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Sample records for ct colonography trial

  1. CT- and MR colonography

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  2. CT- and MR colonography

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  3. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... Image/Video Gallery Your Radiologist Explains CT Colonography (Virtual colonoscopy) Transcript Welcome to Radiology Info dot org! ... colonography or, as it is more commonly known, virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test ...

  4. CT colonography. A guide for clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Mang, Thomas [Medical Univ. of Vienna (Austria). Dept. of Radiology; Schima, Wolfgang [Krankenhaus Goettlicher Heiland, Wien (Austria). Dept. of Diagnostic and Interventional Radiology; Krankenhaus der Barmherzigen Schwestern, Wien (Austria); Sankt-Josef-Krankenhaus, Wien (Austria)

    2013-07-01

    The book on CT colonography - a guide for clinical practice - covers the following issues: indications and contraindications, examination; Image interpretation; findings at CT colonography, how to generate a useful report, screening, how to train for CT colonography.

  5. CT colonography: an update

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

  6. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... you today about computed tomography colonography or, as it is more commonly known, virtual colonoscopy. Virtual colonoscopy ... might have some concerns about CT scanning. However, it’s important to consider the likelihood of benefit from ...

  7. Your Radiologist Explains CT Colonography

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    Full Text Available ... you today about computed tomography colonography or, as it is more commonly known, virtual colonoscopy. Virtual colonoscopy ... might have some concerns about CT scanning. However, it’s important to consider the likelihood of benefit from ...

  8. Patient willingness for repeat screening and preference for CT colonography and optical colonoscopy in ACRIN 6664: the National CT Colonography trial

    Directory of Open Access Journals (Sweden)

    Gareen IF

    2015-07-01

    Full Text Available Ilana F Gareen,1,2 Bettina Siewert,3 David J Vanness,4 Benjamin Herman,2 CD Johnson,5 Constantine Gatsonis2,6 1Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA; 2Center for Statistical Sciences, Brown University School of Public Health, Providence, RI, USA; 3Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, USA; 4Population Health Sciences, University of Wisconsin, Madison, WI, USA; 5Mayo Clinic, Scottsdale, AZ, USA; 6Department of Biostatistics, Brown University School of Public Health, Providence, RI, USA Background: Current American Cancer Society recommendations for colon cancer screening include optical colonoscopy every 10 years or computed tomography colonography (CTC every 5 years. Bowel preparation (BP is currently required for both screening modalities.Purpose: To compare ACRIN 6664: the National CT Colonography Trial (NCTCT participant experiences with CTC and optical colonoscopy (OC, procedure preference, and willingness to return for each procedure.Materials and methods: Participants from fifteen NCTCT sites, who underwent CTC followed by OC under sedation, were invited to complete questionnaires 2 weeks postexam, asking about procedure preference, physical discomfort, and embarrassment experienced and whether that discomfort and embarrassment was better or worse than expected during BP, CTC, and OC, as well as willingness to return for repeat CTC and OC at different time intervals.Results: A total of 2,310 of 2,600 patients (89% returned their questionnaires. Of patients reporting a preference, 1,058 (46.6% preferred CTC, 569 (25.0% preferred OC, and 626 (27.6% reported no preference. Participant-reported discomfort worse than expected differed significantly between CTC (32.9% and OC (5.0% (P<0.001. About 79.3% were willing to be screened again with CTC in 5 years, and 96.6% with OC in 10 years. Discomfort and embarrassment worse than expected with OC were associated

  9. Patient willingness for repeat screening and preference for CT colonography and optical colonoscopy in ACRIN 6664: the National CT Colonography trial.

    Science.gov (United States)

    Gareen, Ilana F; Siewert, Bettina; Vanness, David J; Herman, Benjamin; Johnson, C D; Gatsonis, Constantine

    2015-01-01

    Current American Cancer Society recommendations for colon cancer screening include optical colonoscopy every 10 years or computed tomography colonography (CTC) every 5 years. Bowel preparation (BP) is currently required for both screening modalities. To compare ACRIN 6664: the National CT Colonography Trial (NCTCT) participant experiences with CTC and optical colonoscopy (OC), procedure preference, and willingness to return for each procedure. Participants from fifteen NCTCT sites, who underwent CTC followed by OC under sedation, were invited to complete questionnaires 2 weeks postexam, asking about procedure preference, physical discomfort, and embarrassment experienced and whether that discomfort and embarrassment was better or worse than expected during BP, CTC, and OC, as well as willingness to return for repeat CTC and OC at different time intervals. A total of 2,310 of 2,600 patients (89%) returned their questionnaires. Of patients reporting a preference, 1,058 (46.6%) preferred CTC, 569 (25.0%) preferred OC, and 626 (27.6%) reported no preference. Participant-reported discomfort worse than expected differed significantly between CTC (32.9%) and OC (5.0%) (Pembarrassment worse than expected with OC were associated with increased intention to adhere with CTC in the future. Conversely, embarrassment experienced during CTC and discomfort worse than expected on CTC were associated with increased intention to adhere with OC in the future. While a larger proportion of participants indicated that they preferred CTC to OC, willingness to undergo repeat CTC compared to OC was limited by unanticipated exam discomfort and embarrassment and CTC's shorter screening interval.

  10. Errors in CT colonography.

    Science.gov (United States)

    Trilisky, Igor; Ward, Emily; Dachman, Abraham H

    2015-10-01

    CT colonography (CTC) is a colorectal cancer screening modality which is becoming more widely implemented and has shown polyp detection rates comparable to those of optical colonoscopy. CTC has the potential to improve population screening rates due to its minimal invasiveness, no sedation requirement, potential for reduced cathartic examination, faster patient throughput, and cost-effectiveness. Proper implementation of a CTC screening program requires careful attention to numerous factors, including patient preparation prior to the examination, the technical aspects of image acquisition, and post-processing of the acquired data. A CTC workstation with dedicated software is required with integrated CTC-specific display features. Many workstations include computer-aided detection software which is designed to decrease errors of detection by detecting and displaying polyp-candidates to the reader for evaluation. There are several pitfalls which may result in false-negative and false-positive reader interpretation. We present an overview of the potential errors in CTC and a systematic approach to avoid them.

  11. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... Therapy November 8 is the International Day of Radiology (IDoR) Radiology and You Sponsored by Image/Video Gallery Your ... Explains CT Colonography (Virtual colonoscopy) Transcript Welcome to Radiology Info dot org! Hi, I’m Dr. Elliot ...

  12. Comparing CT colonography and flexible sigmoidoscopy: a randomised trial within a population-based screening programme.

    Science.gov (United States)

    Regge, Daniele; Iussich, Gabriella; Segnan, Nereo; Correale, Loredana; Hassan, Cesare; Arrigoni, Arrigo; Asnaghi, Roberto; Bestagini, Piero; Bulighin, Gianmarco; Cassinis, Maria Carla; Ederle, Andrea; Ferraris, Andrea; Galatola, Giovanni; Gallo, Teresa; Gandini, Giovanni; Garretti, Licia; Martina, Maria Cristina; Molinar, Daniela; Montemezzi, Stefania; Morra, Lia; Motton, Massimiliano; Occhipinti, Pietro; Pinali, Lucia; Soardi, Gian Alberto; Senore, Carlo

    2017-08-01

    The role of CT colonography (CTC) as a colorectal cancer (CRC) screening test is uncertain. The aim of our trial was to compare participation and detection rate (DR) with sigmoidoscopy (flexible sigmoidoscopy (FS)) and CTC in a screening setting. We conducted two randomised clinical trials (RCTs). (1) Participation RCT: individuals, aged 58 years, living in Turin (Italy), were randomly assigned to be invited to FS or CTC screening; (2) detection RCT: residents in northern Italy, aged 58-60, giving their consent to recruitment, were randomly allocated to CTC or FS. Polyps ≥6 mm at CTC, or 'high-risk' distal lesions at FS, were referred for colonoscopy (TC). Participation rate (proportion of invitees examined); DR of advanced adenomas or CRC (advanced neoplasia (AN)). Participation was 30.4% (298/980) for CTC and 27.4% (267/976) for FS (relative risk (RR) 1.1; 95% CI 0.98 to 1.29). Among men, participation was higher with CTC than with FS (34.1% vs 26.5%, p=0.011). In the detection RCT, 2673 subjects had FS and 2595 had CTC: the AN DR was 4.8% (127/2673, including 9 CRCs) with FS and 5.1% (133/2595, including 10 CRCs) with CTC (RR 1.08; 95% CI 0.85 to 1.37). Distal AN DR was 3.9% (109/2673) with FS and 2.9% (76/2595) with CTC (RR 0.72; 95% CI 0.54 to 0.96); proximal AN DR was 1.2% (34/2595) for FS vs 2.7% (69/2595) for CTC (RR 2.06; 95% CI 1.37 to 3.10). Participation and DR for FS and CTC were comparable. AN DR was twice as high in the proximal colon and lower in the distal colon with CTC than with FS. Men were more likely to participate in CTC screening. NCT01739608; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. CT Colonography: Pitfalls in Interpretation

    Science.gov (United States)

    Pickhardt, Perry J.; Kim, David H.

    2012-01-01

    Synopsis As with any radiologic imaging test, there are a number of potential interpretive pitfalls at CT colonography (CTC) that need to be recognized and handled appropriately. Perhaps the single most important step in learning to avoid most of these diagnostic traps is simply to be aware of their existence. With a little experience, most of these potential pitfalls will be easily recognized. This review will systematically cover the key pitfalls confronting the radiologist at CTC interpretation, primarily dividing them into those related to technique and those related to underlying anatomy. Tips and pointers for how to effectively handle these potential pitfalls are included. PMID:23182508

  14. A randomized double-blind placebo-controlled trial to evaluate the value of a single bolus intravenous alfentanil in CT colonography

    Directory of Open Access Journals (Sweden)

    Boellaard Thierry N

    2011-11-01

    Full Text Available Abstract Background Although CT colonography is a less invasive alternative for colonoscopy for the detection of colorectal polyps and cancer, procedural pain is common. In several studies, CT colonography pain and burden is higher than in colonoscopy. Apart from discomfort, anxiety and its related stress-induced peri- procedural side effects, this may influence the adherence for CT colonography as a possible screening tool for colorectal cancer. We hypothesize that a single bolus intravenous alfentanil will give a clinically relevant reduction in maximum pain defined as at least 1.3 point reduction on an 11-point numeric rating scale (NRS. Methods/Design A randomized double-blind placebo-controlled trial in which patients scheduled for elective CT colonography in a single tertiary centre are eligible for inclusion. The first 90 consenting patient will be block-randomized to either the alfentanil group or the placebo group. Before bowel insufflation, the alfentanil group receives a single bolus intravenous alfentanil 7.5 μg/kg dissolved in 0.9% NaCl, while the placebo group receives an intravenous bolus injection of pure 0.9% NaCl. For both groups an equal amount of fluid per kilogram (75 μL/kg is injected. The primary outcome is the difference in maximum pain on an 11-point NRS. Secondary outcomes include: pain and burden of different CT colonography aspects, side effects, procedural time and recovery time. For the primary outcome an independent samples t-test is performed and a P value Discussion This study will provide evidence whether a single bolus intravenous alfentanil gives a clinically relevant reduction in maximum pain during CT colonography. Trial registration Netherlands Trial Register (NTR: NTR2902 This trial will be conducted in accordance with the protocol and in compliance with the moral, ethical, and scientific principles governing clinical research as set out in the Declaration of Helsinki (1989 and Good Clinical Practice

  15. Spiral CT colonography in inflammatory bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Tarjan, Zsolt E-mail: tarjan@radi.sote.hu; Zagoni, Tamas; Gyoerke, Tamas; Mester, Adam; Karlinger, Kinga; Mako, Erno K

    2000-09-01

    Objective: Most of the studies on virtual colonoscopy are dealing with the role of detecting colorectal polyps or neoplasms. We have undertaken this study to evaluate the value of CT colonography in patients with colonic Crohn's disease. Methods and material: Five patients (three males, two females, 23-51 years, mean age 42 years) with known (4) or suspected (1) Crohn's disease of the colon underwent fiberoptic colonoscopy and CT colonography in the same day or during a 1-week period. The images were evaluated with the so called zoomed axial slice movie technique and in some regions intra- and extraluminal surface shaded and volume rendered images were generated on a separate workstation. The results were compared to those of a colonoscopy. Results: The final diagnosis was Crohn's disease in four patients and colitis ulcerosa in one. Total examination was possible by colonoscopy in two cases, and with CT colonography in all five cases. The wall of those segments severely affected by the disease were depicted by the axial CT scans to be thickened. The thick walled, segments with narrow lumen seen on CT colonography corresponded to the regions where colonoscopy was failed to pass. Air filled sinus tracts, thickening of the wall of the terminal ileum, loss of haustration pseudopolyps and deep ulcers were seen in CT colonography. Three dimensional (3D) endoluminal views demonstrated pseudopolyps similar to endoscopic images None of the colonoscopically reported shallow ulcerations or aphtoid ulcerations or granular mucosal surface were observed on 2- or 3D CT colonographic images. Conclusion: CT colonography by depicting colonic wall thickening seems to be a useful tool in the diagnosis of Crohn's colitis, which could be a single examination depicting the intraluminal, and transmural extent of the disease.

  16. Diverticular disease in CT colonography

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-12-01

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

  17. Electronic cleansing for visualization in CT colonography

    NARCIS (Netherlands)

    Serlie, I.W.O.

    2007-01-01

    In this thesis visualization and image processing methods are proposed that solve problems that are critical to the success of CT colonography; a non-invasive method to find the precursors of colon cancer. (1) A new optimal display mode was created and (2) the segmentation of the colon is enhanced.

  18. National survey of CT colonography practice in Ireland

    LENUS (Irish Health Repository)

    Smyth, A.E.

    2016-06-01

    CT Colonography was first introduced to Ireland in 1999. Our aim of this study is to review current CT Colonography practices in the Republic of Ireland. A questionnaire on CT Colonography practice was sent to all non-maternity adult radiology departments in the Republic of Ireland with a CT scanner. The results are interpreted in the context of the recommendations on CT Colonography quality standards as published by the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus statement in the journal of European Radiology in 2013. Thirty centres provide CT Colonography; 21 of which responded (70%). Each centre performs median 90 studies per year; the majority follow accepted patient preparation and image acquisition protocols. Seventy-six percent of the centres repsonded that the majority of patients imaged are symptomatic. Of the 51 consultant radiologists reading CT Colonography, 37 (73%) have attended a CT Colonography course. In 17 (81%) of the centres the studies are single read although 81% of the centres have access to a second radiologist’s opinion. Fourteen (67%) of the centres reported limited access to CT scanner time as the major limiting factor to expanding their service. CT Colonography is widely

  19. Design of a multicentre randomized trial to evaluate CT colonography versus colonoscopy or barium enema for diagnosis of colonic cancer in older symptomatic patients: The SIGGAR study

    Directory of Open Access Journals (Sweden)

    Edwards Rob

    2007-10-01

    Full Text Available Abstract Background and Aims The standard whole-colon tests used to investigate patients with symptoms of colorectal cancer are barium enema and colonoscopy. Colonoscopy is the reference test but is technically difficult, resource intensive, and associated with adverse events, especially in the elderly. Barium enema is safer but has reduced sensitivity for cancer. CT colonography ("virtual colonoscopy" is a newer alternative that may combine high sensitivity for cancer with safety and patient acceptability. The SIGGAR trial aims to determine the diagnostic efficacy, acceptability, and economic costs associated with this new technology. Methods The SIGGAR trial is a multi-centre randomised comparison of CT colonography versus standard investigation (barium enema or colonoscopy, the latter determined by individual clinician preference. Diagnostic efficacy for colorectal cancer and colonic polyps measuring 1 cm or larger will be determined, as will the physical and psychological morbidity associated with each diagnostic test, the latter via questionnaires developed from qualitative interviews. The economic costs of making or excluding a diagnosis will be determined for each diagnostic test and information from the trial and other data from the literature will be used to populate models framed to summarise the health effects and costs of alternative approaches to detection of significant colonic neoplasia in patients of different ages, prior risks and preferences. This analysis will focus particularly on the frequency, clinical relevance, costs, and psychological and physical morbidity associated with detection of extracolonic lesions by CT colonography. Results Recruitment commenced in March 2004 and at the time of writing (July 2007 5025 patients have been randomised. A lower than expected prevalence of end-points in the barium enema sub-trial has caused an increase in sample size. In addition to the study protocol, we describe our approach to

  20. Your Radiologist Explains CT Colonography

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

  1. Your Radiologist Explains CT Colonography

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  2. Your Radiologist Explains CT Colonography

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  3. Your Radiologist Explains CT Colonography

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  4. Your Radiologist Explains CT Colonography

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  5. Your Radiologist Explains CT Colonography

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

  6. CT colonography and cost-effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Mavranezouli, Ifigeneia [University College London, National Collaborating Centre for Mental Health, Centre for Outcomes Research and Effectiveness, Sub-department of Clinical Health Psychology, London (United Kingdom); East, James E. [St Marks Hospital, Imperial College London, Wolfson Unit for Endoscopy, London (United Kingdom); Taylor, Stuart A. [University College Hospital, Specialist X-Ray, London (United Kingdom); University College Hospital, Department of Imaging, London (United Kingdom)

    2008-11-15

    CT colonography (CTC) is increasingly advocated as an effective initial screening tool for colorectal cancer. Nowadays, policy-makers are increasingly interested in cost-effectiveness issues. A number of studies assessing the cost-effectiveness of CTC have been published to date. The majority of findings indicate that CTC is probably not cost-effective when colonoscopy is available, but this conclusion is sensitive to a number of key parameters. This review discusses the findings of these studies, and considers those factors which most influence final conclusions, notably intervention costs, compliance rates, effectiveness of colonoscopy, and the assumed prevalence and natural history of diminutive advanced polyps. (orig.)

  7. CT colonography: methods, pathology and pitfalls

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-03-01

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

  8. Your Radiologist Explains CT Colonography

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  9. Your Radiologist Explains CT Colonography

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    Full Text Available ... Us News Physician Resources Professions Site Index A-Z Spotlight September is National Ovarian Cancer Awareness Month ... asked to wear a gown. After the CT scan you can return to your normal diet and ...

  10. Your Radiologist Explains CT Colonography

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    Full Text Available ... a virtual colonoscopy, there are several things you can do to prepare for the examination. On the ... wear a gown. After the CT scan you can return to your normal diet and go back ...

  11. Your Radiologist Explains CT Colonography

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    Full Text Available ... is National Prostate Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) Video: Coronary CT Angiography Video: ... commonly known, virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test that is used to screen the large ...

  12. Your Radiologist Explains CT Colonography

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    Full Text Available ... is used to screen the large intestine or colon for cancer and growths called polyps. This procedure uses low-dose CT or CAT scanning to produce pictures of the colon and the rectum. During the examination, a small ...

  13. Your Radiologist Explains CT Colonography

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    Full Text Available ... to your normal diet and go back to work the same day in most cases. Perhaps you might have some concerns about CT scanning. However, it’s important to consider the likelihood of benefit from this exam to your health. While virtual colonoscopy does use radiation, the benefit ...

  14. Effect of listening to music and essential oil inhalation on patients undergoing screening CT colonography: a randomized controlled trial.

    Science.gov (United States)

    Nagata, Koichi; Iida, Nao; Kanazawa, Hidenori; Fujiwara, Masanori; Mogi, Tomohiro; Mitsushima, Toru; Lefor, Alan T; Sugimoto, Hideharu

    2014-12-01

    To prospectively evaluate the effect of listening to music and inhaling aroma oil on patients undergoing screening computed tomography colonography. Two hundred and twenty four participants were randomly allocated to one of the four groups including: (1) combined music and aroma, (2) music alone, (3) aroma alone, and (4)control. The visual analog scale for pain and a questionnaire were used for subjective outcomes. We also used a pre-test–post-test design to compare the differences in blood pressure and heart rate as objective outcomes. There were no statistical differences between the control group and other groups in the visual analog scale or changes in heart rate. Changes in blood pressure were similar. Participants reported good overall experiences. There were no differences in terms of overall satisfaction, pain rating, willingness to repeat the computed tomography colonography procedure in the future, or preference between colonoscopy and computed tomography colonography. More participants using music and/or aroma requested music and/or aroma during the next computed tomography colonography (P pain or discomfort and vital signs, participants who listened to music and inhaled aroma during the computed tomography colonography preferred music and aroma during the next computed tomography colonography. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Effect of listening to music and essential oil inhalation on patients undergoing screening CT colonography: A randomized controlled trial

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Koichi, E-mail: Nagata7@aol.com [Department of Radiology, Kameda Medical Center, 929 Higashi-cho, Kamogawa, Chiba 296-8602 (Japan); Department of Radiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan); Cancer Screening Technology Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1, Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Iida, Nao, E-mail: n.iida-xray@kameda.jp [Department of Radiology, Kameda Medical Center Makuhari, 1-3, Nakase, Mihama-ku, Chiba 261-8501 (Japan); Kanazawa, Hidenori, E-mail: r0713hk@jichi.ac.jp [Department of Radiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan); Fujiwara, Masanori, E-mail: m_fujiwara@kameda.jp [Department of Radiology, Kameda Medical Center Makuhari, 1-3, Nakase, Mihama-ku, Chiba 261-8501 (Japan); Mogi, Tomohiro, E-mail: mogi-xray@kameda.jp [Department of Radiology, Kameda Medical Center Makuhari, 1-3, Nakase, Mihama-ku, Chiba 261-8501 (Japan); Mitsushima, Toru, E-mail: mitsushima@kameda.jp [Department of Gastroenterology, Kameda Medical Center Makuhari, 1-3, Nakase, Mihama-ku, Chiba 261-8501 (Japan); Lefor, Alan T., E-mail: alefor@jichi.ac.jp [Department of Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan); Sugimoto, Hideharu, E-mail: sugimoto@jichi.ac.jp [Department of Radiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan)

    2014-12-15

    Highlights: • Music does not decrease patients’ perceived pain or acceptance during CTC. • Aromatherapy does not affect patients’ perceived pain or experience during CTC. • Music and aroma had little effect on vital signs during CTC. • More participants who listened to music requested music during the next CTC. • More participants who inhaled aroma requested aroma during the next CTC. - Abstract: Objective: To prospectively evaluate the effect of listening to music and inhaling aroma oil on patients undergoing screening computed tomography colonography. Materials and methods: Two hundred and twenty four participants were randomly allocated to one of the four groups including: (1) combined music and aroma, (2) music alone, (3) aroma alone, and (4) control. The visual analog scale for pain and a questionnaire were used for subjective outcomes. We also used a pre-test–post-test design to compare the differences in blood pressure and heart rate as objective outcomes. Results: There were no statistical differences between the control group and other groups in the visual analog scale or changes in heart rate. Changes in blood pressure were similar. Participants reported good overall experiences. There were no differences in terms of overall satisfaction, pain rating, willingness to repeat the computed tomography colonography procedure in the future, or preference between colonoscopy and computed tomography colonography. More participants using music and/or aroma requested music and/or aroma during the next computed tomography colonography (P < 0.0001). Conclusion: Although audio and olfactory intervention had little effect on perceived pain or discomfort and vital signs, participants who listened to music and inhaled aroma during the computed tomography colonography preferred music and aroma during the next computed tomography colonography.

  16. Population screening for colorectal cancer by flexible sigmoidoscopy or CT colonography: study protocol for a multicenter randomized trial.

