electron microscopy with results suggesting that this approach might not be useful for knife mark analysis. Results also indicated that observer judgements of cut mark shape were more consistent when rated from micro-CT images than light microscopy images. The potential to combine micro-CT data, medical grade CT data and photographs to develop highly realistic virtual models for visualisation and 3D printing is also demonstrated. This is the first study to statistically explore simulated

  1. Colonic polyp detection method from 3D abdominal CT images based on local intensity analysis

    International Nuclear Information System (INIS)

    Oda, M.; Nakada, Y.; Kitasaka, T.; Mori, K.; Suenaga, Y.; Takayama, T.; Takabatake, H.; Mori, M.; Natori, H.; Nawano, S.

    2007-01-01

    This paper presents a detection method of colonic polyps from 3D abdominal CT images based on local intensity analysis. Recently, virtual colonoscopy (VC) has widely received attention as a new colon diagnostic method. VC is considered as a less-invasive inspection method which reduces patient load. However, since the colon has many haustra and its shape is long and convoluted, a physician has to change the viewpoint and the viewing direction of the virtual camera of VC many times while diagnosis. Additionally, there is a risk to overlook lesions existing in blinded areas caused by haustra. This paper proposes an automated colonic polyp detection method from 3D abdominal CT images. Colonic polyps are located on the colonic wall. Their CT values are higher than those of colonic lumen regions and lower than those of fecal materials tagged by an X-ray opaque contrast agent. CT values inside polyps which exist outside the tagged fecal materials tend to gradually increase from outward to inward (blob-like structure). CT values inside polyps that exist inside the tagged fecal materials tend to gradually decrease from outward to inward (inv-blob-like structure). We employ the blob and the inv-blob structure enhancement filters based on the eigenvalues of the Hessian matrix to detect polyps using intensity characteristic of polyps. Connected components with low output values of the enhancement filter are eliminated in false positive reduction process. Small connected components are also eliminated. We applied the proposed method to 44 cases of abdominal CT images. Sensitivity for polyps of 6 mm or larger was 80% with 4.7 false positives per case. (orig.)

  2. Analysis of diagnositc accuracy with CT-guided percutaneous transthoracic lung biopsy for pulmonary lesions

    International Nuclear Information System (INIS)

    Wang Haiyan; Zhuang Yiping; Zhang Jin; Feng Yong; Zhang Xiao; Xu Lin

    2007-01-01

    Objective: To evaluate the factors which may affect the diagnostic accmracy of CT-guided percutaneous transthoracic lung biopsy for pulmonary lesions. Methods: CT-guided percutaneous transthoracic lung biopsy was performed in 264 patients, all of which were proved by surgical pathology or clinical follow-up. A logistic regression analysis was used to investigate the relationship between the location and the size of the lesions and insertion depth of biopsy needles and the diagnostic accuracy of CT-guided percutaneous transthomcic lung biopsy. The complication rate including pneumatothorax and bleeding rate were record. Results: The diagnostic accuracy was 87.5%. Both the pneumothorax and the bleeding of lesion were 1.9%. The size of lesion was suggested by Logistic regression analysis had a significant influence on the diagnostic accuracy (Wald=12.891, P=0.00034, OR=0.96). Conclusion: CT-guided pereumneous transthoracic lung biopsy has a high diagnostic accuracy for pulmonary lesions. The size of the lesions had significant effect on the diagnostic accuracy. (authors)

  3. Meta-analysis: Serum creatinine changes following contrast enhanced CT imaging

    International Nuclear Information System (INIS)

    Kooiman, Judith; Pasha, Sharif M.; Zondag, Wendy; Sijpkens, Yvo W.J.; Molen, Aart J. van der; Huisman, Menno V.; Dekkers, Olaf M.

    2012-01-01

    Purpose: Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN. Materials and methods: A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach. Results: Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0–8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01–0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6–2.1%). Patients with chronic kidney disease (odds ratio 2.26, p < 0.001) or diabetes mellitus (odds ratio 3.10, p < 0.001) were at increased risk for the development of CIN. Conclusion: CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted

  4. Meta-analysis: Serum creatinine changes following contrast enhanced CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kooiman, Judith, E-mail: j.kooiman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Pasha, Sharif M., E-mail: s.m.pasha@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Zondag, Wendy, E-mail: w.zondag@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Sijpkens, Yvo W.J., E-mail: ysijpens@bronovo.nl [Department of Nephrology, Bronovo Hospital, The Hague (Netherlands); Molen, Aart J. van der, E-mail: molen@lumc.nl [Department of Radiology, LUMC, Leiden (Netherlands); Huisman, Menno V., E-mail: m.v.huisman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Dekkers, Olaf M., E-mail: o.m.dekkers@lumc.nl [Department of Clinical Epidemiology and Department of Endocrinology, LUMC, Leiden (Netherlands)

    2012-10-15

    Purpose: Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN. Materials and methods: A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach. Results: Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0–8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01–0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6–2.1%). Patients with chronic kidney disease (odds ratio 2.26, p < 0.001) or diabetes mellitus (odds ratio 3.10, p < 0.001) were at increased risk for the development of CIN. Conclusion: CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted.

  5. Quantitative analysis of titanium-induced artifacts and correlated factors during micro-CT scanning.

    Science.gov (United States)

    Li, Jun Yuan; Pow, Edmond Ho Nang; Zheng, Li Wu; Ma, Li; Kwong, Dora Lai Wan; Cheung, Lim Kwong

    2014-04-01

    To investigate the impact of cover screw, resin embedment, and implant angulation on artifact of microcomputed tomography (micro-CT) scanning for implant. A total of twelve implants were randomly divided into 4 groups: (i) implant only; (ii) implant with cover screw; (iii) implant with resin embedment; and (iv) implants with cover screw and resin embedment. Implants angulation at 0°, 45°, and 90° were scanned by micro-CT. Images were assessed, and the ratio of artifact volume to total volume (AV/TV) was calculated. A multiple regression analysis in stepwise model was used to determine the significance of different factors. One-way ANOVA was performed to identify which combination of factors could minimize the artifact. In the regression analysis, implant angulation was identified as the best predictor for artifact among the factors (P  0.05). Non-embedded implants with the axis parallel to X-ray source of micro-CT produced minimal artifact. Implant angulation and resin embedment affected the artifact volume of micro-CT scanning for implant, while cover screw did not. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Dual time point 18FDG-PET/CT versus single time point 18FDG-PET/CT for the differential diagnosis of pulmonary nodules - A meta-analysis

    International Nuclear Information System (INIS)

    Zhang, Li; Wang, Yinzhong; Lei, Junqiang; Tian, Jinhui; Zhai, Yanan

    2013-01-01

    Background: Lung cancer is one of the most common cancer types in the world. An accurate diagnosis of lung cancer is crucial for early treatment and management. Purpose: To perform a comprehensive meta-analysis to evaluate the diagnostic performance of dual time point 18F-fluorodexyglucose position emission tomography/computed tomography (FDG-PET/CT) and single time point 18FDG-PET/CT in the diagnosis of pulmonary nodules. Material and Methods: PubMed (1966-2011.11), EMBASE (1974-2011.11), Web of Science (1972-2011.11), Cochrane Library (-2011.11), and four Chinese databases; CBM (1978-2011.11), CNKI (1994-2011.11), VIP (1989-2011.11), and Wanfang Database (1994-2011.11) were searched. Summary sensitivity, summary specificity, summary diagnostic odds ratios (DOR), and summary positive likelihood ratios (LR+) and negative likelihood ratios (LR-) were obtained using Meta-Disc software. Summary receiver-operating characteristic (SROC) curves were used to evaluate the diagnostic performance of dual time point 18FDG-PET/CT and single time point 18FDG-PET/CT. Results: The inclusion criteria were fulfilled by eight articles, with a total of 415 patients and 430 pulmonary nodules. Compared with the gold standard (pathology or clinical follow-up), the summary sensitivity of dual time point 18FDG-PET/CT was 79% (95%CI, 74.0 - 84.0%), and its summary specificity was 73% (95%CI, 65.0-79.0%); the summary LR+ was 2.61 (95%CI, 1.96-3.47), and the summary LR- was 0.29 (95%CI, 0.21 - 0.41); the summary DOR was 10.25 (95%CI, 5.79 - 18.14), and the area under the SROC curve (AUC) was 0.8244. The summary sensitivity for single time point 18FDG-PET/CT was 77% (95%CI, 71.9 - 82.3%), and its summary specificity was 59% (95%CI, 50.6 - 66.2%); the summary LR+ was 1.97 (95%CI, 1.32 - 2.93), and the summary LR- was 0.37 (95%CI, 0.29 - 0.49); the summary DOR was 6.39 (95%CI, 3.39 - 12.05), and the AUC was 0.8220. Conclusion: The results indicate that dual time point 18FDG-PET/CT and single

  7. Ultra-low dose CT attenuation correction for PET/CT: analysis of sparse view data acquisition and reconstruction algorithms

    Science.gov (United States)

    Rui, Xue; Cheng, Lishui; Long, Yong; Fu, Lin; Alessio, Adam M.; Asma, Evren; Kinahan, Paul E.; De Man, Bruno

    2015-01-01

    For PET/CT systems, PET image reconstruction requires corresponding CT images for anatomical localization and attenuation correction. In the case of PET respiratory gating, multiple gated CT scans can offer phase-matched attenuation and motion correction, at the expense of increased radiation dose. We aim to minimize the dose of the CT scan, while preserving adequate image quality for the purpose of PET attenuation correction by introducing sparse view CT data acquisition. Methods We investigated sparse view CT acquisition protocols resulting in ultra-low dose CT scans designed for PET attenuation correction. We analyzed the tradeoffs between the number of views and the integrated tube current per view for a given dose using CT and PET simulations of a 3D NCAT phantom with lesions inserted into liver and lung. We simulated seven CT acquisition protocols with {984, 328, 123, 41, 24, 12, 8} views per rotation at a gantry speed of 0.35 seconds. One standard dose and four ultra-low dose levels, namely, 0.35 mAs, 0.175 mAs, 0.0875 mAs, and 0.04375 mAs, were investigated. Both the analytical FDK algorithm and the Model Based Iterative Reconstruction (MBIR) algorithm were used for CT image reconstruction. We also evaluated the impact of sinogram interpolation to estimate the missing projection measurements due to sparse view data acquisition. For MBIR, we used a penalized weighted least squares (PWLS) cost function with an approximate total-variation (TV) regularizing penalty function. We compared a tube pulsing mode and a continuous exposure mode for sparse view data acquisition. Global PET ensemble root-mean-squares-error (RMSE) and local ensemble lesion activity error were used as quantitative evaluation metrics for PET image quality. Results With sparse view sampling, it is possible to greatly reduce the CT scan dose when it is primarily used for PET attenuation correction with little or no measureable effect on the PET image. For the four ultra-low dose levels

  8. CT Texture Analysis of Ex Vivo Renal Stones Predicts Ease of Fragmentation with Shockwave Lithotripsy.

    Science.gov (United States)

    Cui, Helen W; Devlies, Wout; Ravenscroft, Samuel; Heers, Hendrik; Freidin, Andrew J; Cleveland, Robin O; Ganeshan, Balaji; Turney, Benjamin W

    2017-07-01

    Understanding the factors affecting success of extracorporeal shockwave lithotripsy (SWL) would improve informed decision-making on the most appropriate treatment modality for an individual patient. Although stone size and skin-to-stone distance do correlate with fragmentation efficacy, it has been shown that stone composition and architecture, as reflected by structural heterogeneity on CT, are also important factors. This study aims to determine if CT texture analysis (CTTA), a novel, nondestructive, and objective tool that generates statistical metrics reflecting stone heterogeneity, could have utility in predicting likelihood of SWL success. Seven spontaneously passed, intact renal tract stones, were scanned ex vivo using standard CT KUB and micro-CT. The stones were then fragmented in vitro using a clinical lithotripter, after which, chemical composition analysis was performed. CTTA was used to generate a number of metrics that were correlated to the number of shocks needed to fragment the stone. CTTA metrics reflected stone characteristics and composition, and predicted ease of SWL fragmentation. The strongest correlation with number of shocks required to fragment the stone was mean Hounsfield unit (HU) density (r = 0.806, p = 0.028) and a CTTA metric measuring the entropy of the pixel distribution of the stone image (r = 0.804, p = 0.039). Using multiple linear regression analysis, the best model showed that CTTA metrics of entropy and kurtosis could predict 92% of the outcome of number of shocks needed to fragment the stone. This was superior to using stone volume or density. CTTA metrics entropy and kurtosis have been shown in this experimental ex vivo setting to strongly predict fragmentation by SWL. This warrants further investigation in a larger clinical study for the contribution of CT textural metrics as a measure of stone heterogeneity, along with other known clinical factors, to predict likelihood of SWL success.

  9. Budd-Chiari syndrome: dynamic enhancement findings with multi-slice helical CT and CT angiography analysis

    International Nuclear Information System (INIS)

    Meng Xiaochun; Shan Hong; Zhu Kangshun; Xu Chuan; Zhang Jiansheng; Liu Lingyun; Ye Binbin

    2005-01-01

    Objective: To investigate the dynamic enhancement regulations of liver and their mechanism in Budd-Chiari syndrome (BCS) by using multi-slice CT and evaluate the value of CT angiography in the diagnosis of BCS. Methods: 28 cases with BCS confirmed by digital subtraction angiography (DSA) were retrospectively analyzed. All patients underwent dynamic enhancement examinations with multi-slice CT within 1 week before DSA. The relevant vessels were reconstructed respectively with MIP, VR and MPR. Compared with the results of DSA, we analyzed the dynamic enhancement regulations of liver in BCS, estimated the value of dynamic enhancement CT exams and CTA techniques in judging the obstruction level and showing collateral vessels. Results: Of all 28 cases, CT correctly showed the obstruction level in 26 cases, and 2 had incorrect results which proved to be membranous obstruction of the inferior vena cava superior to diaphragm. In 22 cases with hepatic vein obstructions, hepatic parenchyma displayed typical patchy enhancement in 19, atypical patchy enhancement in 3.8 cases among these showed benign nodules. Simultaneously, CT showed stenosis and rigidity of portal vein branches in 20, enlargement of hepatic artery in 14, hepatic collateral vessels in 20 out of 22 cases. In 6 cases with simple obstruction of inferior vena cava, hepatic changes were not found. Collateral circulations in or out of liver corresponded to the obstruction level. Conclusion: Dynamic enhancement examinations with multi-slice CT can correctly reflect the hepatic hemodynamic changes. Transverse images, combined with CTA, can explicitly display the obstruction level of vascular lesions and collateral circulations in BCS. (authors)

  10. An analysis of intraoperative versus post-operative dosimetry with CT, CT-MRI fusion and XMR for the evaluation of permanent prostate brachytherapy implants

    International Nuclear Information System (INIS)

    Acher, Peter; Puttagunta, Srikanth; Rhode, Kawal; Morris, Stephen; Kinsella, Janette; Gaya, Andrew; Dasgupta, Prokar; Deehan, Charles; Beaney, Ronald; Popert, Rick; Keevil, Stephen

    2010-01-01

    Background and purpose: To assess the agreement between intraoperative and post-operative dosimetry and to identify factors that influence dose calculations of prostate brachytherapy implants. Materials and methods: Patients treated with prostate brachytherapy implants underwent post-operative CT and XMR (combined X-ray and MR) imaging. Dose-volume histograms were calculated from CT, XMR and CT-MR fusion data and compared with intraoperative values for two observers. Multiple linear regression models assessed the influences of intraoperative D90, gland oedema, gland volume, source loss and migration, and implanted activity/volume prostate on post-operative D90. Results: Forty-nine patients were studied. The mean D90 differences (95% confidence limits) between intraoperative and post-operative CT, XMR and CT-MR fusion assessments were: 11 Gy (-22, 45), 18 Gy (-13, 49) and 20 Gy (-17, 58) for Observer 1; and 15 Gy (-34, 63), 13 Gy (-29, 55) and 14 Gy (-27, 54) for Observer 2. Multiple linear regression modelling showed that the observed oedema and intraoperative D90 were significant independent variables for the prediction of post-operative D90 values for both observers using all modalities. Conclusion: This is the first study to report Bland-Altman agreement analysis between intraoperative and post-operative dosimetry. Agreement is poor. Post-operative dosimetry is dependent on the intraoperative D90 and the subjectively outlined gland volume.

  11. Detailed analysis of the density change on chest CT of COPD using non-rigid registration of inspiration/expiration CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Young [Chonbuk National University Medical School and Hospital, Research Institute of Clinical Medicine, Department of Radiology, Jeollabuk-do (Korea, Republic of); University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Seo, Joon Beom; Lee, Hyun Joo; Kim, Namkug; Lee, Eunsol; Lee, Sang Min; Oh, Sang Young [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Hwang, Hye Jeon [Hallym University Sacred Heart Hospital, Department of Radiology, Hallym University College of Medicine, Gyeonggi-do (Korea, Republic of); Oh, Yeon-Mok; Lee, Sang-Do [University of Ulsan College of Medicine, Asan Medical Center, Department of Pulmonary and Critical Care Medicine, and Clinical Research Center for Chronic Obstructive Airway Diseases, Seoul (Korea, Republic of)

    2014-09-14

    One objective was to evaluate the air trapping index (ATI), measured by inspiration/expiration CT, in COPD patients and nonsmokers. Another objective was to assess the association between the pulmonary function test (PFT) and CT parameters such as ATI or other indices, separately in the whole lung, in emphysema, and in hyperinflated and normal lung areas. One hundred and thirty-eight COPD patients and 29 nonsmokers were included in our study. The ATI, the emphysema index (EI), the gas trapping index (Exp -856) and expiration/inspiration ratio of mean lung density (E/Iratio of MLD) were measured on CT. The values of the whole lung, of emphysema, and of hyperinflated and normal lung areas were compared and then correlated with various PFT parameters. Compared with nonsmokers, COPD patients showed a higher ATI in the whole lung and in each lung lesion (all P < 0.05). The ATI showed a higher correlation than EI with FEF{sub 25-75%}, RV and RV/TLC, and was comparable to Exp -856 and the E/I ratio of MLD. The ATI of emphysema and hyperinflated areas on CT showed better correlation than the normal lung area with PFT parameters. Detailed analysis of density change at inspiration and expiration CT of COPD can provide new insights into pulmonary functional impairment in each lung area. (orig.)

  12. Detailed analysis of the density change on chest CT of COPD using non-rigid registration of inspiration/expiration CT scans

    International Nuclear Information System (INIS)

    Kim, Eun Young; Seo, Joon Beom; Lee, Hyun Joo; Kim, Namkug; Lee, Eunsol; Lee, Sang Min; Oh, Sang Young; Hwang, Hye Jeon; Oh, Yeon-Mok; Lee, Sang-Do

    2015-01-01

    One objective was to evaluate the air trapping index (ATI), measured by inspiration/expiration CT, in COPD patients and nonsmokers. Another objective was to assess the association between the pulmonary function test (PFT) and CT parameters such as ATI or other indices, separately in the whole lung, in emphysema, and in hyperinflated and normal lung areas. One hundred and thirty-eight COPD patients and 29 nonsmokers were included in our study. The ATI, the emphysema index (EI), the gas trapping index (Exp -856) and expiration/inspiration ratio of mean lung density (E/Iratio of MLD) were measured on CT. The values of the whole lung, of emphysema, and of hyperinflated and normal lung areas were compared and then correlated with various PFT parameters. Compared with nonsmokers, COPD patients showed a higher ATI in the whole lung and in each lung lesion (all P 25-75% , RV and RV/TLC, and was comparable to Exp -856 and the E/I ratio of MLD. The ATI of emphysema and hyperinflated areas on CT showed better correlation than the normal lung area with PFT parameters. Detailed analysis of density change at inspiration and expiration CT of COPD can provide new insights into pulmonary functional impairment in each lung area. (orig.)

  13. Quantitative CT analysis of pulmonary pure ground-glass nodule predicts histological invasiveness

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qiong, E-mail: liqiongsmmu2008@qq.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China); Fan, Li, E-mail: fanli0930@163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China); Cao, En-Tao, E-mail: cet123cs@126.com [Department of Radiology, Suzhou Municipal Hospital (East District), No.16 West Baita Road, Suzhu, Jiangsu Province 215001 (China); Li, Qing-Chu, E-mail: Wudi327@hotmail.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China); Gu, Ya-Feng, E-mail: 2528473557@qq.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China); Liu, Shi−Yuan, E-mail: liusy1186@163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China)

    2017-04-15

    Objective: To assess whether quantitative computed tomography (CT) can help predict histological invasiveness of pulmonary adenocarcinoma appearing as pure ground glass nodules (pGGNs). Methods: A total of 110 pulmonary pGGNs were retrospectively evaluated, and pathologically classified as pre-invasive lesions, minimally invasive adenocarcinoma (MIA) and invasive pulmonary adenocarcinoma (IPA). Maximum nodule diameters, largest cross-sectional areas, volumes, mean CT values, weights, and CT attenuation values at the 0th,2th,5th, 25th, 50th,75th, 95th, 98th and100th percentiles on histogram, as well as 2th to 98th, 5th to 95th, 25th to 75th,and 0th to 100thslopes, respectively, were compared among the three groups. Results: Of the 110 pGGNs, 50, 28, and 32 were pre-invasive lesions, MIA, and IPA, respectively. Maximum nodule diameters, largest cross-sectional areas, andmass weights were significantly larger in the IPA group than in pre-invasive lesions. The 95th, 98th, 100th percentiles, and 2th to 98th, 25th to 75th, and 0th to 100thslopes were significantly different between pre-invasive lesions and MIA or IPA. Logistic regression analysis showed that the maximum nodule diameter (OR = 1.21, 95%CI: 1.071–1.366, p < 0.01) and 100th percentile on histogram (OR = 1.02, 95%CI: 1.009–1.032, p < 0.001) independently predicted histological invasiveness. Conclusions: Quantitative analysis of CT imaging can predict histological invasiveness of pGGNs, especiallythe maximum nodule diameter and 100th percentile on CT number histogram; this can instruct the long-term follow-up and selective surgical management.

  14. Crackle analysis for chest auscultation and comparison with high-resolution CT findings.

    Science.gov (United States)

    Kawamura, Takeo; Matsumoto, Tsuneo; Tanaka, Nobuyuki; Kido, Shoji; Jiang, Zhongwei; Matsunaga, Naofumi

    2003-01-01

    The purpose of our study was to clarify the correlation between respiratory sounds and the high-resolution CT (HRCT) findings of lung diseases. Respiratory sounds were recorded using a stethoscope in 41 patients with crackles. All had undergone inspiratory and expiratory CT. Subjects included 18 patients with interstitial pneumonia and 23 without interstitial pneumonia. Two parameters, two-cycle duration (2CD) and initial deflection width (IDW) of the "crackle," were induced by time-expanded waveform analysis. Two radiologists independently assessed 11 HRCT findings. An evaluation was carried out to determine whether there was a significant difference in the two parameters between the presence and absence of each HRCT finding. The two parameters of crackles were significantly shorter in the interstitial pneumonia group than the non-interstitial pneumonia group. Ground-glass opacity, honeycombing, lung volume reduction, traction bronchiectasis, centrilobular nodules, emphysematous change, and attenuation and volume change between inspiratory and expiratory CT were correlated with one or two parameters in all patients, whereas the other three findings were not. Among the interstitial pneumonia group, traction bronchiectasis, emphysematous change, and attenuation and volume change between inspiratory and expiratory CT were significantly correlated with one or two parameters. Abnormal respiratory sounds were correlated with some HRCT findings.

  15. Crackle analysis for chest auscultation and comparison with high-resolution CT findings

    International Nuclear Information System (INIS)

    Kawamura, Takeo; Matsumoto, Tsuneo; Tanaka, Nobuyuki; Matsunaga, Naofumi; Kido, Shoji; Jiang Zhongwei

    2003-01-01

    The purpose of our study was to clarify the correlation between respiratory sounds and the high-resolution CT (HRCT) findings of lung diseases. Respiratory sounds were recorded using a stethoscope in 41 patients with crackles. All had undergone inspiratory and expiratory CT. Subjects included 18 patients with interstitial pneumonia and 23 without interstitial pneumonia. Two parameters, two-cycle duration (2CD) and initial deflection width (IDW) of the ''crackle,'' were induced by time-expanded waveform analysis. Two radiologists independently assessed 11 HRCT findings. An evaluation was carried out to determine whether there was a significant difference in the two parameters between the presence and absence of each HRCT finding. The two parameters of crackles were significantly shorter in the interstitial pneumonia group than the non-interstitial pneumonia group. Ground-glass opacity, honeycombing, lung volume reduction, traction bronchiectasis, centrilobular nodules, emphysematous change, and attenuation and volume change between inspiratory and expiratory CT were correlated with one or two parameters in all patients, whereas the other three findings were not. Among the interstitial pneumonia group, traction bronchiectasis, emphysematous change, and attenuation and volume change between inspiratory and expiratory CT were significantly correlated with one or two parameters. Abnormal respiratory sounds were correlated with some HRCT findings. (author)

  16. Statistical analysis of CT brain scans in the evaluation of cerebral atrophy and hydrocephalus

    International Nuclear Information System (INIS)

    Oberthur, J.; Baddeley, H.; Jayasinghe, L.; Walsh, P.

    1983-01-01

    All the subjects with a visual CT diagnosis of atrophy or hydrocephalus showed variations from the normal in excess of two standard deviations so the standard deviation analysis method can be regarded as being as sensitive as the visual interpretation. However, three patients in the control group were also indicted although their results were only in the borderline range. Limitations of the study are discussed

  17. A study on quantifying COPD severity by combining pulmonary function tests and CT image analysis

    Science.gov (United States)

    Nimura, Yukitaka; Kitasaka, Takayuki; Honma, Hirotoshi; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi; Mori, Kensaku

    2011-03-01

    This paper describes a novel method that can evaluate chronic obstructive pulmonary disease (COPD) severity by combining measurements of pulmonary function tests and measurements obtained from CT image analysis. There is no cure for COPD. However, with regular medical care and consistent patient compliance with treatments and lifestyle changes, the symptoms of COPD can be minimized and progression of the disease can be slowed. Therefore, many diagnosis methods based on CT image analysis have been proposed for quantifying COPD. Most of diagnosis methods for COPD extract the lesions as low-attenuation areas (LAA) by thresholding and evaluate the COPD severity by calculating the LAA in the lung (LAA%). However, COPD is usually the result of a combination of two conditions, emphysema and chronic obstructive bronchitis. Therefore, the previous methods based on only LAA% do not work well. The proposed method utilizes both of information including the measurements of pulmonary function tests and the results of the chest CT image analysis to evaluate the COPD severity. In this paper, we utilize a multi-class AdaBoost to combine both of information and classify the COPD severity into five stages automatically. The experimental results revealed that the accuracy rate of the proposed method was 88.9% (resubstitution scheme) and 64.4% (leave-one-out scheme).

  18. High prevalence of bronchiectasis in adults. Analysis of CT findings in a health screening program

    International Nuclear Information System (INIS)

    Kwak, Hyun-Jung; Moon, Ji-Yong; Choi, Vo-Won; Kim, Tae-Hyung; Sohn, Jang-Won; Yoon, Ho-Joo; Shin, Dong-Ho; Park, Sung-Soo; Kim, Sang-Heon

    2010-01-01

    Bronchiectasis is one of the common chronic respiratory diseases and associated with respiratory morbidity and mortality. However, neither its prevalence nor its etiology is well-defined. We aimed to estimate the prevalence and risk factors of bronchiectasis in adults. In a retrospective study, we analyzed radiologic findings on chest computed tomography (CT) images performed as part of a health-screening program. From January to December 2008, 1,409 (24.6%) of 5,727 participants in the screening program of a health promotion center at a university hospital underwent chest CT scans based on the subject's decision. Bronchiectasis was diagnosed, if there was abnormal bronchial dilatation in any area of both lungs on chest CT. Respiratory symptoms, smoking status, and past medical history were also analyzed to define clinical characteristics and risk factors of bronchiectasis. Of 1,409 patients (aged 23-86 years), who were screened for respiratory diseases using chest CT for one year in a health promotion center, 129 patients (9.1%) were diagnosed with bronchiectasis. The prevalence of bronchiectasis was higher in females than in males (11.5% vs. 7.9%, p=0.022) and increased with age. Respiratory symptoms were reported in 53.7% of subjects. Previous history of tuberculosis (TB) (odds ratio (OR) 4.61, 95% confidence interval (Cl) 2.39-8.88, p=0.001) and age (OR 2.49, 95% Cl 1.56-3.98, p=0.001) were significantly associated with bronchiectasis. This retrospective analysis of chest CT findings in health screening examinees revealed a very high prevalence of bronchiectasis in adults. Previous TB infection is one of the major causes of bronchiectasis. (author)

  19. Multidetector row CT of the brain and carotid artery: a correlative analysis

    International Nuclear Information System (INIS)

    Saba, L.; Montisci, R.; Sanfilippo, R.; Mallarini, G.

    2009-01-01

    Aim: To evaluate the association between types of carotid plaque, the presence of prior ischaemic events detectable with CT, and patient's symptoms. Materials and methods: Between January 2004 and May 2006, 112 patients were evaluated using multidetector row computed tomography angiography (MDCTA) of the carotid arteries and computed tomography (CT) of the brain. Carotid arteries were categorized by evaluating the degree of stenosis according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria, the type of plaque, and the presence of plaque ulceration. The brain was assessed via CT for the presence, type, and position of lesions. Chi-square tests, Student's t test, and simple logistic regression analysis were performed and the Cohen kappa test was applied for interobserver variability measurement. Results: The Chi-square test indicated a statistically significant association between the presence of fatty plaques (p = 0.005) and CT-detectable lesions in the brain (p = 0.004). Moreover, the number of patients with CT-detectable brain lesions was greater in patients with >70% stenosis than in those with 70% stenosis and symptoms (p = 0.041), and an inverse association between calcified plaque and symptoms (p = 0.009). Conclusion: MDCTA allows adequate evaluation of the type of plaque. The results of the present study indicate that there is an association between cerebral lesions, symptoms, and fatty plaque in the carotid artery. The degree of stenosis also correlated with cerebral lesions and symptoms. According to the obtained data, the type of carotid plaque should be included among primary parameters in the classification of patients' risk class.

  20. Significance of CT analysis of regional lymph node metastases in colorectal cancer; Bedeutung der CT fuer die Beurteilung regionaerer Lymphknotenmetastasen bei kolorektalen Karzinomen

    Energy Technology Data Exchange (ETDEWEB)

    Gomille, T.; Christ, F. [Duesseldorf Univ. (Germany). Abt. fuer Radiologie und Nuklearmedizin; Aleksic, M.; Ulrich, B. [Krankenhaus Gerresheim (Germany). Chirurgische Klinik

    1998-12-01

    Purpose: For preoperative staging of colorectal cancer a CT scan is frequently performed. This report examines the sensitivity of CT for regional lymph node metastasis of colorectal cancer using different criteria. Materials and methods: Preoperative CT scans of 153 patients with colorectal cancer were analyzed using different criteria for N1. The results were then compared to the postoperative histological findings. Results: For N1=lymph nodes (LN)>1 cm the sensitivity was 47%. For N1=LN>1 cm or an increased number of LN<1 cm the sensitivity was 71%. In patients with a primary tumor seen on CT, sensitivity rose to 87%. Discussion: Evidence of regional nodal metastatic disease is only relevant for rectal cancer, colon polyps, and for locally excised tumors when considering present surgical concepts for the treatment of colorectal cancer. In these cases CT analysis using the broadened criteria for N1 proposes a valuable argument regarding possible preoperative radiotherapy or an operative revision. (orig.) [Deutsch] Die Sensitivitaet fuer den Nachweis regionaerer Lymphknotenmetastasen kolorektaler Karzinome wurde unter Anwendung verschiedener Kriterien fuer das N1-Stadium an Patienten mit histologisch gesichertem Lymphknotenbefund untersucht. Fuer das Kriterium N1=Lymphknoten (LK)>1 cm betrug die Sensitivitaet 47%. Fuer N1=LK>1 cm/vermehrte Anzahl LK<1 cm war sie 71%, bei erkennbarem Primaertumor sogar 87%. Unter Beruecksichtigung der derzeit geltenden operativen Therapiekonzepte ist der Nachweis von regionaeren Lymphknotenmetastasen nur bei Rektumkarzinom bzw. fuer Kolonpolypen oder fuer lokal exzidierte Karzinome fuer das therapeutische Vorgehen relevant. In diesen Faellen leistet die CT mit den erweiterten Kriterien fuer ein N1-Stadium trotz hoeherer falsch-positiver Raten eine wertvolle Hilfestellung fuer die Entscheidung ueber eine neoadjuvante Bestrahlung oder eine Nachresektion. (orig.)

  1. Morphometric analysis of the femur in cerebral palsy: 3-dimensional CT study.

    Science.gov (United States)

    Gose, Shinichi; Sakai, Takashi; Shibata, Toru; Murase, Tsuyoshi; Yoshikawa, Hideki; Sugamoto, Kazuomi

    2010-09-01

    =-0.25), or between the neck-shaft angle and the femoral anteversion (r=0.23). The neck-shaft angle, the femoral anteversion, and the CT migration percentage were significantly larger, and the femoral offset was significantly smaller, in patients with the Gross Motor Functional Classification System (GMFCS) level IV/V (nonwalking children) and SQ type, than in patients with GMFCS level II/III (mostly walking children) and SD type. The 3-dimensional femoral geometry in CP patients can be analyzed quantitatively using 3D-CT regardless of the abnormal spastic posture. Our data indicate that 3-dimensional evaluation is accurate and useful for analysis of the femur and acetabulum in CP, and that the extent of coxa valga and femoral anteversion is more severe in the patients with GMFCS level IV/V and SQ type. Level IV.

  2. Application of 3D X-ray CT data sets to finite element analysis

    International Nuclear Information System (INIS)

    Bossart, P.L.; Martz, H.E.; Brand, H.R.; Hollerbach, K.

    1995-01-01

    Finite Element Modeling (FEM) is becoming more important as industry drives toward concurrent engineering. A fundamental hindrance to fully exploiting the power of FEM is the human effort required to acquire complex part geometry, particularly as-built geometry, as a FEM mesh. Many Quantitative Non Destructive Evaluation (QNDE) techniques that produce three-dimensional (3D) data sets provide a substantial reduction in the effort required to apply FEM to as-built parts. This paper describes progress at LLNL on the application of 3D X-ray computed tomography (CT) data sets to more rapidly produce high-quality FEM meshes of complex, as-built geometries. Issues related to the volume segmentation of the 3D CT data as well as the use of this segmented data to tailor generic hexahedral FEM meshes to part specific geometries are discussed. The application of these techniques to FEM analysis in the medical field is reported here

  3. Biomechanical analysis of scoliosis and back muscles using CT evaluation and finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Saka, K

    1987-03-01

    The CT observation of back muscles of an idiopathic scoliosis patient showed increased muscle volume and high CT value on the convex side. Following these muscles by digitizer showed that convex muscle volume increased as the vertebra shifted to convexity. These back muscles were suggested to be transversospinalis muscles. Biomechanical analysis using finite element method (FEM) was done to further investigate this increasing volume of back muscles. A Risser experiment using FEM revealed that initial lordosis configuration model only produces rotation to the convex side by unilateral loading. We, therefore, made the model adding posterior element, regarding contraction of M. transversospinalis. In a normal case, the upper vertebra is rotated over the lower towards the side opposite the muscle contraction. The scoliosis model, however, showed rotation towards the side of muscle contraction. M. transversospinalis can be considered as the agent of this rotation force. In a rib cage model, M. transversospinalis also affected the rib cage deformity.

  4. Biomechanical analysis of scoliosis and back muscles using CT evaluation and finite element method

    International Nuclear Information System (INIS)

    Saka, Kenji

    1987-01-01

    The CT observation of back muscles of an idiopathic scoliosis patient showed increased muscle volume and high CT value on the convex side. Following these muscles by digitizer showed that convex muscle volume increased as the vertebra shifted to convexity. These back muscles were suggested to be transversospinalis muscles. Biomechanical analysis using finite element method (FEM) was done to further investigate this increasing volume of back muscles. A Risser experiment using FEM revealed that initial lordosis configuration model only produces rotation to the convex side by unilateral loading. We, therefore, made the model adding posterior element, regarding contraction of M. transversospinalis. In a normal case, the upper vertebra is rotated over the lower towards the side opposite the muscle contraction. The scoliosis model, however, showed rotation towards the side of muscle contraction. M. transversospinalis can be considered as the agent of this rotation force. In a rib cage model, M. transversospinalis also affected the rib cage deformity. (author)

  5. Automatic computer aided analysis algorithms and system for adrenal tumors on CT images.

    Science.gov (United States)

    Chai, Hanchao; Guo, Yi; Wang, Yuanyuan; Zhou, Guohui

    2017-12-04

    The adrenal tumor will disturb the secreting function of adrenocortical cells, leading to many diseases. Different kinds of adrenal tumors require different therapeutic schedules. In the practical diagnosis, it highly relies on the doctor's experience to judge the tumor type by reading the hundreds of CT images. This paper proposed an automatic computer aided analysis method for adrenal tumors detection and classification. It consisted of the automatic segmentation algorithms, the feature extraction and the classification algorithms. These algorithms were then integrated into a system and conducted on the graphic interface by using MATLAB Graphic user interface (GUI). The accuracy of the automatic computer aided segmentation and classification reached 90% on 436 CT images. The experiments proved the stability and reliability of this automatic computer aided analytic system.

  6. Comparison of MRI-based and CT/MRI fusion-based postimplant dosimetric analysis of prostate brachytherapy

    International Nuclear Information System (INIS)

    Tanaka, Osamu; Hayashi, Shinya; Matsuo, Masayuki; Sakurai, Kota; Nakano, Masahiro; Maeda, Sunaho; Kajita, Kimihiro R.T.; Deguchi, Takashi; Hoshi, Hiroaki

    2006-01-01

    Purpose: The aim of this study was to compare the outcomes between magnetic resonance imaging (MRI)-based and computed tomography (CT)/MRI fusion-based postimplant dosimetry methods in permanent prostate brachytherapy. Methods and Materials: Between October 2004 and March 2006, a total of 52 consecutive patients with prostate cancer were treated by brachytherapy, and postimplant dosimetry was performed using CT/MRI fusion. The accuracy and reproducibility were prospectively compared between MRI-based dosimetry and CT/MRI fusion-based dosimetry based on the dose-volume histogram (DVH) related parameters as recommended by the American Brachytherapy Society. Results: The prostate volume was 15.97 ± 6.17 cc (mean ± SD) in MRI-based dosimetry, and 15.97 ± 6.02 cc in CT/MRI fusion-based dosimetry without statistical difference. The prostate V100 was 94.5% and 93.0% in MRI-based and CT/MRI fusion-based dosimetry, respectively, and the difference was statistically significant (p = 0.002). The prostate D90 was 119.4% and 114.4% in MRI-based and CT/MRI fusion-based dosimetry, respectively, and the difference was statistically significant (p = 0.004). Conclusion: Our current results suggested that, as with fusion images, MR images allowed accurate contouring of the organs, but they tended to overestimate the analysis of postimplant dosimetry in comparison to CT/MRI fusion images. Although this MRI-based dosimetric discrepancy was negligible, MRI-based dosimetry was acceptable and reproducible in comparison to CT-based dosimetry, because the difference between MRI-based and CT/MRI fusion-based results was smaller than that between CT-based and CT/MRI fusion-based results as previously reported

  7. Pancreatic invasion of gastric carcinoma in emaciated patients: The value of combined analysis with CT and upper gastrointestinal series

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Mun; Kim, Hyun; Kim, Choon Yul; Bahk, Yong Whee [Catholic University Medical College, Seoul (Korea, Republic of)

    1992-03-15

    The obliteration of a fat plane between the gastric carcinoma and the pancreas is a major criterion on CT scan for pancreatic invasion of gastric carcinoma. However, this sign is not always a reliable indicator of invasion, as the patients with gastric carcinoma are often emaciated, producing a false positive CT findings. The purpose of our study is to improve the diagnostic accuracy of pancreatic invasion of gastric carcinoma in cases which the fat plane between the gastric carcinoma and the pancreas is obliterated in conventional CT scan. The authors performed lateral decubitus as well as supine CT scans and upper gastrointestinal series(UGIS) in 49 pathologically proven cases in which the fat plane was obliterated between the gastric carcinoma and the pancreas on conventional supine CT scan. Pancreatic invasion was suggested when the fat plane was obliterated persistently in the lateral decubitus view as well as the spine CT images and the involved gastric wall and adjacent pancreas maintained constant approximation despite postural change(CT+), and when the gastric tumor moved downward on the erect view of the UGIS no more than 1.5 times the height of the first lumbar vertebral body(UGIS+). Among 49 cases in which the fat plane between the gastric carcinoma and the pancreas was obliterated on supine CT scan, pancreatic invasion was confirmed pathologically in 11 cases(22.4%). Eight of 11 cases proven as pancreatic invasion were correctly diagnosed as pancreatic invasion by this combined analysis(CT+/UGIS+, 72.7%). Twenty seven of 38 cases proven as no pancreatic invasion were correctly diagnosed as no pancreatic invasion(CT-/UGIS-, 71.1%). Twelve cases showed CT+/UGIS- or CT-/UGIS+, so it was inconclusive whether there was invasion or not. The overall diagnostic accuracy was 71.4%. In conclusion, combined analysis with supine and lateral decubitus CT and UGIS is useful for improving diagnostic accuracy for pancreatic invasion by gastric carcinoma in patients of

  8. Pancreatic invasion of gastric carcinoma in emaciated patients: The value of combined analysis with CT and upper gastrointestinal series

    International Nuclear Information System (INIS)

    Lee, Jae Mun; Kim, Hyun; Kim, Choon Yul; Bahk, Yong Whee

    1992-01-01

    The obliteration of a fat plane between the gastric carcinoma and the pancreas is a major criterion on CT scan for pancreatic invasion of gastric carcinoma. However, this sign is not always a reliable indicator of invasion, as the patients with gastric carcinoma are often emaciated, producing a false positive CT findings. The purpose of our study is to improve the diagnostic accuracy of pancreatic invasion of gastric carcinoma in cases which the fat plane between the gastric carcinoma and the pancreas is obliterated in conventional CT scan. The authors performed lateral decubitus as well as supine CT scans and upper gastrointestinal series(UGIS) in 49 pathologically proven cases in which the fat plane was obliterated between the gastric carcinoma and the pancreas on conventional supine CT scan. Pancreatic invasion was suggested when the fat plane was obliterated persistently in the lateral decubitus view as well as the spine CT images and the involved gastric wall and adjacent pancreas maintained constant approximation despite postural change(CT+), and when the gastric tumor moved downward on the erect view of the UGIS no more than 1.5 times the height of the first lumbar vertebral body(UGIS+). Among 49 cases in which the fat plane between the gastric carcinoma and the pancreas was obliterated on supine CT scan, pancreatic invasion was confirmed pathologically in 11 cases(22.4%). Eight of 11 cases proven as pancreatic invasion were correctly diagnosed as pancreatic invasion by this combined analysis(CT+/UGIS+, 72.7%). Twenty seven of 38 cases proven as no pancreatic invasion were correctly diagnosed as no pancreatic invasion(CT-/UGIS-, 71.1%). Twelve cases showed CT+/UGIS- or CT-/UGIS+, so it was inconclusive whether there was invasion or not. The overall diagnostic accuracy was 71.4%. In conclusion, combined analysis with supine and lateral decubitus CT and UGIS is useful for improving diagnostic accuracy for pancreatic invasion by gastric carcinoma in patients of

  9. Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis

    International Nuclear Information System (INIS)

    Jin, H.; Yuan, L.; Li, C.; Kan, Y.; Yang, J.; Hao, R.

    2014-01-01

    The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

  10. Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis.

    Science.gov (United States)

    Jin, H; Yuan, L; Li, C; Kan, Y; Hao, R; Yang, J

    2014-03-01

    The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

  11. Complication rates of CT-guided transthoracic lung biopsy: meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Heerink, W.J.; Vliegenthart, R. [University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, University of Groningen, Groningen (Netherlands); University Medical Center Groningen, Department of Radiology, University of Groningen, Groningen (Netherlands); Bock, G.H. de [University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, University of Groningen, Groningen (Netherlands); University Medical Center Groningen, Department of Epidemiology, University of Groningen, Groningen (Netherlands); Jonge, G.J. de [University Medical Center Groningen, Department of Radiology, University of Groningen, Groningen (Netherlands); Groen, H.J.M. [University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, University of Groningen, Groningen (Netherlands); University Medical Center Groningen, Department of Pulmonary Medicine, University of Groningen, Groningen (Netherlands); Oudkerk, M. [University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, University of Groningen, Groningen (Netherlands)

    2017-01-15

    To meta-analyze complication rate in computed tomography (CT)-guided transthoracic lung biopsy and associated risk factors. Four databases were searched from 1/2000 to 8/2015 for studies reporting complications in CT-guided lung biopsy. Overall and major complication rates were pooled and compared between core biopsy and fine needle aspiration (FNA) using the random-effects model. Risk factors for complications in core biopsy and FNA were identified in meta-regression analysis. For core biopsy, 32 articles (8,133 procedures) were included and for FNA, 17 (4,620 procedures). Pooled overall complication rates for core biopsy and FNA were 38.8 % (95 % CI: 34.3-43.5 %) and 24.0 % (95 % CI: 18.2-30.8 %), respectively. Major complication rates were 5.7 % (95 % CI: 4.4-7.4 %) and 4.4 % (95 % CI: 2.7-7.0 %), respectively. Overall complication rate was higher for core biopsy compared to FNA (p < 0.001). For FNA, larger needle diameter was a risk factor for overall complications, and increased traversed lung parenchyma and smaller lesion size were risk factors for major complications. For core biopsy, no significant risk factors were identified. In CT-guided lung biopsy, minor complications were common and occurred more often in core biopsy than FNA. Major complication rate was low. For FNA, smaller nodule diameter, larger needle diameter and increased traversed lung parenchyma were risk factors for complications. (orig.)

  12. Material Science Image Analysis using Quant-CT in ImageJ

    Energy Technology Data Exchange (ETDEWEB)

    Ushizima, Daniela M.; Bianchi, Andrea G. C.; DeBianchi, Christina; Bethel, E. Wes

    2015-01-05

    We introduce a computational analysis workflow to access properties of solid objects using nondestructive imaging techniques that rely on X-ray imaging. The goal is to process and quantify structures from material science sample cross sections. The algorithms can differentiate the porous media (high density material) from the void (background, low density media) using a Boolean classifier, so that we can extract features, such as volume, surface area, granularity spectrum, porosity, among others. Our workflow, Quant-CT, leverages several algorithms from ImageJ, such as statistical region merging and 3D object counter. It also includes schemes for bilateral filtering that use a 3D kernel, for parallel processing of sub-stacks, and for handling over-segmentation using histogram similarities. The Quant-CT supports fast user interaction, providing the ability for the user to train the algorithm via subsamples to feed its core algorithms with automated parameterization. Quant-CT plugin is currently available for testing by personnel at the Advanced Light Source and Earth Sciences Divisions and Energy Frontier Research Center (EFRC), LBNL, as part of their research on porous materials. The goal is to understand the processes in fluid-rock systems for the geologic sequestration of CO2, and to develop technology for the safe storage of CO2 in deep subsurface rock formations. We describe our implementation, and demonstrate our plugin on porous material images. This paper targets end-users, with relevant information for developers to extend its current capabilities.

  13. CT analysis of the effect of pirfenidone in patients with idiopathic pulmonary fibrosis

    International Nuclear Information System (INIS)

    Iwasawa, Tae; Ogura, Takashi; Sakai, Fumikazu; Kanauchi, Tetsu; Komagata, Takanobu; Baba, Tomohisa; Gotoh, Toshiyuki; Morita, Satoshi; Yazawa, Takuya; Inoue, Tomio

    2014-01-01

    Purpose: Pirfenidone is a new, anti-fibrotic drug used for the treatment of idiopathic pulmonary fibrosis (IPF). The aim of this study was to evaluate the utility of computed tomography (CT) in the imaging assessment of the response to pirfenidone therapy. Materials and methods: Subjects were 78 patients with IPF who underwent CT on two occasions with one-year interval (38 consecutive patients treated with pirfenidone and 40 age-matched control). Changes in the fibrous lesion on sequential CTs were assessed as visual score by two radiologists. We measured the volume and change per year of fibrous pattern (F-pattern) quantitatively using a computer-aided system on sequential CTs. Results: The baseline vital capacity (%pred VC) was 74.0 ± 14.0% in the pirfenidone group and 74.6 ± 16.6% in controls (p = NS). Deterioration of respiratory status was defined as 10% or greater decline in %pred VC value after 12-month treatment. A significantly larger proportion of pirfenidone-treated patients showed stable respiratory status (21 of 38, 65.6%) than the control (15 of 40, 37.5%). The change in fibrous lesion was significantly smaller in the pirfenidone group than the control in both of visual score (p = 0.006) and computer analysis (p < 0.001). The decline in VC correlated significantly with the increase in fibrotic lesion (p < 0.001). Conclusion: CT can be used to assess pirfenidone-induced slowing of progression of pulmonary fibrosis.

  14. CT analysis of the effect of pirfenidone in patients with idiopathic pulmonary fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Iwasawa, Tae, E-mail: tae_i_md@wb3.so-net.ne.jp [Department of Radiology, Kanagawa Cardiovascular and Respiratory Center, Yokohama (Japan); Ogura, Takashi [Department of Respiratory Medicine, Kanagawa Cardiovascular and Respiratory Center, Yokohama (Japan); Sakai, Fumikazu [Department of Diagnostic Radiology, International Medical Center of Saitama Medical University, Saitama (Japan); Kanauchi, Tetsu [Department of Radiology, Saitama Cardiovascular and Respiratory Center, Saitama (Japan); Komagata, Takanobu [Department of Radiology, Kanagawa Cardiovascular and Respiratory Center, Yokohama (Japan); Baba, Tomohisa [Department of Respiratory Medicine, Kanagawa Cardiovascular and Respiratory Center, Yokohama (Japan); Gotoh, Toshiyuki [Graduate School of Environment and Information Sciences, Yokohama National University, Yokohama (Japan); Morita, Satoshi [Department of Biostatistics and Epidemiology, Yokohama City University Medical Center (Japan); Yazawa, Takuya [Department of Pathology, Kyorin University School of Medicine, Tokyo (Japan); Inoue, Tomio [Department of Radiology Yokohama City University, School of Medicine, Yokohama (Japan)

    2014-01-15

    Purpose: Pirfenidone is a new, anti-fibrotic drug used for the treatment of idiopathic pulmonary fibrosis (IPF). The aim of this study was to evaluate the utility of computed tomography (CT) in the imaging assessment of the response to pirfenidone therapy. Materials and methods: Subjects were 78 patients with IPF who underwent CT on two occasions with one-year interval (38 consecutive patients treated with pirfenidone and 40 age-matched control). Changes in the fibrous lesion on sequential CTs were assessed as visual score by two radiologists. We measured the volume and change per year of fibrous pattern (F-pattern) quantitatively using a computer-aided system on sequential CTs. Results: The baseline vital capacity (%pred VC) was 74.0 ± 14.0% in the pirfenidone group and 74.6 ± 16.6% in controls (p = NS). Deterioration of respiratory status was defined as 10% or greater decline in %pred VC value after 12-month treatment. A significantly larger proportion of pirfenidone-treated patients showed stable respiratory status (21 of 38, 65.6%) than the control (15 of 40, 37.5%). The change in fibrous lesion was significantly smaller in the pirfenidone group than the control in both of visual score (p = 0.006) and computer analysis (p < 0.001). The decline in VC correlated significantly with the increase in fibrotic lesion (p < 0.001). Conclusion: CT can be used to assess pirfenidone-induced slowing of progression of pulmonary fibrosis.

  15. Impact of PET/CT system, reconstruction protocol, data analysis method, and repositioning on PET/CT precision: An experimental evaluation using an oncology and brain phantom.

    Science.gov (United States)

    Mansor, Syahir; Pfaehler, Elisabeth; Heijtel, Dennis; Lodge, Martin A; Boellaard, Ronald; Yaqub, Maqsood

    2017-12-01

    In longitudinal oncological and brain PET/CT studies, it is important to understand the repeatability of quantitative PET metrics in order to assess change in tracer uptake. The present studies were performed in order to assess precision as function of PET/CT system, reconstruction protocol, analysis method, scan duration (or image noise), and repositioning in the field of view. Multiple (repeated) scans have been performed using a NEMA image quality (IQ) phantom and a 3D Hoffman brain phantom filled with 18 F solutions on two systems. Studies were performed with and without randomly (PET/CT, especially in the case of smaller spheres (PET metrics depends on the combination of reconstruction protocol, data analysis methods and scan duration (scan statistics). Moreover, precision was also affected by phantom repositioning but its impact depended on the data analysis method in combination with the reconstructed voxel size (tissue fraction effect). This study suggests that for oncological PET studies the use of SUV peak may be preferred over SUV max because SUV peak is less sensitive to patient repositioning/tumor sampling. © 2017 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  16. Morphometric analysis of acetabular dysplasia in cerebral palsy: three-dimensional CT study.

    Science.gov (United States)

    Gose, Shinichi; Sakai, Takashi; Shibata, Toru; Murase, Tsuyoshi; Yoshikawa, Hideki; Sugamoto, Kazuomi

    2009-12-01

    Three-dimensional computed tomography (3D-CT) eliminates the positioning errors and allows the clinician to more accurately assess the radiographic parameters present. To elucidate the 3D geometry of the acetabulum and the extent of hip subluxation/dislocation in patients with cerebral palsy (CP), quantitative morphometric analysis was performed using 3D-CT data. We evaluated 150 hips in 75 patients with bilateral spastic CP. The mean age of the patients was 5.4 years (range: 2.7 to 6.9 y). The fitting plane of the ilium was projected onto the coronal plane and then onto the sagittal plane, and then the angle formed with a horizontal line was defined as CTalpha (the lateral opening angle) and CTbeta (the sagittal inclination angle), respectively. The center of the acetabulum and the femoral head were defined, and the distance between these centers was divided by the femoral head diameter, defined as CT migration percentage (CTMP, %). In 123 (82%) of the 150 hips, the femoral head center was located posteriorly, superiorly, and laterally relative to the acetabular center. Large CTalpha cases tended to show large CTMP. CTalpha and CTMP were significantly larger in the cases with Gross Motor Functional Classification System (GMFCS) level IV/V and spastic quadriplegia, than in the cases with GMFCS level II/III and spastic diplegia. CTbeta showed significant correlation with the acetabular defect on the lateral 3D reconstructed images. Three-dimensional acetabular geometry and migration percentage in CP patients can be analyzed quantitatively using 3D-CT regardless of the abnormal spastic posture. The extent of acetabular dysplasia and subluxation is more severe in patients with GMFCS level IV/V and spastic quadriplesia. Level 4.

  17. Ultrasound and PET-CT Correlation in Shoulder Pathology: A 5-Year Retrospective Analysis.

    Science.gov (United States)

    Burke, Christopher J; Walter, William R; Adler, Ronald S; Babb, James S; Sanger, Joseph; Ponzo, Fabio

    2017-10-01

    To correlate shoulder ultrasound and radiography with F-FDG PET-CT to establish FDG uptake and therefore range of metabolic activity, as defined by SUV analysis, in various symptomatic shoulder pathologies. Retrospective database query was performed for shoulder ultrasound and PET-CT scans between January 2012 and January 2017. Patients who had both studies within 1 year were included. Age- and sex-matched control patients with PET-CT scans only were also included. Retrospective image review determined shoulder pathology, and F-FDG SUVmax was measured using regions of interest placed at the glenohumeral joint, rotator cuff/bursa, and bicipital groove. Glenohumeral and acromioclavicular osteoarthrosis was assessed by radiography using the Kellgren-Lawrence classification system. Thirty-three patients had both imaging studies within 1 year. Ten patients (11 cases) were included, ranging in age from 56 to 90 years (mean, 67.9 years). Control subjects were selected among patients receiving PET-CT within 1 week of symptomatic patients. Glenohumeral osteoarthrosis was mild in 3 (27%), moderate in 2 (18%), and severe in 2 (18%). Six full-thickness rotator cuff tears (55%) were identified. SUVmax means were compared between the pathologic and control groups and were significantly higher in the former: glenohumeral joint (1.96 vs 1.32; P = 0.016), rotator cuff/bursa (2.80 vs 2.0; P = 0.005), and bicipital groove (2.19 vs 1.48; P = 0.007). The highest values were seen in full-thickness rotator cuff tear and severe biceps tenosynovitis. Increased metabolic activity about the shoulder is associated with a spectrum of rotator cuff, glenohumeral joint, and other soft tissue pathology that can be correlated with diagnostic ultrasound findings.

  18. Calculations and analysis of the radiation protection of PET/CT Center

    International Nuclear Information System (INIS)

    Ivanova, S.; Artinyan, A.

    2015-01-01

    Positron Emission Tomography (PET) has been available in number of centers for more than 25 years, but its use was not wide spread until 10 years ago. In Bulgarian PET/CT was installed for the first time in 2009 in Nuclear Medicine Department in University Hospital St. Marina in Varna, Bulgaria. As a physicists the aim for us was to consider and calculate the shielding so that to protect the people and the staff. The purpose of this paper is calculating and analysis of the radiation protection and shielding of Nuclear Medicine Center including PET/CT center situated in University Hospital St. Marina in Varna, Bulgaria. Following the Recommendation of International Commission of Radiation Protection (ICRP) Report 60, Report 73, American Association of Physics in Medicine (AAPM) Task Group 108: PET and PET/CT Shielding Requirements, Medical Physics, DIN 6844-3, Installation of Nuclear Medicine; Radiation protection calculation and the Bulgarian regulations in NM, the new Department was made. The design of the Existing Department was renovated following the requirements for PET/CT Center. The shielding was calculated for imaging room as well as the uptake room, resting room, the PET control room, places above and under the facility, patient WCs and other surrounding laboratories and stuff cabinets. The radiotracer used for the examinations is fluoro-2-desixyglucose (FDG). FDG is labeled with F-18, whose time of flight is only 109min, but it is positron emitting. The energy of annihilation is 511keV. The aim was achieved. The Department was opened. It is working now with about 15 patients every day. The dose rates measured with personal TLD’s for the last 5 years for the stuff are under 3mSv. As the average dose is around 1mSv, and the doses over 1mSv are only for nurses who injected the FDG. (authors)

  19. The prevalence of lumbar spondylolysis in young children: a retrospective analysis using CT.

    Science.gov (United States)

    Lemoine, Thibaut; Fournier, Joseph; Odent, Thierry; Sembély-Taveau, Catherine; Merenda, Pauline; Sirinelli, Dominique; Morel, Baptiste

    2017-10-13

    Although lumbar spondylolysis is encountered in general population with an incidence estimated to be 3-10%, limited information is available for children. The aim of the study is to determine the prevalence of spondylolysis according to associated vertebral bony malformation and spinopelvic parameters in children under eight requiring CT evaluation for unrelated lumbar conditions. Seven hundred and seventeen abdominal and pelvic multi-detector CT scans were obtained in patients under 8 years of age were reviewed. Two board certificated radiologists and two resident radiologists retrospectively evaluated CT scans for lumbar spondylolysis and associated malformations. Pelvic incidence and spondylolisthesis were reported. Our analysis included 717 CT scans in 532 children (259 girls and 273 boys). Twenty-five cases of spondylolysis were diagnosed (16 bilateral and 9 unilateral, 64 and 36%, respectively) in 14 boys (56%) and 11 girls (44%), associating with 12 grade I spondylolisthesis. The mean normal pelvic incidence was 45° (median 44°, SD 7°). The prevalence of spondylolysis was 1% in children under age 3 (n = 3 among 292 patients), 3.7% in children under age 6 (n = 17 among 454 patients) and 4.7% among the 532 patients. Unilateral spondylolysis was significantly associated with a spinal malformation (p = 0.04, Fisher's exact test), with normal pelvic incidence. Half of the patients with bilateral spondylolysis had high pelvic incidence. We observed a prevalence peak of unilateral spondylolysis in the context of a specific malformation in young infants under age 4 with normal pelvic incidence, and, then, a progressive increase in the prevalence of bilateral isolated spondylolysis.

  20. Alveolar bone healing in rats: micro-CT, immunohistochemical and molecular analysis

    Directory of Open Access Journals (Sweden)

    Jaqueline Suemi HASSUMI

    2018-06-01

    Full Text Available Abstract Alveolar bone healing after upper incisor extraction in rats is a classical model of preclinical studies. The underlying morphometric, cellular and molecular mechanism, however, remains imprecise in a unique study. Objectives The aim of this study was therefore to characterize the alveolar bone healing after upper incisor extraction in rats by micro computed tomographic (Micro-CT, immunohistochemical and real-time polymerase chain reaction (RT-PCR analysis. Material and Methods Thirty animals (Rattus norvegicus, Albinus Wistar were divided into three groups after upper incisors extraction at 7, 14, and 28 days. Micro-CT was evaluated based on the morphometric parameters. Subsequently, the histological analyses and immunostaining of osteoprotegerin (OPG, receptor activator of nuclear kappa B ligand (RANKL and tartrate resistant acid phosphate (TRAP was performed. In addition, RT-PCR analyses of OPG, RANKL, the runt-related transcription factor 2 (RUNX2, osteocalcin (OC, osteopontin (OPN, osterix (OST and receptor activator of nuclear kappa B (RANK were performed to determine the expression of these proteins in the alveolar bone healing. Results Micro-CT: The morphometric parameters of bone volume and trabecular thickness progressively increased over time. Consequently, a gradual decrease in trabecular separation, trabecular space and total bone porosity was observed. Immunohistochemical: There were no differences statistically significant between the positive labeling for OPG, RANKL and TRAP in the different periods. RT-PCR: At 28 days, there was a significant increase in OPG expression, while RANKL expression and the RANKL/OPG ratio both decreased over time. Conclusion Micro-CT showed the newly formed bone had favorable morphometric characteristics of quality and quantity. Beyond the RUNX2, OC, OPN, OST, and RANK proteins expressed in the alveolar bone healing, OPG and RANKL activity showed to be essential for activation of basic

  1. Comparison of 18F-FDG PET to CT scan in the detection of recurrent colorectal carcinoma - an ROC analysis

    International Nuclear Information System (INIS)

    Scott, A.M.; Akhurst, T.; Berlangieri, S.U.; Fitt, G.; Schelleman, T.; Jones, R.; Hannah, A.; Tochon-Danguy, H.