    Science.gov (United States)

    Regge, Daniele; Iussich, Gabriella; Senore, Carlo; Correale, Loredana; Hassan, Cesare; Bert, Alberto; Montemezzi, Stefania; Segnan, Nereo

    2014-03-28

    Colorectal cancer (CRC) is the second most prevalent type of cancer in Europe. A single flexible sigmoidoscopy (FS) screening at around the age of 60 years prevents about one-third of CRC cases. However, FS screens only the distal colon, and thus mortality from proximal CRC is unaffected. Computed tomography colonography (CTC) is a highly accurate examination that allows assessment of the entire colon. However, the benefit of CTC testing as a CRC screening test is uncertain. We designed a randomized trial to compare participation rate, detection rates, and costs between CTC (with computer-aided detection) and FS as primary tests for population-based screening. An invitation letter to participate in a randomized screening trial comparing CTC versus FS will be mailed to a sample of 20,000 people aged 58 or 60 years, living in the Piedmont region and the Verona district of Italy. Individuals with a history of CRC, adenomas, inflammatory bowel disease, or recent colonoscopy, or with two first-degree relatives with CRC will be excluded from the study by their general practitioners. Individuals responding positively to the invitation letter will be then randomized to the intervention group (CTC) or control group (FS), and scheduled for the screening procedure. The primary outcome parameter of this part of the trial is the difference in advanced neoplasia detection between the two screening tests. Secondary outcomes are cost-effectiveness analysis, referral rates for colonoscopy induced by CTC versus FS, and the expected and perceived burden of the procedures. To compare participation rates for CTC versus FS, 2,000 additional eligible subjects will be randomly assigned to receive an invitation for screening with CTC or FS. In the CTC arm, non-responders will be offered fecal occult blood test (FOBT) as alternative screening test, while in the FS arm, non-responders will receive an invitation letter to undergo screening with either FOBT or CTC. Data on reasons for

  17. CT colonography practice in the UK: a national survey

    Energy Technology Data Exchange (ETDEWEB)

    Burling, D.; Halligan, S. E-mail: s.halligan@imperial.ac.uk; Taylor, S.A.; Usiskin, S.; Bartram, C.I

    2004-01-01

    AIM: To determine the provision of computed tomography (CT) colonography in UK radiology departments. MATERIALS AND METHODS: A questionnaire relating to the availability of CT colonography, barriers to implementation, clinical indications, technique, and practitioners was posted to clinical directors of UK radiology departments. RESULTS: One hundred and thirty-eight departments responded. Fifty (36%) offered CT colonography in day-to-day clinical practice. Of those that did not, 68 of 87 (64%) cited limited scanner capacity as the main barrier. Of the 50 departments offering a service, 39 (78%) offered CT after incomplete colonoscopy, 36 (72%), after failed barium enema, and 37 (74%) as an alternative to barium enema. Of those offering a service, the number of studies performed varied between one per month (38%) to more than one per day (8%). Total experience varied between 20 or fewer studies (28%) to more than 300 (12%). Full bowel preparation was common (92%), as was dual positioning (90%). Colonography was interpreted by radiologists with a subspecialty interest in gastrointestinal imaging in 64% of centres offering a service. CONCLUSION: CT colonography is widely available in the UK, with approximately one-third of responders offering a service. Experience and throughput varies considerably. Limited CT scanner capacity is the major barrier to further dissemination.

  18. CT colonography atlas. For the practicing radiologist

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele; Faggioni, Lorenzo; Bartolozzi, Carlo (eds.) [Pisa Univ. (Italy). Dept. of Diagnostic and Interventional Radiology

    2013-11-01

    Easy-to-use atlas comprising a collection of representative common and unusual virtual colonoscopy (CTC) cases that are likely to be encountered during clinical practice. Reflects the important recent advances in image acquisition, patient preparation, and image processing. An invaluable tool both for radiologists performing CTC and for clinicians who need to review the CTC examinations of their patients. This easy-to-use atlas comprises a collection of representative common and unusual virtual colonoscopy (CT colonography, CTC) cases that physicians and radiologists may expect to encounter during their clinical practice. The atlas reflects the important recent advances in image acquisition, patient preparation, and image processing and is thus completely up-to-date. Each case is presented with the native CT images, integrated images obtained by 3D image processing, and colonoscopic correlation. Topics covered include normal appearances, anatomical variants, pitfalls, diverticula, lipomas, inflammatory bowel disease, polyps, flat lesions, cancers, and the postsurgical colon. By presenting the main features of anatomy and pathology, this atlas will serve as an invaluable tool both for radiologists performing CTC and for clinicians who need to review the CTC examinations of their patients.

  19. Small animal micro-CT colonography.

    Science.gov (United States)

    Durkee, Benjamin Y; Weichert, Jamey P; Halberg, Richard B

    2010-01-01

    Microcomputed tomography colonography (mCTC) is a new method for detecting colonic tumors in living animals and estimating their volume, which allows investigators to determine the spontaneous fate of individually annotated tumors as well as their response to chemotherapeutics. This imaging platform was developed using the Min mouse, but is applicable to any murine model of human colorectal cancer. MicroCT is capable of 20 micron resolution, however, 100 microns is sufficient for this application. Scan quality is primarily dependent on animal preparation with the most critical parameters being proper anesthesia, bowel cleansing, and sufficient insufflation. The detection of colonic tumors is possible by both 2D and 3D rendering of image data. Tumor volume is estimated using a semi-automated five-step process which is based on three algorithms within the Amira software package. The estimates are precise, accurate and reproducible enabling changes in volume as small as 16% to be readily observed. Confirmation of mCTC observations by gross examination and histology is sometimes useful in this otherwise non-invasive protocol. Finally, mCTC is compared to other newly developed small animal imaging platforms including microMRI and microoptical colonoscopy. A major advantage of these platforms is that investigators can be perform longitudinal studies, which often have much greater statistical power than traditional cross-sectional studies; consequently, fewer animals are required for testing.

  20. CT colonography: effect of experience and training on reader performance

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Stuart A.; Burling, David; Morley, Simon; Bartram, Clive I. [Department of Intestinal Imaging, St. Mark' s Hospital, Watford Road, Northwick Park, HA1 3UJ, London (United Kingdom); Halligan, Steve [Department of Intestinal Imaging, St. Mark' s Hospital, Watford Road, Northwick Park, HA1 3UJ, London (United Kingdom); Department of Cancer Research UK Colorectal Cancer Unit, St. Mark' s Hospital, Northwick Park, HA1 3UJ, London (United Kingdom); Bassett, Paul [Department of Statistics, St. Mark' s Hospital, Northwick Park, HA1 3UJ, London (United Kingdom); Atkin, Wendy [Department of Cancer Research UK Colorectal Cancer Unit, St. Mark' s Hospital, Northwick Park, HA1 3UJ, London (United Kingdom)

    2004-06-01

    The purpose of this paper was to investigate the effect of radiologist experience and increasing exposure to CT colonography on reader performance. Three radiologists of differing general experience (consultant, research fellow, trainee) independently analysed 100 CT colonographic datasets. Readers had no prior experience of CT colonography and received feedback and training after the first 50 cases from an independent experienced radiologist. Diagnostic performance and reporting times were compared for the first and second 50 datasets and compared with the results of a radiologist experienced in CT colonography. Before training only the consultant reader achieved statistical equivalence with the reference standard for detection of larger polyps. After training, detection rates ranged between 25 and 58% for larger polyps. Only the trainee significantly improved after training (P=0.007), with performance of other readers unchanged or even worse. Reporting times following training were reduced significantly for the consultant and fellow (P<0.001 and P=0.03, respectively), but increased for the trainee (P<0.001). In comparison to the consultant reader, the odds of detection of larger polyps was 0.36 (CI 0.16, 0.82) for the fellow and 0.36 (CI 0.14, 0.91) for the trainee. There is considerable variation in the ability to report CT colonography. Prior experience in gastrointestinal radiology is a distinct advantage. Competence cannot be assumed even after directed training via a database of 50 cases. (orig.)

  1. Computer Aided Detection of Polyps in CT Colonography

    NARCIS (Netherlands)

    Van Ravesteijn, V.F.

    2013-01-01

    CT colonography (CTC) is a minimally invasive method for detection of colorectal polyps and colon cancer. Limitations of CTC related to the efficiency as well as the sensitivity of radiologists. Additionally, the patient's preparation was considered burdensome and the X-ray radiation that is inheren

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-15

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

  3. Complications of CT colonography: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Pendsé, D.A., E-mail: mail@dougpendse.com [Department of Imaging, University College London Hospitals NHS Foundation Trust, London (United Kingdom); Department of Medical Imaging, University College London, 250 Euston Rd (United Kingdom); Taylor, S.A., E-mail: csytaylor@yahoo.co.uk [Department of Imaging, University College London Hospitals NHS Foundation Trust, London (United Kingdom); Department of Medical Imaging, University College London, 250 Euston Rd (United Kingdom)

    2013-08-15

    Since its inception, one of the main advantages of computed tomography colonography (CTC) over colonoscopy has been its assumed superior safety profile. However CTC is not without complication and adverse events are well described. Although the risks of insufflation, bowel preparation, contrast media and radiation dose are very small, they are not insignificant. This review discusses the potential hazards and complications associated with the technique, and discuss precautions, which may lessen the risk of occurrence.

  4. CT colonography with computer-aided detection: recognizing the causes of false-positive reader results.

    Science.gov (United States)

    Trilisky, Igor; Wroblewski, Kristen; Vannier, Michael W; Horne, John M; Dachman, Abraham H

    2014-01-01

    Computed tomography (CT) colonography is a screening modality used to detect colonic polyps before they progress to colorectal cancer. Computer-aided detection (CAD) is designed to decrease errors of detection by finding and displaying polyp candidates for evaluation by the reader. CT colonography CAD false-positive results are common and have numerous causes. The relative frequency of CAD false-positive results and their effect on reader performance on the basis of a 19-reader, 100-case trial shows that the vast majority of CAD false-positive results were dismissed by readers. Many CAD false-positive results are easily disregarded, including those that result from coarse mucosa, reconstruction, peristalsis, motion, streak artifacts, diverticulum, rectal tubes, and lipomas. CAD false-positive results caused by haustral folds, extracolonic candidates, diminutive lesions (reader false-positive results. Nondismissable CAD soft-tissue polyp candidates larger than 6 mm are another common cause of reader false-positive results that may lead to further evaluation with follow-up CT colonography or optical colonoscopy. Strategies for correctly evaluating CAD polyp candidates are important to avoid pitfalls from common sources of CAD false-positive results. ©RSNA, 2014.

  5. Role of CT colonography in inflammatory bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Regge, Daniele [Institute for Cancer Research and Treatment, Candiolo, Turin (Italy)], E-mail: dregge@mauriziano.it; Neri, Emanuele; Turini, Francesca [Diagnostic and Interventional Radiology, University of Pisa (Italy); Chiara, Gabriele [Institute for Cancer Research and Treatment, Candiolo, Turin (Italy)

    2009-03-15

    CT colonography (CTC), or virtual colonoscopy, is a non-invasive imaging method that uses CT data sets combined with specialized imaging software to examine the colon. CTC is not used routinely in patients with inflammatory bowel disease (IBD). However, investigating contemporarily the colon, other abdominal organs and the peritoneum with CTC is at times useful in patients with IBD, especially when other diagnostic tools fail. Furthermore, since symptoms of colorectal cancer sometimes superimpose to those of inflammatory disease, it may happen to image patients with IBD incidentally. If clinical signs are suggestive for inflammatory disease, exam technique should be modified accordingly and distinguishing radiological findings searched for.

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

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Margriet C. de [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Academic Medical Center, Amsterdam, Department of Radiology, G1-223.1, Amsterdam (Netherlands); Gelder, Rogier E. van; Bipat, Shandra; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Graser, Anno [University of Munich, Department of Clinical Radiology, Klinikum Grosshadern, Munich (Germany)

    2011-08-15

    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 (<1% high risk). I{sup 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.)

  7. Improving Polyp Detection Algorithms for CT Colonography: Pareto Front Approach.

    Science.gov (United States)

    Huang, Adam; Li, Jiang; Summers, Ronald M; Petrick, Nicholas; Hara, Amy K

    2010-03-21

    We investigated a Pareto front approach to improving polyp detection algorithms for CT colonography (CTC). A dataset of 56 CTC colon surfaces with 87 proven positive detections of 53 polyps sized 4 to 60 mm was used to evaluate the performance of a one-step and a two-step curvature-based region growing algorithm. The algorithmic performance was statistically evaluated and compared based on the Pareto optimal solutions from 20 experiments by evolutionary algorithms. The false positive rate was lower (pPareto optimization process can effectively help in fine-tuning and redesigning polyp detection algorithms.

  8. Polyp measurement based on CT colonography and colonoscopy: variability and systematic differences

    Energy Technology Data Exchange (ETDEWEB)

    Vries, Ayso H. de; Bipat, Shandra; Liedenbaum, Marjolein H.; Florie, Jasper; Vos, Frans M.; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Dekker, Evelien; Fockens, Paul; Mathus-Vliegen, Elizabeth M. [University of Amsterdam, Department of Gastroenterology, Academic Medical Centre, Amsterdam (Netherlands); Kraan, Roel van der; Truyen, Roel [Philips Healthcare, Department of Healthcare Informatics, Best (Netherlands); Reitsma, Johannes B.; Zwinderman, Aeilko H. [University of Amsterdam, Department of Clinical Epidemiology and Biostatistics, Amsterdam Medical Center, Amsterdam (Netherlands)

    2010-06-15

    To assess the variability and systematic differences in polyp measurements on optical colonoscopy and CT colonography. Gastroenterologists measured 51 polyps by visual estimation, forceps comparison and linear probe. CT colonography observers randomly assessed polyp size two-dimensionally (abdominal and intermediate window) and three-dimensionally (manually and semi-automatically). Linear mixed models were used to assess the variability and systematic differences between CT colonography and optical colonoscopy techniques. The variability of forceps and linear probe measurements was comparable and both showed less variability than measurement by visual assessment. Measurements by linear probe were 0.7 mm smaller than measurements by visual assessment or by forceps. The variability of all CT colonography techniques was lower than for measurements by forceps or visual assessment and sometimes lower (only 2D intermediate window and manual 3D) compared with measurements by linear probe. All CT colonography measurements judged polyps to be larger than optical colonoscopy, with differences ranging from 0.7 to 2.3 mm. A linear probe does not reduce the measurement variability of endoscopists compared with the forceps. Measurement differences between observers on CT colonography were usually smaller than at optical colonoscopy. Polyps appeared larger when using various CT colonography techniques than when measured during optical colonoscopy. (orig.)

  9. Quantification of distention in CT colonography: development and validation of three computer algorithms.

    Science.gov (United States)

    Hung, Peter W; Paik, David S; Napel, Sandy; Yee, Judy; Jeffrey, R Brooke; Steinauer-Gebauer, Andreas; Min, Juno; Jathavedam, Ashwin; Beaulieu, Christopher F

    2002-02-01

    Three bowel distention-measuring algorithms for use at computed tomographic (CT) colonography were developed, validated in phantoms, and applied to a human CT colonographic data set. The three algorithms are the cross-sectional area method, the moving spheres method, and the segmental volume method. Each algorithm effectively quantified distention, but accuracy varied between methods. Clinical feasibility was demonstrated. Depending on the desired spatial resolution and accuracy, each algorithm can quantitatively depict colonic diameter in CT colonography.

  10. Teleradiology based CT colonography to screen a population group of a remote island; at average risk for colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lefere, Philippe, E-mail: radiologie@skynet.be [VCTC, Virtual Colonoscopy Teaching Centre, Akkerstraat 32c, B-8830 Hooglede (Belgium); Silva, Celso, E-mail: caras@uma.pt [Human Anatomy of Medical Course, University of Madeira, Praça do Município, 9000-082 Funchal (Portugal); Gryspeerdt, Stefaan, E-mail: stefaan@sgryspeerdt.be [VCTC, Virtual Colonoscopy Teaching Centre, Akkerstraat 32c, B-8830 Hooglede (Belgium); Rodrigues, António, E-mail: nucleo@nid.pt [Nucleo Imagem Diagnostica, Rua 5 De Outubro, 9000-216 Funchal (Portugal); Vasconcelos, Rita, E-mail: rita@uma.pt [Department of Engineering and Mathematics, University of Madeira, Praça do Município, 9000-082 Funchal (Portugal); Teixeira, Ricardo, E-mail: j.teixeira1947@gmail.com [Department of Gastroenterology, Central Hospital of Funchal, Avenida Luís de Camões, 9004513 Funchal (Portugal); Gouveia, Francisco Henriques de, E-mail: fhgouveia@netmadeira.com [LANA, Pathology Centre, Rua João Gago, 10, 9000-071 Funchal (Portugal)

    2013-06-15

    Purpose: To prospectively assess the performance of teleradiology-based CT colonography to screen a population group of an island, at average risk for colorectal cancer. Materials and methods: A cohort of 514 patients living in Madeira, Portugal, was enrolled in the study. Institutional review board approval was obtained and all patients signed an informed consent. All patients underwent both CT colonography and optical colonoscopy. CT colonography was interpreted by an experienced radiologist at a remote centre using tele-radiology. Per-patient sensitivity, specificity, positive (PPV) and negative (NPV) predictive values with 95% confidence intervals (95%CI) were calculated for colorectal adenomas and advanced neoplasia ≥6 mm. Results: 510 patients were included in the study. CT colonography obtained a per-patient sensitivity, specificity, PPV and, NPV for adenomas ≥6 mm of 98.11% (88.6–99.9% 95% CI), 90.97% (87.8–93.4% 95% CI), 56.52% (45.8–66.7% 95% CI), 99.75% (98.4–99.9% 95% CI). For advanced neoplasia ≥6 mm per-patient sensitivity, specificity, PPV and, NPV were 100% (86.7–100% 95% CI), 87.07% (83.6–89.9% 95% CI), 34.78% (25.3–45.5% 95% CI) and 100% (98.8–100% 95% CI), respectively. Conclusion: In this prospective trial, teleradiology-based CT colonography was accurate to screen a patient cohort of a remote island, at average risk for colorectal cancer.

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

    Directory of Open Access Journals (Sweden)

    Devir

    2016-01-01

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

  12. Insurance Coverage for CT Colonography Screening: Impact on Overall Colorectal Cancer Screening Rates.

    Science.gov (United States)

    Smith, Maureen A; Weiss, Jennifer M; Potvien, Aaron; Schumacher, Jessica R; Gangnon, Ronald E; Kim, David H; Weeth-Feinstein, Lauren A; Pickhardt, Perry J

    2017-09-01

    Purpose To compare overall colorectal cancer (CRC) screening rates for patients who were eligible and due for CRC screening and who were with and without insurance coverage for computed tomographic (CT) colonography for CRC screening. Materials and Methods The institutional review board approved this retrospective cohort study, with a waiver of consent. This study used longitudinal electronic health record data from 2005 through 2010 for patients managed by one of the largest multispecialty physician groups in the United States. It included 33 177 patients under age 65 who were eligible and due for CRC screening and managed by the participating health system. Stratified Cox regression models provided propensity-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the relationship between CT colonography coverage and CRC screening. Results After adjustment, patients who had insurance coverage for CT colonography and were due for CRC screening had a 48% greater likelihood of being screened for CRC by any method compared with those without coverage who were due for CRC screening (HR, 1.48; 95% CI: 1.41, 1.55). Similarly, patients with CT colonography coverage had a greater likelihood of being screened with CT colonography (HR, 8.35; 95% CI: 7.11, 9.82) and with colonoscopy (HR, 1.38; 95% CI: 1.31, 1.45) but not with fecal occult blood test (HR, 1.00; 95% CI: 0.91, 1.10) than those without such insurance coverage. Conclusion Insurance coverage of CT colonography for CRC screening was associated with a greater likelihood of a patient being screened and a greater likelihood of being screened with a test that helps both to detect cancer and prevent cancer from developing (CT colonography or colonoscopy). (©) RSNA, 2017.

  13. USING OF MULTISLICE HELICAL CT COLONOGRAPHY IN PATIENTS WITH MALIGNANT LESIONS OF COLON

    Institute of Scientific and Technical Information of China (English)

    Ming-wei Qin; Wei-dong Pan; Guan-ning Cong; Yun Wang; Yun-qing Zhang; Wen-bin Mou; Zheng-yu Jin

    2005-01-01

    Objective To investigate the techniques and clinical applications of multislice helical computed tomography (CT) colono graphy in colonic lesions. Methods Fifty-nine patients with malignant lesions of colon underwent volume scanning using multislice helical CT. Four types of reconstruction including CT virtual colonoscopy (CTVC), shaded surface display (SSD), Raysum, and mu ltiple planar reconstruction (MPR) were used for image post-processing. The results were compared with those of colonos copy and pathology. Results Multislice helical CT colonography detected 54 colorectal carcinomas, 4 adenomas with focal carcinoma, 1 non-Hodgkin's lymphoma (NHL). The lesions' number, size, location, morphology, stricture of intestinal cavity, infiltration, and metastasis were shown satisfactorily by multislice helical CT colonography. Whole colon could be shown in all patients. CT colonography displayed 4 synchronous colonic tumors, 1 ascending colon carcinoma combined with left renal carcinoma among 54 patients with colonic carcinomas. The accuracy of location of CT colonography was 100%. There were 9 cases that CT showed the tumor location was different from the finding of conventional colonoscopy, while all of the CT location were proven exact by operation. CT colonography also displayed the infiltration of serous layer and fatty tissue in 45 cases; 21 cases matched the pathological results in all the 24 cases of suspicious lymph node metastasis, the sensitivity was 87.5%, the specificity was 90.6%; 9 cases hepatic metastasis, 2 ovarian metastasis, and 1 double adrenal gland metastasis.Conclusions Multislice helical CT colonography is effective in preoperative diagnosis, location, stage, and making treatment plan of colorectal carcinoma. It can display the portion not seen during colonoscopy and may have an adjunctive role.

  14. Postprocessing techniques of CT colonography in detection of colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Ming-Yue Luo; Hong Shan; Li-Qing Yao; Kang-Rong Zhou; Wen-Wei Liang

    2004-01-01

    AIM: To evaluate the value of postprocessing techniques of CT colonography, including multiplanar reformation (MPR),virtual colonoscopy (VC), shaded surface display (SSD) and Raysum, in detection of colorectal carcinomas.METHODS: Sixty-four patients with colorectal carcinoma underwent volume scanning with spiral CT. MPR, VC, SSD and Raysum images were obtained by using four kinds of postprocessing techniques in workstation. The results were comparatively analyzed according to circumferential extent,lesion length and pathology pattern of colorectal carcinomas.All diagnoses were proved pathologically and surgically.RESULTS: The accuracy of circumferential extent of colorectal carcinoma determined by MPR, VC, SSD and Raysum was 100.0%, 82.8%, 79.7% and 79.7%,respectively. There was a significant statistical difference between MPR and VC. The consistent rate of lesion length was 89.1%, 76.6%, 95.3% and 100.0%, respectively.There was a statistical difference between VC and SSD.The accuracy of discriminating pathology pattern was 81.3%,92.2%, 71.9% and 71.9%, respectively. There was a statistical difference between VC and SSD. MPR could determine accurately the circumference of colorectal carcinoma, Raysum could determine the length of lesion more precisely than SSD, VC was helpful in discriminating pathology patterns.CONCLUSION: MPR, VC, SSD and Raysum have advantage and disadvantage in detection of colorectal carcinoma, use of these methods in combination can disclose the lesion more accurately.

  15. Assessment of the efficacy of the education of radiographers who interpret CT-colonography examinations

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Ammitzbøl; Jeppesen, Lau; Westphal, Lena

    2014-01-01

    diagnostic modalities are used for colonic evaluation including rectoscopy, flexible sigmoideoscopy, OC, fecal occult blood test, double contrast barium enema, magnetic resonance colonography and CTC. However, OC is considered to be the gold standard due to a high diagnostic accuracy and the option......) display techniques. The examination was first introduced in 1994 by Vinning,11 and since the introduction there have been further advancements in CTC technology. Multi detector CT now permits image acquisition of thin 1‐ to 2‐mm slices of the entire large intestine, well within breath‐hold imaging times......‐center trial reported excellent sensitivity for large adenomas and cancers.17 A further study by Kim et al., compared the diagnostic yield from parallel OC and CTC screening programs and found similar detection rates of advanced neoplasia in the two groups.18 Some studies have documented wide inter...

  16. CT colonography and transient bacteraemia: implications for antibiotic prophylaxis

    Energy Technology Data Exchange (ETDEWEB)

    Ridge, C.A.; Carter, M.R.; Ryan, R.; Hegarty, C.; Malone, D.E. [St Vincent' s University Hospital, Department of Radiology, Dublin 4 (Ireland); Browne, L.P. [Texas Children' s Hospital, Department of Diagnostic Imaging, Houston, TX (United States); Schaffer, K. [St Vincent' s University Hospital, Department of Microbiology, Dublin 4 (Ireland)

    2011-02-15

    To determine the prevalence of transient bacteraemia after CT colonography (CTC). Blood cultures were obtained at 5, 10 and 15 min after CTC from 100 consecutive consenting patients. Blood samples were cultured in both aerobic and anaerobic media and positive blood culture samples were analysed by a microbiologist. Blood culture samples were positive for growth in sixteen patients. All positive blood culture samples were confirmed skin contaminants. There were no cases of significant bacteraemia. The estimated significant bacteraemia rate as a result of CTC is 0-3.7%, based on 95% confidence intervals around extreme results using Wilson's score method. American Heart Association and National Institute for Clinical Excellence guidelines advise that antibiotic prophylaxis before lower gastrointestinal endoscopy is not indicated in patients with at risk cardiac lesions (ARCL) as the risk of a transient bacteraemia leading to infective endocarditis is low. These data show that the prevalence of transient bacteraemia after CTC is also low. It follows that patients with ARCL do not require antibiotic prophylaxis before CTC. (orig.)