    2000-01-01

    Full text: This study examined 43 scans performed in 40 patients from a group of 93 prospectively enrolled in a trial examining the utility of 18 F-FDG PET in patients with potentially resectable recurrent colorectal cancer. All patients had PET and CT scans prior to surgery, where a total of 84 anatomical regions were biopsied, and 364 regions examined by the surgeons. All PET and CT scans were viewed blinded to clinical and imaging data. The scans were interpreted according to a five-point confidence scale to enable an ROC analysis to be performed. An assessment of the impact of PET over CT in patients was also made. Of the 43 cases PET and CT were concordant in 24 (56%). There were 16 cases where PET added additional diagnostic information to the benefit of the patient (37%), and three (7%) where PET alone would have lead to a potentially negative outcome. The majority of cases where PET performed better were in cases with extrahepatic disease. CT was more sensitive in the detection of pulmonary nodules, although the specificity of CT was less than PET. In conclusion, 18 F-FDG PET performed significantly better than CT both in terms of a regional analysis as well as a patient by patient basis. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  2. AFROC analysis of reporting radiographer's performance in CT head interpretation

    International Nuclear Information System (INIS)

    Lockwood, P.; Piper, K.

    2015-01-01

    Aim: A preliminary small scale study to assess the diagnostic performance of a limited group of reporting radiographers and consultant radiologists in clinical practice undertaking computed tomography (CT) head interpretation. Method: A multiple reader multiple case (MRMC) alternative free response receiver operating characteristic (AFROC) methodology was applied. Utilising an image bank of 30 CT head examinations, with a 1:1 ratio of normal to abnormal cases. A reference standard was established by double reporting the original reports using two additional independent consultant radiologists with arbitration of discordance by the researcher. Twelve observers from six southern National Health Service (NHS) trusts were invited to participate. The results were compared for accuracy, agreement, sensitivity, specificity. Data analysis used AFROC and area under the curve (AUC) with standard error. Results: The reporting radiographers results demonstrated a mean sensitivity rate of 88.7% (95% CI 82.3–95.1%), specificity 95.6% (96% CI 90.1–100%) and accuracy of 92.2% (95% CI 89.3–95%). The consultant radiologists mean sensitivity rate was 83.35% (95% CI 80–86.7%), specificity 90% (95% CI 86.7–93.3%) and accuracy of 86.65% (95% CI 83.3–90%). Observer performance between the two groups was compared with AFROC, AUC, and standard error analysis (p = 0.94, SE 0.202). Conclusion: The findings of this research indicate that within a limited study, a small group of reporting radiographers demonstrated high levels of diagnostic accuracy in the interpretation of CT head examinations that was equivalent to a small selection of consultant radiologists. - Highlights: • We assessed reporting radiographers and consultant radiologists in a clinical setting. • This was a small scale retrospective multi-reader multi-case multi-site study. • AFROC used lesion-based decisions rather than case-based decisions. • Within a limited study the observed performance was high in

  3. Maternal MTHFR polymorphism (677 C-T) and risk of Down's syndrome child: meta-analysis.

    Science.gov (United States)

    Kaur, Amandeep; Kaur, Anupam

    2016-09-01

    Methylenetetrahydrofolate reductase (MTHFR) is the most important gene that participates in folate metabolism. Presence of valine instead of alanine at position 677 and elevated levels of homocystein causes DNA hypomethylation which in turn favours nondisjunction. In this study, we conducted a meta-analysis to establish link between maternal single-nucleotide polymorphism (SNP) and birth of Down's syndrome (DS) child. A total of 37 case-control studies were selected for analysis including our own, in which we investigated 110 cases and 111 control mothers. Overall, the result of meta-analysis showed significant risk of DS affected by the presence of maternal SNP (MTHFR 677 C-T OR = 0.816, 95% CI = 0.741-0.900, P <0.0001). Heterogeneity of high magnitude was observed among the studies. The chi-square value suggested a highly significant association between homozygous mutant TT genotype and birth of DS child (χ² = 23.63, P = 0.000). Genetic models suggested that 'T' allele possesses high risk for DS whether present in dominant (OR = 1.23, 95% CI = 1.13-1.34); codominant (OR = 1.17, 95% CI = 1.10-1.25) or recessive (OR = 1.21, 95% CI = 1.05-1.38) form. The analysis from all 37 studies combined together suggested that MTHFR 677 C-T is a major risk factor for DS birth.

  4. Characterization of PET/CT images using texture analysis: the past, the present... any future?

    International Nuclear Information System (INIS)

    Hatt, Mathieu; Visvikis, Dimitris; Tixier, Florent; Le Rest, Catherine Cheze; Pierce, Larry; Kinahan, Paul E.

    2017-01-01

    After seminal papers over the period 2009 - 2011, the use of texture analysis of PET/CT images for quantification of intratumour uptake heterogeneity has received increasing attention in the last 4 years. Results are difficult to compare due to the heterogeneity of studies and lack of standardization. There are also numerous challenges to address. In this review we provide critical insights into the recent development of texture analysis for quantifying the heterogeneity in PET/CT images, identify issues and challenges, and offer recommendations for the use of texture analysis in clinical research. Numerous potentially confounding issues have been identified, related to the complex workflow for the calculation of textural features, and the dependency of features on various factors such as acquisition, image reconstruction, preprocessing, functional volume segmentation, and methods of establishing and quantifying correspondences with genomic and clinical metrics of interest. A lack of understanding of what the features may represent in terms of the underlying pathophysiological processes and the variability of technical implementation practices makes comparing results in the literature challenging, if not impossible. Since progress as a field requires pooling results, there is an urgent need for standardization and recommendations/guidelines to enable the field to move forward. We provide a list of correct formulae for usual features and recommendations regarding implementation. Studies on larger cohorts with robust statistical analysis and machine learning approaches are promising directions to evaluate the potential of this approach. (orig.)

  5. Characterization of PET/CT images using texture analysis: the past, the present... any future?

    Energy Technology Data Exchange (ETDEWEB)

    Hatt, Mathieu; Visvikis, Dimitris [University of Brest IBSAM, INSERM, UMR 1101, LaTIM, Brest (France); Tixier, Florent; Le Rest, Catherine Cheze [University Hospital, Nuclear Medicine, Poitiers (France); University of Poitiers, Medical school, EE DACTIM, Poitiers (France); Pierce, Larry; Kinahan, Paul E. [University of Washington, Imaging Research Laboratory, Seattle, WA (United States)

    2017-01-15

    After seminal papers over the period 2009 - 2011, the use of texture analysis of PET/CT images for quantification of intratumour uptake heterogeneity has received increasing attention in the last 4 years. Results are difficult to compare due to the heterogeneity of studies and lack of standardization. There are also numerous challenges to address. In this review we provide critical insights into the recent development of texture analysis for quantifying the heterogeneity in PET/CT images, identify issues and challenges, and offer recommendations for the use of texture analysis in clinical research. Numerous potentially confounding issues have been identified, related to the complex workflow for the calculation of textural features, and the dependency of features on various factors such as acquisition, image reconstruction, preprocessing, functional volume segmentation, and methods of establishing and quantifying correspondences with genomic and clinical metrics of interest. A lack of understanding of what the features may represent in terms of the underlying pathophysiological processes and the variability of technical implementation practices makes comparing results in the literature challenging, if not impossible. Since progress as a field requires pooling results, there is an urgent need for standardization and recommendations/guidelines to enable the field to move forward. We provide a list of correct formulae for usual features and recommendations regarding implementation. Studies on larger cohorts with robust statistical analysis and machine learning approaches are promising directions to evaluate the potential of this approach. (orig.)

  6. Pre and post PET-CT impact on oesophageal cancer management: a retrospective analysis.

    Science.gov (United States)

    Azmi, NA; Razak, HRA; Vinjamuri, S.

    2017-05-01

    Assessment of the retrospective cancer incidence, prevalence and crude survival rates of oesophageal cancer to allow comparison between pre and post PET-CT introduction are part of 4 phase cost effectiveness research. It will provide baseline data for to assess PET or PET-CT cost effective potential for staging. A total of 849 patient’s data received from NWCIS databases with various stages of oesophageal cancer between 2001 and 2008. The fundamental activities are retrospective analysis of patient data. In most cases where appropriate, results are presented with 95 percent confidence intervals (CI). Variances between patient groups and variables are assessed using chi-square test. In cases where it deems vital, multiple logistic regression are used to modify for potential confounder such as age and sex. All p-values are two-sided and any value lower than 0.05 were considered to suggest a statistically significant result. Retrospective analysis were categorised into two categories, patients from 2001-2003 considered as pre PET and post PET for 2004-2008. This categorisation allows better comparison of patients’ survival trend to be made between both groups. Rates are presented in percentages and being grouped by tumour characteristics and other variables associated with demographic profile, diagnosis, staging and treatment. Results allowed comparison of oesophageal cancer trends between the pre and post PET-CT introduction such as changes in incidence rate or changes in survival. These data were used to normalise the decision tree model so that cost-effectiveness analysis can be performed across the whole population.

  7. Pre and post PET-CT impact on oesophageal cancer management: a retrospective analysis

    International Nuclear Information System (INIS)

    Azmi, NA; Razak, HRA; Vinjamuri, S

    2017-01-01

    Assessment of the retrospective cancer incidence, prevalence and crude survival rates of oesophageal cancer to allow comparison between pre and post PET-CT introduction are part of 4 phase cost effectiveness research. It will provide baseline data for to assess PET or PET-CT cost effective potential for staging. A total of 849 patient’s data received from NWCIS databases with various stages of oesophageal cancer between 2001 and 2008. The fundamental activities are retrospective analysis of patient data. In most cases where appropriate, results are presented with 95 percent confidence intervals (CI). Variances between patient groups and variables are assessed using chi-square test. In cases where it deems vital, multiple logistic regression are used to modify for potential confounder such as age and sex. All p-values are two-sided and any value lower than 0.05 were considered to suggest a statistically significant result. Retrospective analysis were categorised into two categories, patients from 2001-2003 considered as pre PET and post PET for 2004-2008. This categorisation allows better comparison of patients’ survival trend to be made between both groups. Rates are presented in percentages and being grouped by tumour characteristics and other variables associated with demographic profile, diagnosis, staging and treatment. Results allowed comparison of oesophageal cancer trends between the pre and post PET-CT introduction such as changes in incidence rate or changes in survival. These data were used to normalise the decision tree model so that cost-effectiveness analysis can be performed across the whole population. (paper)

  8. CT interpretation of craniofacial anomalies: a comparative analysis by undergraduate dental students; Interpretacao de anomalias craniofaciais em TC. Analise comparativa por alunos de graduacao em Odontologia

    Energy Technology Data Exchange (ETDEWEB)

    Gaia, Bruno Felipe; Perella, Andreia; Cara, Ana Claudia Ballet de [Sao Paulo Univ., SP (Brazil). Faculdade de Odontologia; Antunes, Jose Leopoldo Ferreira [Sao Paulo Univ., SP (Brazil). Faculdade de Odontologia. Dept. de Odontologia Social; Cavalcanti, Marcelo Gusmao Paraiso [Sao Paulo Univ., SP (Brazil). Faculdade de Odontologia. Dept. de Radiologia

    2005-01-15

    The aim of this study was to evaluate the accuracy and reproducibility of computed tomography (CT) image interpretation made in axial slices (2D-CT) and 3D reconstructed images (3D-CT) of patients with craniofacial anomalies. The analyses were made by undergraduate dental students, and compared with the diagnoses considered upon surgical intervention. Computed tomography of 43 patients were analyzed independently by three calibrated examiners (undergraduate students) with, respectively, one, two, and three semesters of experience in craniofacial CT training and interpretation. The analysis of 2D-CT and 3D-CT images were performed at distinct times using an independent workstation associated with a specific computer graphics software for volumetric images. The analysis of inter-examiner agreement and of the agreement between observers and the gold standard was performed using the Kappa test. The accuracy evaluation presented a progressively higher value for examiners with progressively broader experience in 2D-CT and 3D-CT image interpretation. 3D-CT analyses allowed a higher inter-examiner agreement (1 - 0.896) than 2D-CT analyses (1 - 0.614). 3D-CT was considered more precise and accurate than 2D-CT for all students' evaluations. The reproducibility and accuracy varied according to the experience in CT interpretation, and the most experienced student achieved results closer to the gold standard. (author)

  9. CT colonography for surveillance of patients with colorectal cancer: Systematic review and meta-analysis of diagnostic efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Porte, Francois; Burling, David [St. Mark' s Hospital, Department of Radiology, Harrow (United Kingdom); Uppara, Mallikarjuna; Malietzis, George; Faiz, Omar [Trials and Outcome Centre (SETOC) St Mark' s Hospital, Surgical Epidemiology, Harrow (United Kingdom); Halligan, Steve [University College London, Department of Radiology, London (United Kingdom); Athanasiou, Thanos [Imperial College London, Department of Surgery and Cancer, London (United Kingdom)

    2017-01-15

    To review primary research evidence investigating performance of CT colonography for colorectal cancer surveillance. The financial impact of using CT colonography for surveillance was also estimated. We identified primary studies of CT colonography for surveillance of colorectal cancer patients. A summary ROC curve was constructed. Inter-study heterogeneity was explored using the I2 value. Financial impact was estimated for a theoretical cohort of patients, based on Cancer Research UK statistics. Seven studies provided data on 880 patients. Five of seven studies (765 patients) were included for qualitative analysis. Sensitivity of CT colonography for detection of anastomotic recurrence was 95 % (95 % CI 62 - 100), specificity 100 % (95 % CI 75 - 100) and sensitivity for metachronous cancers was 100 %. No statistical heterogeneity was detected (I2 = 0 %). We estimated that CT colonography as a 'single test' alternative to colonoscopy and standard CT for surveillance would potentially save EUR20,785,232 (pound 14,803,404) for an annual cohort of UK patients. CT colonography compares favourably to colonoscopy for detection of anastomotic recurrence and metachronous colorectal cancer, and appears financially beneficial. These findings should be considered alongside limitations of small patient numbers and high clinical heterogeneity between studies. (orig.)

  10. Quantitative CT analysis for the preoperative prediction of pathologic grade in pancreatic neuroendocrine tumors

    Science.gov (United States)

    Chakraborty, Jayasree; Pulvirenti, Alessandra; Yamashita, Rikiya; Midya, Abhishek; Gönen, Mithat; Klimstra, David S.; Reidy, Diane L.; Allen, Peter J.; Do, Richard K. G.; Simpson, Amber L.

    2018-02-01

    Pancreatic neuroendocrine tumors (PanNETs) account for approximately 5% of all pancreatic tumors, affecting one individual per million each year.1 PanNETs are difficult to treat due to biological variability from benign to highly malignant, indolent to very aggressive. The World Health Organization classifies PanNETs into three categories based on cell proliferative rate, usually detected using the Ki67 index and cell morphology: low-grade (G1), intermediate-grade (G2) and high-grade (G3) tumors. Knowledge of grade prior to treatment would select patients for optimal therapy: G1/G2 tumors respond well to somatostatin analogs and targeted or cytotoxic drugs whereas G3 tumors would be targeted with platinum or alkylating agents.2, 3 Grade assessment is based on the pathologic examination of the surgical specimen, biopsy or ne-needle aspiration; however, heterogeneity in the proliferative index can lead to sampling errors.4 Based on studies relating qualitatively assessed shape and enhancement characteristics on CT imaging to tumor grade in PanNET,5 we propose objective classification of PanNET grade with quantitative analysis of CT images. Fifty-five patients were included in our retrospective analysis. A pathologist graded the tumors. Texture and shape-based features were extracted from CT. Random forest and naive Bayes classifiers were compared for the classification of G1/G2 and G3 PanNETs. The best area under the receiver operating characteristic curve (AUC) of 0:74 and accuracy of 71:64% was achieved with texture features. The shape-based features achieved an AUC of 0:70 and accuracy of 78:73%.

  11. The factor analysis of the incidence of pneumothorax after CT-guided transthoracic needle aspiration biopsy

    International Nuclear Information System (INIS)

    Zhong Tao; Yu Hongguang; Wang Yong; Yang Sifu; Wang Xiaoxuan

    2007-01-01

    Objective: To analyze the impact of multiple factors on the incidence of pneumothorax associated with CT-guided transthoracic needle aspiration biopsy. Methods: The sign of pneumothorax after 162 cases (lesion diameter from 1 cm to 6 cm) CT-guided transthoracic needle aspiration biopsy was observed and its relationship with multivariate factors were analyzed by multivariate logistic regression model. Results: Thirty-two cases presented pneumothorax accounting for 19. 8%. Single variate analysis showed that the sign of pneumothorax related to intercurrent COPD, distance from lesion and chest wall, needle dwelling time and lesion diameter. 67 patients of intercurrent COPD with postoperative pneumothorax occurred in 22 cases (32.8%); With respect to those having lesions close to the chest wall (48 cases), and the cases with the distance between the chest wall and lesions less than 2 cm (55 cases) and greater than 2 cm (59 cases), the postoperative pneumothorax occurred in 0, 14 (25.5%), 18 (30.5%) cases respectively; For those patients with needle in the chest residence time of less than 10 minutes (82 cases), 10-20 minutes (51 cases), more than 20 minutes (28 cases) after the occurrence of pneumothorax were 8 (9.6%), 10(19.6%), 14 (50%) cases respectively; In contrast, those with lesion diameter less than 2 cm (65 cases), 2-4 cm(52 cases), more than 4cm(45 cases) were 19 (29.2%), 8 (15.4%) and 5 (11.1% ) respectively. The multivariate logistic regression analysis showed that the prior three factor's were risk factors of pneumothorax (OR=4.652, 4.030, 2.855 respectively). Conclusions: To avoid the pneumothorax, caution must be taken with respect to CT-guided transthoracic needle aspiration biopsy, patients with intercurrent COPD, long distance between lesion and chest wall, and smaller lesion diameter. For operation the needle dwell time within thorax should be minimized. (authors)

  12. Variation compensation and analysis on diaphragm curvature analysis for emphysema quantification on whole lung CT scans

    Science.gov (United States)

    Keller, Brad M.; Reeves, Anthony P.; Barr, R. Graham; Yankelevitz, David F.; Henschke, Claudia I.

    2010-03-01

    CT scans allow for the quantitative evaluation of the anatomical bases of emphysema. Recently, a non-density based geometric measurement of lung diagphragm curvature has been proposed as a method for the quantification of emphysema from CT. This work analyzes variability of diaphragm curvature and evaluates the effectiveness of a compensation methodology for the reduction of this variability as compared to emphysema index. Using a dataset of 43 scan-pairs with less than a 100 day time-interval between scans, we find that the diaphragm curvature had a trend towards lower overall variability over emphysema index (95% CI:-9.7 to + 14.7 vs. -15.8 to +12.0), and that the variation of both measures was reduced after compensation. We conclude that the variation of the new measure can be considered comparable to the established measure and the compensation can reduce the apparent variation of quantitative measures successfully.

  13. Contrast-enhanced CT in determining resectability in patients with pancreatic carcinoma: a meta-analysis of the positive predictive values of CT

    Energy Technology Data Exchange (ETDEWEB)

    Somers, Inne; Bipat, Shandra [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands)

    2017-08-15

    To obtain a summary positive predictive value (sPPV) of contrast-enhanced CT in determining resectability. The MEDLINE and EMBASE databases from JAN2005 to DEC2015 were searched and checked for inclusion criteria. Data on study design, patient characteristics, imaging techniques, image evaluation, reference standard, time interval between CT and reference standard, and data on resectability/unresectablity were extracted by two reviewers. We used a fixed-effects or random-effects approach to obtain sPPV for resectability. Several subgroups were defined: 1) bolus-triggering versus fixed-timing; 2) pancreatic and portal phases versus portal phase alone; 3) all criteria (liver metastases/lymphnode involvement/local advanced/vascular invasion) versus only vascular invasion as criteria for unresectability. Twenty-nine articles were included (2171 patients). Most studies were performed in multicentre settings, initiated by the department of radiology and retrospectively performed. The I{sup 2}-value was 68%, indicating heterogeneity of data. The sPPV was 81% (95%CI: 75-86%). False positives were mostly liver, peritoneal, or lymphnode metastases. Bolus-triggering had a slightly higher sPPV compared to fixed-timing, 87% (95%CI: 81-91%) versus 78% (95%CI: 66-86%) (p = 0.077). No differences were observed in other subgroups. This meta-analysis showed a sPPV of 81% for predicting resectability by CT, meaning that 19% of patients falsely undergo surgical exploration. (orig.)

  14. Three-dimensional image analysis of the skull using variable CT scanning protocols-effect of slice thickness on measurement in the three-dimensional CT images

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ho Gul; Kim, Kee Deog; Park, Hyok; Kim, Dong Ook; Jeong, Hai Jo; Kim, Hee Joung; Yoo, Sun Kook; Kim, Yong Oock; Park, Chang Seo [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2004-07-15

    To evaluate the quantitative accuracy of three-dimensional (3D) images by mean of comparing distance measurements on the 3D images with direct measurements of dry human skull according to slice thickness and scanning modes. An observer directly measured the distance of 21 line items between 12 orthodontic landmarks on the skull surface using a digital vernier caliper and each was repeated five times. The dry human skull was scanned with a Helical CT with various slice thickness (3, 5, 7 mm) and acquisition modes (Conventional and Helical). The same observer measured corresponding distance of the same items on reconstructed 3D images with the internal program of V-works 4.0 (Cybermed Inc., Seoul, Korea). The quantitative accuracy of distance measurements were statistically evaluated with Wilcoxons' two-sample test. 11 line items in Conventional 3 mm, 8 in Helical 3 mm, 11 in Conventional 5 mm, 10 in Helical 5 mm, 5 in Conventional 7 mm and 9 in Helical 7 mm showed no statistically significant difference. Average difference between direct measurements and measurements on 3D CT images was within 2 mm in 19 line items of Conventional 3 mm. 20 of Helical 3 mm, 15 of Conventional 5 mm, 18 of Helical 5 mm, 11 of Conventional 7 mm and 16 of Helical 7 mm. Considering image quality and patient's exposure time, scanning protocol of Helical 5 mm is recommended for 3D image analysis of the skull in CT.

  15. 18FDG-PET in 733 consecutive patients with or without side-by-side CT evaluation. Analysis of 921 lesions

    International Nuclear Information System (INIS)

    Buell, U.; Wieres, F.J.; Schneider, W.; Reinartz, P.

    2004-01-01

    Side-by-side analysis of CT and conventional 18 FDG-PET in oncological imaging is well established. Aim of this study was to find out which patients or diagnostic groups may benefit the most from the newly introduced integrated PET/CT scanners. Patients, methods: 407 consecutively admitted oncological patients with accompanying CT (groups A-D) and 326 patients without CT (groups E-G) were examined by conventional ring PET. Two nuclear medicine physicians and two radiologists assessed each patient's PET and CT scans for pathological lesions with regard to localisation and infiltration of adjacent anatomical structures. Patients without pathological PET findings were assigned to groups A (with CT) or E (without CT). If the localisation and/or extent of a pathological PET focus could only be assessed by taking into account the CT scan, the patient was assigned to group C (with CT) or G (without CT). If PET alone was sufficient for both questions the patient was assigned to groups B (with CT) or F (without CT). If neither method allowed for a precise lesion characterisation, the patient was assigned to group D. Results: 38.6% (A, E) of all patients were PET-negative. PET alone sufficed in 20.6% (B, F). Side-by-side reading of PET and CT was needed for 43.5% (C) of patients referred to PET with a current CT. Side-by-side reading of CT and PET did not suffice for 7.3% (D) of patients in that cohort. A total of 28.2% (G) of the cases without CT would have profited from it. The most frequent oncological diagnoses in group D (PET and conventional CT not sufficient) were bronchial carcinoma with abdominal lesions, while in group G (without CT but CT required) head/neck cancer with thoracic lesions was predominant. Conclusions: Side-by-side reading of PET and already existing conventional CT failed to yield conclusive data with regard to lesion characterisation in only 7.4% of patients so that PET/CT might have been helpful in these cases. 28.2% of the patients without

  16. Diagnosis of mediastinal neoplasms using mediastinoscopy and CT-guided needle biopsy supported by gene analysis

    International Nuclear Information System (INIS)

    Chiba, Wataru; Sawai, Satoru; Ishida, Hisao; Hanawa, Takeshi; Matsubara, Yoshito; Ikeda, Sadao; Kinoshita, Moritoshi; Ikei, Nobuhiro.

    1993-01-01

    Of 140 cases of mediastinal neoplasms in our hospital, histological diagnosis was confirmed in 129 cases. We examined the methods of preoperative biopsy with those 129 cases. Biopsy had been performed in 25 cases. Mediastinoscopy was performed in seven cases, needle biopsy in eight cases, lymph node biopsy in eight cases, esophageal biopsy using a gastrofiberscope in one case, transbronchial biopsy using a bronchoscope in one case. The true positive rates of those methods were 100% for both mediastinoscopy and lymph node biopsy, and 75% for needle biopsy. Preoperative misdiagnosis occurred in two cases of needle biopsy. The postoperative histological diagnosis was malignant lymphoma in both cases. We performed gene analysis of the immunoglobulin heavy chain gene, light chain κ and λ genes, and the T-cell receptor β gene by use of biopsied specimens, and we found rearrangement bands of these genes in the cases of malignant lymphoma. Therefore, we summarize that gene analysis is a reliable method if malignant lymphoma is suspected. If a needle biopsy is performed under CT guidance, the needle is sure to puncture the tumor. We concluded, therefore, that if a tumor is located in the anterior mediastinum, CT-guided needle biopsy should be performed first of all. Mediastinoscopy is a useful method if the tumor is located in the mid-mediastinum. (author)

  17. Sexual difference of human hyoid bones. Quantitative analysis of CT three-dimensional image

    International Nuclear Information System (INIS)

    Terashima, Yoshiharu; Izumi, Masahiro; Hanamura, Hajime; Takada, Yasushi

    2007-01-01

    We investigated sexual differences in hyoid bones of 50 dissected Japanese cadavers: 26 males (aged 52 to 101, averaged 81.9 years) and 24 females (aged 61 to 94, averaged 83.6 years). All extracted hyoid bones were scanned by multi-slice CT. Length of body, distance between bilateral greater horns, length of greater horns, distance between bilateral lesser horns, and length of lesser horns were measured on CT three-dimensional image, and were analyzed by univariate and multivariate statistics. t-tests showed significant sexual differences in all the dimensions; being about 20% longer in males than in females. In principal component analysis using five hyoid dimensions, factor 1, expressing the overall size of the bone, fairly separated each sex, but factors 2 and 3, expressing the shape, did not. Discriminant analysis by a stepwise model, using all the eight dimensions, classified sex rightly (88.6% of the bone) by a function of two dimensions: length of body and distance between bilateral tips of lesser horns. In conclusion, a sexual difference of the hyoid bone was evident in size rather than in shape. (author)

  18. Content analysis of physical examination templates in electronic health records using SNOMED CT.

    Science.gov (United States)

    Gøeg, Kirstine Rosenbeck; Chen, Rong; Højen, Anne Randorff; Elberg, Pia

    2014-10-01

    Most electronic health record (EHR) systems are built on proprietary information models and terminology, which makes achieving semantic interoperability a challenge. Solving interoperability problems requires well-defined standards. In contrast, the need to support clinical work practice requires a local customization of EHR systems. Consequently, contrasting goals may be evident in EHR template design because customization means that local EHR organizations can define their own templates, whereas standardization implies consensus at some level. To explore the complexity of balancing these two goals, this study analyzes the differences and similarities between templates in use today. A similarity analysis was developed on the basis of SNOMED CT. The analysis was performed on four physical examination templates from Denmark and Sweden. The semantic relationships in SNOMED CT were used to quantify similarities and differences. Moreover, the analysis used these identified similarities to investigate the common content of a physical examination template. The analysis showed that there were both similarities and differences in physical examination templates, and the size of the templates varied from 18 to 49 fields. In the SNOMED CT analysis, exact matches and terminology similarities were represented in all template pairs. The number of exact matches ranged from 7 to 24. Moreover, the number of unrelated fields differed a lot from 1/18 to 22/35. Cross-country comparisons tended to have more unrelated content than within-country comparisons. On the basis of identified similarities, it was possible to define the common content of a physical examination. Nevertheless, a complete view on the physical examination required the inclusion of both exact matches and terminology similarities. This study revealed that a core set of items representing the physical examination templates can be generated when the analysis takes into account not only exact matches but also terminology

  19. Grading of Crohn's disease activity using CT, MRI, US and scintigraphy: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Puylaert, C.A.J.; Tielbeek, J.A.W.; Bipat, S.; Stoker, J. [University of Amsterdam, Academic Medical Center, Department of Radiology, Amsterdam (Netherlands)

    2015-11-15

    To assess the grading of Crohn's disease activity using CT, MRI, US and scintigraphy. MEDLINE, EMBASE and Cochrane databases were searched (January 1983-March 2014) for studies evaluating CT, MRI, US and scintigraphy in grading Crohn's disease activity compared to endoscopy, biopsies or intraoperative findings. Two independent reviewers assessed the data. Three-by-three tables (none, mild, frank disease) were constructed for all studies, and estimates of accurate, over- and under-grading were calculated/summarized by fixed or random effects models. Our search yielded 9356 articles, 19 of which were included. Per-patient data showed accurate grading values for CT, MRI, US and scintigraphy of 86 % (95 % CI: 75-93 %), 84 % (95 % CI: 67-93 %), 44 % (95 % CI: 28-61 %) and 40 % (95 % CI: 16-70 %), respectively. In the per-patient analysis, CT and MRI showed similar accurate grading estimates (P = 0.8). Per-segment data showed accurate grading values for CT and scintigraphy of 87 % (95 % CI: 77-93 %) and 86 % (95 % CI: 80-91 %), respectively. MRI and US showed grading accuracies of 67-82 % and 56-75 %, respectively. CT and MRI showed comparable high accurate grading estimates in the per-patient analysis. Results for US and scintigraphy were inconsistent, and limited data were available. (orig.)

  20. Lesion detection performance: comparative analysis of low-dose CT data of the chest on two hybrid imaging systems.

    Science.gov (United States)

    Jessop, Maryam; Thompson, John D; Coward, Joanne; Sanderud, Audun; Jorge, José; de Groot, Martijn; Lança, Luís; Hogg, Peter

    2015-03-01

    Incidental findings on low-dose CT images obtained during hybrid imaging are an increasing phenomenon as CT technology advances. Understanding the diagnostic value of incidental findings along with the technical limitations is important when reporting image results and recommending follow-up, which may result in an additional radiation dose from further diagnostic imaging and an increase in patient anxiety. This study assessed lesions incidentally detected on CT images acquired for attenuation correction on two SPECT/CT systems. An anthropomorphic chest phantom containing simulated lesions of varying size and density was imaged on an Infinia Hawkeye 4 and a Symbia T6 using the low-dose CT settings applied for attenuation correction acquisitions in myocardial perfusion imaging. Twenty-two interpreters assessed 46 images from each SPECT/CT system (15 normal images and 31 abnormal images; 41 lesions). Data were evaluated using a jackknife alternative free-response receiver-operating-characteristic analysis (JAFROC). JAFROC analysis showed a significant difference (P detection, with the figures of merit being 0.599 (95% confidence interval, 0.568, 0.631) and 0.810 (95% confidence interval, 0.781, 0.839) for the Infinia Hawkeye 4 and Symbia T6, respectively. Lesion detection on the Infinia Hawkeye 4 was generally limited to larger, higher-density lesions. The Symbia T6 allowed improved detection rates for midsized lesions and some lower-density lesions. However, interpreters struggled to detect small (5 mm) lesions on both image sets, irrespective of density. Lesion detection is more reliable on low-dose CT images from the Symbia T6 than from the Infinia Hawkeye 4. This phantom-based study gives an indication of potential lesion detection in the clinical context as shown by two commonly used SPECT/CT systems, which may assist the clinician in determining whether further diagnostic imaging is justified. © 2015 by the Society of Nuclear Medicine and Molecular Imaging

  1. Cost-effectiveness analysis of FDG PET-CT in the management of pulmonary metastases from malignant melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Krug, Bruno; Pirson, Anne-Sophie; Borght Thierry Vander (Nuclear Medicine Division, Mont-Godinne Univ. Hospital, Yvoir (Belgium)), E-mail: bruno.krug@uclouvain.be; Crott, Ralph (Public Health, Saint-Luc Univ. Hospital, Brussels (Belgium)); Roch, Isabelle (Public Health School, Univ. Catholique de Louvain, Brussels (Belgium)); Lonneux, Max (Nuclear Medicine Division, Saint-Luc Univ. Hospital, Brussels (Belgium)); Beguin, Claire (Medical Information and Statistics, Saint-Luc Univ. Hospital, Brussels (Belgium)); Baurain, Jean-Francois (Dept. of Oncology, Saint-Luc Univ. Hospital, Brussels (Belgium))

    2010-02-15

    Objectives. Most guidelines consider FDG PET-CT to detect occult extra-pulmonary disease prior to lung metastasectomy. A cost-effectiveness analysis, using a Markov model over a 10 year period, was performed to compare two different surveillance programs, either PET-CT or whole-body CT, in patients with suspected pulmonary metastasised melanoma. Methods. Data from published studies provided probabilities for the model. Complication and care costs were obtained from standardised administrative databases from 19 hospitals identified by DRG codes (reported in 2009 Euros). For the cost calculation of PET-CT we performed a microcosting analysis. All costs and benefits were yearly discounted at respectively 3% and 1.5%. Outcomes included life-months gained (LMG) and the number of futile surgeries avoided. Cost-effectiveness ratios were in Euros per LMG. Univariate and probabilistic sensitivity analyses addressed uncertainty in all model parameters. Results. The PET-CT strategy provided 86.29 LMG (95% CI: 81.50-90.88 LMG) at a discounted cost of Euro 3 974 (95% CI: Euro 1 339-12 303), while the conventional strategy provided 86.08 LMG (95% CI: 81.37-90.68 LMG) at a discounted cost of Euro 5 022 (95% CI: Euro 1 378-16 018). This PET-CT strategy resulted in a net saving of Euro 1 048 with a gain of 0.2 LMG. Based on PET-CT findings, 20% of futile surgeries could be avoided. Conclusion. Integrating PET-CT in the management of patients with high risk MM appears to be less costly and more accurate by avoiding futile thoracotomies in one of five patients as well as by providing a small survival benefit at 10 years

  2. Differentiating pheochromocytoma from lipid-poor adrenocortical adenoma by CT texture analysis: feasibility study.

    Science.gov (United States)

    Zhang, Gu-Mu-Yang; Shi, Bing; Sun, Hao; Jin, Zheng-Yu; Xue, Hua-Dan

    2017-09-01

    To investigate the feasibility of using CT texture analysis (CTTA) to differentiate pheochromocytoma from lipid-poor adrenocortical adenoma (lp-ACA). Ninety-eight pheochromocytomas and 66 lp-ACAs were included in this retrospective study. CTTA was performed on unenhanced and enhanced images. Receiver operating characteristic (ROC) analysis was performed, and the area under the ROC curve (AUC) was calculated for texture parameters that were significantly different for the objective. Diagnostic accuracies were evaluated using the cutoff values of texture parameters with the highest AUCs. Compared to lp-ACAs, pheochromocytomas had significantly higher mean gray-level intensity (Mean), entropy, and mean of positive pixels (MPP), but lower skewness and kurtosis on unenhanced images (P feasible to use CTTA to differentiate pheochromocytoma from lp-ACA.

  3. Local curvature analysis for classifying breast tumors: Preliminary analysis in dedicated breast CT

    International Nuclear Information System (INIS)

    Lee, Juhun; Nishikawa, Robert M.; Reiser, Ingrid; Boone, John M.; Lindfors, Karen K.

    2015-01-01

    Purpose: The purpose of this study is to measure the effectiveness of local curvature measures as novel image features for classifying breast tumors. Methods: A total of 119 breast lesions from 104 noncontrast dedicated breast computed tomography images of women were used in this study. Volumetric segmentation was done using a seed-based segmentation algorithm and then a triangulated surface was extracted from the resulting segmentation. Total, mean, and Gaussian curvatures were then computed. Normalized curvatures were used as classification features. In addition, traditional image features were also extracted and a forward feature selection scheme was used to select the optimal feature set. Logistic regression was used as a classifier and leave-one-out cross-validation was utilized to evaluate the classification performances of the features. The area under the receiver operating characteristic curve (AUC, area under curve) was used as a figure of merit. Results: Among curvature measures, the normalized total curvature (C_T) showed the best classification performance (AUC of 0.74), while the others showed no classification power individually. Five traditional image features (two shape, two margin, and one texture descriptors) were selected via the feature selection scheme and its resulting classifier achieved an AUC of 0.83. Among those five features, the radial gradient index (RGI), which is a margin descriptor, showed the best classification performance (AUC of 0.73). A classifier combining RGI and C_T yielded an AUC of 0.81, which showed similar performance (i.e., no statistically significant difference) to the classifier with the above five traditional image features. Additional comparisons in AUC values between classifiers using different combinations of traditional image features and C_T were conducted. The results showed that C_T was able to replace the other four image features for the classification task. Conclusions: The normalized curvature measure

  4. Automated MicroSPECT/MicroCT Image Analysis of the Mouse Thyroid Gland.

    Science.gov (United States)

    Cheng, Peng; Hollingsworth, Brynn; Scarberry, Daniel; Shen, Daniel H; Powell, Kimerly; Smart, Sean C; Beech, John; Sheng, Xiaochao; Kirschner, Lawrence S; Menq, Chia-Hsiang; Jhiang, Sissy M

    2017-11-01

    The ability of thyroid follicular cells to take up iodine enables the use of radioactive iodine (RAI) for imaging and targeted killing of RAI-avid thyroid cancer following thyroidectomy. To facilitate identifying novel strategies to improve 131 I therapeutic efficacy for patients with RAI refractory disease, it is desired to optimize image acquisition and analysis for preclinical mouse models of thyroid cancer. A customized mouse cradle was designed and used for microSPECT/CT image acquisition at 1 hour (t1) and 24 hours (t24) post injection of 123 I, which mainly reflect RAI influx/efflux equilibrium and RAI retention in the thyroid, respectively. FVB/N mice with normal thyroid glands and TgBRAF V600E mice with thyroid tumors were imaged. In-house CTViewer software was developed to streamline image analysis with new capabilities, along with display of 3D voxel-based 123 I gamma photon intensity in MATLAB. The customized mouse cradle facilitates consistent tissue configuration among image acquisitions such that rigid body registration can be applied to align serial images of the same mouse via the in-house CTViewer software. CTViewer is designed specifically to streamline SPECT/CT image analysis with functions tailored to quantify thyroid radioiodine uptake. Automatic segmentation of thyroid volumes of interest (VOI) from adjacent salivary glands in t1 images is enabled by superimposing the thyroid VOI from the t24 image onto the corresponding aligned t1 image. The extent of heterogeneity in 123 I accumulation within thyroid VOIs can be visualized by 3D display of voxel-based 123 I gamma photon intensity. MicroSPECT/CT image acquisition and analysis for thyroidal RAI uptake is greatly improved by the cradle and the CTViewer software, respectively. Furthermore, the approach of superimposing thyroid VOIs from t24 images to select thyroid VOIs on corresponding aligned t1 images can be applied to studies in which the target tissue has differential radiotracer retention

  5. Correlation analysis between pulmonary function test parameters and CT image parameters of emphysema

    Science.gov (United States)

    Liu, Cheng-Pei; Li, Chia-Chen; Yu, Chong-Jen; Chang, Yeun-Chung; Wang, Cheng-Yi; Yu, Wen-Kuang; Chen, Chung-Ming

    2016-03-01

    Conventionally, diagnosis and severity classification of Chronic Obstructive Pulmonary Disease (COPD) are usually based on the pulmonary function tests (PFTs). To reduce the need of PFT for the diagnosis of COPD, this paper proposes a correlation model between the lung CT images and the crucial index of the PFT, FEV1/FVC, a severity index of COPD distinguishing a normal subject from a COPD patient. A new lung CT image index, Mirage Index (MI), has been developed to describe the severity of COPD primarily with emphysema disease. Unlike conventional Pixel Index (PI) which takes into account all voxels with HU values less than -950, the proposed approach modeled these voxels by different sizes of bullae balls and defines MI as a weighted sum of the percentages of the bullae balls of different size classes and locations in a lung. For evaluation of the efficacy of the proposed model, 45 emphysema subjects of different severity were involved in this study. In comparison with the conventional index, PI, the correlation between MI and FEV1/FVC is -0.75+/-0.08, which substantially outperforms the correlation between PI and FEV1/FVC, i.e., -0.63+/-0.11. Moreover, we have shown that the emphysematous lesion areas constituted by small bullae balls are basically irrelevant to FEV1/FVC. The statistical analysis and special case study results show that MI can offer better assessment in different analyses.

  6. A Look from the Inside: MicroCT Analysis of Burned Bones

    Directory of Open Access Journals (Sweden)

    Francesco Boschin

    2015-12-01

    Full Text Available MicroCT imaging is increasingly used in paleoanthropological and zooarchaeological research to analyse the internal microstructure of bone, replacing comparatively invasive and destructive methods. Consequently the analytical potential of this relatively new 3D imaging technology can be enhanced by developing discipline specific protocols for archaeological analysis. Here we examine how the microstructure of mammal bone changes after burning and explore if X-ray computed microtomography (microCT can be used to obtain reliable information from burned specimens. We subjected domestic pig, roe deer, and red fox bones to burning at different temperatures and for different periods using an oven and an open fire. We observed significant changes in the three-dimensional microstructure of trabecular bone, suggesting that biomechanical studies or other analyses (for instance, determination of age-at-death can be compromised by burning. In addition, bone subjected to very high temperatures (600°C or more became cracked, posing challenges for quantifying characteristics of bone microstructure. Specimens burned at 600°C or greater temperatures, exhibit a characteristic criss-cross cracking pattern concentrated in the cortical region of the epiphyses. This feature, which can be readily observed on the surface of whole bone, could help the identification of heavily burned specimens that are small fragments, where color and surface texture are altered by diagenesis or weathering.

  7. In vivo micro-CT analysis of bone remodeling in a rat calvarial defect model

    Energy Technology Data Exchange (ETDEWEB)

    Umoh, Joseph U; Holdsworth, David W [Pre-Clinical Imaging Research Centre, Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, PO Box 5015, 100 Perth Drive, London, ON N6A 5K8 (Canada); Sampaio, Arthur V; Underhill, T Michael [Laboratory of Molecular Skeletogenesis, Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC (Canada); Welch, Ian [Animal Care and Veterinary Services, University of Western Ontario, London, ON (Canada); Pitelka, Vasek; Goldberg, Harvey A [CIHR Group in Skeletal Development and Remodelling, University of Western Ontario, London, ON (Canada)], E-mail: jumoh@imaging.robarts.ca, E-mail: asampaio@interchange.ubc.ca, E-mail: tunderhi@interchange.ubc.ca, E-mail: iwelch@uwo.ca, E-mail: vasek.pitelka@schulich.uwo.ca, E-mail: hagoldbe@uwo.ca, E-mail: david.holdsworth@imaging.robarts.ca

    2009-04-07

    The rodent calvarial defect model is commonly used to investigate bone regeneration and wound healing. This study presents a micro-computed tomography (micro-CT) methodology for measuring the bone mineral content (BMC) in a rat calvarial defect and validates it by estimating its precision error. Two defect models were implemented. A single 6 mm diameter defect was created in 20 rats, which were imaged in vivo for longitudinal experiments. Three 5 mm diameter defects were created in three additional rats, which were repeatedly imaged ex vivo to determine precision. Four control rats and four rats treated with bone morphogenetic protein were imaged at 3, 6, 9 and 12 weeks post-surgery. Scan parameters were 80 kVp, 0.45 mA and 180 mAs. Images were reconstructed with an isotropic resolution of 45 {mu}m. At 6 weeks, the BMC in control animals (4.37 {+-} 0.66 mg) was significantly lower (p < 0.05) than that in treated rats (11.29 {+-} 1.01 mg). Linear regression between the BMC and bone fractional area, from 20 rats, showed a strong correlation (r{sup 2} = 0.70, p < 0.0001), indicating that the BMC can be used, in place of previous destructive analysis techniques, to characterize bone growth. The high precision (2.5%) of the micro-CT methodology indicates its utility in detecting small BMC changes in animals.

  8. SU-E-J-275: Review - Computerized PET/CT Image Analysis in the Evaluation of Tumor Response to Therapy

    International Nuclear Information System (INIS)

    Lu, W; Wang, J; Zhang, H

    2015-01-01

    Purpose: To review the literature in using computerized PET/CT image analysis for the evaluation of tumor response to therapy. Methods: We reviewed and summarized more than 100 papers that used computerized image analysis techniques for the evaluation of tumor response with PET/CT. This review mainly covered four aspects: image registration, tumor segmentation, image feature extraction, and response evaluation. Results: Although rigid image registration is straightforward, it has been shown to achieve good alignment between baseline and evaluation scans. Deformable image registration has been shown to improve the alignment when complex deformable distortions occur due to tumor shrinkage, weight loss or gain, and motion. Many semi-automatic tumor segmentation methods have been developed on PET. A comparative study revealed benefits of high levels of user interaction with simultaneous visualization of CT images and PET gradients. On CT, semi-automatic methods have been developed for only tumors that show marked difference in CT attenuation between the tumor and the surrounding normal tissues. Quite a few multi-modality segmentation methods have been shown to improve accuracy compared to single-modality algorithms. Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Predictive models based on machine learning technique have been constructed for correlating selected image features to response. These models showed improved performance compared to current methods using cutoff value of a single measurement for tumor response. Conclusion: This review showed that

  9. SU-E-J-275: Review - Computerized PET/CT Image Analysis in the Evaluation of Tumor Response to Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lu, W; Wang, J; Zhang, H [University of Maryland School of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: To review the literature in using computerized PET/CT image analysis for the evaluation of tumor response to therapy. Methods: We reviewed and summarized more than 100 papers that used computerized image analysis techniques for the evaluation of tumor response with PET/CT. This review mainly covered four aspects: image registration, tumor segmentation, image feature extraction, and response evaluation. Results: Although rigid image registration is straightforward, it has been shown to achieve good alignment between baseline and evaluation scans. Deformable image registration has been shown to improve the alignment when complex deformable distortions occur due to tumor shrinkage, weight loss or gain, and motion. Many semi-automatic tumor segmentation methods have been developed on PET. A comparative study revealed benefits of high levels of user interaction with simultaneous visualization of CT images and PET gradients. On CT, semi-automatic methods have been developed for only tumors that show marked difference in CT attenuation between the tumor and the surrounding normal tissues. Quite a few multi-modality segmentation methods have been shown to improve accuracy compared to single-modality algorithms. Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Predictive models based on machine learning technique have been constructed for correlating selected image features to response. These models showed improved performance compared to current methods using cutoff value of a single measurement for tumor response. Conclusion: This review showed that

  10. Psychophysical analysis of monitor display functions affecting observer diagnostic performance of CT image on liquid crystal display monitors

    International Nuclear Information System (INIS)

    Yamaguchi, M.; Fujita, H.; Asai, Y.; Uemura, M.; Ookura, Y.; Matsumoto, M.; Johkoh, T.

    2005-01-01

    The aim of the present study was to propose suitable display functions for CT image representation on liquid crystal display (LCD) monitors by analyzing the characteristics of the monitor's typical display functions using psychophysical analysis. The luminance of the LCD monitor was adjusted to a maximum of 275 cd/m 2 and 480 cd/m 2 . Three types of postcalibrated display functions (i.e., GSDF, CIELAB, and Exponential γ 2.2) were evaluated. Luminance calculation of a new grayscale test pattern (NGTP) was done for the conversion of the digital driving level (DDL) into the CT value. The psychophysical gradient δ of display functions for the CT value was evaluated and compared via statistical analysis. The δ value of GSDF and CIE decreased exponentially; however, the δ value of Exponential γ 2.2 showed a convex curve with a peak at a specific point. There was a statistically significant difference among the δ values of the three types of display functions on the 480 cd/m 2 maximum via Kruskal Wallis test (P<0.001). The GSDF was suitable for observation of abdominal and lung CT images; however, the display function combined the Exponential γ 2.2 and the GSDF functions and was ideal for observation of brain CT images by psychophysical analysis. (orig.)

  11. CT Analysis of the Anterior Mediastinum in Idiopathic Pulmonary Fibrosis and Nonspecific Interstitial Pneumonia

    International Nuclear Information System (INIS)

    Lee, Chang Hyun; Lee, Hyun Ju; Son, Kyu Ri; Chun, Eun Ju; Lim, Kun Young; Goo, Jin Mo; Im, Jung Gi; Heo, Jeong Nam; Song, Jae Woo

    2006-01-01

    We wanted to determine whether the amount and shape of the anterior mediastinal fat in the patients suffering with usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia (NSIP) was different from those of the normal control group. We selected patients who suffered with UIP (n 26) and NSIP (n = 26) who had undergone CT scans. Twenty-six controls were selected from individuals with normal CT findings and normal pulmonary function tests. All three groups (n = 78) were individually matched for age and gender. The amounts of anterior mediastinal fat, and the retrosternal anteroposterior (AP) and transverse dimensions of the anterior mediastinal fat were compared by one-way analysis of variance and Bonferroni's test. The shapes of the anterior mediastinum were compared using the Chi-square test. Exact logistic regression analysis and polychotomous logistic regression analysis were employed to assess whether the patients with NSIP or UIP had a tendency to show a convex shape of their anterior mediastinal fat. The amount of anterior mediastinal fat was not different among the three groups (p 0.175). For the UIP patients, the retrosternal AP dimension of the anterior mediastinal fat was shorter (p = 0.037) and the transverse dimension of the anterior mediastinal fat was longer (p = 0.001) than those of the normal control group. For the NSIP patients, only the transverse dimension was significantly longer than those of the normal control group (p < 0.001). The convex shape of the anterior mediastinum was predictive of NSIP (OR = 19.7, CI 3.32-∞, p < 0.001) and UIP (OR = 24.42, CI 4.06-∞, p < 0.001). For UIP patients, the retrosternal AP and transverse dimensions are different from those of normal individuals, whereas the amounts of anterior mediastinal fat are similar. UIP and NSIP patients have a tendency to have a convex shape of their anterior mediastinal fat

  12. CT Analysis of the Anterior Mediastinum in Idiopathic Pulmonary Fibrosis and Nonspecific Interstitial Pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Hyun; Lee, Hyun Ju; Son, Kyu Ri; Chun, Eun Ju; Lim, Kun Young; Goo, Jin Mo; Im, Jung Gi [Seoul National University College of Medicine, Seoul (Korea, Republic of); Heo, Jeong Nam; Song, Jae Woo [University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2006-09-15

    We wanted to determine whether the amount and shape of the anterior mediastinal fat in the patients suffering with usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia (NSIP) was different from those of the normal control group. We selected patients who suffered with UIP (n 26) and NSIP (n = 26) who had undergone CT scans. Twenty-six controls were selected from individuals with normal CT findings and normal pulmonary function tests. All three groups (n = 78) were individually matched for age and gender. The amounts of anterior mediastinal fat, and the retrosternal anteroposterior (AP) and transverse dimensions of the anterior mediastinal fat were compared by one-way analysis of variance and Bonferroni's test. The shapes of the anterior mediastinum were compared using the Chi-square test. Exact logistic regression analysis and polychotomous logistic regression analysis were employed to assess whether the patients with NSIP or UIP had a tendency to show a convex shape of their anterior mediastinal fat. The amount of anterior mediastinal fat was not different among the three groups (p 0.175). For the UIP patients, the retrosternal AP dimension of the anterior mediastinal fat was shorter (p = 0.037) and the transverse dimension of the anterior mediastinal fat was longer (p = 0.001) than those of the normal control group. For the NSIP patients, only the transverse dimension was significantly longer than those of the normal control group (p < 0.001). The convex shape of the anterior mediastinum was predictive of NSIP (OR = 19.7, CI 3.32-{infinity}, p < 0.001) and UIP (OR = 24.42, CI 4.06-{infinity}, p < 0.001). For UIP patients, the retrosternal AP and transverse dimensions are different from those of normal individuals, whereas the amounts of anterior mediastinal fat are similar. UIP and NSIP patients have a tendency to have a convex shape of their anterior mediastinal fat.

  13. Effects of alveolar bone displacement with segmental osteotomy: micro-CT and histomorphometric analysis in rats

    Directory of Open Access Journals (Sweden)

    Taegun KIM

    Full Text Available Abstract The purpose of this study was to evaluate the effects of segmental osteotomy on the blood vessels and osteoclasts in rats using micro-computed tomography (micro-CT and histomorphometric analysis. After segmental osteotomy was performed around the maxillary first molars of 36 male Sprague-Dawley rats (n = 72, the samples were divided into a control group (no displacement, 0.5 D group (0.5 mm buccal displacement and 1.0 D group (1.0 mm buccal displacement (n = 24/group. At 1, 2, 4 and 8 weeks after surgery, changes in the blood vessel volume were investigated using micro-CT with perfusion of radiopaque silicone rubber. Tartrate-resistant acid phosphatase (TRAP staining was used for histomorphometric analysis. Two-way repeated measures analysis of variance (rmANOVA was performed to compare the volume of blood vessels and number of TRAP-positive osteoclasts among the groups. Regarding blood vessel volume, the displacement groups had no significant effects, while the time points had significant effects (p = 0.014. The blood vessel volume at 1 week was significantly smaller than that at 2, 4, and 8 weeks (p = 0.004, p = 0.026, and p = 0.005, respectively. Regarding TRAP cell count, the displacement groups had no significant effects, while the time points had significant effects (p < 0.001. The number of TRAP-positive osteoclasts at 8 weeks was significantly smaller than that at 1, 2, and 4 weeks (p < 0.001, p < 0.001, and p = 0.002, respectively, and the count at 4 weeks was smaller than that at 1 week (p = 0.011. Therefore, a regional osteoclast-related acceleratory phenomenon was maintained until 4 weeks after surgery.

  14. Toward automatic regional analysis of pulmonary function using inspiration and expiration thoracic CT

    DEFF Research Database (Denmark)

    Murphy, Keelin; Pluim, Josien P. W.; Rikxoort, Eva M. van

    2012-01-01

    and its results; (b) verify that the quantitative, regional ventilation measurements acquired through CT are meaningful for pulmonary function analysis; (c) identify the most effective of the calculated measurements in predicting pulmonary function; and (d) demonstrate the potential of the system...... disorder). Lungs, fissures, airways, lobes, and vessels are automatically segmented in both scans and the expiration scan is registered with the inspiration scan using a fully automatic nonrigid registration algorithm. Segmentations and registrations are examined and scored by expert observers to analyze...... to have good correlation with spirometry results, with several having correlation coefficients, r, in the range of 0.85–0.90. The best performing kNN classifier succeeded in classifying 67% of subjects into the correct COPD GOLD stage, with a further 29% assigned to a class neighboring the correct one...

  15. Analysis of the cardiac motion in myocardial infarction by the ECG-synchronized CT

    International Nuclear Information System (INIS)

    Watanabe, Shigeru; Shimizu, Masahiko; Yoshida, Hideo; Morooka, Nobuhiro; Shukuya, Masaki

    1981-01-01

    The cardiac motion in patients with myocardial infarction was analyzed by the ECG-synchronized computed tomography (CT). For ECG synchronization, the ECG gating method and the data sorting method were used. By the ECG gating method, the gated cardiac images during 0.1 msec intervals at end-diastolic and the end-systolic phases were obtained. By the data sorting method, phasic CT images were reconstructed retrospectively by selecting appropriate data from a series of consecutive scans taken with simultaneous continuous ECG recordings. Six normal subjects and eight patients with myocardial infarction were studied by the ECG gating method, and 14 normal subjects and 25 patients with myocardial infarction were studied by the data sorting method. The end-diastolic and the end-systolic pictures at mid left ventricular level were superimposed and the cardiac borders were traced for the analysis (Fig. 4). Then the cardiac cross-sectional areas at each cardiac phase (40 msec) were calculated, and a cardiac area curve was obtained by plotting them consecutively. The cross-sectional images were divided into right anterior, right posterior, left anterior and left posterior segments. Cardiac area curves of the each segment were also obtained for further analysis. From these curves, the changing ratio of cardiac areas (maximum area - minimum area/maximum area) and the maximum area velocity in systole and diastole were calculated. On the images and the cardiac area curves in myocardial infarction patients, abnormal myocardial movements such as partial akinesis, hypokinesis or paradoxical movement were apparent asd the area of abnormal motions corresponded well with the location of infarction determined by ECG, RI scanning and angiography. A decrease of the changing ratio and the velocity in the infarction area were shown (Fig. 6, 7) and the functional disturbances were suggested during not only systole but diastole also. (author)

  16. Diagnostic accuracy of 64 multislice CT angiography in the assessment of coronary in-stent restenosis: A meta-analysis

    International Nuclear Information System (INIS)

    Sun Zhonghua; Almutairi, Abdulrahman Marzouq D.

    2010-01-01

    Purpose: The aim of this study was to perform a meta-analysis of the diagnostic accuracy of 64-slice CT angiography for the detection of coronary in-stent restenosis in patients treated with coronary stents when compared to conventional coronary angiography. Materials and methods: A search of PUBMED/MEDLINE, ProQuest and Cochrane library databases for English literature was performed. Only studies comparing 64-slice CT angiography with conventional coronary angiography for the detection of coronary in-stent restenosis (more than 50% stenosis) were included for analysis. Sensitivity and specificity estimates pooled across studies were tested using a fixed effects model. Results: Fourteen studies met selection criteria for inclusion in the analysis. The mean value of assessable stents was 89%. Prevalence of in-stent restenosis following coronary stenting was 20% among these studies. Pooled estimates of the sensitivity and specificity of overall 64-slice CT angiography for the detection of coronary in-stent restenosis was 90% (95% CI: 86%, 94%) and 91% (95% CI: 90%, 93%), respectively, based on the evaluation of assessable stents. Diagnostic value of 64-slice CT angiography was found to decrease significantly when the analysis was performed with inclusion of nonassessable segments in five studies, with pooled sensitivity and specificity being 79% (95% CI: 68%, 88%) and 81% (95% CI: 77%, 84%). Stent diameter is the main factor affecting the diagnostic value of 64-slice CT angiography. Conclusion: Our results showed that 64-slice CT angiography has high diagnostic value (both sensitivity and specificity) for detection of coronary in-stent restenosis based on assessable segments when compared to conventional coronary angiography.

  17. Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

    International Nuclear Information System (INIS)

    Hinzpeter, Ricarda; Sprengel, Kai; Wanner, Guido A.; Mildenberger, Peter; Alkadhi, Hatem

    2017-01-01

    Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

  18. Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

    Energy Technology Data Exchange (ETDEWEB)

    Hinzpeter, Ricarda, E-mail: Ricarda.Hinzpeter@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland); Sprengel, Kai, E-mail: Kai.Sprengel@usz.ch [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Wanner, Guido A., E-mail: Guido.Wanner@sbk-vs.de [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Department of General Surgery, Schwarzwald-Baar Klinikum, University of Freiburg, Klinikstr. 11, D-78052 Villingen-Schwenningen (Germany); Mildenberger, Peter, E-mail: peter.mildenberger@unimedizin-mainz.de [Department of Diagnostic and Interventional Radiology, University Hospital of Mainz, Langenbeckstr. 1, D-55131 Mainz (Germany); Alkadhi, Hatem, E-mail: hatem.alkadhi@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland)

    2017-03-15

    Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

  19. Clinical and CT analysis of GCS 15 patients with intracranial hemorrhage

    International Nuclear Information System (INIS)

    Yang Lin; He Jianyuan; Jiang Shanyue; Zhang Yanling

    2007-01-01

    Objective: To analyze the clinical symptoms and CT manifestations of GCS 15 patients with intracranial hemorrhage. Methods: Clinical data and manifestations of the CT images of 35 patients with GCS 15 and intracranial hemorrhage were retrospectively analyzed and followed up. in short term. Results: Clinical symptoms: Deficits in short-term memory appeared in 17% of patients, vomiting in 26%, headache in 97%, physical evidence of trauma above the clavicles in 100%. CT scanning: intracerebral hemorrhage occurred in 18 patients, epidural hemorrhage in 9 patients, subarachnoid hemorrhage in 8 patients, subdural hemorrhage in 7 patients. During follow up, clinical severe degree was in consistent of craniocerebral CT scanning. Conclusion: For patients with GCS 15 brain injuries early head CT scanning is very important. Intracranial hemorrhage may occur in these patients. If possible, re-assessment of clinical examination and CT scanning is remarkably necessary. (authors)

  20. Analysis on misdiagnosis of 35 patients with pulmonary tuberculosis on CT films

    International Nuclear Information System (INIS)

    Li Tieyi; Ji Jingling; Ge Li

    2000-01-01

    Objective: To investigate CT characteristics of pulmonary tuberculosis by analyzing the reasons of misdiagnosis in 35 patients with pulmonary tuberculosis. Methods: The patients in this study included 19 men and 16 women, with ages ranging from 18 to 79 years old. Chest CT scans were performed in all patients. The CT films were reviewed retrospectively by two senior radiologists and were correlated with pathologic findings. The misdiagnosing reasons were analyzed. Results: Misdiagnoses as lung cancer were made in 29 cases, pneumonia in 4 cases, and other diseases in 2 cases. The lesions on CT films appeared as nodules and masses in 14 cases, pulmonary segmental and lobar shadows in 19 cases, and hilar and mediastinal masses in 2 cases. Conclusion: The main causes of misdiagnosis for pulmonary tuberculosis are atypical radiological appearance on CT films, inadequate visualized lesions, and lacking of combination of CT findings with that of chest radiography

  1. The CT manifestations and clinical analysis of traumatic cerebral infarction in children

    International Nuclear Information System (INIS)

    Zhang Tianbo; Lin Shunfa; Huang Xiaohui; Xiao Zhe; Lu Sifang

    2004-01-01

    Objective: To evaluate pathogenesis, CT manifestations, diagnosis and treatment, and prognosis of traumatic cerebral infarction in children. Methods: Axial head CT scanning was performed in 35 cases, meanwhile the treatment included vessel dilatation, anti-spasm, nerve nourishment and anti-coagulation. Results: The traumatic cerebral infarction in children was commonly located in the basal ganglia. CT scan revealed low dense lesions in all cases. 33 patients out of 35 convalesced gradually, when no anomaly was shown on CT. The rest 2 patients improved, whose lesions decreased in size on CT images. Conclusion: The major pathophysiology of traumatic cerebral infarction in children is occlusion of cerebral microcirculation and convulsion of vein after trauma. CT scan and follow-up are of great value in monitoring the damages. Early diagnosis and treatment result in good prognosis

  2. Interventional heart wall motion analysis with cardiac C-arm CT systems

    International Nuclear Information System (INIS)

    Müller, Kerstin; Maier, Andreas K; Schwemmer, Chris; Hornegger, Joachim; Zheng, Yefeng; Wang, Yang; Lauritsch, Günter; Rohkohl, Christopher; Fahrig, Rebecca

    2014-01-01

    Today, quantitative analysis of three-dimensional (3D) dynamics of the left ventricle (LV) cannot be performed directly in the catheter lab using a current angiographic C-arm system, which is the workhorse imaging modality for cardiac interventions. Therefore, myocardial wall analysis is completely based on the 2D angiographic images or pre-interventional 3D/4D imaging. In this paper, we present a complete framework to study the ventricular wall motion in 4D (3D+t) directly in the catheter lab. From the acquired 2D projection images, a dynamic 3D surface model of the LV is generated, which is then used to detect ventricular dyssynchrony. Different quantitative features to evaluate LV dynamics known from other modalities (ultrasound, magnetic resonance imaging) are transferred to the C-arm CT data. We use the ejection fraction, the systolic dyssynchrony index a 3D fractional shortening and the phase to maximal contraction (ϕ i, max ) to determine an indicator of LV dyssynchrony and to discriminate regionally pathological from normal myocardium. The proposed analysis tool was evaluated on simulated phantom LV data with and without pathological wall dysfunctions. The LV data used is publicly available online at https://conrad.stanford.edu/data/heart. In addition, the presented framework was tested on eight clinical patient data sets. The first clinical results demonstrate promising performance of the proposed analysis tool and encourage the application of the presented framework to a larger study in clinical practice. (paper)

  3. Nondestructive Analysis of Astromaterials by Micro-CT and Micro-XRF Analysis for PET Examination

    Science.gov (United States)

    Zeigler, R. A.; Righter, K.; Allen, C. C.