  17. CT colonography and transient bacteraemia: implications for antibiotic prophylaxis.

    LENUS (Irish Health Repository)

    Ridge, C A

    2012-02-01

    OBJECTIVES: To determine the prevalence of transient bacteraemia after CT colonography (CTC). METHODS: Blood cultures were obtained at 5, 10 and 15 min after CTC from 100 consecutive consenting patients. Blood samples were cultured in both aerobic and anaerobic media and positive blood culture samples were analysed by a microbiologist. RESULTS: Blood culture samples were positive for growth in sixteen patients. All positive blood culture samples were confirmed skin contaminants. There were no cases of significant bacteraemia. The estimated significant bacteraemia rate as a result of CTC is 0-3.7%, based on 95% confidence intervals around extreme results using Wilson\\'s score method. CONCLUSIONS: American Heart Association and National Institute for Clinical Excellence guidelines advise that antibiotic prophylaxis before lower gastrointestinal endoscopy is not indicated in patients with at risk cardiac lesions (ARCL) as the risk of a transient bacteraemia leading to infective endocarditis is low. These data show that the prevalence of transient bacteraemia after CTC is also low. It follows that patients with ARCL do not require antibiotic prophylaxis before CTC.

  18. Distributed human intelligence for colonic polyp classification in computer-aided detection for CT colonography.

    Science.gov (United States)

    Nguyen, Tan B; Wang, Shijun; Anugu, Vishal; Rose, Natalie; McKenna, Matthew; Petrick, Nicholas; Burns, Joseph E; Summers, Ronald M

    2012-03-01

    To assess the diagnostic performance of distributed human intelligence for the classification of polyp candidates identified with computer-aided detection (CAD) for computed tomographic (CT) colonography. This study was approved by the institutional Office of Human Subjects Research. The requirement for informed consent was waived for this HIPAA-compliant study. CT images from 24 patients, each with at least one polyp of 6 mm or larger, were analyzed by using CAD software to identify 268 polyp candidates. Twenty knowledge workers (KWs) from a crowdsourcing platform labeled each polyp candidate as a true or false polyp. Two trials involving 228 KWs were conducted to assess reproducibility. Performance was assessed by comparing the area under the receiver operating characteristic curve (AUC) of KWs with the AUC of CAD for polyp classification. The detection-level AUC for KWs was 0.845 ± 0.045 (standard error) in trial 1 and 0.855 ± 0.044 in trial 2. These were not significantly different from the AUC for CAD, which was 0.859 ± 0.043. When polyp candidates were stratified by difficulty, KWs performed better than CAD on easy detections; AUCs were 0.951 ± 0.032 in trial 1, 0.966 ± 0.027 in trial 2, and 0.877 ± 0.048 for CAD (P = .039 for trial 2). KWs who participated in both trials showed a significant improvement in performance going from trial 1 to trial 2; AUCs were 0.759 ± 0.052 in trial 1 and 0.839 ± 0.046 in trial 2 (P = .041). The performance of distributed human intelligence is not significantly different from that of CAD for colonic polyp classification. © RSNA.

  19. Current status on performance of CT colonography and clinical indications

    Energy Technology Data Exchange (ETDEWEB)

    Laghi, Andrea, E-mail: andrea.laghi@uniroma1.it [Department of Radiological Sciences, Oncology and Pathology Sapienza – Università di Roma, Polo Pontino, I.C.O.T. Hospital, Via Franco Faggiana 43, 04100 Latina (Italy); Rengo, Marco [Department of Radiological Sciences, Oncology and Pathology Sapienza – Università di Roma, Polo Pontino, I.C.O.T. Hospital, Via Franco Faggiana 43, 04100 Latina (Italy); Graser, Anno [InstitutfürKlinische Radiologie, Klinikumder Ludwig-Maximilians-Universität München, Campus Großhadern, Marchioninistr. 15, 81377 München (Germany); Iafrate, Franco [Department of Radiological Sciences, Oncology and Pathology Sapienza – Università di Roma, Policlinico Umberto I, Viale Regina Elena 324, 00161 Rome (Italy)

    2013-08-15

    CT colonography (CTC) is a robust and reliable imaging test of the colon. Accuracy for the detection of colorectal cancer (CRC) is as high as conventional colonoscopy (CC). Identification of polyp is size dependent, with large lesions (≥10 mm) accurately detected and small lesions (6–9 mm) identified with moderate to good sensitivity. Recent studies show good sensitivity for the identification of nonpolypoid (flat) lesions as well. Current CTC indications include the evaluation of patients who had undergone a previous incomplete CC or those who are unfit for CC (elderly and frail individuals, patients with underlying severe clinical conditions, or with contraindication to sedation). CTC can also be efficiently used in the assessment of diverticular disease (excluding patients with acute diverticulitis, where the exam should be postponed), before laparoscopic surgery for CRC (to have an accurate localization of the lesion), in the evaluation of colonic involvement in the case of deep pelvic endometriosis (replacing barium enema). CTC is also a safe procedure in patients with colostomy. For CRC screening, CTC should be considered an opportunistic screening test (not available for population, or mass screening) to be offered to asymptomatic average-risk individuals, of both genders, starting at age 50. The use in individuals with positive family history should be discussed with the patient first. Absolute contraindication is to propose CTC for surveillance of genetic syndromes and chronic inflammatory bowel diseases (in particular, ulcerative colitis). The use of CTC in the follow-up after surgery for CRC is achieving interesting evidences despite the fact that literature data are still relatively weak in terms of numerosity of the studied populations. In patients who underwent previous polypectomy CTC cannot be recommended as first test because debate is still open. It is desirable that in the future CTC would be the first-line and only diagnostic test for

  20. Haustral loop extraction for CT colonography using geodesics.

    Science.gov (United States)

    Liu, Yongkai; Duan, Chaijie; Liang, Jerome; Hu, Jing; Lu, Hongbing; Luo, Mingyue

    2017-03-01

    The human colon has complex geometric structures because of its haustral folds, which are thin flat protrusions on the colon wall. The haustral loop is the curve (approximately triangular in shape) that encircles the highly convex region of the haustral fold, and is regarded as the natural landmark of the colon, intersecting the longitude of the colon in the middle. Haustral loop extraction can assist in reducing the structural complexity of the colon, and the loops can also serve as anatomic markers for computed tomographic colonography (CTC). Moreover, haustral loop sectioning of the colon can help with the performance of precise prone-supine registration. We propose an accurate approach of extracting haustral loops for CT virtual colonoscopy based on geodesics. First, the longitudinal geodesic (LG) connecting the start and end points is tracked by the geodesic method and the colon is cut along the LG. Second, key points are extracted from the LG, after which paired points that are used for seeking the potential haustral loops are calculated according to the key points. Next, for each paired point, the shortest distance (geodesic line) between the paired points twice is calculated, namely one on the original surface and the other on the cut surface. Then, the two geodesics are combined to form a potential haustral loop. Finally, erroneous and nonstandard potential loops are removed. To evaluate the haustral loop extraction algorithm, we first utilized the algorithm to extract the haustral loops. Then, we let the clinicians determine whether the haustral loops were correct and then identify the missing haustral loops. The extraction algorithm successfully detected 91.87% of all of the haustral loops with a very low false positive rate. We believe that haustral loop extraction may benefit many post-procedures in CTC, such as supine-prone registration, computer-aided diagnosis, and taenia coli extraction.

  1. Positive predictive value for polyps detected at screening CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Pickhardt, Perry J.; Wise, Steven M.; Kim, David H. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States)

    2010-07-15

    To determine the positive predictive value (PPV) for polyps detected at CT colonography (CTC). Assessment of 739 colorectal lesions {>=}6 mm detected prospectively at CTC screening in 479 patients was performed. By-polyp PPV was analyzed according to small (6-9 mm) versus large ({>=}10 mm) size; morphology (sessile/pedunculated/flat); diagnostic confidence level (3 = most confident, 1 = least confident); and histology. By-patient PPV was analyzed at various polyp size thresholds. By-polyp PPV for CTC-detected lesions {>=}6 mm, 6-9 mm, and {>=}10 mm was 91.6% (677/739), 90.1% (410/451), and 92.7% (267/288), respectively (p = 0.4). By-polyp PPV according to sessile, pedunculated, flat, and mass-like morphology was 92.5% (441/477), 96.5% (139/144), 77.7% (73/94), and 97.6% (40/41), respectively (p < 0.0001 for flat versus polypoid morphology). By-polyp PPV according to diagnostic confidence level was 94.7% (554/585) for highest (= level 3), 83.5% (106/127) for intermediate (= level 2), and 63.0% (17/27) for lowest (= level 1) confidence (p < 0.0001 for levels-2/3 versus level-1). By-patient PPV at 6-mm, 8-mm, 10-mm, and 30-mm polyp size thresholds was 92.3% (442/479), 93.0% (306/329), 93.1% (228/245), and 97.4% (38/39), respectively. The overall per-polyp and per-patient PPV for lesions {>=}6 mm was 92% for CTC screening. Increased diagnostic confidence and polypoid (non-flat) morphology correlated with a higher PPV, whereas small versus large polyp size had very little effect. (orig.)

  2. Limited-preparation CT colonography in frail elderly patients: a feasibility study.

    LENUS (Irish Health Repository)

    Keeling, Aoife N

    2010-05-01

    Full colonic preparation can be onerous and may be poorly tolerated in frail elderly patients. The purpose of this study was to prospectively assess the image quality and diagnostic yield of limited-preparation CT colonography (CTC) in elderly patients with suspected colorectal cancer who were deemed medically unfit or unsuitable for colonoscopy.

  3. Effect of a Tele-Training Program on Radiographers in the Interpretation of CT-Colonography

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Ammitzbøl; Gerke, Oke; Gryspeerdt, Stefaan

    2011-01-01

    Objective: To assess the performance of radiographers in CT Colonography (CTC) after a tele-training programme, supervised by 2 experienced radiologists. Material and methods Five radiographers underwent training in CTC using a tele-training programme mainly based on the interpretation of 75...

  4. Bowel preparation in CT colonography: electrolyte and renal function disturbances in the frail and elderly patient.

    LENUS (Irish Health Repository)

    Mc Laughlin, Patrick

    2010-03-01

    Elderly patients are at increased risk of biochemical disturbances secondary to cathartic medications. This study investigates the renal function, electrolyte and clinical disturbances associated with CT colonography (CTC) with sodium picosulphate-magnesium citrate (SPS-MC) in a subgroup of frail, elderly patients.

  5. Performance of CT Colonography for Detecting Small Diminutive and Flat Polyps

    Science.gov (United States)

    2010-04-01

    CT colonography with pig colonic specimens. Radiology 2007;244(1):157–64. 47. Pickhardt PJ, Kim DH, Cash BD, et al. The natural history of small...determined by back-to-back colonoscopies. Gastroenterology 1997;112(1):24–8. 61. Lefere PA, Gryspeerdt SS, Dewyspelaere J, et al. Dietary fecal tagging as a

  6. Efficacy of IV Buscopan as a muscle relaxant in CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzi, John F.; Brennan, Darren D.; Fenlon, Helen M. [Department of Radiology, Mater Misericordiae Hospital, Eccles Street, Dublin 7 (Ireland); Moss, Alan C.; MacMathuna, Padraic [Department of Gastroenterology, Mater Misericordiae Hospital, Eccles Street, Dublin 7 (Ireland)

    2003-10-01

    The aim of this study was to examine the efficacy of IV Buscopan as a muscle relaxant in CT colonography in terms of colonic distension and polyp detection, and to determine its particular efficacy in patients with diverticular disease. Seventy-three consecutive patients were randomised to receive IV Buscopan or no muscle relaxant prior to CT colonography. CT colonography was performed using a Siemens Somatom 4-detector multislice CT scanner. The following parameters were recorded: degree of colonic distension using a 4-point scale; diagnostic adequacy of colonic distension; presence or absence of diverticular disease; and presence of colonic polyps. Accuracy of polyp detection was assessed using subsequent conventional colonoscopy as a gold standard. There was no significant difference between the two groups in the number of segments that were deemed to be optimally or adequately distended (p=0.37). Although IV Buscopan did improve distension of certain segments, this effect was not sufficient to improve the number of diagnostically adequate studies in the Buscopan group (p=0.14). In patients with diverticular disease, IV Buscopan did not have any significant effect on segments affected by diverticulosis but was associated with an improvement in distension of more proximal segments. There was no significant difference between the two groups in terms of polyp detection (p=0.34). The addition of prone scanning to supine scanning was found to be the most useful technique for maximising colonic distension. Intravenous Buscopan at CT colonography does not improve the overall adequacy of colonic distension nor the accuracy of polyp detection. In patients with sigmoid diverticular disease IV Buscopan improves distension of more proximal colonic segments and may be useful in selected cases, but our results do not support its routine use for CT colonography. (orig.)

  7. 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.)

  8. Intra-individual comparison of patient acceptability of multidetector-row CT colonography and double-contrast barium enema

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.A. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom)]. E-mail: csytaylor@yahoo.co.uk; Halligan, S. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom); Burling, D. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom); Bassett, P. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom); Bartram, C.I. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom)

    2005-02-01

    AIMS: To compare the subjective acceptability of CT colonography in comparison with barium enema in older symptomatic patients, and to ascertain preferences for future colonic investigation. MATERIALS AND METHODS: The study population comprised 78 persons aged 60 years or over with symptoms suggestive of colorectal neoplasia, who underwent CT colonography followed the same day by barium enema. A 25-point questionnaire was administered after each procedure and an additional follow-up questionnaire a week later. Responses were compared using Wilcoxon matched pairs testing, Mann-Whitney test statistics and binomial exact testing. RESULTS: Participants suffered less physical discomfort during CT colonography (p=0.03) and overall satisfaction was greater compared with barium enema (p=0.03). On follow-up, respondents reported significantly better tolerance of CT colonography (p=0.002), and were less prepared to undergo barium enema again (p<0.001). Of 52 subjects expressing an opinion, all preferred CT to barium enema. CONCLUSION: Patient satisfaction was higher with CT colonography than barium enema. CT colonography caused significantly less physical discomfort and was overwhelmingly preferred by patients.

  9. Segmentation algorithm of colon based on multi-slice CT colonography

    Science.gov (United States)

    Hu, Yizhong; Ahamed, Mohammed Shabbir; Takahashi, Eiji; Suzuki, Hidenobu; Kawata, Yoshiki; Niki, Noboru; Suzuki, Masahiro; Iinuma, Gen; Moriyama, Noriyuki

    2012-02-01

    CT colonography is a radiology test that looks at people's large intestines(colon). CT colonography can screen many options of colon cancer. This test is used to detect polyps or cancers of the colon. CT colonography is safe and reliable. It can be used if people are too sick to undergo other forms of colon cancer screening. In our research, we proposed a method for automatic segmentation of the colon from abdominal computed Tomography (CT) images. Our multistage detection method extracted colon and spited colon into different parts according to the colon anatomy information. We found that among the five segmented parts of the colon, sigmoid (20%) and rectum (50%) are more sensitive toward polyps and masses than the other three parts. Our research focused on detecting the colon by the individual diagnosis of sigmoid and rectum. We think it would make the rapid and easy diagnosis of colon in its earlier stage and help doctors for analysis of correct position of each part and detect the colon rectal cancer much easier.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-15

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

  11. Colorectal cancer screening:The role of CT colonography

    Institute of Scientific and Technical Information of China (English)

    Andrea; Laghi; Franco; Iafrate; Marco; Rengo; Cesare; Hassan

    2010-01-01

    Computed tomography colonography(CTC) in colorectal cancer(CRC) screening has two roles:one present and the other potential.The present role is,without any further discussion,the integration into established screening programs as a replacement for barium enema in the case of incomplete colonoscopy.The potential role is the use of CTC as a first-line screening method together with Fecal Occult Blood Test,sigmoidoscopy and colonoscopy.However,despite the fact that CTC has been officially endorsed for CRC scre...

  12. Optimizing bowel preparation for multidetector row CT colonography: Effect of Citramag and Picolax

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.A.; Halligan, S. E-mail: s.halligan@ic.ac.uk; Goh, V.; Morley, S.; Atkin, W.; Bartram, C.I

    2003-09-01

    AIM: To compare the adequacy and acceptability of Picolax and Citramag bowel cleansing agents for CT colonography. MATERIALS AND METHODS: Multidetector row CT colonography was performed in 124 subjects; 43 had been prepared with Picolax and 81 with Citramag. Datasets were assessed for retained fluid and solid residue, and overall adequacy of segmental visualization. Preparation acceptability was also assessed. RESULTS: There was significantly less retained fluid with Picolax. The odds of being in the next higher category for retained fluid when using Picolax were 0.33 (CI: 0.22-0.50, p<0.0001) when compared with Citramag, for all segments combined. However there was significantly more retained solid residue with Picolax. The odds of being in the next higher category for retained residue when using Picolax were 2.44 (CI: 1.41-4.24, p=0.002) when compared with Citramag, for all segments combined. There was no significant difference with respect to overall segmental visualization: the odds of a segment being adequately visualized when using Picolax were 1.52 (CI: 0.88-2.65, p=0.14) when compared with Citramag. There was no significant difference with respect to acceptability. CONCLUSION: Picolax results in a significantly drier colon than Citramag and associated with more retained residue. We found Picolax the more suitable preparation for CT colonography.

  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

    2017-07-05

    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. Current status of MR colonography.

    LENUS (Irish Health Repository)

    Thornton, Eavan

    2010-01-01

    The search for an acceptable colorectal cancer screening examination has led to the development of virtual colonoscopy, which includes both computed tomographic (CT) colonography and magnetic resonance (MR) colonography. As indicated by the much larger number of published studies on CT colonography than on MR colonography, multidetector CT appears to be more suitable for colorectal screening than does MR colonography, in part reflecting the ease and speed of performing CT, as well as the increased spatial resolution, decreased cost, and wider availability of CT colonography. The main advantage of MR colonography over CT colonography is that it does not use ionizing radiation, which has important implications for colorectal cancer screening. The use of dark-lumen MR colonography to screen patients for colorectal cancer as well as other abdominopelvic disease could make it more attractive than CT. With the integration of 3.0-T MR colonography, fecal tagging, and parallel imaging into research and clinical settings, new MR colonography protocols must be optimized. Future MR colonography research should address issues such as image characteristics, presence of artifacts, management of specific absorption rate, and hardware-related modifications.

  15. Colon distension and scan protocol for CT-colonography: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Boellaard, Thierry N., E-mail: t.n.boellaard@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Haan, Margriet C. de, E-mail: m.c.dehaan@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Venema, Henk W., E-mail: h.w.venema@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Stoker, Jaap, E-mail: j.stoker@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands)

    2013-08-15

    This article reviews two important aspects of CT-colonography, namely colonic distension and scan parameters. Adequate distension should be obtained to visualize the complete colonic lumen and optimal scan parameters should be used to prevent unnecessary radiation burden. For optimal distension, automatic carbon dioxide insufflation should be performed, preferably via a thin, flexible catheter. Hyoscine butylbromide is – when available – the preferred spasmolytic agent because of the positive effect on insufflation and pain/burden and its low costs. Scans in two positions are required for adequate distension and high polyp sensitivity and decubitus position may be used as an alternative for patients unable to lie in prone position. The great intrinsic contrast between air or tagging and polyps allows the use of low radiation dose. Low-dose protocol without intravenous contrast should be used when extracolonic findings are deemed unimportant. In patients suspected for colorectal cancer, normal abdominal CT scan protocols and intravenous contrast should be used in supine position for the evaluation of extracolonic findings. Dose reduction can be obtained by lowering the tube current and/or voltage. Tube current modulation reduces the radiation dose (except in obese patients), and should be used when available. Iterative reconstructions is a promising dose reducing tool and dual-energy CT is currently evaluated for its applications in CT-colonography. This review also provides our institution's insufflation procedure and scan parameters.

  16. Automated mass detection in contrast-enhanced CT colonography: an approach based on contrast and volume

    Energy Technology Data Exchange (ETDEWEB)

    Luboldt, W. [University Hospital Essen, Clinic and Policlinic of Angiology, Essen (Germany); Multiorgan Screening Foundation (Germany); Tryon, C. [Philips Medical Systems, Best (Netherlands); Kroll, M.; Vogl, T.J. [University Hospital Frankfurt, Department of Radiology, Frankfurt (Germany); Toussaint, T.L. [Multiorgan Screening Foundation (Germany); Holzer, K. [University Hospital Frankfurt, Department of Visceral and Vascular Surgery, Frankfurt (Germany); Hoepffner, N. [University Hospital Frankfurt, Department of Gastroenterology, Frankfurt (Germany)

    2005-02-01

    The purpose of this feasibility study was to design and test an algorithm for automating mass detection in contrast-enhanced CT colonography (CTC). Five patients with known colorectal masses underwent a pre-surgical contrast-enhanced (120 ml volume 1.6 g iodine/s injection rate, 60 s scan delay) CTC in high spatial resolution (16-slice CT: collimation: 16 x 0.75 mm, tablefeed: 24 mm/0.5 s, reconstruction increment: 0.5 mm). A CT-density- and volume-based algorithm searched for masses in the colonic wall, which was extracted before by segmenting and dilating the colonic air lumen and subtracting the inner air. A radiologist analyzed the detections and causes of false positives. All masses were detected, and false positives were easy to identify. Combining CT density with volume as a cut-off is a promising approach for automating mass detection that should be further refined and also tested in contrast-enhanced MR colonography. (orig.)

  17. Evaluation of a radiographer tele-training programme in the interpretation of CT Colonography

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Ammitzbøl; Lefere, Philippe

    2012-01-01

    Colorectal cancer is one of the most common, and deadly human cancers. By early identifi cation of suspect lesions, screening has the potential to reduce mortality. Colonos- copy remains the screening gold standard, but “virtual colonoscopy“ or CT-colonography (CTC) has been shown to generate enc...... unacceptable increases in radiologists’ work-load. This paper describes a tele-radiology-based CTC teaching program designed to alleviate radiology work-load and summarizes the results of a practical evaluation of such trai- ning programs....

  18. Business plan to establish a CT colonography service.

    Science.gov (United States)

    Fajardo, Laurie L; Hurley, James P; Brown, Bruce P; Summers, Robert W; McDaniel, R Donald

    2006-03-01

    The authors describe the University of Iowa Department of Radiology's business planning process to initiate a new service in computed tomographic colonography (CTC). Also known as virtual colonoscopy, CTC is a noninvasive technology that offers less risk, and potentially similar sensitivity and specificity, than conventional optical colonoscopy (OC). Although not currently covered by all insurance payers, about a year ago, the Centers for Medicare and Medicaid Services instituted temporary Current Procedural Terminology codes (Category III) for CTC. In locales where the procedure is not covered by insurers, it is likely to be sought by patients willing to pay out of pocket to undergo noninvasive cancer screening as an alternative to OC. Thus, CTC could become the preferred method of colon cancer surveillance by insurance providers in the near future. In developing the business plan, the authors reviewed pertinent scientific and clinical data to evaluate the need for and efficacy of CTC. Local market data were used to estimate patient and procedure volumes and utilization. The authors modeled financial expectations with respect to return on investment on the basis of recently reported models specific to CTC, resource requirements, and the operational impact of the new service on existing hospital and departmental clinical functions. Because there are few local providers of CTC in the authors' region, the business plan also included a publicity campaign and plan to market the new service, stimulate general public interest early, and differentiate the program as a leader in applying this unique new technology to promote cancer screening. Finally, the planning committee acknowledged and accommodated needs specific to the missions of an academic medical center with respect to research and education in designing the new service.