    2013-01-01

    An integral part of any sample return mission is the initial description and classification of returned samples by the preliminary examination team (PET). The goal of the PET is to characterize and classify returned samples and make this information available to the larger research community who then conduct more in-depth studies on the samples. The PET tries to minimize the impact their work has on the sample suite, which has in the past limited the PET work to largely visual, nonquantitative measurements (e.g., optical microscopy). More modern techniques can also be utilized by a PET to nondestructively characterize astromaterials in much more rigorous way. Here we discuss our recent investigations into the applications of micro-CT and micro-XRF analyses with Apollo samples and ANSMET meteorites and assess the usefulness of these techniques in future PET. Results: The application of micro computerized tomography (micro-CT) to astromaterials is not a new concept. The technique involves scanning samples with high-energy x-rays and constructing 3-dimensional images of the density of materials within the sample. The technique can routinely measure large samples (up to approx. 2700 cu cm) with a small individual voxel size (approx. 30 cu m), and has the sensitivity to distinguish the major rock forming minerals and identify clast populations within brecciated samples. We have recently run a test sample of a terrestrial breccia with a carbonate matrix and multiple igneous clast lithologies. The test results are promising and we will soon analyze a approx. 600 g piece of Apollo sample 14321 to map out the clast population within the sample. Benchtop micro x-ray fluorescence (micro-XRF) instruments can rapidly scan large areas (approx. 100 sq cm) with a small pixel size (approx. 25 microns) and measure the (semi) quantitative composition of largely unprepared surfaces for all elements between Be and U, often with sensitivity on the order of a approx. 100 ppm. Our recent

  4. Comparision between Brain Atrophy and Subdural Volume to Predict Chronic Subdural Hematoma: Volumetric CT Imaging Analysis.

    Science.gov (United States)

    Ju, Min-Wook; Kim, Seon-Hwan; Kwon, Hyon-Jo; Choi, Seung-Won; Koh, Hyeon-Song; Youm, Jin-Young; Song, Shi-Hun

    2015-10-01

    Brain atrophy and subdural hygroma were well known factors that enlarge the subdural space, which induced formation of chronic subdural hematoma (CSDH). Thus, we identified the subdural volume that could be used to predict the rate of future CSDH after head trauma using a computed tomography (CT) volumetric analysis. A single institution case-control study was conducted involving 1,186 patients who visited our hospital after head trauma from January 1, 2010 to December 31, 2014. Fifty-one patients with delayed CSDH were identified, and 50 patients with age and sex matched for control. Intracranial volume (ICV), the brain parenchyme, and the subdural space were segmented using CT image-based software. To adjust for variations in head size, volume ratios were assessed as a percentage of ICV [brain volume index (BVI), subdural volume index (SVI)]. The maximum depth of the subdural space on both sides was used to estimate the SVI. Before adjusting for cranium size, brain volume tended to be smaller, and subdural space volume was significantly larger in the CSDH group (p=0.138, p=0.021, respectively). The BVI and SVI were significantly different (p=0.003, p=0.001, respectively). SVI [area under the curve (AUC), 77.3%; p=0.008] was a more reliable technique for predicting CSDH than BVI (AUC, 68.1%; p=0.001). Bilateral subdural depth (sum of subdural depth on both sides) increased linearly with SVI (pSubdural space volume was significantly larger in CSDH groups. SVI was a more reliable technique for predicting CSDH. Bilateral subdural depth was useful to measure SVI.

  5. Automatic CT-based finite element model generation for temperature-based death time estimation: feasibility study and sensitivity analysis.

    Science.gov (United States)

    Schenkl, Sebastian; Muggenthaler, Holger; Hubig, Michael; Erdmann, Bodo; Weiser, Martin; Zachow, Stefan; Heinrich, Andreas; Güttler, Felix Victor; Teichgräber, Ulf; Mall, Gita

    2017-05-01

    Temperature-based death time estimation is based either on simple phenomenological models of corpse cooling or on detailed physical heat transfer models. The latter are much more complex but allow a higher accuracy of death time estimation, as in principle, all relevant cooling mechanisms can be taken into account.Here, a complete workflow for finite element-based cooling simulation is presented. The following steps are demonstrated on a CT phantom: Computer tomography (CT) scan Segmentation of the CT images for thermodynamically relevant features of individual geometries and compilation in a geometric computer-aided design (CAD) model Conversion of the segmentation result into a finite element (FE) simulation model Computation of the model cooling curve (MOD) Calculation of the cooling time (CTE) For the first time in FE-based cooling time estimation, the steps from the CT image over segmentation to FE model generation are performed semi-automatically. The cooling time calculation results are compared to cooling measurements performed on the phantoms under controlled conditions. In this context, the method is validated using a CT phantom. Some of the phantoms' thermodynamic material parameters had to be determined via independent experiments.Moreover, the impact of geometry and material parameter uncertainties on the estimated cooling time is investigated by a sensitivity analysis.

  6. High-resolution dynamic imaging and quantitative analysis of lung cancer xenografts in nude mice using clinical PET/CT.

    Science.gov (United States)

    Wang, Ying Yi; Wang, Kai; Xu, Zuo Yu; Song, Yan; Wang, Chu Nan; Zhang, Chong Qing; Sun, Xi Lin; Shen, Bao Zhong

    2017-08-08

    Considering the general application of dedicated small-animal positron emission tomography/computed tomography is limited, an acceptable alternative in many situations might be clinical PET/CT. To estimate the feasibility of using clinical PET/CT with [F-18]-fluoro-2-deoxy-D-glucose for high-resolution dynamic imaging and quantitative analysis of cancer xenografts in nude mice. Dynamic clinical PET/CT scans were performed on xenografts for 60 min after injection with [F-18]-fluoro-2-deoxy-D-glucose. Scans were reconstructed with or without SharpIR method in two phases. And mice were sacrificed to extracting major organs and tumors, using ex vivo γ-counting as a reference. Strikingly, we observed that the image quality and the correlation between the all quantitive data from clinical PET/CT and the ex vivo counting was better with the SharpIR reconstructions than without. Our data demonstrate that clinical PET/CT scanner with SharpIR reconstruction is a valuable tool for imaging small animals in preclinical cancer research, offering dynamic imaging parameters, good image quality and accurate data quatification.

  7. Automation process for morphometric analysis of volumetric CT data from pulmonary vasculature in rats.

    Science.gov (United States)

    Shingrani, Rahul; Krenz, Gary; Molthen, Robert

    2010-01-01

    With advances in medical imaging scanners, it has become commonplace to generate large multidimensional datasets. These datasets require tools for a rapid, thorough analysis. To address this need, we have developed an automated algorithm for morphometric analysis incorporating A Visualization Workshop computational and image processing libraries for three-dimensional segmentation, vascular tree generation and structural hierarchical ordering with a two-stage numeric optimization procedure for estimating vessel diameters. We combine this new technique with our mathematical models of pulmonary vascular morphology to quantify structural and functional attributes of lung arterial trees. Our physiological studies require repeated measurements of vascular structure to determine differences in vessel biomechanical properties between animal models of pulmonary disease. Automation provides many advantages including significantly improved speed and minimized operator interaction and biasing. The results are validated by comparison with previously published rat pulmonary arterial micro-CT data analysis techniques, in which vessels were manually mapped and measured using intense operator intervention. Published by Elsevier Ireland Ltd.

  8. CT abnormality in multiple sclerosis analysis based on 28 probable cases and correlation with clinical manifestations

    International Nuclear Information System (INIS)

    Kakigi, Ryusuke; Shibasaki, Hiroshi; Tabira, Takeshi; Kuroiwa, Yoshigoro; Numaguchi, Yuji.

    1981-01-01

    In order to investigate the occurrence and nature of CT abnormality and its correlation with clinical manifestations in multiple sclerosis, 34 CT records obtained from 28 consecutive patients with probable multiple sclerosis were reviewed. Forty-six percent of all cases showed abnormal CT. Dilatation of cortical sulci was found in 39%; dilatation of the lateral ventricle in 36%; dilatation of prepontine or cerebello-pontine cistern and the fourth ventricle, suggesting brainstem atrophy, in 18%; dilatation of cerebellar sulci, superior cerebellar cistern and cisterna magna, suggesting cerebellar atrophy, in 11%. Low density area was found in the cerebral hemisphere in 11% of cases. Contrast enhancement, performed on 25 CT records, did not show any change. There was no correlation between CT abnormality and duration of the illness. Although abnormal CT tended to occur more frequently during exacerbations and chronic stable state than during remissions, the difference was not statistically significant. CT abnormalities suggesting brainstem atrophy, cerebellar atrophy or plaques were found exclusively during exacerbations and chronic stable state. The occurrence of CT abnormalities was not significantly different among various clinical forms which were classified based on clinically estimated sites of lesion, except that abnormal CT tended to occur less frequently in cases classified as the optic-spinal form. It is noteworthy that cerebral cortical atrophy and/or dilatation of the lateral ventricle were found in 31% of cases who did not show any clinical sign of cerebral involvement. There was a statistically significant correlation between CT abnormalities and levels of clinical disability. Eighty percent of the bedridden or severely disabled patients showed abnormal CT, in contrast with only 29% of those with moderate, slight or no disability. (author)

  9. CT abnormality in multiple sclerosis analysis based on 28 probable cases and correlation with clinical manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Kakigi, R.; Shibasaki, H.; Tabira, T.; Kuroiwa, Y. (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine); Numaguchi, Y.

    1981-10-01

    In order to investigate the occurrence and nature of CT abnormality and its correlation with clinical manifestations in multiple sclerosis, 34 CT records obtained from 28 consecutive patients with probable multiple sclerosis were reviewed. Forty-six percent of all cases showed abnormal CT. Dilatation of cortical sulci was found in 39%; dilatation of the lateral ventricle in 36%; dilatation of prepontine or cerebello-pontine cistern and the fourth ventricle, suggesting brainstem atrophy, in 18%; dilatation of cerebellar sulci, superior cerebellar cistern and cisterna magna, suggesting cerebellar atrophy, in 11%. Low density area was found in the cerebral hemisphere in 11% of cases. Contrast enhancement, performed on 25 CT records, did not show any change. There was no correlation between CT abnormality and duration of the illness. Although abnormal CT tended to occur more frequently during exacerbations and chronic stable state than during remissions, the difference was not statistically significant. CT abnormalities suggesting brainstem atrophy, cerebellar atrophy or plaques were found exclusively during exacerbations and chronic stable state. The occurrence of CT abnormalities was not significantly different among various clinical forms which were classified based on clinically estimated sites of lesion, except that abnormal CT tended to occur less frequently in cases classified as the optic-spinal form. It is noteworthy that cerebral cortical atrophy and/or dilatation of the lateral ventricle were found in 31% of cases who did not show any clinical sign of cerebral involvement. There was a statistically significant correlation between CT abnormalities and levels of clinical disability. Eighty percent of the bedridden or severely disabled patients showed abnormal CT, in contrast with only 29% of those with moderate, slight or no disability.

  10. Cost-effectiveness analysis of PET-CT-guided management for locally advanced head and neck cancer.

    Science.gov (United States)

    Smith, A F; Hall, P S; Hulme, C T; Dunn, J A; McConkey, C C; Rahman, J K; McCabe, C; Mehanna, H

    2017-11-01

    A recent large United Kingdom (UK) clinical trial demonstrated that positron-emission tomography-computed tomography (PET-CT)-guided administration of neck dissection (ND) in patients with advanced head and neck cancer after primary chemo-radiotherapy treatment produces similar survival outcomes to planned ND (standard care) and is cost-effective over a short-term horizon. Further assessment of long-term outcomes is required to inform a robust adoption decision. Here we present results of a lifetime cost-effectiveness analysis of PET-CT-guided management from a UK secondary care perspective. Initial 6-month cost and health outcomes were derived from trial data; subsequent incidence of recurrence and mortality was simulated using a de novo Markov model. Health benefit was measured in quality-adjusted life years (QALYs) and costs reported in 2015 British pounds. Model parameters were derived from trial data and published literature. Sensitivity analyses were conducted to assess the impact of uncertainty and broader National Health Service (NHS) and personal social services (PSS) costs on the results. PET-CT management produced an average per-person lifetime cost saving of £1485 and an additional 0.13 QALYs. At a £20,000 willingness-to-pay per additional QALY threshold, there was a 75% probability that PET-CT was cost-effective, and the results remained cost-effective over the majority of sensitivity analyses. When adopting a broader NHS and PSS perspective, PET-CT management produced an average saving of £700 and had an 81% probability of being cost-effective. This analysis indicates that PET-CT-guided management is cost-effective in the long-term and supports the case for wide-scale adoption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Atherosclerotic plaque composition: analysis with multicolor CT and targeted gold nanoparticles

    NARCIS (Netherlands)

    Cormode, David P.; Roessl, Ewald; Thran, Axel; Skajaa, Torjus; Gordon, Ronald E.; Schlomka, Jens-Peter; Fuster, Valentin; Fisher, Edward A.; Mulder, Willem J. M.; Proksa, Roland; Fayad, Zahi A.

    2010-01-01

    To investigate the potential of spectral computed tomography (CT) (popularly referred to as multicolor CT), used in combination with a gold high-density lipoprotein nanoparticle contrast agent (Au-HDL), for characterization of macrophage burden, calcification, and stenosis of atherosclerotic

  12. Variance analysis of x-ray CT sinograms in the presence of electronic noise background.

    Science.gov (United States)

    Ma, Jianhua; Liang, Zhengrong; Fan, Yi; Liu, Yan; Huang, Jing; Chen, Wufan; Lu, Hongbing

    2012-07-01

    Low-dose x-ray computed tomography (CT) is clinically desired. Accurate noise modeling is a fundamental issue for low-dose CT image reconstruction via statistics-based sinogram restoration or statistical iterative image reconstruction. In this paper, the authors analyzed the statistical moments of low-dose CT data in the presence of electronic noise background. The authors first studied the statistical moment properties of detected signals in CT transmission domain, where the noise of detected signals is considered as quanta fluctuation upon electronic noise background. Then the authors derived, via the Taylor expansion, a new formula for the mean-variance relationship of the detected signals in CT sinogram domain, wherein the image formation becomes a linear operation between the sinogram data and the unknown image, rather than a nonlinear operation in the CT transmission domain. To get insight into the derived new formula by experiments, an anthropomorphic torso phantom was scanned repeatedly by a commercial CT scanner at five different mAs levels from 100 down to 17. The results demonstrated that the electronic noise background is significant when low-mAs (or low-dose) scan is performed. The influence of the electronic noise background should be considered in low-dose CT imaging.

  13. Degenerative osteoarthritis of atlanto-odontoid joint: CT findings and clinical analysis

    International Nuclear Information System (INIS)

    Xu Aide; Wang Song; Mao Yunhua

    1998-01-01

    Purpose: To analyze the CT appearances and clinical aspects of the degeneration at atlanto-odontoid(A-O) joint. Methods: Thin section axial CT scans, of AO joints were studied in 317 consecutive patients who underwent brain or cervical spine CT examinations. The images were viewed using double-blind method. Observation included: osteophytosis, changes of joint space and transverse ligament, and the clinical symptoms as well. Results: CT findings of AO joint degeneration included: formation of osteophyte, narrowing of joint space, transverse ligament calcification, and joint vacuum phenomenon. Among individuals above 40 years of age, the incidence of degeneration at AO joint went up gradually (P<0.01). Conclusion: Degeneration of AO joint was not uncommon among aged people, CT could better demonstrate the pathological changes

  14. Evolution of traumatic intracerebral hematoma. Analysis of sequential CT scans since per-acute stage

    Energy Technology Data Exchange (ETDEWEB)

    Nagaseki, Yoshishige; Horikoshi, Satoru [Gunma Univ., Maebashi (Japan). School of Medicine; Tamura, Masaru

    1984-05-01

    To clarify the evolution of traumatic intracerebral hematoma (TICH), initial computerized tomography (CT) scans of 28 TICH cases performed within one hour after head trauma were studied along with their follow-up CT scans. They were classified into the following two groups; per-acute group included seven cases in which TICH was completed on the initial CT scans taken within one hour after head injury and acute group included 21 cases in which the initial CT scans revealed isodensity or high density spot and repeat CT scans disclosed TICH by 48 hours after injury. In the per-acute group, initial CT scans showed a homogeneous, well defined, and high density mass (1.5-6.5 cm in diameter). In sequential CT scans of the three cases, the hematoma did not increase but spontaneously disappeared. Other four cases died early after head trauma. Their initial CT scans revealed a large high density mass (3-6.5 cm in diameter) combined with other extracerebral hemorrhages. In the acute group, initial CT scans demonstrated isodensity or high density spot and sequential CT scans showed mottled appearance of salt and pepper appearance, and after a while showed fusion of small high density areas to become a massive high density area (contusional hematoma) by 48 hours after injury. In six cases of this group, the contusional hematoma was removed within 24 hours after injury and in one case at 3.5 days. In other 14 cases, the hematomas shrank or disappeared spontaneously. From these results, it was considered that evolution of TICH's were classified into the two groups; per-acute group resulting from rupture of vessels and acute group resulting from contusion.

  15. Multidetector-row helical CT: analysis of time management and workflow

    Energy Technology Data Exchange (ETDEWEB)

    Roos, Justus E.; Desbiolles, Lotus M.; Willmann, Juergen K.; Weishaupt, Dominik; Marincek, Borut; Hilfiker, Paul R. [Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland)

    2002-03-01

    The purpose of this study was to evaluate time management and workflow for multidetector-row helical CT (MDCT). Time for patient and data handling of at total of 580 patients were evaluated at two different time periods (December 1999, August 2000), each for the following baseline measurements: (a) change of clothes/instruction; (b) patient placement on the CT table/i.v. catheter; (c) CT planning and programming; (d) CT data acquisition; (e) CT data reconstruction; (f) CT data storage/printing. All imaging was performed on a Somatom Volume Zoom (Siemens, Erlangen, Germany). Time measurements summarized for different CT protocols revealed the following: (a) 5:01 min ({+-}2.06 min); (b) 4:36 min ({+-}2.43 min); (c) 4:11 min ({+-}2.55 min); (d) 0:43 min ({+-}0.15 min); (e) 6:59 min ({+-}2.39 min); (f) 09:51 min ({+-}3.51 min). Planning and programming was most time-consuming for CT angiography, whereas chest and abdominal CT needed only 3:26 and 3:30 min, respectively. Reconstruction time was highest for HRCT (9:22 min) and CTA (9:03 min). Data storage/printing was most time-consuming for HRCT (13:02 min), followed by combined neck-chest-abdomen examinations (12:19 min). Comparing the two time periods, during which a software update was performed, a mean time reduction of 4:31 min per patient (15%, p<0.001) was achieved. Whereas CT data acquisition time is no longer a problem with MDCT, patient management, data reconstruction, and data storage are the most time-consuming parts. Well-trained technicians, state-of-the-art workstations, and fast networking are the most important factors to improve workflow. (orig.)

  16. Optimization of oncological {sup 18}F-FDG PET/CT imaging based on a multiparameter analysis

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Vinicius O., E-mail: vinicius@radtec.com.br [Nuclear Medicine Department, São Rafael Hospital, Salvador 41720-375, Brazil and Nuclear Medicine Department, Hospital das Clínicas da Universidade Federal de Pernambuco/Ebserh, Recife 50670-901 (Brazil); Machado, Marcos A. D. [Nuclear Medicine Department, São Rafael Hospital, Salvador 41720-375, Brazil and Nuclear Medicine Department, Hospital das Clínicas da Universidade Federal de Bahia/Ebserh, Salvador 40110-060 (Brazil); Queiroz, Cleiton C. [Nuclear Medicine Department, São Rafael Hospital, Salvador 41720-375, Brazil and Nuclear Medicine Department, Hospital Universitário Professor Alberto Antunes/Ebserh, Maceió 57072-900 (Brazil); Souza, Susana O. [Department of Physics, Universidade Federal de Sergipe, São Cristóvão 49100-000 (Brazil); D’Errico, Francesco [Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520 and School of Engineering, University of Pisa, Pisa 56126 (Italy); Namías, Mauro [Fundación Centro Diagnóstico Nuclear, Buenos Aires C1417CVE (Argentina); Larocca, Ticiana F. [Centro de Biotecnologia e Terapia Celular, São Rafael Hospital, Salvador 41253-190 (Brazil); Soares, Milena B. P. [Centro de Biotecnologia e Terapia Celular, São Rafael Hospital, Salvador 41253-190, Brazil and Fundação Oswaldo Cruz, Centro de Pesq. Gonçalo Moniz, Salvador 40296-710 (Brazil)

    2016-02-15

    Purpose: This paper describes a method to achieve consistent clinical image quality in {sup 18}F-FDG scans accounting for patient habitus, dose regimen, image acquisition, and processing techniques. Methods: Oncological PET/CT scan data for 58 subjects were evaluated retrospectively to derive analytical curves that predict image quality. Patient noise equivalent count rate and coefficient of variation (CV) were used as metrics in their analysis. Optimized acquisition protocols were identified and prospectively applied to 179 subjects. Results: The adoption of different schemes for three body mass ranges (<60 kg, 60–90 kg, >90 kg) allows improved image quality with both point spread function and ordered-subsets expectation maximization-3D reconstruction methods. The application of this methodology showed that CV improved significantly (p < 0.0001) in clinical practice. Conclusions: Consistent oncological PET/CT image quality on a high-performance scanner was achieved from an analysis of the relations existing between dose regimen, patient habitus, acquisition, and processing techniques. The proposed methodology may be used by PET/CT centers to develop protocols to standardize PET/CT imaging procedures and achieve better patient management and cost-effective operations.

  17. Diagnostic value of [18F] FDG-PET and PET/CT in urinary bladder cancer: a meta-analysis.

    Science.gov (United States)

    Zhang, Huojun; Xing, Wei; Kang, Qinqin; Chen, Chao; Wang, Linhui; Lu, Jianping

    2015-05-01

    An early diagnosis of urinary bladder cancer is crucial for early treatment and management. The objective of this systematic review was to assess the overall diagnostic accuracy of 18 F FDG-PET and PET/CT in urinary bladder cancer with meta-analysis. The PubMed and CNKI databases were searched for the eligible studies published up to June 01, 2014. The sensitivity, specificity, and other measures of accuracy of 18 F FDG-PET and PET/CT in the diagnosis of urinary bladder cancer were pooled along with 95 % confidence intervals (CI). Summary receiver operating characteristic (ROC) curves were used to summarize overall test performance. Ten studies met our inclusion criteria. The summary estimates for 18 F FDG-PET and PET/CT in the diagnosis of urinary bladder cancer in meta-analysis were as follows: a pooled sensitivity, 0.82 (95 % confidence interval [CI], 0.75 to 0.88); a pooled specificity, 0.92 (95 % CI, 0.87 to 0.95); positive likelihood ratio, 6.80 (95 % CI, 4.31 to 10.74); negative likelihood ratio, 0.27 (95 % CI, 0.19 to 0.36); and diagnostic odds ratio, 25.18 (95 % CI, 17.58 to 70.4). The results indicate that 18 F FDG-PET and PET/CT are relatively high sensitive and specific for the diagnosis of urinary bladder cancer.

  18. Endobronchial valves in severe emphysematous patients: CT evaluation of lung fissures completeness, treatment radiological response and quantitative emphysema analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koenigkam-Santos, Marcel, E-mail: marcelk46@yahoo.com.br, E-mail: marcelk46@usp.b [Universidade de Sao Paulo (HCFMRP/USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas da Faculdade de Medicina; Paula, Wagner Diniz de [University of Brasilia (UnB), DF (Brazil). Brasilia University Hospital; Gompelmann, Daniela [University of Heidelberg (Germany). Department of Pneumology and Respiratory Medicine of the Chest Clinic (Thoraxklinik); Kauczor, Hans-Ulrich [University of Heidelberg (Germany). Department of Diagnostic and Interventional Radiology; Heussel, Claus Peter; Puderbach, Michael [University of Heidelberg (Germany). Department of Diagnostic and Interventional Radiology with Nuclear Medicine of the Chest Clinic (Thoraxklinik)

    2013-01-15

    Objective: To evaluate lung fissures completeness, post-treatment radiological response and quantitative CT analysis (QCTA) in a population of severe emphysematous patients submitted to endobronchial valves (EBV) implantation. Materials and Methods: Multi-detectors CT exams of 29 patients were studied, using thin-section low dose protocol without contrast. Two radiologists retrospectively reviewed all images in consensus; fissures completeness was estimated in 5% increments and post-EBV radiological response (target lobe atelectasis/volume loss) was evaluated. QCTA was performed in pre and post-treatment scans using a fully automated software. Results: CT response was present in 16/29 patients. In the negative CT response group, all 13 patients presented incomplete fissures, and mean oblique fissures completeness was 72.8%, against 88.3% in the other group. QCTA most significant results showed a reduced post-treatment total lung volume (LV) (mean 542 ml), reduced EBV-submitted LV (700 ml) and reduced emphysema volume (331.4 ml) in the positive response group, which also showed improved functional tests. Conclusion: EBV benefit is most likely in patients who have complete interlobar fissures and develop lobar atelectasis. In patients with no radiological response we observed a higher prevalence of incomplete fissures and a greater degree of incompleteness. The fully automated QCTA detected the post-treatment alterations, especially in the treated lung analysis. (author)

  19. 18F-FDG-PET/CT in the diagnosis of paraneoplastic neurological syndromes: a retrospective analysis

    International Nuclear Information System (INIS)

    Bannas, Peter; Weber, Christoph; Adam, Gerhard; Derlin, Thorsten; Lambert, Joerg; Mester, Janos; Klutmann, Susanne; Leypoldt, Frank

    2010-01-01

    Paraneoplastic neurological syndromes (PNS) constitute a challenging diagnostic problem, as the underlying tumour often remains unidentified for a long time, even with frequent conventional diagnostic procedures. For appropriate patient management timely identification of the tumour is critical. We evaluated the value of 18 F-FDG-PET/CT in the investigation of PNS. The case notes of 46 consecutive patients with clinically suspected PNS who underwent 18 F-FDG-PET/CT were reviewed retrospectively and the performance of PET/CT for detecting underlying tumours was assessed. PET/CT detected foci of increased 18 F-FDG uptake in 10 out of 46 patients. In six of these 10 patients combined PET/CT identified the underlying disease: four patients suffered from PNS; vasculitic and local metastatic disease was detected in two other patients. Based on our results, we believe that the role of positron emission tomography in the detection of occult neoplasms in patients with PNS has been overestimated in the past. In clinical practice, PNS is far more often suspected than proven. In our study combined PET/CT identified malignancy as the underlying cause of suspected PNS in only 8.7% (4/46). We believe that combined PET/CT should be reserved for stringently selected patients with a high clinical index of suspicion for PNS and after conventional imaging techniques fail to detect a tumour. (orig.)

  20. Impact of PET/CT image reconstruction methods and liver uptake normalization strategies on quantitative image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kuhnert, Georg; Sterzer, Sergej; Kahraman, Deniz; Dietlein, Markus; Drzezga, Alexander; Kobe, Carsten [University Hospital of Cologne, Department of Nuclear Medicine, Cologne (Germany); Boellaard, Ronald [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Scheffler, Matthias; Wolf, Juergen [University Hospital of Cologne, Lung Cancer Group Cologne, Department I of Internal Medicine, Center for Integrated Oncology Cologne Bonn, Cologne (Germany)

    2016-02-15

    In oncological imaging using PET/CT, the standardized uptake value has become the most common parameter used to measure tracer accumulation. The aim of this analysis was to evaluate ultra high definition (UHD) and ordered subset expectation maximization (OSEM) PET/CT reconstructions for their potential impact on quantification. We analyzed 40 PET/CT scans of lung cancer patients who had undergone PET/CT. Standardized uptake values corrected for body weight (SUV) and lean body mass (SUL) were determined in the single hottest lesion in the lung and normalized to the liver for UHD and OSEM reconstruction. Quantitative uptake values and their normalized ratios for the two reconstruction settings were compared using the Wilcoxon test. The distribution of quantitative uptake values and their ratios in relation to the reconstruction method used were demonstrated in the form of frequency distribution curves, box-plots and scatter plots. The agreement between OSEM and UHD reconstructions was assessed through Bland-Altman analysis. A significant difference was observed after OSEM and UHD reconstruction for SUV and SUL data tested (p < 0.0005 in all cases). The mean values of the ratios after OSEM and UHD reconstruction showed equally significant differences (p < 0.0005 in all cases). Bland-Altman analysis showed that the SUV and SUL and their normalized values were, on average, up to 60 % higher after UHD reconstruction as compared to OSEM reconstruction. OSEM and HD reconstruction brought a significant difference for SUV and SUL, which remained constantly high after normalization to the liver, indicating that standardization of reconstruction and the use of comparable SUV measurements are crucial when using PET/CT. (orig.)

  1. Perivascular epithelioid cell tumour: Dynamic CT, MRI and clinicopathological characteristics—Analysis of 32 cases and review of the literature

    International Nuclear Information System (INIS)

    Tan, Y.; Zhang, H.; Xiao, E.-H.

    2013-01-01

    Aim: To evaluate the dynamic computed tomography (CT), magnetic resonance imaging (MRI), and clinicopathological characteristics of perivascular epithelioid cell tumours (PEComas), thus improving the diagnosis of the tumour. Materials and methods: A retrospective analysis was undertaken of the dynamic CT, MRI, and clinicopathological characteristics of 32 PEComas diagnosed at histopathology during the period 1 January 2005 to 1 March 2012 at two hospitals. Results: The age of the patients ranged from 14–80 years (mean 43.3 years). There were more women in this group (19/32). Solitary tumours were identified in kidney (n = 16), liver (n = 7), gynaecological organs (n = 2), retroperitoneal soft tissue (n = 2), lung (n = 2), palate (n = 1), left groin (n = 1). One patient had multiple tumours in the liver, kidney, and retroperitoneal soft tissue. Dynamic CT (32 cases) and MRI (15 cases) demonstrated tumours that were of low density or hypointense on T1-weighted imaging (WI) and hyperintense on T2WI; some were isodense with fat (CT: 10/32; MRI: 6/15). The tumours usually had well-defined borders and were of a regular shape (CT: 26/32; MRI: 12/15). Tumour diameters ranged from 1.5–18 cm (mean 5.1 cm). Most tumours (CT: 21/32, MRI: 10/15) enhanced heterogeneously and significantly on arterial and venous phases. Tumours appeared slightly hypodense on delayed CT imaging, although some (6/32) had delayed enhancement. The expression rate of HMB-45 (human melanoma black monoclonal antibody) was 100% (32/32). Histological classification in 22 cases (22/32) was epithelioid angiomyolipoma (AML), three (3/32) were clear cell “sugar” tumours (CCSTs), two (2/32) were lymphangioleiomyomatosis (LAM), and two (2/32) were clear cell myomelanocytic tumours of the falciform ligament/ligamentum teres (CCMMT). Three tumours did not have a specific classification. Conclusion: Knowledge of dynamic CT, MRI, and clinicopathological characteristics could help improve the diagnosis of

  2. Histogram Analysis of CT Perfusion of Hepatocellular Carcinoma for Predicting Response to Transarterial Radioembolization: Value of Tumor Heterogeneity Assessment.

    Science.gov (United States)

    Reiner, Caecilia S; Gordic, Sonja; Puippe, Gilbert; Morsbach, Fabian; Wurnig, Moritz; Schaefer, Niklaus; Veit-Haibach, Patrick; Pfammatter, Thomas; Alkadhi, Hatem

    2016-03-01

    To evaluate in patients with hepatocellular carcinoma (HCC), whether assessment of tumor heterogeneity by histogram analysis of computed tomography (CT) perfusion helps predicting response to transarterial radioembolization (TARE). Sixteen patients (15 male; mean age 65 years; age range 47-80 years) with HCC underwent CT liver perfusion for treatment planning prior to TARE with Yttrium-90 microspheres. Arterial perfusion (AP) derived from CT perfusion was measured in the entire tumor volume, and heterogeneity was analyzed voxel-wise by histogram analysis. Response to TARE was evaluated on follow-up imaging (median follow-up, 129 days) based on modified Response Evaluation Criteria in Solid Tumors (mRECIST). Results of histogram analysis and mean AP values of the tumor were compared between responders and non-responders. Receiver operating characteristics were calculated to determine the parameters' ability to discriminate responders from non-responders. According to mRECIST, 8 patients (50%) were responders and 8 (50%) non-responders. Comparing responders and non-responders, the 50th and 75th percentile of AP derived from histogram analysis was significantly different [AP 43.8/54.3 vs. 27.6/34.3 mL min(-1) 100 mL(-1)); p 0.05) was not. Further heterogeneity parameters from histogram analysis (skewness, coefficient of variation, and 25th percentile) did not differ between responders and non-responders (p > 0.05). If the cut-off for the 75th percentile was set to an AP of 37.5 mL min(-1) 100 mL(-1), therapy response could be predicted with a sensitivity of 88% (7/8) and specificity of 75% (6/8). Voxel-wise histogram analysis of pretreatment CT perfusion indicating tumor heterogeneity of HCC improves the pretreatment prediction of response to TARE.

  3. Clinical Utility of Dual-Energy CT Analysis of Bone Marrow Edema in Acute Wrist Fractures.

    Science.gov (United States)

    Ali, Ismail T; Wong, William D; Liang, Teresa; Khosa, Faisal; Mian, Memoona; Jalal, Sabeena; Nicolaou, Savvas

    2018-04-01

    The purpose of this study is to determine the utility of dual-energy CT (DECT) for assessing carpal fractures and to obtain an attenuation value cutoff (in Hounsfield units) to identify bone marrow edema due to an acute carpal fracture. In this retrospective study, 24 patients who presented with wrist fractures from September 3, 2014, through March 9, 2015, underwent imaging with DECT (80 and 140 kVp). Using the three-material decomposition algorithm specific for virtual noncalcium to construct images, two radiologists identified carpal fractures and associated bone marrow edema. Readers noted the attenuation at areas with and without bone marrow edema. The cutoff value was obtained by ROC analysis and was internally validated on 13 separate patients with suspected wrist fractures. A p edema than in areas without it (p edema associated with acute wrist fractures with 100% sensitivity and 99.5% specificity, compared with visual DECT interpretation. In the 13 validation cases, the cutoff of 5.90 HU identified bone marrow edema with 100% accuracy, compared with visual interpretation. Kappa values were 0.83 between the two readings by reader 1, and 0.73 and 0.96 comparing the two readings of reader 1 with the reading by reader 2. DECT is a useful tool for identifying bone marrow edema in the setting of acute wrist fractures, providing an alternative to MRI. A cutoff value of 5.90 HU can be used for accurate diagnosis and exclusion of carpal fractures.

  4. Clinical aspects and prognosis of intraventricular hemorrhage with cerebrovascular disease. CT findings and etiological analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Yukio; Nakazawa, Shozo; Higuchi, Hiroshi; Ueda, Kenji; Kouzo, [Nippon Medical School, Tokyo

    1982-10-01

    Intraventricular hemorrhage with cerebrovascular disease was identified in 81 cases and death occurred within seven days in 34 cases. Hypertension was the most common etiological factor, accounting for 40 of the 81 cases. Cerebral aneurysm was the second most common cause accounting for 27 cases, arteriovenous malformation accounted for 9 of the cases, and 5 were of other causes. Signs of primary or secondary brain stem dysfunction were mainly seen in cases with hypertension and aneurysm, while cases with arteriovenous malformation had benign courses. The mortality depended on the severity of intraventricular hemorrhage; i.e., the distribution, site, and the number of cast formation. The presence of intraventricular clot in the third and/or fourth ventricles was correlated with a high mortality rate, especially in cases accompanied by cast formation and third and fourth ventricular dilatation, which affects hypothalamus and brain stem function. Analysis of CT findings for the mechanism of intraventricular hemorrhage revealed three types: extension type, in which massive intracerebral hematomas extended and ruptured into ventricles; the direct type, which bled directly into ventricles without forming definite intracerebral hematomas; and the reflux type, which was characterized by reflux of the subarachnoid blood.

  5. Automated segmentation of muscle and adipose tissue on CT images for human body composition analysis

    Science.gov (United States)

    Chung, Howard; Cobzas, Dana; Birdsell, Laura; Lieffers, Jessica; Baracos, Vickie

    2009-02-01

    The ability to compute body composition in cancer patients lends itself to determining the specific clinical outcomes associated with fat and lean tissue stores. For example, a wasting syndrome of advanced disease associates with shortened survival. Moreover, certain tissue compartments represent sites for drug distribution and are likely determinants of chemotherapy efficacy and toxicity. CT images are abundant, but these cannot be fully exploited unless there exist practical and fast approaches for tissue quantification. Here we propose a fully automated method for segmenting muscle, visceral and subcutaneous adipose tissues, taking the approach of shape modeling for the analysis of skeletal muscle. Muscle shape is represented using PCA encoded Free Form Deformations with respect to a mean shape. The shape model is learned from manually segmented images and used in conjunction with a tissue appearance prior. VAT and SAT are segmented based on the final deformed muscle shape. In comparing the automatic and manual methods, coefficients of variation (COV) (1 - 2%), were similar to or smaller than inter- and intra-observer COVs reported for manual segmentation.

  6. Sex determination of a Tunisian population by CT scan analysis of the skull.

    Science.gov (United States)

    Zaafrane, Malek; Ben Khelil, Mehdi; Naccache, Ines; Ezzedine, Ekbel; Savall, Frédéric; Telmon, Norbert; Mnif, Najla; Hamdoun, Moncef

    2018-05-01

    It is widely accepted that the estimation of biological attributes in the human skeleton is more accurate when population-specific standards are applied. With the shortage of such data for contemporary North African populations, it is duly required to establish population-specific standards. We present here the first craniometric standards for sex determination of a contemporary Tunisian population. The aim of this study was to analyze the correlation between sex and metric parameters of the skull in this population using CT scan analysis and to generate proper reliable standards for sex determination of a complete or fragmented skull. The study sample comprised cranial multislice computed tomography scans of 510 individuals equally distributed by sex. ASIR TM software in a General Electric TM workstation was used to position 37 landmarks along the volume-rendered images and the multiplanar slices, defining 27 inter-landmark distances. Frontal and parietal bone thickness was also measured for each case. The data were analyzed using basic descriptive statistics and logistic regression with cross-validation of classification results. All of the measurements were sexually dimorphic with male values being higher than female values. A nine-variable model achieved the maximum classification accuracy of 90% with -2.9% sex bias and a six-variable model yielded 85.9% sexing accuracy with -0.97% sex bias. We conclude that the skull is highly dimorphic and represents a reliable bone for sex determination in contemporary Tunisian individuals.

  7. CT finding of right retroperitoneal space : analysis of extension of right perirenal hematoma

    International Nuclear Information System (INIS)

    Seo, Kwang Won; Kim, Kyung Rak; Lee, Hyeok; Kim, Young Hwa; Cho, Won Soo; Kim, Il Young

    1997-01-01

    To understand the structure and character of the right retroperitoneal space by analysis of the extension of retroperitoneal hematoma in patients with traumatic right renal injuries. We retrospectively reviewed CT scans of 13 patients with right retroperitoneal hematomas caused by right renal injury. At te renal level, we analyzed the relation of a hematoma contacting psoas muscle with other retroperitoneal compartmental hematomas. At the suprarenal level, a perirenal hematoma and a hematoma contacting the diaphragm were analyzed according to their relation with intrahepatic IVC and pericaval hematoma. Below renal hilar level, all hematomas contacting psoas muscle, observed in eight cases, were connected with retrorenal extension of anterior pararenal hematoma. At the suprarenal level, intrahepatic pericaval hematomas were not, in all 13 cases, connected with a hematoma contacting the diaphragm, but with a perirenal hematoma. At the upper suprarenal level, the only pericaval hematomas containing a medial component of perirenal hematoma extended superiorly to the upper one third of the tenth thoracic vertebral body. The anterior renal fascia envelops perirenal space except in its medial aspect. In the upper suprarenal region, the anterior and posterior planes of the anterior renal fascia unite to fuse with diaphragmatic fascia, but along the medial aspect they fuse with intrahepatic pericaval connective tissue and posteromedial diaphragm, respectively

  8. Proteome Analysis of Disease Resistance against Ralstonia solanacearum in Potato Cultivar CT206-10

    Directory of Open Access Journals (Sweden)

    Sangryeol Park

    2016-02-01

    Full Text Available Potato is one of the most important crops worldwide. Its commercial cultivars are highly susceptible to many fungal and bacterial diseases. Among these, bacterial wilt caused by Ralstonia solanacearum causes significant yield loss. In the present study, integrated proteomics and genomics approaches were used in order to identify bacterial wilt resistant genes from Rs resistance potato cultivar CT-206-10. 2-DE and MALDI-TOF/TOF-MS analysis identified eight differentially abundant proteins including glycine-rich RNA binding protein (GRP, tomato stress induced-1 (TSI-1 protein, pathogenesis-related (STH-2 protein and pentatricopeptide repeat containing (PPR protein in response to Rs infection. Further, semi-quantitative RT-PCR identified up-regulation in transcript levels of all these genes upon Rs infection. Taken together, our results showed the involvement of the identified proteins in the Rs stress tolerance in potato. In the future, it would be interesting to raise the transgenic plants to further validate their involvement in resistance against Rs in potato.

  9. MicroCT Analysis of Micro-Nano Titanium Implant Surface on the Osseointegration.

    Science.gov (United States)

    Ban, Jaesam; Kang, Seongsoo; Kim, Jihyun; Lee, Kwangmin; Hyunpil, Lim; Vang, Mongsook; Yang, Hongso; Oh, Gyejeong; Kim, Hyunseung; Hwang, Gabwoon; Jung, Yongho; Lee, Kyungku; Park, Sangwon; Yunl, Kwidug

    2015-01-01

    This study was to investigate the effects of micro-nano titanium implant surface on the osseointegration. A total of 36 screw-shaped implants were used. The implant surfaces were classified into 3 groups (n = 12): machined surface (M group), nanosurface which is nanotube formation on the machined surface (MA group) and nano-micro surface which is nanotube formation on the RBM surface (RA group). Anodic oxidation was performed at a 20 V for 10 min with 1 M H3PO4 and 1.5 wt% HF solutions. The implants were installed on the humerus on 6 beagles. After 4 and 12 weeks, the morphometric analysis with micro CT (skyscan 1172, SKYSCAN, Antwerpen, Belgium) was done. The data were statistically analyzed with two-way ANOVA. Bone mineral density and bone volume were significantly increased depending on time. RA group showed the highest bone mineral density and bone volume at 4 weeks and 12 weeks significantly. It indicated that nano-micro titanium implant surface showed faster and more mature osseointegration.

  10. CT14 intrinsic charm parton distribution functions from CTEQ-TEA global analysis

    Science.gov (United States)

    Hou, Tie-Jiun; Dulat, Sayipjamal; Gao, Jun; Guzzi, Marco; Huston, Joey; Nadolsky, Pavel; Schmidt, Carl; Winter, Jan; Xie, Keping; Yuan, C.-P.

    2018-02-01

    We investigate the possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon, theoretical issues arising in its interpretation, and its potential impact on LHC scattering processes. The "fitted charm" PDF obtained in various QCD analyses contains a process-dependent component that is partly traced to power-suppressed radiative contributions in DIS and is generally different at the LHC. We discuss separation of the universal component of the nonperturbative charm from the rest of the radiative contributions and estimate its magnitude in the CT14 global QCD analysis at the next-to-next-to leading order in the QCD coupling strength, including the latest experimental data from HERA and the Large Hadron Collider. Models for the nonperturbative charm PDF are examined as a function of the charm quark mass and other parameters. The prospects for testing these models in the associated production of a Z boson and a charm jet at the LHC are studied under realistic assumptions, including effects of the final-state parton showering.

  11. Analysis of the truth loading conditions of a austenitic CT specimen during a SCC experiment

    International Nuclear Information System (INIS)

    Marie, S.; Guerre, C.; Herms, E.

    2012-01-01

    With the aim to investigate the influence of strain hardening on the stainless steels susceptibility to stress corrosion cracking, tests were conducted in PWR environment on CT specimens, taken from a 316L stainless steel sheet cold rolled to 40% in thickness reduction. The initial cracks obtained by the fatigue pre-cracking have an atypical 'V' shape with smaller propagation in the center of the CT thickness compared to nominal propagation observed at both sides. The initial explanation was to consider a stress intensity factor derived from classical reference solution on the basis of a straight crack front, and considering the local value of the crack depth in the equation. This assumption raised several problems analyses in this paper. This particular shape of the initial defect may be related to several factors, and partly to the 40% cold rolling. It is likely that the hardening is not uniform, with a higher rate at the specimen sides than in the central area. In addition, significant residual stresses due to the gradient of mechanical properties are observed. Due to the high rate of work hardening by rolling of the sheet metal, a gradient of the mechanical properties through the thickness was determined, and the residual stresses profile induced by this process was measured. The variations obtained are consistent with each other: the material is more hardened in the vicinity of specimen surface and residual stresses are compressive in nature in the central part of the specimen and of tensile type on the flanks. All these data were firstly considered in order to assess their role regarding the particular form of the initial crack front obtained after fatigue: the 3D finite element calculations taking into account the true shape of the crack front demonstrate the relationship between the characteristics of the experimental crack front obtained after fatigue pre-cracking and the residual stresses. Moreover, from the residual stresses measured on the plate where

  12. Propagation of aortic dissection and visceral artery compromise. Three-dimensional analysis on CT angiography

    International Nuclear Information System (INIS)

    Minamiguchi, Hiroki

    2003-01-01

    artery were significant factors to explain the difference. Three-dimensional analysis using CT angiography was essential to understand the propagation of aortic dissection and visceral artery compromise. (author)

  13. CT study of infantile cerebral vitamin B1 deficiency (analysis of 22 cases)

    International Nuclear Information System (INIS)

    Liu Bin; Xi Meifang; Wang Mengding; Wang Chaoxiu

    1998-01-01

    Purpose: To study the CT features of infantile cerebral vitamin B 1 deficiency. Methods: The authors retrospectively reviewed the clinical manifestations and CT findings of 22 cases of infantile vitamin B 1 deficiency. Results: The main clinical signs were seizure malaise dullness and vomiting. CT scans showed bilateral symmetrical hypodense foci in lenticular nucleus (20/22), head of caudate nucleus (15/22), thalamus (3/22), anterior limb of internal capsule (4/22), external capsule (1/22) and para-ventricle white matter (2/22), and in many cases, signs of cerebral atrophy. 22 cases received thiamine treatment and were fully recovered. Conclusion: The authors concluded that bilateral symmetric hypodense foci in lenticular nucleus thalamus, head of caudate nucleus, anterior limb of internal capsule, external capsule and para-ventricle white matter were important CT signs suggestive of infantile cerebral vitamin B 1 deficiency

  14. Analysis of the manifestation and feature of adrenal tumor on CT in 30 cases

    International Nuclear Information System (INIS)

    Xi Riquan; Xie Daohai; Guo Liang; Hu Chunhong; Fu Yingdi

    2001-01-01

    Objective: To analyze the manifestation and the feature of adrenal tumor with CT. Methods: The findings of various adrenal tumors with CT in 30 cases were analyzed retrospectively, the key to the diagnosis and differential diagnosis was suggested. Results: Usually, fibroxanthoma is inhomogeneous in density and moderate in size and was enhanced slightly after contrast medium administration. Pheochromocytoma is always larger and inhomogeneous in density and was enhanced markedly. The CT unit of myelo-lipoma simulated those of fluid or fat. Adrenal cyst has a low CT value and it showed cystic wall calcification. Aldosteronism adenoma was low in density and small in size, while cortisol adenoma was moderate in density and medium in size. Adrenocortical adenocarcinoma was the larger one with irregular margin and irregular hypodense areas inside. Metastatic carcinoma was larger and inhomogeneous in density. Conclusion: It is possible to increase the diagnostic rate by analysing the imaging feature of adrenal tumor

  15. The dream of a one-stop-shop : Meta-analysis on myocardial perfusion CT

    NARCIS (Netherlands)

    Pelgrim, Gert Jan; Dorrius, Monique; Xie, Xueqian; den Dekker, Martijn A. M.; Schoepf, U. Joseph; Henzler, Thomas; Oudkerk, Matthijs; Vliegenthart, Rozemarijn

    2015-01-01

    Purpose: To determine the diagnostic performance of computed tomography (CT) perfusion techniques for the detection of functionally relevant coronary artery disease (CAD) in comparison to reference standards, including invasive coronary angiography (ICA), single photon emission computed tomography

  16. Detailed statistical analysis plan for the Danish Palliative Care Trial (DanPaCT)

    DEFF Research Database (Denmark)

    Johnsen, Anna Thit; Petersen, Morten Aagaard; Gluud, Christian

    2014-01-01

    BACKGROUND: Advanced cancer patients experience considerable symptoms, problems, and needs. Early referral of these patients to specialized palliative care (SPC) could offer improvements. The Danish Palliative Care Trial (DanPaCT) investigates whether patients with metastatic cancer will benefit...

  17. Analysis of lenses absorbed dose in head CT scan with the use of bismuth shielding

    Energy Technology Data Exchange (ETDEWEB)

    Santos, F.S.; Santana, P.C., E-mail: fernanda.stephaniebh@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil); Mourão, A.P. [Centro de Educação Tecnológica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Computed Tomography (CT) has become an important tool to diagnose cancer and to obtain additional information for different clinical questions. However, CT scan usually requires a higher radiation exposure than a conventional radiography examination. Head CT scans are used for diagnosis of traumatic head injuries, infections and other diseases with instability. Based on this information, it was studied the dose variation deposited in the lenses and in nearby organs, such as: pharynx, hypophysis and salivary gland with and without the use of bismuth shield. In this study a head CT scan was performed on anthropomorphic male phantom using a GE scanner. Dose measurements have been performed by using radiochromic film strips to register the individual doses in the organs of interest. The results show that the lenses had a reduction of 26% of the dose with the use of the bismuth shield. (author)

  18. Clinical analysis of CT features in 200 neonates with hypoxic-ischemic encephalopathy (HIE)

    International Nuclear Information System (INIS)

    Zhang Fan

    2003-01-01

    Objective: To analyze the CT features of HIE in neonates. Methods: CT scanning was performed in 200 neonates with HIE. Results: The CT features in 200 HIE were hypo-attenuated substantia alba, accompanied with intra-cranial hemorrhage, widened cavity of septum pellucidum and cerebral infarction. In total 200 cases, mild HIE was found in 118 cases, moderate HIE was revealed in 67 cases and severe condition was observed in 15 cases. Intra-cranial hemorrhage was noted in 87 cases. Conclusion: The cerebral injury should be diagnosed by the findings of hypo-attenuated substantia alba and intracranial hemorrhage on CT scan, combined with clinical histories and manifestations of intro-uterine neonate asphyxia

  19. Analysis the findings of chest radiograph and CT scan in 217 acute thoracic trauma

    International Nuclear Information System (INIS)

    Huang Shaoying

    2005-01-01

    Objective: To evaluate chest radiograph and CT scan in assessing acute thoracic trauma. Methods: Retrospectively analyzed the findings of chest radiograph and CT scan in 217 cases of acute thoracic trauma and positive rate of each modality was compared. Results: The positive rate of rib and clavicle fracture was higher in chest radiograph than these in CT scan. But the positive rate of chest wall hematoma, mediastinum and subcutaneous emphysema, pneumothorax, hydropneumothorax, damage of lung parenchyma and traumatic pulmonary atelectasis was higher in CT scan than those in chest radiograph. Conclusion: The application of the combined imaging modalities improves assessing of acute thoracic trauma, because the imaging manifestation of the lesion is various. (authors)

  20. Analysis of the sacrum: CT with two-dimensional and three-dimensional imaging

    International Nuclear Information System (INIS)

    Magid, D.; Fishman, E.K.; Scott, W.W. Jr.; Brooker, A.F. Jr.

    1987-01-01

    Fifteen patients with sacral lesions were assessed using CT and volumetric 3D image rendering. Lesions imaged included sacral fractures, tumors, osteomyelitis, dysplasia, and sacroiliac diastasis. In all cases, transaxial CT alone was superior to conventional radiographs, and CT with 3D was more clinically useful than CT alone. The 3D real-time video format allows rotation and manipulation in several planes, including the X (spinal) and Z (somersaulting) axes, for optimal visualization of abnormalities. The Z axis gives unique unimpeded inlet, outlet, and ''bird's-eye'' views of the pelvis and sacrum, enhancing detection and characterization of sacral of SI disruptions and subsequent pelvic ring compromise. Because of the ease of assimilating information in such a format, 3D may become the key modality for preoperative planning and for postoperative follow-up

  1. Acquired cystic kidney disease in dialysis and renal transplant patients: ultrasonography and CT analysis

    International Nuclear Information System (INIS)

    Jeon, Young Tae; Lee, Hae Kyung; Jung, Mi Sun; Yoon, Jong Pil; Hong, Hyun Sook; Kwon, Kui Hyang; Choi, Deuk Lin; Hwang, Seung Duk; Lee, Hi Bahl

    1997-01-01

    To evaluate by US and CT the incidence and complications of acquired cystic kidney disease (ACKD) in dialysis and renal transplant patients and to compare the effectiveness of US and CT in the diagnosis of this entity. This study was prospectively performed in 70 dialysis patients and 13 renal transplant patients, and excluded any with multiple renal cysts or polycystic kidney disease, on as seen on initial films. US were obtained in all patients, and CT scans were randomly obtained in 27 who had been on dialysis for 3 years or more; all these US and CT scans were analyzed, with particular emphasis on whether or not cysts were present. In order to correlate the numbers of cysts with duration of dialysis, all patients were assigned to one of three groups, according to the number of cysts found (group 1, 0; group 2, 1-4; group 3, >4). Only group 3 was diagnosed as suffering from ACKD. In order to compare the cyst-detection capability of US with that of CT, 27 dialysis patients who had undergone US and CT were divided into four groups according to the number of cysts found (grade 1, 0; grade 2, 1-4; grade 3, 5-10; grade 4, >10). Seventy dialysis patients were divided according to the results of US, as follows : group 1, 20%; group 2, 47.1%; group 3, 32.9%. The mean duration of dialysis in group 1 (31.9 months) was statistically different from that in group 2 (50.6 months) and in group 3 (95.8 months) (p < 0.000). Thirteen renal transplant patients were divided as follows : group 1, 61.5%; group 2, 38.5%; group 3, 0%. In dialysis patients with ACKD, complications noted were renal cell carcinoma (n=1), hemorrhagic cysts (n=2), and hematomas (n=2). Among the 27 dialysis patients who underwent CT, this and US showed an equal grade of cystic change in 53.7%, while CT showed a higher grade in 46.3%. The detection rate of ACKD in these 27 patients was 46% on US and 63% on CT. A prolongation of dialysis corresponded to an increased incidence of ACKD; renal neoplasm and

  2. Monitoring and analysis PET/CT workplace radioactivity level in Shanghai

    International Nuclear Information System (INIS)

    Wang Bin; Gao Linfeng; Qian Aijun; Yao Jie; Shen Jinfu; Ji Guiyi

    2012-01-01

    Objective: To understand the PET/CT basic information in Shanghai, through monitoring radioactivity level of PET/CT workplace, to get the radiological protection information about PET/CT place. Methods: Through the γ radiation air absorbed dose rate and the β surface contamination to investigate PET/CT medical institutions in Shanghai. Results: By the end of 2011, there were 13 sets of PET/CT. Detecting show that γ radiation air absorbed dose rate is at relatively higher level in waiting room and the injection rooms, the date of waiting room door was up to 19552 nSv/h, the maximum value of injection room desk surface was 6136 nSv/h, the middle of injection room was up to 5408 nSv/h. Any date was certain the limits of national standard of β surface contamination, the middle of in the injection room. It is still higher on the window and wastes barrel. Conclusion: The radiation protection of PET/CT workplace is proper, surface contamination levels can be controlled within in the standard limits, but there are a blank of limits about nuclear medicine place of γ radiation absorbed dose rate air in the national standard, and external exposure protection is still the key of radiation protection. (authors)

  3. CT imaging of hepatic veno-occlusive disease (an analysis 14 cases)

    International Nuclear Information System (INIS)

    Zhang Guohua; Kong Azhao; Fang Junwei; Chen Yuejing; Zheng Weiliang; Dong Danjun; Zhang Shizheng

    2006-01-01

    Objective: To probe imaging characteristics of the hepatic veno-occlusive disease (VOD) based on clinical features and abdomen CT findings. Methods: Fourteen patients including 6 male and 8 female aged from 41 to 73 years were enrolled in this study. They all had previous trauma history and notoginseng was given as herbal remedy. Dynamic enhanced CT and color Dopplor ultrasound examinations were routinely used. Two of them received venous angiography and four cases were pathologically proved as VOD after CT guided needle biopsy. Results: Hepatic swelling and ascites were found on plain CT scan. Diffuse patchy areas without enhancement indicative of poorly hepatic perfusion were found. Hepatic veins were compressed and became thin, and inferior vena cava was flat and narrow without distal dilation or collateral circulation. No obstruction of hepatic veins and inferior vena cava was found on ultrasound and venography. Conclusion: Dynamic enhanced CT is highly valuable for early assessing VOD and imaging features of venous hepatic congestion found on CT was strongly suggestive of VOD if there's previous history of treatment of gynura segetum. (authors)

  4. Pancreatic lipoma: An incydentaloma which can resemble cancer – analysis of 13 cases studied with CT and MRI

    International Nuclear Information System (INIS)

    Stadnik, Anna; Cieszanowski, Andrzej; Bakoń, Leopold; Grodzicka, Agnieszka; Rowiński, Olgierd

    2012-01-01

    The purpose of this article is to present computed tomography (CT) and magnetic resonance imaging (MRI) findings of rare pancreatic lipomas. The analysis covered 13 patients (7 men and 6 women, aged 47–88, average: 65.6 years), with 13 pancreatic lipomas, whose cases constituted the basis for 10 contrast-enhanced CT and 5 MRI studies. Lipomas measured from 6 mm to 32 mm (average 12.8 mm) and were located in the pancreatic head (n=7), body (n=2), tail (n=3) and uncinate process (n=1). Most lesions (n=11) were homogenous, well-circumscribed. On contrast-enhanced CT scans, macroscopic fat (<−30 HU) was present in 9 lipomas. In one case (10 mm lesion) the density was −20 HU and the lesion was poorly circumscribed with septations, which altogether made it difficult to precisely characterize its contents. On MR scans fat was demonstrated in all studied cases (n=5). Lipomas are rare, small, homogenous and well-circumscribed pancreatic tumours. The most important feature, decisive for the diagnosis and distinguishing them from pancreatic carcinoma, is detection of fatty tissue on CT and MR scans. In these cases differential diagnosis includes other rare fatty tumours of the pancreas (focal fatty infiltration, teratoma, liposarcoma)

  5. A study on a comparative analysis of 2D and 3D planning using CT simulator for transbronchial brachytherapy

    International Nuclear Information System (INIS)

    Seo, Dong Rin; Kim, Dae Sup; Back, Geum Mun

    2013-01-01

    Transbronchial brachytherapy used in the two-dimensional treatment planning difficult to identify the location of the tumor in the affected area to determine the process analysis. In this study, we have done a comparative analysis for the patient's treatment planning using a CT simulator. The analysis was performed by the patients who visited the hospital to June 2012. The patient carried out CT-image by CT simulator, and we were plan to compare with a two-dimensional and three dimensional treatment planning using a Oncentra Brachy planning system (Nucletron, Netherlands). The location of the catheter was confirmed the each time on a treatment planning for fractionated transbronchial brachytherapy. GTV volumes were 3.5 cm 3 and 3.3 cm 3 . Also easy to determine the dose distribution of the tumor, the errors of a dose delivery were confirmed dose distribution of the prescribed dose for GTV. In the first treatment was 92% and the second was 88%. In order to compensate for the problem through a two-dimensional treatment planning, it is necessary to be tested process for the accurate identification and analysis of the treatment volume and dose distribution. Quantitatively determine the dose delivery error process that is reflected to the treatment planning is required

  6. A study on a comparative analysis of 2D and 3D planning using CT simulator for transbronchial brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong Rin; Kim, Dae Sup; Back, Geum Mun [Dept. of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of)

    2013-03-15

    Transbronchial brachytherapy used in the two-dimensional treatment planning difficult to identify the location of the tumor in the affected area to determine the process analysis. In this study, we have done a comparative analysis for the patient's treatment planning using a CT simulator. The analysis was performed by the patients who visited the hospital to June 2012. The patient carried out CT-image by CT simulator, and we were plan to compare with a two-dimensional and three dimensional treatment planning using a Oncentra Brachy planning system (Nucletron, Netherlands). The location of the catheter was confirmed the each time on a treatment planning for fractionated transbronchial brachytherapy. GTV volumes were 3.5 cm{sup 3} and 3.3 cm{sup 3}. Also easy to determine the dose distribution of the tumor, the errors of a dose delivery were confirmed dose distribution of the prescribed dose for GTV. In the first treatment was 92% and the second was 88%. In order to compensate for the problem through a two-dimensional treatment planning, it is necessary to be tested process for the accurate identification and analysis of the treatment volume and dose distribution. Quantitatively determine the dose delivery error process that is reflected to the treatment planning is required.

  7. Trends in CT colonography: bibliometric analysis of the 100 most-cited articles.

    Science.gov (United States)

    Mohammed, Mohammed Fahim; Chahal, Tejbir; Gong, Bo; Bhulani, Nizar; O'Keefe, Michael; O'Connell, Timothy; Nicolaou, Savvas; Khosa, Faisal

    2017-12-01

    Our purpose was to identify the top 100 cited articles, which focused on CT colonography (CTC). This list could then be analysed to establish trends in CTC research while also identifying common characteristics of highly cited works. Web of Science search was used to create a database of scientific journals using our search terms. A total of 10,597 articles were returned from this search. Articles were included if they focused on diagnostic imaging, imaging technique, cost-effectiveness analysis, clinical use, patient preference or trends in CTC. Articles were ranked by citation count and screened by two attending radiologists. The following information was collected from each article: database citations, citations per year, year published, journal, authors, department affiliation, study type and design, statistical analysis, sample size, modality and topic. Citations for the top 100 articles ranged from 73 to 1179, and citations per year ranged from 4.5 to 84.21. Articles were published across 22 journals, most commonly Radiology (n = 37) and American Journal of Roentgenology (n = 19). Authors contributed from 1 to 20 articles. 19% of first authors were affiliated with a department other than radiology. Of the 100 articles, the most common topics were imaging technique (n = 40), diagnostic utility of imaging (n = 28) and clinical uses (n = 18). Our study provides intellectual milestones in CTC research, reflecting on the characteristics and quality of published literature. This work also provides the most influential references related to CTC and serves as a guide to the features of a citable paper in this field.

  8. Integrated analysis of dynamic FET PET/CT parameters, histology, and methylation profiling of 44 gliomas.

    Science.gov (United States)

    Röhrich, Manuel; Huang, Kristin; Schrimpf, Daniel; Albert, Nathalie L; Hielscher, Thomas; von Deimling, Andreas; Schüller, Ulrich; Dimitrakopoulou-Strauss, Antonia; Haberkorn, Uwe

    2018-05-07

    Dynamic 18 F-FET PET/CT is a powerful tool for the diagnosis of gliomas. 18 F-FET PET time-activity curves (TAC) allow differentiation between histological low-grade gliomas (LGG) and high-grade gliomas (HGG). Molecular methods such as epigenetic profiling are of rising importance for glioma grading and subclassification. Here, we analysed dynamic 18 F-FET PET data, and the histological and epigenetic features of 44 gliomas. Dynamic 18 F-FET PET was performed in 44 patients with newly diagnosed, untreated glioma: 10 WHO grade II glioma, 13 WHO grade III glioma and 21 glioblastoma (GBM). All patients underwent stereotactic biopsy or tumour resection after 18 F-FET PET imaging. As well as histological analysis of tissue samples, DNA was subjected to epigenetic analysis using the Illumina 850 K methylation array. TACs, standardized uptake values corrected for background uptake in healthy tissue (SUVmax/BG), time to peak (TTP) and kinetic modelling parameters were correlated with histological diagnoses and with epigenetic signatures. Multivariate analyses were performed to evaluate the diagnostic accuracy of 18 F-FET PET in relation to the tumour groups identified by histological and methylation-based analysis. Epigenetic profiling led to substantial tumour reclassification, with six grade II/III gliomas reclassified as GBM. Overlap of HGG-typical TACs and LGG-typical TACs was dramatically reduced when tumours were clustered on the basis of their methylation profile. SUVmax/BG values of GBM were higher than those of LGGs following both histological diagnosis and methylation-based diagnosis. The differences in TTP between GBMs and grade II/III gliomas were greater following methylation-based diagnosis than following histological diagnosis. Kinetic modeling showed that relative K1 and fractal dimension (FD) values significantly differed in histology- and methylation-based GBM and grade II/III glioma between those diagnosed histologically and those diagnosed by

  9. Three-dimensional motion analysis of an improved head immobilization system for simulation, CT, MRI, and PET imaging

    International Nuclear Information System (INIS)

    Thornton, A.F. Jr.; Ten Haken, R.K.; Gerhardsson, A.; Correll, M.

    1991-01-01

    A mask/marker immobilization system for the routine radiation therapy treatment of head and neck disease is described, utilizing a commercially available thermoplastic mesh, indexed and mounted for a rigid frame attached to the therapy couch. Designed to permit CT, MRI, and PET diagnostics scans of the patient to be performed in the simulation and treatment position employing the same mask, the system has been tested in order to demonstrate the reproducibility of immobilization throughout a radical course of irradiation. Three-dimensional analysis of patient position over an 8-week course of daily radiation treatment has been performed for 9 patients from digitization of anatomic points identified on orthogonal radiographs. Studies employing weekly constructed system permits rapid mask formation to be performed on the treatment simulator, resulting in an immobilization device comparable to masks produced with vacuum-forming techniques. Details of motion analysis and central axis CT, MRI, and PET markers are offered. (author). 16 refs.; 3 figs

  10. Experimental investigation on the fracture behaviour of black shale by acoustic emission monitoring and CT image analysis during uniaxial compression

    Science.gov (United States)

    Wang, Y.; Li, C. H.; Hu, Y. Z.

    2018-04-01

    Plenty of mechanical experiments have been done to investigate the deformation and failure characteristics of shale; however, the anisotropic failure mechanism has not been well studied. Here, laboratory Uniaxial Compressive Strength tests on cylindrical shale samples obtained by drilling at different inclinations to bedding plane were performed. The failure behaviours of the shale samples were studied by real-time acoustic emission (AE) monitoring and post-test X-ray computer tomography (CT) analysis. The experimental results suggest that the pronounced bedding planes of shale have a great influence on the mechanical properties and AE patterns. The AE counts and AE cumulative energy release curves clearly demonstrate different morphology, and the `U'-shaped curve relationship between the AE counts, AE cumulative energy release and bedding inclination was first documented. The post-test CT image analysis shows the crack patterns via 2-D image reconstructions, an index of stimulated fracture density is defined to represent the anisotropic failure mode of shale. What is more, the most striking finding is that the AE monitoring results are in good agreement with the CT analysis. The structural difference in the shale sample is the controlling factor resulting in the anisotropy of AE patterns. The pronounced bedding structure in the shale formation results in an anisotropy of elasticity, strength and AE information from which the changes in strength dominate the entire failure pattern of the shale samples.

  11. Breakeven analysis of computed tomography (Based on utilization of whole body C.T. scanner of SNU hospital)

    International Nuclear Information System (INIS)

    Cheung, Hwan; Choi, Myung Jun; Yoo, Chang Ho

    1986-01-01

    The C.T. scanner, an important tool for image-based diagnostics, is one of the costliest types of medical equipment. At present, there are in Korea a total of 66 units installed, and more units will be added in the future. For the fact the price of the C.T. scanner as well as scanning charge for using the equipment is very high as compared to those of the other kinds of medical equipment. The break-even analysis of computed tomography is considered fundamental as well as essential both to rational hospital management and keeping the charge for its use at an optimum level in consideration of the patient's medical expense burden. Even if pursuit of profits is not the role objective of a hospital, it cannot be denied that a break-even analysis provides an important factor for the decision making process in hospital management. The present study has the purpose of finding the ways and means to help rationalize hospital operation and improve its earning power through break-even analysis of C.T. scanner operation. For this purpose the total cost of the GE 8800 Whole Body C. T. Scanner installed at the Seoul National University Hospital was computed, and the records of its operation were analyzed. The expenses for its operation were divided into direct and indirect expenses depending on whether generation of the cost was recognized in the C. T. room or not, and the actual cost was computed for each of these accounting units

  12. A COMPARATIVE ANALYSIS OF THE SUPERNOVA LEGACY SURVEY SAMPLE WITH ΛCDM AND THE Rh=ct UNIVERSE

    International Nuclear Information System (INIS)

    Wei, Jun-Jie; Wu, Xue-Feng; Melia, Fulvio; Maier, Robert S.

    2015-01-01

    The use of Type Ia supernovae (SNe Ia) has thus far produced the most reliable measurement of the expansion history of the universe, suggesting that ΛCDM offers the best explanation for the redshift–luminosity distribution observed in these events. However, analysis of other kinds of sources, such as cosmic chronometers, gamma-ray bursts, and high-z quasars, conflicts with this conclusion, indicating instead that the constant expansion rate implied by the R h = ct universe is a better fit to the data. The central difficulty with the use of SNe Ia as standard candles is that one must optimize three or four nuisance parameters characterizing supernova (SN) luminosities simultaneously with the parameters of an expansion model. Hence, in comparing competing models, one must reduce the data independently for each. We carry out such a comparison of ΛCDM and the R h = ct universe using the SN Legacy Survey sample of 252 SN events, and show that each model fits its individually reduced data very well. However, since R h = ct has only one free parameter (the Hubble constant), it follows from a standard model selection technique that it is to be preferred over ΛCDM, the minimalist version of which has three (the Hubble constant, the scaled matter density, and either the spatial curvature constant or the dark energy equation-of-state parameter). We estimate using the Bayes Information Criterion that in a pairwise comparison, the likelihood of R h = ct is ∼90%, compared with only ∼10% for a minimalist form of ΛCDM, in which dark energy is simply a cosmological constant. Compared to R h = ct, versions of the standard model with more elaborate parametrizations of dark energy are judged to be even less likely

  13. 18F-FDG-PET/CT parameters as imaging biomarkers in oral cavity squamous cell carcinoma, is visual analysis of PET and contrast enhanced CT better than the numbers?

    Energy Technology Data Exchange (ETDEWEB)

    Kendi, A.Tuba, E-mail: ayse.kendi@emory.edu [Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA (United States); Corey, Amanda [Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA (United States); Magliocca, Kelly R. [Department of Pathology, Emory University, Atlanta, GA (United States); Nickleach, Dana C. [Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute of Emory University, Atlanta, GA (United States); Galt, James [Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA (United States); Switchenko, Jeffrey M. [Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute of Emory University, Atlanta, GA (United States); El-Deiry, Mark W.; Wadsworth, J. Trad [Otolaryngology Head and Neck Surgery, Emory University, Atlanta, GA (United States); Hudgins, Patricia A. [Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA (United States); Saba, Nabil F. [Hematology Oncology, Winship Cancer Institute of Emory University, Atlanta, GA (United States); Schuster, David M. [Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA (United States)

    2015-06-15

    multivariable analysis, patients with high (≥ median) tumor SUV max (OR 6.3), SUV mean (OR 6.3), MTV (OR 19.0), TLG (OR 19.0), SAM (OR 11.7) and N SAM (OR 19.0) had high pathological T-stage (T3/T4) (p < 0.05). Ring/heterogeneous pattern on CECT qualitative assessment was associated with worse DMFS and OS. Conclusion: High PET/CT parameters were associated with pathologically advanced T stage (T3/T4). Qualitative assessment of CECT has prognostic value. PET/CT parameters did not predict clinical outcome.

  14. 18F-FDG-PET/CT parameters as imaging biomarkers in oral cavity squamous cell carcinoma, is visual analysis of PET and contrast enhanced CT better than the numbers?

    International Nuclear Information System (INIS)

    Kendi, A.Tuba; Corey, Amanda; Magliocca, Kelly R.; Nickleach, Dana C.; Galt, James; Switchenko, Jeffrey M.; El-Deiry, Mark W.; Wadsworth, J. Trad; Hudgins, Patricia A.; Saba, Nabil F.; Schuster, David M.

    2015-01-01

    multivariable analysis, patients with high (≥ median) tumor SUV max (OR 6.3), SUV mean (OR 6.3), MTV (OR 19.0), TLG (OR 19.0), SAM (OR 11.7) and N SAM (OR 19.0) had high pathological T-stage (T3/T4) (p < 0.05). Ring/heterogeneous pattern on CECT qualitative assessment was associated with worse DMFS and OS. Conclusion: High PET/CT parameters were associated with pathologically advanced T stage (T3/T4). Qualitative assessment of CECT has prognostic value. PET/CT parameters did not predict clinical outcome

  15. CT diagnosis for thyroglossal duct cyst of infants: analysis of 23 cases

    International Nuclear Information System (INIS)

    Shao Jianbo; Yang Minjie; Xu Zugao; Shen Jiefeng; Zhong Muxiang

    2001-01-01

    Objective: To investigate the CT features of thyroglossal duct cyst (TDC) in infants. Methods: CT, surgical and pathological findings in 23 infants (the age ranged from 1 month to 3 years; mean age 2.2 years) with TDC were reviewed. The size, shape, and site of the cysts, the relationship of the cyst to ossa hyoideum and thyroid gland, the density definition margins, and enhancement of cyst were evaluated. Results: In CT features, 18 of the 23 cases were located at midline of the neck and the other 5 cases deviated aside. 6 of 23 cases were directly related to the ossa hyoideum and 17 of 23 cases were directly related to thyroid gland. All TDC appeared as a round or ovary shape with saccular low density (15 cases) or iso-attenuating mass(8 cases). No enhancement was detected within the cysts after intravenous contrast media administration in 14 cases, but enhancement of the wall was present in 11 cases (11/14). Calcification, fistula, or intralaryngeal extension of TDC were not found. Conclusion: TDC in infants was typically a non-enhanced homogeneous low-attenuating cyst with enhancement of the cyst wall on CT, and TDC can be diagnosed correctly by CT

  16. Image analysis of the inner ear with CT and MR imaging

    International Nuclear Information System (INIS)

    Kumakawa, Kohzoh; Takeda, Hidehiko; Mutoh, Naoko; Miyakawa, Kohichi; Yukawa, Kumiko; Funasaka, Sohtaro.

    1992-01-01

    Recent progress in magnetic resonance imaging (MRI) has made it possible to obtain detailed images of the inner ear by delineating the lymphatic fluid within the labyrinth. We analyzed CT scans and MR imaging in 70 ears manifesting profound deafness owing to inner ear lesions and compared their detective ability for inner ear lesions. The following results were obtained. CT scan examination showed slight to extensive ossification of the labyrinth in six ears (9%), whereas MRI examination revealed low to absent signal intensity of the inner ear in nine ears (13%). Therefore, it was concluded that MRI is more sensitive in detecting abnormalities of the inner ear than CT scan. MRI provided useful information as to whether the cochlear turn is filled with lymphatic fluid or obstructed. This point was one of the greatest advantages of MRI over CT scan. Abnormal findings in either or both the CT scan and the MRI were detected in suppurative labyrinthitis occurring secondary to chronic otitis media, bacterial meningitis and in inner ear trauma. However, such abnormal findings were not detected in patients with idiopathic progressive sensorineural hearing loss, ototoxity or sudden deafness. These findings should be taken into consideration in pre-operative assessment of cochlear implant candidates. (author)

  17. Bibliometrics analysis of the PubMed literatures on low-dose CT

    International Nuclear Information System (INIS)

    Wang Qian; Xia Guanghui; Ma Xiaohong; Zhao Xinming

    2012-01-01

    Objective: The purposes of this study were to evaluate the developmental rule and feature in low-dose CT examinations and to provide useful references for study in the future. Materials and Methods: The journal articles on PubMed from 2002 to 2011 were processed by Thomson Data Analyzer and five aspects were analysed: time, authors, institutions, journals, countries, and keywords. Results: The number of journal articles in low-dose CT examinations were 6 433, 3165 were from US (49.2%), 112 from China (1.4%); 3664 authors (80.42%) published only one article, the famous authors published more than 4 articles; there were 9 core journals in this area. In the last decade, the number and quality of the journal articles in low -dose CT have been dramatically increased. Conclusion: The interest on the low -dose CT examination has been steadily increasing, and world famous research teams have been established. The research in low-dose CT is a multi-discipline involving medicine, medical physics, and mathematics. Cooperation between multiple scientific domains is needed for the future studies. (authors)

  18. Precise Plan in the analysis of volume precision in SynergyTM conebeam CT image

    International Nuclear Information System (INIS)

    Bai Sen; Xu Qingfeng; Zhong Renming; Jiang Xiaoqin; Jiang Qingfeng; Xu Feng

    2007-01-01

    Objective: A method of checking the volume precision in Synergy TM conebeam CT image. Methods: To scan known phantoms (big, middle, small spheres, cubes and cuniform cavum) at different positions (CBCT centre and departure centre from 5, 8, 10 cm along the accelerator G-T way)with conebeam CT, the phantom volume of reconstructed images were measure. Then to compared measured volume of Synergy TM conebeam CT with fanbeam CT results and nominal values. Results: The middle spheres had 1.5% discrepancy in nominal values and metrical average values at CBCT centre and departure from centre 5, 8 cm along accelerator G-T way. The small spheres showed 8.1%, with 0.8 % of the big cube and 2.9% of small cube, in nominal values and metrical average values at CBCT centre and departure from centre 5, 8, 10 cm along the accelerator G-T way. Conclusion: In valid scan range of Synergy TM conebeam CT, reconstructed precision is independent of the distance deviation from the center. (authors)

  19. CT for suspected appendicitis in children: an analysis of diagnostic errors

    International Nuclear Information System (INIS)

    Taylor, George A.; Callahan, Michael J.; Rodriguez, Diana; Smink, Douglas S.

    2006-01-01

    Mistakes have been made by the use of CT in diagnosing children with suspected appendicitis. Although others have reported the frequency of diagnostic errors, we were unable to find any studies that addressed the specific situations in which diagnostic errors occurred in children with suspected appendicitis. To investigate the frequency and type of diagnostic errors resulting from CT of children with suspected appendicitis when compared to surgical and pathological diagnosis. We reviewed imaging, clinical and pathological data on 1,207 consecutive pediatric patients who underwent CT examination for suspected appendicitis. Imaging findings were categorized as false-positive, false-negative, or indeterminate. Errors were classified as interpretative, technical or unavoidable. Concordance between surgical and pathological findings was also evaluated. The imaging findings of 34 patients (2.8%) were discrepant with the pathological examination or clinical follow-up. The errors in 23 cases were classified as interpretive (68%) and 11 as unavoidable (32%), and no errors were classified as technical. There were 23 false-positive errors (68%), 6 false-negative errors (18%), and 5 indeterminate imaging studies (15%). Isolated CT findings of an enlarged (greater than 6 mm) appendix, fat stranding, thickened bowel or non-visualization of the distal appendix were the most common false-positive CT findings. Of these 34 patients, 22 underwent appendectomy, with 10 (45%) having discordant surgical and pathological findings. (orig.)

  20. CT and MRI analysis of central nervous system Rosai-Dorfman disease

    International Nuclear Information System (INIS)

    Zhang Jiatang; Lang Senyang; Pu Chuanqiang; Zhu Ruyuan; Wang Dianjun

    2008-01-01

    Objective: To study the CT and MRI imaging features of central nervous system Rosai-Dorfman disease and to enhance knowledge and differential diagnostic ability for central nervous system Rosai-Doffman disease. Methods: The CT and MRI imaging appearances in 4 cases of pathologically proven Rosai-Dorfman disease were retrospectively evaluated and the literature of central nervous system Rosai- Dorfman disease were reviewed. Results: Two cases had cranial CT scans, 4 cases had cranial MRI scans. On CT scans, cerebral edema was demonstrated in one case and the other case was normal. MRI scans showed the lesions were solitary in saddle area in 3 cases, and multiple in anterior cranial fossa in 1 case. The lesions exhibited iso- to hypointensity on both T 1 WI and T 2 WI images. Following intravenous injection of contrast medium, ring-like enhancement was seen in 2 cases and homogeneous enhancement in 1 case. Nodular enhancement was seen in the case of multiple lesions in the anterior cranial fossa. All lesions were dural-based. Conclusions: In patients with fever, headache, elevation of the erythrocyte sedimentation rate (ESR) and a polyclonal increase in γ-globulins, the possibility of central nervous system Rosai-Dorfman disease should be considered when single or multiple dural-based mass lesions, especially in sellar region, were identified by CT and MRI. (authors)

  1. Anticlockwise swirl of mesenteric vessels: A normal CT appearance, retrospective analysis of 200 pediatric patients

    Energy Technology Data Exchange (ETDEWEB)

    Sodhi, Kushaljit S., E-mail: sodhiks@gmail.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Bhatia, Anmol, E-mail: anmol_bhatia26@yahoo.co.in [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Saxena, Akshay K., E-mail: fatakshay@yahoo.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Rao, Katragadda L.N., E-mail: klnrao@hotmail.com [Department of Pediatric Surgery, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Menon, Prema, E-mail: menonprema@hotmail.com [Department of Pediatric Surgery, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Khandelwal, Niranjan, E-mail: khandelwaln@hotmail.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India)

    2014-04-15

    Objective: The counterclockwise rotation of the SMV on SMA is a normal and non-specific finding, which results in an incomplete swirl formation on CT scans. However, it has a potential to be misinterpreted as ‘midgut volvulus’ resulting in serious clinical implications. The study was done to determine the frequency and degree of counterclockwise rotation of the SMV on SMA on CT in normal otherwise asymptomatic pediatric patients undergoing CT scan. Methods: In this IRB approved study, we retrospectively analyzed abdominal CT scan examinations of 200 consecutive pediatric patients (age range of 11 days to 18 years), which were performed for different clinical indications over a period of 10 months. They were evaluated for the absence or presence and degree of counterclockwise rotation of the mesenteric vessels. Results: Of the 200 patients, 128 (64%) patients showed no clockwise or anticlockwise rotation of mesenteric vessels. Counterclockwise rotation of SMV on SMA was seen in 72 (36%) patients. Further, the degree of rotation of vessels was also calculated, based on the criteria proposed by the authors. Conclusions: The counterclockwise rotation of SMV on SMA gives an appearance of mesenteric whirlpool in otherwise normal mesenteric vessels and can be misinterpreted as midgut volvulus. It is a normal CT appearance and is due to a variation in branching pattern of mesenteric vessels. Awareness of this normal branching pattern of mesenteric vessels is important to avoid an inadvertent laparotomy.

  2. Anticlockwise swirl of mesenteric vessels: A normal CT appearance, retrospective analysis of 200 pediatric patients

    International Nuclear Information System (INIS)

    Sodhi, Kushaljit S.; Bhatia, Anmol; Saxena, Akshay K.; Rao, Katragadda L.N.; Menon, Prema; Khandelwal, Niranjan

    2014-01-01

    Objective: The counterclockwise rotation of the SMV on SMA is a normal and non-specific finding, which results in an incomplete swirl formation on CT scans. However, it has a potential to be misinterpreted as ‘midgut volvulus’ resulting in serious clinical implications. The study was done to determine the frequency and degree of counterclockwise rotation of the SMV on SMA on CT in normal otherwise asymptomatic pediatric patients undergoing CT scan. Methods: In this IRB approved study, we retrospectively analyzed abdominal CT scan examinations of 200 consecutive pediatric patients (age range of 11 days to 18 years), which were performed for different clinical indications over a period of 10 months. They were evaluated for the absence or presence and degree of counterclockwise rotation of the mesenteric vessels. Results: Of the 200 patients, 128 (64%) patients showed no clockwise or anticlockwise rotation of mesenteric vessels. Counterclockwise rotation of SMV on SMA was seen in 72 (36%) patients. Further, the degree of rotation of vessels was also calculated, based on the criteria proposed by the authors. Conclusions: The counterclockwise rotation of SMV on SMA gives an appearance of mesenteric whirlpool in otherwise normal mesenteric vessels and can be misinterpreted as midgut volvulus. It is a normal CT appearance and is due to a variation in branching pattern of mesenteric vessels. Awareness of this normal branching pattern of mesenteric vessels is important to avoid an inadvertent laparotomy

  3. CT-based morphometric analysis of the occipital condyle: focus on occipital condyle screw insertion.

    Science.gov (United States)

    Zhou, Jinsong; Espinoza Orías, Alejandro A; Kang, Xia; He, Jade; Zhang, Zhihai; Inoue, Nozomu; An, Howard S

    2016-11-01

    OBJECTIVE The segmental occipital condyle screw (OCS) is an alternative fixation technique in occipitocervical fusion. A thorough morphological study of the occipital condyle (OC) is critical for OCS placement. The authors set out to introduce a more precise CT-based method for morphometric analysis of the OC as it pertains to the placement of the segmental OCS, and they describe a novel preoperative simulation method for screw placement. Two new clinically relevant parameters, the height available for the OCS and the warning depth, are proposed. METHODS CT data sets from 27 fresh-frozen human cadaveric occipitocervical spines were used. All measurements were performed using a commercially available 3D reconstruction software package. The length, width, and sagittal angle of the condyle were measured in the axial plane at the base of the OC. The height of the OC and the height available for the segmental OCS were measured in the reconstructed oblique sagittal plane, fitting the ideal trajectory of the OCS recommended in the literature. The placement of a 3.5-mm-diameter screw that had the longest length of bicortical purchase was simulated into the OC in the oblique sagittal plane, with the screw path not being blocked by the occiput and not violating the hypoglossal canal cranially or the atlantooccipital joint caudally. The length of the simulated screw was recorded. The warning depth was measured as the shortest distance from the entry point of the screw to the posterior border of the hypoglossal canal. RESULTS The mean length and width of the OC were found to be larger in males: 22.2 ± 1.7 mm and 12.1 ± 1.0 mm, respectively, overall (p < 0.0001 for both). The mean sagittal angle was 28.0° ± 4.9°. The height available for the OCS was significantly less than the height of the OC (6.2 ± 1.3 mm vs 9.4 ± 1.5 mm, p < 0.0001). The mean screw length (19.3 ± 1.9 mm) also presented significant sex-related differences: male greater than female (p = 0.0002). The

  4. Diagnostic accuracy of dual-source CT coronary angiography in patients with atrial fibrillation: Meta analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gang, E-mail: cjr.sungang@vip.163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Min [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jiang, Zhi-wei [Department of Health Statistics, School of Public Health, Fourth Military Medical University, No. 169, Changle West Road, Xi’an, Shaanxi 710032 (China); Xu, Lin [Department of Medical Cardiology, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Peng, Zhao-hui; Ding, Juan; Li, Li [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jin, Zhi-tao [Department of Cardiology, General Hospital of the Second Artillery, Beijing 100088 (China)

    2013-10-01

    Rationale and objective: To synthesize the available data to underscore the diagnostic accuracy of dual-source CT (DSCT) coronary angiography in patients with atrial fibrillation (AF). Materials and methods: We searched in the electronic databases of PubMed for all published studies that examined patients with AF using DSCT. We used an exact binomial rendition of the bivariate mixed-effects regression model to synthesize the diagnostic data. Results: The positive and negative likelihood ratios (LRs) at the patient level were 6.0 (CI, 3.6–10.1) and 0.03(CI, 0.004–0.2), respectively. The negative predictive values higher than 90% were available for a CAD prevalence <78%. The pooled vessel- and segment-level estimates showed higher positive and negative LRs than the patient-level estimates (15.3 [CI, 9.8–23.9] and 0.1 [CI, 0.07–0.3]; 25.1 [CI, 10.8–58.5] and 0.2 [CI, 0.2–0.3], respectively). No statistically significant heterogeneity between studies and publication bias were found at the patient level estimate. A sensitivity analysis showed that no study influenced the pooled results larger than 0.02. Conclusions: Cardiac angiography with DSCT can be applied as an imaging test for ruling out CAD in patient with AF. However, DSCT angiography may be not an effective tool for risk stratification for the high negative LR at the artery and segment levels.

  5. 3D-CT imaging processing for qualitative and quantitative analysis of maxillofacial cysts and tumors

    International Nuclear Information System (INIS)

    Cavalcanti, Marcelo de Gusmao Paraiso; Antunes, Jose Leopoldo Ferreira

    2002-01-01

    The objective of this study was to evaluate spiral-computed tomography (3D-CT) images of 20 patients presenting with cysts and tumors in the maxillofacial complex, in order to compare the surface and volume techniques of image rendering. The qualitative and quantitative appraisal indicated that the volume technique allowed a more precise and accurate observation than the surface method. On the average, the measurements obtained by means of the 3D volume-rendering technique were 6.28% higher than those obtained by means of the surface method. The sensitivity of the 3D surface technique was lower than that of the 3D volume technique for all conditions stipulated in the diagnosis and evaluation of lesions. We concluded that the 3D-CT volume rendering technique was more reproducible and sensitive than the 3D-CT surface method, in the diagnosis, treatment planning and evaluation of maxillofacial lesions, especially those with intra-osseous involvement. (author)

  6. 3D-CT imaging processing for qualitative and quantitative analysis of maxillofacial cysts and tumors

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcanti, Marcelo de Gusmao Paraiso [Sao Paulo Univ., SP (Brazil). Faculdade de Odontologia. Dept. de Radiologia; Antunes, Jose Leopoldo Ferreira [Sao Paulo Univ., SP (Brazil). Faculdade de Odotologia. Dept. de Odontologia Social

    2002-09-01

    The objective of this study was to evaluate spiral-computed tomography (3D-CT) images of 20 patients presenting with cysts and tumors in the maxillofacial complex, in order to compare the surface and volume techniques of image rendering. The qualitative and quantitative appraisal indicated that the volume technique allowed a more precise and accurate observation than the surface method. On the average, the measurements obtained by means of the 3D volume-rendering technique were 6.28% higher than those obtained by means of the surface method. The sensitivity of the 3D surface technique was lower than that of the 3D volume technique for all conditions stipulated in the diagnosis and evaluation of lesions. We concluded that the 3D-CT volume rendering technique was more reproducible and sensitive than the 3D-CT surface method, in the diagnosis, treatment planning and evaluation of maxillofacial lesions, especially those with intra-osseous involvement. (author)

  7. Analysis of artifact and infrequent physiological uptake in 18F-FDG PET/CT

    International Nuclear Information System (INIS)

    Li Tianran; Zhao Chunlei; Qian Gennian; Chen Ziqian; Wang Kaitang; You Xueyu; Zheng Chunyu

    2006-01-01

    Objective: To explore the artifact and infrequent physiological uptake in PET/CT with its imaging and formation features. Methods: The data of PET/CT imaging were retrospectively analyzed and classified based on their cause. Besides, the infrequent physiological uptakes were also analyzed. Results: Artifacts could be classified into natural and technological causes. In natural causes, respiratory movement and high-density matters artifacts were frequently found, whereas in technological cause, the truncation, radioactive leakage and pollution commonly appeared. Infrequent physiological uptakes included uterine endometrium, breast and fat uptakes. Conclusions: The imaging features of artifact in PET can be divided into 'hot' or 'cold' area while infrequent physiological uptakes mainly are 'hot' area. Among the cause of artifact formation, CT-based attenuation corrected physical factor is the commonest. The infrequent physiological uptake somewhat relates to technological error. (authors)

  8. SU-F-BRF-10: Deformable MRI to CT Validation Employing Same Day Planning MRI for Surrogate Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Padgett, K; Stoyanova, R; Johnson, P; Dogan, N; Pollack, A [University of Miami School of Medicine, Miami, FL (United States); Piper, J; Javorek, A [MIM Software, Inc., Beachwood, OH (United States)

    2014-06-15

    Purpose: To compare rigid and deformable registrations of the prostate in the multi-modality setting (diagnostic-MRI to planning-CT) by utilizing a planning-MRI as a surrogate. The surrogate allows for the direct quantitative analysis which can be difficult in the multi-modality domain where intensity mapping differs. Methods: For ten subjects, T2 fast-spin-echo images were acquired at two different time points, the first several weeks prior to planning (diagnostic-MRI) and the second on the same day in which the planning CT was collected (planning-MRI). Significant effort in patient positioning and bowel/bladder preparation was undertaken to minimize distortion of the prostate in all datasets. The diagnostic-MRI was deformed to the planning-CT utilizing a commercially available deformable registration algorithm synthesized from local registrations. The deformed MRI was then rigidly aligned to the planning MRI which was used as the surrogate for the planning-CT. Agreement between the two MRI datasets was scored using intensity based metrics including Pearson correlation and normalized mutual information, NMI. A local analysis was performed by looking only within the prostate, proximal seminal vesicles, penile bulb and combined areas. A similar method was used to assess a rigid registration between the diagnostic-MRI and planning-CT. Results: Utilizing the NMI, the deformable registrations were superior to the rigid registrations in 9 of 10 cases demonstrating a 15.94% improvement (p-value < 0.001) within the combined area. The Pearson correlation showed similar results with the deformable registration superior in the same number of cases and demonstrating a 6.97% improvement (p-value <0.011). Conclusion: Validating deformable multi-modality registrations using spatial intensity based metrics is difficult due to the inherent differences in intensity mapping. This population provides an ideal testing ground for MRI to CT deformable registrations by obviating the need

  9. The registration accuracy analysis of different CT-MRI imaging fusion method in brain tumor

    International Nuclear Information System (INIS)

    Lu Jie; Yin Yong; Shao Qian; Zhang Zicheng; Chen Jinhu; Chen Zhaoqiu

    2010-01-01

    Objective: To find an effective CT-MRI image fusion protocol in brain tumor by analyzing the registration accuracy of different methods. Methods: The simulation CT scan and MRI T 1 WI imaging of 10 brain tumor patients obtained with same position were registered by Tris-Axes landmark ,Tris-Axes landmark + manual adjustment, mutual information and mutual information + manual adjustment method. The clinical tumor volume (CTV) were contoured on both CT and MRI images respectively. The accuracy of image fusion was assessed by the mean distance of five bone markers (d 1-5 ), central position of CTV (d CTV ) the percentage of CTV overlap (P CT-MRI ) between CT and MRI images. The difference between different methods was analyzed by Freedman M non-parameter test. Results: The difference of the means d1-5 between the Tris-Axes landmark,Tris-Axes landmark plus manual adjustment,mutual information and mutual information plus manual adjustment methods were 0.28 cm ±0.12 cm, 0.15 cm ±0.02 cm, 0.25 cm± 0.19 cm, 0.10 cm ± 0.06 cm, (M = 14.41, P = 0.002). the means d CTV were 0.59 cm ± 0.28 cm, 0.60 cm± 0.32 cm, 0.58 cm ± 0.39 cm, 0.42 cm± 0.30 cm (M = 9.72, P = 0.021), the means P CT-MRI were 0.69% ±0.18%, 0.68% ±0.16%, 0.66% ±0.17%, 0.74% ±0.14% (M =14.82, P=0.002), respectively. Conclusions: Mutual information plus manual adjustment registration method was the preferable fusion method for brain tumor patients. (authors)

  10. Can pleural adenosine deaminase (ADA) levels in pleural tuberculosis predict the presence of pulmonary tuberculosis? A CT analysis

    International Nuclear Information System (INIS)

    Koh, Myung Je; Lee, In Jae; Kim, Joo-Hee

    2016-01-01

    Aim: To assess the relationship between imaging features of pulmonary tuberculosis at computed tomography (CT) and adenosine deaminase (ADA) values via pleural fluid analysis in patients with pleural tuberculosis. Materials and methods: This retrospective study enrolled 60 patients who underwent fluid analysis for ADA and chest CT and were diagnosed with tuberculosis by culture or polymerase chain reaction of pleural fluid and sputum. The presence of centrilobular nodules, consolidation, cavitation, and mediastinal lymphadenopathy at CT were evaluated. The relationship between ADA values and the pattern of pulmonary involvement of tuberculosis was analysed. Results: Pulmonary involvement was seen in 42 of the 60 patients. A centrilobular nodular pattern was seen in 37 and consolidation in 22. In 17 patients, both findings were identified. A centrilobular nodular pattern was more common than consolidation or cavitary lesions. When ADA values were high, pulmonary involvement was more frequent (p=0.002). Comparing low and high ADA groups using an obtained cut-off value of 80 IU/l, the high group had more frequent pulmonary involvement (p<0.001). Conclusion: Patients with tuberculous pleurisy who had high ADA values had a higher probability of manifesting pulmonary tuberculosis. High ADA values may help predict contagious pleuroparenchymal tuberculosis. The most common pulmonary involvement of tuberculous pleurisy showed a centrilobular nodular pattern. - Highlights: • To know the relationship of ADA values and pulmonary involvement pattern of pleural tuberculosis. • To help exact diagnosis of pleuroparenchymal tuberculosis in clinical setting. • The imaging findings of pleuroparenchymal tuberculosis.

  11. Can pleural adenosine deaminase (ADA) levels in pleural tuberculosis predict the presence of pulmonary tuberculosis? A CT analysis.

    Science.gov (United States)

    Koh, Myung Je; Lee, In Jae; Kim, Joo-Hee

    2016-06-01

    To assess the relationship between imaging features of pulmonary tuberculosis at computed tomography (CT) and adenosine deaminase (ADA) values via pleural fluid analysis in patients with pleural tuberculosis. This retrospective study enrolled 60 patients who underwent fluid analysis for ADA and chest CT and were diagnosed with tuberculosis by culture or polymerase chain reaction of pleural fluid and sputum. The presence of centrilobular nodules, consolidation, cavitation, and mediastinal lymphadenopathy at CT were evaluated. The relationship between ADA values and the pattern of pulmonary involvement of tuberculosis was analysed. Pulmonary involvement was seen in 42 of the 60 patients. A centrilobular nodular pattern was seen in 37 and consolidation in 22. In 17 patients, both findings were identified. A centrilobular nodular pattern was more common than consolidation or cavitary lesions. When ADA values were high, pulmonary involvement was more frequent (p=0.002). Comparing low and high ADA groups using an obtained cut-off value of 80 IU/l, the high group had more frequent pulmonary involvement (pADA values had a higher probability of manifesting pulmonary tuberculosis. High ADA values may help predict contagious pleuroparenchymal tuberculosis. The most common pulmonary involvement of tuberculous pleurisy showed a centrilobular nodular pattern. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  12. Analysis of death in major trauma: value of prompt post mortem computed tomography (pmCT) in comparison to office hour autopsy.

    Science.gov (United States)

    Schmitt-Sody, Markus; Kurz, Stefanie; Reiser, Maximilian; Kanz, Karl Georg; Kirchhoff, Chlodwig; Peschel, Oliver; Kirchhoff, Sonja

    2016-03-29

    To analyze diagnostic accuracy of prompt post mortem Computed Tomography (pmCT) in determining causes of death in patients who died during trauma room management and to compare the results to gold standard autopsy during office hours. Multiple injured patients who died during trauma room care were enrolled. PmCT was performed immediately followed by autopsy during office hours. PmCT and autopsy were analyzed primarily regarding pmCT ability to find causes of death and secondarily to define exact causes of death including accurate anatomic localizations. For the secondary analysis data was divided in group-I with equal results of pmCT and autopsy, group-II with autopsy providing superior results and group-III with pmCT providing superior information contributing to but not majorly causing death. Seventeen multiple trauma patients were enrolled. Since multiple trauma patients were enrolled more injuries than patients are provided. Eight patients sustained deadly head injuries (47.1%), 11 chest (64.7%), 4 skeletal system (23.5%) injuries and one patient drowned (5.8%). Primary analysis revealed in 16/17 patients (94.1%) causes of death in accordance with autopsy. Secondary analysis revealed in 9/17 cases (group-I) good agreement of autopsy and pmCT. In seven cases autopsy provided superior results (group-II) whereas in 1 case pmCT found more information (group-III). The presented work studied the diagnostic value of pmCT in defining causes of death in comparison to standard autopsy. Primary analysis revealed that in 94.1% of cases pmCT was able to define causes of death even if only indirect signs were present. Secondary analysis showed that pmCT and autopsy showed equal results regarding causes of death in 52.9%. PmCT is useful in traumatic death allowing for an immediate identification of causes of death and providing detailed information on bony lesions, brain injuries and gas formations. It is advisable to conduct pmCT especially in cases without consent to

  13. CT analysis of 333 cases of congenital malformations of the external and middle ear

    International Nuclear Information System (INIS)

    Zou Xin; Li Qiang; Wang Zhenchang; Xian Junfang; Lan Baosen

    1997-01-01

    To analyze the different CT findings of congenital malformations of the external and middle ear, 333 cases including 404 ears with external and middle ear malformations diagnosed by high resolution CT (HRCT) were analysed according to the location and type of the malformation. In 404 ears, there were 364 ears with atresia of external auditory meatus, 40 ears with stenosis of external auditory meatus, 377 ears with malformation of the ossicles, 382 ears with stenosis of tympanum and 333 ears with anterior position of the mastoid segment of the facial canal. HRCT can show the location and type of external and middle ear malformation and provide valuable information for surgery

  14. Preoperative CT analysis of the mandible and maxilla for permanent dental prosthetic implantation

    International Nuclear Information System (INIS)

    Rothman, S.L.G.; Rhodes, M.L.; Schwarz, M.; Chafetz, N.I.

    1987-01-01

    The Branemark technique for permanently implanting dental prostheses is becoming universally accepted. The surgeon requires detailed knowledge of the cross-sectional anatomy of the alveolar ridges and inferior alveolar nerve for safe placement of the titanium fixtures. Axial CT scans of the mandible and maxilla, with oblique and panoramic CT reformations, were obtained in more than 100 patients. This report describes the anatomic variations in the maxilla and mandible as they relate to dental implantation surgery. The authors demonstrate the utility of this technique in preoperative surgical planning and postoperative evaluation

  15. Use of risk-matrix methods in the radiation safety analysis of PET/CT facilities

    International Nuclear Information System (INIS)

    Calderón Marín, Carlos F.; González González, Joaquín J.; Quesada Cepero, Waldo; Sinconegui Gómez, Belkys; Solá Rodríguez, Yeline; Duménigo Ámbar, Cruz; Guerrero Cancio, Mayka

    2016-01-01

    Introduction. Radiological safety is essential during clinical applications of ionizing radiations. Cuban legislation considers it mandatory to carry out risk analysis during safety assessments of facilities where Nuclear Medicine practices are performed. The Risk Matrix (R-M) method has been used in risk assessments in Radiotherapy and some experiences in Nuclear Medicine have been reported. In the present work the results of the safety evaluation, using the M-R method, of the first PET / CT center constructed at the Institute of Oncology and Radiobiology in Havana, are shown. The facilities will work as a satellite center and the production of radioactive drugs of 68 Ga will be conceived. The images will be acquired with a Philips Gemini TF64 scanner. Several stages and sub-stages were considered, including the design of the facility, quality control programs, review of the relevance of study requests, radiopharmaceutical reception and fractionation, 68 Ga radiopharmaceuticals production, management of Patient during the administration of radiopharmaceuticals and patient positioning. Initiating events (IEs), available barriers, as well as measures for the reduction of frequency (RFMs) of IEs and consequences (RCMs) were identified. In addition, IEs sequences are considered for CT scans. The incidence of risk reduction was assessed by the ratio of the number of times they were used and the total number of IEs. The calculation of the R-M was made by modeling the practice with the SEVRRA code R iskAssessmentSystem . Results. As a result, 76 IEs were identified with a distribution of 72% affecting patients, 7.9% in the Public and 19.7% on Occupationally Exposed Workers (TOEs). 89.5% of IEs are caused by human errors. Barriers and consequences and frequency reducers produced a risk distribution of 2.6% of high risk IEs, 64.5% medium risk and 32.9% low risk. The high-risk IEs are related to errors in the calculation of the shielding requirements of the facility that

  16. Present and future in the use of micro-CT scanner 3D analysis for the study of dental and root canal morphology

    OpenAIRE

    Nicola M. Grande; Gianluca Plotino; Gianluca Gambarini; Luca Testarelli; Ferdinando D’Ambrosio; Raffaella Pecci; Rossella Bedini

    2012-01-01

    The goal of the present article is to illustrate and analyze the applications and the potential of microcomputed tomography (micro-CT) in the analysis of tooth anatomy and root canal morphology. The authors performed a micro-CT analysis of the following different teeth: maxillary first molars with a second canal in the mesiobuccal (MB) root, mandibular first molars with complex anatomy in the mesial root, premolars with single and double roots and with complicated apical anatomy. The hardware...

  17. Focal breast lesions in clinical CT examinations of the chest. A retrospective analysis

    International Nuclear Information System (INIS)

    Krug, Kathrin Barbara; Houbois, Christian; Grinstein, Olga; Borggrefe, Jan; Puesken, Michael; Maintz, David; Hanstein, Bettina; Malter, Wolfram; Hellmich, Martin

    2017-01-01

    Based on radiological reports, the percentage of breast cancers visualized as incidental findings in routine CT examinations is estimated at ≤2%. In view of the rising number of CT examinations and the high prevalence of breast cancer, it was the goal of the present study to verify the frequency and image morphology of false-negative senological CT findings. All first contrast-enhanced CT examinations of the chest in adult female patients carried out in 2012 were retrospectively included. A senior radiologist systematically assessed the presence of breast lesions on all CT images using the BI-RADS system. All BI-RADS ≥3 notations were evaluated by a second senior radiologist. A consensus was obtained in case of differing BI-RADS assessments. Reference diagnoses were elaborated based on all available clinical, radiological and pathological data. The findings of the CT reports were classified according to the BI-RADS system and were compared with the retrospective consensus findings as well as with the reference diagnoses. The range of indications comprised a broad spectrum including staging and follow-up examinations of solid tumors/lymphoma (N = 701, 59.9 %) and vascular (190, 16.2 %), inflammatory (48, 4.1 %) and pulmonologic (22, 1.9 %) issues. BI-RADS 1/2 classifications were present in 92.5 % and BI-RADS 6 classifications were assessed in 1.7 % of the 1170 included examinations. 68 patients (5.8 %) had at least one lesion retrospectively classified as BI-RADS 3 - 5. The histological potential was known in 57 of these lesions as benign (46, 3.9 %) or malignant (11, 0.9 %). 13 BI-RADS 4/5 consensus assessments (1.1 %) were false-positive. 2 of the 10 lesions classified as being malignant based on the further clinical and radiological course were not mentioned in the written CT reports (0.2 %). Both false-negative CT reports were therapeutically and prognostically irrelevant. The relative frequency of BI-RADS 3 - 5 findings was 5.8 %. It reflects the situation

  18. Estimation of lung tumor position from multiple anatomical features on 4D-CT using multiple regression analysis.

    Science.gov (United States)

    Ono, Tomohiro; Nakamura, Mitsuhiro; Hirose, Yoshinori; Kitsuda, Kenji; Ono, Yuka; Ishigaki, Takashi; Hiraoka, Masahiro

    2017-09-01

    To estimate the lung tumor position from multiple anatomical features on four-dimensional computed tomography (4D-CT) data sets using single regression analysis (SRA) and multiple regression analysis (MRA) approach and evaluate an impact of the approach on internal target volume (ITV) for stereotactic body radiotherapy (SBRT) of the lung. Eleven consecutive lung cancer patients (12 cases) underwent 4D-CT scanning. The three-dimensional (3D) lung tumor motion exceeded 5 mm. The 3D tumor position and anatomical features, including lung volume, diaphragm, abdominal wall, and chest wall positions, were measured on 4D-CT images. The tumor position was estimated by SRA using each anatomical feature and MRA using all anatomical features. The difference between the actual and estimated tumor positions was defined as the root-mean-square error (RMSE). A standard partial regression coefficient for the MRA was evaluated. The 3D lung tumor position showed a high correlation with the lung volume (R = 0.92 ± 0.10). Additionally, ITVs derived from SRA and MRA approaches were compared with ITV derived from contouring gross tumor volumes on all 10 phases of the 4D-CT (conventional ITV). The RMSE of the SRA was within 3.7 mm in all directions. Also, the RMSE of the MRA was within 1.6 mm in all directions. The standard partial regression coefficient for the lung volume was the largest and had the most influence on the estimated tumor position. Compared with conventional ITV, average percentage decrease of ITV were 31.9% and 38.3% using SRA and MRA approaches, respectively. The estimation accuracy of lung tumor position was improved by the MRA approach, which provided smaller ITV than conventional ITV. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  19. Comprehensive Assessment of Coronary Artery Disease by Using First-Pass Analysis Dynamic CT Perfusion: Validation in a Swine Model.

    Science.gov (United States)

    Hubbard, Logan; Lipinski, Jerry; Ziemer, Benjamin; Malkasian, Shant; Sadeghi, Bahman; Javan, Hanna; Groves, Elliott M; Dertli, Brian; Molloi, Sabee

    2018-01-01

    Purpose To retrospectively validate a first-pass analysis (FPA) technique that combines computed tomographic (CT) angiography and dynamic CT perfusion measurement into one low-dose examination. Materials and Methods The study was approved by the animal care committee. The FPA technique was retrospectively validated in six swine (mean weight, 37.3 kg ± 7.5 [standard deviation]) between April 2015 and October 2016. Four to five intermediate-severity stenoses were generated in the left anterior descending artery (LAD), and 20 contrast material-enhanced volume scans were acquired per stenosis. All volume scans were used for maximum slope model (MSM) perfusion measurement, but only two volume scans were used for FPA perfusion measurement. Perfusion measurements in the LAD, left circumflex artery (LCx), right coronary artery, and all three coronary arteries combined were compared with microsphere perfusion measurements by using regression, root-mean-square error, root-mean-square deviation, Lin concordance correlation, and diagnostic outcomes analysis. The CT dose index and size-specific dose estimate per two-volume FPA perfusion measurement were also determined. Results FPA and MSM perfusion measurements (P FPA and P MSM ) in all three coronary arteries combined were related to reference standard microsphere perfusion measurements (P MICRO ), as follows: P FPA_COMBINED = 1.02 P MICRO_COMBINED + 0.11 (r = 0.96) and P MSM_COMBINED = 0.28 P MICRO_COMBINED + 0.23 (r = 0.89). The CT dose index and size-specific dose estimate per two-volume FPA perfusion measurement were 10.8 and 17.8 mGy, respectively. Conclusion The FPA technique was retrospectively validated in a swine model and has the potential to be used for accurate, low-dose vessel-specific morphologic and physiologic assessment of coronary artery disease. © RSNA, 2017.

  20. Quantitative analysis of the dual-energy CT virtual spectral curve for focal liver lesions characterization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qi, E-mail: wq20@hotmail.com; Shi, Gaofeng, E-mail: gaofengs62@sina.com; Qi, Xiaohui, E-mail: qixiaohui1984@163.com; Fan, Xueli, E-mail: 407849960@qq.com; Wang, Lijia, E-mail: 893197597@qq.com

    2014-10-15

    Highlights: • We establish a feasible method using the virtual spectral curves (VSC) to differentiate focal liver lesions using DECT. • Our study shows the slope of the VSC can be used to differentiate between hemangioma, HCC, metastasis and cyst. • Importantly, the diagnostic specificities associated with using the slope to diagnose both hemangioma and cysts were 100%. - Abstract: Objective: To assess the usefulness of the spectral curve slope of dual-energy CT (DECT) for differentiating between hepatocellular carcinoma (HCC), hepatic metastasis, hemangioma (HH) and cysts. Methods: In total, 121 patients were imaged in the portal venous phase using dual-energy mode. Of these patients, 23 patients had HH, 28 patients had HCC, 40 patients had metastases and 30 patients had simple cysts. The spectral curves of the hepatic lesions were derived from the 40–190 keV levels of virtual monochromatic spectral imaging. The spectral curve slopes were calculated from 40 to 110 keV. The slopes were compared using the Kruskal–Wallis test. Receiver operating characteristic curves (ROC) were used to determine the optimal cut-off value of the slope of the spectral curve to differentiate between the lesions. Results: The spectral curves of the four lesion types had different baseline levels. The HH baseline level was the highest followed by HCC, metastases and cysts. The slopes of the spectral curves of HH, HCC, metastases and cysts were 3.81 ± 1.19, 1.49 ± 0.57, 1.06 ± 0.76 and 0.13 ± 0.17, respectively. These values were significantly different (P < 0.008). Based on ROC analysis, the respective diagnostic sensitivity and specificity were 87% and 100% for hemangioma (cut-off value ≥ 2.988), 82.1% and 65.9% for HCC (cut-off value 1.167–2.998), 65.9% and 59% for metastasis (cut-off value 0.133–1.167) and 44.4% and 100% for cysts (cut-off value ≤ 0.133). Conclusion: Quantitative analysis of the DECT spectral curve in the portal venous phase can be used to

  1. Quantitative analysis of spinal curvature in 3D: application to CT images of normal spine

    Energy Technology Data Exchange (ETDEWEB)

    Vrtovec, Tomaz; Likar, Bostjan; Pernus, Franjo [University of Ljubljana, Faculty of Electrical Engineering, Trzaska 25, SI-1000 Ljubljana (Slovenia)

    2008-04-07

    The purpose of this study is to present a framework for quantitative analysis of spinal curvature in 3D. In order to study the properties of such complex 3D structures, we propose two descriptors that capture the characteristics of spinal curvature in 3D. The descriptors are the geometric curvature (GC) and curvature angle (CA), which are independent of the orientation and size of spine anatomy. We demonstrate the two descriptors that characterize the spinal curvature in 3D on 30 computed tomography (CT) images of normal spine and on a scoliotic spine. The descriptors are determined from 3D vertebral body lines, which are obtained by two different methods. The first method is based on the least-squares technique that approximates the manually identified vertebra centroids, while the second method searches for vertebra centroids in an automated optimization scheme, based on computer-assisted image analysis. Polynomial functions of the fourth and fifth degree were used for the description of normal and scoliotic spinal curvature in 3D, respectively. The mean distance to vertebra centroids was 1.1 mm ({+-}0.6 mm) for the first and 2.1 mm ({+-}1.4 mm) for the second method. The distributions of GC and CA values were obtained along the 30 images of normal spine at each vertebral level and show that maximal thoracic kyphosis (TK), thoracolumbar junction (TJ) and maximal lumbar lordosis (LL) on average occur at T3/T4, T12/L1 and L4/L5, respectively. The main advantage of GC and CA is that the measurements are independent of the orientation and size of the spine, thus allowing objective intra- and inter-subject comparisons. The positions of maximal TK, TJ and maximal LL can be easily identified by observing the GC and CA distributions at different vertebral levels. The obtained courses of the GC and CA for the scoliotic spine were compared to the distributions of GC and CA for the normal spines. The significant difference in values indicates that the descriptors of GC and

  2. Quantitative analysis of spinal curvature in 3D: application to CT images of normal spine

    International Nuclear Information System (INIS)

    Vrtovec, Tomaz; Likar, Bostjan; Pernus, Franjo

    2008-01-01

    The purpose of this study is to present a framework for quantitative analysis of spinal curvature in 3D. In order to study the properties of such complex 3D structures, we propose two descriptors that capture the characteristics of spinal curvature in 3D. The descriptors are the geometric curvature (GC) and curvature angle (CA), which are independent of the orientation and size of spine anatomy. We demonstrate the two descriptors that characterize the spinal curvature in 3D on 30 computed tomography (CT) images of normal spine and on a scoliotic spine. The descriptors are determined from 3D vertebral body lines, which are obtained by two different methods. The first method is based on the least-squares technique that approximates the manually identified vertebra centroids, while the second method searches for vertebra centroids in an automated optimization scheme, based on computer-assisted image analysis. Polynomial functions of the fourth and fifth degree were used for the description of normal and scoliotic spinal curvature in 3D, respectively. The mean distance to vertebra centroids was 1.1 mm (±0.6 mm) for the first and 2.1 mm (±1.4 mm) for the second method. The distributions of GC and CA values were obtained along the 30 images of normal spine at each vertebral level and show that maximal thoracic kyphosis (TK), thoracolumbar junction (TJ) and maximal lumbar lordosis (LL) on average occur at T3/T4, T12/L1 and L4/L5, respectively. The main advantage of GC and CA is that the measurements are independent of the orientation and size of the spine, thus allowing objective intra- and inter-subject comparisons. The positions of maximal TK, TJ and maximal LL can be easily identified by observing the GC and CA distributions at different vertebral levels. The obtained courses of the GC and CA for the scoliotic spine were compared to the distributions of GC and CA for the normal spines. The significant difference in values indicates that the descriptors of GC and CA

  3. Prediction of the therapeutic response after FOLFOX and FOLFIRI treatment for patients with liver metastasis from colorectal cancer using computerized CT texture analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Su Joa, E-mail: joa0827@gmail.com [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Jung Hoon, E-mail: jhkim2008@gmail.com [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Park, Sang Joon, E-mail: lunao78@naver.com [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Cancer Research Institute, Seoul National University, Seoul (Korea, Republic of); Han, Joon Koo, E-mail: hanjk@snu.ac.kr [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2016-10-15

    Purpose: To determine whether baseline CT texture analysis of hepatic metastasis from colorectal cancer (CRC) is predictive of therapeutic response after cytotoxic chemotherapy. Materials and methods: 235 patients with liver metastasis from CRC who underwent CT and cytotoxic chemotherapy using FOLFOX and FOLFIRI were divided into derivation cohort (n = 145) and validation cohort (n = 90). The CT texture of the hepatic metastasis was quantified using baseline CT. We analyzed the independent predictor for the response from derivation cohort and validated it using validation cohort. We also compared texture features between included four CT scanners. Results: 89 responding and 146 non-responding patients were evaluated. In the derivation cohort, lower skewness (OR, 6.739) in 2D, higher mean attenuation (OR, 2.587), and narrower standard deviation (SD) (OR, 3.163) in 3D were independently associated with response to chemotherapy. However, only lower skewness (P=0.213) on 2D and narrower SD on 3D analysis (P=0.097) did not show a significant difference on either CT scanner. When applied to the validation set, the lower skewness on 2D (AUC = 0.797) and narrower SD on 3D (AUC = 0.785) showed good performance. Conclusion: CT texture analysis is useful for prediction of therapeutic response after cytotoxic chemotherapy in patients with liver metastasis from colorectal cancer.

  4. CT in the staging of bronchogenic carcinoma: Analysis by correlative lymph node mapping and sampling

    International Nuclear Information System (INIS)

    McLoud, T.C.; Woldenberg, R.; Mathisen, D.J.; Grillo, H.C.; Bourgoulin, P.M.; Shepard, J.O.; Moore, E.H.

    1987-01-01

    Although previous studies have evaluated the accuracy of CT in staging the mediastinum in bronchogenic carcinoma, none has determined the sensitivity and specificity of CT in the assessment of individual lymph node groups by correlative nodal sampling at surgery. CT scans were performed on 84 patients with bronchogenic carcinoma. Abnormal nodes (≥ 1 cm) were localized according to the ATS classification of regional lymph node mapping. Seventy-nine patients had mediastinoscopy and 64 patients underwent thoracotomy. In each case, biopsies of lymph node groups 2R, 4R, 2L, 4L (paratracheal), 7 (subcarinal), and 5 (aorticopulmonary) were performed on the appropriate side. Hilar nodes (10R and 11R, 10L and 11L) were resected with the surgical specimen. A total of 292 nodes were sampled. Overall sensitivity for all lymph node groups was 40%, and specificity, 81%. Sensitivity was highest for the 4R (paratracheal) group (82%) and lowest for the subcarinal area (20%). Specificity ranged from 71% for 11R nodes (right hilar) to 94% for 10L (left peribronchial). The positive predictive value was 34%, and the negative predictive value, 84%. This study suggests that the more optimistic results previously reported may have resulted from lack of correlation of individual lymph node groups identified on CT with those sampled at surgery

  5. Phylogenetic ctDNA analysis depicts early stage lung cancer evolution

    DEFF Research Database (Denmark)

    Abbosh, Christopher; Birkbak, Nicolai Juul; Wilson, Gareth A.

    2017-01-01

    The early detection of relapse following primary surgery for non-small cell lung cancer and the characterization of emerging subclones seeding metastatic sites might offer new therapeutic approaches to limit tumor recurrence. The potential to non-invasively track tumor evolutionary dynamics in ct...

  6. CT image and clinical analysis of the term neonatal hypoxic-ischemic encephalopathy

    International Nuclear Information System (INIS)

    Zhan Zhigang; Zheng Keguo

    2006-01-01

    Objective: This is a retrospective investigation of 87 cases of perinatal HIE diagnosed in Junan hospital with literature review, made to improve the diagnosis of HIE, and provide objective information as well as the principle for clinical management and prognosis. Methods: In total 87 patients with HIE, including 52 males and 25 females, aged from 38 weeks to 42 weeks, underwent examination in 1 hour to 16 days after the delivery. There was natural labor in 39 cases, vacuum labor in 11 cases, forceps delivery in 9 cases, abdominal delivery in 6 cases. All the neonatal infants had a history of asphyxia on different levels. Results: CT scan showed diffuse or asymmetrical hypodense shadows with poorly-defined border, where the CT value measured between 10-18 HU, accompanying with the displacement or even absence of lateral ventricle. Subarachnoid hemorrhage (SAH) were found in 34 cases (39.5%), parenchyma hemorrhage in 24 cases (27.6%), intraventricular hemorrhage (IVH) in 15 cases (17.2%), and subdural hemorrhage in 5 cases (5.7%). Additionally, scalp turgidity was seen in 11 cases, and skull fracture in 4 cases as well. Conclusion: The CT scan shows the anoxicasphyxial lesions in the brain resulting from asphyxiation in neonatal, and the severity is rated with CT manifestation and brain edema, which provide objective guidance of the prognosis and the clinical management of HIE. (authors)

  7. Analysis of thyroid absorbed dose in cervical CT scan with the use of bismuth shielding

    International Nuclear Information System (INIS)

    Santos, Fernanda S.; Gómez, Álvaro M.L.; Mourão, Arnaldo P.; Santana, Priscila C.

    2017-01-01

    The Computed Tomography (CT) has become an important tool to diagnose cancer and to obtain additional information for different clinical questions. Today, it is a very fast, painless and noninvasive test that can be performed high quality images. However, CT scan usually requires a higher radiation exposure dose than a conventional radiography examination. The aim of this study is to determine the dose variation deposited in thyroid and in nearby radiosensitive organs, such as: lenses, pharynx, hypophysis, salivary gland and spinal cord with and without the use of bismuth shielded. A cervical CT scan was performed on anthropomorphic male phantom model Alderson Rando, from the occipital to the first thoracic vertebra, using a GE scanner, Discovery model with 64 channels. Dose measurements have been performed by using radiochromic film strips to register the individual doses in the organs of interest. After the phantom cervical CT scan the radiochromic film strips were processed for obtaining digital images. Digital images were worked to obtain the dose variation profiles for each film. With the data obtained, it was found the organ dose variation. The results show that the thyroid received the highest dose, 40.9 mGy, in the phantom, according to the incidence of the primary X-ray beam. (author)

  8. Progress in analysis of computed tomography (CT) images of hardwood logs for defect detection

    Science.gov (United States)

    Erol Sarigul; A. Lynn Abbott; Daniel L. Schmoldt

    2003-01-01

    This paper addresses the problem of automatically detecting internal defects in logs using computed tomography (CT) images. The overall purpose is to assist in breakdown optimization. Several studies have shown that the commercial value of resulting boards can be increased substantially if defect locations are known in advance, and if this information is used to make...