  19. Colon distension, perceived burden and side-effects of CT-colonography for screening using hyoscine butylbromide or glucagon hydrochloride as bowel relaxant

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Margriet C. de, E-mail: margrietcdehaan@gmail.com [Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Boellaard, Thierry N., E-mail: t.n.boellaard@amc.uva.nl [Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Bossuyt, Patrick M., E-mail: p.m.bossuyt@amc.uva.nl [Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Stoker, Jaap, E-mail: j.stoker@amc.uva.nl [Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands)

    2012-08-15

    Objective: Compare colonic distension and perceived burden of CT-colonography between participants receiving hyoscine butylbromide (buscopan) and glucagon hydrochloride as bowel relaxant. Materials and methods: Data were collected within a screening trial. Participants received 20 mg buscopan intravenously or 1 mg of glucagon intravenously (if buscopan contra-indicated). Colon distension per segment was assessed using a 4-point scale (prone and supine). Data on perceived burden of CT-colonography were collected using a questionnaire two weeks after the examination. Outcome measures between groups were compared using propensity score matching. We used a stratified Wilcoxon-Mann-Whitney test statistic for quantitative and Cochran-Mantel-Haenszel statistics for categorical variables. Results: 541 participants were included: 336 (62%) received buscopan and 205 received glucagon. All buscopan recipients had an adequately distended colon, compared to 96% in the glucagon group (RR 7.31, 95% CI: 1.61-33.28). More glucagon recipients scored the insufflation as rather or extremely burdensome (25% vs. 16%; overall mean score 2.7 vs. 2.4; p < 0.001) and more found the entire CT-colonography rather or extremely burdensome (14% vs. 7%; 2.2 vs. 1.9; p = 0.001). Most frequently reported side effects were a dry mouth in the buscopan group (15%) and nausea in the glucagon group (13%). Conclusion: Compared to glucagon, premedication with buscopan results in significantly more adequately distended colons and a less burdensome procedure. When buscopan can be used, it is the preferred bowel relaxant.

  20. Primary Gallbladder Lymphoma in a Male Patient with No Risk Factors Detected Incidentally by CT Colonography

    Science.gov (United States)

    Karia, Monil; Mitsopoulos, Grigorios; Patel, Ketan; Rafique, Akkib; Sheth, Hemant

    2015-01-01

    Primary gallbladder lymphoma, although rare, usually presents in females with symptoms mimicking cholecystitis. We present a rare case of primary gallbladder in an 81-year-old male with no risk factors whose only symptom was weight loss. Routine blood tests including liver function tests were unremarkable. A CT colonography was carried out to exclude colonic malignancy. Unilateral gallbladder wall thickening and lymphadenopathy were incidentally detected and confirmed by ultrasound and a decision for the patient to undergo laparoscopic cholecystectomy and intraoperative cholangiogram was made. Histology confirmed extranodal marginal zone lymphoma with follow-up staging and biopsy of the bone marrow not demonstrating spread. Cholecystectomy was therefore deemed curative and no adjuvant therapy was necessary. Thickening of the gallbladder wall on any imaging with or without symptoms should not be ignored or assumed to be cholecystitis, even in males with no risk factors. In these patients urgent cholecystectomy with intraoperative cholangiogram is indicated with histology and haematology follow-up. PMID:26587306

  1. Exploration of Analysis Methods for Diagnostic Imaging Tests: Problems with ROC AUC and Confidence Scores in CT Colonography.

    OpenAIRE

    Susan Mallett; Steve Halligan; Gary S Collins; Altman, Doug G.

    2014-01-01

    BACKGROUND: Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. METHODS: In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using ...

  2. PET/CT colonography: a novel non-invasive technique for assessment of extent and activity of ulcerative colitis

    Energy Technology Data Exchange (ETDEWEB)

    Das, Chandan J.; Sharma, Raju [All India Institute of Medical Sciences, Department of Radiodiagnosis, New Delhi (India); Makharia, Govind K.; Tiwari, Rajeew P. [All India Institute of Medical Sciences, Department of Gastroenterology and Human Nutrition, New Delhi (India); Kumar, Rakesh; Kumar, Rajender; Malhotra, Arun [All India Institute of Medical Sciences, Department of Nuclear Medicine, New Delhi (India)

    2010-04-15

    Extent of involvement and activity of ulcerative colitis (UC) is best evaluated by colonoscopy. Colonoscopy however carries risk during acute exacerbation. We investigated the utility of PET/CT colonography for assessment of extent and activity of UC. Within a 1-week window, 15 patients with mild to moderately active UC underwent colonoscopy and PET/CT colonography 60 min after injection of 10 mCi of {sup 18}F-fluorodeoxyglucose (FDG). PET activity score based on the amount of FDG uptake and endoscopic mucosal activity in seven colonic segments of each patient was recorded. The mean maximum standardized uptake value (SUV{sub max}) of seven segments was compared with activity in liver. A PET activity grade of 0, 1, 2 or 3 was assigned to each region depending upon their SUV{sub max} ratio (colon segment to liver). The extent of disease was left-sided colitis in five and pancolitis in ten. The mean Ulcerative Colitis Disease Activity Index (UCDAI) was 7.6. The number of segments involved as per colonoscopic evaluation and PET/CT colonography was 67 and 66, respectively. There was a good correlation for extent evaluation between the two modalities (kappa 55.3%, p = 0.02). One patient had grade 0 PET activity, nine had grade 2 and five had grade 3 PET activity. In six patients, there was one to one correlation between PET activity grades with that of endoscopic grade. One patient showed activity in the sacroiliac joint suggesting active sacroiliitis. PET/CT colonography is a novel non-invasive technique for the assessment of extent and activity of the disease in patients with UC. (orig.)

  3. Use of multidetector-row CT colonography for detection of colorectal neoplasia in patients referred via the Department of Health '2-week-wait' initiative

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.A.; Halligan, S. E-mail: s.halligan@ic.ac.uk; Saunders, B.P.; Morley, S.; Riesewyk, C.; Atkin, W.; Bartram, C.I

    2003-11-01

    AIM: Patients referred under the Department of Health 2-week wait initiative with symptoms of colorectal cancer frequently undergo whole-colon examination. We investigated the use of computed tomography (CT) colonography as an alternative to colonoscopy in this scenario. MATERIALS AND METHODS: Fifty-four consecutive patients, referred via the 2-week wait initiative and scheduled for colonoscopy, consented to undergo multidetector CT colonography immediately before endoscopy. The site and morphology of any polyp or cancer detected by CT was noted and comparison made with subsequent colonoscopy. RESULTS: Colonoscopy detected polyps or cancer in 29 patients (53.7%). CT colonography prospectively detected 18 of 41 (44%) polyps of 1-5 mm, three of four (75%) polyps of 6-9 mm, four of four (100%) polyps 10 mm or larger, and five of six (83%) cancers. The missed cancer occurred early in the series and was a perceptive error. The overall sensitivity, specificity, positive predictive value and negative predictive value of CT colonography for cancer and polyps 10 mm or greater on a per patient basis were 90, 100, 100 and 98%, respectively. CT detected one renal cancer and one colonic cancer, initially missed due to incomplete colonoscopy. CONCLUSION: CT colonography is a robust technique for investigation of symptomatic patients. The learning curve must be overcome for optimal performance.

  4. Burden of waiting for surveillance CT colonography in patients with screen-detected 6-9 mm polyps

    Energy Technology Data Exchange (ETDEWEB)

    Tutein Nolthenius, Charlotte J. [University of Amsterdam, Department of Radiology, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Boellaard, Thierry N.; Nio, C.Y.; Bipat, Shandra; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands); Haan, Margriet C. de [Meander Medical Center, Department of Radiology, Amersfoort (Netherlands); Thomeer, Maarten G.J. [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Montauban van Swijndregt, Alexander D. [Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Essink-Bot, Marie-Louise [University of Amsterdam, Public Health, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands); Kuipers, Ernst J. [Erasmus University Medical Center, Gastroenterology and Hepatology, Rotterdam (Netherlands); Erasmus University Medical Center, Internal medicine, Rotterdam (Netherlands); Dekker, Evelien [University of Amsterdam, Gastroenterology and Hepatology, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands)

    2016-11-15

    We assessed the burden of waiting for surveillance CT colonography (CTC) performed in patients having 6-9 mm colorectal polyps on primary screening CTC. Additionally, we compared the burden of primary and surveillance CTC. In an invitational population-based CTC screening trial, 101 persons were diagnosed with <3 polyps 6-9 mm, for which surveillance CTC after 3 years was advised. Validated questionnaires regarding expected and perceived burden (5-point Likert scales) were completed before and after index and surveillance CTC, also including items on burden of waiting for surveillance CTC. McNemar's test was used for comparison after dichotomization. Seventy-eight (77 %) of 101 invitees underwent surveillance CTC, of which 66 (85 %) completed the expected and 62 (79 %) the perceived burden questionnaire. The majority of participants (73 %) reported the experience of waiting for surveillance CTC as 'never' or 'only sometimes' burdensome. There was almost no difference in expected and perceived burden between surveillance and index CTC. Waiting for the results after the procedure was significantly more burdensome for surveillance CTC than for index CTC (23 vs. 8 %; p = 0.012). Waiting for surveillance CTC after primary CTC screening caused little or no burden for surveillance participants. In general, the burden of surveillance and index CTC were comparable. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-15

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

  6. CT colonography for synchronous colorectal lesions in patients with colorectal cancer: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    McArthur, D.R.; Karandikar, S.S. [Heart of England NHS Foundation Trust (Teaching), Department of Surgery, Birmingham (United Kingdom); Mehrzad, H.; Patel, R.; Dadds, J.; Pallan, A.; Roy-Choudhury, S. [Heart of England NHS Foundation Trust (Teaching), Department of Radiology, Birmingham (United Kingdom)

    2010-03-15

    To assess accuracy of CT colonography (CTC) in identifying synchronous lesions in patients with colorectal carcinoma. This study included 174 consecutive patients undergoing CTC as part of staging or primary investigation where a colorectal cancer was diagnosed between 2004 and 2007. Prone unenhanced and portal phase enhanced supine series with air or CO{sub 2} distension were acquired using 4- or 16-slice CT (Toshiba) and read by 2D {+-} 3D formats. Synchronous lesions were classified according to American College of Radiology's (ACR) polyp classification. Segmental gold standard was flexible sigmoidoscopy/colonoscopy within 1 year and/or histology of colonic resection supplemented by follow-up. Nine patients without gold standard were excluded. Sensitivity, specificity and accuracy were calculated on a per polyp, per patient and per segment basis and discrepancies analysed. Direct comparable data were available for 764/990 colonic segments from 165 patients. Of 41 (C2-C4) synchronous lesions on ''gold standard'', 33 were correctly identified on virtual colonoscopy (VC), overall per polyp sensitivity was 80.5%, with detection rates of 20/24 C3 (83.3%) and 3/3 C4 (100%) with per patient and per segment specificity of 95.4% and 99.2%, respectively. CTC is an accurate technique to assess for significant synchronous lesions in patients with colorectal cancer and is applicable for total pre-operative colonic visualisation. (orig.)

  7. Comparison of a 4-Day versus 2-Day Low Fiber Diet Regimen in Barium Tagging CT Colonography in Incomplete Colonoscopy Patients

    Directory of Open Access Journals (Sweden)

    Kaan Meric

    2015-01-01

    Full Text Available Our aim was to compare the amount of residual feces, residual fluid, the tagging quality, and patient compliance using 4-day versus 2-day low fiber diet regimen in barium tagging CT colonography in incomplete colonoscopy patients. Methods. A total of 101 patients who underwent CT colonography were assigned to 2-day diet group (n=56 and 4-day diet group (n=45. Fecal tagging was achieved with barium sulphate while bisacodyl and sennoside B were used for bowel preparation. Residual solid stool was divided into two groups measuring 0.05. The prevalence of moderate discomfort was significantly higher in 4-day group (P<0.001. Conclusion. Our study shows that 2-day limited bowel preparation regimen for fecal tag CT colonography is a safe and reasonable technique to evaluate the entire colon, particularly in incomplete conventional colonoscopy patients.

  8. Primary Gallbladder Lymphoma in a Male Patient with No Risk Factors Detected Incidentally by CT Colonography

    Directory of Open Access Journals (Sweden)

    Monil Karia

    2015-01-01

    Full Text Available Primary gallbladder lymphoma, although rare, usually presents in females with symptoms mimicking cholecystitis. We present a rare case of primary gallbladder in an 81-year-old male with no risk factors whose only symptom was weight loss. Routine blood tests including liver function tests were unremarkable. A CT colonography was carried out to exclude colonic malignancy. Unilateral gallbladder wall thickening and lymphadenopathy were incidentally detected and confirmed by ultrasound and a decision for the patient to undergo laparoscopic cholecystectomy and intraoperative cholangiogram was made. Histology confirmed extranodal marginal zone lymphoma with follow-up staging and biopsy of the bone marrow not demonstrating spread. Cholecystectomy was therefore deemed curative and no adjuvant therapy was necessary. Thickening of the gallbladder wall on any imaging with or without symptoms should not be ignored or assumed to be cholecystitis, even in males with no risk factors. In these patients urgent cholecystectomy with intraoperative cholangiogram is indicated with histology and haematology follow-up.

  9. CT colonography with reduced bowel preparation after incomplete colonoscopy in the elderly

    Energy Technology Data Exchange (ETDEWEB)

    Iafrate, F.; Stagnitti, A. [University of Rome, Department of Radiological Sciences, Rome (Italy); Hassan, C.; Zullo, A. [Hospital-Rome, Gastroenterology and Digestive Endoscopy Unit, Rome (Italy); Spagnuolo, A. [Univeristy of Rome, I.C.O.T, Department of Radiological Sciences, Latina (Italy); Ferrari, R.; Laghi, A.

    2008-07-15

    We prospectively assessed the feasibility and acceptance of computerized tomographic colonography (CTC) without bowel cathartic preparation in elderly patients after incomplete colonoscopy. A total of 136 patients underwent CTC without cathartic preparation. The time delay between conventional colonoscopy and CTC ranged between 3 and 20 days, depending on the clinical situation. Before CTC, fecal tagging was achieved by adding diatrizoate meglumine and diatrizoate sodium to regular meals. CTCs were interpreted using a primary two-dimensional (2D) approach and 3D images for further characterization. Patients were interviewed before and 2 weeks after CTC to assess preparation acceptance. CTC was feasible and technically successful in all the 136 patients. Fecal tagging was judged as excellent in 113 (83%) patients and sufficient in 23 (17%). Average CT image interpretation time was 14.8 min. Six (4.4%) cases of colorectal cancer and nine (6.6%) large polyps were detected, as well as 23 (11.3%) extracolonic findings of high clinical importance. No major side effect occurred, although 25% patients reported minor side effects, especially diarrhea. Overall, 76/98 patients replied that they would be willing to repeat the test if necessary. CTC without cathartic preparation is a technically feasible and safe procedure to complete a colonic study in the elderly, prompting its use in clinical practice. (orig.)

  10. Does CT colonography have a role for population-based colorectal cancer screening?

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Margriet C. de; Stoker, Jaap [Academic Medical Centre Amsterdam, Department of Radiology, G1-228, PO Box 22700, Amsterdam (Netherlands); Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom)

    2012-07-15

    Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. CRC screening has been proven to reduce disease-specific mortality and several European countries employ national screening programmes. These almost exclusively rely on stool tests, with endoscopy used as an adjunct in some countries. Computed tomographic colonography (CTC) is a potential screening test, with an estimated sensitivity of 88 % for advanced neoplasia {>=}10 mm. Recent randomised studies have shown that CTC and colonoscopy have similar yields of advanced neoplasia per screened invitee, indicating that CTC is potentially viable as a primary screening test. However, the evidence is not fully elaborated. It is unclear whether CTC screening is cost-effective and the impact of extracolonic findings, both medical and economic, remains unknown. Furthermore, the effect of CTC screening on CRC-related mortality is unknown, as it is also unknown for colonoscopy. It is plausible that both techniques could lead to decreased mortality, as for sigmoidoscopy and gFOBT. Although radiation exposure is a drawback, this disadvantage may be over-emphasised. In conclusion, the detection characteristics and acceptability of CTC suggest it is a viable screening investigation. Implementation will depend on detection of extracolonic disease and health-economic impact. Key Points circle Meta-analysis of CT colonographic screening showed high sensitivity for advanced neoplasia {>=}10mm. (orig.)

  11. Five year colorectal cancer outcomes in a large negative CT colonography screening cohort

    Energy Technology Data Exchange (ETDEWEB)

    Kim, David H.; Pooler, B.D.; Pickhardt, Perry J. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); Weiss, Jennifer M. [University of Wisconsin School of Medicine and Public Health, Section of Gastroenterology, Department of Internal Medicine, Madison, WI (United States)

    2012-07-15

    To assess the 5-year incidence of clinically presenting colorectal cancers following a negative CT colonography (CTC) screening examination, as few patient outcome data regarding a negative CTC screening result exist. Negative CTC screening patients (n = 1,050) in the University of Wisconsin Health system over a 14-month period were included. An electronic medical record (EMR) review was undertaken, encompassing provider, colonoscopy, imaging and histopathology reports. Incident colorectal cancers and other important GI tumours were recorded. Of the 1,050 cohort (mean [{+-}SD] age 56.9 {+-} 7.4 years), 39 (3.7%) patients were excluded owing to lack of follow-up within our system beyond the initial screening CTC. The remaining 1,011 patients were followed for an average of 4.73 {+-} 1.15 years. One incident colorectal adenocarcinoma represented a crude cancer incidence of 0.2 cancers per 1,000 patient years. EMR revealed 14 additional patients with clinically important GI tumours including: advanced adenomas (n = 11), appendiceal goblet cell carcinoid (n = 1), appendiceal mucinous adenoma (n = 1) and metastatic ileocolonic carcinoid (n = 1). All positive patients including the incident carcinoma are alive at the time of review. Clinically presenting colorectal adenocarcinoma is rare in the 5 years following negative screening CTC, suggesting that current strategies, including non-reporting of diminutive lesions, are appropriate. (orig.)

  12. Bowel preparation in CT colonography: electrolyte and renal function disturbances in the frail and elderly patient

    Energy Technology Data Exchange (ETDEWEB)

    Mc Laughlin, Patrick; Mc Sweeney, Sean; Mc Williams, Sebastian; O' Regan, Kevin; Kelly, Denis; Maher, Michael M. [Cork University Hospital, Department of Radiology, Cork (Ireland); Eustace, Joseph; O' Connor, Michael [Cork University Hospital, Department of Medicine, Cork (Ireland)

    2010-03-15

    Elderly patients are at increased risk of biochemical disturbances secondary to cathartic medications. This study investigates the renal function, electrolyte and clinical disturbances associated with CT colonography (CTC) with sodium picosulphate-magnesium citrate (SPS-MC) in a subgroup of frail, elderly patients. Patients aged over 70 years considered at risk of complication during SPS-MC administration by a physician specialised in care of the elderly were included in this retrospective study. Biochemical parameters pre- and post-CTC and the presence of co-morbidities were recorded. Imaging findings and quality of bowel preparation at CTC were graded by consensus by two radiologists. Of the 72 patients 56% had co-morbidities that caution the use of SPS-MC. No significant changes in serum urea, sodium, potassium or estimated glomerular filtration rate (eGFR) occurred post-CTC (p > 0.10). Serum magnesium increased by 0.11 mmol/L in 14 patients (p = 0.03) without clinical sequelae. Good overall preparation was achieved in 88% of patients, allowing confident identification of signs of colonic neoplasia in 20 patients (27%). A mild increase in serum magnesium but no other significant biochemical disturbance was observed. In our group CTC with SPS-MC was safe and effective; however, we advise an alternate preparation be considered in patients with decreased renal function due to decreased magnesium clearance. (orig.)

  13. Prevalence and distribution of colonic diverticula assessed with CT colonography (CTC)

    Energy Technology Data Exchange (ETDEWEB)

    De Cecco, Carlo Nicola [University of Rome ' ' Sapienza' ' - Polo Pontino, Department of Radiological Sciences, Oncology and Pathology, Latina (Italy); Medical University of South Carolina, Department of Radiology and Radiological Sciences, Charleston, SC (United States); Ciolina, Maria; Rengo, Marco; Bellini, Davide; Muscogiuri, Giuseppe; Iafrate, Franco; Laghi, Andrea [University of Rome ' ' Sapienza' ' - Polo Pontino, Department of Radiological Sciences, Oncology and Pathology, Latina (Italy); Annibale, Bruno [University of Rome ' ' Sapienza' ' - Sant' Andrea Hospital, Department of Digestive and Liver Disease, Rome (Italy); Maruotti, Antonello [University ' ' Roma Tre' ' , Department of Public Institutions, Economy and Society, Rome (Italy); University of Southampton, Southampton Statistical Sciences Research Institute and School of Mathematics, Southampton (United Kingdom); Saba, Luca [Azienda Ospedaliera Universitaria di Cagliari, Department of Radiology, Cagliari (Italy)

    2016-03-15

    This study aimed to evaluate the prevalence of colonic diverticula according to age, gender, distribution, disease extension and symptoms with CT colonography (CTC). The study population included 1091 consecutive patients who underwent CTC. Patients with diverticula were retrospectively stratified according to age, gender, clinical symptoms and colonic segment involvement. Extension of colonic diverticula was evaluated using a three-point quantitative scale. Using this data, a multivariate regression analysis was applied to investigate the existence of any correlation among variables. Colonic diverticula were observed in 561 patients (240 men, mean age 68 ± 12 years). Symptomatic uncomplicated diverticular disease (SUDD) was present in 47.4 % of cases. In 25.6 % of patients ≤40 years, at least one diverticulum in the colon was observed. Prevalence of right-sided diverticula in patients >60 years was 14.2 % in caecum and 18.5 % in ascending colon. No significant difference was found between symptomatic and asymptomatic patients regarding diverticula prevalence and extension. No correlation was present between diverticula extension and symptoms. The incidence of colonic diverticula appears to be greater than expected. Right colon diverticula do not appear to be an uncommon finding, with their prevalence increasing with patient age. SUDD does not seem to be related to diverticula distribution and extension. (orig.)

  14. Comparison of the Diagnostic Performance of CT Colonography Interpreted by Radiologists and Radiographers

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Ammitzbøl; Lefere, Philippe

    2013-01-01

    Objective To compare computed tomographic colonography (CTC) performance of 4 trained radiographers with the CTC performance of 2 experienced radiologists. Methods Four radiographers and two radiologists interpreted 87 cases with 40 polyps ≥6 mm. Sensitivity, specificity-, and positive predictive...

  15. Deep multi-spectral ensemble learning for electronic cleansing in dual-energy CT colonography

    Science.gov (United States)

    Tachibana, Rie; Näppi, Janne J.; Hironaka, Toru; Kim, Se Hyung; Yoshida, Hiroyuki

    2017-03-01

    We developed a novel electronic cleansing (EC) method for dual-energy CT colonography (DE-CTC) based on an ensemble deep convolution neural network (DCNN) and multi-spectral multi-slice image patches. In the method, an ensemble DCNN is used to classify each voxel of a DE-CTC image volume into five classes: luminal air, soft tissue, tagged fecal materials, and partial-volume boundaries between air and tagging and those between soft tissue and tagging. Each DCNN acts as a voxel classifier, where an input image patch centered at the voxel is generated as input to the DCNNs. An image patch has three channels that are mapped from a region-of-interest containing the image plane of the voxel and the two adjacent image planes. Six different types of spectral input image datasets were derived using two dual-energy CT images, two virtual monochromatic images, and two material images. An ensemble DCNN was constructed by use of a meta-classifier that combines the output of multiple DCNNs, each of which was trained with a different type of multi-spectral image patches. The electronically cleansed CTC images were calculated by removal of regions classified as other than soft tissue, followed by a colon surface reconstruction. For pilot evaluation, 359 volumes of interest (VOIs) representing sources of subtraction artifacts observed in current EC schemes were sampled from 30 clinical CTC cases. Preliminary results showed that the ensemble DCNN can yield high accuracy in labeling of the VOIs, indicating that deep learning of multi-spectral EC with multi-slice imaging could accurately remove residual fecal materials from CTC images without generating major EC artifacts.