  9. Pulmonary involvement in Churg-Strauss syndrome: an analysis of CT, clinical, and pathologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon Kyung; Lee, Kyung Soo; Chong, Semin; Chung, Myung Jin; Yi, Chin A; Kim, Ha Young [Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea); Chung, Man Pyo [Samsung Medical Center, Sungkyunkwan University School of Medicine, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Seoul (Korea); Han, Joungho [Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Pathology, Seoul (Korea)

    2007-12-15

    We tried to assess retrospectively thin-section CT findings of Churg-Strauss syndrome (CSS) in 25 patients and to compare these findings with clinical and histopathologic findings. Of 25 patients, 19 (76%) had parenchymal abnormalities at CT; small nodules (n = 12; 63%), ground-glass opacity (n = 10; 53%), bronchial wall thickening (n = 10; 53%), and consolidation (n = 8; 42%). Parenchymal abnormalities (n = 19) were categorizable as an airway pattern in 11 and an airspace pattern in eight. Patients with an airway pattern (n = 5) had obstructive (n = 3) or combined (n = 2) PFT results, whereas those with an airspace pattern (n = 4) had restrictive (n = 3) or obstructive (n = 1) results. Parenchymal opacities at CT corresponded histologically to areas of eosinophilic pneumonia, necrotizing granulomas, and granulomatous vasculitis; small nodules to eosinophilic bronchiolitis and peribronchiolar vasculitis; and bronchial wall thickening to airway wall eosinophil and lymphocyte infiltration. Patients with airspace pattern responded more readily to treatment than those with airway pattern. CT shows lung parenchymal abnormalities in about three-quarters of CSS patients and these abnormalities can be categorized as airspace or airway patterns. This classification helps predict PFT data, underlying histopathology, and treatment response. (orig.)

  10. Pulmonary involvement in Churg-Strauss syndrome: an analysis of CT, clinical, and pathologic findings

    International Nuclear Information System (INIS)

    Kim, Yoon Kyung; Lee, Kyung Soo; Chong, Semin; Chung, Myung Jin; Yi, Chin A.; Kim, Ha Young; Chung, Man Pyo; Han, Joungho

    2007-01-01

    We tried to assess retrospectively thin-section CT findings of Churg-Strauss syndrome (CSS) in 25 patients and to compare these findings with clinical and histopathologic findings. Of 25 patients, 19 (76%) had parenchymal abnormalities at CT; small nodules (n = 12; 63%), ground-glass opacity (n = 10; 53%), bronchial wall thickening (n = 10; 53%), and consolidation (n = 8; 42%). Parenchymal abnormalities (n = 19) were categorizable as an airway pattern in 11 and an airspace pattern in eight. Patients with an airway pattern (n = 5) had obstructive (n = 3) or combined (n = 2) PFT results, whereas those with an airspace pattern (n = 4) had restrictive (n = 3) or obstructive (n = 1) results. Parenchymal opacities at CT corresponded histologically to areas of eosinophilic pneumonia, necrotizing granulomas, and granulomatous vasculitis; small nodules to eosinophilic bronchiolitis and peribronchiolar vasculitis; and bronchial wall thickening to airway wall eosinophil and lymphocyte infiltration. Patients with airspace pattern responded more readily to treatment than those with airway pattern. CT shows lung parenchymal abnormalities in about three-quarters of CSS patients and these abnormalities can be categorized as airspace or airway patterns. This classification helps predict PFT data, underlying histopathology, and treatment response. (orig.)

  11. The bibliometric analysis of literatures on low-dose CT in CNKI

    International Nuclear Information System (INIS)

    Wang Qian; Qi Weiwei; Xia Guanghui; Zhao Xinming; Ma Xiaohong; Zhou Chunwu; Hong Nan

    2013-01-01

    Objective: The purposes of this study were to evaluate the characteristics and rule of the development in national low -dose CT examination, and to supply a useful reference for future studies. Materials and Methods: The journal articles in CNKI which were included by China Academic Journal Network Publishing Database (CAJD) from 2002 to 2011 were processed with Thomson Data Analyzer (TDA). Seven aspects were analyzed: time, authors, funds for scientific research, areal distribution, institutions, authors, and keywords. Results: A total 3148 journal articles on low-dose CT examination and 7352 authors were found. The cooperative rate and degree were 63, 48% and 2.34, respectively. The famous authors were those who published more than 3 articles. Authors were from 33 areas, 471 institutions of 8 systems. Beijing and Shanghai were the most productive areas, publishing 45.9% articles. There were 10 core journals in this research area, 868 articles were funded by certain grants, and number of articles was increased yearly, indicative of the importance of grant in promoting research. Conclusion: The national low-dose CT research was in the young stage compared to the international research, and the research were not evenly distributed national wide. Though the researches have involved multi-institute, multi-system, multi-discipline, the quantities and qualities of papers still have improvement space. Strengthening basic research, improving medical ethics, and optimizing clinical research methods would promote development of low-dose CT studies. (authors)

  12. Analysis of thyroid absorbed dose in cervical CT scan with the use of bismuth shielding

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Fernanda S.; Gómez, Álvaro M.L.; Mourão, Arnaldo P., E-mail: fernanda.stephaniebh@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Santana, Priscila C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem

    2017-07-01

    The Computed Tomography (CT) has become an important tool to diagnose cancer and to obtain additional information for different clinical questions. Today, it is a very fast, painless and noninvasive test that can be performed high quality images. However, CT scan usually requires a higher radiation exposure dose than a conventional radiography examination. The aim of this study is to determine the dose variation deposited in thyroid and in nearby radiosensitive organs, such as: lenses, pharynx, hypophysis, salivary gland and spinal cord with and without the use of bismuth shielded. A cervical CT scan was performed on anthropomorphic male phantom model Alderson Rando, from the occipital to the first thoracic vertebra, using a GE scanner, Discovery model with 64 channels. Dose measurements have been performed by using radiochromic film strips to register the individual doses in the organs of interest. After the phantom cervical CT scan the radiochromic film strips were processed for obtaining digital images. Digital images were worked to obtain the dose variation profiles for each film. With the data obtained, it was found the organ dose variation. The results show that the thyroid received the highest dose, 40.9 mGy, in the phantom, according to the incidence of the primary X-ray beam. (author)

  13. CT analysis of peripheral airway and lung lesions of patients with asthma and COPD

    International Nuclear Information System (INIS)

    Itoh, Takayuki; Tanaka, Hiroshi; Sahara, Shin; Ohnishi, Tetsuro; Abe, Shosaku; Ueno, Kan

    2002-01-01

    We compared peripheral airway and lung parenchyma images among patients with asthma, chronic obstructive pulmonary disease (COPD) and healthy controls using high-resolution CT images taken by a multidetector-row CT scanner (Aquillion, Toshiba, Japan). CT images were saved as digital image and communication (DICOM) files and %low attenuation area (LAA) (<-960 Hounsfield Unit) was calculated with the imaging software. %LAA was significantly increased in patients with COPD (p<0.0001) and smokers with stable asthma (p<0.01) as compared with healthy controls. In stable asthma, mucous plugging in the airway sometime appeared, while during asthma exacerbation small nodules and mosaic pattern of peripheral lung field appeared. Since smoker's patients with asthma have hyper-secretion of sputum due to smoking, mucous plugging and airway inflammation may easily occur and consequently air trapping may increase. In the future, image diagnosis of peripheral airway should develop for early detection of airway diseases as a non-invasive examination. On the other hand, micro focus X-ray computed tomography system (Hitachi Medico Technology Co., Japan) can display CT images closely similar to the pictures of microscopic findings and it will be a useful tool to analyze radiologic-pathologic correlations of peripheral airways and lung parenchyma. (author)

  14. CT features of focal organizing pneumonia: An analysis of consecutive histopathologically confirmed 45 cases

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Feng [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, 310016 (China); Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR (China); Yan, Sen-Xiang [Department of Radiation Oncology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003 (China); Wang, Gao-Feng [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, 310016 (China); Wang, Jin [Department of Pathology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, 310016 (China); Lu, Pu-Xuan [Department of Radiology, Shenzhen Third People' s Hospital, Guangdong Medical College, Shenzhen, 518020 (China); Chen, Bin [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, 310016 (China); Yuan, Jing [Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR (China); Zhang, Shi-Zheng, E-mail: shizhengzhang@hotmail.com [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, 310016 (China); Wang, Yi-Xiang J., E-mail: yixiang_wang@cuhk.edu.hk [Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR (China); Department of Radiology, Shenzhen Third People' s Hospital, Guangdong Medical College, Shenzhen, 518020 (China)

    2014-01-15

    Objective: To study the CT characteristics of solitary focal organizing pneumonia (FOP). Materials and methods: Chest CT of consecutive 45 patients (34 males and 11 females, median age: 56 years) with confirmed FOP were analyzed. The CT features between large FOP (>3 cm, n = 27) and small FOP (≤3 cm, n = 18) were compared. Results: FOP lesions predominately located in peripheral lungs (86.7%), with the right lower lobe being most common lobe (44.4%). No lesion mainly located in the inner 1/3 of lungs. All large lesions were polygon in shape and had an irregular margin, while small lesions were more likely to be round or oval with an irregular or smooth border. Air bronchogram or small bubble-like lucency was present in majority of the lesions. 42.2% of lesions had incompact internal structure with inhomogeneous density besides air component. Most lesions were associated with a contraction or convergence of surrounding vessels; while no pulmonary vessel was interrupted abruptly by a small FOP lesion. Majority of large lesions had broad contact with the pleura, while only one patient had mild pleural effusion. Mild mediastinal lymph nodes enlargement was present in about 1/5 of the patients. Conclusion: Compared with the known CT features of lung cancer, our results suggest differential diagnosis can often be made for large FOP, while small FOP may resemble lung cancer.

  15. CT and MR features of xanthogranulomatous cholecystitis: An analysis of consecutive 49 cases

    International Nuclear Information System (INIS)

    Zhao, Feng; Lu, Pu-Xuan; Yan, Sen-Xiang; Wang, Gao-Feng; Yuan, Jing; Zhang, Shi-Zheng; Wang, Yi-Xiang J.

    2013-01-01

    Objective: To study the CT and MR features of xanthogranulomatous cholecystitis (XGC). Materials and methods: 49 patients had pathologically confirmed XGC. All patients underwent contrast enhanced CT, and 10 patients had additional plain MRI. The CT and MRI results were retrospectively analyzed. Results: On CT, all patients had thickening of gallbladder wall, with 87.8% cases showed diffuse thickening. 85.7% cases had intramural hypo-attenuated nodules in the thickened wall. Continuous mucosal line and luminal surface enhancement were noted in 79.6% and 85.7% cases, respectively. Gallbladder stones were seen in 69.4% patients. The coexistence of the above 5 CT features was seen in 40% cases, and 80% cases had the coexistence of ≥4 features. Diffused gallbladder wall thickening in XGC is more likely to have disrupted mucosal line, and XGC with disrupted mucosal line is more likely to be associated with liver infiltration. In 60% patients the inflammatory process extended beyond gallbladder, with the interface between gallbladder and liver and/or the surrounding fat blurred. 40% cases had an early enhancement of liver parenchyma. Infiltration to other surrounding tissues included bowel (n = 3), stomach (n = 2), and abdominal wall (n = 1). On MR images, 7 of 9 intramural nodules in 7 subjects with T1-weighted dual echo MR images showed higher signal intensity on in-phase images than out-of-phase images. Conclusion: Coexisting of diffuse gallbladder wall thickening, hypo-attenuated intramural nodules, continuous mucosal line, luminal surface enhancement, and gallbladder stone highly suggest XGC. XGC frequently infiltrate liver and surrounding fat. Chemical-shift MRI helps classifying intramural nodules in the gallbladder wall

  16. CT and MR features of xanthogranulomatous cholecystitis: An analysis of consecutive 49 cases

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Feng [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016 (China); Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong (China); Lu, Pu-Xuan [Department of Radiology, Shenzhen Third People' s Hospital, Guangdong Medical College, Shenzhen 518020 (China); Yan, Sen-Xiang [Department of Radiation Oncology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003 (China); Wang, Gao-Feng [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016 (China); Yuan, Jing [Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong (China); Zhang, Shi-Zheng, E-mail: shizhengzhang@hotmail.com [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016 (China); Wang, Yi-Xiang J., E-mail: yixiang_wang@cuhk.edu.hk [Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong (China); Department of Radiology, Shenzhen Third People' s Hospital, Guangdong Medical College, Shenzhen 518020 (China)

    2013-09-15

    Objective: To study the CT and MR features of xanthogranulomatous cholecystitis (XGC). Materials and methods: 49 patients had pathologically confirmed XGC. All patients underwent contrast enhanced CT, and 10 patients had additional plain MRI. The CT and MRI results were retrospectively analyzed. Results: On CT, all patients had thickening of gallbladder wall, with 87.8% cases showed diffuse thickening. 85.7% cases had intramural hypo-attenuated nodules in the thickened wall. Continuous mucosal line and luminal surface enhancement were noted in 79.6% and 85.7% cases, respectively. Gallbladder stones were seen in 69.4% patients. The coexistence of the above 5 CT features was seen in 40% cases, and 80% cases had the coexistence of ≥4 features. Diffused gallbladder wall thickening in XGC is more likely to have disrupted mucosal line, and XGC with disrupted mucosal line is more likely to be associated with liver infiltration. In 60% patients the inflammatory process extended beyond gallbladder, with the interface between gallbladder and liver and/or the surrounding fat blurred. 40% cases had an early enhancement of liver parenchyma. Infiltration to other surrounding tissues included bowel (n = 3), stomach (n = 2), and abdominal wall (n = 1). On MR images, 7 of 9 intramural nodules in 7 subjects with T1-weighted dual echo MR images showed higher signal intensity on in-phase images than out-of-phase images. Conclusion: Coexisting of diffuse gallbladder wall thickening, hypo-attenuated intramural nodules, continuous mucosal line, luminal surface enhancement, and gallbladder stone highly suggest XGC. XGC frequently infiltrate liver and surrounding fat. Chemical-shift MRI helps classifying intramural nodules in the gallbladder wall.

  17. Histogram Analysis of CT Perfusion of Hepatocellular Carcinoma for Predicting Response to Transarterial Radioembolization: Value of Tumor Heterogeneity Assessment

    International Nuclear Information System (INIS)

    Reiner, Caecilia S.; Gordic, Sonja; Puippe, Gilbert; Morsbach, Fabian; Wurnig, Moritz; Schaefer, Niklaus; Veit-Haibach, Patrick; Pfammatter, Thomas; Alkadhi, Hatem

    2016-01-01

    PurposeTo evaluate in patients with hepatocellular carcinoma (HCC), whether assessment of tumor heterogeneity by histogram analysis of computed tomography (CT) perfusion helps predicting response to transarterial radioembolization (TARE).Materials and MethodsSixteen patients (15 male; mean age 65 years; age range 47–80 years) with HCC underwent CT liver perfusion for treatment planning prior to TARE with Yttrium-90 microspheres. Arterial perfusion (AP) derived from CT perfusion was measured in the entire tumor volume, and heterogeneity was analyzed voxel-wise by histogram analysis. Response to TARE was evaluated on follow-up imaging (median follow-up, 129 days) based on modified Response Evaluation Criteria in Solid Tumors (mRECIST). Results of histogram analysis and mean AP values of the tumor were compared between responders and non-responders. Receiver operating characteristics were calculated to determine the parameters’ ability to discriminate responders from non-responders.ResultsAccording to mRECIST, 8 patients (50 %) were responders and 8 (50 %) non-responders. Comparing responders and non-responders, the 50th and 75th percentile of AP derived from histogram analysis was significantly different [AP 43.8/54.3 vs. 27.6/34.3 mL min −1  100 mL −1 ); p < 0.05], while the mean AP of HCCs (43.5 vs. 27.9 mL min −1  100 mL −1 ; p > 0.05) was not. Further heterogeneity parameters from histogram analysis (skewness, coefficient of variation, and 25th percentile) did not differ between responders and non-responders (p > 0.05). If the cut-off for the 75th percentile was set to an AP of 37.5 mL min −1  100 mL −1 , therapy response could be predicted with a sensitivity of 88 % (7/8) and specificity of 75 % (6/8).ConclusionVoxel-wise histogram analysis of pretreatment CT perfusion indicating tumor heterogeneity of HCC improves the pretreatment prediction of response to TARE

  18. Histogram Analysis of CT Perfusion of Hepatocellular Carcinoma for Predicting Response to Transarterial Radioembolization: Value of Tumor Heterogeneity Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Reiner, Caecilia S., E-mail: caecilia.reiner@usz.ch; Gordic, Sonja; Puippe, Gilbert; Morsbach, Fabian; Wurnig, Moritz [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology (Switzerland); Schaefer, Niklaus; Veit-Haibach, Patrick [University Hospital Zurich, Division of Nuclear Medicine (Switzerland); Pfammatter, Thomas; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology (Switzerland)

    2016-03-15

    PurposeTo evaluate in patients with hepatocellular carcinoma (HCC), whether assessment of tumor heterogeneity by histogram analysis of computed tomography (CT) perfusion helps predicting response to transarterial radioembolization (TARE).Materials and MethodsSixteen patients (15 male; mean age 65 years; age range 47–80 years) with HCC underwent CT liver perfusion for treatment planning prior to TARE with Yttrium-90 microspheres. Arterial perfusion (AP) derived from CT perfusion was measured in the entire tumor volume, and heterogeneity was analyzed voxel-wise by histogram analysis. Response to TARE was evaluated on follow-up imaging (median follow-up, 129 days) based on modified Response Evaluation Criteria in Solid Tumors (mRECIST). Results of histogram analysis and mean AP values of the tumor were compared between responders and non-responders. Receiver operating characteristics were calculated to determine the parameters’ ability to discriminate responders from non-responders.ResultsAccording to mRECIST, 8 patients (50 %) were responders and 8 (50 %) non-responders. Comparing responders and non-responders, the 50th and 75th percentile of AP derived from histogram analysis was significantly different [AP 43.8/54.3 vs. 27.6/34.3 mL min{sup −1} 100 mL{sup −1}); p < 0.05], while the mean AP of HCCs (43.5 vs. 27.9 mL min{sup −1} 100 mL{sup −1}; p > 0.05) was not. Further heterogeneity parameters from histogram analysis (skewness, coefficient of variation, and 25th percentile) did not differ between responders and non-responders (p > 0.05). If the cut-off for the 75th percentile was set to an AP of 37.5 mL min{sup −1} 100 mL{sup −1}, therapy response could be predicted with a sensitivity of 88 % (7/8) and specificity of 75 % (6/8).ConclusionVoxel-wise histogram analysis of pretreatment CT perfusion indicating tumor heterogeneity of HCC improves the pretreatment prediction of response to TARE.

  19. Detection of lymph node metastases in head and neck cancer: A meta-analysis comparing US, USgFNAC, CT and MR imaging

    International Nuclear Information System (INIS)

    Bondt, R.B.J. de; Nelemans, P.J.; Hofman, P.A.M.; Casselman, J.W.; Kremer, B.; Engelshoven, J.M.A. van; Beets-Tan, R.G.H.

    2007-01-01

    Purpose: To perform a meta-analysis comparing ultrasonography (US), US guided fine needle aspiration cytology (USgFNAC), computed tomography (CT), and magnetic resonance imaging (MRI) in the detection of lymph node metastases in head and neck cancer. Methods: MEDLINE, EMBASE and Cochrane databases were searched (January 1990-January 2006) for studies reporting diagnostic performances of US, USgFNAC, CT, and MRI to detect cervical lymph node metastases. Two reviewers screened text and reference lists of potentially eligible articles. Criteria for study inclusion: (1) histopathology was the reference standard, (2) primary tumors and metastases were squamous cell carcinoma and (3) data were available to construct 2 x 2 contingency tables. Meta-analysis of pairs of sensitivity and specificity was performed using bivariate analysis. Summary estimates for diagnostic performance used were sensitivity, specificity, diagnostic odds ratios (DOR) (95% confidence intervals) and summary receiver operating characteristics (SROC) curves. Results: From seventeen articles, 25 data sets could be retrieved. Eleven articles studied one modality: US (n = 4); USgFNAC (n = 1); CT (n = 3); MRI (n = 3). Six articles studied two or more modalities: US and CT (n = 2); USgFNAC and CT (n = 1); CT and MRI (n = 1); MRI and MRI-USPIO (Sinerem) (n = 2); US, USgFNAC, CT and MRI (n = 1). USgFNAC (AUC = 0.98) and US (AUC = 0.95) showed the highest areas under the curve (AUC). MRI-USPIO (AUC = 0.89) and CT (AUC = 0.88) had similar results. MRI showed an AUC = 0.79. USgFNAC showed the highest DOR (DOR = 260) compared to US (DOR = 40), MRI-USPIO (DOR = 21), CT (DOR = 14) and MRI (DOR = 7). Conclusion USgFNAC showed to be the most accurate imaging modality to detect cervical lymph node metastases

  20. Analysis of the proportion of the patients referred to PET/CT in some areas of China

    International Nuclear Information System (INIS)

    Yao Zhiming; Qu Wanying; Zheng Jianguo; Lin Jiabing; Wang Mei; Luo Zhifu; Guan Yihui; Wang Quanshi; Chen Qiusong; Zhang Yongxue; Huang Qingjuan; Yin Jilin; Li Yaming; Liu Qingwei; Guo Wanhua

    2008-01-01

    Objective: The aim of this study was to analyze the current practical status of PET/CT application in China and for provision of data in support of promoting the utility of this imaging modality. Methods: All 3018 PET/CT cases from 10 hospitals in the top 3 rankings were recruited in the data analysis from June to August, 2006. Results: (1) Reason for referral: the proportions of patients referred for onco- logic diagnosis, check-up and other reasons were 63.0%, 32.9% and 4.1%, respectively. (2) Diagnosis: PET/CT had a 93.5% true positive value in diagnosing malignant tumors, 38.6% success rate in identifying the primary malignancy in patients presented with metastases, and 23.3% discovery rate of malignancy in patients with space-occupying lesions pathologically diagnosed as benign but clinically requested to differentiate between benignity and malignancy. (3) Patient data: the proportion of patients in the top 3 income groups (monthly) was: > RMB 6000, 30.4%; RMB 4001-6000, 28.8%; and RMB 2001-4000, 18.6%. The proportion of patients in the top 3 medical insurance or security category: self-paid or uninsured, 55.6%; national basic insurance scheme, 26.5%; public paid fund, 11.4%. The top 3 groups of patients categorized according to profession were: departmental officials, 21.9%; retiree, 15.6%; company leaders, 11.8%. The top 3 groups according to level of education were: university (including college), 48.2%; high school (including technical training schools), 21.3%; primary school, 13.8%. Conclusions: PET/ CT holds an essential clinical value in oncology. It is an utmost issue on how to fully utilize the existing resources with a purpose to achieve maximal benefit and return. (authors)

  1. Tumor and normal tissue motion in the thorax during respiration: Analysis of volumetric and positional variations using 4D CT

    International Nuclear Information System (INIS)

    Weiss, Elisabeth; Wijesooriya, Krishni; Dill, S. Vaughn; Keall, Paul J.

    2007-01-01

    Purpose: To investigate temporospatial variations of tumor and normal tissue during respiration in lung cancer patients. Methods and Materials: In 14 patients, gross tumor volume (GTV) and normal tissue structures were manually contoured on four-dimensional computed tomography (4D-CT) scans. Structures were evaluated for volume changes, centroid (center of mass) motion, and phase dependence of variations relative to inspiration. Only volumetrically complete structures were used for analysis (lung in 2, heart in 8, all other structures in >10 patients). Results: During respiration, the magnitude of contoured volumes varied up to 62.5% for GTVs, 25.5% for lungs, and 12.6% for hearts. The range of maximum three-dimensional centroid movement for individual patients was 1.3-24.0 mm for GTV, 2.4-7.9 mm for heart, 5.2-12.0 mm for lungs, 0.3-5.5 mm for skin markers, 2.9-10.0 mm for trachea, and 6.6-21.7 mm for diaphragm. During respiration, the centroid positions of normal structures varied relative to the centroid position of the respective GTV by 1.5-8.1 mm for heart, 2.9-9.3 mm for lungs, 1.2-9.2 mm for skin markers, 0.9-7.1 mm for trachea, and 2.7-16.4 mm for diaphragm. Conclusion: Using 4D-CT, volumetric changes, positional alterations as well as changes in the position of contoured structures relative to the GTV were observed with large variations between individual patients. Although the interpretation of 4D-CT data has considerable uncertainty because of 4D-CT artifacts, observer variations, and the limited acquisition time, the findings might have a significant impact on treatment planning

  2. Single source dual energy CT: What is the optimal monochromatic energy level for the analysis of the lung parenchyma?

    Energy Technology Data Exchange (ETDEWEB)

    Ohana, M., E-mail: mickael.ohana@gmail.com [iCube Laboratory, Université de Strasbourg/CNRS, UMR 7357, 67400 Illkirch (France); Service de Radiologie B, Nouvel Hôpital Civil – Hôpitaux Universitaires de Strasbourg, 1 place de l’hôpital, 67000 Strasbourg (France); Labani, A., E-mail: aissam.labani@chru-strasbourg.fr [Service de Radiologie B, Nouvel Hôpital Civil – Hôpitaux Universitaires de Strasbourg, 1 place de l’hôpital, 67000 Strasbourg (France); Severac, F., E-mail: francois.severac@chru-strasbourg.fr [Département de Biostatistiques et d’Informatique Médicale, Hôpital Civil – Hôpitaux Universitaires de Strasbourg,1 place de l’hôpital, 67000 Strasbourg (France); Jeung, M.Y., E-mail: Mi-Young.Jeung@chru-strasbourg.fr [Service de Radiologie B, Nouvel Hôpital Civil – Hôpitaux Universitaires de Strasbourg, 1 place de l’hôpital, 67000 Strasbourg (France); Gaertner, S., E-mail: Sebastien.Gaertner@chru-strasbourg.fr [Service de Médecine Vasculaire, Nouvel Hôpital Civil – Hôpitaux Universitaires de Strasbourg,1 place de l’hôpital, 67000 Strasbourg (France); and others

    2017-03-15

    Highlights: • Lung parenchyma aspect varies with the monochromatic energy level in spectral CT. • Optimal diagnostic and image quality is obtained at 50–55 keV. • Mediastinum and parenchyma could be read on the same monochromatic energy level. - Abstract: Objective: To determine the optimal monochromatic energy level for lung parenchyma analysis in spectral CT. Methods: All 50 examinations (58% men, 64.8 ± 16yo) from an IRB-approved prospective study on single-source dual energy chest CT were retrospectively included and analyzed. Monochromatic images in lung window reconstructed every 5 keV from 40 to 140 keV were independently assessed by two chest radiologists. Based on the overall image quality and the depiction/conspicuity of parenchymal lesions, each reader had to designate for every patient the keV level providing the best diagnostic and image quality. Results: 72% of the examinations exhibited parenchymal lesions. Reader 1 picked the 55 keV monochromatic reconstruction in 52% of cases, 50 in 30% and 60 in 18%. Reader 2 chose 50 keV in 52% cases, 55 in 40%, 60 in 6% and 40 in 2%. The 50 and 55 keV levels were chosen by at least one reader in 64% and 76% of all patients, respectively. Merging 50 and 55 keV into one category results in an optimal setting selected by reader 1 in 82% of patients and by reader 2 in 92%, with a 74% concomitant agreement. Conclusion: The best image quality for lung parenchyma in spectral CT is obtained with the 50–55 keV monochromatic reconstructions.

  3. Diagnostic value of CT-colonography as compared to colonoscopy in an asymptomatic screening population: a meta-analysis

    International Nuclear Information System (INIS)

    Haan, Margriet C. de; Gelder, Rogier E. van; Bipat, Shandra; Stoker, Jaap; Graser, Anno

    2011-01-01

    Previous meta-analyses on CT-colonography included both average and high risk individuals, which may overestimate the diagnostic value in screening. A meta-analysis was performed to obtain the value of CT-colonography for screening. A search was performed using PubMed, Embase and Cochrane. Article selection and critical appraisal was done by two reviewers. Inclusion criteria: prospective, randomized trials or cohort studies comparing CT-colonography with colonoscopy (≥50 participants), ≥95% average risk participants ≥50 years. Study characteristics and 2 x 2 contingency Tables were recorded. Sensitivity and specificity estimates were calculated per patient and per polyp (≥6 mm, ≥10 mm), using univariate and bivariate analyses. Five of 1,021 studies identified were included, including 4,086 participants ( 2 -values showed substantial heterogeneity, especially for 6-9 mm polyps and adenomas: 68.1% vs. 78.6% (sensitivity per patient). Estimated sensitivities for patients with polyps or adenomas ≥ 6 mm were 75.9% and 82.9%, corresponding specificities 94.6% and 91.4%. Estimated sensitivities for patients with polyps or adenomas ≥ 10 mm were 83.3% and 87.9%, corresponding specificities 98.7% and 97.6%. Estimated sensitivities per polyp for advanced adenomas ≥ 6 mm and ≥ 10 mm were 83.9% and 83.8%. Compared to colonoscopy, CT-colonography has a high sensitivity for adenomas ≥ 10 mm. For (advanced) adenomas ≥ 6 mm sensitivity is somewhat lower. (orig.)

  4. New approach to detect and classify stroke in skull CT images via analysis of brain tissue densities.

    Science.gov (United States)

    Rebouças Filho, Pedro P; Sarmento, Róger Moura; Holanda, Gabriel Bandeira; de Alencar Lima, Daniel

    2017-09-01

    Cerebral vascular accident (CVA), also known as stroke, is an important health problem worldwide and it affects 16 million people worldwide every year. About 30% of those that have a stroke die and 40% remain with serious physical limitations. However, recovery in the damaged region is possible if treatment is performed immediately. In the case of a stroke, Computed Tomography (CT) is the most appropriate technique to confirm the occurrence and to investigate its extent and severity. Stroke is an emergency problem for which early identification and measures are difficult; however, computer-aided diagnoses (CAD) can play an important role in obtaining information imperceptible to the human eye. Thus, this work proposes a new method for extracting features based on radiological density patterns of the brain, called Analysis of Brain Tissue Density (ABTD). The proposed method is a specific approach applied to CT images to identify and classify the occurrence of stroke diseases. The evaluation of the results of the ABTD extractor proposed in this paper were compared with extractors already established in the literature, such as features from Gray-Level Co-Occurrence Matrix (GLCM), Local binary patterns (LBP), Central Moments (CM), Statistical Moments (SM), Hu's Moment (HM) and Zernike's Moments (ZM). Using a database of 420 CT images of the skull, each extractor was applied with the classifiers such as MLP, SVM, kNN, OPF and Bayesian to classify if a CT image represented a healthy brain or one with an ischemic or hemorrhagic stroke. ABTD had the shortest extraction time and the highest average accuracy (99.30%) when combined with OPF using the Euclidean distance. Also, the average accuracy values for all classifiers were higher than 95%. The relevance of the results demonstrated that the ABTD method is a useful algorithm to extract features that can potentially be integrated with CAD systems to assist in stroke diagnosis. Copyright © 2017 Elsevier B.V. All rights

  5. Analysis of the static pressure volume curve of the lung in experimentally induced pulmonary damage by CT-densitometry

    International Nuclear Information System (INIS)

    David, M.; Karmrodt, J.; Herwelling, A.; Bletz, C.; David, S.; Heussel, C.P.; Markstaller, K.

    2005-01-01

    Purpose: To study quantitative changes of lung density distributions when recording in- and expiratory static pressure-volume curves by single slice computed tomography (CT). Materials and Methods: Static in- and expiratory pressure volume curves (0 to 1000 ml, increments of 100 ml) were obtained in random order in 10 pigs after induction of lung damage by saline lavage. Simultaneously, CT acquisitions (slice thickness 1 mm, temporal increment 2 s) were performed in a single slice (3 cm below the carina). In each CT image lung segmentation and planimetry of defined density ranges were achieved. The lung density ranges were defined as: hyperinflated (-1024 to -910 HU), normal aerated (-910 to -600 HU), poorly aerated (-600 to -300 HU), and non aerated (-300 to 200 HU) lung. Fractional areas of defined density ranges in percentage of total lung area were compared to recorded volume increments and airway pressures (atmospheric pressure, lower inflection point (LIP), LIP*0.5, LIP*1.5, peak airway pressure) of in- and expiratory pressure-volume curves. Results: Quantitative analysis of defined density ranges showed no differences between in- and expiratory pressure-volume curves. The amount of poorly aerated lung decreased and normal aerated lung increased constantly when airway pressure and volume were increased during inspiratory pressure-volume curves and vice versa during expiratory pressure-volume loops. Conclusion: Recruitment and derecruitment of lung atelectasis during registration of static in- and expiratory pressure-volume loops occurred constantly, but not in a stepwise manner. CT was shown to be an appropriate method to analyse these recruitment process. (orig.)

  6. Diagnosing and quantification of acute alcohol intoxication. Comparison of dual-energy CT with biochemical analysis. Initial experience

    International Nuclear Information System (INIS)

    Korkusuz, H.; Abbas Raschidi, B.; Keese, D.; Kromen, W.; Bauer, R.W.; Vogl, T.J.; Namgaladze, D.

    2012-01-01

    Purpose: To quantify the correlation between fat content of an acute alcohol intoxication and the difference of computer tomography attenuation value in dual-energy CT in comparison to biochemical triglyceride analysis and to evaluate qualitatively the value of DECT in the diagnosis of fatty liver caused by ethanol-dosage in rats. Materials and Methods: DECT at 140 kV and 80 kV was performed on 20 rats before and two days after the administration of 3 ml of 50 % ethanol. The CT attenuation value in the livers at 140 kV, 80 kV and the differences between them in Hounsfield units (ΔH) were collected. Parts of the liver (100 mg) were measured in biochemical triglyceride analysis as the reference standard. A blood sample was also taken to measure specific liver enzymes. Results: Linear correlation between biochemical triglyceride analysis and CT density of ΔH was found (r = 0.949). 140 kV attenuation data were between 44 HU and 61.3 HU, 80 kV attenuation data were between 58.4 HU and 64.7 HU, and ΔH data were between 3.4 HU and 14.4 HU (p ≤ 0.037). The biochemical triglyceride analysis data were between 7.1 mg/g and 41.1 mg/g. The hepatic enzymes serum aspartate (ASAT) aminotransferase and alanine aminotransferase (ALAT) were elevated in all rats. ASAT correlated directly with ΔHU (r = -0.86). Conclusion: DECT provides a non-invasive method to determine and evaluate hepatic fat content after acute alcohol intoxication. It provides the possibility to detect and quantify the hepatic fat content of liver graft. (orig.)

  7. Multi-level tree analysis of pulmonary artery/vein trees in non-contrast CT images

    Science.gov (United States)

    Gao, Zhiyun; Grout, Randall W.; Hoffman, Eric A.; Saha, Punam K.

    2012-02-01

    Diseases like pulmonary embolism and pulmonary hypertension are associated with vascular dystrophy. Identifying such pulmonary artery/vein (A/V) tree dystrophy in terms of quantitative measures via CT imaging significantly facilitates early detection of disease or a treatment monitoring process. A tree structure, consisting of nodes and connected arcs, linked to the volumetric representation allows multi-level geometric and volumetric analysis of A/V trees. Here, a new theory and method is presented to generate multi-level A/V tree representation of volumetric data and to compute quantitative measures of A/V tree geometry and topology at various tree hierarchies. The new method is primarily designed on arc skeleton computation followed by a tree construction based topologic and geometric analysis of the skeleton. The method starts with a volumetric A/V representation as input and generates its topologic and multi-level volumetric tree representations long with different multi-level morphometric measures. A new recursive merging and pruning algorithms are introduced to detect bad junctions and noisy branches often associated with digital geometric and topologic analysis. Also, a new notion of shortest axial path is introduced to improve the skeletal arc joining two junctions. The accuracy of the multi-level tree analysis algorithm has been evaluated using computer generated phantoms and pulmonary CT images of a pig vessel cast phantom while the reproducibility of method is evaluated using multi-user A/V separation of in vivo contrast-enhanced CT images of a pig lung at different respiratory volumes.

  8. Assessment of aortitis by semiquantitative analysis of 180-min {sup 18}F-FDG PET/CT acquisition images

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Rodriguez, Isabel [University of Cantabria, Department of Nuclear Medicine, Marques de Valdecilla University Hospital, Santander (Spain); Hospital Universitario Marques de Valdecilla, S. Medicina Nuclear, Santander (Spain); Martinez-Amador, N.; Banzo, I.; Quirce, R.; Jimenez-Bonilla, J.; Arcocha-Torres, M. de; Ibanez-Bravo, S.; Lavado-Perez, C.; Bravo-Ferrer, Z.; Carril, J.M. [University of Cantabria, Department of Nuclear Medicine, Marques de Valdecilla University Hospital, Santander (Spain); Blanco, R.; Gonzalez-Gay, M.A. [University of Cantabria, Department of Rheumatology, Marques de Valdecilla University Hospital, Santander (Spain)

    2014-12-15

    The aim of this study was to evaluate the contribution of semiquantitative analysis of 180-min {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT images for the assessment of aortitis in cases of suspected large vessel vasculitis (LVV) and to establish a threshold index for application in the clinical setting. This prospective study included 43 patients (mean age 67.5 ± 12.9 years) with suspicion of LVV (25 with a final diagnosis of aortitis). {sup 18}F-FDG PET/CT scan was acquired 180 min after injection of 7 MBq/kg of {sup 18}F-FDG. A semiquantitative analysis was performed calculating the aortic wall maximum standardized uptake value (SUV{sub max}) (T), the lumen SUV{sub max} (B) and the target to background ratio (TBR). These results were also compared with those obtained in a control population. The mean aortic wall SUV{sub max} was 2.00 ± 0.62 for patients with aortitis and 1.45 ± 0.31 for patients without aortitis (p < 0.0001). The TBR was 1.66 ± 0.26 for patients with aortitis and 1.24 ± 0.08 for patients without aortitis (p < 0.0001). The differences were also statistically significant when the patients with aortitis and controls were compared. Receiver-operating characteristic (ROC) analysis revealed that the area under the curve was greater for the TBR than for the aortic wall SUV{sub max} (0.997 vs 0.871). The highest sensitivity and specificity was obtained for a TBR of 1.34 (sensitivity 100 %, specificity 94.4 %). Semiquantitative analysis of PET/CT images acquired 180 min after {sup 18}F-FDG injection and the TBR index of 1.34 show very high accuracy and, therefore, are strongly recommended for the diagnosis of aortitis in the clinical setting. (orig.)

  9. CT simulation in stereotactic brain radiotherapy - analysis of isocenter reproducibility with mask fixation

    International Nuclear Information System (INIS)

    Willner, Jochen; Flentje, Michael; Bratengeier, Klaus

    1997-01-01

    Background and purpose: CT verification and measurement of isocenter deviation using repeated mask fixation in linac-based stereotactic high dose radiotherapy of brain metastases were performed in this study. Materials and methods: For stereotactic radiotherapy of brain metastases a commercial head mask fixation device based on thermoplastic materials (BrainLAB) was used. A two-step planning-treatment procedure was performed. Immediately before treatment the patient was relocated in the mask and a verification CT scan of the radiopaque marked isocenter was performed and if necessary its position was corrected. The verification procedure is described in detail. Twenty-two CT verifications in 16 patients were analyzed. Deviations were measured separately for each direction. A 3D-deviation vector was calculated. Additionally the average amount of deviation in each of the three dimensions was calculated. Results: The mean deviation and standard deviation (SD) of the isocenter was 0.4 mm (SD 1.5 mm) in the longitudinal direction, -0.1 mm (SD 1.8 mm) in the lateral direction and 0.1 mm (SD 1.2 mm) in the anterior-posterior direction. The mean three-dimensional distance (3D-vector) between the verified and the corrected isocenter was 2.4 mm (SD 1.3 mm). The average deviation (without consideration of direction) was 1.1 mm (SD 1.1 mm), 1.3 mm (SD 1.3 mm) and 0.8 mm (SD 0.9 mm) in the longitudinal, lateral and sagittal directions, respectively. No correlation was found between 3D-deviation and the distance of the isocenter from the reference plane nor between deviation and the position of metastases in the brain (central versus peripheral or between different lobes), or the date of treatment. Conclusion: Reproducibility of the isocenter using the presented mask fixation is in the range of positioning reproducibility reported for other non-invasive fixation devices for stereotactic brain treatment. Our results underline the importance of CT verification as a quality

  10. Design and implementation of a 3D-MR/CT geometric image distortion phantom/analysis system for stereotactic radiosurgery

    Science.gov (United States)

    Damyanovich, A. Z.; Rieker, M.; Zhang, B.; Bissonnette, J.-P.; Jaffray, D. A.

    2018-04-01

    The design, construction and application of a multimodality, 3D magnetic resonance/computed tomography (MR/CT) image distortion phantom and analysis system for stereotactic radiosurgery (SRS) is presented. The phantom is characterized by (1) a 1 × 1 × 1 (cm)3 MRI/CT-visible 3D-Cartesian grid; (2) 2002 grid vertices that are 3D-intersections of MR-/CT-visible ‘lines’ in all three orthogonal planes; (3) a 3D-grid that is MR-signal positive/CT-signal negative; (4) a vertex distribution sufficiently ‘dense’ to characterize geometrical parameters properly, and (5) a grid/vertex resolution consistent with SRS localization accuracy. When positioned correctly, successive 3D-vertex planes along any orthogonal axis of the phantom appear as 1 × 1 (cm)2-2D grids, whereas between vertex planes, images are defined by 1 × 1 (cm)2-2D arrays of signal points. Image distortion is evaluated using a centroid algorithm that automatically identifies the center of each 3D-intersection and then calculates the deviations dx, dy, dz and dr for each vertex point; the results are presented as a color-coded 2D or 3D distribution of deviations. The phantom components and 3D-grid are machined to sub-millimeter accuracy, making the device uniquely suited to SRS applications; as such, we present it here in a form adapted for use with a Leksell stereotactic frame. Imaging reproducibility was assessed via repeated phantom imaging across ten back-to-back scans; 80%–90% of the differences in vertex deviations dx, dy, dz and dr between successive 3 T MRI scans were found to be  ⩽0.05 mm for both axial and coronal acquisitions, and over  >95% of the differences were observed to be  ⩽0.05 mm for repeated CT scans, clearly demonstrating excellent reproducibility. Applications of the 3D-phantom/analysis system are presented, using a 32-month time-course assessment of image distortion/gradient stability and statistical control chart for 1.5 T and 3 T GE TwinSpeed MRI

  11. The diagnostic performance of CT-derived fractional flow reserve for evaluation of myocardial ischaemia confirmed by invasive fractional flow reserve: a meta-analysis

    International Nuclear Information System (INIS)

    Li, S.; Tang, X.; Peng, L.; Luo, Y.; Dong, R.; Liu, J.

    2015-01-01

    Aim: To review the literature on the diagnostic accuracy of CT-derived fractional flow reserve (FFR CT ) for the evaluation of myocardial ischaemia in patients with suspected or known coronary artery disease, with invasive fractional flow reserve (FFR) as the reference standard. Materials and methods: A PubMed, EMBASE, and Cochrane cross-search was performed. The pooled diagnostic accuracy of FFR CT , with FFR as the reference standard, was primarily analysed, and then compared with that of CT angiography (CTA). The thresholds to diagnose ischaemia were FFR ≤0.80 or CTA ≥50% stenosis. Data extraction, synthesis, and statistical analysis were performed by standard meta-analysis methods. Results: Three multicentre studies (NXT Trial, DISCOVER-FLOW study and DeFACTO study) were included, examining 609 patients and 1050 vessels. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), negative likelihood ratio (LR−), and diagnostic odds ratio (DOR) for FFR CT were 89% (85–93%), 71% (65–75%), 70% (65–75%), 90% (85–93%), 3.31 (1.79–6.14), 0.16 (0.11–0.23), and 21.21 (9.15–49.15) at the patient-level, and 83% (78–63%), 78% (75–81%), 61% (56–65%), 92% (89–90%), 4.02 (1.84–8.80), 0.22 (0.13–0.35), and 19.15 (5.73–63.93) at the vessel-level. At per-patient analysis, FFR CT has similar sensitivity but improved specificity, PPV, NPV, LR+, LR−, and DOR versus those of CTA. At per-vessel analysis, FFR CT had a slightly lower sensitivity, similar NPV, but improved specificity, PPV, LR+, LR−, and DOR compared with those of CTA. The area under the summary receiver operating characteristic curves for FFR CT was 0.8909 at patient-level and 0.8865 at vessel-level, versus 0.7402 for CTA at patient-level. Conclusions: FFR CT , which was associated with improved diagnostic accuracy versus CTA, is a viable alternative to FFR for detecting coronary ischaemic lesions

  12. Multi-detector CT-colonography in inflammatory bowel disease: Prospective analysis of CT-findings to high-resolution video colonoscopy

    International Nuclear Information System (INIS)

    Andersen, Kjel; Vogt, Christoph; Blondin, Dirk; Beck, Andreas; Heinen, Wolfram; Aurich, Volker; Haeussinger, Dieter; Moedder, Ulrich; Cohnen, Mathias

    2006-01-01

    Aim: Prospective analysis of multi-detector CT-colonography (MDCTC) in patients with inflammatory bowel disease (IBD) compared to high-resolution video-endoscopy (HRVC). Materials and methods: Twenty-one patients (mean age 49.6 years) with Crohn's disease or ulcerative colitis underwent MDCTC (Somatom Volume Zoom, Siemens, Erlangen; 1 mm collimation, Pitch 8, 100 mAs, 120 kVp). HRVC was performed within 2 h after MDCTC. MDCTC was analyzed by two blinded readers. MDCTC-findings including bowel wall alterations and extraintestinal changes were compared to results of HRVC. Results: Over-all-sensitivity was 100% for endoluminal lesions with correct diagnosis of two cancers. Acute and chronic IBD were correctly identified by MDCTC in 63.6%, and 100%, respectively, with a specificity of 75%, and 100%. Sensitivity, specificity, positive and negative predictive values of MDCTC for diagnosis of acute and chronic disease were best for chronic disease. Sensitivity was worst for acute ulcerative colitis and specificity was worst for acute Crohn's disease. Haustral loss was seen only in ulcerative colitis. Pseudopolyps and fistulae were findings exclusive to Crohn's disease. Particularly extraintestinal findings as increased vascularization and local lymphadenopathy correlated well with endoscopic definition of acute disease. Because of the possibly more vulnerable colonic wall in acute inflammatory bowel disease, the air inflation for MDCTC should be performed most carefully to avoid any risk of colonic perforation. Conclusion: MDCTC may help to distinguish between patients with acute and chronic IBD. Especially extraintestinal complications, tumorous as well as pseudo-tumorous lesions can be detected with high sensitivity and specificity

  13. In vivo volumetric analysis of tumours by CT: What is the value of the calculation of tumour volumes for recurrent rectal cancer?

    International Nuclear Information System (INIS)

    Aydin, H.; Richter, E.; Feyerabend, T.; Bohndorf, W.

    1990-01-01

    The volumetric analysis of a tumour by CT is a reliable and clinically important method of examination which is rarely used. As for oncology, the importance of this method is based upon the determination of the stage of remission posttherapeutically, especially in those cases which respond to therapy without a roentgenologic change in comparison to pretherapeutic findings. This applies in particular for the evaluation of CT images. In this study 115 CT examinations of 38 patients with recurrent rectal cancer were evaluated and the tumour remission was measured by an exact determination of the tumour volume before and after radiotherapy. The results were compared with the CT findings without volumetric analysis. A change of the tumour size up to 20% of the pretherapeutic volume which eludes from the visual perception can be revealed by a subtle CT-assisted volumetric analysis. Formulas for calculation of the volume or the data concerning length, width and depth of a mass prove to be insufficient or incorrect. Therefore the correct evaluation of a tumour regression or progression shoud be done more often by CT-assisted volumetric analysis. (orig.) [de

  14. Analysis of the enamel hypoplasia using micro-CT scanner versus classical method.

    Science.gov (United States)

    Marchewka, Justyna; Skrzat, Janusz; Wróbel, Andrzej

    2014-01-01

    This article demonstrates the use of micro-CT scanning of the teeth surface for recognizing and evaluating severity of the enamel hypoplasia. To test capabilities of the microtomography versus classical method of evaluation hypoplastic defects of the enamel we selected two human teeth (C, M(2)) showing different types of enamel hypoplasia: linear, pits, and groove. Examined samples derive from archeological material dated on XVII-XVIII AD and excavated in Poland. In the current study we proved that micro-CT scanning is a powerful technique not only for imaging all kinds of the enamel hypoplasia but also allows to perform accurate measurements of the enamel defects. We figure out that contrary to the classical method of scoring enamel defects, the micro-computed tomography yields adequate data which serve for estimating the length of stress episode and length of interval between them.

  15. Automatic airway-artery analysis on lung CT to quantify airway wall thickening and bronchiectasis

    DEFF Research Database (Denmark)

    Perez-Rovira, Adria; Kuo, Wieying; Petersen, Jens

    2016-01-01

    Purpose: Bronchiectasis and airway wall thickening are commonly assessed in computed tomography (CT) by comparing the airway size with the size of the accompanying artery. Thus, in order to automate the quantification of bronchiectasis and wall thickening following a similar principle......, and pairs airway branches with the accompanying artery, then quantifies airway wall thickening and bronchiectasis by measuring the wall-artery ratio (WAR) and lumen and outer wall airway-artery ratio (AAR). Measurements that do not use the artery size for normalization are also extracted, including wall...... area percentage (WAP), wall thickness ratio (WTR), and airway diameters. Results: The method was thoroughly evaluated using 8000 manual annotations of airway-artery pairs from 24 full-inspiration pediatric CT scans (12 diseased and 12 controls). Limits of agreement between the automatically...

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

    International Nuclear Information System (INIS)

    Suzuki, Naoki; Hamada, Takashi.

    1990-01-01

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

  17. THORACIC COMPLICATIONS OF OESOPHAGEAL CARCINOMA- A RETROSPECTIVE ANALYSIS OF CT APPEARANCES

    Directory of Open Access Journals (Sweden)

    Piyush Joshi

    2017-07-01

    Full Text Available BACKGROUND Oesophageal cancer is a common gastrointestinal tract malignancy and Computed Tomography (CT is generally used for its initial evaluation and staging. Due to the anatomical relationships of the oesophagus, malignancies afflicting it can also give rise to various pulmonary and thoracic complications. The staging CT can also be used to detect and evaluate these complications. Detection of concurrent thoracic complications in addition to the primary malignancy is imperative to institute appropriate management. The aim of the study is to analyse and discuss the various thoracic complications in cases of oesophageal carcinoma detected on Multidetector Computed Tomography (MDCT. MATERIALS AND METHODS MDCT images of 27 cases of histopathologically-proven carcinoma oesophagus who had thoracic complications in addition to features of malignancy and metastases were retrospectively analysed. The various pulmonary and thoracic complications in addition to the primary lesions were assessed and evaluated. RESULTS There were 27 cases of oesophageal carcinoma with complications, of which there were 20 patients who had pulmonary consolidation/pneumonitis, 5 had oesophago-respiratory fistulae, 1 had a lung abscess, 2 had pericardial effusions, 3 had pleural effusions, 2 cases of airway compromise with atelectasis and 2 cases with Pulmonary Thromboembolism (PTE. CONCLUSION The routine chest CT for evaluation and staging of the primary tumour in cases of oesophageal carcinoma can also reveal thoracic complications directly or indirectly related the cancer some of which may alter management. The most common of these are pneumonia and oesophago-respiratory fistulas. Others like pulmonary thromboembolism may require immediate intervention. An awareness of the spectrum of imaging appearances of these complications and due vigilance while interpreting chest CT studies will aid decision making and institution of appropriate management.

  18. Analysis of clinical value of CT in the diagnosis of pediatric pneumonia and mycoplasma pneumonia

    OpenAIRE

    GONG, LIANG; ZHANG, CHONG-LIN; ZHEN, QING

    2016-01-01

    Pneumonia is an infectious disease of the lung causing mortality. Mycoplasma pneumonia (MP) is an atypical bacterial pneumonia that damages several organs. Lung computed tomography (CT) has been utilized in its identification. The aim of the present study was to examine the value of computed tomography diagnosis for pediatric MP. The present study prospectively analyzed the clinical and imaging data of 1,280 cases of pediatric MP in the out- and inpatient departments from March, 2010 to March...

  19. Predicting Peri-Device Leakage of Left Atrial Appendage Device Closure Using Novel Three-Dimensional Geometric CT Analysis.

    Science.gov (United States)

    Chung, Hyemoon; Jeon, Byunghwan; Chang, Hyuk-Jae; Han, Dongjin; Shim, Hackjoon; Cho, In Jeong; Shim, Chi Young; Hong, Geu-Ru; Kim, Jung-Sun; Jang, Yangsoo; Chung, Namsik

    2015-12-01

    After left atrial appendage (LAA) device closure, peri-device leakage into the LAA persists due to incomplete occlusion. We hypothesized that pre-procedural three-dimensional (3D) geometric analysis of the interatrial septum (IAS) and LAA orifice can predict this leakage. We investigated the predictive parameters of LAA device closure obtained from baseline cardiac computerized tomography (CT) using a novel 3D analysis system. We conducted a retrospective study of 22 patients who underwent LAA device closure. We defined peri-device leakage as the presence of a Doppler signal inside the LAA after device deployment (group 2, n = 5) compared with patients without peri-device leakage (group 1, n = 17). Conventional parameters were measured by cardiac CT. Angles θ and φ were defined between the IAS plane and the line, linking the LAA orifice center and foramen ovale. Group 2 exhibited significantly better left atrial (LA) function than group 1 (p = 0.031). Pre-procedural θ was also larger in this group (41.9° vs. 52.3°, p = 0.019). The LAA cauliflower-type morphology was more common in group 2. Overall, the patients' LA reserve significantly decreased after the procedure (21.7 mm(3) vs. 17.8 mm(3), p = 0.035). However, we observed no significant interval changes in pre- and post-procedural values of θ and φ in either group (all p > 0.05). Angles between the IAS and LAA orifice might be a novel anatomical parameter for predicting peri-device leakage after LAA device closure. In addition, 3D CT analysis of the LA and LAA orifice could be used to identify clinically favorable candidates for LAA device closure.

  20. Comparison between manual and automated analysis for the quantification of carotid wall by using sonography. A validation study with CT

    International Nuclear Information System (INIS)

    Saba, Luca; Montisci, Roberto; Molinari, Filippo; Tallapally, Niranjan; Zeng, Guang; Mallarini, Giorgio; Suri, Jasjit S.

    2012-01-01

    Purpose: The purpose of this paper was to compare manual and automated analysis for the quantification of carotid wall obtained with sonography by using the computed tomography as validation technique. Material and methods: 21 consecutive patients underwent MDCTA and ultrasound analysis of carotid arteries (mean age 68 years; age range 59–81 years). The intima–media-thickness (IMT) of the 42 carotids was measured with novel and dedicated automated software analysis (called AtheroEdge™, Biomedical Technologies, Denver, CO, USA) and by four observers that manually calculated the IMT. The carotid artery wall thickness (CAWT) was also quantified in the CT datasets. Bland–Altman statistics was employed to measure the agreement between methods. A Student's t-test was used to test the differences between the IMT values of AtheroEdge™. The study obtained the IRB approval. Results: The correlation between automated AtheroEdge™ measurements and those of the human experts were equal to 95.5%, 73.5%, 88.9%, and 81.7%. The IMT coefficient of variation of the human experts was equal to 11.9%. By using a Student's t-test, the differences between the IMT values of AtheroEdge™ and those of the human experts were not found statistically significant (p value = 0.02). On comparing AtheroEdge™ (using Ultrasound) with CAWT (using CT), the results suggested a very good concordance of 84.96%. Conclusions: Data of this preliminary study indicate that automated software AtheroEdge™ can analyze with precision the IMT of carotid arteries and that the concordance with CT is optimal.

  1. Analysis of the acetabulum by CT scan in Japanese with osteoarthritis of the hip

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Masanori [Keio Univ., Tokyo (Japan). School of Medicine

    1997-11-01

    The morphology of the acetabulum was analyzed by CT scan in 66 Japanese patients with osteoarthritis of the hip mainly following congenital dislocation or dysplasia. The CT scan data was analyzed to standardize the pelvic inclination in all directions. In these patients, the acetabular floor had thickened and the acetabulum was located in the anterolateral portion. The bilateral difference in the acetabular anteversion angle was not different between patients and normal individuals, but the acetabular sector angle in patients was smaller than in the normal subjects. As the stage of osteoarthritis of the hip advanced, the thickness of the acetabular floor in the center and posterior portions and the anterior sector angle increased, and the lateralization of the acetabulum advanced, but the anteversion angle decreased. A bone-forming change is characteristic of the anterior acetabulum and acetabular fossa in the center and posterior portions in Japanese patients with osteoarthritis of the hip. In comparison with data obtained by standard radiography, these changes detected by CT scan corresponded to an increase of the width of a tear drop, the lateralization of the femoral head and the lack of the support of the femoral head from the acetabulum. (author)

  2. Analysis of the acetabulum by CT scan in Japanese with osteoarthritis of the hip

    International Nuclear Information System (INIS)

    Ishibashi, Masanori

    1997-01-01

    The morphology of the acetabulum was analyzed by CT scan in 66 Japanese patients with osteoarthritis of the hip mainly following congenital dislocation or dysplasia. The CT scan data was analyzed to standardize the pelvic inclination in all directions. In these patients, the acetabular floor had thickened and the acetabulum was located in the anterolateral portion. The bilateral difference in the acetabular anteversion angle was not different between patients and normal individuals, but the acetabular sector angle in patients was smaller than in the normal subjects. As the stage of osteoarthritis of the hip advanced, the thickness of the acetabular floor in the center and posterior portions and the anterior sector angle increased, and the lateralization of the acetabulum advanced, but the anteversion angle decreased. A bone-forming change is characteristic of the anterior acetabulum and acetabular fossa in the center and posterior portions in Japanese patients with osteoarthritis of the hip. In comparison with data obtained by standard radiography, these changes detected by CT scan corresponded to an increase of the width of a tear drop, the lateralization of the femoral head and the lack of the support of the femoral head from the acetabulum. (author)

  3. Micro-CT Arthrographic Analysis of Monosodium Iodoacetate- Induced Osteoarthritis in Rat Knees

    International Nuclear Information System (INIS)

    Kwon, Jong Won; Kang, Heung Sik; Hong, Sung Hwan

    2010-01-01

    To evaluate the arthrographic findings of MIA-induced osteoarthritis in rat knees using the micro-CT arthrography. Intra-articular monosodium iodoacetate (MIA) injection-induced arthritis was induced in the right knees of twelve rats; their left knees served as the control group. Eight weeks after MIA injection, micro-CT arthrography was performed on each knee. We measured the thickness of retro-patellar cartilages, the distances of tibio-femoral joint space, subchondral bone plate thickness, tibial epiphyseal height, and transverse patellar diameter. Subchondral trabecular bone indices were measured in the tibial lateral condylar epiphysis. The data were analyzed statistically using a paired t-test. The retro-patellar articular cartilage showed thinning on the right side that had been induced to develop osteoarthritis. The right knees showed a significant reduction in the distance of the tibio-femoral joint space, prominent patellar osteophytes, and the resorption of subchondral bone. Among the subchondral trabecular bone indices, percent bone volume, and trabecular thickness was reduced on the right side. The articular cartilage thickness of MIA-induced arthritis model could be measured using micro- CT arthrography. It was possible to evaluate the osteoarthritic findings including the change in subchondral bone plate thickness, osteophyte formation, and subchondral bone resorption, as well as quantitatively analyze the trabecular bone indices

  4. Micro-CT Arthrographic Analysis of Monosodium Iodoacetate- Induced Osteoarthritis in Rat Knees

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jong Won [Samsung Medical Center, Sungkyunkwan University, Seoul (Korea, Republic of); Kang, Heung Sik [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Hong, Sung Hwan [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2010-10-15

    To evaluate the arthrographic findings of MIA-induced osteoarthritis in rat knees using the micro-CT arthrography. Intra-articular monosodium iodoacetate (MIA) injection-induced arthritis was induced in the right knees of twelve rats; their left knees served as the control group. Eight weeks after MIA injection, micro-CT arthrography was performed on each knee. We measured the thickness of retro-patellar cartilages, the distances of tibio-femoral joint space, subchondral bone plate thickness, tibial epiphyseal height, and transverse patellar diameter. Subchondral trabecular bone indices were measured in the tibial lateral condylar epiphysis. The data were analyzed statistically using a paired t-test. The retro-patellar articular cartilage showed thinning on the right side that had been induced to develop osteoarthritis. The right knees showed a significant reduction in the distance of the tibio-femoral joint space, prominent patellar osteophytes, and the resorption of subchondral bone. Among the subchondral trabecular bone indices, percent bone volume, and trabecular thickness was reduced on the right side. The articular cartilage thickness of MIA-induced arthritis model could be measured using micro- CT arthrography. It was possible to evaluate the osteoarthritic findings including the change in subchondral bone plate thickness, osteophyte formation, and subchondral bone resorption, as well as quantitatively analyze the trabecular bone indices.

  5. Mechanical Property Measurements and Fracture Propagation Analysis of Longmaxi Shale by Micro-CT Uniaxial Compression

    Directory of Open Access Journals (Sweden)

    Minyue Zhou

    2018-05-01

    Full Text Available The mechanical properties and fracture propagation of Longmaxi shale loading under uniaxial compression were measured using eight cylindrical shale specimens (4 mm in diameter and 8 mm in height, with the bedding plane oriented at 0° and 90° to the axial loading direction, respectively, by micro computed tomography (micro-CT. Based on the reconstructed three-dimensional (3-D CT images of cracks, different stages of the crack growth process in the 0° and 90° orientation specimen were revealed. The initial crack generally occurred at relatively smaller loading force in the 0° bedding direction specimen, mainly in the form of tensile splitting along weak bedding planes. Shear sliding fractures were dominant in the specimens oriented at 90°, with a small number of parallel cracks occurring on the bedding plane. The average thickness and volume of cracks in the 90° specimen is higher than those for the specimen oriented at 0°. The geometrical characterization of fractures segmented from CT scan binary images shows that a specific surface area correlates with tortuosity at the different load stages of each specimen. The 3-D box-counting dimension (BCD calculations can accurately reflect crack evolution law in the shale. The results indicate that the cracks have a more complex pattern and rough surface at an orientation of 90°, due to crossed secondary cracks and shear failure.

  6. Detection and Severity Scoring of Chronic Obstructive Pulmonary Disease Using Volumetric Analysis of Lung CT Images

    International Nuclear Information System (INIS)

    Hosseini, Mohammad Parsa; Soltanian-Zadeh, Hamid; Akhlaghpoor, Shahram

    2012-01-01

    Chronic obstructive pulmonary disease (COPD) is a devastating disease.While there is no cure for COPD and the lung damage associated with this disease cannot be reversed, it is still very important to diagnose it as early as possible. In this paper, we propose a novel method based on the measurement of air trapping in the lungs from CT images to detect COPD and to evaluate its severity. Twenty-five patients and twelve normal adults were included in this study. The proposed method found volumetric changes of the lungs from inspiration to expiration. To this end, trachea CT images at full inspiration and expiration were compared and changes in the areas and volumes of the lungs between inspiration and expiration were used to define quantitative measures (features). Using these features,the subjects were classified into two groups of normal and COPD patients using a Bayesian classifier. In addition, t-tests were applied to evaluate discrimination powers of the features for this classification. For the cases studied, the proposed method estimated air trapping in the lungs from CT images without human intervention. Based on the results, a mathematical model was developed to relate variations of lung volumes to the severity of the disease. As a computer aided diagnosis (CAD) system, the proposed method may assist radiologists in the detection of COPD. It quantifies air trapping in the lungs and thus may assist them with the scoring of the disease by quantifying the severity of the disease

  7. Brain hemorrhage associated with maintenance hemodialysis. CT analysis of 19 cases

    International Nuclear Information System (INIS)

    Kawahata, Nobuya

    1994-01-01

    The CT findings of 19 hemodialyzed patients with brain hemorrhage (BH) were evaluated. The 30-day mortality rate was 78.9%. The lesion locations in the 19 cases with BH were putaminal hemorrhage in 8 patients, putaminothalamic (mixed) hemorrhage in 7, thalamic hemorrhage in one, subcortical hemorrhage in one, and cerebellar hemorrhage in one. In the remaining patient, the bleeding was confined to the ventricular system. One remarkable CT finding was the formation of a massive hematoma in most cases. In some cases, the hematoma occupied the greater part of one cerebral hemisphere. Oral anticoagulants and/or antiplatelet drugs, and intravenous heparinization could produce massive accumulations of blood in the brain parenchyma. The second major finding was the low CT absorption values of the hematoma at the acute stage, as compared to that of hypertensive BH. This decreased absorption density resulted from a low hemoglobin concentration in the hematoma itself due to the severe anemia occurring in patients on long-term maintenance hemodialysis. (author)

  8. Diagnostic accuracy of 18F-FDG-PET and PET/CT in patients with Ewing sarcoma family tumours: a systematic review and a meta-analysis

    International Nuclear Information System (INIS)

    Treglia, Giorgio; Salsano, Marco; Stefanelli, Antonella; Mattoli, Maria Vittoria; Giordano, Alessandro; Bonomo, Lorenzo

    2012-01-01

    To systematically review and meta-analyse literature data on the diagnostic performance of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) in patients with Ewing sarcoma family tumours (ESFT). PubMed/MEDLINE, Embase and Scopus databases were searched for articles that evaluated FDG-PET and PET/CT in patients with ESFT from inception to 31 May 2011. Studies that fulfilled the three following criteria were included in the systematic review: FDG-PET or PET/CT performed in patients with ESFT; articles about the diagnostic accuracy of FDG-PET and PET/CT; sample size of at least 10 patients with ESFT were included. Studies in which there were sufficient data to reassess sensitivity and specificity of FDG-PET or PET/CT in ESFT were included in the meta-analysis, excluding duplicate publications. Finally, pooled sensitivity, pooled specificity and area under the receiver operating characteristic (ROC) curve of FDG-PET or PET/CT in ESFT were calculated. We found 13 studies comprising a total of 342 patients with ESFT. The main findings of the studies included are presented. The meta-analysis of five selected studies provided these results about FDG-PET and PET/CT in ESFT: pooled sensitivity: 96% (95% confidence interval [CI] 91-99%); pooled specificity: 92% (95% CI 87-96%); area under the ROC curve: 0.97. With regard to the staging and restaging of patients with ESFT, the sensitivity, specificity and accuracy of FDG-PET and PET/CT are high; the combination of FDG-PET or PET/CT with conventional imaging is a valuable tool for the staging and restaging of ESFT and has a relevant impact on the treatment strategy plan. (orig.)

  9. Diagnostic accuracy of {sup 18}F-FDG-PET and PET/CT in patients with Ewing sarcoma family tumours: a systematic review and a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Treglia, Giorgio [Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Institute of Nuclear Medicine, Positron Emission Tomography Centre, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Salsano, Marco; Stefanelli, Antonella; Mattoli, Maria Vittoria; Giordano, Alessandro [Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Bonomo, Lorenzo [Institute of Radiology, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy)

    2012-03-15

    To systematically review and meta-analyse literature data on the diagnostic performance of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) in patients with Ewing sarcoma family tumours (ESFT). PubMed/MEDLINE, Embase and Scopus databases were searched for articles that evaluated FDG-PET and PET/CT in patients with ESFT from inception to 31 May 2011. Studies that fulfilled the three following criteria were included in the systematic review: FDG-PET or PET/CT performed in patients with ESFT; articles about the diagnostic accuracy of FDG-PET and PET/CT; sample size of at least 10 patients with ESFT were included. Studies in which there were sufficient data to reassess sensitivity and specificity of FDG-PET or PET/CT in ESFT were included in the meta-analysis, excluding duplicate publications. Finally, pooled sensitivity, pooled specificity and area under the receiver operating characteristic (ROC) curve of FDG-PET or PET/CT in ESFT were calculated. We found 13 studies comprising a total of 342 patients with ESFT. The main findings of the studies included are presented. The meta-analysis of five selected studies provided these results about FDG-PET and PET/CT in ESFT: pooled sensitivity: 96% (95% confidence interval [CI] 91-99%); pooled specificity: 92% (95% CI 87-96%); area under the ROC curve: 0.97. With regard to the staging and restaging of patients with ESFT, the sensitivity, specificity and accuracy of FDG-PET and PET/CT are high; the combination of FDG-PET or PET/CT with conventional imaging is a valuable tool for the staging and restaging of ESFT and has a relevant impact on the treatment strategy plan. (orig.)

  10. Usefulness of {sup 18}F-FDG PET, combined FDG-PET/CT and EUS in diagnosing primary pancreatic carcinoma: A meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tang Shuang [Department of Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Huang Gang, E-mail: huang2802@163.com [Department of Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Liu Jianjun [Department of Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Liu Tao [Department of Orthopedics, Soochow University, Suzhou (China); Treven, Lyndal [Faculty of Public Health, University of Sydney, Sydney (Australia); Song Saoli; Zhang Chenpeng; Pan Lingling [Department of Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Zhang Ting [Department of Anesthesiology, Renji Hospital, Shanghai (China)

    2011-04-15

    The aim was to evaluate the diagnostic value of {sup 18}F-fluorodeoxyglucose-positron emission tomography ({sup 18}F-FDG PET), combined {sup 18}F-fluorodeoxyglucose-positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) and endoscopic ultrasonography (EUS) in diagnosing patients with pancreatic carcinoma. MEDLINE, EMBASE, Cochrane library and some other databases, from January 1966 to April 2009, were searched for initial studies. All the studies published in English or Chinese relating to the diagnostic value of {sup 18}F-FDG PET, PET/CT and EUS for patients with pancreatic cancer were collected. Methodological quality was assessed. The statistic software called 'Meta-Disc 1.4' was used for data analysis. Results: 51 studies were included in this meta-analysis. The pooled sensitivity estimate for combined PET/CT (90.1%) was significantly higher than PET (88.4%) and EUS (81.2%). The pooled specificity estimate for EUS (93.2%) was significantly higher than PET (83.1%) and PET/CT (80.1%). The pooled DOR estimate for EUS (49.774) was significantly higher than PET (32.778) and PET/CT (27.105). SROC curves for PET/CT and EUS showed a little better diagnostic accuracy than PET alone. For PET alone, when interpreted the results with knowledge of other imaging tests, its sensitivity (89.4%) and specificity (80.1%) were closer to PET/CT. For EUS, its diagnostic value decreased in differentiating pancreatic cancer for patients with chronic pancreatitis. In conclusion, PET/CT was a high sensitive and EUS was a high specific modality in diagnosing patients with pancreatic cancer. PET/CT and EUS could play different roles during different conditions in diagnosing pancreatic carcinoma.

  11. SU-F-T-215: An Investigation Of Multi-Scanner CT Hounsfield Unit Calibration for Pencil Beam Scanning Proton Therapy Using 3D Gamma Analysis

    International Nuclear Information System (INIS)

    Zhang, J; Li, X; Liu, G; Liu, Q; Liang, J; Ding, X

    2016-01-01

    Purpose: We compare and investigate the dosimetric impacts on pencil beam scanning (PBS) proton treatment plans generated with CT calibration curves from four different CT scanners and one averaged ‘global’ CT calibration curve. Methods: The four CT scanners are located at three different hospital locations within the same health system. CT density calibration curves were collected from these scanners using the same CT calibration phantom and acquisition parameters. Mass density to HU value tables were then commissioned in a commercial treatment planning system. Five disease sites were chosen for dosimetric comparisons at brain, lung, head and neck, adrenal, and prostate. Three types of PBS plans were generated at each treatment site using SFUD, IMPT, and robustness optimized IMPT techniques. 3D dose differences were investigated using 3D Gamma analysis. Results: The CT calibration curves for all four scanners display very similar shapes. Large HU differences were observed at both the high HU and low HU regions of the curves. Large dose differences were generally observed at the distal edges of the beams and they are beam angle dependent. Out of the five treatment sites, lung plans exhibits the most overall range uncertainties and prostate plans have the greatest dose discrepancy. There are no significant differences between the SFUD, IMPT, and the RO-IMPT methods. 3D gamma analysis with 3%, 3 mm criteria showed all plans with greater than 95% passing rate. Two of the scanners with close HU values have negligible dose difference except for lung. Conclusion: Our study shows that there are more than 5% dosimetric differences between different CT calibration curves. PBS treatment plans generated with SFUD, IMPT, and the robustness optimized IMPT has similar sensitivity to the CT density uncertainty. More patient data and tighter gamma criteria based on structure location and size will be used for further investigation.

  12. CT-guided vertebroplasty: analysis of technical results, extraosseous cement leakages, and complications in 500 procedures

    Energy Technology Data Exchange (ETDEWEB)

    Pitton, Michael Bernhard; Herber, Sascha; Koch, Ulrike; Oberholzer, Katja; Dueber, Christoph [Johannes Gutenberg-University of Mainz, Department of Diagnostic and Interventional Radiology, Mainz (Germany); Drees, Philip [University Hospital, Johannes Gutenberg-University of Mainz, Department of Orthopedic Surgery, Mainz (Germany)

    2008-11-15

    The aim of this study was to analyze the technical results, the extraosseous cement leakages, and the complications in our first 500 vertebroplasty procedures. Patients with osteoporotic vertebral compression fractures or osteolytic lesions caused by malignant tumors were treated with CT-guided vertebroplasty. The technical results were documented with CT, and the extraosseous cement leakages and periinterventional clinical complications were analyzed as well as secondary fractures during follow-up. Since 2002, 500 vertebroplasty procedures have been performed on 251 patients (82 male, 169 female, age 71.5 {+-} 9.8 years) suffering from osteoporotic compression fractures (n = 217) and/or malignant tumour infiltration (n = 34). The number of vertebrae treated per patient was 1.96 {+-} 1.29 (range 1-10); the numbers of interventions per patient and interventions per vertebra were 1.33 {+-} 0.75 (range 1-6) and 1.01 {+-} 0.10, respectively. The amount of PMMA cement was 4.5 {+-} 1.9 ml and decreased during the 5-year period of investigation. The procedure-related 30-day mortality was 0.4% (1 of 251 patients) due to pulmonary embolism in this case. The procedure-related morbidity was 2.8% (7/251), including one acute coronary syndrome beginning 12 h after the procedure and one missing patellar reflex in a patients with a cement leak near the neuroformen because of osteolytic destruction of the respective pedicle. Additionally, one patient developed a medullary conus syndrome after a fall during the night after vertebroplasty, two patients reached an inadequate depth of conscious sedation, and two cases had additional fractures (one pedicle fracture, one rib fracture). The overall CT-based cement leak rate was 55.4% and included leakages predominantly into intervertebral disc spaces (25.2%), epidural vein plexus (16.0%), through the posterior wall (2.6%), into the neuroforamen (1.6%), into paravertebral vessels (7.2%), and combinations of these and others. During follow

  13. CT-guided vertebroplasty: analysis of technical results, extraosseous cement leakages, and complications in 500 procedures

    International Nuclear Information System (INIS)

    Pitton, Michael Bernhard; Herber, Sascha; Koch, Ulrike; Oberholzer, Katja; Dueber, Christoph; Drees, Philip

    2008-01-01

    The aim of this study was to analyze the technical results, the extraosseous cement leakages, and the complications in our first 500 vertebroplasty procedures. Patients with osteoporotic vertebral compression fractures or osteolytic lesions caused by malignant tumors were treated with CT-guided vertebroplasty. The technical results were documented with CT, and the extraosseous cement leakages and periinterventional clinical complications were analyzed as well as secondary fractures during follow-up. Since 2002, 500 vertebroplasty procedures have been performed on 251 patients (82 male, 169 female, age 71.5 ± 9.8 years) suffering from osteoporotic compression fractures (n = 217) and/or malignant tumour infiltration (n = 34). The number of vertebrae treated per patient was 1.96 ± 1.29 (range 1-10); the numbers of interventions per patient and interventions per vertebra were 1.33 ± 0.75 (range 1-6) and 1.01 ± 0.10, respectively. The amount of PMMA cement was 4.5 ± 1.9 ml and decreased during the 5-year period of investigation. The procedure-related 30-day mortality was 0.4% (1 of 251 patients) due to pulmonary embolism in this case. The procedure-related morbidity was 2.8% (7/251), including one acute coronary syndrome beginning 12 h after the procedure and one missing patellar reflex in a patients with a cement leak near the neuroformen because of osteolytic destruction of the respective pedicle. Additionally, one patient developed a medullary conus syndrome after a fall during the night after vertebroplasty, two patients reached an inadequate depth of conscious sedation, and two cases had additional fractures (one pedicle fracture, one rib fracture). The overall CT-based cement leak rate was 55.4% and included leakages predominantly into intervertebral disc spaces (25.2%), epidural vein plexus (16.0%), through the posterior wall (2.6%), into the neuroforamen (1.6%), into paravertebral vessels (7.2%), and combinations of these and others. During follow-up (15

  14. Determination of urinary stone composition using dual-energy spectral CT: Initial in vitro analysis

    International Nuclear Information System (INIS)

    Li, X.-H.; Zhao, R.; Liu, B.; Yu, Y.-Q.

    2013-01-01

    Aim: To evaluate the feasibility of determining the chemical composition of urinary stones using computed tomography (CT) spectral imaging (SI) Materials and methods: Two hundred and ten urinary stones were scanned in vitro using the SI mode and conventional polychromatic imaging (CPI; 120 kVp) mode. The radiodensity at 50 keV and 120 kVp, the mean calcium density (CD), and the water density (WD) were measured using the 50 keV images, 120 kVp images, calcium-based images, and water-based images, respectively. These parameters and the calcium–water ratio (CWR) were compared between different types of stones. CWR was defined as: CWR = ‌calcium density/water density‌. Results: According to the results determined by infrared spectroscopy, 116 pure urinary stones were divided into five groups: uric acid (UA, n = 16), struvite (STR, n = 23), cystine (CYS, n = 10), calcium phosphate (CaP, n = 29), and calcium oxalate (COX, n = 38). CD, CWR, and the radiodensity of stones at 50 keV CT imaging of each group were as follows: UA (−3.55 ± 10.85 mg/ml, 0.03 ± 0.05, 510.08 ± 157.29 HU); STR (224.99 ± 64.28 mg/ml, 0.19 ± 0.07, 1058.58 ± 260.13 HU); CYS (139.67 ± 34.66 mg/ml, 0.13 ± 0.03, 725.75 ± 142.35 HU); CaP (619.39 ± 26.13 mg/ml, 0.69 ± 0.11, 2617.46 ± 186.22 HU); COX (518.61 ± 95.5 mg/ml, 0.58 ± 0.1, 2247.47 ± 379.51 HU). The differences in the CD, CRW, and radiodensity of stones at 50 keV CT imaging among the groups were statistically significant by binary comparison (p < 0.05). There were no significant differences in the radiodensity of stones at 120 keV CT imaging between UA and CYS (p = 0.267), CaP and COX (p = 0.065), and in the WD between STR and CYS (p = 0.108). Conclusion: SI provides a novel method to better characterize pure urinary stones using the mean CD, CWR, and the radiodensity of stones at 50 keV CT imaging

  15. Focal breast lesions in clinical CT examinations of the chest. A retrospective analysis; Senologische Befunde bei CT-Untersuchungen des Thorax. Eine retrospektive Auswertung

    Energy Technology Data Exchange (ETDEWEB)

    Krug, Kathrin Barbara; Houbois, Christian; Grinstein, Olga; Borggrefe, Jan; Puesken, Michael; Maintz, David [Cologne Univ. Medical School, Cologne (Germany). Dept. of Diagnostical and Interventional Radiology; Hanstein, Bettina; Malter, Wolfram [Cologne Univ. Medical School, Cologne (Germany). Breast Center and Dept. of Obstetrics and Gynecology; Hellmich, Martin [Cologne Univ. (Germany). Inst. of Medical Statistics, Informatics and Epidemiology

    2017-10-15

    Based on radiological reports, the percentage of breast cancers visualized as incidental findings in routine CT examinations is estimated at ≤2%. In view of the rising number of CT examinations and the high prevalence of breast cancer, it was the goal of the present study to verify the frequency and image morphology of false-negative senological CT findings. All first contrast-enhanced CT examinations of the chest in adult female patients carried out in 2012 were retrospectively included. A senior radiologist systematically assessed the presence of breast lesions on all CT images using the BI-RADS system. All BI-RADS ≥3 notations were evaluated by a second senior radiologist. A consensus was obtained in case of differing BI-RADS assessments. Reference diagnoses were elaborated based on all available clinical, radiological and pathological data. The findings of the CT reports were classified according to the BI-RADS system and were compared with the retrospective consensus findings as well as with the reference diagnoses. The range of indications comprised a broad spectrum including staging and follow-up examinations of solid tumors/lymphoma (N = 701, 59.9 %) and vascular (190, 16.2 %), inflammatory (48, 4.1 %) and pulmonologic (22, 1.9 %) issues. BI-RADS 1/2 classifications were present in 92.5 % and BI-RADS 6 classifications were assessed in 1.7 % of the 1170 included examinations. 68 patients (5.8 %) had at least one lesion retrospectively classified as BI-RADS 3 - 5. The histological potential was known in 57 of these lesions as benign (46, 3.9 %) or malignant (11, 0.9 %). 13 BI-RADS 4/5 consensus assessments (1.1 %) were false-positive. 2 of the 10 lesions classified as being malignant based on the further clinical and radiological course were not mentioned in the written CT reports (0.2 %). Both false-negative CT reports were therapeutically and prognostically irrelevant. The relative frequency of BI-RADS 3 - 5 findings was 5.8 %. It reflects the situation

  16. A Comparative Analysis of the Supernova Legacy Survey Sample With ΛCDM and the Rh=ct Universe

    Science.gov (United States)

    Wei, Jun-Jie; Wu, Xue-Feng; Melia, Fulvio; Maier, Robert S.

    2015-03-01

    The use of Type Ia supernovae (SNe Ia) has thus far produced the most reliable measurement of the expansion history of the universe, suggesting that ΛCDM offers the best explanation for the redshift-luminosity distribution observed in these events. However, analysis of other kinds of sources, such as cosmic chronometers, gamma-ray bursts, and high-z quasars, conflicts with this conclusion, indicating instead that the constant expansion rate implied by the Rh = ct universe is a better fit to the data. The central difficulty with the use of SNe Ia as standard candles is that one must optimize three or four nuisance parameters characterizing supernova (SN) luminosities simultaneously with the parameters of an expansion model. Hence, in comparing competing models, one must reduce the data independently for each. We carry out such a comparison of ΛCDM and the Rh = ct universe using the SN Legacy Survey sample of 252 SN events, and show that each model fits its individually reduced data very well. However, since Rh = ct has only one free parameter (the Hubble constant), it follows from a standard model selection technique that it is to be preferred over ΛCDM, the minimalist version of which has three (the Hubble constant, the scaled matter density, and either the spatial curvature constant or the dark energy equation-of-state parameter). We estimate using the Bayes Information Criterion that in a pairwise comparison, the likelihood of Rh = ct is ˜90%, compared with only ˜10% for a minimalist form of ΛCDM, in which dark energy is simply a cosmological constant. Compared to Rh = ct, versions of the standard model with more elaborate parametrizations of dark energy are judged to be even less likely. This work is dedicated to the memory of Prof. Tan Lu, who sadly passed away 2014 December 3. Among his many achievements, he is considered to be one of the founders of high-energy astrophysics, and a pioneer in modern cosmology, in China.

  17. Diagnostic accuracy of CT in assessing extra-regional lymphadenopathy in pancreatic and peri-ampullary cancer: a systematic review and meta-analysis.

    Science.gov (United States)

    Tseng, Dorine S J; van Santvoort, Hjalmar C; Fegrachi, Samira; Besselink, Marc G; Zuithoff, Nicolaas P A; Borel Rinkes, Inne H; van Leeuwen, Maarten S; Molenaar, I Quintus

    2014-12-01

    Computed tomography (CT) is the most widely used method to assess resectability of pancreatic and peri-ampullary cancer. One of the contra-indications for curative resection is the presence of extra-regional lymph node metastases. This meta-analysis investigates the accuracy of CT in assessing extra-regional lymph node metastases in pancreatic and peri-ampullary cancer. We systematically reviewed the literature according to the PRISMA guidelines. Studies reporting on CT assessment of extra-regional lymph nodes in patients undergoing pancreatoduodenectomy were included. Data on baseline characteristics, CT-investigations and histopathological outcomes were extracted. Diagnostic accuracy, positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity were calculated for individual studies and pooled data. After screening, 4 cohort studies reporting on CT-findings and histopathological outcome in 157 patients with pancreatic or peri-ampullary cancer were included. Overall, diagnostic accuracy, specificity and NPV varied from 63 to 81, 80-100% and 67-90% respectively. However, PPV and sensitivity ranged from 0 to 100% and 0-38%. Pooled sensitivity, specificity, PPV and NPV were 25%, 86%, 28% and 84% respectively. CT has a low diagnostic accuracy in assessing extra-regional lymph node metastases in pancreatic and peri-ampullary cancer. Therefore, suspicion of extra-regional lymph node metastases on CT alone should not be considered a contra-indication for exploration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. 4D-CT Lung registration using anatomy-based multi-level multi-resolution optical flow analysis and thin-plate splines.

    Science.gov (United States)

    Min, Yugang; Neylon, John; Shah, Amish; Meeks, Sanford; Lee, Percy; Kupelian, Patrick; Santhanam, Anand P

    2014-09-01

    The accuracy of 4D-CT registration is limited by inconsistent Hounsfield unit (HU) values in the 4D-CT data from one respiratory phase to another and lower image contrast for lung substructures. This paper presents an optical flow and thin-plate spline (TPS)-based 4D-CT registration method to account for these limitations. The use of unified HU values on multiple anatomy levels (e.g., the lung contour, blood vessels, and parenchyma) accounts for registration errors by inconsistent landmark HU value. While 3D multi-resolution optical flow analysis registers each anatomical level, TPS is employed for propagating the results from one anatomical level to another ultimately leading to the 4D-CT registration. 4D-CT registration was validated using target registration error (TRE), inverse consistency error (ICE) metrics, and a statistical image comparison using Gamma criteria of 1 % intensity difference in 2 mm(3) window range. Validation results showed that the proposed method was able to register CT lung datasets with TRE and ICE values <3 mm. In addition, the average number of voxel that failed the Gamma criteria was <3 %, which supports the clinical applicability of the propose registration mechanism. The proposed 4D-CT registration computes the volumetric lung deformations within clinically viable accuracy.

  19. FDG PET and PET-CT for the detection of bone metastases in patients with head and neck cancer. A meta-analysis

    International Nuclear Information System (INIS)

    Yi, Xuelin; Zhang, Hongting; Liu, Shixi; Fan, Min; Liu, Yilin

    2013-01-01

    We performed a meta-analysis to evaluate 18FDG PET/PET-CT for the detection of bone metastases in patients with head and neck cancer. We calculated sensitivities, specificities, likelihood ratios, and constructed summary receiver operating characteristic curves for PET and PET-CT, respectively. We also compared the performance of PET/PET-CT with that of bone scintigraphy by analysing studies that had also used bone scintigraphy on the same patients. Across 9 PET studies (1621 patients) and 10 PET-CT studies (1291 patients), sensitivity and specificity of PET were 0.81 and 0.99, and of PET-CT were 0.89 and 0.99, respectively. In 5 comparative studies (1184 patients), sensitivity and specificity of PET/PET-CT were 0.85 and 0.98, and of bone scintigraphy were 0.55 and 0.98, respectively. 18FDG PET and PET-CT have high sensitivity and accuracy for the detection of bone metastasis in patients with head and neck cancer.

  20. Diagnostic performance of CT and MRI on the detection of symptomatic intracranial dural arteriovenous fistula: a meta-analysis with indirect comparison

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yen-Heng [National Taiwan University, Institute of Epidemiology and Preventive Medicine, Taipei (China); National Taiwan University Hospital in Taipei and Yuan-Lin Branch, Department of Medical Imaging and Radiology, Hospital and Medical College, Taipei (China); Lin, Hsien-Ho [National Taiwan University, Institute of Epidemiology and Preventive Medicine, Taipei (China); Liu, Hon-Man; Lee, Chung-Wei; Chen, Ya-Fang [National Taiwan University Hospital in Taipei and Yuan-Lin Branch, Department of Medical Imaging and Radiology, Hospital and Medical College, Taipei (China)

    2016-08-15

    This study aims to review the diagnostic performance of computed tomography (CT) and magnetic resonance imaging (MRI) in symptomatic dural arteriovenous fistula (DAVF). EMBASE, PubMed, and Cochrane Library were searched until April 2015 for studies which compared CT, MRI, or both with angiography for the detection of DAVF. The diagnostic performances of MRI and CT were indirectly compared using modality as a covariate in the analysis. Thirteen studies met our inclusion criteria. MRI had a sensitivity of 0.90 (95 % confidence interval (CI) = 0.83-0.94) and specificity of 0.94 (95 % CI = 0.90-0.96). CT had a sensitivity of 0.80 (95 % CI = 0.62-0.90) and specificity of 0.87 (95 % CI = 0.74-0.94). MRI showed better diagnostic performance than CT (p = 0.02). Contrast medium use and time-resolved MR angiography did not improve MRI diagnostic performance (p = 0.31 and 0.44, respectively). Both CT and MRI had good diagnostic performance. MRI was better than CT on the detection of symptomatic intracranial dural arteriovenous fistula in the indirect comparison. (orig.)

  1. Evaluation of the Cross-reactivity of Antidrug Antibodies to CT-P13 and Infliximab Reference Product (Remicade): An Analysis Using Immunoassays Tagged with Both Agents.

    Science.gov (United States)

    Reinisch, Walter; Jahnsen, Jørgen; Schreiber, Stefan; Danese, Silvio; Panés, Julián; Balsa, Alejandro; Park, Won; Kim, JiSoo; Lee, Jee Un; Yoo, Dae Hyun

    2017-06-01

    During two pivotal clinical trials of the infliximab biosimilar CT-P13 (PLANETAS and PLANETRA), antidrug antibodies (ADAs) and neutralising antibodies (NAbs) were detected in the sera of patients treated with CT-P13 and the reference product (RP; Remicade). The aim was to assess the comparability of Remicade- and CT-P13-tagged immunoassays for the detection of ADAs and NAbs using data from these trials, in order to determine the cross-reactivity of CT-P13 and RP ADAs. Sera from patients with rheumatoid arthritis and ankylosing spondylitis were analysed using an electrochemiluminescence (ECL) bridging assay or Gyros immunoassay, tagged with Remicade or CT-P13 at screening, weeks 14, 30 and 54, and the end of study visit. NAb titre was compared at screening and weeks 14 and 30. The proportion of cross-reactive samples was determined and an inter-rater agreement analysis performed to assess the concordance of results between assays. In PLANETAS, 93.1% (94/101) of RP ADA-positive samples and 93.0% (93/100) of RP NAb-positive samples cross-reacted with CT-P13; 99.0% (103/104) of CT-P13 ADA-positive and 98.0% (98/100) of CT-P13 NAb-positive samples cross-reacted with the RP. In PLANETRA, 94.7% (426/450) of RP ADA-positive samples and 94.3% (415/440) of RP NAb-positive samples cross-reacted with CT-P13, and 96.6% (458/474) of CT-P13 ADA-positive and 96.4% (452/469) of CT-P13 NAb-positive samples cross-reacted with the RP. In both studies, there was strong agreement in outcome between assays at all post-screening time points (PLANETAS: Cohen's κ 0.89-0.98 for ADA, 0.86-0.98 for NAb; PLANETRA: 0.92-0.94 for both ADA and NAb, all p PLANETAS: Spearman's ρ 0.73 and 0.74, respectively; PLANETRA: 0.61 and 0.72, respectively; all p < 0.001). This study has demonstrated that ADAs and NAbs against CT-P13 and RP are cross-reactive, indicating that CT-P13 and RP share immunodominant epitopes.

  2. The effect of spatial micro-CT image resolution and surface complexity on the morphological 3D analysis of open porous structures

    Energy Technology Data Exchange (ETDEWEB)

    Pyka, Grzegorz, E-mail: gregory.pyka@mtm.kuleuven.be [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 – PB2450, B-3001 Leuven (Belgium); Kerckhofs, Greet [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 – PB2450, B-3001 Leuven (Belgium); Biomechanics Research Unit, Université de Liege, Chemin des Chevreuils 1 - BAT 52/3, B-4000 Liège (Belgium); Schrooten, Jan; Wevers, Martine [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 – PB2450, B-3001 Leuven (Belgium)

    2014-01-15

    In material science microfocus X-ray computed tomography (micro-CT) is one of the most popular non-destructive techniques to visualise and quantify the internal structure of materials in 3D. Despite constant system improvements, state-of-the-art micro-CT images can still hold several artefacts typical for X-ray CT imaging that hinder further image-based processing, structural and quantitative analysis. For example spatial resolution is crucial for an appropriate characterisation as the voxel size essentially influences the partial volume effect. However, defining the adequate image resolution is not a trivial aspect and understanding the correlation between scan parameters like voxel size and the structural properties is crucial for comprehensive material characterisation using micro-CT. Therefore, the objective of this study was to evaluate the influence of the spatial image resolution on the micro-CT based morphological analysis of three-dimensional (3D) open porous structures with a high surface complexity. In particular the correlation between the local surface properties and the accuracy of the micro-CT-based macro-morphology of 3D open porous Ti6Al4V structures produced by selective laser melting (SLM) was targeted and revealed for rough surfaces a strong dependence of the resulting structure characteristics on the scan resolution. Reducing the surface complexity by chemical etching decreased the sensitivity of the overall morphological analysis to the spatial image resolution and increased the detection limit. This study showed that scan settings and image processing parameters need to be customized to the material properties, morphological parameters under investigation and the desired final characteristics (in relation to the intended functional use). Customization of the scan resolution can increase the reliability of the micro-CT based analysis and at the same time reduce its operating costs. - Highlights: • We examine influence of the image resolution

  3. Eight CT lessons that we learned the hard way: an analysis of current patterns of radiological error and discrepancy with particular emphasis on CT

    International Nuclear Information System (INIS)

    McCreadie, G.; Oliver, T.B.

    2009-01-01

    Aim: To review cases discussed at a radiology departmental errors and discrepancies meeting, classify these to determine common patterns of error, and, focussing on CT, present a small number of specific errors that occur commonly. Materials and methods: All cases discussed at our departmental discrepancies and complications meeting over a 30 month period were reviewed. Those where a genuine error was agreed to have arisen were classified by error type: poor image interpretation (false positive, false negative, misclassification); technical error (poor technique or procedural complication); and communications error. The imaging method from which the error arose was also recorded. Specific recurring errors were identified and collated. Results: Two hundred and fifty-six errors were identified in 222 patients. Two hundred and twenty-five errors (88%) were due to poor image interpretation (14 false positive, 155 false negative, 56 misclassification). Seven errors (3%) were technical and 24 errors (9%) were due to poor communication. One hundred and fifty-nine (62%) of the 256 errors arose in relation to CT, 31 (12%) to ultrasound, 29 (11%) to magnetic resonance imaging (MRI), 24 (9%) to radiography, and 13 (5%) to fluoroscopy examinations, three (1.2%) of which involved vascular intervention. Several repeating errors arising during CT reporting were identified. Conclusions: Error is commonly identified in relation to radiological examinations. Most errors involve image interpretation, but a significant proportion result from departmental miscommunication. The majority of errors are false-negative interpretations and occur during interpretation of CT examinations. Recurring false-negative CT errors include failure to appreciate unexpected bowel or pancreatic malignancy, incidental pulmonary emboli, abnormality of vascular structures, bone lesions, omental disease, incidental abnormality present on targeted examinations or lesions on the periphery of the field of view.

  4. Segmentation of hepatic artery in multi-phase liver CT using directional dilation and connectivity analysis

    Science.gov (United States)

    Wang, Lei; Schnurr, Alena-Kathrin; Zidowitz, Stephan; Georgii, Joachim; Zhao, Yue; Razavi, Mohammad; Schwier, Michael; Hahn, Horst K.; Hansen, Christian

    2016-03-01

    Segmentation of hepatic arteries in multi-phase computed tomography (CT) images is indispensable in liver surgery planning. During image acquisition, the hepatic artery is enhanced by the injection of contrast agent. The enhanced signals are often not stably acquired due to non-optimal contrast timing. Other vascular structure, such as hepatic vein or portal vein, can be enhanced as well in the arterial phase, which can adversely affect the segmentation results. Furthermore, the arteries might suffer from partial volume effects due to their small diameter. To overcome these difficulties, we propose a framework for robust hepatic artery segmentation requiring a minimal amount of user interaction. First, an efficient multi-scale Hessian-based vesselness filter is applied on the artery phase CT image, aiming to enhance vessel structures with specified diameter range. Second, the vesselness response is processed using a Bayesian classifier to identify the most probable vessel structures. Considering the vesselness filter normally performs not ideally on the vessel bifurcations or the segments corrupted by noise, two vessel-reconnection techniques are proposed. The first technique uses a directional morphological operator to dilate vessel segments along their centerline directions, attempting to fill the gap between broken vascular segments. The second technique analyzes the connectivity of vessel segments and reconnects disconnected segments and branches. Finally, a 3D vessel tree is reconstructed. The algorithm has been evaluated using 18 CT images of the liver. To quantitatively measure the similarities between segmented and reference vessel trees, the skeleton coverage and mean symmetric distance are calculated to quantify the agreement between reference and segmented vessel skeletons, resulting in an average of 0:55+/-0:27 and 12:7+/-7:9 mm (mean standard deviation), respectively.

  5. USE OF CT FOR ANALYSIS OF THE VERTEBRAL FORAMEN IN THE HOSPITAL OF QUERÉTARO

    Directory of Open Access Journals (Sweden)

    JESÚS CISNEROS LÁMBARRI

    Full Text Available ABSTRACT Objective: To determine the morphology of the vertebral foramen and its distance to the midline. Methods: Twenty cervical CT scans from the radiographic record of 12 men and 8 women, 18 to 74 years old, of C1 to C6 segments were evaluated, measuring the foramen diameter and its distance to the midline. We look for anomalies of vertebral foramen morphology, using Philips Ingenuity CT equipment with Philips IntelliSpace Portal software. Results: The mean age was 47 years; the segment with the most anomalies was C1, with 10% (increase in foramen diameter, followed by C2 and C6, with 5% (vertebral foramen hypotrophy; the mean diameter of the C1 to C6 segment was 6.081 mm, and the median distance from the midline to the vertebral foramen of C2 to C6 was 13.215 mm. The largest diameter of the vertebral foramen was C2, with a mean of 6.67 mm and the smallest was C4, with a mean of 5.75 mm; the greatest distance from the midline to the vertebral foramen was C1, with a mean of 22.59 mm and the shortest was C4, with a mean of 12.13 mm. Conclusions: The mean diameter of the vertebral foramen and its distance to the midline was determined, setting a safety region for procedures. In our city, there is no study that determines the means of the vertebral foramina diameters, the distance from the midline and its anomalies. It is necessary to rely on CT scans and to make a preoperative plan to avoid complications associated with morphological alterations.

  6. Cross-Disciplinary Analysis of Lymph Node Classification in Lung Cancer on CT Scanning.

    Science.gov (United States)

    El-Sherief, Ahmed H; Lau, Charles T; Obuchowski, Nancy A; Mehta, Atul C; Rice, Thomas W; Blackstone, Eugene H

    2017-04-01

    Accurate and consistent regional lymph node classification is an important element in the staging and multidisciplinary management of lung cancer. Regional lymph node definition sets-lymph node maps-have been created to standardize regional lymph node classification. In 2009, the International Association for the Study of Lung Cancer (IASLC) introduced a lymph node map to supersede all preexisting lymph node maps. Our aim was to study if and how lung cancer specialists apply the IASLC lymph node map when classifying thoracic lymph nodes encountered on CT scans during lung cancer staging. From April 2013 through July 2013, invitations were distributed to all members of the Fleischner Society, Society of Thoracic Radiology, General Thoracic Surgical Club, and the American Association of Bronchology and Interventional Pulmonology to participate in an anonymous online image-based and text-based 20-question survey regarding lymph node classification for lung cancer staging on CT imaging. Three hundred thirty-seven people responded (approximately 25% participation). Respondents consisted of self-reported thoracic radiologists (n = 158), thoracic surgeons (n = 102), and pulmonologists who perform endobronchial ultrasonography (n = 77). Half of the respondents (50%; 95% CI, 44%-55%) reported using the IASLC lymph node map in daily practice, with no significant differences between subspecialties. A disparity was observed between the IASLC definition sets and their interpretation and application on CT scans, in particular for lymph nodes near the thoracic inlet, anterior to the trachea, anterior to the tracheal bifurcation, near the ligamentum arteriosum, between the bronchus intermedius and esophagus, in the internal mammary space, and adjacent to the heart. Use of older lymph node maps and inconsistencies in interpretation and application of definitions in the IASLC lymph node map may potentially lead to misclassification of stage and suboptimal management of lung

  7. Analysis of CT radiation dose based on radiation-dose-structured reports

    International Nuclear Information System (INIS)

    Wang Weipeng; Zhang Yi; Zhang Menglong; Zhang Dapeng; Song Shaojuan

    2014-01-01

    Objective: To analyse the CT radiation dose statistically using the standardized radiation-dose-structured report (RDSR) of digital imaging and communications in medicine (DICOM). Methods: Using the self-designed software, 1230 RDSR files about CT examination were obtained searching on the picture archiving and communication system (PACS). The patient dose database was established by combination of the extracted relevant information with the scanned sites. The patients were divided into adult group (over 10 years) and child groups (0-1 year, 1-5 years, 5-10 years) according to the age. The average volume CT dose index (CTDI vol ) and dose length product (DLP) of all scans were recorded respectively, and then the effective dose (E) was estimated. The DLP value at 75% quantile was calculated and compared with the diagnostic reference level (DRL). Results: In adult group, CTDI vol and DLP values were moderately and positively correlated (r = 0.41), the highest E was observed in upper abdominal enhanced scan, and the DLP value at 75% quantile was 60% higher than DRL. In child group, their CTDI vol in group of 5-10 years was greater than that in groups of 0-1 and 1-5 years (t = 2.42, 2.04, P < 0.05); the DLP value was slightly and positively correlated with the age (r = 0.16), while E was moderately and negatively correlated with the age (r = -0.48). Conclusions: It is a simple and efficient method to use RDSR to obtain the radiation doses of patients. With the popularization of the new equipment and the application of regionalized medical platform, RDSR would become the main tool for the dosimetric level surveying and individual dose recording. (authors)

  8. Tumour heterogeneity in non-small cell lung carcinoma assessed by CT texture analysis: a potential marker of survival

    International Nuclear Information System (INIS)

    Ganeshan, Balaji; Miles, Ken; Panayiotou, Elleny; Burnand, Kate; Dizdarevic, Sabina

    2012-01-01

    To establish the potential for tumour heterogeneity in non-small cell lung cancer (NSCLC) as assessed by CT texture analysis (CTTA) to provide an independent marker of survival for patients with NSCLC. Tumour heterogeneity was assessed by CTTA of unenhanced images of primary pulmonary lesions from 54 patients undergoing 18 F-fluorodeoxyglucose (FDG) PET-CT for staging of NSCLC. CTTA comprised image filtration to extract fine, medium and coarse features with quantification of the distribution of pixel values (uniformity) within the filtered images. Receiver operating characteristics identified thresholds for PET and CTTA parameters that were related to patient survival using Kaplan-Meier analysis. The median (range) survival was 29.5 (1-38) months. 24, 10, 14 and 6 patients had tumour stages I, II, III and IV respectively. PET stage and tumour heterogeneity assessed by CTTA were significant independent predictors of survival (PET stage: Odds ratio 3.85, 95% confidence limits 0.9-8.09, P = 0.002; CTTA: Odds ratio 56.4, 95% confidence limits 4.79-666, p = 0.001). SUV was not a significantly associated with survival. Assessment of tumour heterogeneity by CTTA of non-contrast enhanced images has the potential for to provide a novel, independent predictor of survival for patients with NSCLC. (orig.)

  9. WE-G-207-05: Relationship Between CT Image Quality, Segmentation Performance, and Quantitative Image Feature Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J; Nishikawa, R [University of Pittsburgh, Pittsburgh, PA (United States); Reiser, I [The University of Chicago, Chicago, IL (United States); Boone, J [UC Davis Medical Center, Sacramento, CA (United States)

    2015-06-15

    Purpose: Segmentation quality can affect quantitative image feature analysis. The objective of this study is to examine the relationship between computed tomography (CT) image quality, segmentation performance, and quantitative image feature analysis. Methods: A total of 90 pathology proven breast lesions in 87 dedicated breast CT images were considered. An iterative image reconstruction (IIR) algorithm was used to obtain CT images with different quality. With different combinations of 4 variables in the algorithm, this study obtained a total of 28 different qualities of CT images. Two imaging tasks/objectives were considered: 1) segmentation and 2) classification of the lesion as benign or malignant. Twenty-three image features were extracted after segmentation using a semi-automated algorithm and 5 of them were selected via a feature selection technique. Logistic regression was trained and tested using leave-one-out-cross-validation and its area under the ROC curve (AUC) was recorded. The standard deviation of a homogeneous portion and the gradient of a parenchymal portion of an example breast were used as an estimate of image noise and sharpness. The DICE coefficient was computed using a radiologist’s drawing on the lesion. Mean DICE and AUC were used as performance metrics for each of the 28 reconstructions. The relationship between segmentation and classification performance under different reconstructions were compared. Distributions (median, 95% confidence interval) of DICE and AUC for each reconstruction were also compared. Results: Moderate correlation (Pearson’s rho = 0.43, p-value = 0.02) between DICE and AUC values was found. However, the variation between DICE and AUC values for each reconstruction increased as the image sharpness increased. There was a combination of IIR parameters that resulted in the best segmentation with the worst classification performance. Conclusion: There are certain images that yield better segmentation or classification

  10. Accuracy and reliability of different cone beam computed tomography (CBCT) devices for structural analysis of alveolar bone in comparison with multislice CT and micro-CT.

    Science.gov (United States)

    Van Dessel, Jeroen; Nicolielo, Laura Ferreira Pinheiro; Huang, Yan; Coudyzer, Walter; Salmon, Benjamin; Lambrichts, Ivo; Jacobs, Reinhilde

    The aim of this study was to assess whether cone beam computed tomography (CBCT) may be used for clinically reliable alveolar bone quality assessment in comparison to its clinical alternatives, multislice computed tomography and the gold standard (micro-CT). Six dentate mandibular bone samples were scanned with seven CBCT devices (ProMax 3D Max, NewTom GiANO, Cranex 3D, 3D Accuitomo 170, Carestream 9300, Scanora 3D, I-CAT Next generation), one micro-CT scanner (SkyScan 1174) and one MSCT machine (Somatom Definition Flash) using two protocols (standard and high-resolution). MSCT and CBCT images were automatically spatially aligned on the micro-CT scan of the corresponding sample. A volume of interest was manually delineated on the micro-CT image and overlaid on the other scanning devices. Alveolar bone structures were automatically extracted using the adaptive thresholding algorithm. Based on the resulting binary images, an automatic 3D morphometric quantification was performed in a CT-Analyser (Bruker, Kontich, Belgium). The reliability and measurement errors were calculated for each modality compared to the gold standard micro-CT. Both MSCT and CBCT were associated with a clinically and statistically (P max, bone surface density -0.47 mm-1 min to 0.16 mm-1 max and trabecular thickness 0.15 mm min to 0.31 mm max) were significantly (P max and fractal dimension 0.08 min to 0.17 max) in all scanners compared to micro-CT. However, the structural pattern of the alveolar bone remained similar compared to that of the micro-CT for the ProMax 3D Max, NewTom GiANO, Cranex 3D, 3D Accuitomo 170 and Carestream 9300. On the other hand, the Scanora 3D, i-CAT Next Generation, standard and high-resolution MSCT displayed an overrated bone quantity and aberrant structural pattern compared to other scanning devices. The calculation of morphometric indices had an overall high reliability (intraclass correlation coefficient [ICC] 0.62 min to 0.99 max), except

  11. Analysis of CT and PET/SPECT images for dosimetry calculation

    International Nuclear Information System (INIS)

    Massicano, Felipe; Massicano, Adriana V.F.; Silva, Natanael Gomes da; Cintra, Felipe Belonsi; Yoriyaz, Helio; Carvalho, Rodrigo Mueller de

    2009-01-01

    Computer images are routinely used in diagnostic centers and hospitals. In particular in the field of Nuclear Medicine they help in the diagnosis and planning therapy against cancer. In the case of the planning therapy the quantifying the distribution of dose in patients is very important, because it provides an estimate of the dose in the tumor and healthy tissues, allowing a greater understanding on the response and toxicity caused by this dose. The aim of this study is to analyze both kinds of images: CT and PET/SPECT and their potential utilization for dosimetry calculation. PET or SPECT images were analyzed using a Gamma Camera, brand Medis, model Nuclide-TH/22 through image acquisition of scanned phantoms containing a known activity inside their volume so that a relationship between the number of counts for each voxel in the image and the real activity will be constructed. The heterogeneous organism patient's is specified from the computed tomography (CT) through number of Hounsfield. However, there is not a simple correlation to convert Hounsfield numbers into material tissues, therefore, in this work we developed a software in Java to convert Hounsfield numbers in mass density. Moreover, the software provides a map of tissues and a text file containing the elemental weights to be used by the Monte Carlo transport code MCNP5 to perform dose calculations. (author)

  12. Comparative analysis of carbohydrate active enzymes in Clostridium termitidis CT1112 reveals complex carbohydrate degradation ability.

    Directory of Open Access Journals (Sweden)

    Riffat I Munir

    Full Text Available Clostridium termitidis strain CT1112 is an anaerobic, gram positive, mesophilic, cellulolytic bacillus isolated from the gut of the wood-feeding termite, Nasutitermes lujae. It produces biofuels such as hydrogen and ethanol from cellulose, cellobiose, xylan, xylose, glucose, and other sugars, and therefore could be used for biofuel production from biomass through consolidated bioprocessing. The first step in the production of biofuel from biomass by microorganisms is the hydrolysis of complex carbohydrates present in biomass. This is achieved through the presence of a repertoire of secreted or complexed carbohydrate active enzymes (CAZymes, sometimes organized in an extracellular organelle called cellulosome. To assess the ability and understand the mechanism of polysaccharide hydrolysis in C. termitidis, the recently sequenced strain CT1112 of C. termitidis was analyzed for both CAZymes and cellulosomal components, and compared to other cellulolytic bacteria. A total of 355 CAZyme sequences were identified in C. termitidis, significantly higher than other Clostridial species. Of these, high numbers of glycoside hydrolases (199 and carbohydrate binding modules (95 were identified. The presence of a variety of CAZymes involved with polysaccharide utilization/degradation ability suggests hydrolysis potential for a wide range of polysaccharides. In addition, dockerin-bearing enzymes, cohesion domains and a cellulosomal gene cluster were identified, indicating the presence of potential cellulosome assembly.

  13. Percutaneous Vertebroplasty for Compression Fracture: Analysis of Vertebral Body Volume by CT Volumetry

    International Nuclear Information System (INIS)

    Komemushi, A.; Tanigawa, N.; Kariya, S.; Kojima, H.; Shomura, Y.; Sawada, S.

    2005-01-01

    Purpose: To evaluate the relationships between volume of vertebral bodies with compression fracture (measured by CT volumetry) before percutaneous vertebroplasty, the amount of bone cement injected, and the effect of treatment. Material and Methods: We examined 49 consecutive patients, with 104 vertebral body compression fractures, who underwent percutaneous injection of bone cement. Vertebral body volume was measured by CT volumetry. The patient's pain level was assessed using a visual analog scale (VAS) before and after the procedure. Improvement in VAS was defined as the decrease in VAS after the procedure. Relationships between vertebral body volume, the amount of bone cement, and the effect of treatment were evaluated using Pearson's correlation coefficient test. Results: Average vertebral body volume was 26.3 ±8.1 cm 3 ; average amount of bone cement was 3.2 ±1.1 ml; and average improvement in VAS was 4.9 ±2.7. The vertebral body volume was greater if a larger amount of bone cement was injected. There was a significant positive correlation between vertebral body volume and amount of bone cement ( r ∼ 0.44; P <0.0001). However, there was no correlation between vertebral body volume and improvement in VAS, or between amount of bone cement and improvement in VAS. Conclusion: In percutaneous vertebroplasty for vertebral body compression fracture, there is a positive correlation between vertebral body volume and amount of bone cement, but improvement in VAS does not correlate with vertebral body volume or amount of bone cement

  14. Analysis of hepatic vein variations in healthy people with 64-slice spiral CT

    International Nuclear Information System (INIS)

    Zhang Rong; Li Yong; Shen Jun; Zeng Weike; Li Jieting; Huang Suiqiao; Liang Biling; Liu Chao

    2007-01-01

    Objective: To analyze variations of hepatic vein in healthy people with 64-slice spiral CT. Methods: Seventy-five healthy subjects underwent multi-slice spiral computed (MSCT) hepatic venography. The anatomy of the junction of the hepatic veins with the inferior vena cava and the intrahepatic drainage territory of the hepatic veins and tributaries were evaluated. The hepatic veins were classified according to three anatomic classification (Nakamura's, Marcos's and Kawasaki's classification) methods respectively. Results: There was a common trunk of the middle and left hepatic veins before joining the IVC in 86.7% (65/75)of the cases. In 13.3% (10/75)of the cases, the three main hepatic veins joined the IVC separately. The ratios of Nakamma's classification type A, B, C of hepatic veins were 49.4% (37/75), 37.3% (28/75), and 13.3% (10/75) respectively. The ratios of Marcos's classification type A, B, C of hepatic veins were 56.0% (42/75), 24.0% (18/75), and 20.0% (15/75) respectively. The ratios of Kawasaki's classification type I, II of hepatic vein were 40.0% (30/75) and 60.0% (45/75). Conclusion: Multi-slice spiral CT hepatic venography can provide visualization of peripheral hepatic venous branches in details. (authors)

  15. Measurement and analysis of cardiopulmonary vascular in Lanzhou healthy adults with multislice spiral CT

    International Nuclear Information System (INIS)

    Shi Xiaonan; Guo Shunlin

    2013-01-01

    Objective: To constitute a normal standard of cardiopulmonary vascular diameter and size of normal adult in Lanzhou, and to compared with the other's data reported in the previous bibliography by measuring diameter and area of cardiopulmonary artery lumen of the healthy adults in Lanzhou with multislice spiral CT (MSCT). Methods: Three hundred Lanzhou adults with no cardiopulmonary disease were equally assigned to 3 groups according to their age (A group: 18-39 years, B group: 40-60 years, C group: 61-80 years; 50 females and 50 males in each group). CT data were acquired at the end of deep inspiration phase and measurements were done on 3D reconstruction image with precise landmarks. All the results were statistically analyzed. Results: The diameters and areas of the main pulmonary artery left pulmonary artery right pulmonary artery ascending aorta and descending aorta differed significantly among the 3 groups (P<0.05). In groups B and C, there were significant differences in diameters and areas of pulmonary artery left pulmonary artery and right pulmonary between different genders (P<0.05). Conclusion: Imaging standard is provided for Lanzhou adult in early diagnosis of cardiopulmonary disease. The diameters and areas of main pulmonary artery left pulmonary artery and right pulmonary artery of Lanzhou healthy adults are different from that of other regions. It may be related to the geographical environment and the state of air pollution in Lanzhou. (authors)

  16. Parietal pleural invasion/adhesion of subpleural lung cancer: Quantitative 4-dimensional CT analysis using dynamic-ventilatory scanning

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, Kotaro, E-mail: ksakuma@ohara-hp.or.jp [Department of Radiology, Ohara General Hospital, 6-11 Omachi, Fukushima City, Fukushima 960-8611 (Japan); Department of Radiology and Nuclear Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima City, Fukushima 960-1295 (Japan); Yamashiro, Tsuneo, E-mail: clatsune@yahoo.co.jp [Department of Radiology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 (Japan); Moriya, Hiroshi, E-mail: hrshmoriya@gmail.com [Department of Radiology, Ohara General Hospital, 6-11 Omachi, Fukushima City, Fukushima 960-8611 (Japan); Murayama, Sadayuki, E-mail: sadayuki@med.u-ryukyu.ac.jp [Department of Radiology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 (Japan); Ito, Hiroshi, E-mail: h-ito@fmu.ac.jp [Department of Radiology and Nuclear Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima City, Fukushima 960-1295 (Japan)

    2017-02-15

    Highlights: • 4DCT can be used for assessment of pleural invasion/adhesion by lung cancer. • Quantitative 4DCT indices of lung cancer and adjacent structures are described. • An automatic analysis of pleural invasion/adhesion would be developed in the future. - Abstract: Purpose: Using 4-dimensional dynamic-ventilatory scanning by a 320-row computed tomography (CT) scanner, we performed a quantitative assessment of parietal pleural invasion and adhesion by peripheral (subpleural) lung cancers. Methods: Sixteen patients with subpleural lung cancer underwent dynamic-ventilation CT during free breathing. Neither parietal pleural invasion nor adhesion was subsequently confirmed by surgery in 10 patients, whereas the other 6 patients were judged to have parietal pleural invasion or adhesion. Using research software, we tracked the movements of the cancer and of an adjacent structure such as the rib or aorta, and converted the data to 3-dimensional loci. The following quantitative indices were compared by the Mann-Whitney test: cross-correlation coefficient between time curves for the distances moved from the inspiratory frame by the cancer and the adjacent structure, the ratio of the total movement distances (cancer/adjacent structure), and the cosine similarities between the inspiratory and expiratory vectors (from the cancer to the adjacent structure) and between vectors of the cancer and of the adjacent structure (from inspiratory to expiratory frames). Results: Generally, the movements of the loci of the lung cancer and the adjacent structure were similar in patients with parietal pleural invasion/adhesion, while they were independent in patients without. There were significant differences in all the parameters between the two patient groups (cross-correlation coefficient and the movement distance ratio, P < 0.01; cosine similarities, P < 0.05). Conclusion: These observations suggest that quantitative indices by dynamic-ventilation CT can be utilized as a

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

    International Nuclear Information System (INIS)

    Silva, Alessandro Marcio Hakme da; Silva, Orivaldo Lopes da; Silva Junior, Nelson Ferreira da; Alves, Jose Marcos

    2014-01-01

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

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

    International Nuclear Information System (INIS)

    Shinagawa, Toshio; Hiraiwa, Yoshio; Mizuno, Seio; Kusunoki, Norio; Nitta, Yu; Matsubara, Takao; Iwainaka, Yoichi; Konishi, Hideo

    1992-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  20. Postoperative CT in pancreas transplantation

    International Nuclear Information System (INIS)

    Powell, F.E.; Harper, S.J.F.; Callaghan, C.J.; Shaw, A.; Godfrey, E.M.; Bradley, J.A.; Watson, C.J.E.; Pettigrew, G.J.

    2015-01-01

    Aim: To examine the usage and value of computed tomography (CT) following simultaneous pancreas and kidney (SPK) transplantation. Materials and methods: Indications for postoperative CT, key findings, and their influence on management were determined by retrospective analysis. Results: Ninety-eight patients underwent 313 CT examinations. Common indications for the examinations included suspected intra-abdominal collection (31.1%) and elevated serum amylase/lipase (24.1%). CT findings most frequently showed non-specific mild inflammation (27.6%), a normal scan (17.1%) and fluid collections (16.3%). High capillary blood glucose (CBG) was associated with resultant CT demonstration of graft vascular abnormalities, but otherwise, particular clinical indications were not associated with specific CT findings. Conclusion: Clinical findings in patients with SPK transplants are non-specific. The pattern of abnormalities encountered is significantly different to those seen in native pancreatic disease and demands a tailored protocol. CT enables accurate depiction of vascular abnormalities and fluid collections, thus reducing the number of surgical interventions that might otherwise be required. Elevated CBG should prompt urgent CT to exclude potentially reversible vascular complications. - Highlights: • The value of CT following simultaneous pancreas and kidney transplantation was assessed. • 313 CT scans were performed on 98 patients between January 2005 and August 2010. • Elevated blood glucose was associated with CT findings of graft vascular anomalities. • CT was particularly useful in directing operative versus non-operative intervention.

  1. Machine learning-based quantitative texture analysis of CT images of small renal masses: Differentiation of angiomyolipoma without visible fat from renal cell carcinoma.

    Science.gov (United States)

    Feng, Zhichao; Rong, Pengfei; Cao, Peng; Zhou, Qingyu; Zhu, Wenwei; Yan, Zhimin; Liu, Qianyun; Wang, Wei

    2018-04-01

    To evaluate the diagnostic performance of machine-learning based quantitative texture analysis of CT images to differentiate small (≤ 4 cm) angiomyolipoma without visible fat (AMLwvf) from renal cell carcinoma (RCC). This single-institutional retrospective study included 58 patients with pathologically proven small renal mass (17 in AMLwvf and 41 in RCC groups). Texture features were extracted from the largest possible tumorous regions of interest (ROIs) by manual segmentation in preoperative three-phase CT images. Interobserver reliability and the Mann-Whitney U test were applied to select features preliminarily. Then support vector machine with recursive feature elimination (SVM-RFE) and synthetic minority oversampling technique (SMOTE) were adopted to establish discriminative classifiers, and the performance of classifiers was assessed. Of the 42 extracted features, 16 candidate features showed significant intergroup differences (P Machine learning analysis of CT texture features can facilitate the accurate differentiation of small AMLwvf from RCC. • Although conventional CT is useful for diagnosis of SRMs, it has limitations. • Machine-learning based CT texture analysis facilitate differentiation of small AMLwvf from RCC. • The highest accuracy of SVM-RFE+SMOTE classifier reached 93.9 %. • Texture analysis combined with machine-learning methods might spare unnecessary surgery for AMLwvf.

  2. Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT.

    Science.gov (United States)

    Cho, S H; Sung, Y M; Kim, M S

    2012-10-01

    The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images.

  3. Quantitative analysis of the patellofemoral motion pattern using semi-automatic processing of 4D CT data.

    Science.gov (United States)

    Forsberg, Daniel; Lindblom, Maria; Quick, Petter; Gauffin, Håkan

    2016-09-01

    To present a semi-automatic method with minimal user interaction for quantitative analysis of the patellofemoral motion pattern. 4D CT data capturing the patellofemoral motion pattern of a continuous flexion and extension were collected for five patients prone to patellar luxation both pre- and post-surgically. For the proposed method, an observer would place landmarks in a single 3D volume, which then are automatically propagated to the other volumes in a time sequence. From the landmarks in each volume, the measures patellar displacement, patellar tilt and angle between femur and tibia were computed. Evaluation of the observer variability showed the proposed semi-automatic method to be favorable over a fully manual counterpart, with an observer variability of approximately 1.5[Formula: see text] for the angle between femur and tibia, 1.5 mm for the patellar displacement, and 4.0[Formula: see text]-5.0[Formula: see text] for the patellar tilt. The proposed method showed that surgery reduced the patellar displacement and tilt at maximum extension with approximately 10-15 mm and 15[Formula: see text]-20[Formula: see text] for three patients but with less evident differences for two of the patients. A semi-automatic method suitable for quantification of the patellofemoral motion pattern as captured by 4D CT data has been presented. Its observer variability is on par with that of other methods but with the distinct advantage to support continuous motions during the image acquisition.

  4. Quantitative analysis of dynamic airway changes after methacholine and salbutamol inhalation on xenon-enhanced chest CT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Joon; Goo, Jin Mo; Kim, Jong Hyo; Park, Eun-Ah [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Radiation Medicine, Medical Research Center, Seoul (Korea, Republic of); Lee, Chang Hyun [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Radiation Medicine, Medical Research Center, Seoul (Korea, Republic of); Seoul National University Hospital, Healthcare Gangnam Center, Seoul (Korea, Republic of); Jung, Jae-Woo; Park, Heung-Woo [Seoul National University College of Medicine, Department of Internal Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Allergy and Clinical Immunology, Seoul (Korea, Republic of); Cho, Sang-Heon [Seoul National University Hospital, Healthcare Gangnam Center, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Internal Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Allergy and Clinical Immunology, Seoul (Korea, Republic of)

    2012-11-15

    To investigate the dynamic changes in airways in response to methacholine and salbutamol inhalation and to correlate the xenon ventilation index on xenon-enhanced chest CTs in asthmatics. Thirty-one non-smokers (6 normal, 25 asthmatics) underwent xenon-enhanced chest CT and pulmonary function tests. Images were obtained at three stages (basal state, after methacholine inhalation and after salbutamol inhalation), and the total xenon ventilation index (TXVI) as well as airway values were measured and calculated. The repeated measures ANOVA and Spearman's correlation coefficient were used for statistical analysis. TXVI in the normal group did not significantly change (P > 0.05) with methacholine and salbutamol. For asthmatics, however, the TXVI significantly decreased after methacholine inhalation and increased after salbutamol inhalation (P < 0.05). Of the airway parameters, the airway inner area (IA) significantly increased after salbutamol inhalation in all airways (P < 0.01) in asthmatics. Airway IA, wall thickness and wall area percentage did not significantly decrease after methacholine inhalation (P > 0.05). IA of the large airways was well correlated with basal TXVI, FEV{sub 1} and FVC (P < 0.05). Airway IA is the most reliable parameter for reflecting the dynamic changes after methacholine and salbutamol inhalation, and correlates well with TXVI in asthmatics on xenon-enhanced CT. (orig.)