  16. Fecal-tagging CT colonography with structure-analysis electronic cleansing for detection of colorectal flat lesions

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonghua, E-mail: howardyonghua@gmail.com [Department of Radiology, Xuhui Central Hospital of Shanghai and China Academy of Sciences Shanghai Medical Center, 966 Huai Hai Central Road, Shanghai 200031 (China); Department of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016 (China); Cai, Wenli; Nappi, Janne; Yoshida, Hiro [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 25 New Chardon Street 400C, Boston, MA 02114 (United States)

    2012-08-15

    Purpose: To evaluate the feasibility and sensitivity of the 3D-reading of fecal-tagging CT colonography (CTC) with a novel structure-analysis electronic cleansing (SAEC) in detecting colorectal flat lesions in comparison with a cleansed 3D reading with Viatronix V3D Colon system (V3D) and primary uncleansed 2D reading (2D). Materials and methods: Forty CTC cases with flat lesions were retrospectively observed. The Subjects from a multicenter clinical trial underwent cathartic bowel preparation with orally administrated barium-based fecal-tagging. Sixty-nine flat lesions were confirmed using colonoscopy and histopathology as a reference standard. The results from SAEC reading were compared with those of prospective V3D and 2D readings. Results: Overall detection sensitivity with SAEC was 52% (36/69), which was statistically higher than that of 32% (22/69) and 29% (20/69) with V3D and 2D readings, respectively (p < 0.05). The sensitivities in detecting not-on-fold flat lesions were 63% (24/38), 45% (17/38), and 42% (16/38) with SAEC, V3D, and 2D readings, respectively; whereas those of on-fold flat lesions were 39% (12/31), 16% (5/31), and 13% (4/31), respectively. None of the eight flat lesions (2-9 mm) at cecum was detected by any of the three reading methods. Excluding the flat lesions at cecum, the sensitivity with SAEC for detecting flat lesion {>=}4 mm increased to 84% (31/37). Conclusions: The fecal-tagging CTC with structure-analysis electronic cleansing could yield a high sensitivity for detecting flat lesions {>=}4 mm. The not-on-fold flat lesions were detected with higher sensitivity than on-fold flat lesions.

  17. Deep learning for electronic cleansing in dual-energy CT colonography

    Science.gov (United States)

    Tachibana, Rie; Näppi, Janne J.; Hironakaa, Toru; Kim, Se Hyung; Yoshida, Hiroyuki

    2016-03-01

    The purpose of this study was to develop a novel deep-learning-based electronic cleansing (EC) method for dual-energy CT colonography (DE-CTC). In this method, an ensemble of deep convolutional neural networks (DCNNs) is used to classify each voxel of DE-CTC image volumes into one of five multi-material (MUMA) classes: luminal air, soft tissue, tagged fecal material, or a partial-volume boundary between air and tagging or that of soft tissue and tagging. Each DCNN acts as a voxel classifier. At each voxel, a region-of-interest (ROI) centered at the voxel is extracted. After mapping the pixels of the ROI to the input layer of a DCNN, a series of convolutional and max-pooling layers is used to extract features with increasing levels of abstraction. The output layer produces the probabilities at which the input voxel belongs to each of the five MUMA classes. To develop an ensemble of DCNNs, we trained multiple DCNNs based on multi-spectral image volumes derived from the DE-CTC images, including material decomposition images and virtual monochromatic images. The outputs of these DCNNs were then combined by means of a meta-classifier for precise classification of the voxels. Finally, the electronically cleansed CTC images were generated by removing regions that were classified as other than soft tissue, followed by colon surface reconstruction. Preliminary results based on 184,320 images sampled from 30 clinical CTC cases showed a higher accuracy in labeling these classes than that of our previous machine-learning methods, indicating that deep-learning-based multi-spectral EC can accurately remove residual fecal materials from CTC images without generating major EC artifacts.

  18. Strategies for improved interpretation of computer-aided detections for CT colonography utilizing distributed human intelligence.

    Science.gov (United States)

    McKenna, Matthew T; Wang, Shijun; Nguyen, Tan B; Burns, Joseph E; Petrick, Nicholas; Summers, Ronald M

    2012-08-01

    Computer-aided detection (CAD) systems have been shown to improve the diagnostic performance of CT colonography (CTC) in the detection of premalignant colorectal polyps. Despite the improvement, the overall system is not optimal. CAD annotations on true lesions are incorrectly dismissed, and false positives are misinterpreted as true polyps. Here, we conduct an observer performance study utilizing distributed human intelligence in the form of anonymous knowledge workers (KWs) to investigate human performance in classifying polyp candidates under different presentation strategies. We evaluated 600 polyp candidates from 50 patients, each case having at least one polyp ≥6 mm, from a large database of CTC studies. Each polyp candidate was labeled independently as a true or false polyp by 20 KWs and an expert radiologist. We asked each labeler to determine whether the candidate was a true polyp after looking at a single 3D-rendered image of the candidate and after watching a video fly-around of the candidate. We found that distributed human intelligence improved significantly when presented with the additional information in the video fly-around. We noted that performance degraded with increasing interpretation time and increasing difficulty, but distributed human intelligence performed better than our CAD classifier for "easy" and "moderate" polyp candidates. Further, we observed numerous parallels between the expert radiologist and the KWs. Both showed similar improvement in classification moving from single-image to video interpretation. Additionally, difficulty estimates obtained from the KWs using an expectation maximization algorithm correlated well with the difficulty rating assigned by the expert radiologist. Our results suggest that distributed human intelligence is a powerful tool that will aid in the development of CAD for CTC. Copyright © 2012. Published by Elsevier B.V.

  19. Deep learning of contrast-coated serrated polyps for computer-aided detection in CT colonography

    Science.gov (United States)

    Näppi, Janne J.; Pickhardt, Perry; Kim, David H.; Hironaka, Toru; Yoshida, Hiroyuki

    2017-03-01

    Serrated polyps were previously believed to be benign lesions with no cancer potential. However, recent studies have revealed a novel molecular pathway where also serrated polyps can develop into colorectal cancer. CT colonography (CTC) can detect serrated polyps using the radiomic biomarker of contrast coating, but this requires expertise from the reader and current computer-aided detection (CADe) systems have not been designed to detect the contrast coating. The purpose of this study was to develop a novel CADe method that makes use of deep learning to detect serrated polyps based on their contrast-coating biomarker in CTC. In the method, volumetric shape-based features are used to detect polyp sites over soft-tissue and fecal-tagging surfaces of the colon. The detected sites are imaged using multi-angular 2D image patches. A deep convolutional neural network (DCNN) is used to review the image patches for the presence of polyps. The DCNN-based polyp-likelihood estimates are merged into an aggregate likelihood index where highest values indicate the presence of a polyp. For pilot evaluation, the proposed DCNN-CADe method was evaluated with a 10-fold cross-validation scheme using 101 colonoscopy-confirmed cases with 144 biopsy-confirmed serrated polyps from a CTC screening program, where the patients had been prepared for CTC with saline laxative and fecal tagging by barium and iodine-based diatrizoate. The average per-polyp sensitivity for serrated polyps >=6 mm in size was 93+/-7% at 0:8+/-1:8 false positives per patient on average. The detection accuracy was substantially higher that of a conventional CADe system. Our results indicate that serrated polyps can be detected automatically at high accuracy in CTC.

  20. Screening CT Colonography: Multicenter Survey of Patient Experience, Preference, and Potential Impact on Adherence

    Science.gov (United States)

    Pooler, B. Dustin; Baumel, Mark J.; Cash, Brooks D.; Moawad, Fouad J.; Riddle, Mark S.; Patrick, Amy M.; Damiano, Mark; Lee, Matthew H.; Kim, David H.; del Rio, Alejandro Muñoz; Pickhardt, Perry J.

    2013-01-01

    OBJECTIVE Prior research indicates CT colonography (CTC) would be a cost-effective colorectal cancer (CRC) screening test if widespread availability were to increase overall CRC screening adherence rates. The primary aims of this multicenter study were to evaluate patient experience and satisfaction with CTC screening and compare preference against screening colonoscopy. MATERIALS AND METHODS A 12-question survey instrument measuring pretest choice, experience, and satisfaction was given to a consecutive cohort of adults undergoing CTC screening in three disparate screening settings: university academic center, military medical center, and community practice. The study cohort was composed of individuals voluntarily participating in clinical CTC screening programs. RESULTS A total of 1417 patients responded to the survey. The top reasons for choosing CTC for screening included “noninvasiveness” (68.0%), “avoidance of sedation/anesthesia” (63.1%), “ability to drive after the test” (49.2%), “avoidance of optical colonoscopy risks” (46.9%), and “identifying abnormalities outside the colon” (43.3%). Only 7.2% of patients reported pain during the CTC examination and only 2.5% reported greater than moderate discomfort. Of 441 patients who had experienced both CTC and optical colonoscopy, 77.1% preferred CTC and 13.8% preferred optical colonoscopy. Of all patients, 29.6% indicated that they may not have undergone optical colonoscopy screening if CTC were not available. Of all patients, 92.9% labeled their overall experience with CTC as “excellent” or “good,” and 93.0% indicated they would choose CTC for their next screening. CONCLUSION Respondents reported a very high satisfaction level with CTC, and those who had experienced both modalities indicated a preference for CTC over optical colonoscopy. These results suggest that CTC has the potential to increase adherence to CRC screening guidelines if widely available. PMID:22623549

  1. Use of CT colonography in the English Bowel Cancer Screening Programme

    Science.gov (United States)

    Plumb, Andrew A; Halligan, Steve; Nickerson, Claire; Bassett, Paul; Goddard, Andrew F; Taylor, Stuart A; Patnick, Julietta; Burling, David

    2014-01-01

    Objective To examine use of CT colonography (CTC) in the English Bowel Cancer Screening Programme (BCSP) and investigate detection rates. Design Retrospective analysis of routinely coded BCSP data. Guaiac faecal occult blood test (gFOBt)-positive screenees undergoing CTC from June 2006 to July 2012 as their first-line colonic investigation were included. Abnormalities found at CTC, subsequent polyp, adenoma and cancer detection and positive predictive value (PPV) were calculated. Detection rates were compared with those observed in gFOBt-positive screenees investigated by colonoscopy. Multilevel logistic regression was used to examine factors associated with variable detection. Results 2731 screenees underwent CTC. Colorectal cancer (CRC) or polyps were suspected in 1027 individuals (37.6%; 95% CI 33.8% to 41.4%); 911 of these underwent confirmatory testing. 124 screenees had CRC (4.5%) and 533 had polyps (19.5%), 468 adenomatous (17.1%). Overall detection was 24.1% (95% CI 21.5% to 26.6%) for CRC or polyps and 21.7% (95% CI 19.2% to 24.1%) for CRC or adenoma. Advanced neoplasia was detected in 504 screenees (18.5%; 95% CI 16.1% to 20.8%). PPV for CRC or polyp was 72.1% (95% CI 66.6% to 77.6%). By comparison, 9.0% of 72 817 screenees undergoing colonoscopy had cancer and 50.6% had polyps; advanced neoplasia was detected in 32.7%. CTC detection rates and PPV were higher at centres with experienced radiologists (>1000 examinations) and at high-volume centres (>175 cases/radiologist/annum). Centres using three-dimensional interpretation detected more neoplasia. Conclusions In the BCSP, detection rates after positive gFOBt are lower for CTC than colonoscopy, although populations undergoing the two tests are different. Centres with more experienced radiologists have higher detection and accuracy. Rigorous quality assurance of BCSP radiology is needed. PMID:23955527

  2. Frequency analysis of gaze points with CT colonography interpretation using eye gaze tracking system

    Science.gov (United States)

    Tsutsumi, Shoko; Tamashiro, Wataru; Sato, Mitsuru; Okajima, Mika; Ogura, Toshihiro; Doi, Kunio

    2017-03-01

    It is important to investigate eye tracking gaze points of experts, in order to assist trainees in understanding of image interpretation process. We investigated gaze points of CT colonography (CTC) interpretation process, and analyzed the difference in gaze points between experts and trainees. In this study, we attempted to understand how trainees can be improved to a level achieved by experts in viewing of CTC. We used an eye gaze point sensing system, Gazefineder (JVCKENWOOD Corporation, Tokyo, Japan), which can detect pupil point and corneal reflection point by the dark pupil eye tracking. This system can provide gaze points images and excel file data. The subjects are radiological technologists who are experienced, and inexperienced in reading CTC. We performed observer studies in reading virtual pathology images and examined observer's image interpretation process using gaze points data. Furthermore, we examined eye tracking frequency analysis by using the Fast Fourier Transform (FFT). We were able to understand the difference in gaze points between experts and trainees by use of the frequency analysis. The result of the trainee had a large amount of both high-frequency components and low-frequency components. In contrast, both components by the expert were relatively low. Regarding the amount of eye movement in every 0.02 second we found that the expert tended to interpret images slowly and calmly. On the other hand, the trainee was moving eyes quickly and also looking for wide areas. We can assess the difference in the gaze points on CTC between experts and trainees by use of the eye gaze point sensing system and based on the frequency analysis. The potential improvements in CTC interpretation for trainees can be evaluated by using gaze points data.

  3. Deep transfer learning of virtual endoluminal views for the detection of polyps in CT colonography

    Science.gov (United States)

    Näppi, Janne J.; Hironaka, Toru; Regge, Daniele; Yoshida, Hiroyuki

    2016-03-01

    Proper training of deep convolutional neural networks (DCNNs) requires large annotated image databases that are currently not available in CT colonography (CTC). In this study, we employed a deep transfer learning (DETALE) scheme to circumvent this problem in automated polyp detection for CTC. In our method, a DCNN that had been pre-trained with millions of non-medical images was adapted to identify polyps using virtual endoluminal images of the polyp candidates prompted by a computer-aided detection (CADe) system. For evaluation, 154 CTC cases with and without fecal tagging were divided randomly into a development set and an external validation set including 107 polyps >=6 mm in size. A CADe system was trained to detect polyp candidates using the development set, and the virtual endoluminal images of the polyp candidates were labeled manually into true-positive and several false-positive (FP) categories for transfer learning of the DCNN. Next, the trained CADe system was used to detect polyp candidates from the external validation set, and the DCNN reviewed their images to determine the final detections. The detection sensitivity of the standalone CADe system was 93% at 6.4 FPs per patient on average, whereas the DCNN reduced the number of FPs to 2.0 per patient without reducing detection sensitivity. Most of the remaining FP detections were caused by untagged stool. In fecal-tagged CTC cases, the detection sensitivity was 94% at only 0.78 FPs per patient on average. These preliminary results indicate that DETALE can yield substantial improvement in the accuracy of automated polyp detection in CTC.

  4. CT colonography with minimal bowel preparation: evaluation of tagging quality, patient acceptance and diagnostic accuracy in two iodine-based preparation schemes

    Energy Technology Data Exchange (ETDEWEB)

    Liedenbaum, Marjolein H. [Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands); Academic Medical Center, Amsterdam (Netherlands); Vries, A.H. de; Bipat, S.; Stoker, J. [Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands); Gouw, C.I.B.F. [Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands); Gelre Hospitals, Department of Radiology, Apeldoorn (Netherlands); Rijn, A.F. van; Dekker, E. [Academic Medical Centre, Department of Gastroenterology and Hepatology, Amsterdam (Netherlands)

    2010-02-15

    The aim of this study was to compare a 1-day with a 2-day iodine bowel preparation for CT colonography in a positive faecal occult blood test (FOBT) screening population. One hundred consecutive patients underwent CT colonography and colonoscopy with segmental unblinding. The first 50 patients (group 1) ingested 7*50 ml iodinated contrast starting 2 days before CT colonography. The latter 50 patients (group 2) ingested 4*50 ml iodinated contrast starting 1 day before CT colonography. Per colonic segment measurements of residual stool attenuation and homogeneity were performed, and a subjective evaluation of tagging quality (grade 1-5) was done. Independently, two reviewers performed polyp and carcinoma detection. The tagging density was 638 and 618 HU (p = 0.458) and homogeneity 91 and 86 HU for groups 1 and 2, respectively (p = 0.145). The tagging quality was graded 5 (excellent) in 90% of all segments in group 1 and 91% in group 2 (p = 0.749). Mean per-polyp sensitivity for lesions {>=}10 mm was 86% in group 1 and 97% in group 2 (p = 0.355). Patient burden from diarrhoea significantly decreased for patients in group 2. One-day preparation with meglumine ioxithalamate results in an improved patient acceptability compared with 2-day preparation and has a comparable, excellent image quality and good diagnostic performance. (orig.)

  5. Large-scale validation of a computer-aided polyp detection algorithm for CT colonography using cluster computing

    Science.gov (United States)

    Bitter, Ingmar; Brown, John E.; Brickman, Daniel; Summers, Ronald M.

    2004-04-01

    The presented method significantly reduces the time necessary to validate a computed tomographic colonography (CTC) computer aided detection (CAD) algorithm of colonic polyps applied to a large patient database. As the algorithm is being developed on Windows PCs and our target, a Beowulf cluster, is running on Linux PCs, we made the application dual platform compatible using a single source code tree. To maintain, share, and deploy source code, we used CVS (concurrent versions system) software. We built the libraries from their sources for each operating system. Next, we made the CTC CAD algorithm dual-platform compatible and validate that both Windows and Linux produced the same results. Eliminating system dependencies was mostly achieved using the Qt programming library, which encapsulates most of the system dependent functionality in order to present the same interface on either platform. Finally, we wrote scripts to execute the CTC CAD algorithm in parallel. Running hundreds of simultaneous copies of the CTC CAD algorithm on a Beowulf cluster computing network enables execution in less than four hours on our entire collection of over 2400 CT scans, as compared to a month a single PC. As a consequence, our complete patient database can be processed daily, boosting research productivity. Large scale validation of a computer aided polyp detection algorithm for CT colonography using cluster computing significantly improves the round trip time of algorithm improvement and revalidation.

  6. Polyp measurement and size categorisation by CT colonography: effect of observer experience in a multi-centre setting

    Energy Technology Data Exchange (ETDEWEB)

    Burling, David; Bartram, Clive; De Villiers, Melinda; Honeyfield, Lesley [St. Marks Hospital, Intestinal Imaging Centre, London (United Kingdom); Halligan, Steve; Taylor, Stuart [University College Hospital, Specialist Radiology, Level 2 Podium, London (United Kingdom); Altman, Douglas G. [Centre for Medical Statistics, Oxford (United Kingdom); Atkin, Wendy [St Mark' s Hospital, Cancer Research UK, London (United Kingdom); Fenlon, Helen; Foley, Shane; O' Hare, Alan [Mater Misericordiae, Dublin (Ireland); Laghi, Andrea; Iannaccone, Riccardo; Mangiapane, Filipo; Ori, Sante [La Sapienza, Rome (Italy); Stoker, Jaap; Florie, Jasper; Poulus, Martin; Hulst, Victor van der [Amersterdam Medican Centre, Amsterdam (Netherlands); Frost, Roger [Salisbury District Hospital, Salisbury (United Kingdom); Dessey, Guido; Lefere, Philippe; Marrannes, Jesse [Stedelijk Ziekenhuis, Roeselare (Belgium); Gallo, Teresa; Nieddu, Giulia; Regge, Daniele; Signoretta, Saverio [Candiolo Oncologic Hospital, Turin (Italy); Kay, Clive; Lowe, Andrew; Williams-Butt, Jane [Bradford Royal Infirmary, Bradford (United Kingdom); Neri, Emmanuele; Politi, Benedetta; Vagli, Paola [University of Pisa, Pisa (Italy); Nicholson, David; Renaut, Lisa; Rudralingham, Velauthan [Hope Hospital, Salford (United Kingdom)

    2006-08-15

    The extent measurement error on CT colonography influences polyp categorisation according to established management guidelines is studied using twenty-eight observers of varying experience to classify polyps seen at CT colonography as either 'medium' (maximal diameter 6-9 mm) or 'large' (maximal diameter 10 mm or larger). Comparison was then made with the reference diameter obtained in each patient via colonoscopy. The Bland-Altman method was used to assess agreement between observer measurements and colonoscopy, and differences in measurement and categorisation was assessed using Kruskal-Wallis and Chi-squared test statistics respectively. Observer measurements on average underestimated the diameter of polyps when compared to the reference value, by approximately 2-3 mm, irrespective of observer experience. Ninety-five percent limits of agreement were relatively wide for all observer groups, and had sufficient span to encompass different size categories for polyps. There were 167 polyp observations and 135 (81%) were correctly categorised. Of the 32 observations that were miscategorised, 5 (16%) were overestimations and 27 (84%) were underestimations (i.e. large polyps misclassified as medium). Caution should be exercised for polyps whose colonographic diameter is below but close to the 1-cm boundary threshold in order to avoid potential miscategorisation of advanced adenomas. (orig.)

  7. Appearances of screen-detected versus symptomatic colorectal cancers at CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Plumb, Andrew A.; Pathiraja, Fiona; Taylor, Stuart A.; Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); Nickerson, Claire [Fulwood House, Public Health England, Sheffield (United Kingdom); Wooldrage, Katherine; Atkin, Wendy S. [Imperial College London, Department of Surgery and Cancer, London (United Kingdom); Burling, David [St Mark' s Hospital, Intestinal Imaging Centre, Harrow (United Kingdom)

    2016-12-15

    The aim of this study was to compare the morphology, radiological stage, conspicuity, and computer-assisted detection (CAD) characteristics of colorectal cancers (CRC) detected by computed tomographic colonography (CTC) in screening and symptomatic populations. Two radiologists independently analyzed CTC images from 133 patients diagnosed with CRC in (a) two randomized trials of symptomatic patients (35 patients with 36 tumours) and (b) a screening program using fecal occult blood testing (FOBt; 98 patients with 100 tumours), measuring tumour length, volume, morphology, radiological stage, and subjective conspicuity. A commercial CAD package was applied to both datasets. We compared CTC characteristics between screening and symptomatic populations with multivariable regression. Screen-detected CRC were significantly smaller (mean 3.0 vs 4.3 cm, p < 0.001), of lower volume (median 9.1 vs 23.2 cm{sup 3}, p < 0.001) and more frequently polypoid (34/100, 34 % vs. 5/36, 13.9 %, p = 0.02) than symptomatic CRC. They were of earlier stage than symptomatic tumours (OR = 0.17, 95 %CI 0.07-0.41, p < 0.001), and were judged as significantly less conspicuous (mean conspicuity 54.1/100 vs. 72.8/100, p < 0.001). CAD detection was significantly lower for screen-detected (77.4 %; 95 %CI 67.9-84.7 %) than symptomatic CRC (96.9 %; 95 %CI 83.8-99.4 %, p = 0.02). Screen-detected CRC are significantly smaller, more frequently polypoid, subjectively less conspicuous, and less likely to be identified by CAD than those in symptomatic patients. (orig.)

  8. CT attenuation of colorectal polypoid lesions: evaluation of contrast enhancement in CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Oto, Aytekin [Department of Radiology, Hacettepe University School of Medicine, Ankara (Turkey); Department of Radiology, University of Texas Medical Branch at Galveston, 301 University Boulevard, 77555-0709, Galveston, TX (United States); Gelebek, Veli; Oguz, Berna Sayan; Deger, Ahmet; Akhan, Okan; Besim, Aytekin [Department of Radiology, Hacettepe University School of Medicine, Ankara (Turkey); Sivri, Buelent [Department of Gastroenterology, Hacettepe University School of Medicine, Ankara (Turkey)

    2003-07-01

    The aim of this study was to calculate pre- and postcontrast CT attenuation values of benign colorectal polyp and carcinoma lesions detected by virtual colonoscopy, and to investigate whether contrast enhancement of these lesions can be potentially used for differentiation from residual fluid in the colon. Fifteen benign polyps and 21 colorectal carcinoma lesions detected by virtual colonoscopy in 18 patients were included in our study. All of the polyps and carcinoma lesions were confirmed by colonoscopic biopsy. Measurement of CT attenuation values was performed in precontrast (supine) and postcontrast (prone) scans for each polyp and carcinoma. The CT attenuation values of residual fluid in the colon was also measured from the same location before and after intravenous contrast administration. On unenhanced CT scan mean attenuation values of benign polyps and colorectal carcinomas were 32.4 and 42.6 HU, respectively. Following contrast enhancement, mean attenuation value increased to 78.9 HU for polyps and 90.7 HU for carcinomas. Increase in the CT attenuation values of these lesions was significant (p <0.0001). Mean CT attenuation value of residual fluid before and after administration of IV contrast were 14.6 and 13.8 HU, respectively. The difference between CT attenuation value of residual fluid in the colon before and after contrast material was not significant (p =0.29). Colorectal benign polyps and carcinomas demonstrate significant enhancement following contrast administration and use of intravenous contrast material during virtual colonoscopy may help in some cases in differentiating these solid lesions from residual colonic fluid that does not enhance. (orig.)

  9. Computer-Aided Detection of Polyps in CT Colonography Using Logistic Regression

    NARCIS (Netherlands)

    Van Ravesteijn, V.F.; Van Wijk, C.; Vos, F.M.; Truyen, R.; Peters, J.F.; Stoker, J.; Van Vliet, L.J.

    2010-01-01

    We present a computer-aided detection (CAD) system for computed tomography colonography that orders the polyps according to clinical relevance. TheCADsystem consists of two steps: candidate detection and supervised classification. The characteristics of the detection step lead to specific choices fo

  10. CT colonography: effect of computer-aided detection of colonic polyps as a second and concurrent reader for general radiologists with moderate experience in CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Mang, Thomas; Ringel, Helmut; Weber, Michael [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Bogoni, Luca; Anand, Vikram X.; Hermosillo, Gerardo; Raykar, Vikas; Salganicoff, Marcos; Wolf, Matthias [H IM SY US, Siemens Medical Solutions, Malvern, PA (United States); Chandra, Dass [Temple University, Philadelphia, PA (United States); Curtin, Andrew J. [Tristate Imaging Consultants, Abington, PA (United States); Lev-Toaff, Anna S. [University of Pennsylvania, Philadelphia, PA (United States); Noah, Ralph [Diagnostic Imaging Associates, Wilmington, DE (United States); Shaw, Robert [The Chester County Hospital, West Chester, PA (United States); Summerton, Susan [Albert Einstein Medical Center, Philadelphia, PA (United States); Tappouni, Rafel F.R. [Wake Forest University School of Medicine, Winston-Salem, NC (United States); Obuchowski, Nancy A. [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States)

    2014-07-15

    To assess the effectiveness of computer-aided detection (CAD) as a second reader or concurrent reader in helping radiologists who are moderately experienced in computed tomographic colonography (CTC) to detect colorectal polyps. Seventy CTC datasets (34 patients: 66 polyps ≥6 mm; 36 patients: no abnormalities) were retrospectively reviewed by seven radiologists with moderate CTC experience. After primary unassisted evaluation, a CAD second read and, after a time interval of ≥4 weeks, a CAD concurrent read were performed. Areas under the receiver operating characteristic (ROC) curve (AUC), along with per-segment, per-polyp and per-patient sensitivities, and also reading times, were calculated for each reader with and without CAD. Of seven readers, 86 % and 71 % achieved a higher accuracy (segment-level AUC) when using CAD as second and concurrent reader respectively. Average segment-level AUCs with second and concurrent CAD (0.853 and 0.864) were significantly greater (p < 0.0001) than average AUC in the unaided evaluation (0.781). Per-segment, per-polyp, and per-patient sensitivities for polyps ≥6 mm were significantly higher in both CAD reading paradigms compared with unaided evaluation. Second-read CAD reduced readers' average segment and patient specificity by 0.007 and 0.036 (p = 0.005 and 0.011), respectively. CAD significantly improves the sensitivities of radiologists moderately experienced in CTC for polyp detection, both as second reader and concurrent reader. (orig.)

  11. CT colonography interpretation times: effect of reader experience, fatigue, and scan findings in a multi-centre setting

    Energy Technology Data Exchange (ETDEWEB)

    Burling, David; Bartram, Clive; De Villiers, Melinda; Honeyfield, Lesley [St. Marks Hospital, Intestinal Imaging Centre, London (United Kingdom); Halligan, Steve; Taylor, Stuart [University College Hospital, Specialist Radiology, Level 2 Podium, London (United Kingdom); Altman, Douglas G. [Centre for Medical Statistics, Oxford (United Kingdom); Atkin, Wendy [St Mark' s Hospital, Cancer Research UK, London (United Kingdom); Fenlon, Helen; Foley, Shane; O' Hare, Alan [Mater Misericordiae, Dublin (Ireland); Laghi, Andrea; Iannaccone, Riccardo; Mangiapane, Filipo; Ori, Sante [La Sapienza, Rome (Italy); Stoker, Jaap; Florie, Jasper; Poulus, Martin; Hulst, Victor van der [Amsterdam Medical Centre, Amsterdam (Netherlands); Frost, Roger [Salisbury District Hospital, Salisbury (United Kingdom); Dessey, Guido; Lefere, Philippe; Marrannes, Jesse [Stedelijk Ziekenhuis, Roeselare (Belgium); Gallo, Teresa; Nieddu, Giulia; Regge, Daniele; Signoretta, Saverio [Candiolo Oncologic Hospital, Turin (Italy); Kay, Clive; Lowe, Andrew; Williams-Butt, Jane [Bradford Royal Infirmary, Bradford (United Kingdom); Neri, Emmanuele; Politi, Benedetta; Vagli, Paola [University of Pisa, Pisa (Italy); Nicholson, David; Renaut, Lisa; Rudralingham, Velauthan [Hope Hospital, Salford (United Kingdom)

    2006-08-15

    Our purpose was to assess the effect of reader experience, fatigue, and scan findings on interpretation time for CT colonography. Nine radiologists (experienced in CT colonography); nine radiologists and ten technicians (both groups trained using 50 validated examinations) read 40 cases (50% abnormal) under controlled conditions. Individual interpretation times for each case were recorded, and differences between groups determined. Multi-level linear regression was used to investigate effect of scan category (normal or abnormal) and observer fatigue on interpretation times. Experienced radiologists (mean time 10.9 min, SD 5.2) reported significantly faster than less experienced radiologists and technicians; odds ratios of reporting times 1.4 (CI 1.1, 1.8) and 1.6 (1.3, 2.0), respectively (P{<=}0.001). Experienced and less-experienced radiologists took longer to report abnormal cases; ratio 1.2 (CI 1.1,1.4, P<0.001) and 1.2 (1.0, 1.3, P=0.03), respectively. All groups took 70% as long to report the final five cases as they did with an initial five; ratio 0.7 (CI 0.6 to 0.8), P<0.001. For technicians only, accuracy increased with longer reporting times (P=0.04). Experienced radiologists report faster than do less-experienced observers and proportionally spend less time interpreting normal cases. Technicians who report more slowly are more accurate. All groups reported faster as the study period progressed. (orig.)

  12. CT Colonography: Role of a second reader CAD paradigm in the initial training of radiologists

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele, E-mail: eneri@sirm.org [Diagnostic and Interventional Radiology, University of Pisa (Italy); Faggioni, Lorenzo [Diagnostic and Interventional Radiology, University of Pisa (Italy); Regge, Daniele [Institute for Cancer Research and Treatment, Candiolo (Italy); Vagli, Paola; Turini, Francesca; Cerri, Francesca; Picano, Eugenia; Giusti, Sabina; Bartolozzi, Carlo [Diagnostic and Interventional Radiology, University of Pisa (Italy)

    2011-11-15

    Purpose: To evaluate the influence of CAD for the evaluation of CT colonography (CTC) datasets by inexperienced readers during the attendance of a dedicated hands-on training course. Method and materials: Twenty-seven radiologists inexperienced in CTC (11 with no CTC training at all, 16 having previously reviewed no more than 10 CTC cases overall) attended a hands-on training course based on direct teaching on fifteen workstations (four Advantage Windows 4.4 with Colon VCAR software, GE; six CADCOLON, Im3D; five ColonScreen (Toshiba/Voxar) with ColonCAD{sup TM} API, Medicsight). During the course, readers were instructed to analyze 26 CTC cases including 38 colonic lesions obtained through low-dose MDCT acquisitions, consisting of 12 polyps sized less than 6 mm, 9 polyps sized between 6 and 10 mm, 12 polyps sized between 11 mm and 30 mm, and 5 colonic masses sized >3 cm. CTC images were reviewed by each reader both in 2D and 3D mode, respectively by direct evaluation of native axial images and MPR reconstructions, and virtual endoscopy or dissected views. Each reader had 15 min time for assessing each dataset without CAD, after which results were compared with those provided by CAD software. Global rater sensitivity for each lesion size before and after CAD usage was compared by means of two-tailed Student's t test, while sensitivity of each single reader before and after CAD usage was assessed with the McNemar test. Results: For lesions sized <6 mm, global rater sensitivity was 0.1852 {+-} 0.1656 (mean {+-} SD) before CAD-assisted reading and 0.2345 {+-} 0.1761 after CAD (p = 0.0018). For lesions sized 6-9 mm, sensitivity was 0.2870 {+-} 0.1016 before CAD-assisted reading and 0.3117 {+-} 0.1099 after CAD (p = 0.0027). For lesions sized 10-30 mm, sensitivity was 0.5308 {+-} 0.2120 before CAD-assisted reading and 0.5637 {+-} 0.2133 after CAD (p = 0.0086), while for lesions sized >30 mm, sensitivity before CAD-assisted reading was 0.3556 {+-} 0.3105 and did not

  13. CT colonography: effect of computer-aided detection of colonic polyps as a second and concurrent reader for general radiologists with moderate experience in CT colonography.

    Science.gov (United States)

    Mang, Thomas; Bogoni, Luca; Anand, Vikram X; Chandra, Dass; Curtin, Andrew J; Lev-Toaff, Anna S; Hermosillo, Gerardo; Noah, Ralph; Raykar, Vikas; Salganicoff, Marcos; Shaw, Robert; Summerton, Susan; Tappouni, Rafel F R; Ringel, Helmut; Weber, Michael; Wolf, Matthias; Obuchowski, Nancy A

    2014-07-01

    To assess the effectiveness of computer-aided detection (CAD) as a second reader or concurrent reader in helping radiologists who are moderately experienced in computed tomographic colonography (CTC) to detect colorectal polyps. Seventy CTC datasets (34 patients: 66 polyps ≥6 mm; 36 patients: no abnormalities) were retrospectively reviewed by seven radiologists with moderate CTC experience. After primary unassisted evaluation, a CAD second read and, after a time interval of ≥4 weeks, a CAD concurrent read were performed. Areas under the receiver operating characteristic (ROC) curve (AUC), along with per-segment, per-polyp and per-patient sensitivities, and also reading times, were calculated for each reader with and without CAD. Of seven readers, 86% and 71% achieved a higher accuracy (segment-level AUC) when using CAD as second and concurrent reader respectively. Average segment-level AUCs with second and concurrent CAD (0.853 and 0.864) were significantly greater (p readers' average segment and patient specificity by 0.007 and 0.036 (p = 0.005 and 0.011), respectively. CAD significantly improves the sensitivities of radiologists moderately experienced in CTC for polyp detection, both as second reader and concurrent reader. • CAD helps radiologists with moderate CTC experience to detect polyps ≥6 mm. • Second and concurrent read CAD increase the radiologist's sensitivity for detecting polyps ≥6 mm. • Second read CAD slightly decreases specificity compared with an unassisted read. • Concurrent read CAD is significantly more time-efficient than second read CAD.

  14. Current techniques in the performance, interpretation, and reporting of CT colonography.

    Science.gov (United States)

    Poullos, Peter D; Beaulieu, Christopher F

    2010-04-01

    The technical objective of computed tomographic colonography (CTC) is to acquire high-quality computed tomography images of the cleansed, well-distended colon for polyp detection. In this article the authors provide an overview of the technical components of CTC, from preparation of the patient to acquisition of the imaging data and basic methods of interpretation. In each section, the best evidence for current practices and recommendations is reviewed. Each of the technical components must be optimized to achieve high sensitivity in polyp detection.

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

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

  16. Evaluation of dose reduction and image quality in CT colonography: Comparison of low-dose CT with iterative reconstruction and routine-dose CT with filtered back projection

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Koichi [Kameda Medical Center, Department of Radiology, Kamogawa, Chiba (Japan); Jichi Medical University, Department of Radiology, Tochigi (Japan); National Cancer Center, Cancer Screening Technology Division, Research Center for Cancer Prevention and Screening, Tokyo (Japan); Fujiwara, Masanori; Mogi, Tomohiro; Iida, Nao [Kameda Medical Center Makuhari, Department of Radiology, Chiba (Japan); Kanazawa, Hidenori; Sugimoto, Hideharu [Jichi Medical University, Department of Radiology, Tochigi (Japan); Mitsushima, Toru [Kameda Medical Center Makuhari, Department of Gastroenterology, Chiba (Japan); Lefor, Alan T. [Jichi Medical University, Department of Surgery, Tochigi (Japan)

    2015-01-15

    To prospectively evaluate the radiation dose and image quality comparing low-dose CT colonography (CTC) reconstructed using different levels of iterative reconstruction techniques with routine-dose CTC reconstructed with filtered back projection. Following institutional ethics clearance and informed consent procedures, 210 patients underwent screening CTC using automatic tube current modulation for dual positions. Examinations were performed in the supine position with a routine-dose protocol and in the prone position, randomly applying four different low-dose protocols. Supine images were reconstructed with filtered back projection and prone images with iterative reconstruction. Two blinded observers assessed the image quality of endoluminal images. Image noise was quantitatively assessed by region-of-interest measurements. The mean effective dose in the supine series was 1.88 mSv using routine-dose CTC, compared to 0.92, 0.69, 0.57, and 0.46 mSv at four different low doses in the prone series (p < 0.01). Overall image quality and noise of low-dose CTC with iterative reconstruction were significantly improved compared to routine-dose CTC using filtered back projection. The lowest dose group had image quality comparable to routine-dose images. Low-dose CTC with iterative reconstruction reduces the radiation dose by 48.5 to 75.1 % without image quality degradation compared to routine-dose CTC with filtered back projection. (orig.)

  17. Indications for and results of CT colonography: from screening to the symptomatic patient; Indikationen und Ergebnisse der CT-Kolonographie: von der Vorsorge bis zum symptomatischen Patienten

    Energy Technology Data Exchange (ETDEWEB)

    Graser, A.; Becker, C.R.; Reiser, M.F. [Klinikum Grosshadern der LMU Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany); Mang, T. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiodiagnostik, AKH Wien, Wien (Austria)

    2008-02-15

    CT colonography (CTC) is also referred to as virtual colonoscopy and is being used with increasing frequency in radiological practice. While there are still no generally accepted, clear-cut indications for its use in mass colorectal cancer screening, there is evidence that this investigation is useful in patients in whom colonoscopy has not been successful or who have known stenotic lesions in the colon. Recent results of significant comparative studies of CTC and conventional colonoscopy will have some influence on the future place of CTC in screening for cancer of the bowel; they show the great potential of CT-aided bowel examination. (orig.) [German] Die CT-Kolonographie (CTK), auch als virtuelle Koloskopie bezeichnet, wird zunehmend in der radiologischen Praxis eingesetzt. Waehrend fuer die reine Vorsorgeuntersuchung z. Z. noch keine rechtfertigende Indikation besteht, koennen symptomatische Patienten nach fehlgeschlagener Koloskopie oder zur Beurteilung des Darms proximal einer Stenose mittels CTK untersucht werden. Ergebnisse wichtiger Studien, die die CT-Kolonographie mit der herkoemmlichen Koloskopie vergleichen, beeinflussen die zukuenftige Position der Untersuchungsmethode beim Darmkrebsscreening. Vergleichsstudien mit der Koloskopie zeigen das grosse Potenzial der CT-gestuetzten Darmuntersuchung. (orig.)

  18. Assessment of the Incremental Benefit of Computer-Aided Detection (CAD) for Interpretation of CT Colonography by Experienced and Inexperienced Readers.

    Science.gov (United States)

    Boone, Darren; Mallett, Susan; McQuillan, Justine; Taylor, Stuart A; Altman, Douglas G; Halligan, Steve

    2015-01-01

    To quantify the incremental benefit of computer-assisted-detection (CAD) for polyps, for inexperienced readers versus experienced readers of CT colonography. 10 inexperienced and 16 experienced radiologists interpreted 102 colonography studies unassisted and with CAD utilised in a concurrent paradigm. They indicated any polyps detected on a study sheet. Readers' interpretations were compared against a ground-truth reference standard: 46 studies were normal and 56 had at least one polyp (132 polyps in total). The primary study outcome was the difference in CAD net benefit (a combination of change in sensitivity and change in specificity with CAD, weighted towards sensitivity) for detection of patients with polyps. Inexperienced readers' per-patient sensitivity rose from 39.1% to 53.2% with CAD and specificity fell from 94.1% to 88.0%, both statistically significant. Experienced readers' sensitivity rose from 57.5% to 62.1% and specificity fell from 91.0% to 88.3%, both non-significant. Net benefit with CAD assistance was significant for inexperienced readers but not for experienced readers: 11.2% (95%CI 3.1% to 18.9%) versus 3.2% (95%CI -1.9% to 8.3%) respectively. Concurrent CAD resulted in a significant net benefit when used by inexperienced readers to identify patients with polyps by CT colonography. The net benefit was nearly four times the magnitude of that observed for experienced readers. Experienced readers did not benefit significantly from concurrent CAD.

  19. [Virtual reality in MR colonography].

    Science.gov (United States)

    Schoenfelder, D; Debatin, J F

    2000-03-01

    Early detection and subsequent removal of colorectal polyps have been shown to constitute an effective approach for decreasing the incidence of colorectal cancer. The lack of an ideal modality for colorectal polyp screening stimulated interest in the development of CT-colonography and MR-colonography. Both techniques allow the colon to be analyzed in a cross-sectional as well as a virtual endoscopic format. Causing no side-effects and not concerning for radiation exposure MR-colonography warrants further consideration. Additional to detecting polyps down to 6 mm in size the inner wall contour and the morphology of the colonic wall itself can be assessed. New developments like fecal tagging will increase patients acceptance comparing to other diagnostic techniques. In search of an ideal modality for polyp screening MR-colonography will become a potent option in the diagnostic arsenal.

  20. Vascular map combined with CT colonography for evaluating candidates for laparoscopic colorectal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Flor, Nicola; Ceretti, Andrea Pisani; Maroni, Nirvana; Opocher, Enrico; Cornalba, Gianpaolo [Azienda Ospedaliera San Paolo, Milan (Italy); Campari, Alessandro; Ravelli, Anna; Lombardi, Maria Antonietta [University degli Studi di Milano, Milan (Italy)

    2015-08-15

    Contrast-enhanced computed tomography colonography (CE-CTC) is a useful guide for the laparoscopic surgeon to avoid incorrectly removing the colonic segment and the failure to diagnose of synchronous colonic and extra-colonic lesions. Lymph node dissection and vessel ligation under a laparoscopic approach can be time-consuming and can damage vessels and organs. Moreover, mesenteric vessels have extreme variations in terms of their courses and numbers. We describe the benefit of using an abdominal vascular map created by CE-CTC in laparoscopic colorectal surgery candidates. We describe patients with different diseases (colorectal cancer, diverticular disease, and inflammatory bowel disease) who underwent CE-CTC just prior to laparoscopic surgery.

  1. Vascular Map Combined with CT Colonography for Evaluating Candidates for Laparoscopic Colorectal Surgery

    Science.gov (United States)

    Campari, Alessandro; Ravelli, Anna; Lombardi, Maria Antonietta; Pisani Ceretti, Andrea; Maroni, Nirvana; Opocher, Enrico; Cornalba, Gianpaolo

    2015-01-01

    Contrast-enhanced computed tomography colonography (CE-CTC) is a useful guide for the laparoscopic surgeon to avoid incorrectly removing the colonic segment and the failure to diagnose of synchronous colonic and extra-colonic lesions. Lymph node dissection and vessel ligation under a laparoscopic approach can be time-consuming and can damage vessels and organs. Moreover, mesenteric vessels have extreme variations in terms of their courses and numbers. We describe the benefit of using an abdominal vascular map created by CE-CTC in laparoscopic colorectal surgery candidates. We describe patients with different diseases (colorectal cancer, diverticular disease, and inflammatory bowel disease) who underwent CE-CTC just prior to laparoscopic surgery. PMID:26175581

  2. Exploration of analysis methods for diagnostic imaging tests: problems with ROC AUC and confidence scores in CT colonography.

    Science.gov (United States)

    Mallett, Susan; Halligan, Steve; Collins, Gary S; Altman, Doug G

    2014-01-01

    Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests.

  3. Electronic cleansing for CT colonography: does it help CAD software performance in a high-risk population for colorectal cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Wi, Jae Yeon [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea); Kim, Se Hyung; Lee, Jae Young; Han, Joon Koo; Choi, Byung Ihn [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea); Seoul National University Hospital, Institute of Radiation Medicine, Seoul (Korea); Kim, Sang Gyun [Seoul National University Hospital, Department of Internal Medicine, Seoul (Korea)

    2010-08-15

    To compare the performance of computer-aided detection (CAD) for CT colonography (CTC) with and without electronic cleansing (EC) in a high-risk population tagged with a faecal tagging (FT) protocol. Thirty-two patients underwent CTC followed by same-day colonoscopy. All patients underwent bowel preparation and FT with barium and gastrografin. Each CTC dataset was processed with colon CAD with and without EC. Per-polyp sensitivity was calculated. The average number of false-positive (FP) results and their causes were also analysed and compared. Eighty-six polyps were detected in 29 patients. Per-polyp sensitivities of CAD with EC (93.8% and 100%) were higher than those without EC (84.4% and 87.5%) for polyps {>=}6 mm and {>=}10 mm, respectively. However, the differences were not significant. The average number (6.3) of FPs of CAD with EC was significantly larger than that (3.1) without EC. The distribution of FPs in both CAD settings was also significantly different. The most common cause of FPs was the ileocaecal valve in both datasets. However, untagged faeces was a significantly less common cause of FPs with EC, EC-related artefacts being more common. Electronic cleansing has the potential to improve per-polyp sensitivity of CTC CAD, although the significantly larger number of FPs with EC remains to be improved. (orig.)

  4. CT colonography: optimisation, diagnostic performance and patient acceptability of reduced-laxative regimens using barium-based faecal tagging

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Stuart A. [University College Hospital, Department of Specialist Radiology, London (United Kingdom); University College Hospital, Department of Imaging, London (United Kingdom); Slater, Andrew [John Radcliffe Hospital, Oxford (United Kingdom); Burling, David N.; Tam, Emily; Gartner, Louise; Scarth, Julia; Bassett, Paul [St Mark' s Hospital, Northwick Park (United Kingdom); Greenhalgh, Rebecca; Pearce, Robert; Halligan, Steve [University College Hospital, Department of Specialist Radiology, London (United Kingdom)

    2008-01-15

    To establish the optimum barium-based reduced-laxative tagging regimen prior to CT colonography (CTC). Ninety-five subjects underwent reduced-laxative (13 g senna/18 g magnesium citrate) CTC prior to same-day colonoscopy and were randomised to one of four tagging regimens using 20 ml 40%w/v barium sulphate: regimen A: four doses, B: three doses, C: three doses plus 220 ml 2.1% barium sulphate, or D: three doses plus 15 ml diatriazoate megluamine. Patient experience was assessed immediately after CTC and 1 week later. Two radiologists graded residual stool (1: none/scattered to 4: >50% circumference) and tagging efficacy for stool (1: untagged to 5: 100% tagged) and fluid (1: untagged, 2: layered, 3: tagged), noting the HU of tagged fluid. Preparation was good (76-94% segments graded 1), although best for regimen D (P = 0.02). Across all regimens, stool tagging quality was high (mean 3.7-4.5) and not significantly different among regimens. The HU of layered tagged fluid was higher for regimens C/D than A/B (P = 0.002). Detection of cancer (n = 2), polyps {>=}6 mm (n = 21), and {<=}5 mm (n = 72) was 100, 81 and 32% respectively, with only four false positives {>=}6 mm. Reduced preparation was tolerated better than full endoscopic preparation by 61%. Reduced-laxative CTC with three doses of 20 ml 40% barium sulphate is as effective as more complex regimens, retaining adequate diagnostic accuracy. (orig.)