  5. Accuracy of whole-body FDG-PET and FDG-PET/CT in M staging of nasopharyngeal carcinoma: A systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Chang, Ming-Che; Chen, Jin-Hua; Liang, Ji-An; Yang, Kuang-Tao; Cheng, Kai-Yuan; Kao, Chia-Hung

    2013-01-01

    Background: A meta-analysis was conducted to evaluate the accuracy of whole-body positron emission tomography (PET) or PET/CT in M staging of nasopharyngeal carcinoma (NPC). Methods: Through a search of relevant English language studies from October 1996 to September 2011, pooled estimated sensitivity, specificity, positive likelihood ratios, negative likelihood ratios, and summary receiver operating characteristic (SROC) curves of whole-body PET or PET/CT in M staging of NPC were calculated. Results: Three PET and 5 PET/CT studies were identified. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of FDG-PET or PET/CT were 0.83 (95% confidence interval [CI], 0.77–0.88), 0.97 (95% CI, 0.95–0.98), 23.38 (95% CI, 16.22–33.69), and 0.19 (95% CI, 0.13–0.25), respectively. The area under curve was 0.9764 and Q* index estimate was 0.9307 for FDG-PET or PET/CT. Conclusion: Current evidence confirms the good diagnostic performance of the whole-body FDG-PET or PET/CT in M staging of NPC

  6. Establishment study of the in vivo imaging analysis with small animal imaging modalities (micro-PET and micro-SPECT/CT) for bio-drug development

    International Nuclear Information System (INIS)

    Jang, Beomsu; Park, Sanghyeon; Park, Jeonghoon; Jo, Sungkee; Jung, Uhee; Kim, Seolwha; Lee, Yunjong; Choi, Daeseong

    2011-01-01

    In this study, we established the image acquisition and analysis procedures of micro-PET, SPECT/CT using the experimental animal (mouse) for the development of imaging assessment method for the bio-drug. We examined the micro-SPECT/CT, PET imaging study using the Siemens Inveon micro-multimodality system (SPECT/CT) and micro-PET with 99m Tc-MDP, DMSA, and 18 F-FDG. SPECT imaging studies using 3 types of pinhole collimators. 5-MWB collimator was used for SPECT image study. To study whole-body distribution, 99m Tc-MDP SPECT image study was performed. We obtained the fine distribution image. And the CT images was obtained to provide the anatomical information. And then these two types images are fused. To study specific organ uptake, we examined 99 mTc-DMSA SPECT/CT imaging study. We also performed the PET image study using U87MG tumor bearing mice and 18 F-FDG. The overnight fasting, warming and anesthesia with 2% isoflurane pretreatment enhance the tumor image through reducing the background uptake including brown fat, harderian gland and skeletal muscles. Also we got the governmental approval for use of x-ray generator for CT and radioisotopes as sealed and open source. We prepared the draft of process procedure for the experimental animal imaging facility. These research results can be utilized as a basic image study protocols and data for the image assessment of drugs including biological drug

  7. SU-E-I-62: Assessing Radiation Dose Reduction and CT Image Optimization Through the Measurement and Analysis of the Detector Quantum Efficiency (DQE) of CT Images Using Different Beam Hardening Filters

    International Nuclear Information System (INIS)

    Collier, J; Aldoohan, S; Gill, K

    2014-01-01

    Purpose: Reducing patient dose while maintaining (or even improving) image quality is one of the foremost goals in CT imaging. To this end, we consider the feasibility of optimizing CT scan protocols in conjunction with the application of different beam-hardening filtrations and assess this augmentation through noise-power spectrum (NPS) and detector quantum efficiency (DQE) analysis. Methods: American College of Radiology (ACR) and Catphan phantoms (The Phantom Laboratory) were scanned with a 64 slice CT scanner when additional filtration of thickness and composition (e.g., copper, nickel, tantalum, titanium, and tungsten) had been applied. A MATLAB-based code was employed to calculate the image of noise NPS. The Catphan Image Owl software suite was then used to compute the modulated transfer function (MTF) responses of the scanner. The DQE for each additional filter, including the inherent filtration, was then computed from these values. Finally, CT dose index (CTDIvol) values were obtained for each applied filtration through the use of a 100 mm pencil ionization chamber and CT dose phantom. Results: NPS, MTF, and DQE values were computed for each applied filtration and compared to the reference case of inherent beam-hardening filtration only. Results showed that the NPS values were reduced between 5 and 12% compared to inherent filtration case. Additionally, CTDIvol values were reduced between 15 and 27% depending on the composition of filtration applied. However, no noticeable changes in image contrast-to-noise ratios were noted. Conclusion: The reduction in the quanta noise section of the NPS profile found in this phantom-based study is encouraging. The reduction in both noise and dose through the application of beam-hardening filters is reflected in our phantom image quality. However, further investigation is needed to ascertain the applicability of this approach to reducing patient dose while maintaining diagnostically acceptable image qualities in a

  8. Computer-aided analysis of CT images for the differentiation of cerebral tumors

    International Nuclear Information System (INIS)

    Michalik, M.; Michalik, S.; Bornholdt, F.

    1988-01-01

    For the integration of CT imaging into the differential diagnostics of intracranial space occupations, the selection and description of characteristics facilitating a good discrimination of serveral classes of tumors becomes a very important task. From images of 93 patients with the most frequent brain tumors the optimal set of characteristics was determined. The four most significant characteristics for the differentiation of brain tumors are 'uptake of contrast medium by the tumor', 'deliniation of the tumor contours', 'progression of the tumor' and the 'average tumor density after administration of contrast media'. Very good results were obtained for the differentiation of menigneomas with and without anaplasia and for the differentiation of meningeomas from all other tumors examined. The differentiation of the degree of malignancy for various gliomatous tumors was difficult. An accurate reclassification with the computer program was obtained for 83.4% of all tumors. (author)

  9. Evaluation of CT in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, Norio; Miura, Yukio; Ohnishi, Mitsunori; Kamikon-ya, Norihiko; Sakamoto, Yoshisato; Miura, Takashi; Sakamoto, Kiyoshi; Takayasu, Yoshio

    1985-06-01

    In order to evaluate the diagnostic ability of CT in hepatocellular carcinoma, four kinds of CT images were comparatively studied by the accuracy and ROC (receiver operating characteristic) curve analysis. As a result, it was clarified that CT images were evaluated more objectively by ROC curve analysis than by accuracy. The diagnostic ability of existence and differentiation of tumor in the liver were higher in order of plain CT, contrast enhanced CT (CECT), bolus CT and CT arteriography (CTA). Therefore, in an usual CT examination intended to make differential diagnosis in space occupying liver disease, bolus CT seems to be indispensable, and also CTA is essential where diagnosis is difficult even by bolus CT.

  10. Sentinel lymph node mapping using SPECT/CT and gamma probe in endometrial cancer: an analysis of parameters affecting detection rate

    Energy Technology Data Exchange (ETDEWEB)

    Sahbai, Samine; La Fougere, Christian; Dittmann, Helmut [University Hospital Tuebingen, Nuclear Medicine and Clinical Molecular Imaging, Tuebingen (Germany); Taran, Florin-Andrei; Wallwiener, Diethelm; Brucker, Sara [University Hospital Tuebingen, Gynecology and Obstetrics, Tuebingen (Germany); Staebler, Annette [University Hospital Tuebingen, Pathology, Tuebingen (Germany)

    2017-08-15

    SPECT/CT after pericervical injection of technetium-99 m-nanocolloid was shown to be suitable for sentinel lymph node (SLN) mapping in endometrial cancer (EC). The aim of this study was to analyze factors affecting successful SLN detection by means of SPECT/CT such as imaging findings, patient characteristics and tumor biology in a large cohort of patients. One hundred and forty-five consecutive patients suffering from EC who received pre-surgical SLN mapping at our institution between 2011 and 2016 were included in this analysis. SPECT/CT data of abdomen and pelvis (mean 4:20 ± 1:20 h p.i.) were acquired after pericervical injection of technetium-99 m-nanocolloid (mean 230 ± 45 MBq) in all patients. Surgical staging was performed on the day after. Acquisition parameters, patient characteristics, SPECT/CT findings as well as histopathological results were collected. A total of 282 SLNs were identified by means of SPECT/CT. Overall, preoperative and intraoperative SLN detection rates were 86%, 76% and 74% respectively. The most important factor associated with failure to detect SLNs was the presence of high bone marrow on SPECT/CT (p = 0.005). Peritoneal/abdominal radioactivity was also associated with missed SLN detection in SPECT/CT (p = 0.02). However, the presence of liver/spleen uptake on its own was not predictive for detection failure. Low numbers of detected SLNs in SPECT/CT were slightly related with older age and lower injected activity. No significant influence was found for the parameters of tumor histology and stage, lymph node involvement and the time gap between injection and imaging. Venous drainage as indicated by bone marrow uptake is the most important factor associated with scintigraphic SLN detection failure. Moreover, high peritoneal and abdominal activity was also associated with detection failure. Thus, meticulous application of the radiotracer is crucial in EC. (orig.)

  11. Sigmoid sinus diverticulum and pulsatile tinnitus - Analysis of CT scans from 15 cases

    International Nuclear Information System (INIS)

    Liu, Zhaohui; Wang, Zhenchang; Xian, Junfang; Wang, Yongzhe; Liang, Xihong; Chen, Chengfang; Gong, Shusheng; Ma, Xiaobo; Li, Yi

    2013-01-01

    Background: Although the imaging features of sigmoid sinus diverticulum induced pulsatile tinnitus (PT) have been presented in some extent, detailed imaging findings still have not been systematically evaluated and precise diagnostic radiographic criteria has not been established. Purpose: To examine the computed tomography (CT) characteristics of sigmoid sinus diverticulum accompanied with PT. Material and Methods: Fifteen PT patients with sigmoid sinus diverticula proven by surgery were recruited after consenting. CT images of 15 patients were obtained and analyzed, including features of diverticula, brain venous systems, integrity of the sigmoid plate, and the degree of temporal bone pneumatization. Results: Sigmoid sinus diverticulum was located on the same side of PT in 15 patients. Diverticula originated at the superior curve of the sigmoid sinus in 11 patients and the descending segment of the sigmoid sinus in four patients. Sigmoid sinus diverticula focally eroded into the adjacent mastoid air cells in 12 patients and mastoid cortex in three patients. Among eight patients with unilateral dominant brain venous systems, the diverticula were seen on the dominant side in seven patients and non-dominant side in one patient. In contrast, the other seven patients showed co-dominant brain venous systems, with three presenting diverticula on the right side and four on the left. More notably, dehiscent sigmoid plate on the PT side was demonstrated in all patients. In addition, temporal bone hyper-pneumatization was found in nine patients, good and moderate pneumatization in three patients, respectively. Conclusion: Dehiscent sigmoid plate and extensive temporal bone pneumatization are two important imaging characteristics of the PT induced by sigmoid sinus diverticulum

  12. Comparative analysis of the radiation shield effect in an abdominal CT scan

    International Nuclear Information System (INIS)

    Kim, Seon-Chil; Kim, Young-Jae; Lee, Joon-Seok; Dong, Kyung-Rae; Chung, Woon-Kwan; Lim, Chang-Seon

    2014-01-01

    This study measured and compared the dose on the eyeballs and the thyroid with and without the use of a shield by applying the abdominal examination protocol used in an actual examination to a 64-channel computed tomography (CT) scan. A dummy phantom manufactured from acryl was used to measure the dose to the eyeballs and the thyroid of a patient during a thoraco-abdominal CT scan. The dose was measured using three dosimeters (optically-stimulated luminescence dosimeter (OSLD), thermoluminescence dosimeter (TLD) and photoluminescence dosimeter (PLD)) attached to the surfaces of three parts (left and right eyeballs and thyroid) in a phantom with and without the use of a shield for the eyeballs and the thyroid. Two types of shields (1-mm barium shielding sheet and 1-mm tungsten shielding sheet) were used for the measurements. The goggles and the lead shield, which are normally used in clinical practice, were used to compare the shield ratios of the shields. According to the results of the measurements made by using the OSLD, the shield ratios of the barium and the tungsten sheets were in the range of 34 - 36%. The measurements made by using the TLD showed that the shield ratio of the barium sheet was 6.25% higher than that of the tungsten sheet. When the PLD was used for the measurement, the shield ratio of the barium sheet was 33.34%, which was equivalent to that of the tungsten sheet. These results confirmed that the cheap barium sheet had a better shielding effect than the expensive tungsten sheet.

  13. Cost analysis of colorectal cancer screening with CT colonography in Italy.

    Science.gov (United States)

    Mantellini, Paola; Lippi, Giuseppe; Sali, Lapo; Grazzini, Grazia; Delsanto, Silvia; Mallardi, Beatrice; Falchini, Massimo; Castiglione, Guido; Carozzi, Francesca Maria; Mascalchi, Mario; Milani, Stefano; Ventura, Leonardo; Zappa, Marco

    2018-06-01

    Unit costs of screening CT colonography (CTC) can be useful for cost-effectiveness analyses and for health care decision-making. We evaluated the unit costs of CTC as a primary screening test for colorectal cancer in the setting of a randomized trial in Italy. Data were collected within the randomized SAVE trial. Subjects were invited to screening CTC by mail and requested to have a pre-examination consultation. CTCs were performed with 64- and 128-slice CT scanners after reduced or full bowel preparation. Activity-based costing was used to determine unit costs per-process, per-participant to screening CTC, and per-subject with advanced neoplasia. Among 5242 subjects invited to undergo screening CTC, 1312 had pre-examination consultation and 1286 ultimately underwent CTC. Among 129 subjects with a positive CTC, 126 underwent assessment colonoscopy and 67 were ultimately diagnosed with advanced neoplasia (i.e., cancer or advanced adenoma). Cost per-participant of the entire screening CTC pathway was €196.80. Average cost per-participant for the screening invitation process was €17.04 and €9.45 for the pre-examination consultation process. Average cost per-participant of the CTC execution and reading process was €146.08 and of the diagnostic assessment colonoscopy process was €24.23. Average cost per-subject with advanced neoplasia was €3777.30. Cost of screening CTC was €196.80 per-participant. Our data suggest that the more relevant cost of screening CTC, amenable of intervention, is related to CTC execution and reading process.

  14. Sigmoid sinus diverticulum and pulsatile tinnitus - Analysis of CT scans from 15 cases

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhaohui; Wang, Zhenchang; Xian, Junfang; Wang, Yongzhe; Liang, Xihong [Dept. of Radiology, Capital Medical Univ., Beijing Tongren Hospital, Beijing (China); Chen, Chengfang; Gong, Shusheng; Ma, Xiaobo; Li, Yi [Dept. of Otolaryngology Head and Neck Surgery, Capital Medical Univ., Beijing Tongren Hospital, Beijing (China)

    2013-09-15

    Background: Although the imaging features of sigmoid sinus diverticulum induced pulsatile tinnitus (PT) have been presented in some extent, detailed imaging findings still have not been systematically evaluated and precise diagnostic radiographic criteria has not been established. Purpose: To examine the computed tomography (CT) characteristics of sigmoid sinus diverticulum accompanied with PT. Material and Methods: Fifteen PT patients with sigmoid sinus diverticula proven by surgery were recruited after consenting. CT images of 15 patients were obtained and analyzed, including features of diverticula, brain venous systems, integrity of the sigmoid plate, and the degree of temporal bone pneumatization. Results: Sigmoid sinus diverticulum was located on the same side of PT in 15 patients. Diverticula originated at the superior curve of the sigmoid sinus in 11 patients and the descending segment of the sigmoid sinus in four patients. Sigmoid sinus diverticula focally eroded into the adjacent mastoid air cells in 12 patients and mastoid cortex in three patients. Among eight patients with unilateral dominant brain venous systems, the diverticula were seen on the dominant side in seven patients and non-dominant side in one patient. In contrast, the other seven patients showed co-dominant brain venous systems, with three presenting diverticula on the right side and four on the left. More notably, dehiscent sigmoid plate on the PT side was demonstrated in all patients. In addition, temporal bone hyper-pneumatization was found in nine patients, good and moderate pneumatization in three patients, respectively. Conclusion: Dehiscent sigmoid plate and extensive temporal bone pneumatization are two important imaging characteristics of the PT induced by sigmoid sinus diverticulum.

  15. CT imaging during microwave ablation: Analysis of spatial and temporal tissue contraction

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dong; Brace, Christopher L., E-mail: clbrace@wisc.edu [Departments of Radiology and Biomedical Engineering, University of Wisconsin, Madison, Wisconsin 53705 (United States)

    2014-11-01

    Purpose: To analyze the spatial distribution and temporal development of liver tissue contraction during high-temperature ablation by using intraprocedural computed tomography (CT) imaging. Methods: A total of 46 aluminum fiducial markers were positioned in a 60 × 45 mm grid, in a single plane, around a microwave ablation antenna in each of six ex vivo bovine liver samples. Ablations were performed for 10 min at 100 W. CT data of the liver sample were acquired every 30 s during ablation. Fiducial motion between acquisitions was tracked in postprocessing and used to calculate measures of tissue contraction and contraction rates. The spatial distribution and temporal evolution of contraction were analyzed. Results: Fiducial displacement indicated that the zone measured postablation was 8.2 ± 1.8 mm (∼20%) smaller in the radial direction and 7.1 ± 1.0 mm (∼10%) shorter in the longitudinal direction than the preablation tissue dimension. Therefore, the total ablation volume was reduced from its preablation value by approximately 45%. Very little longitudinal contraction was noted in the distal portion of the ablation zone. Central tissues contracted more than 60%, which was near an estimated limit of ∼70% based on initial water content. More peripheral tissues contracted only 15% in any direction. Contraction rates peaked during the first 60 s of heating with a roughly exponential decay over time. Conclusions: Ablation zones measured posttreatment are significantly smaller than the pretreatment tissue dimensions. Tissue contraction is spatially dependent, with the greatest effect occurring in the central ablation zone. Contraction rate peaks early and decays over time.

  16. Surface and bulk 3D analysis of natural and processed ruby using electron probe micro analyzer and X-ray micro CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Rakesh K., E-mail: rakesh.materialscience@gmail.com; Singh, Saroj K.; Mishra, B.K.

    2016-08-15

    Highlights: • Firm linking between two advance techniques: Micro-CT and EPMA for mineral analysis. • Attempt to identify and differentiate the treated gem stone from natural counterpart. • 3D structural and surface elemental analysis of the natural gem stone. - Abstract: The change in surface compositional and bulk structural characteristics of the natural ruby stone, before and after heat treatment with lead oxide has been analyzed using two advance characterization techniques like: X-ray micro CT scan (μ-CT) and electron probe micro analyzer (EPMA). The analytical correlation between these two techniques in identification as well as in depth study of the ores and minerals before and after processing has been presented. Also, we describe the aesthetic enhancement of a low quality defective ruby stone by lead oxide filling and the sequential analysis of this ruby stone before and after treatment using these two advanced techniques to identify and to confirm the change in its aesthetic value. The cracks healing and pores filling by the metal oxide on the surface of the ruby have been analyzed using μ-CT and EPMA. Moreover, in this work we describe the advance characterization of the repaired gem stones especially ruby stones. This work will light up the path for in-depth understanding of diffusion mechanism and abstract information of impurity particles inside the minerals. Based on these observations, EPMA and micro CT are shown to be powerful tools for the identification as well as research in gem stones.

  17. A preliminary comprehensive dynamic analysis of the typical FaCT scenarios with JSFR and related fuel cycle facilities

    International Nuclear Information System (INIS)

    Shiotani, Hiroki; Ono, Kiyoshi; Ogawa, Takashi; Koma, Yoshikazu; Kawaguchi, Koichi

    2009-01-01

    A preliminary comprehensive dynamic analysis of the typical Fast Reactor (FR) deployment scenarios with JSFR and related fuel cycle facilities developed in 'FaCT: Fast Reactor Cycle Technology Development Project' was conducted. The scenarios were evaluated from some of the development targets and design goals in the FaCT project. The isotopic compositions of the nuclear fuels and wastes and the quantities of radioactive wastes (HLWs, LLWs) from Japanese nuclear fuel cycle facilities were calculated to grasp the sustainability characteristics. Regarding the long-term economics, the total cash out-flows and the average electricity generation costs to 22nd century were calculated. Cash out-flow peaks and waste generation peaks were found from 2030s to 2050s, 2090s to 2110s, and 2150s to 2170s because of the cost and wastes from decommissioning of the nuclear power plants and reprocessing plants for LWR spent fuel and the construction costs of them. Firstly, the major results of the reference case are explained combined with introduction of the function of the dynamic analysis tool (Supply Chain Management Code). The analysis is related to sustainability and economics in FaCT project development targets since they are important in the sustainability and economics evaluation. Secondly, the comparisons between the reference case and the three other option cases with their own issues of choice are explained. Those options are different breeding ratios, dual-purpose reprocessing plant, and Am-Cm recycling. As the tentative conclusions of the analyses are: the exploration of the optimal breeding ratio between B.R. =1.1 and 1.2 at the start up stage of FR is regarded as reasonable; the cost reduction of the dual purpose reprocessing plant resulted from the facility integration was confirmed though the cost estimation of the facility should be modified, it is a little bit too hasty to decide the manner of MA recycling because many issues to be considered are left at present

  18. WE-FG-202-03: Quantitative CT-Based Analysis to Assess Lung Injury Following Proton Radiotherapy

    International Nuclear Information System (INIS)

    Underwood, T; Grassberger, C; Willers, H; MacDonald, S; Jimenez, R; Paganetti, H

    2016-01-01

    Purpose: Relative to photon alternatives, the increased dose-conformity associated with proton therapy is expected to reduce the extent of radiation-induced lung toxicity. However, analysis of follow-up data is yet to be published in this area. In this study we retrospectively analyzed late-phase HU changes for proton therapy cohorts of chest wall and lung patients. Methods: From our institution’s register of patients treated using double-scattered protons, all chest wall and stereotactic lung cases (treated 2011–2012 and 2008–2014 respectively) were initially considered. Follow-up CT data were accessible for 10 chest wall cases (prescribed 50.4 GyRBE in 28 fractions) and 16 lung cases (prescribed 42–50 GyRBE in 3–4 fractions). CT time-points ranged from 0.5–3.5 years post-treatment. Planning doses were recalculated using TOPAS Monte Carlo simulations and mapped onto the follow-up images using deformable registration. Excluding internal target volumes, changes in HU between each patient’s planning and follow-up CT(s) were evaluated for dose bins of 2–30 GyRBE (2 GyRBE increments). Results: Linear increases in HU per unit dose, with correlations statistically significant at the 1% level (one-sided Spearman’s rank test), were evident for all 10 chest wall cases and 14/16 lung cases. The mean changes in HU/Gy were: 1.76 (SD=0.73) for the chest wall cohort, and 1.40 (SD=0.87) for the lung cohort. The median scan times post treatment were 21 and 12 months respectively. All 26 patients developed solid consolidation (scar-like radiographic opacities) within the exposed lung(s). Conclusion: Analysis of follow-up CTs revealed statistically significant correlations in HU-change/dose for two proton cohorts (lung and chest wall). Quantitatively, the late-phase changes we report broadly match published photon data. Further analysis of such radiographic changes, particularly via matched cohort studies drawing upon consistent imaging protocols, could play an

  19. WE-FG-202-03: Quantitative CT-Based Analysis to Assess Lung Injury Following Proton Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, T [Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); University College London, London (United Kingdom); Grassberger, C; Willers, H; MacDonald, S; Jimenez, R; Paganetti, H [Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: Relative to photon alternatives, the increased dose-conformity associated with proton therapy is expected to reduce the extent of radiation-induced lung toxicity. However, analysis of follow-up data is yet to be published in this area. In this study we retrospectively analyzed late-phase HU changes for proton therapy cohorts of chest wall and lung patients. Methods: From our institution’s register of patients treated using double-scattered protons, all chest wall and stereotactic lung cases (treated 2011–2012 and 2008–2014 respectively) were initially considered. Follow-up CT data were accessible for 10 chest wall cases (prescribed 50.4 GyRBE in 28 fractions) and 16 lung cases (prescribed 42–50 GyRBE in 3–4 fractions). CT time-points ranged from 0.5–3.5 years post-treatment. Planning doses were recalculated using TOPAS Monte Carlo simulations and mapped onto the follow-up images using deformable registration. Excluding internal target volumes, changes in HU between each patient’s planning and follow-up CT(s) were evaluated for dose bins of 2–30 GyRBE (2 GyRBE increments). Results: Linear increases in HU per unit dose, with correlations statistically significant at the 1% level (one-sided Spearman’s rank test), were evident for all 10 chest wall cases and 14/16 lung cases. The mean changes in HU/Gy were: 1.76 (SD=0.73) for the chest wall cohort, and 1.40 (SD=0.87) for the lung cohort. The median scan times post treatment were 21 and 12 months respectively. All 26 patients developed solid consolidation (scar-like radiographic opacities) within the exposed lung(s). Conclusion: Analysis of follow-up CTs revealed statistically significant correlations in HU-change/dose for two proton cohorts (lung and chest wall). Quantitatively, the late-phase changes we report broadly match published photon data. Further analysis of such radiographic changes, particularly via matched cohort studies drawing upon consistent imaging protocols, could play an

  20. A novel framework for the temporal analysis of bone mineral density in metastatic lesions using CT images of the femur

    Science.gov (United States)

    Knoop, Tom H.; Derikx, Loes C.; Verdonschot, Nico; Slump, Cornelis H.

    2015-03-01

    In the progressive stages of cancer, metastatic lesions in often develop in the femur. The accompanying pain and risk of fracture dramatically affect the quality of life of the patient. Radiotherapy is often administered as palliative treatment to relieve pain and restore the bone around the lesion. It is thought to affect the bone mineralization of the treated region, but the quantitative relation between radiation dose and femur remineralization remains unclear. A new framework for the longitudinal analysis of CT-scans of patients receiving radiotherapy is presented to investigate this relationship. The implemented framework is capable of automatic calibration of Hounsfield Units to calcium equivalent values and the estimation of a prediction interval per scan. Other features of the framework are temporal registration of femurs using elastix, transformation of arbitrary Regions Of Interests (ROI), and extraction of metrics for analysis. Build in Matlab, the modular approach aids easy adaptation to the pertinent questions in the explorative phase of the research. For validation purposes, an in-vitro model consisting of a human cadaver femur with a milled hole in the intertrochanteric region was used, representing a femur with a metastatic lesion. The hole was incrementally stacked with plates of PMMA bone cement with variable radiopaqueness. Using a Kolmogorov-Smirnov (KS) test, changes in density distribution due to an increase of the calcium concentration could be discriminated. In a 21 cm3 ROI, changes in 8% of the volume from 888 ± 57mg • ml-1 to 1000 ± 80mg • ml-1 could be statistically proven using the proposed framework. In conclusion, the newly developed framework proved to be a useful and flexible tool for the analysis of longitudinal CT data.

  1. CSF-ctDNA SMSEQ Analysis to Tailor the Treatment of a Patient with Brain Metastases: A Case Report

    Directory of Open Access Journals (Sweden)

    Wen-Tsung  Huang

    2018-02-01

    Full Text Available Brain metastases are the most common neurological complications of adult cancers, accounting for more than half of brain tumors. The incidence of brain metastases may be increasing due to improved detection of small lesions by advanced imaging technologies. Given the fast evolution of targeted and immunotherapy regimens, it is essential to serially assess brain malignancies during the disease course for disease monitoring and tailoring of the therapeutic management. For such serial and repetitive assessment, cerebrospinal fluid (CSF could be the biological fluid of choice to supplement cytology examination for the presence or absence of CNS malignancy, as well as provide extensive information on tumor mutational profile for personalization of treatment. The case described here emphasizes the importance of CSF-ctDNA analysis with the CellMax SMSEQ technology that led to treatment adjustment resulting in clinical remission of the patient.

  2. Differences in CT features of peritoneal carcinomatosis, sarcomatosis, and lymphomatosis: Retrospective analysis of 122 cases at a tertiary cancer institution

    International Nuclear Information System (INIS)

    O'Neill, A.C.; Shinagare, A.B.; Rosenthal, M.H.; Tirumani, S.H.; Jagannathan, J.P.; Ramaiya, N.H.

    2014-01-01

    Aims: To study the differences in the imaging features of spread from the three cancer cell lines, namely epithelial, sarcomatoid, and lymphoid, resulting in peritoneal carcinomatosis, peritoneal sarcomatosis, and peritoneal lymphomatosis, respectively. Materials and methods: In this institutional review board-approved Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study, an electronic radiology database was searched to identify patients with peritoneal tumour spread who underwent CT imaging at Dana-Farber Cancer Institute, a tertiary cancer institution, between January 2011 and December 2012. Out of 1214 patients with possible peritoneal tumour spread on the radiology reports, 122 patients were included with histopathologically confirmed peritoneal disease (50 randomly selected patients with peritoneal carcinomatosis and sarcomatosis each, and all 22 patients with lymphomatosis). Two blinded, fellowship-trained radiologists in consensus reviewed the CT images in random order and recorded the imaging findings of peritoneal tumour spread. The statistical analysis was performed in two steps: the first comparing incidence of various features in each group and the second step was a pairwise analysis between each cohort. Results: Peritoneal carcinomatosis more frequently had ascites, peritoneal thickening, and omental cake (all p ≤ 0.001). Measurable nodules were less common in peritoneal carcinomatosis (p < 0.001), and when present, were ill-defined and had an irregular outline (p ≤ 0.002). Peritoneal sarcomatosis more often had discrete nodules that were well defined and had a smooth outline and less frequently had ascites, peritoneal thickening, omental caking, serosal implants, and lymphadenopathy (all p ≤ 0.005). Peritoneal lymphomatosis frequently involved the omentum and mesentery, and often had associated lymphadenopathy and splenomegaly (all p ≤ 0.002). Conclusion: Peritoneal carcinomatosis, sarcomatosis

  3. Morphological analysis and pathological basis of the fine pulmonary reticulation at high-resolution CT

    International Nuclear Information System (INIS)

    Guan Chunshuang; Ma Daqing; Guan Yansheng; Chen Budong; Zhang Yansong

    2010-01-01

    Objective: To study the morphological appearance and pathological basis of the fine pulmonary reticulation at HRCT. Methods: One hundred and seven patients were analyzed about the morphology findings and dynamic changes on pulmonary HRCT. Twenty-four coal worker's pneumoconiosis (CWP) specimens were examined to make comparison between CT and pathology. The data was analyzed by using the Chi-square test. Results: The reticular gap was less than 3 mm in diameter. The morphology of reticulation was round or irregular. Pulmonary parenchyma was seen between the gaps. The reticular wall was smooth or coarse. The thickness was less than 1 mm. One hundred and seven patients had accompanying signs including ground-glass opacity (68.2%, 73 patients), crazy paving (23.4%, 25 patients), interlobular septal thickening (84.1%, 90 patients), emphysema (32.7%, 35 patients), interface sign (58.9%, 63 patients), traction bronchiolectasis (41.1%, 44 patients) and honeycombing (26.2%, 28 patients). The differences of the honeycomb, traction bronchiolectosis, interbobular septal thickening, interface sign and paving were statistically significant between the fibrotic group and pneunonia (P <0.01). Pneumonia showed extensive area of ground-glass opacity (GGO) with fine reticulation. Fine reticculation with both interlobular septal thickening and small nodules were observed more frequently in lmphangitic carcinomatosis. Idiopathic pulmonary fibrosis (IPF) showed fine reticulation among the honeycombing. Connective tissue disease (CTD) showed fine reticulation with rarely honeycombing and it could be partly absorbed. Fine reticulation with emphysema was seen in chronic bronchitis. In the 58 follow-up patients, the fine reticulation increased in 26 patients, decreased or disappeared in 22 patients and showed no change in 10 patients. The major pathological basis of the fine reticulation was intralobular interstitial thickening, including fibrosis hyperplasia, inflammatory cells and tumor

  4. CT pelvimetry

    International Nuclear Information System (INIS)

    Vicens, J.L.; Charles, G.; Le Berre, J.; Flageat, J.

    1989-01-01

    Pelvimetry aims at providing the obstetrician with information on the size and morphology of the female pelvis, thus enabling him to assess the obstetrical prognosis as accurately as possible. Computed tomography (CT) has several advantages, in particular the lower mother and fetus radiation dose. After a brief description of obstetrical anatomy, the usual CT exploration method is presented and its results are considered in terms of measurements, indices and morphological findings. If performed with a very strict exploration procedure, CT pelvimetry is a very reliable, fact and comfortable method of examination. All these advantages, combined with the minimized patient dose, should lead to an increasingly widespread use of this technique [fr

  5. Dual-energy CT in vertebral compression fractures: performance of visual and quantitative analysis for bone marrow edema demonstration with comparison to MRI

    International Nuclear Information System (INIS)

    Bierry, Guillaume; Venkatasamy, Aina; Kremer, Stephane; Dosch, Jean-Claude; Dietemann, Jean-Louis

    2014-01-01

    To prospectively evaluate the performance of virtual non-calcium (VNC) dual-energy CT (DECT) images for the demonstration of trauma-related abnormal marrow attenuation in collapsed and non-collapsed vertebral compression fractures (VCF) with MRI as a reference standard. Twenty patients presenting with non-tumoral VCF were consecutively and prospectively included in this IRB-approved study, and underwent MRI and DECT of the spine. MR examination served as a reference standard. Two independent readers visually evaluated all vertebrae for abnormal marrow attenuation (''CT edema'') on VNC DECT images; specificity, sensitivity, predictive values, intra and inter-observer agreements were calculated. A last reader performed a quantitative evaluation of CT numbers; cut-off values were calculated using ROC analysis. In the visual analysis, VNC DECT images had an overall sensitivity of 84 %, specificity of 97 %, and accuracy of 95 %, intra- and inter-observer agreements ranged from k = 0.74 to k = 0.90. CT numbers were significantly different between vertebrae with edema on MR and those without (p < 0.0001). Cut-off values provided sensitivity of 85 % (77 %) and specificity of 82 % (74 %) for ''CT edema'' on thoracic (lumbar) vertebrae. VNC DECT images allowed an accurate demonstration of trauma-related abnormal attenuation in VCF, revealing the acute nature of the fracture, on both visual and quantitative evaluation. (orig.)

  6. Dual-energy CT in vertebral compression fractures: performance of visual and quantitative analysis for bone marrow edema demonstration with comparison to MRI

    Energy Technology Data Exchange (ETDEWEB)

    Bierry, Guillaume; Venkatasamy, Aina; Kremer, Stephane; Dosch, Jean-Claude; Dietemann, Jean-Louis [University Hospital of Strasbourg, Department of Radiology, Strasbourg (France)

    2014-04-15

    To prospectively evaluate the performance of virtual non-calcium (VNC) dual-energy CT (DECT) images for the demonstration of trauma-related abnormal marrow attenuation in collapsed and non-collapsed vertebral compression fractures (VCF) with MRI as a reference standard. Twenty patients presenting with non-tumoral VCF were consecutively and prospectively included in this IRB-approved study, and underwent MRI and DECT of the spine. MR examination served as a reference standard. Two independent readers visually evaluated all vertebrae for abnormal marrow attenuation (''CT edema'') on VNC DECT images; specificity, sensitivity, predictive values, intra and inter-observer agreements were calculated. A last reader performed a quantitative evaluation of CT numbers; cut-off values were calculated using ROC analysis. In the visual analysis, VNC DECT images had an overall sensitivity of 84 %, specificity of 97 %, and accuracy of 95 %, intra- and inter-observer agreements ranged from k = 0.74 to k = 0.90. CT numbers were significantly different between vertebrae with edema on MR and those without (p < 0.0001). Cut-off values provided sensitivity of 85 % (77 %) and specificity of 82 % (74 %) for ''CT edema'' on thoracic (lumbar) vertebrae. VNC DECT images allowed an accurate demonstration of trauma-related abnormal attenuation in VCF, revealing the acute nature of the fracture, on both visual and quantitative evaluation. (orig.)

  7. Strong association of 677 C>T substitution in the MTHFR gene with male infertility--a study on an indian population and a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Nishi Gupta

    Full Text Available Methylenetetrahydrofolate reductase (MTHFR is an important enzyme of folate and methionine metabolism, making it crucial for DNA synthesis and methylation. The objective of this study was to analyze MTHFR gene 677C>T polymorphism in infertile male individuals from North India, followed by a meta-analysis on our data and published studies.We undertook genotyping on a total of 837 individuals including well characterized infertile (N = 522 and confirmed fertile (N = 315 individuals. The SNP was typed by direct DNA sequencing. Chi square test was done for statistical analysis. Published studies were searched using appropriate keywords. Source of data collection for meta-analysis included 'Pubmed', 'Ovid' and 'Google Scholar'. Those studies analyzing 677C>T polymorphism in male infertility and presenting all relevant data were included in meta-analysis. The genotype data for infertile subjects and fertile controls was extracted from each study. Chi square test was done to obtain odds ratio (OR and p-value. Meta-analysis was performed using Comprehensive Meta-analysis software (Version 2. The frequency of mutant (T allele (p = 0.0025 and genotypes (CT+TT (p = 0.0187 was significantly higher in infertile individuals in comparison to fertile controls in our case-control study. The overall summary estimate (OR for allele and genotype meta-analysis were 1.304 (p = 0.000, 1.310 (p = 0.000, respectively, establishing significant association of 677C>T polymorphism with male infertility.677C>T substitution associated strongly with male infertility in Indian population. Allele and genotype meta-analysis also supported its strong correlation with male infertility, thus establishing it as a risk factor.

  8. Size-based emphysema cluster analysis on low attenuation area in 3D volumetric CT: comparison with pulmonary functional test

    Science.gov (United States)

    Lee, Minho; Kim, Namkug; Lee, Sang Min; Seo, Joon Beom; Oh, Sang Young

    2015-03-01

    To quantify low attenuation area (LAA) of emphysematous regions according to cluster size in 3D volumetric CT data of chronic obstructive pulmonary disease (COPD) patients and to compare these indices with their pulmonary functional test (PFT). Sixty patients with COPD were scanned by a more than 16-multi detector row CT scanner (Siemens Sensation 16 and 64) within 0.75mm collimation. Based on these LAA masks, a length scale analysis to estimate each emphysema LAA's size was performed as follows. At first, Gaussian low pass filter from 30mm to 1mm kernel size with 1mm interval on the mask was performed from large to small size, iteratively. Centroid voxels resistant to the each filter were selected and dilated by the size of the kernel, which was regarded as the specific size emphysema mask. The slopes of area and number of size based LAA (slope of semi-log plot) were analyzed and compared with PFT. PFT parameters including DLco, FEV1, and FEV1/FVC were significantly (all p-value< 0.002) correlated with the slopes (r-values; -0.73, 0.54, 0.69, respectively) and EI (r-values; -0.84, -0.60, -0.68, respectively). In addition, the D independently contributed regression for FEV1 and FEV1/FVC (adjust R sq. of regression study: EI only, 0.70, 0.45; EI and D, 0.71, 0.51, respectively). By the size based LAA segmentation and analysis, we evaluated the Ds of area, number, and distribution of size based LAA, which would be independent factors for predictor of PFT parameters.

  9. Analysis of histological type and CT features on patients with haemoptysis in primary lung cancer

    International Nuclear Information System (INIS)

    Zhang Yixing; Huang Jinhuo

    2008-01-01

    Objective: To explore the CT features and histological types of haemoptysis patients with primary lung cancer. Methods: 50 haemoptysis patients (group A) with primary lung cancer confirmed by bronchoendoscopic examination or operation were analyzed. 50 cases of primary lung cancer without haemoptysis were studied as the contrast group (group B). The tumor size, shape, cavity, as well as location and pathological type were compared. Results: The proportions of adenocarcinoma and squamous cell carcinoma were 48%, 26% in Group A and 23%, 31% in Group B respectively. The occurrent rate of adenocarcinoma showed significant difference between Group A and B (P>0.05). The proportion of central lung cancer and peripheral lung cancer were 54%, 50% and 46%, 50% in Group A and B respectively. No significant difference occurred in both two types of cancer between two groups (P>0.05). The average size of cancer mass were 30±2.54 mm in Group A and 32±1.93mm in group B. The occurrence rate of lung cavity was 18% and 15% respectively in Group A and B. No significant difference existed in size and the occurrence rate of lung cancer mass between Group A and B (P>0.05). Conclusion: Haemoptysis in patients of primary lung cancer was correlated with pathology type, instead of location, size and cavities. (authors)

  10. CT findings and clinical analysis of subcortical hematomas in elderly patients

    International Nuclear Information System (INIS)

    Ueno, Yasushi; Tanaka, Akira; Yoshinaga, Shinya; Kimura, Masato

    1991-01-01

    Ten elderly patients (73-87 years, 78.4 years on the average) with subcortical hematomas were divided into two groups according to the shape of the hematoma on a CT scan: a lobulated group (6 patients) and a global group (4 patients). The lobulated group had a history of hypertension in one patient. The hematomas extended widely around the parietal lobe and were accompanied by perifocal edema, brain shifts and subarachnoid hemorrhages, deep consciousness disturbances, and poor prognosis of life and function. Amyloid depositions in the arteries around the hematomas were confirmed histologically in one patient. The global group had a history of hypertension in two patients. The hematomas were localized in the parietal, temporal, or occipital lobe without perifocal edema, brain shift and subarachnoid hemorrhages, and accompanied by mild consciousness disturbances. The life prognosis was good, but the functional prognosis was poor, with a subsequent development of dementia. A lobulated subcortical hematoma is thought to be due to amyloid angiopathy, while a global subcortical hematoma is thought to be due to hypertension. A surgical evacuation is seldom indicated for either type of subcortical hematoma in elderly patients. (author)

  11. 110 Subfascial lipomatous tumors. MR and CT findings versus histopathological diagnosis and cytogenetic analysis

    International Nuclear Information System (INIS)

    Einarsdottir, H.; Soederlund, V.; Larsson, O.; Mandahl, N.; Bauer, H.C.F.

    1999-01-01

    Purpose: To evaluate whether liposarcoma, atypical lipomatous tumors and lipoma can be differentiated radiologically. Material and Methods: We have retrospectively analyzed CT and/or MR images of 110 subfascial lipomatous lesions. The amount of fat within the tumors was visually graded from the images as: none, 1-75%, 75-95% or 95-100%. The structure of non-fatty tumor components was compared. The images were compared to histopathology and in 37 cases to cytogenetic findings. Results: Only 4 of 20 liposarcomas contained fat. All 4 lesions, histopathologically diagnosed as atypical lipomatous tumors, contained fat but less than 75% of tumor volume. All lesions with more fat than 75% of tumor volume were histologically diagnosed as lipomas. However, one-third of the karyotyped lipomas had ring chromosomes which are considered typical for atypical lipomatous tumors. Conclusion: When a tumor is composed more or less solely of fat, the diagnosis of a lipoma or atypical lipomatous tumor with a phenotype simulating a lipoma can be assumed. When the fat content is less than 75% of the tumor volume or non-fatty nodules are found, biopsies from different tumor components have to be performed to exclude malignancy. When no fat is found, imaging does not help in differentiating lipoma or liposarcoma from other soft tissue tumors. (orig.)

  12. Changes of the hip joints associated with chronic subluxation and dislocation: CT and plain radiography analysis

    International Nuclear Information System (INIS)

    Yang, Ik; Ryu, Kyung Nam; Lee, Sun Wha; Choi, Woo Suk; Lee, Eil Seong

    1993-01-01

    Secondary osteoarthritis of the hip joint is a common disease and is frequently followed by chronic subluxation and dislocation. Twenty four cases of the secondary osteoarthritis associated with chronic subluxation and dislocation of the hip joints were evaluated with plain radiography and computed tomography. We retrospectively analyzed 1) the osteoarthritis and calcification of the acetabular labrum, 2) the thickness of the quadrilateral plate of the ilium, and 3) anteroposterior diameter of the acetabulum. The changes of the hip joints in subluxation (n=14) revealed ossification of the acetabular labrum in 12 cases (86%), thickening of the quadrilateral plate of the ilium in 11 cases (78%) but anteroposterior diameter of the acetabulum was not changed. The changes of the hip joints in dislocation (n=10) revealed no evidence of the ossification of the acetabular labrum, thickening of the quadrilateral plate of the ilium in 10 cases (100%) and decreased anteroposterior diameter of the acetabulum. We conclude that CT findings of subluxation and dislocation of the hip joints can be helpful in the evaluation of the secondary osteoarthritis of the hip joints

  13. MicroCT analysis of calcium/phosphorus ratio maps at different bone sites

    International Nuclear Information System (INIS)

    Speller, R.; Pani, S.; Tzaphlidou, M.; Horrocks, J.

    2005-01-01

    The Ca/P ratio was measured in cortical bone samples from the femoral neck, front and rear tibia of rats, rabbits and lambs using synchrotron microCT. Use of a monoenergetic X-ray beam, as provided by the synchrotron facility, generates accurate 3-D maps of the linear attenuation coefficient within the sample and hence gives the ability to map different chemical components. Data were taken at 20keV for each bone sample and calibration phantoms. From the 3-D data sets, multiple 2-D slices were reconstructed with a slice thickness of ∼28μm and converted to Ca/P ratios using the calibration phantom results. Average values for each animal and bone site were estimated. Differences between the same bone sites from different animals are not significant (0.3 -3 ) demonstrating a dependence upon lifestyle and bone use. The spatial distribution of Ca/P was found to be non-uniform for some bones and some animals possibly indicating the structural mechanism for obtaining bone strength

  14. MicroCT analysis of calcium/phosphorus ratio maps at different bone sites

    Energy Technology Data Exchange (ETDEWEB)

    Speller, R. [Medical Physics and Bioengineering Department, UCL, London, WC1E 6BT (United Kingdom)]. E-mail: rspeller@medphys.ucl.ac.uk; Pani, S. [Department of Physics, University of Trieste (Italy); Tzaphlidou, M. [Lab Medical Physics, Medical School, University of Ioannina, 45110 Ioannina (Greece); Horrocks, J. [Clinical Physics Group, St Bartholomew' s Hospital, London, EC1A 6BT (United Kingdom)

    2005-08-11

    The Ca/P ratio was measured in cortical bone samples from the femoral neck, front and rear tibia of rats, rabbits and lambs using synchrotron microCT. Use of a monoenergetic X-ray beam, as provided by the synchrotron facility, generates accurate 3-D maps of the linear attenuation coefficient within the sample and hence gives the ability to map different chemical components. Data were taken at 20keV for each bone sample and calibration phantoms. From the 3-D data sets, multiple 2-D slices were reconstructed with a slice thickness of {approx}28{mu}m and converted to Ca/P ratios using the calibration phantom results. Average values for each animal and bone site were estimated. Differences between the same bone sites from different animals are not significant (0.3

  15. Post-operative cyst and orbital walls. A CT image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fukuta, Masahiro (Takeda General Hospital, Aizuwakamatsu, Fukushima (Japan)); Iinuma, Toshitaka

    1989-07-01

    A set of coronal CT images obtained by 118 sides (109 cases) of post-operative cysts of maxilla, seen from 1982 to 1988, was analyzed as to the orbital wall affections. Coronal images were grouped into five consecutive planes, i.e. the first plane being the one which is 5 mm posterior to the nasion, and the other planes in successive orders each being 5 mm apart. The orbital walls were classified into inferior, medial, and transition of these two. The orbital wall affections were classified into dehiscence, thinned-out (less than 1 mm), and normal. The orbital signs and symptoms (epiphora, pain, asthenopia, visual loss, diplopia, and exophthalmos) were analyzed based upon the questionnaires by patients. The inferior wall affections (dehiscence and thinned-out) were seen most often (57%) at the third plane (2 cm posterior to the nasion). The orbital signs and symptoms in general were seen in half of the cases of which 20% were of grave (visual loss, diplopia and exophthalmos). These signs and symptoms were the more often, the more anterior the site of affections located. Grave signs and symptoms were seen at 2 to 2.5 cm posterior to the nasion when the orbital floor was affected and the inferior rectus were either pushed up or in direct contact with the cysts. (author).

  16. In vivo micro-CT analysis of bone remodeling in a rat calvarial defect model

    Science.gov (United States)

    Umoh, Joseph U.; Sampaio, Arthur V.; Welch, Ian; Pitelka, Vasek; Goldberg, Harvey A.; Underhill, T. Michael; Holdsworth, David W.

    2009-04-01

    The rodent calvarial defect model is commonly used to investigate bone regeneration and wound healing. This study presents a micro-computed tomography (micro-CT) methodology for measuring the bone mineral content (BMC) in a rat calvarial defect and validates it by estimating its precision error. Two defect models were implemented. A single 6 mm diameter defect was created in 20 rats, which were imaged in vivo for longitudinal experiments. Three 5 mm diameter defects were created in three additional rats, which were repeatedly imaged ex vivo to determine precision. Four control rats and four rats treated with bone morphogenetic protein were imaged at 3, 6, 9 and 12 weeks post-surgery. Scan parameters were 80 kVp, 0.45 mA and 180 mAs. Images were reconstructed with an isotropic resolution of 45 µm. At 6 weeks, the BMC in control animals (4.37 ± 0.66 mg) was significantly lower (p small BMC changes in animals.

  17. The value of emergency CT studies in spontaneous rupture of hepatocellular carcinoma. Analysis for tumor protrusion and hemorrhagic ascites

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, Makiko; Kobayashi, Hisashi; Ichikawa, Taro; Cho, Keiichi; Gemma, Kazuhito; Kumazaki, Tatsuo [Nippon Medical School, Tokyo (Japan)

    1997-12-01

    CT characteristics of spontaneous rupture of HCC (n=13) were reviewed retrospectively, and the value of emergency CT studies in this disease was evaluated. Especially, tumor protrusion ratio (TPR) and ascitic CT numbers were measured to for comparison with the data for unruptured HCCs and ordinary, (e.g., non-hemorrhagic) ascites (n=13). As a result, except for diffuse type HCCs, the TPR was significantly higher than for the unruptured HCCs. Nine cases had intraperitoneal HDAs, and the laterality of the HDAs corresponded with that of the ruptured tumors in 8 cases. Also, the ascitic CT numbers apart from the HDA were still higher than the ordinary ascites. Therefore, a high TPR, HDAs adjacent to the tumor, and elevated ascitic CT numbers are important CT manifestations indicating HCC rupture. Diffuse HCCs, however, require careful clinical evaluation. (author)

  18. The value of emergency CT studies in spontaneous rupture of hepatocellular carcinoma. Analysis for tumor protrusion and hemorrhagic ascites

    International Nuclear Information System (INIS)

    Ishihara, Makiko; Kobayashi, Hisashi; Ichikawa, Taro; Cho, Keiichi; Gemma, Kazuhito; Kumazaki, Tatsuo

    1997-01-01

    CT characteristics of spontaneous rupture of HCC (n=13) were reviewed retrospectively, and the value of emergency CT studies in this disease was evaluated. Especially, tumor protrusion ratio (TPR) and ascitic CT numbers were measured to for comparison with the data for unruptured HCCs and ordinary, (e.g., non-hemorrhagic) ascites (n=13). As a result, except for diffuse type HCCs, the TPR was significantly higher than for the unruptured HCCs. Nine cases had intraperitoneal HDAs, and the laterality of the HDAs corresponded with that of the ruptured tumors in 8 cases. Also, the ascitic CT numbers apart from the HDA were still higher than the ordinary ascites. Therefore, a high TPR, HDAs adjacent to the tumor, and elevated ascitic CT numbers are important CT manifestations indicating HCC rupture. Diffuse HCCs, however, require careful clinical evaluation. (author)

  19. CT Scan

    Science.gov (United States)

    ... disease, lung nodules and liver masses Monitor the effectiveness of certain treatments, such as cancer treatment Detect ... scan done in a hospital or an outpatient facility. CT scans are painless and, with newer machines, ...

  20. Thoracic CT

    Science.gov (United States)

    ... through a vein (IV) in your hand or forearm. It may be given through the rectum using ... CT scan Vertebra, thoracic (mid back) Normal lung anatomy Thoracic organs References Gotway MB, Panse PM, Gruden ...

  1. CT Enterography

    Science.gov (United States)

    ... a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. These ... other medical conditions, and if you have a history of heart disease, asthma, diabetes, kidney disease or ...

  2. Evaluating PET-CT in routine surveillance and follow-up after treatment for cervical cancer: a cost-effectiveness analysis.

    Science.gov (United States)

    Auguste, P; Barton, P; Meads, C; Davenport, C; Małysiak, S; Kowalska, M; Zapalska, A; Guest, P; Martin-Hirsch, P; Borowiack, E; Khan, K; Sundar, S; Roberts, T

    2014-03-01

    To undertake a cost-effectiveness analysis that compares positron emission tomography - computed tomography (PET-CT) imaging plus standard practice with standard practice alone in the diagnosis of recurrent or persistent cervical cancer during routine surveillance and follow-up of women who have previously been diagnosed and treated. Model-based economic evaluation using data from a systematic review, supplemented with data from other sources, and taking a UK National Health Service (NHS) perspective. Secondary Care in England. Women at least 3 months after the completion of treatment, with either recurrent or persistent cervical cancer. A state transition (Markov) model was developed using TreeAge Pro 2011. The structure of the model was informed by the reviews of the trials and clinical input. In the model, two diagnostic strategies were examined. A one-way sensitivity analysis, probabilistic sensitivity analysis, and a value of information analysis were also carried out. Cost-effectiveness based on incremental cost per quality-adjusted life year (QALY). Adding PET-CT to the current treatment strategy of clinical examination and scanning [magnetic resonance imaging (MRI) and/or CT scan] during the routine surveillance and follow-up of women with recurrent or persistent cervical cancer is significantly more costly, with only a minimal increase in effectiveness. The incremental cost-effectiveness ratio (ICER) for the strategy of PET-CT as an adjunct to the standard treatment strategy that included clinical examination, MRI, and/or CT scan, compared with the usual treatment alone, was over £1 million per QALY. The results of the current analysis suggest that use of PET-CT in the diagnosis of recurrent or persistent cervical cancer is not cost-effective. Current guidelines recommending imaging using PET-CT as a diagnostic or surveillance tool need to be reconsidered in light of these results. This study did not specifically investigate the use of PET-CT in women

  3. Computerized detection of noncalcified plaques in coronary CT angiography: Evaluation of topological soft gradient prescreening method and luminal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Jun, E-mail: jvwei@umich.edu; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella [Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-08-15

    Purpose: The buildup of noncalcified plaques (NCPs) that are vulnerable to rupture in coronary arteries is a risk for myocardial infarction. Interpretation of coronary CT angiography (cCTA) to search for NCP is a challenging task for radiologists due to the low CT number of NCP, the large number of coronary arteries, and multiple phase CT acquisition. The authors conducted a preliminary study to develop machine learning method for automated detection of NCPs in cCTA. Methods: With IRB approval, a data set of 83 ECG-gated contrast enhanced cCTA scans with 120 NCPs was collected retrospectively from patient files. A multiscale coronary artery response and rolling balloon region growing (MSCAR-RBG) method was applied to each cCTA volume to extract the coronary arterial trees. Each extracted vessel was reformatted to a straightened volume composed of cCTA slices perpendicular to the vessel centerline. A topological soft-gradient (TSG) detection method was developed to prescreen for NCP candidates by analyzing the 2D topological features of the radial gradient field surface along the vessel wall. The NCP candidates were then characterized by a luminal analysis that used 3D geometric features to quantify the shape information and gray-level features to evaluate the density of the NCP candidates. With machine learning techniques, useful features were identified and combined into an NCP score to differentiate true NCPs from false positives (FPs). To evaluate the effectiveness of the image analysis methods, the authors performed tenfold cross-validation with the available data set. Receiver operating characteristic (ROC) analysis was used to assess the classification performance of individual features and the NCP score. The overall detection performance was estimated by free response ROC (FROC) analysis. Results: With our TSG prescreening method, a prescreening sensitivity of 92.5% (111/120) was achieved with a total of 1181 FPs (14.2 FPs/scan). On average, six features

  4. Computerized detection of noncalcified plaques in coronary CT angiography: Evaluation of topological soft gradient prescreening method and luminal analysis

    International Nuclear Information System (INIS)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella

    2014-01-01

    Purpose: The buildup of noncalcified plaques (NCPs) that are vulnerable to rupture in coronary arteries is a risk for myocardial infarction. Interpretation of coronary CT angiography (cCTA) to search for NCP is a challenging task for radiologists due to the low CT number of NCP, the large number of coronary arteries, and multiple phase CT acquisition. The authors conducted a preliminary study to develop machine learning method for automated detection of NCPs in cCTA. Methods: With IRB approval, a data set of 83 ECG-gated contrast enhanced cCTA scans with 120 NCPs was collected retrospectively from patient files. A multiscale coronary artery response and rolling balloon region growing (MSCAR-RBG) method was applied to each cCTA volume to extract the coronary arterial trees. Each extracted vessel was reformatted to a straightened volume composed of cCTA slices perpendicular to the vessel centerline. A topological soft-gradient (TSG) detection method was developed to prescreen for NCP candidates by analyzing the 2D topological features of the radial gradient field surface along the vessel wall. The NCP candidates were then characterized by a luminal analysis that used 3D geometric features to quantify the shape information and gray-level features to evaluate the density of the NCP candidates. With machine learning techniques, useful features were identified and combined into an NCP score to differentiate true NCPs from false positives (FPs). To evaluate the effectiveness of the image analysis methods, the authors performed tenfold cross-validation with the available data set. Receiver operating characteristic (ROC) analysis was used to assess the classification performance of individual features and the NCP score. The overall detection performance was estimated by free response ROC (FROC) analysis. Results: With our TSG prescreening method, a prescreening sensitivity of 92.5% (111/120) was achieved with a total of 1181 FPs (14.2 FPs/scan). On average, six features

  5. Use of CT-guided fine needle aspiration biopsy in epidermal growth factor receptor mutation analysis in patients with advanced lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Yi-Ping; Wang, Hai-Yan; Zhang, Jin; Feng, Yong (Dept. of Radiology, Jiangsu Cancer Inst. and Hospital, Nanjing, Jiangsu (China)), email: yipingzhuang2010@sina.com; Shi, Mei-Qi (Dept. of Chemotherapy, Jiangsu Cancer Inst. and Hospital, Nanjing, Jiangsu (China))

    2011-12-15

    Background. The safety of using a cutting needle when performing a core-needle biopsy is of major concern, in particular for small lung tumors or tumors near the hilum. Purpose. To investigate the usefulness of CT-guided fine needle aspiration biopsy (FNAB) of the lung in obtaining tumor tissue for epidermal growth factor receptor (EGFR) mutation analysis in advanced lung cancer patients. Material and Methods. Forty-three patients with stage IIIB-IV lung cancer were enrolled. In all patients, CT-guided FNAB was performed using an 18-gauge or 20-gauge Chiba aspiration needle for histology diagnosis and EGFR mutation analysis. Complications associated with CT-guided FNAB were observed, and the specimen mutational assessments were recorded. Results. The obtained tumor samples ranged from 0.5-1.5 cm in length and were adequate for histological and DNA analyses in all patients. No patient had a pneumothorax or hemoptysis. Minor needle tract bleeding appeared in eight patients. Mutation analysis was satisfactorily demonstrated in 23 mutations and 20 non-mutations. Ten and 13 mutations were identified by 18-gauge and 20-gauge needle biopsies, respectively. EFGR mutations, including 12 cases of EGFR exon 19 deletion and 11 cases of exon 21 point mutation, were present in 21 patients with adenocarcinomas, one with squamous cell carcinoma, and one with undifferentiated carcinoma. Conclusion. CT-guided FNAB is a feasible and safe technique for obtaining lung tumor tissues for EGFR gene mutation analysis

  6. Skull shape differentiation of black and white olms (Proteus anguinus anguinus and Proteus a. parkelj): an exploratory analysis with micro-CT scanning

    NARCIS (Netherlands)

    Ivanović, A.; Aljančič, G.; Artzen, J.W.

    2013-01-01

    We performed an exploratory analysis of the morphology of the cranium in the white olm (Proteus anguinus anguinus) and the black olm (P. a. parkelj) with micro-CT scanning and geometric morphometrics. The mudpuppy (Necturus maculosus) was used as an outgroup. The black olm falls outside the white

  7. Validation of plaster endocast morphology through 3D CT image analysis.

    Science.gov (United States)

    Schoenemann, P Thomas; Gee, James; Avants, Brian; Holloway, Ralph L; Monge, Janet; Lewis, Jason

    2007-02-01

    A crucial component of research on brain evolution has been the comparison of fossil endocranial surfaces with modern human and primate endocrania. The latter have generally been obtained by creating endocasts out of rubber latex shells filled with plaster. The extent to which the method of production introduces errors in endocast replicas is unknown. We demonstrate a powerful method of comparing complex shapes in 3-dimensions (3D) that is broadly applicable to a wide range of paleoanthropological questions. Pairs of virtual endocasts (VEs) created from high-resolution CT scans of corresponding latex/plaster endocasts and their associated crania were rigidly registered (aligned) in 3D space for two Homo sapiens and two Pan troglodytes specimens. Distances between each cranial VE and its corresponding latex/plaster VE were then mapped on a voxel-by-voxel basis. The results show that between 79.7% and 91.0% of the voxels in the four latex/plaster VEs are within 2 mm of their corresponding cranial VEs surfaces. The average error is relatively small, and variation in the pattern of error across the surfaces appears to be generally random overall. However, inferior areas around the cranial base and the temporal poles were somewhat overestimated in both human and chimpanzee specimens, and the area overlaying Broca's area in humans was somewhat underestimated. This study gives an idea of the size of possible error inherent in latex/plaster endocasts, indicating the level of confidence we can have with studies relying on comparisons between them and, e.g., hominid fossil endocasts. Copyright 2006 Wiley-Liss, Inc.

  8. Planar strain analysis of liver undergoing microwave thermal ablation using x-ray CT.

    Science.gov (United States)

    Weiss, Noam; Goldberg, S Nahum; Nissenbaum, Yitzhak; Sosna, Jacob; Azhari, Haim

    2015-01-01

    To study the planar strain effects in liver during microwave (MW) thermal ablation as a means for tracking tissue expansion and contraction as a method for improving ablation monitoring. 1.4 mm circular metallic markers were inserted into 16 ex-vivo bovine fresh liver specimens, that were subsequently ablated (with the markers inside the specimen) by 40 W of microwave energy, for 1, 2, 3, 6, and 10 min. The markers were tracked during the ablation using an x-ray CT scanner. Images were acquired every 5-10 s enabling determination of the markers' coordinates over time. The 2D principal strains were calculated for triangles formed by subgroups of three markers, and their planar strain index, Ω, was plotted vs time. In addition, the radial distance of the markers from the antenna was measured at the end of each ablation. Subsequently, the tissue was sliced parallel to the imaged planes and the ablation zone was traced and digitized. The average ablation radius was then computed and compared to the radial distance. The planar strain, Ω(t), profile demonstrated an ascending pattern until reaching a maximum at about 180 s, with a mean peak value (Ω = 1.31 ± 0.04) indicating tissue expansion. Thereafter, Ω progressively declined over the remaining duration of the ablation treatment, indicating tissue contraction. Furthermore, when plotting the ablation size vs time and the markers' mean radial distance vs time, it was found that the two curves intercepted at a time corresponding to the time of peak planar strain. By detecting the point of maximal planar strain in tissues during MW application, it is possible to noninvasively identify the location of the ablation zone front. The fact that the liver tissue proximal to the ablated zone expands during the first part of the treatment and then contracts when the ablation front reaches it, may serve as an index for monitoring the thermal treatment.