  5. Uni- and bidirectional wide angle CT colonography: effect on missed areas, surface visualization, viewing time and polyp conspicuity

    Energy Technology Data Exchange (ETDEWEB)

    East, James E.; Saunders, Brian P. [St. Mark' s Hospital, Wolfson Unit for Endoscopy, London (United Kingdom); Boone, Darren; Halligan, Steve; Taylor, Stuart A. [University College Hospital, Department of Specialist Radiology, London (United Kingdom); Burling, David [St. Mark' s Hospital, Department of Intestinal Imaging, London (United Kingdom)

    2008-09-15

    The effect of field of view on mucosal visualisation and reader efficiency during three-dimensional endoluminal CT colonography (CTC) was investigated. Twenty CTC datasets were reviewed at standard 90-degree and ''wide'' 140-degree viewing angles using customised viewing software (V3D colon; Viatronix), which listed number and size of missed mucosal areas (''missed regions tool'') and percentage mucosal visualisation. We compared: (1) unidirectional and bidirectional flythrough using 140- versus 90-degree viewing angles; (2) reader analysis time comparing unidirectional 140-degree flythrough versus bidirectional 90-degree flythrough; (3) paired image snapshots of 12 polyps taken at each field of view were reviewed to assess conspicuity. All patients underwent conventional colonoscopy. Bidirectional 140-degree review reduced the numbers of missed areas by between eight- and 40-fold depending on size category, including those >1,000 mm{sup 2}, compared with standard 90-degree bidirectional flythrough (P<0.001). Combined prone-supine unidirectional 140-degree flythrough and missed area review was 3.8 min faster than 90-degree bidirectional review (9.3 versus 5.5 min, P< 0.0001) for the same surface visualisation. When viewed as pairs, polyps were rated more conspicuous with a 90-degree field of view, P=0.03. Wide-angle (140-degree) CTC can reduce both numbers of missed areas and review times. However, this may be at the expense of polyp conspicuity. (orig.)

  6. The effect of computer-aided detection markers on visual search and reader performance during concurrent reading of CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Helbren, Emma; Taylor, Stuart A. [University College London, Centre for Medical Imaging, London (United Kingdom); Fanshawe, Thomas R.; Mallett, Susan [University of Oxford, Nuffield Department of Primary Care Health Sciences, Oxford (United Kingdom); Phillips, Peter [University of Cumbria, Health and Medical Sciences Group, Lancaster (United Kingdom); Boone, Darren [Colchester Hospital University NHS Foundation Trust and Anglia University, Colchester (United Kingdom); Gale, Alastair [Loughborough University, Applied Vision Research Centre, Loughborough (United Kingdom); Altman, Douglas G. [University of Oxford, Centre for Statistics in Medicine, Oxford (United Kingdom); Manning, David [Lancaster University, Lancaster Medical School, Faculty of Health and Medicine, Lancaster (United Kingdom); Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); University College Hospital, Gastrointestinal Radiology, University College London, Centre for Medical Imaging, Podium Level 2, London, NW1 2BU (United Kingdom)

    2015-06-01

    We aimed to identify the effect of computer-aided detection (CAD) on visual search and performance in CT Colonography (CTC) of inexperienced and experienced readers. Fifteen endoluminal CTC examinations were recorded, each with one polyp, and two videos were generated, one with and one without a CAD mark. Forty-two readers (17 experienced, 25 inexperienced) interpreted the videos during infrared visual search recording. CAD markers and polyps were treated as regions of interest in data processing. This multi-reader, multi-case study was analysed using multilevel modelling. CAD drew readers' attention to polyps faster, accelerating identification times: median 'time to first pursuit' was 0.48 s (IQR 0.27 to 0.87 s) with CAD, versus 0.58 s (IQR 0.35 to 1.06 s) without. For inexperienced readers, CAD also held visual attention for longer. All visual search metrics used to assess visual gaze behaviour demonstrated statistically significant differences when ''with'' and ''without'' CAD were compared. A significant increase in the number of correct polyp identifications across all readers was seen with CAD (74 % without CAD, 87 % with CAD; p < 0.001). CAD significantly alters visual search and polyp identification in readers viewing three-dimensional endoluminal CTC. For polyp and CAD marker pursuit times, CAD generally exerted a larger effect on inexperienced readers. (orig.)

  7. Computer-assisted detection of colonic polyps with CT colonography using neural networks and binary classification trees.

    Science.gov (United States)

    Jerebko, Anna K; Summers, Ronald M; Malley, James D; Franaszek, Marek; Johnson, C Daniel

    2003-01-01

    Detection of colonic polyps in CT colonography is problematic due to complexities of polyp shape and the surface of the normal colon. Published results indicate the feasibility of computer-aided detection of polyps but better classifiers are needed to improve specificity. In this paper we compare the classification results of two approaches: neural networks and recursive binary trees. As our starting point we collect surface geometry information from three-dimensional reconstruction of the colon, followed by a filter based on selected variables such as region density, Gaussian and average curvature and sphericity. The filter returns sites that are candidate polyps, based on earlier work using detection thresholds, to which the neural nets or the binary trees are applied. A data set of 39 polyps from 3 to 25 mm in size was used in our investigation. For both neural net and binary trees we use tenfold cross-validation to better estimate the true error rates. The backpropagation neural net with one hidden layer trained with Levenberg-Marquardt algorithm achieved the best results: sensitivity 90% and specificity 95% with 16 false positives per study.

  8. Phase- and size-adjusted CT cut-off for differentiating neoplastic lesions from normal colon in contrast-enhanced CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Luboldt, W. [University Hospital Frankfurt, Department of Radiology, Frankfurt (Germany); Multiorgan Screening Foundation, Frankfurt (Germany); University Hospital Essen, Clinic of Angiology, Essen (Germany); Kroll, M.; Wetter, A.; Vogl, T.J. [University Hospital Frankfurt, Department of Radiology, Frankfurt (Germany); Toussaint, T.L. [Multiorgan Screening Foundation, Frankfurt (Germany); Hoepffner, N. [University Hospital Frankfurt, Department of Internal Medicine, Frankfurt (Germany); Holzer, K. [University Hospital Frankfurt, Department of Visceral and Vascular Surgery, Frankfurt (Germany); Kluge, A. [Kerckhoff Heart Center, Department of Radiology, Bad Nauheim (Germany)

    2004-12-01

    A computed tomography (CT) cut-off for differentiating neoplastic lesions (polyps/carcinoma) from normal colon in contrast-enhanced CT colonography (CTC) relating to the contrast phase and lesion size is determined. CT values of 64 colonic lesions (27 polyps <10 mm, 13 polyps {>=}10 mm, 24 carcinomas) were determined by region-of-interest (ROI) measurements in 38 patients who underwent contrast-enhanced CTC. In addition, the height (H) of the colonic lesions was measured in CT. CT values were also measured in the aorta (A), superior mesenteric vein (V) and colonic wall. The contrast phase was defined by xA + (1 - x)V using x as a weighting factor for describing the different contrast phases ranging from the pure arterial phase (x=1) over the intermediate phases (x=0.9-0.1) to the pure venous phase (x=0). The CT values of the lesions were correlated with their height (H), the different phases (xA + (1 - x)V) and the ratio [xA + (1 - x)V]/H. The CT cut-off was linearly adjusted to the imaged contrast phase and height of the lesion by the line y = m[xA + (1 - x)V]/H + y{sub 0}. The slope m was determined by linear regression in the correlation (lesion {proportional_to}[xA + (1 - x)V]//H) and the Y-intercept y{sub 0} by the minimal shift of the line needed to maximize the accuracy of separating the colonic wall from the lesions. The CT value of the lesions correlated best with the intermediate phase: 0.4A+ 0.6V(r=0.8 for polyps {>=}10 mm, r=0.6 for carcinomas, r=0.4 for polyps <10 mm). The accuracy in the differentiation between lesions and normal colonic wall increased with the height implemented as divisor, reached 91% and was obtained by the dynamic cut-off described by the formula: cut-off(A,V,H) = 1.1[0.4A + 0.6V]/H + 69.8. The CT value of colonic polyps or carcinomas can be increased extrinsically by scanning in the phase in which 0.4A + 0.6V reaches its maximum. Differentiating lesions from normal colon based on CT values is possible in contrast-enhanced CTC and

  9. Extracolonic findings (ECF) on CT colonography (CTC) in patients presenting with colorectal symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Sarit Badiani, Sarit; Karandikar, Sharad [Dept. of General Surgery, Heart of England Foundation Trust, Birmingham (United Kingdom); Tomas-Hernandez, Silvia; Roy-Choudhury; Shuvro [Dept. of Radiology, Heart of England Foundation Trust, Birmingham (United Kingdom)], e-mail: shurvrorc@googlemail.com

    2013-10-15

    Background: Computed tomographic colonography (CTC) is now an established method for imaging the colon and rectum in the screening and symptomatic setting. Additional benefit of CTC is the ability to assess for extracolonic findings especially in patients presenting with colorectal symptoms. Purpose: To determine prevalence of extracolonic findings (ECF) in symptomatic patients undergoing CTC and determine accuracy of CTC for exclusion of significant abdominal disease and extracolonic malignancy (ECM). Material and Methods: A total of 1359 unenhanced prone and postcontrast supine CTC studies were performed between March 2002 and December 2007. ECF were retrospectively classified according to C-RADS criteria into E1 to E4 findings. For ECM, a gold standard of clinical and/or radiological follow-up supplemented with data from the regional cancer registry with a median follow-up of 42 months was created. Sensitivity and negative predictive values for ECM was calculated. Results: Following exclusions, 1177 CTCs were analyzed. Of 1423 extracolonic findings reported, 328/1423 (23%) E3 and 100/1423 (7%) E4 (including six eventual FP studies) findings were identified. Thirty-two ECMs were confirmed following further investigations. Seven further small ECMs were detected during the entire follow-up, of which two were potentially visible in retrospect (false-negative studies). Additional tests were generated from 55/1177 (4.7%) studies. Sensitivity and negative predictive value for ECM was 94.1% (95% CI 78.9 - 98.9%) and 99.8% (95% CI 99.3 - 99.9%), respectively. Conclusion: One in 37 patients were found to have an ECM. Two potentially detectable cancers were missed. Only a small proportion of patients underwent additional work-up.

  10. Assessment of the Incremental Benefit of Computer-Aided Detection (CAD for Interpretation of CT Colonography by Experienced and Inexperienced Readers.

    Directory of Open Access Journals (Sweden)

    Darren Boone

    Full Text Available To quantify the incremental benefit of computer-assisted-detection (CAD for polyps, for inexperienced readers versus experienced readers of CT colonography.10 inexperienced and 16 experienced radiologists interpreted 102 colonography studies unassisted and with CAD utilised in a concurrent paradigm. They indicated any polyps detected on a study sheet. Readers' interpretations were compared against a ground-truth reference standard: 46 studies were normal and 56 had at least one polyp (132 polyps in total. The primary study outcome was the difference in CAD net benefit (a combination of change in sensitivity and change in specificity with CAD, weighted towards sensitivity for detection of patients with polyps.Inexperienced readers' per-patient sensitivity rose from 39.1% to 53.2% with CAD and specificity fell from 94.1% to 88.0%, both statistically significant. Experienced readers' sensitivity rose from 57.5% to 62.1% and specificity fell from 91.0% to 88.3%, both non-significant. Net benefit with CAD assistance was significant for inexperienced readers but not for experienced readers: 11.2% (95%CI 3.1% to 18.9% versus 3.2% (95%CI -1.9% to 8.3% respectively.Concurrent CAD resulted in a significant net benefit when used by inexperienced readers to identify patients with polyps by CT colonography. The net benefit was nearly four times the magnitude of that observed for experienced readers. Experienced readers did not benefit significantly from concurrent CAD.

  11. Using CT colonography as a triage technique after a positive faecal occult blood test in colorectal cancer screening

    Science.gov (United States)

    Liedenbaum, M H; van Rijn, A F; de Vries, A H; Dekker, H M; Thomeer, M; van Marrewijk, C J; Hol, L; Dijkgraaf, M G W; Fockens, P; Bossuyt, P M M; Dekker, E; Stoker, J

    2009-01-01

    Objective: The purpose of this study was to evaluate the effectiveness of CT colonography (CTC) as a triage technique in faecal occult blood test (FOBT)-positive screening participants. Methods: Consecutive guaiac (G-FOBT) and immunochemical (I-FOBT) FOBT-positive patients scheduled for colonoscopy underwent CTC with iodine tagging bowel preparation. Each CTC was read independently by two experienced observers. Per patient sensitivity, specificity and positive and negative predictive values (PPV and NPV) were calculated based on double reading with different CTC cut-off lesion sizes using segmental unblinded colonoscopy as the reference standard. The acceptability of the technique to patients was evaluated with questionnaires. Results: 302 FOBT-positive patients were included (54 G-FOBT and 248 I-FOBT). 22 FOBT-positive patients (7%) had a colorectal carcinoma and 211 (70%) had a lesion ⩾6 mm. Participants considered colonoscopy more burdensome than CTC (p<0.05). Using a 6 mm CTC size cut-off, per patient sensitivity for CTC was 91% (95% CI 85% to 91%) and specificity was 69% (95% CI 60% to 89%) for the detection of colonoscopy lesions ⩾6 mm. The PPV of CTC was 87% (95% CI 80% to 93%) and NPV 77% (95% CI 69% to 85%). Using CTC as a triage technique in 100 FOBT-positive patients would mean that colonoscopy could be prevented in 28 patients while missing ⩾10 mm lesions in 2 patients. Conclusion: CTC with limited bowel preparation has reasonable predictive values in an FOBT-positive population and a higher acceptability to patients than colonoscopy. However, due to the high prevalence of clinically relevant lesions in FOBT-positive patients, CTC is unlikely to be an efficient triage technique in a first round FOBT population screening programme. PMID:19625276

  12. Accuracy of single phase contrast enhanced multidetector CT colonography in the preoperative staging of colo-rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mainenti, Pier Paolo [IBB CNR, Via Pansini 5, 80131 Naples (Italy) and Department of Biomorphological and Functional Sciences, University of Naples ' Federico II' , Via Pansini 5, 80131 Naples (Italy)]. E-mail: pierpamainenti@hotmail.com; Cirillo, Luigi Carlo [Department of Biomorphological and Functional Sciences, University of Naples ' Federico II' , Via Pansini 5, 80131 Naples (Italy); Hospital ' dei Pellegrini' , ASLNA 1, Via Portamedina 41, 80100 Naples (Italy); Camera, Luigi [Department of Biomorphological and Functional Sciences, University of Naples ' Federico II' , Via Pansini 5, 80131 Naples (Italy); Persico, Francesco [Department of General Surgery, Geriatry and Endoscopy, University of Naples ' Federico II' , Via Pansini 5, 80131 Naples (Italy); Cantalupo, Teresa [Department of Biomorphological and Functional Sciences, University of Naples ' Federico II' , Via Pansini 5, 80131 Naples (Italy); Pace, Leonardo [Department of Biomorphological and Functional Sciences, University of Naples ' Federico II' , Via Pansini 5, 80131 Naples (Italy); Palma, Giovanni Domenico De [Department of General Surgery, Geriatry and Endoscopy, University of Naples ' Federico II' , Via Pansini 5, 80131 Naples (Italy); Persico, Giovanni [Department of General Surgery, Geriatry and Endoscopy, University of Naples ' Federico II' , Via Pansini 5, 80131 Naples (Italy); Salvatore, Marco [Department of Biomorphological and Functional Sciences, University of Naples ' Federico II' , Via Pansini 5, 80131 Naples (Italy)

    2006-12-15

    Aim: The optimal acquisition time for staging colo-rectal carcinoma with a contrast enhanced multidetector CT colonography (CE CTC) has not yet been established. A dual phase with both arterial and portal venous acquisition has been proposed. The purpose of our study is to assess the value of single portal venous phase CE CTC in the preoperative staging of colo-rectal carcinoma. Materials and methods: Fifty two (30 M, 22 F; aged 35-82 years) consecutive patients with a histologically proven diagnosis of colo-rectal adenocarcinoma or a highly suspected colo-rectal cancer on conventional colonoscopy underwent a four-slice CE CTC. The procedure was performed 70 s (portal phase) after the intravenous bolus (3 ml/s) administration of 120 ml iodinated non-ionic contrast agent (370 mg iodine/ml). Scans were performed using the following parameters: 2.5 mm beam collimation, pitch 1.25, 120 kV, 200 mAs, rotation time 0.75 s. Images were reconstructed with an effective thickness of 3.2 mm at intervals of 1.6 mm. Two radiologists independently evaluated the depth of tumour invasion into the colo-rectal wall (T), regional lymph node involvement (N), and extracolonic metastases (M). Disagreement was resolved by means of a consensus decision. The pathological results served as the standard of reference. Assessment was made of sensitivity, specificity and accuracy, as well as positive and negative predictive values were assessed. Results: CE CTC correctly staged the pT of 52/56 (93%) and the N of 40/56 (71%) lesions, as well as properly identifying 13/14 (93%) extracolonic findings. Conclusion: The single portal venous phase CE CTC scanning protocol enables satisfactory preoperative assessment of T, N and M staging in patients with colo-rectal cancer.

  13. Exploration of analysis methods for diagnostic imaging tests: problems with ROC AUC and confidence scores in CT colonography.

    Directory of Open Access Journals (Sweden)

    Susan Mallett

    Full Text Available BACKGROUND: Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. METHODS: In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. RESULTS: Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. CONCLUSIONS: The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests.

  14. Comparison between CT Colonography and Double-Contrast Barium Enema for Colonic Evaluation in Patients with Renal Insufficiency

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Sun Young; Park, Seong Ho; Lee, Seung Soo; Lee, Ju Hee; Kim, Ah Young; Park, Su Ki; Han, Duck Jong; Ha, Hyun Kwon [Asan Medical Center, Ulsan University College of Medicine, Seoul (Korea, Republic of)

    2012-06-15

    To compare the CT colonography (CTC) and double-contrast barium enema (DCBE) for colonic evaluation in patients with renal insufficiency. Two sequential groups of consecutive patients with renal insufficiency who had a similar risk for colorectal cancer, were examined by DCBE (n = 182; mean {+-} SD in age, 51 {+-} 6.4 years) and CTC (n = 176; 50 {+-} 6.7 years), respectively. CTC was performed after colon cleansing with 250-mL magnesium citrate (n = 87) or 4-L polyethylene glycol (n = 89) and fecal tagging. DCBE was performed after preparation with 250-mL magnesium citrate. Patients with colonic polyps/masses of {>=} 6 mm were subsequently recommended to undergo a colonoscopy. Diagnostic yield and positive predictive value (PPV) for colonic polyps/masses, examination quality, and examination-related serum electrolyte change were retrospectively compared between the two groups. Both the CTC and DCBE were positive for colonic polyps/masses in 28 (16%) of 176 and 11 (6%) of 182 patients, respectively (p = 0.004). Among patients with positive findings, 17 CTC and six DCBE patients subsequently underwent a colonoscopy and yielded a PPV of 88% (15 of 17 patients) and 50% (3 of 6 patients), respectively (p = 0.089). Thirteen patients with adenomatous lesions were detected in the CTC group (adenocarcinoma [n = 1], advanced adenoma [n = 6], and non-advanced adenoma [n = 6]), as compared with two patients (each with adenocarcinoma and advanced adenoma) in the DCBE group (p = 0.003). Six (3%) of 176 CTC and 16 (9%) of 182 DCBE examinations deemed to be inadequate (p 0.046). Electrolyte changes were similar in the two groups. In patients with renal insufficiency, CTC has a higher diagnostic yield and a marginally higher PPV for detecting colorectal neoplasia, despite a similar diagnostic yield for adenocarcinoma, and a lower rate of inadequate examinations as compared with DCBE.

  15. Effect of reducing abdominal compression during prone CT colonography on ascending colonic rotation during supine-to-prone positional change

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jong eon; Park, Seong Ho; Lee, Jong Seok; Kim, Hyun Jin; KIm, Ah Young; Ha, Hyun Kwon [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2016-02-15

    To determine the effect of reduced abdominal compression in prone position on ascending colonic movement during supine-to-prone positional change during CT colonography (CTC). Eighteen consecutive patients who had undergone prone CTC scanning with cushion blocks placed under the chest and hip/thigh to reduce abdominal compression and had confirmed sessile polyps ≥ 6 mm in the well-distended, straight, mid-ascending colon, were included. Radial location along the ascending colonic luminal circumference (°) was measured for 24 polyps and 54 colonic teniae on supine and prone CTC images. The supine-to-prone change ranging between -180° and +180° (- and + for internal and external colonic rotations, respectively), was determined. In addition, possible causes of any ascending colonic rotations were explored. Abdominal compression during prone CTC scanning completely disappeared with the use of cushion blocks in 17 of 18 patients. However, some degrees of ascending colonic rotation were still observed, with the radial location changes of -22° to 61° (median, 13.9°) for the polyps and similar degrees for teniae. Fifty-four percent and 56% of polyps and teniae, respectively, showed changes > 10°. The radial location change of the polyps was significantly associated with the degree of anterior shift of the small bowel and mesentery (r = 0.722, p < 0.001) and the degree of posterior displacement of the ascending colon (r = 0.566, p = 0.004) during supine-to-prone positional change. Ascending colonic rotation upon supine-to-prone positional change during CTC, mostly in the form of external rotation, is not eliminated by removing abdominal compression in prone position.

  16. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    Energy Technology Data Exchange (ETDEWEB)

    Plumb, Andrew A.; Taylor, Stuart A.; Halligan, Steve [University College London, Centre for Medical Imaging, Division of Medicine, London (United Kingdom); Ghanouni, Alex; Von Wagner, Christian [University College London, Health Behaviour Research Centre, Department of Epidemiology and Public Health, London (United Kingdom); Rees, Colin J. [Durham University School of Medicine, Pharmacy and Health, Durham (United Kingdom); Hewitson, Paul [University of Oxford, Health Services Research Unit, Nuffield Department of Population Health, Oxford (United Kingdom); Nickerson, Claire; Wright, Suzanne [Fulwood House, NHS Cancer Screening Programmes, Sheffield (United Kingdom)

    2017-03-15

    To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as complications. CTC and colonoscopy responses were compared using multilevel logistic regression. Of 67,114 subjects identified, 52,805 (79 %) responded. Understanding of test risks was lower for CTC (1712/1970 = 86.9 %) than colonoscopy (48783/50975 = 95.7 %, p < 0.0001). Overall, a slightly greater proportion of screenees found CTC unexpectedly uncomfortable (506/1970 = 25.7 %) than colonoscopy (10,705/50,975 = 21.0 %, p < 0.0001). CTC was tolerated well as a completion procedure for failed colonoscopy (unexpected discomfort; CTC = 26.3 %: colonoscopy = 57.0 %, p < 0.001). Post-procedural pain was equally common (CTC: 288/1970,14.6 %, colonoscopy: 7544/50,975,14.8 %; p = 0.55). Adverse event rates were similar in both groups (CTC: 20/2947 = 1.2 %; colonoscopy: 683/64,312 = 1.1 %), but generally less serious with CTC. Even though CTC was reserved for individuals either unsuitable for or unable to complete colonoscopy, we found only small differences in test-related discomfort. CTC was well tolerated as a completion procedure and was extremely safe. CTC can be delivered across a national screening programme with high patient satisfaction. (orig.)

  17. Patients' & healthcare professionals' values regarding true- & false-positive diagnosis when colorectal cancer screening by CT colonography: discrete choice experiment.

    Directory of Open Access Journals (Sweden)

    Darren Boone

    Full Text Available PURPOSE: To establish the relative weighting given by patients and healthcare professionals to gains in diagnostic sensitivity versus loss of specificity when using CT colonography (CTC for colorectal cancer screening. MATERIALS AND METHODS: Following ethical approval and informed consent, 75 patients and 50 healthcare professionals undertook a discrete choice experiment in which they chose between "standard" CTC and "enhanced" CTC that raised diagnostic sensitivity 10% for either cancer or polyps in exchange for varying levels of specificity. We established the relative increase in false-positive diagnoses participants traded for an increase in true-positive diagnoses. RESULTS: Data from 122 participants were analysed. There were 30 (25% non-traders for the cancer scenario and 20 (16% for the polyp scenario. For cancer, the 10% gain in sensitivity was traded up to a median 45% (IQR 25 to >85 drop in specificity, equating to 2250 (IQR 1250 to >4250 additional false-positives per additional true-positive cancer, at 0.2% prevalence. For polyps, the figure was 15% (IQR 7.5 to 55, equating to 6 (IQR 3 to 22 additional false-positives per additional true-positive polyp, at 25% prevalence. Tipping points were significantly higher for patients than professionals for both cancer (85 vs 25, p<0.001 and polyps (55 vs 15, p<0.001. Patients were willing to pay significantly more for increased sensitivity for cancer (p = 0.021. CONCLUSION: When screening for colorectal cancer, patients and professionals believe gains in true-positive diagnoses are worth much more than the negative consequences of a corresponding rise in false-positives. Evaluation of screening tests should account for this.