  9. Comparison of demons deformable registration-based methods for texture analysis of serial thoracic CT scans

    Science.gov (United States)

    Cunliffe, Alexandra R.; Al-Hallaq, Hania A.; Fei, Xianhan M.; Tuohy, Rachel E.; Armato, Samuel G.

    2013-02-01

    To determine how 19 image texture features may be altered by three image registration methods, "normal" baseline and follow-up computed tomography (CT) scans from 27 patients were analyzed. Nineteen texture feature values were calculated in over 1,000 32x32-pixel regions of interest (ROIs) randomly placed in each baseline scan. All three methods used demons registration to map baseline scan ROIs to anatomically matched locations in the corresponding transformed follow-up scan. For the first method, the follow-up scan transformation was subsampled to achieve a voxel size identical to that of the baseline scan. For the second method, the follow-up scan was transformed through affine registration to achieve global alignment with the baseline scan. For the third method, the follow-up scan was directly deformed to the baseline scan using demons deformable registration. Feature values in matched ROIs were compared using Bland- Altman 95% limits of agreement. For each feature, the range spanned by the 95% limits was normalized to the mean feature value to obtain the normalized range of agreement, nRoA. Wilcoxon signed-rank tests were used to compare nRoA values across features for the three methods. Significance for individual tests was adjusted using the Bonferroni method. nRoA was significantly smaller for affine-registered scans than for the resampled scans (p=0.003), indicating lower feature value variability between baseline and follow-up scan ROIs using this method. For both of these methods, however, nRoA was significantly higher than when feature values were calculated directly on demons-deformed followup scans (p<0.001). Across features and methods, nRoA values remained below 26%.

  10. CT enterography in obscure gastrointestinal bleeding: a systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Wang, Zhen; Chen, Jun-qiang; Liu, Jin-lu; Qin, Xin-gan; Huang, Yuan

    2013-01-01

    The objective of this article is to provide a comprehensive and update overview of clinical application of CT enterography (CTE) in the evaluation of obscure gastrointestinal bleeding (OGIB). We performed a systematic review of relevant literatures in PubMed, EMBASE and The Cochrane Library and pooled the yield of CTE and the incremental yield (IY) of CTE over an alternate modality. A total of 18 studies (n=660) reported the yield of CTE in evaluating OGIB and the pooled yield was 40% (95% confidence interval (CI): 33–49%). Seven studies (n=279) compared the yield of CTE with capsule endoscopy (CE). The yield for CTE and CE for all findings was 34% and 53%, respectively (IY=−19%, 95% CI=−34% to −4%). When considering the types of identified lesions, the yield was significantly different for vascular and inflammatory lesions but not significantly different for neoplastic or other lesions. Two studies (n=63) compared the yield of CTE with double-balloon enteroscopy (DBE). The yield for CTE and DBE was 38% and 78%, respectively (IY=−40%, 95% CI=−55% to −25%). Three studies (n=49) compared the yield of CTE with digital subtraction angiography. The yield for CTE and digital subtraction angiography was 64% and 60%, respectively (IY=4%, 95% CI=−40% to 47%). CTE is an excellent diagnostic tool in patients with OGIB. It may play a complementary role to CE and can be used as a triage tool prior to DBE in evaluating OGIB.

  11. Constant strain rate and peri-implant bone modeling: an in vivo longitudinal micro-CT analysis.

    Science.gov (United States)

    De Smet, Els; Jaecques, Siegfried V N; Wevers, Martine; Sloten, Jos Vander; Naert, Ignace E

    2013-06-01

    Strain, frequency, loading time, and strain rate, among others, determine mechanical parameters in osteogenic loading. We showed a significant osteogenic effect on bone mass (BM) by daily peri-implant loading at 1.600µε.s(-1) after 4 weeks. To study the peri-implant osteogenic effect of frequency and strain in the guinea pig tibia by in vivo longitudinal micro-computed tomography (CT) analysis. One week after implant installation in both hind limb tibiae, one implant was loaded daily for 10' during 4 weeks, while the other served as control. Frequencies (3, 10, and 30Hz) and strains varied alike in the three series to keep the strain rate constant at 1.600µε.s(-1) . In vivo micro-CT scans were taken of both tibiae: 1 week after implantation but before loading (v1) and after 2 (v2) and 4 weeks (v3) of loading as well as postmortem (pm). BM (BM (%) bone-occupied area fraction) was calculated as well as the difference between test and control sides (delta BM) RESULTS: All implants (n=78) were clinically stable at 4 weeks. Significant increase in BM was measured between v1 and v2 (pimplant marrow 500 Region of Interest already 2 weeks after loading (p=.01) and was significantly larger (11%) in series 1 compared with series 2 (p=.006) and 3 (p=.016). Within the constraints of constant loading time and strain rate, the effect of early implant loading on the peri-implant bone is strongly dependent on strain and frequency. This cortical bone model has shown to be most sensitive for high force loading at low frequency. © 2011 Wiley Periodicals, Inc.

  12. 4D-SPECT/CT in orthopaedics: a new method of combined quantitative volumetric 3D analysis of SPECT/CT tracer uptake and component position measurements in patients after total knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Rasch, Helmut; Falkowski, Anna L.; Forrer, Flavio [Kantonsspital Baselland, Institute for Radiology and Nuclear Medicine, Bruderholz (Switzerland); Henckel, Johann [Imperial College London, London (United Kingdom); Hirschmann, Michael T. [Kantonsspital Baselland, Department of Orthopaedic Surgery and Traumatology, Bruderholz (Switzerland)

    2013-09-15

    The purpose was to evaluate the intra- and inter-observer reliability of combined quantitative 3D-volumetric single-photon emission computed tomography (SPECT)/CT analysis including size, intensity and localisation of tracer uptake regions and total knee arthroplasty (TKA) position. Tc-99m-HDP-SPECT/CT of 100 knees after TKA were prospectively analysed. The anatomical areas represented by a previously validated localisation scheme were 3D-volumetrically analysed. The maximum intensity was recorded for each anatomical area. Ratios between the respective value and the mid-shaft of the femur as the reference were calculated. Femoral and tibial TKA position (varus-valgus, flexion-extension, internal rotation- external rotation) were determined on 3D-CT. Two consultant radiologists/nuclear medicine physicians interpreted the SPECT/CTs twice with a 2-week interval. The inter- and intra-observer reliability was determined (ICCs). Kappa values were calculated for the area with the highest tracer uptake between the observers. The measurements of tracer uptake intensity showed excellent inter- and intra-observer reliabilities for all regions (tibia, femur and patella). Only the tibial shaft area showed ICCs <0.89. The kappa values were almost perfect (0.856, p < 0.001; 95 % CI 0.778, 0.922). For measurements of the TKA position, there was strong agreement within and between the readings of the two observers; the ICCs for the orientation of TKA components for inter- and intra-observer reliability were nearly perfect (ICCs >0.84). This combined 3D-volumetric standardised method of analysing the location, size and the intensity of SPECT/CT tracer uptake regions (''hotspots'') and the determination of the TKA position was highly reliable and represents a novel promising approach to biomechanics. (orig.)

  13. CT coronary angiography: impact of adapted statistical iterative reconstruction (ASIR) on coronary stenosis and plaque composition analysis.

    Science.gov (United States)

    Fuchs, Tobias A; Fiechter, Michael; Gebhard, Cathérine; Stehli, Julia; Ghadri, Jelena R; Kazakauskaite, Egle; Herzog, Bernhard A; Husmann, Lars; Gaemperli, Oliver; Kaufmann, Philipp A

    2013-03-01

    To assess the impact of adaptive statistical iterative reconstruction (ASIR) on coronary plaque volume and composition analysis as well as on stenosis quantification in high definition coronary computed tomography angiography (CCTA). We included 50 plaques in 29 consecutive patients who were referred for the assessment of known or suspected coronary artery disease (CAD) with contrast-enhanced CCTA on a 64-slice high definition CT scanner (Discovery HD 750, GE Healthcare). CCTA scans were reconstructed with standard filtered back projection (FBP) with no ASIR (0 %) or with increasing contributions of ASIR, i.e. 20, 40, 60, 80 and 100 % (no FBP). Plaque analysis (volume, components and stenosis degree) was performed using a previously validated automated software. Mean values for minimal diameter and minimal area as well as degree of stenosis did not change significantly using different ASIR reconstructions. There was virtually no impact of reconstruction algorithms on mean plaque volume or plaque composition (e.g. soft, intermediate and calcified component). However, with increasing ASIR contribution, the percentage of plaque volume component between 401 and 500 HU decreased significantly (p ASIR, which has been developed for noise reduction in latest high resolution CCTA scans, can be used reliably without interfering with the plaque analysis and stenosis severity assessment.

  14. Nondestructive Analysis of Apollo Samples by Micro-CT and Micro-XRF Analysis: A PET Style Examination

    Science.gov (United States)

    Zeigler, Ryan A.

    2014-01-01

    An integral part of any sample return mission is the initial description and classification of returned samples by the preliminary examination team (PET). The goal of a PET is to characterize and classify the returned samples, making this information available to the general research community who can then conduct more in-depth studies on the samples. A PET strives to minimize the impact their work has on the sample suite, which often limits the PET work to largely visual measurements and observations like optical microscopy. More modern techniques can also be utilized by future PET to nondestructively characterize astromaterials in a more rigorous way. Here we present our recent analyses of Apollo samples 14321 and 14305 by micro-CT and micro-XRF (respectively), assess the potential for discovery of "new" Apollo samples for scientific study, and evaluate the usefulness of these techniques in future PET efforts.

  15. Variability in "1"8F-FDG PET/CT methodology of acquisition, reconstruction and analysis for oncologic imaging: state survey

    International Nuclear Information System (INIS)

    Fischer, Andreia C.F. da S.; Druzian, Aline C.; Bacelar, Alexandre; Pianta, Diego B.; Silva, Ana M. Marques da

    2016-01-01

    The SUV in "1"8F-FDG PET/CT oncological imaging is useful for cancer diagnosis, staging and treatment assessment. There are, however, several factors that can give rise to bias in SUV measurements. When using SUV as a diagnostic tool, one needs to minimize the variability in this measurement by standardization of patient preparation, acquisition and reconstruction parameters. The aim of this study is to evaluate the methodological variability in PET/CT acquisition in Rio Grande do Sul State. For that, in each department, a questionnaire was applied to survey technical information from PET/CT systems and about the acquisitions and analysis methods utilized. All departments implement quality assurance programs consistent with (inter)national recommendations. However, the acquisition and reconstruction methods of acquired PET data differ. The implementation of a harmonized strategy for quantifying the SUV is suggested, in order to obtain greater reproducibility and repeatability. (author)

  16. Review Paper: Association of Transforming Growth Factor Beta-1 -509C/T Gene Polymorphism with Ischemic Stroke: A Meta Analysis

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar

    2016-05-01

    Full Text Available Introduction: Transforming Growth Factor-Beta 1 (TGF-β1 is a pleiotropic cytokine with potent anti-inflammatory property, which has been considered as an essential risk factor in the inflammatory process of Ischemic Stroke (IS, by involving in the pathophysiological progression of hypertension, atherosclerosis, and lipid metabolisms. -509C/T TGF-β1 gene polymorphism has been found to be associated with the risk of IS. The aim of this meta-analysis was to provide a relatively comprehensive account of the relation between -509C/T gene polymorphisms of TGF-β1 and susceptibility to IS. Methods: A review of literature for eligible genetic association Studies published before October 20, 2014 was conducted in the PubMed, EMBASE, Google Scholar and Trip database. The strength of association was calculated by pooled odds ratios (ORs with 95% confidence intervals using RevMan 5.3 software. Heterogeneity was examined using Higgins I-squared, Tau-squared, and Chi-squared tests. Results: A total of 2 studies involving 614 cases and 617 controls were found. The overall estimates did not show any significant relation between TGF-β1-509C/T polymorphism and risk of IS under dominant (CC+CT vs. TT: OR=1.01, 95%CI=0.31 to 3.26; P=0.99, recessive (CC vs. CT+TT: OR=0.94, 95%CI=0.47 to 1.90; P=0.87, and allelic models (T vs. C: OR=1.06, 95%CI=0.55 to 2.04; P=0.86. Conclusion: This meta-analysis showed that TGF-β1-509C/T gene polymorphism has no significant association with the susceptibility of IS. Further well-designed prospective studies with larger sample size are needed to confirm these findings.

  17. Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis.

    Directory of Open Access Journals (Sweden)

    Hirotsugu Ohkubo

    Full Text Available Although several computer-aided computed tomography (CT analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF, it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF.The purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF.A total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT, the normally attenuated lung volume as defined from -950 HU to -701 Hounsfield unit (NL, the volume of the whole lung (WL, and the percentage of NL to WL (NL%, were calculated.CT indices (MCT, WL, and NL closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC (r = 0.92, P <0.0001. NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF. Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI, 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05].The measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.

  18. A meta-analysis of 18FDG-PET–CT, 18FDG-PET, MRI and bone scintigraphy for diagnosis of bone metastases in patients with lung cancer

    International Nuclear Information System (INIS)

    Qu Xinhua; Huang Xiaolu; Yan Weili; Wu Lianming; Dai Kerong

    2012-01-01

    Background and purpose: Lung cancer is the most common cause of cancer related death among both men and women worldwide. The skeleton is the most common site of cancer metastasis. Early detection is crucial for prognosis. To evaluate and compare the capability for bone metastasis assessment of [ 18 F] fluoro-2-D-glucose positron emission tomography with computed tomography ( 18 FDG-PET–CT), [ 18 F] fluoro-2-D-glucose positron emission tomography ( 18 FDG-PET), magnetic resonance imaging (MRI) and bone scintigraphy (BS) in lung cancer patients, a meta-analysis is preformed. Methods: We searched MEDLINE, OVID, EMBASE and the Cochrane Library for studies evaluating diagnosis validity of 18 FDG-PET–CT, 18 FDG-PET, MRI and BS between January 1990 and August 2010. Meta-analysis methods were used to pool sensitivity, specificity, diagnostic odd ratios (DORs) and to construct a summary receiver-operating characteristic curve (SROC). Results: A total of 17 articles (9 18 FDG-PET–CT studies, 9 18 FDG-PET studies, 6 MRI studies and 16 BS studies) that included 2940 patients who fulfilled all of the inclusion criteria were considered for inclusion in the analysis. The pooled sensitivity for the detection of bone metastasis in lung cancer using 18 FDG-PET–CT, 18 FDG-PET, MRI and BS were 0.92 (95% CI, 0.88–0.95), 0.87 (95% CI, 0.81–0.92), 0.77 (95% CI, 0.65–0.87) and 0.86 (95% CI, 0.82–0.89), respectively. The pooled specificity for the detection of bone metastasis from lung cancer using 18 FDG-PET–CT, 18 FDG-PET, MRI and BS were 0.98 (95% CI, 0.97–0.98), 0.94 (95% CI, 0.92–0.96), 0.92 (95% CI, 0.88–0.95), 0.88 (95% CI, 0.86–0.89), respectively. The pooled DORs estimates for 18 FDG-PET–CT 449.17 were significantly higher than for 18 FDG-PET (118.25, P 18 FDG-PET–CT and 18 FDG-PET were better imaging methods for diagnosing bone metastasis from lung cancer than MRI and BS. 18 FDG-PET–CT has higher diagnostic value (sensitivity, specificity and DORs

  19. Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis.

    Science.gov (United States)

    Ohkubo, Hirotsugu; Kanemitsu, Yoshihiro; Uemura, Takehiro; Takakuwa, Osamu; Takemura, Masaya; Maeno, Ken; Ito, Yutaka; Oguri, Tetsuya; Kazawa, Nobutaka; Mikami, Ryuji; Niimi, Akio

    2016-01-01

    Although several computer-aided computed tomography (CT) analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF), it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF. The purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF. A total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR) CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology) staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT), the normally attenuated lung volume as defined from -950 HU to -701 Hounsfield unit (NL), the volume of the whole lung (WL), and the percentage of NL to WL (NL%), were calculated. CT indices (MCT, WL, and NL) closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC) (r = 0.92, P <0.0001). NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF. Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI), 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05]). The measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.

  20. Effects of organ motion on proton prostate treatments, as determined from analysis of daily CT imaging for patient positioning.

    Science.gov (United States)

    Maeda, Yoshikazu; Sato, Yoshitaka; Shibata, Satoshi; Bou, Sayuri; Yamamoto, Kazutaka; Tamamura, Hiroyasu; Fuwa, Nobukazu; Takamatsu, Shigeyuki; Sasaki, Makoto; Tameshige, Yuji; Kume, Kyo; Minami, Hiroki; Saga, Yusuke; Saito, Makoto

    2018-05-01

    We quantified interfractional movements of the prostate, seminal vesicles (SVs), and rectum during computed tomography (CT) image-guided proton therapy for prostate cancer and studied the range variation in opposed lateral proton beams. We analyzed 375 sets of daily CT images acquired throughout the proton therapy treatment of ten patients. We analyzed daily movements of the prostate, SVs, and rectum by simulating three image-matching strategies: bone matching, prostate center (PC) matching, and prostate-rectum boundary (PRB) matching. In the PC matching, translational movements of the prostate center were corrected after bone matching. In the PRB matching, we performed PC matching and correction along the anterior-posterior direction to match the boundary between the prostate and the rectum's anterior region. In each strategy, we evaluated systematic errors (Σ) and random errors (σ) by measuring the daily movements of certain points on each anatomic structure. The average positional deviations in millimeter of each point were determined by the Van Herk formula of 2.5Σ + 0.7σ. Using these positional deviations, we created planning target volumes of the prostate and SVs and analyzed the daily variation in the water equivalent length (WEL) from the skin surface to the target along the lateral beam directions using the density converted from the daily CT number. Based on this analysis, we designed prostate cancer treatment planning and evaluated the dose volume histograms (DVHs) for these strategies. The SVs' daily movements showed large variations over the superior-inferior direction, as did the rectum's anterior region. The average positional deviations of the prostate in the anterior, posterior, superior, inferior, and lateral sides (mm) in bone matching, PC matching, and PRB matching were (8.9, 9.8, 7.5, 3.6, 1.6), (5.6, 6.1, 3.5, 4.5, 1.9), and (8.6, 3.2, 3.5, 4.5, 1.9) (mm), respectively. Moreover, the ones of the SV tip were similarly (22.5, 15.5, 11

  1. Combined FDG-PET/CT for the detection of unknown primary tumors: systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Kwee, Thomas C.; Kwee, Robert M.

    2009-01-01

    The aim of this study was to systematically review and meta-analyze published data on the diagnostic performance of combined 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the detection of primary tumors in patients with cancer of unknown primary (CUP). A systematic search for relevant studies was performed of the PubMed/MEDLINE and Embase databases. Methodological quality of the included studies was assessed. Reported detection rates, sensitivities and specificities were meta-analyzed. Subgroup analyses were performed if results of individual studies were heterogeneous. The 11 included studies, comprising a total sample size of 433 patients with CUP, had moderate methodological quality. Overall primary tumor detection rate, pooled sensitivity and specificity of FDG-PET/CT were 37%, 84% (95% CI 78-88%) and 84% (95% CI 78-89%), respectively. Sensitivity was heterogeneous across studies (P = 0.0001), whereas specificity was homogeneous across studies (P = 0.2114). Completeness of diagnostic workup before FDG-PET/CT, location of metastases of unknown primary, administration of CT contrast agents, type of FDG-PET/CT images evaluated and way of FDG-PET/CT review did not significantly influence diagnostic performance. In conclusion, FDG-PET/CT can be a useful method for unknown primary tumor detection. Future studies are required to prove the assumed advantage of FDG-PET/CT over FDG-PET alone and to further explore causes of heterogeneity. (orig.)

  2. Present and future in the use of micro-CT scanner 3D analysis for the study of dental and root canal morphology.

    Science.gov (United States)

    Grande, Nicola M; Plotino, Gianluca; Gambarini, Gianluca; Testarelli, Luca; D'Ambrosio, Ferdinando; Pecci, Raffaella; Bedini, Rossella

    2012-01-01

    The goal of the present article is to illustrate and analyze the applications and the potential of microcomputed tomography (micro-CT) in the analysis of tooth anatomy and root canal morphology. The authors performed a micro-CT analysis of the following different teeth: maxillary first molars with a second canal in the mesiobuccal (MB) root, mandibular first molars with complex anatomy in the mesial root, premolars with single and double roots and with complicated apical anatomy. The hardware device used in this study was a desktop X-ray microfocus CT scanner (SkyScan 1072, SkyScan bvba, Aartselaar, Belgium). A specific software ResolveRT Amira (Visage Imaging) was used for the 3D analysis and imaging. The authors obtained three-dimensional images from 15 teeth. It was possible to precisely visualize and analyze external and internal anatomy of teeth, showing the finest details. Among the 5 upper molars analyzed, in three cases, the MB canals joined into one canal, while in the other two molars the two mesial canals were separate. Among the lower molars two of the five samples exhibited a single canal in the mesial root, which had a broad, flat appearance in a mesiodistal dimension. In the five premolar teeth, the canals were independent; however, the apical delta and ramifications of the root canals were quite complex. Micro-CT offers a simple and reproducible technique for 3D noninvasive assessment of the anatomy of root canal systems.

  3. Present and future in the use of micro-CT scanner 3D analysis for the study of dental and root canal morphology

    Directory of Open Access Journals (Sweden)

    Nicola M. Grande

    2012-01-01

    Full Text Available The goal of the present article is to illustrate and analyze the applications and the potential of microcomputed tomography (micro-CT in the analysis of tooth anatomy and root canal morphology. The authors performed a micro-CT analysis of the following different teeth: maxillary first molars with a second canal in the mesiobuccal (MB root, mandibular first molars with complex anatomy in the mesial root, premolars with single and double roots and with complicated apical anatomy. The hardware device used in this study was a desktop X-ray microfocus CT scanner (SkyScan 1072, SkyScan bvba, Aartselaar, Belgium. A specific software ResolveRT Amira (Visage Imaging was used for the 3D analysis and imaging. The authors obtained three-dimensional images from 15 teeth. It was possible to precisely visualize and analyze external and internal anatomy of teeth, showing the finest details. Among the 5 upper molars analyzed, in three cases, the MB canals joined into one canal, while in the other two molars the two mesial canals were separate. Among the lower molars two of the five samples exhibited a single canal in the mesial root, which had a broad, flat appearance in a mesiodistal dimension. In the five premolar teeth, the canals were independent; however, the apical delta and ramifications of the root canals were quite complex. Micro-CT offers a simple and reproducible technique for 3D noninvasive assessment of the anatomy of root canal systems.

  4. Proton range shift analysis on brain pseudo-CT generated from T1 and T2 MR.

    Science.gov (United States)

    Pileggi, Giampaolo; Speier, Christoph; Sharp, Gregory C; Izquierdo Garcia, David; Catana, Ciprian; Pursley, Jennifer; Amato, Francesco; Seco, Joao; Spadea, Maria Francesca

    2018-05-29

    In radiotherapy, MR imaging is only used because it has significantly better soft tissue contrast than CT, but it lacks electron density information needed for dose calculation. This work assesses the feasibility of using pseudo-CT (pCT) generated from T1w/T2w MR for proton treatment planning, where proton range comparisons are performed between standard CT and pCT. MR and CT data from 14 glioblastoma patients were used in this study. The pCT was generated by using conversion libraries obtained from tissue segmentation and anatomical regioning of the T1w/T2w MR. For each patient, a plan consisting of three 18 Gy beams was designed on the pCT, for a total of 42 analyzed beams. The plan was then transferred onto the CT that represented the ground truth. Range shift (RS) between pCT and CT was computed at R 80 over 10 slices. The acceptance threshold for RS was according to clinical guidelines of two institutions. A γ-index test was also performed on the total dose for each patient. Mean absolute error and bias for the pCT were 124 ± 10 and -16 ± 26 Hounsfield Units (HU), respectively. The median and interquartile range of RS was 0.5 and 1.4 mm, with highest absolute value being 4.4 mm. Of the 42 beams, 40 showed RS less than the clinical range margin. The two beams with larger RS were both in the cranio-caudal direction and had segmentation errors due to the partial volume effect, leading to misassignment of the HU. This study showed the feasibility of using T1w and T2w MRI to generate a pCT for proton therapy treatment, thus avoiding the use of a planning CT and allowing better target definition and possibilities for online adaptive therapies. Further improvements of the methodology are still required to improve the conversion from MRI intensities to HUs.

  5. Semi-automatic analysis of standard uptake values in serial PET/CT studies in patients with lung cancer and lymphoma

    Directory of Open Access Journals (Sweden)

    Ly John

    2012-04-01

    Full Text Available Abstract Background Changes in maximum standardised uptake values (SUVmax between serial PET/CT studies are used to determine disease progression or regression in oncologic patients. To measure these changes manually can be time consuming in a clinical routine. A semi-automatic method for calculation of SUVmax in serial PET/CT studies was developed and compared to a conventional manual method. The semi-automatic method first aligns the serial PET/CT studies based on the CT images. Thereafter, the reader selects an abnormal lesion in one of the PET studies. After this manual step, the program automatically detects the corresponding lesion in the other PET study, segments the two lesions and calculates the SUVmax in both studies as well as the difference between the SUVmax values. The results of the semi-automatic analysis were compared to that of a manual SUVmax analysis using a Philips PET/CT workstation. Three readers did the SUVmax readings in both methods. Sixteen patients with lung cancer or lymphoma who had undergone two PET/CT studies were included. There were a total of 26 lesions. Results Linear regression analysis of changes in SUVmax show that intercepts and slopes are close to the line of identity for all readers (reader 1: intercept = 1.02, R2 = 0.96; reader 2: intercept = 0.97, R2 = 0.98; reader 3: intercept = 0.99, R2 = 0.98. Manual and semi-automatic method agreed in all cases whether SUVmax had increased or decreased between the serial studies. The average time to measure SUVmax changes in two serial PET/CT examinations was four to five times longer for the manual method compared to the semi-automatic method for all readers (reader 1: 53.7 vs. 10.5 s; reader 2: 27.3 vs. 6.9 s; reader 3: 47.5 vs. 9.5 s; p Conclusions Good agreement was shown in assessment of SUVmax changes between manual and semi-automatic method. The semi-automatic analysis was four to five times faster to perform than the manual analysis. These findings show the

  6. Effects of registration error on parametric response map analysis: a simulation study using liver CT-perfusion images

    International Nuclear Information System (INIS)

    Lausch, A; Lee, T Y; Wong, E; Jensen, N K G; Chen, J; Lock, M

    2014-01-01

    Purpose: To investigate the effects of registration error (RE) on parametric response map (PRM) analysis of pre and post-radiotherapy (RT) functional images. Methods: Arterial blood flow maps (ABF) were generated from the CT-perfusion scans of 5 patients with hepatocellular carcinoma. ABF values within each patient map were modified to produce seven new ABF maps simulating 7 distinct post-RT functional change scenarios. Ground truth PRMs were generated for each patient by comparing the simulated and original ABF maps. Each simulated ABF map was then deformed by different magnitudes of realistic respiratory motion in order to simulate RE. PRMs were generated for each of the deformed maps and then compared to the ground truth PRMs to produce estimates of RE-induced misclassification. Main findings: The percentage of voxels misclassified as decreasing, no change, and increasing, increased with RE For all patients, increasing RE was observed to increase the number of high post-RT ABF voxels associated with low pre-RT ABF voxels and vice versa. 3 mm of average tumour RE resulted in 18-45% tumour voxel misclassification rates. Conclusions: RE induced misclassification posed challenges for PRM analysis in the liver where registration accuracy tends to be lower. Quantitative understanding of the sensitivity of the PRM method to registration error is required if PRMs are to be used to guide radiation therapy dose painting techniques.

  7. Influence of Manufacturing Methods of Implant-Supported Crowns on External and Internal Marginal Fit: A Micro-CT Analysis.

    Science.gov (United States)

    Moris, Izabela C M; Monteiro, Silas Borges; Martins, Raíssa; Ribeiro, Ricardo Faria; Gomes, Erica A

    2018-01-01

    To evaluate the influence of different manufacturing methods of single implant-supported metallic crowns on the internal and external marginal fit through computed microtomography. Forty external hexagon implants were divided into 4 groups ( n = 8), according to the manufacturing method: GC, conventional casting; GI, induction casting; GP, plasma casting; and GCAD, CAD/CAM machining. The crowns were attached to the implants with insertion torque of 30 N·cm. The external (vertical and horizontal) marginal fit and internal fit were assessed through computed microtomography. Internal and external marginal fit data ( μ m) were submitted to a one-way ANOVA and Tukey's test ( α = .05). Qualitative evaluation of the images was conducted by using micro-CT. The statistical analysis revealed no significant difference between the groups for vertical misfit ( P = 0.721). There was no significant difference ( P > 0.05) for the internal and horizontal marginal misfit in the groups GC, GI, and GP, but it was found for the group GCAD ( P ≤ 0.05). Qualitative analysis revealed that most of the samples of cast groups exhibited crowns underextension while the group GCAD showed overextension. The manufacturing method of the crowns influenced the accuracy of marginal fit between the prosthesis and implant. The best results were found for the crowns fabricated through CAD/CAM machining.

  8. Influence of Manufacturing Methods of Implant-Supported Crowns on External and Internal Marginal Fit: A Micro-CT Analysis

    Directory of Open Access Journals (Sweden)

    Izabela C. M. Moris

    2018-01-01

    Full Text Available Aim. To evaluate the influence of different manufacturing methods of single implant-supported metallic crowns on the internal and external marginal fit through computed microtomography. Methods. Forty external hexagon implants were divided into 4 groups (n=8, according to the manufacturing method: GC, conventional casting; GI, induction casting; GP, plasma casting; and GCAD, CAD/CAM machining. The crowns were attached to the implants with insertion torque of 30 N·cm. The external (vertical and horizontal marginal fit and internal fit were assessed through computed microtomography. Internal and external marginal fit data (μm were submitted to a one-way ANOVA and Tukey’s test (α=.05. Qualitative evaluation of the images was conducted by using micro-CT. Results. The statistical analysis revealed no significant difference between the groups for vertical misfit (P=0.721. There was no significant difference (P>0.05 for the internal and horizontal marginal misfit in the groups GC, GI, and GP, but it was found for the group GCAD (P≤0.05. Qualitative analysis revealed that most of the samples of cast groups exhibited crowns underextension while the group GCAD showed overextension. Conclusions. The manufacturing method of the crowns influenced the accuracy of marginal fit between the prosthesis and implant. The best results were found for the crowns fabricated through CAD/CAM machining.

  9. Assessment of tumor heterogeneity by CT texture analysis: Can the largest cross-sectional area be used as an alternative to whole tumor analysis?

    International Nuclear Information System (INIS)

    Ng, Francesca; Kozarski, Robert; Ganeshan, Balaji; Goh, Vicky

    2013-01-01

    Objective: To determine if there is a difference between contrast enhanced CT texture features from the largest cross-sectional area versus the whole tumor, and its effect on clinical outcome prediction. Methods: Entropy (E) and uniformity (U) were derived for different filter values (1.0–2.5: fine to coarse textures) for the largest primary tumor cross-sectional area and the whole tumor of the staging contrast enhanced CT in 55 patients with primary colorectal cancer. Parameters were compared using non-parametric Wilcoxon test. Kaplan–Meier analysis was performed to determine the relationship between CT texture and 5-year overall survival. Results: E was higher and U lower for the whole tumor indicating greater heterogeneity at all filter levels (1.0–2.5): median (range) for E and U for whole tumor versus largest cross-sectional area of 7.89 (7.43–8.31) versus 7.62 (6.94–8.08) and 0.005 (0.004–0.01) versus 0.006 (0.005–0.01) for filter 1.0; 7.88 (7.22–8.48) versus 7.54 (6.86–8.1) and 0.005 (0.003–0.01) versus 0.007 (0.004–0.01) for filter 1.5; 7.88 (7.17–8.54) versus 7.48 (5.84–8.25) and 0.005 (0.003–0.01) versus 0.007 (0.004–0.02) for filter 2.0; and 7.83 (7.03–8.57) versus 7.42 (5.19–8.26) and 0.005 (0.003–0.01) versus 0.006 (0.004–0.03) for filter 2.5 respectively (p ≤ 0.001). Kaplan–Meier analysis demonstrated better separation of E and U for whole tumor analysis for 5-year overall survival. Conclusion: Whole tumor analysis appears more representative of tumor heterogeneity

  10. Bowtie filters for dedicated breast CT: Analysis of bowtie filter material selection

    Energy Technology Data Exchange (ETDEWEB)

    Kontson, Kimberly, E-mail: Kimberly.Kontson@fda.hhs.gov; Jennings, Robert J. [Department of Bioengineering, University of Maryland, College Park, Maryland 20742 and Division of Imaging and Applied Mathematics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993 (United States)

    2015-09-15

    , and scatter were investigated. Results: Analytical calculations with and without each bowtie filter show that some materials for a given design produce bowtie filters that are too large for implementation in breast CT scanners or too small to accurately manufacture. Results also demonstrate the ability to manipulate the energy fluence distribution (dynamic range) by using different materials, or different combinations of materials, for a given bowtie filter design. This feature is especially advantageous when using photon counting detector technology. Monte Carlo simulation results from PENELOPE show that all studied material choices for bowtie design #2 achieve nearly uniform dose distribution, noise uniformity index less than 5%, and nearly uniform scatter-to-primary ratio. These same features can also be obtained using certain materials with bowtie designs #1 and #3. Conclusions: With the three bowtie filter designs used in this work, the selection of material is an important design consideration. An appropriate material choice can improve image quality, dose uniformity, and dynamic range.

  11. Bowtie filters for dedicated breast CT: Analysis of bowtie filter material selection

    International Nuclear Information System (INIS)

    Kontson, Kimberly; Jennings, Robert J.

    2015-01-01

    , and scatter were investigated. Results: Analytical calculations with and without each bowtie filter show that some materials for a given design produce bowtie filters that are too large for implementation in breast CT scanners or too small to accurately manufacture. Results also demonstrate the ability to manipulate the energy fluence distribution (dynamic range) by using different materials, or different combinations of materials, for a given bowtie filter design. This feature is especially advantageous when using photon counting detector technology. Monte Carlo simulation results from PENELOPE show that all studied material choices for bowtie design #2 achieve nearly uniform dose distribution, noise uniformity index less than 5%, and nearly uniform scatter-to-primary ratio. These same features can also be obtained using certain materials with bowtie designs #1 and #3. Conclusions: With the three bowtie filter designs used in this work, the selection of material is an important design consideration. An appropriate material choice can improve image quality, dose uniformity, and dynamic range

  12. Automated measurement of heterogeneity in CT images of healthy and diseased rat lungs using variogram analysis of an octree decomposition

    International Nuclear Information System (INIS)

    Jacob, Richard E; Carson, James P

    2014-01-01

    Assessing heterogeneity in lung images can be an important diagnosis tool. We present a novel and objective method for assessing lung damage in a rat model of emphysema. We combined a three-dimensional (3D) computer graphics method–octree decomposition–with a geostatistics-based approach for assessing spatial relationships–the variogram–to evaluate disease in 3D computed tomography (CT) image volumes. Male, Sprague-Dawley rats were dosed intratracheally with saline (control), or with elastase dissolved in saline to either the whole lung (for mild, global disease) or a single lobe (for severe, local disease). Gated 3D micro-CT images were acquired on the lungs of all rats at end expiration. Images were masked, and octree decomposition was performed on the images to reduce the lungs to homogeneous blocks of 2 × 2 × 2, 4 × 4 × 4, and 8 × 8 × 8 voxels. To focus on lung parenchyma, small blocks were ignored because they primarily defined boundaries and vascular features, and the spatial variance between all pairs of the 8 × 8 × 8 blocks was calculated as the square of the difference of signal intensity. Variograms–graphs of distance vs. variance–were constructed, and results of a least-squares-fit were compared. The robustness of the approach was tested on images prepared with various filtering protocols. Statistical assessment of the similarity of the three control rats was made with a Kruskal-Wallis rank sum test. A Mann-Whitney-Wilcoxon rank sum test was used to measure statistical distinction between individuals. For comparison with the variogram results, the coefficient of variation and the emphysema index were also calculated for all rats. Variogram analysis showed that the control rats were statistically indistinct (p = 0.12), but there were significant differences between control, mild global disease, and severe local disease groups (p < 0.0001). A heterogeneity index was calculated to describe the difference of an individual variogram from

  13. Comparison of CT numbers between cone-beam CT and multi-detector CT

    International Nuclear Information System (INIS)

    Kim, Dong Soo; Han, Won Jeong; Kim, Eun Kyung

    2010-01-01

    To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, ρ(g/cm 3 ), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were ρ=0.001 H+1.07 with R2 value of 0.999 for Somatom Emotion, ρ=0.002 H+1.09 with R2 value of 0.991 for Alphard VEGA, ρ=0.001 H+1.43 with R2 value of 0.980 for i-CAT and ρ=0.001 H+1.30 with R2 value of 0.975 for Implagraphy. CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

  14. Comparison of CT numbers between cone-beam CT and multi-detector CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Soo; Han, Won Jeong; Kim, Eun Kyung [Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University, Cheonan (Korea, Republic of)

    2010-06-15

    To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, {rho}(g/cm{sup 3}), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were {rho}=0.001 H+1.07 with R2 value of 0.999 for Somatom Emotion, {rho}=0.002 H+1.09 with R2 value of 0.991 for Alphard VEGA, {rho}=0.001 H+1.43 with R2 value of 0.980 for i-CAT and {rho}=0.001 H+1.30 with R2 value of 0.975 for Implagraphy. CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

  15. Establishment study of the in vivo imaging analysis with small animal imaging modalities (micro-PET and micro-SPECT/CT) for bio-drug development

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Beomsu; Park, Sanghyeon; Park, Jeonghoon; Jo, Sungkee; Jung, Uhee; Kim, Seolwha; Lee, Yunjong; Choi, Daeseong

    2011-01-15

    In this study, we established the image acquisition and analysis procedures of micro-PET, SPECT/CT using the experimental animal (mouse) for the development of imaging assessment method for the bio-drug. We examined the micro-SPECT/CT, PET imaging study using the Siemens Inveon micro-multimodality system (SPECT/CT) and micro-PET with {sup 99m}Tc-MDP, DMSA, and {sup 18}F-FDG. SPECT imaging studies using 3 types of pinhole collimators. 5-MWB collimator was used for SPECT image study. To study whole-body distribution, {sup 99m}Tc-MDP SPECT image study was performed. We obtained the fine distribution image. And the CT images was obtained to provide the anatomical information. And then these two types images are fused. To study specific organ uptake, we examined {sup 99}mTc-DMSA SPECT/CT imaging study. We also performed the PET image study using U87MG tumor bearing mice and {sup 18}F-FDG. The overnight fasting, warming and anesthesia with 2% isoflurane pretreatment enhance the tumor image through reducing the background uptake including brown fat, harderian gland and skeletal muscles. Also we got the governmental approval for use of x-ray generator for CT and radioisotopes as sealed and open source. We prepared the draft of process procedure for the experimental animal imaging facility. These research results can be utilized as a basic image study protocols and data for the image assessment of drugs including biological drug.

  16. Calibration and analysis of a multimodal micro-CT and structured light imaging system for the evaluation of excised breast tissue

    Science.gov (United States)

    McClatchy, David M., III; Rizzo, Elizabeth J.; Meganck, Jeff; Kempner, Josh; Vicory, Jared; Wells, Wendy A.; Paulsen, Keith D.; Pogue, Brian W.

    2017-12-01

    A multimodal micro-computed tomography (CT) and multi-spectral structured light imaging (SLI) system is introduced and systematically analyzed to test its feasibility to aid in margin delineation during breast conserving surgery (BCS). Phantom analysis of the micro-CT yielded a signal-to-noise ratio of 34, a contrast of 1.64, and a minimum detectable resolution of 240 μm for a 1.2 min scan. The SLI system, spanning wavelengths 490 nm to 800 nm and spatial frequencies up to 1.37 mm-1 , was evaluated with aqueous tissue simulating phantoms having variations in particle size distribution, scatter density, and blood volume fraction. The reduced scattering coefficient, μs\\prime and phase function parameter, γ, were accurately recovered over all wavelengths independent of blood volume fractions from 0% to 4%, assuming a flat sample geometry perpendicular to the imaging plane. The resolution of the optical system was tested with a step phantom, from which the modulation transfer function was calculated yielding a maximum resolution of 3.78 cycles per mm. The three dimensional spatial co-registration between the CT and optical imaging space was tested and shown to be accurate within 0.7 mm. A freshly resected breast specimen, with lobular carcinoma, fibrocystic disease, and adipose, was imaged with the system. The micro-CT provided visualization of the tumor mass and its spiculations, and SLI yielded superficial quantification of light scattering parameters for the malignant and benign tissue types. These results appear to be the first demonstration of SLI combined with standard medical tomography for imaging excised tumor specimens. While further investigations are needed to determine and test the spectral, spatial, and CT features required to classify tissue, this study demonstrates the ability of multimodal CT/SLI to quantify, visualize, and spatially navigate breast tumor specimens, which could potentially aid in the assessment of tumor margin status during

  17. Effect of tensile properties on time-dependent C(t) and J(t) integrals in elastic-plastic-creep FE analysis

    International Nuclear Information System (INIS)

    Lee, So-Dam; Lee, Han-Sang; Kim, Yun-Jae; Ainsworth, Robert A.; Dean, David W.

    2016-01-01

    This technical note presents the effect of elastic-plastic properties on calculated time-dependent C(t) and J(t) values. This is investigated via systematic elastic-plastic-creep finite element (FE) analysis. Three different stress-strain curves are used, having essentially the same plastic properties at large strains but different tensile data near the 0.2% proof (yield) strength. It is found that the plastic property in stress-strain curve affects the FE C(t) values only at short times (within approximately 20% of the redistribution time). The plastic property affects the initial J values at time t = 0 but not the rate of change of J(t) with time. - Highlights: • The effect of elastic-plastic properties on calculated time-dependent C(t) and J(t) values is presented via FE analysis. • The plastic property affects the FE C(t) values only at short times up to ∼20% of the redistribution time. • The plastic property affects the initial J values at time t = 0 but not the rate of change of J(t) with time.

  18. Dual-energy CT in vertebral compression fractures: performance of visual and quantitative analysis for bone marrow edema demonstration with comparison to MRI.

    Science.gov (United States)

    Bierry, Guillaume; Venkatasamy, Aïna; Kremer, Stéphane; Dosch, Jean-Claude; Dietemann, Jean-Louis

    2014-04-01

    To prospectively evaluate the performance of virtual non-calcium (VNC) dual-energy CT (DECT) images for the demonstration of trauma-related abnormal marrow attenuation in collapsed and non-collapsed vertebral compression fractures (VCF) with MRI as a reference standard. Twenty patients presenting with non-tumoral VCF were consecutively and prospectively included in this IRB-approved study, and underwent MRI and DECT of the spine. MR examination served as a reference standard. Two independent readers visually evaluated all vertebrae for abnormal marrow attenuation ("CT edema") on VNC DECT images; specificity, sensitivity, predictive values, intra and inter-observer agreements were calculated. A last reader performed a quantitative evaluation of CT numbers; cut-off values were calculated using ROC analysis. In the visual analysis, VNC DECT images had an overall sensitivity of 84%, specificity of 97%, and accuracy of 95%, intra- and inter-observer agreements ranged from k = 0.74 to k = 0.90. CT numbers were significantly different between vertebrae with edema on MR and those without (p VNC DECT images allowed an accurate demonstration of trauma-related abnormal attenuation in VCF, revealing the acute nature of the fracture, on both visual and quantitative evaluation.

  19. CT in neuromuscular disorders: A comparison of CT and histology

    International Nuclear Information System (INIS)

    Vliet, A.M. van der; Thijssen, H.O.M.; Merx, J.L.; Joosten, E.

    1988-01-01

    The value of CT-examination of the muscles compared to histology was studied in a retrospective analysis of 30 patients with clinical suspicion of neuromuscular disorder. In the evaluation of the CT-results descriptive criteria were used. The histologic diagnosis came from needle-biopsies taken from the quadriceps muscle. Considering the whole group of neuromuscular disorders, CT has an overall accuracy of 84.8%, a positive predictive value of 95.5% and a negative predictive value of 63.6%. This makes the use of CT as a diagnostic tool in neuromuscular disorders a reliable examination technique. In patients with a polymyositis there is even a 100% correlation between CT findings and biopsy results. Discrepancy between the biopsy results is remarkable of the quadriceps muscle and the CT findings: The number of abnormal histological findings is twice the number of abnormal CT findings. Using the more proximal gluteal region as a biopsy site would have decreased this discrepancy and would therefore have given a better correlation between CT and histology. The choice of protocol in determining the levels to be scanned is of great importance in achieving good reproducability in follow-up CT examinations. (orig.)

  20. Vertebral artery and osseous anomalies characteristic at the craniocervical junction diagnosed by CT and 3D CT angiography in normal Czech population: analysis of 511 consecutive patients.

    Science.gov (United States)

    Vaněk, P; Bradáč, Ondřej; de Lacy, P; Konopková, R; Lacman, J; Beneš, V

    2017-07-01

    There are numerous indications for stabilization using instrumentation of the upper cervical spine. This area is comprised of sophisticated anatomy. There is no study describing bony and vascular anomalies of this area in the middle European population. The main aim of this study was to investigate prevalence of any vertebral artery (VA) variations and osseous anomalies in the region of the craniocervical junction in a large sample of Czech patients based on three-dimensional computed tomographic angiography (3D CTA). The VA has a variable course through C2 before it passes above its groove on the posterior arch of C1. The artery can course more medially, more posteriorly or more superiorly, thus limiting the diameter of the bony elements used as landmarks for the safe insertion of metalwork. This is known as a high-riding VA (HRVA). The VA was considered HRVA in this study if the thickness of the C2 isthmus was less than 5 mm and/or the C2 internal height was less than 2 mm and/or the width of the C2 pedicle was less than 4 mm. The prevalence of ponticulus posticus (PP) was also identified. Following the VA variations in the V3 segment of the artery were persistent first intersegmental artery (FIA), fenestration (FEN) of the VA, and the posterior inferior cerebellar artery (PICA) branch originating from the C1/2 part of VA. Records of 511 patients from our institution were analyzed. The mean age of the patients was 63.6 years. One hundred and twenty-three (24.1 %) patients were identified to have HRVA, 30 (6 %) present on both sides. The age of patient over 70 years and female sex were found to be significant risk factors for HRVA presence. The prevalence of a nearby PICA branch was 4 %, FIA was 0.4 %, and FEN was 0.2 %. The presence of PP was identified in 14.3 % of patients. The HRVA and PP are common anomalies in the Czech population, and routine preoperative high-resolution CT evaluation is mandatory to prevent the VA injury when C1-C2

  1. Should PET/CT be implemented in the routine imaging work-up of locally advanced head and neck squamous cell carcinoma? A prospective analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cacicedo, Jon; Bilbao, Pedro [Cruces University Hospital, Radiation Oncology Department, Barakaldo, Bizkaia (Basque Country) (Spain); BioCruces Health Research Institute, Bizkaia, Basque Country (Spain); Fernandez, Iratxe [Cruces University Hospital, Nuclear Medicine Department, Barakaldo (Spain); Hoyo, Olga del; Hortelano, Eduardo [Cruces University Hospital, Radiation Oncology Department, Barakaldo, Bizkaia (Basque Country) (Spain); Dolado, Ainara [Cruces University Hospital, Radiodiagnostic and Medical Imaging Department, Barakaldo (Spain); Gomez-Suarez, Javier [Cruces University Hospital, Otolaryngology Department, Barakaldo (Spain); Sancho, Aintzane [Cruces University Hospital, Medical Oncology Department, Barakaldo (Spain); Pijoan, Jose I. [BioCruces Health Research Institute, Bizkaia, Basque Country (Spain); Cruces University Hospital, Clinical Epidemiology Unit, Barakaldo (Spain); CIBER de Epidemiologia y Salud Publica (CIBERESP), Madrid (Spain); Alvarez, Julio [Cruces University Hospital, Oral and Maxillofacial Surgery Department, Barakaldo (Spain); Espinosa, Jose M. [Cruces University Hospital, Medical Physics Department, Barakaldo (Spain); Gaafar, Ayman [Cruces University Hospital, Department of Pathology, Barakaldo (Spain)

    2015-08-15

    The objective of this study was to determine the incremental staging information provided by positron emission tomography/computed tomography (PET/CT) and its impact on management plans in patients with untreated stage III-IV head and neck squamous cell carcinoma (HNSCC). We prospectively studied, between September 2011 and February 2013, 84 consecutive patients [median age 63.5 years (39-84); 73 men] with histologically confirmed HNSCC. First, based on a conventional work-up (physical examination, CT imaging of the head, neck and chest), the multidisciplinary Head and Neck Tumour Board documented the TNM stage and a management plan for each patient, outlining the modalities to be used, including surgery, radiation therapy (RT), chemotherapy or a combination. After release of the PET/CT results, new TNM staging and management plans were agreed on by the multidisciplinary Tumour Board. Any changes in stage or intended management due to the PET/CT findings were then analysed. The impact on patient management was classified as: low (treatment modality, delivery and intent unchanged), moderate (change within the same treatment modality: type of surgery, radiation technique/dose) or high (change in treatment intent and/or treatment modality → curative to palliative, or surgery to chemoradiation or detection of unknown primary tumour or a synchronous second primary tumour). TNM stage was validated by histopathological analysis, additional imaging or follow-up. Accuracy of the conventional and PET/CT-based staging was compared using McNemar's test. Conventional and PET/CT stages were discordant in 32/84 (38 %) cases: the T stage in 2/32 (6.2 %), the N stage in 21/32 (65.7 %) and the M stage 9/32 (28.1 %). Patient management was altered in 22/84 (26 %) patients, with a moderate impact in 8 (9.5 %) patients and high impact in 14 (16.6 %) patients. PET/CT TNM classification was significantly more accurate (92.5 vs 73.7 %) than conventional staging with a p value < 0

  2. Should PET/CT be implemented in the routine imaging work-up of locally advanced head and neck squamous cell carcinoma? A prospective analysis

    International Nuclear Information System (INIS)

    Cacicedo, Jon; Bilbao, Pedro; Fernandez, Iratxe; Hoyo, Olga del; Hortelano, Eduardo; Dolado, Ainara; Gomez-Suarez, Javier; Sancho, Aintzane; Pijoan, Jose I.; Alvarez, Julio; Espinosa, Jose M.; Gaafar, Ayman

    2015-01-01

    The objective of this study was to determine the incremental staging information provided by positron emission tomography/computed tomography (PET/CT) and its impact on management plans in patients with untreated stage III-IV head and neck squamous cell carcinoma (HNSCC). We prospectively studied, between September 2011 and February 2013, 84 consecutive patients [median age 63.5 years (39-84); 73 men] with histologically confirmed HNSCC. First, based on a conventional work-up (physical examination, CT imaging of the head, neck and chest), the multidisciplinary Head and Neck Tumour Board documented the TNM stage and a management plan for each patient, outlining the modalities to be used, including surgery, radiation therapy (RT), chemotherapy or a combination. After release of the PET/CT results, new TNM staging and management plans were agreed on by the multidisciplinary Tumour Board. Any changes in stage or intended management due to the PET/CT findings were then analysed. The impact on patient management was classified as: low (treatment modality, delivery and intent unchanged), moderate (change within the same treatment modality: type of surgery, radiation technique/dose) or high (change in treatment intent and/or treatment modality → curative to palliative, or surgery to chemoradiation or detection of unknown primary tumour or a synchronous second primary tumour). TNM stage was validated by histopathological analysis, additional imaging or follow-up. Accuracy of the conventional and PET/CT-based staging was compared using McNemar's test. Conventional and PET/CT stages were discordant in 32/84 (38 %) cases: the T stage in 2/32 (6.2 %), the N stage in 21/32 (65.7 %) and the M stage 9/32 (28.1 %). Patient management was altered in 22/84 (26 %) patients, with a moderate impact in 8 (9.5 %) patients and high impact in 14 (16.6 %) patients. PET/CT TNM classification was significantly more accurate (92.5 vs 73.7 %) than conventional staging with a p value < 0

  3. Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis

    International Nuclear Information System (INIS)

    Lin, Yuning; Chen, Ziqian; Yang, Xizhang; Zhong, Qun; Zhang, Hongwen; Yang, Li; Xu, Shangwen; Li, Hui

    2013-01-01

    The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation. Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined. Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P=0.25) nor DSA (P=1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P=1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA. Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis.

  4. Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis.

    Science.gov (United States)

    Lin, Yuning; Chen, Ziqian; Yang, Xizhang; Zhong, Qun; Zhang, Hongwen; Yang, Li; Xu, Shangwen; Li, Hui

    2013-12-01

    The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation. Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined. Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P = 0.25) nor DSA (P = 1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P = 1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA. Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  5. Quantitative analysis of arterial flow properties for detection of non-calcified plaques in ECG-gated coronary CT angiography

    Science.gov (United States)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella

    2015-03-01

    We are developing a computer-aided detection system to assist radiologists in detection of non-calcified plaques (NCPs) in coronary CT angiograms (cCTA). In this study, we performed quantitative analysis of arterial flow properties in each vessel branch and extracted flow information to differentiate the presence and absence of stenosis in a vessel segment. Under rest conditions, blood flow in a single vessel branch was assumed to follow Poiseuille's law. For a uniform pressure distribution, two quantitative flow features, the normalized arterial compliance per unit length (Cu) and the normalized volumetric flow (Q) along the vessel centerline, were calculated based on the parabolic Poiseuille solution. The flow features were evaluated for a two-class classification task to differentiate NCP candidates obtained by prescreening as true NCPs and false positives (FPs) in cCTA. For evaluation, a data set of 83 cCTA scans was retrospectively collected from 83 patient files with IRB approval. A total of 118 NCPs were identified by experienced cardiothoracic radiologists. The correlation between the two flow features was 0.32. The discriminatory ability of the flow features evaluated as the area under the ROC curve (AUC) was 0.65 for Cu and 0.63 for Q in comparison with AUCs of 0.56-0.69 from our previous luminal features. With stepwise LDA feature selection, volumetric flow (Q) was selected in addition to three other luminal features. With FROC analysis, the test results indicated a reduction of the FP rates to 3.14, 1.98, and 1.32 FPs/scan at sensitivities of 90%, 80%, and 70%, respectively. The study indicated that quantitative blood flow analysis has the potential to provide useful features for the detection of NCPs in cCTA.

  6. Quantitative analysis of exercise 201Tl myocardial emission CT in patients with coronary artery disease

    International Nuclear Information System (INIS)

    Okada, Mitsuhiro; Kawai, Naoki; Yamamoto, Shuhei

    1984-01-01

    The clinical usefulness of quantitative analysis of exercise thallium-201 myocardial emission computed tomography (ECT) was evaluated in coronary artery disease (CAD). The subjects consisted of 20 CAD patients and five normal controls. All CAD patients underwent coronary angiography. Tomographic thallium-201 myocardial imaging was performed with a rotating gamma camera, and long-axial and short-axial myocardial images of the left ventricle were reconstructed. The tomographic images were interpreted quantitatively using circumferential profile analysis. Based on features of regional myocardial thallium-201 kinetics, two types of abnormalities were studied: (1) diminished initial distribution (stress defect) and (2) slow washout of thallium-201, as evidenced by patients' initial thallium-201 uptake and 3-hour washout rate profiles which fell below the normal limits, respectively. Two diagnostic criteria including the stress defect and a combination of the stress defect and slow washout were used to detect coronary artery lesions of significance (>=75 % luminal narrowing). The ischemic volumes were also evaluated by quantitative analysis using thallium-201 ECT. The diagnostic accuracy of the stress defect criterion was 95 % for left anterior descending, 90 % for right, and 70 % for left circumflex coronary artery lesions. The combined criteria of the stress defect and slow washout increased detection sensitivity with a moderate loss of specificity for identifying individual coronary artery lesion. A relatively high diagnostic accuracy was obtained using the stress defect criterion for multiple vessel disease (75 %). Ischemic myocardial volume was significantly larger in triple vessel than in single vessel disease (p < 0.05) using the combined criteria. It was concluded that quantitative analysis of exercise thallium-201 myocardial ECT images proves useful for evaluating coronary artery lesions. (author)

  7. Lung nodule detection performance in five observers on computed tomography (CT) with adaptive iterative dose reduction using three-dimensional processing (AIDR 3D) in a Japanese multicenter study: Comparison between ultra-low-dose CT and low-dose CT by receiver-operating characteristic analysis.

    Science.gov (United States)

    Nagatani, Yukihiro; Takahashi, Masashi; Murata, Kiyoshi; Ikeda, Mitsuru; Yamashiro, Tsuneo; Miyara, Tetsuhiro; Koyama, Hisanobu; Koyama, Mitsuhiro; Sato, Yukihisa; Moriya, Hiroshi; Noma, Satoshi; Tomiyama, Noriyuki; Ohno, Yoshiharu; Murayama, Sadayuki

    2015-07-01

    To compare lung nodule detection performance (LNDP) in computed tomography (CT) with adaptive iterative dose reduction using three dimensional processing (AIDR3D) between ultra-low dose CT (ULDCT) and low dose CT (LDCT). This was part of the Area-detector Computed Tomography for the Investigation of Thoracic Diseases (ACTIve) Study, a multicenter research project being conducted in Japan. Institutional Review Board approved this study and informed consent was obtained. Eighty-three subjects (body mass index, 23.3 ± 3.2) underwent chest CT at 6 institutions using identical scanners and protocols. In a single visit, each subject was scanned using different tube currents: 240, 120 and 20 mA (3.52, 1.74 and 0.29 mSv, respectively). Axial CT images with 2-mm thickness/increment were reconstructed using AIDR3D. Standard of reference (SOR) was determined based on CT images at 240 mA by consensus reading of 2 board-certificated radiologists as to the presence of lung nodules with the longest diameter (LD) of more than 3mm. Another 5 radiologists independently assessed and recorded presence/absence of lung nodules and their locations by continuously-distributed rating in CT images at 20 mA (ULDCT) and 120 mA (LDCT). Receiver-operating characteristic (ROC) analysis was used to evaluate LNDP of both methods in total and also in subgroups classified by LD (>4, 6 and 8 mm) and nodular characteristics (solid and ground glass nodules). For SOR, 161 solid and 60 ground glass nodules were identified. No significant difference in LNDP for entire solid nodules was demonstrated between both methods, as area under ROC curve (AUC) was 0.844 ± 0.017 in ULDCT and 0.876 ± 0.026 in LDCT (p=0.057). For ground glass nodules with LD 8mm or more, LNDP was similar between both methods, as AUC 0.899 ± 0.038 in ULDCT and 0.941 ± 0.030 in LDCT. (p=0.144). ULDCT using AIDR3D with an equivalent radiation dose to chest x-ray could have comparable LNDP to LDCT with AIDR3D except for smaller ground

  8. Photo-degradation of CT-DNA with a series of carbothioamide ruthenium (II) complexes - Synthesis and structural analysis

    Science.gov (United States)

    Muthuraj, V.; Umadevi, M.

    2018-04-01

    The present research article is related with the method of preparation, structure and spectroscopic properties of a series of carbothioamide ruthenium (II) complexes with N and S donor ligands namely, 2-((6-chloro-4-oxo-4H-chromen-3-yl)methylene) hydrazine carbothioamide (ClChrTs)/2-((6-methoxy-4-oxo-4H-chromen-3-yl)methylene)hydrazine carbothioamide (MeOChrTS). The synthesized complexes were characterized by several techniques using analytical methods as well as by spectral techniques such as FT-IR, 1HNMR, 13CNMR, ESI mass and thermogravimetry/differential thermal analysis (TG-DTA). The IR spectra shows that the ligand acts as a neutral bidentate with N and S donor atoms. The biological activity of the prepared compounds and metal complexes were tested against cell line of calf-thymus DNA via an intercalation mechanism (MCF-7). In addition, the interaction of Ru(II) complexes and its free ligands with CT-DNA were also investigated by titration with UV-Vis spectra, fluorescence spectra, and Circular dichroism studies. Results suggest that both of the two Ru(II) complexes can bind with calf-thymus DNA via an intercalation mechanism.

  9. Anatomical variations of hepatic arterial system, coeliac trunk and renal arteries: an analysis with multidetector CT angiography.

    Science.gov (United States)

    Ugurel, M S; Battal, B; Bozlar, U; Nural, M S; Tasar, M; Ors, F; Saglam, M; Karademir, I

    2010-08-01

    The purpose of our investigation was to determine the anatomical variations in the coeliac trunk-hepatic arterial system and the renal arteries in patients who underwent multidetector CT (MDCT) angiography of the abdominal aorta for various reasons. A total of 100 patients were analysed retrospectively. The coeliac trunk, hepatic arterial system and renal arteries were analysed individually and anatomical variations were recorded. Statistical analysis of the relationship between hepatocoeliac variations and renal artery variations was performed using a chi(2) test. There was a coeliac trunk trifurcation in 89% and bifurcation in 8% of the cases. Coeliac trunk was absent in 1%, a hepatosplenomesenteric trunk was seen in 1% and a splenomesenteric trunk was present in 1%. Hepatic artery variation was present in 48% of patients. Coeliac trunk and/or hepatic arterial variation was present in 23 (39.7%) of the 58 patients with normal renal arteries, and in 27 (64.3%) of the 42 patients with accessory renal arteries. There was a statistically significant correlation between renal artery variations and coeliac trunk-hepatic arterial system variations (p = 0.015). MDCT angiography permits a correct and detailed evaluation of hepatic and renal vascular anatomy. The prevalence of variations in the coeliac trunk and/or hepatic arteries is increased in people with accessory renal arteries. For that reason, when undertaking angiographic examinations directed towards any single organ, the possibility of variations in the vascular structure of other organs should be kept in mind.

  10. Development of a high-energy x-ray CT and its application to iron and steel analysis

    International Nuclear Information System (INIS)

    Taguchi, Isamu

    1987-01-01

    X-ray computed tomographic scanners are extensively used in medicine but have rarely been applied to non-medical purposes. Steel specimens pose particularly difficult problems - very poor transmission of X-rays and the need for high resolving capability. There have thus been no effective tomographic methods for examining steel specimens. Due to the growing need for non-destructive, non-contact methods for observing and analyzing the internal conditions of steel and raw materials for steel, however, we have developed a new high-energy computed tomographic scanner for steel (CTS). Its major specifications and functions are as follows. Type : 2nd-generation CT, 8-channel, Scanning method : 6deg revolution, 30-time traversing, Slice width : 0.3 mm, Resolving capability : 0.1 x 0.1 mm X-ray source : 420 kV, 3 mA, X-ray detector : BGO scintillator, Standard sample size : 50 mm dia., 50 mm high, Data collection time : 9.5 or 5 min. The CTS was successfully applied to the observation and the