  18. High-performance computer aided detection system for polyp detection in CT colonography with fluid and fecal tagging

    Science.gov (United States)

    Liu, Jiamin; Wang, Shijun; Kabadi, Suraj; Summers, Ronald M.

    2009-02-01

    CT colonography (CTC) is a feasible and minimally invasive method for the detection of colorectal polyps and cancer screening. Computer-aided detection (CAD) of polyps has improved consistency and sensitivity of virtual colonoscopy interpretation and reduced interpretation burden. A CAD system typically consists of four stages: (1) image preprocessing including colon segmentation; (2) initial detection generation; (3) feature selection; and (4) detection classification. In our experience, three existing problems limit the performance of our current CAD system. First, highdensity orally administered contrast agents in fecal-tagging CTC have scatter effects on neighboring tissues. The scattering manifests itself as an artificial elevation in the observed CT attenuation values of the neighboring tissues. This pseudo-enhancement phenomenon presents a problem for the application of computer-aided polyp detection, especially when polyps are submerged in the contrast agents. Second, general kernel approach for surface curvature computation in the second stage of our CAD system could yield erroneous results for thin structures such as small (6-9 mm) polyps and for touching structures such as polyps that lie on haustral folds. Those erroneous curvatures will reduce the sensitivity of polyp detection. The third problem is that more than 150 features are selected from each polyp candidate in the third stage of our CAD system. These high dimensional features make it difficult to learn a good decision boundary for detection classification and reduce the accuracy of predictions. Therefore, an improved CAD system for polyp detection in CTC data is proposed by introducing three new techniques. First, a scale-based scatter correction algorithm is applied to reduce pseudo-enhancement effects in the image pre-processing stage. Second, a cubic spline interpolation method is utilized to accurately estimate curvatures for initial detection generation. Third, a new dimensionality

  19. Computer-aided polyp detection on CT colonography: Comparison of three systems in a high-risk human population

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hee Sun [Department of Radiology, Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Kim, Se Hyung, E-mail: shkim@radcom.snu.ac.k [Department of Radiology, Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Kim, Jong Hyo [Department of Radiology, Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine (Korea, Republic of); Lee, June-Goo [Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine (Korea, Republic of); Kim, Sang Gyun [Department of Internal Medicine, Seoul National University Hospital (Korea, Republic of); Lee, Jeong Min; Lee, Jae Young; Han, Joon Koo; Choi, Byung Ihn [Department of Radiology, Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of)

    2010-08-15

    Purpose: To compare the detection performances of two commercial and one academic computer-aided diagnosis (CAD) systems for polyp detection on CT colonography (CTC) in a high-risk human population and to assess their detection characteristics. Materials and methods: This retrospective study had institutional review board approval, but informed consent was waived. Sixty-eight patients who were suspected of having colonic polyps and scheduled for colonoscopic polyp removal were included. After CTC was performed using a 64-row MDCT, two commercial (PEV, CAR) and one academic (Hessian matrix-based) CAD systems were applied to each CTC dataset. Colonoscopy using the segmental unblinded technique was performed as a standard of reference. Per-polyp and per-patient sensitivities were calculated and compared for each CAD system. The mean number of false-positives (FPs) and false-negatives (FNs) was computed and the causes of all FPs and FNs were analyzed. Results: A total of 151 polyps in 61 patients were detected (77 polyps <6 mm, 48 6-9.9 mm, 26 {>=} 10 mm). Per-polyp sensitivity for PEV, CAR, and Hessian matrix-based CAD were: 71.6%, 78.4%, and 83.8% for polyps {>=}6 mm, and 88.5%, 96.2%, and 96.2% for polyps {>=}10 mm. Per-patient sensitivity for polyps {>=}6 mm was 80.4%, 89.1%, and 93.5%, and 87%, 95.7%, and 95.7% for polyps {>=}10 mm, respectively. Per-polyp and per-patient sensitivities were not significantly different among the three CAD systems regardless of size threshold. Mean number of FPs was 6.9 for PEV, 7.3 for CAR, and 14 for Hessian matrix-based CAD. The most common cause of FPs were feces, followed by extracolonic findings, prominent folds and ileocecal valve, and rectal tube. The distribution of the causes of FPs was significantly different among the three systems. Conclusion: Sensitivity of the three CAD systems for polyp detection was comparable regardless of the polyp size threshold; however, the number of FPs was higher in the Hessian matrix

  20. Effect of different reconstruction algorithms on computer-aided diagnosis (CAD) performance in ultra-low dose CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Sun [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Kim, Se Hyung, E-mail: shkim7071@gmail.com [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Im, Jong Pil; Kim, Sang Gyun [Department of Internal Medicine, Seoul National University Hospital (Korea, Republic of); Shin, Cheong-il; Han, Joon Koo; Choi, Byung Ihn [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of)

    2015-04-15

    Highlights: •We assessed the effect of reconstruction algorithms on CAD in ultra-low dose CTC. •30 patients underwent ultra-low dose CTC using 120 and 100 kVp with 10 mAs. •CT was reconstructed with FBP, ASiR and Veo and then, we applied a CAD system. •Per-polyp sensitivity of CAD in ULD CT can be improved with the IR algorithms. •Despite of an increase in the number of FPs with IR, it was still acceptable. -- Abstract: Purpose: To assess the effect of different reconstruction algorithms on computer-aided diagnosis (CAD) performance in ultra-low-dose CT colonography (ULD CTC). Materials and methods: IRB approval and informed consents were obtained. Thirty prospectively enrolled patients underwent non-contrast CTC at 120 kVp/10 mAs in supine and 100 kVp/10 mAs in prone positions, followed by same-day colonoscopy. Images were reconstructed with filtered back projection (FBP), 80% adaptive statistical iterative reconstruction (ASIR80), and model-based iterative reconstruction (MBIR). A commercial CAD system was applied and per-polyp sensitivities and numbers of false-positives (FPs) were compared among algorithms. Results: Mean effective radiation dose of CTC was 1.02 mSv. Of 101 polyps detected and removed by colonoscopy, 61 polyps were detected on supine and on prone CTC datasets on consensus unblinded review, resulting in 122 visible polyps (32 polyps <6 mm, 52 6–9.9 mm, and 38 ≥ 10 mm). Per-polyp sensitivity of CAD for all polyps was highest with MBIR (56/122, 45.9%), followed by ASIR80 (54/122, 44.3%) and FBP (43/122, 35.2%), with significant differences between FBP and IR algorithms (P < 0.017). Per-polyp sensitivity for polyps ≥ 10 mm was also higher with MBIR (25/38, 65.8%) and ASIR80 (24/38, 63.2%) than with FBP (20/38, 58.8%), albeit without statistical significance (P > 0.017). Mean number of FPs was significantly different among algorithms (FBP, 1.4; ASIR, 2.1; MBIR, 2.4) (P = 0.011). Conclusion: Although the performance of stand-alone CAD

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

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Kjel [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany)]. E-mail: kjel_andersen@web.de; Vogt, Christoph [Department of Gastroenterology, Hepatology and Infectiology, University Hospital Duesseldorf (Germany); Blondin, Dirk [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany); Beck, Andreas [Institute of Informatics, Heinrich-Heine-University, Duesseldorf (Germany); Heinen, Wolfram [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany); Aurich, Volker [Institute of Informatics, Heinrich-Heine-University, Duesseldorf (Germany); Haeussinger, Dieter [Department of Gastroenterology, Hepatology and Infectiology, University Hospital Duesseldorf (Germany); Moedder, Ulrich [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany); Cohnen, Mathias [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany)

    2006-04-15

    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.

  2. CT colonography with rectal iodine tagging: Feasibility and comparison with oral tagging in a colorectal cancer screening population

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele, E-mail: emanuele.neri@med.unipi.it [Diagnostic and Interventional Radiology – Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Italy); Mantarro, Annalisa; Faggioni, Lorenzo; Scalise, Paola; Bemi, Pietro; Pancrazi, Francesca [Diagnostic and Interventional Radiology – Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Italy); D’Ippolito, Giuseppe [Federal University of São Paulo – Sena Madureira 1500 – Vila Mariana, UNIFESP, São Paulo, SP (Brazil); Bartolozzi, Carlo [Diagnostic and Interventional Radiology – Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Italy)

    2015-09-15

    Highlights: • In the group receiving rectal tagging, mean per-polyp sensitivity, specificity were 96.1% and 95.3%; while in the group receiving oral tagging, mean per-polyp sensitivity, specificity were 89.4% and 95.8%. The difference between the two groups was not statistically significant (p = 0.549). • Rectal tagging can be an effective alternative to oral tagging. • Rectal tagging allowed greater patient acceptance and lower overall examination time. - Abstract: Purpose: To evaluate feasibility, diagnostic performance, patient acceptance, and overall examination time of CT colonography (CTC) performed through rectal administration of iodinated contrast material. Materials and methods: Six-hundred asymptomatic subjects (male:female = 270:330; mean 63 years) undergoing CTC for colorectal cancer screening on an individual basis were consecutively enrolled in the study. Out of them, 503 patients (group 1) underwent CTC with rectal tagging, of which 55 had a total of 77 colonic lesions. The remaining 97 patients (group 2) were randomly selected to receive CTC with oral tagging of which 15 had a total of 20 colonic lesions. CTC findings were compared with optical colonoscopy, and per-segment image quality was visually assessed using a semi-quantitative score (1 = poor, 2 = adequate, 3 = excellent). In 70/600 patients (11.7%), CTC was performed twice with both types of tagging over a 5-year follow-up cancer screening program. In this subgroup, patient acceptance was rated via phone interview two weeks after CTC using a semi-quantitative scale (1 = poor, 2 = fair, 3 = average, 4 = good, 5 = excellent). Results: Mean per-polyp sensitivity, specificity, positive and negative predictive values of CTC with rectal vs oral tagging were 96.1% (CI{sub 95%} 85.4 ÷ 99.3%) vs 89.4% (CI{sub 95%} 65.4 ÷ 98.1%), 95.3% (CI{sub 95%} 90.7 ÷ 97.8%) vs 95.8% (CI{sub 95%} 87.6 ÷ 98.9%), 86.0% (CI{sub 95%} 73.6 ÷ 93.3) vs 85.0% (CI{sub 95%} 61.1 ÷ 96.0%), and 98.8% (CI{sub 95

  3. CT Colonography (Virtual Colonoscopy)

    Science.gov (United States)

    ... passes through the body, recording an image on photographic film or a special image recording plate. Bones ... American College of Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise ...

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

  5. Non- or full-laxative CT colonography vs. endoscopic tests for colorectal cancer screening: A randomised survey comparing public perceptions and intentions to undergo testing

    Energy Technology Data Exchange (ETDEWEB)

    Ghanouni, Alex; Wardle, Jane; Von Wagner, Christian [University College London, Health Behaviour Research Centre, Department of Epidemiology and Public Health, London (United Kingdom); Halligan, Steve; Plumb, Andrew; Boone, Darren [University College London, Centre for Medical Imaging, London (United Kingdom)

    2014-07-15

    Compare public perceptions and intentions to undergo colorectal cancer screening tests following detailed information regarding CT colonography (CTC; after non-laxative preparation or full-laxative preparation), optical colonoscopy (OC) or flexible sigmoidoscopy (FS). A total of 3,100 invitees approaching screening age (45-54 years) were randomly allocated to receive detailed information on a single test and asked to return a questionnaire. Outcomes included perceptions of preparation and test tolerability, health benefits, sensitivity and specificity, and intention to undergo the test. Six hundred three invitees responded with valid questionnaire data. Non-laxative preparation was rated more positively than enema or full-laxative preparations [effect size (r) = 0.13 to 0.54; p < 0.0005 to 0.036]; both forms of CTC and FS were rated more positively than OC in terms of test experience (r = 0.26 to 0.28; all p-values < 0.0005). Perceptions of health benefits, sensitivity and specificity (p = 0.250 to 0.901), and intention to undergo the test (p = 0.213) did not differ between tests (n = 144-155 for each test). Despite non-laxative CTC being rated more favourably, this study did not find evidence that offering it would lead to substantially higher uptake than full-laxative CTC or other methods. However, this study was limited by a lower than anticipated response rate. (orig.)

  6. Panoramic endoluminal display with minimal image distortion using circumferential radial ray-casting for primary three-dimensional interpretation of CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Soo; Park, Seong Ho; Kim, Namkug; Lee, Jeongjin; Kim, Ah Young; Ha, Hyun Kwon [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea); Kim, Jin Kook [INFINITT Co., Ltd., Seoul (Korea); Park, Beom Jin [Korea University College of Medicine, Department of Radiology, Seoul (Korea); Kim, Young Jun [Konkuk University School of Medicine, Konkuk University Hospital, Department of Radiology, Seoul (Korea); Lee, Min Woo [Konkuk University School of Medicine, Konkuk University Hospital, Department of Radiology, Seoul (Korea); Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Radiology, Seoul (Korea)

    2009-08-15

    The purpose of this study was to develop a panoramic endoluminal display technique, the band view, which causes minimal image distortion, and to determine its feasibility as a time-efficient primary three-dimensional review method of CT colonography (CTC). Image distortion was compared between the band view and four other three-dimensional review modes using ten 10-mm and ten 20-mm electronically generated polyps. Diagnostic performance and interpretation time were compared between the band view and the conventional endoluminal view by two independent readers in 52 patients who underwent CTC and colonoscopy on the same day. Mean image distortion index values, in which 1 indicates no distortion and the larger value represents greater distortion, were significantly smaller with the band view (1.03 and 1.01 for 10-mm and 20-mm polyps, respectively) than with the filet view (1.65 and 1.55) or the virtual colon dissection (3.27 and 3.85) (P{<=}0.004). The sensitivity and specificity for detecting adenomatous polyps {>=}6 mm did not differ, but the mean interpretation time was significantly shorter with the band view than with the conventional endoluminal view by 1.8 and 4.5 minutes in readers 1 and 2, respectively (P<0.0001). The band view can be a time-efficient alternative for primary three-dimensional review of CTC. (orig.)

  7. Sensitivity and specificity of CT colonography for the detection of colonic neoplasia after positive faecal occult blood testing: systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Plumb, Andrew A.; Pendse, Douglas A.; Taylor, Stuart A. [University College London, Centre for Medical Imaging, London (United Kingdom); Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); University College London, University College Hospital, Centre for Medical Imaging, Podium Level 2, London (United Kingdom); Mallett, Susan [University of Oxford, Department of Primary Care Health Sciences, Oxford (United Kingdom)

    2014-05-15

    CT colonography (CTC) is recommended after positive faecal occult blood testing (FOBt) when colonoscopy is incomplete or infeasible. We aimed to estimate the sensitivity and specificity of CTC for colorectal cancer and adenomatous polyps following positive FOBt via systematic review. The MEDLINE, EMBASE, AMED and Cochrane Library databases were searched for CTC studies reporting sensitivity and specificity for colorectal cancer and adenomatous polyps. Included subjects had tested FOBt-positive by guaiac or immunochemical methods. Per-patient detection rates were summarized via forest plots. Meta-analysis of sensitivity and specificity was conducted using a bivariate random effects model and the average operating point calculated. Of 538 articles considered, 5 met inclusion criteria, describing results from 622 patients. Research study quality was good. CTC had a high per-patient average sensitivity of 88.8 % (95 % CI 83.6 to 92.5 %) for ≥6 mm adenomas or colorectal cancer, with low between-study heterogeneity. Specificity was both more heterogeneous and lower, at an average of 75.4 % (95 % CI 58.6 to 86.8 %). Few studies have investigated CTC in FOBt-positive individuals. CTC is sensitive at a ≥6 mm threshold but specificity is lower and variable. Despite the limited data, these results suggest that CTC may adequately substitute for colonoscopy when the latter is undesirable. (orig.)

  8. Time-efficient CT colonography interpretation using an advanced image-gallery-based, computer-aided "first-reader" workflow for the detection of colorectal adenomas.

    Science.gov (United States)

    Mang, Thomas; Hermosillo, Gerardo; Wolf, Matthias; Bogoni, Luca; Salganicoff, Marcos; Raykar, Vikas; Ringl, Helmut; Weber, Michael; Mueller-Mang, Christina; Graser, Anno

    2012-12-01

    To assess the performance of an advanced "first-reader" workflow for computer-aided detection (CAD) of colorectal adenomas ≥ 6 mm at computed tomographic colonography (CTC) in a low-prevalence cohort. A total of 616 colonoscopy-validated CTC patient-datasets were retrospectively reviewed by a radiologist using a "first-reader" CAD workflow. CAD detections were presented as galleries of six automatically generated two-dimensional (2D) and three-dimensional (3D) images together with interactive 3D target views and 2D multiplanar views of the complete dataset. Each patient-dataset was interpreted by initially using CAD image-galleries followed by a fast 2D review to address unprompted colonic areas. Per-patient, per-polyp, and per-adenoma sensitivities were calculated for lesions ≥ 6 mm. Statistical testing employed Fisher's exact and McNemar tests. In 91/616 patients, 131 polyps (92 adenomas, 39 non-adenomas) ≥ 6 mm and two cancers were identified by reference standard. Using the CAD gallery-based first-reader workflow, the radiologist detected all adenomas ≥ 10 mm (34/34) and cancers. Per-patient and polyp sensitivities for lesions ≥ 6 mm were 84.3 % (75/89), and 83.2 % (109/131), respectively, with 89.1 % (57/64) and 85.9 % (79/92) for adenomas. Overall specificity was 95.6 % (504/527). Mean interpretation time was 3.1 min per patient. A CAD algorithm, applied in an image-gallery-based first-reader workflow, can substantially decrease reading times while enabling accurate detection of colorectal adenomas in a low-prevalence population. Computer-aided detection (CAD) is increasingly used to help interpret CT colonography (CTC). An image-gallery first-reader CAD-workflow is feasible for detection of colorectal adenomas ≥ 6 mm. Image-gallery first-reader CAD yields per-patient sensitivity of 89.1 % and specificity of 95.6 %. The mean reading time for CTC was 3.1 min, making screening feasible. No large adenoma was missed by the radiologist who reviewed

  9. CT colonography versus colonoscopy in the follow-up of patients after diverticulitis - A prospective, comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Hjern, F. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden)]. E-mail: fredrik.hjern@ds.se; Jonas, E. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden); Holmstroem, B. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden); Josephson, T. [Division of Radiology, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm (Sweden); Mellgren, A. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden); Division of Colon and Rectal Surgery, University of Minnesota, Minneapolis, Minnesota (United States); Johansson, C. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden)

    2007-07-15

    Aim: To assess whether computed tomography colonography (CTC) is a viable alternative to colonoscopy or double contrast barium enema in the follow-up of patients after diverticulitis. Material and methods: Fifty patients underwent CTC followed immediately by colonoscopy. Results were blinded to the examiners. Findings of diverticular disease and patient acceptance were evaluated. Results: Bowel preparation and distension were good in the majority of CTC and colonoscopy examinations. Diverticular disease was found in 96% of patients at CTC and in 90% at colonoscopy. The rate of agreement between CTC and colonoscopy for diverticular findings in the sigmoid colon was good ({kappa} = 0.64). No complications were seen. Patients found colonoscopy more uncomfortable (p < 0.03), more painful (p < 0.001), and more difficult (p < 0.01) than CTC. Of the patients favouring one examination, 74% preferred CTC. Conclusion: CTC appears to have a better diagnostic potential for imaging of diverticular disease-specific findings, when compared with colonoscopy. Also, CTC was less uncomfortable and was preferred by a majority of patients. CTC seems to be a reasonable alternative in follow-up of patients with symptomatic diverticular disease.

  10. CT colonography in a Korean population with a high residue diet: Comparison between wet and dry preparations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.H. [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Choi, B.I. [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of)]. E-mail: choibi@radcom.snu.ac.kr; Han, J.K. [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital, Seoul (Korea, Republic of); Lee, J.M. [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital, Seoul (Korea, Republic of); Eun, H.W. [Ewha Woman' s University Hospital, Seoul (Korea, Republic of); Lee, J.Y. [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Lee, K.H. [Seoul National University Bundang Hospital, Seoul (Korea, Republic of); Han, C.J. [Health Care System, Seoul National University Hospital, Seoul (Korea, Republic of); Choi, Y.H. [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Shin, K.-S. [Chungnam National University Hospital, Seoul (Korea, Republic of)

    2006-06-15

    AIM: To compare wet and dry preparation methods for computed tomography colonography (CTC) in terms of preparation quality, interpretation time, and diagnostic performance for polyp detection in a population with a high residue diet. MATERIALS AND METHODS: Eighty-six patients were divided into two groups. Group 1 (n=24) received a wet preparation of 4 l polyethylene glycol (PEG) solution, and group 2 (n=62) received a dry preparation of phosphor-soda. Abnormal findings, including polyps, and the time required to interpret the CTC images in both groups were documented by a radiologist. CTC findings were compared to those of colonoscopy as a reference standard. Two radiologists evaluated the quality of CTC with regard to residual fluid, faeces, and colonic distension using a four-point scale in consensus. Statistical differences for residual fluid, faeces, distensibility on CTC, and interpretation time between the two groups were analysed. The diagnostic performance of CTC in both groups was also compared. RESULTS: One-hundred and ninety polyps in 70 patients were identified using colonoscopy. Regarding the quality of images produced the wet preparation was significantly better than the dry preparation (p<0.05). The average interpretation time was significantly shorter for the wet group (11.7 min) than the dry group (16.4 min) (p<0.05). For per-patient analysis, the positive predictive value (PPV) was significantly better for the wet (100%) than the dry group (79.6%; p=0.025). Sensitivities and PPV for {>=}10 mm polyps were comparable between two groups (p>0.05). CONCLUSION: In a population with a high-residue diet, CTC with wet preparation can be interpreted in a time-efficient manner and is comparable with CTC with dry preparation.

  11. Sub-milliSievert (sub-mSv) CT colonography: a prospective comparison of image quality and polyp conspicuity at reduced-dose versus standard-dose imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lubner, Meghan G.; Pooler, B.D.; Kitchin, Douglas R.; Kim, David H.; Munoz del Rio, Alejandro; Pickhardt, Perry J. [University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, Departments of Radiology, Madison, WI (United States); Tang, Jie [University of Wisconsin School of Medicine and Public Health, Medical Physics, Madison, WI (United States); Li, Ke; Chen, Guang-Hong [University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, Departments of Radiology, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, Medical Physics, Madison, WI (United States)

    2015-07-15

    To prospectively compare reduced-dose (RD) CT colonography (CTC) with standard-dose (SD) imaging using several reconstruction algorithms. Following SD supine CTC, 40 patients (mean age, 57.3 years; 17 M/23 F; mean BMI, 27.2) underwent an additional RD supine examination (targeted dose reduction, 70-90 %). DLP, CTDI{sub vol}, effective dose, and SSDE were compared. Several reconstruction algorithms were applied to RD series. SD-FBP served as reference standard. Objective image noise, subjective image quality and polyp conspicuity were assessed. Mean CTDI{sub vol} and effective dose for RD series was 0.89 mGy (median 0.65) and 0.6 mSv (median 0.44), compared with 3.8 mGy (median 3.1) and 2.8 mSv (median 2.3) for SD series, respectively. Mean dose reduction was 78 %. Mean image noise was significantly reduced on RD-PICCS (24.3 ± 19HU) and RD-MBIR (19 ± 18HU) compared with RD-FBP (90 ± 33), RD-ASIR (72 ± 27) and SD-FBP (47 ± 14 HU). 2D image quality score was higher with RD-PICCS, RD-MBIR, and SD-FBP (2.7 ± 0.4/2.8 ± 0.4/2.9 ± 0.6) compared with RD-FBP (1.5 ± 0.4) and RD-ASIR (1.8 ± 0.44). A similar trend was seen with 3D image quality scores. Polyp conspicuity scores were similar between SD-FBP/RD-PICCS/RD-MBIR (3.5 ± 0.6/3.2 ± 0.8/3.3 ± 0.6). Sub-milliSievert CTC performed with iterative reconstruction techniques demonstrate decreased image quality compared to SD, but improved image quality compared to RD images reconstructed with FBP. (orig.)

  12. Towards a framework for analysis of eye-tracking studies in the three dimensional environment: a study of visual search by experienced readers of endoluminal CT colonography.

    Science.gov (United States)

    Helbren, E; Halligan, S; Phillips, P; Boone, D; Fanshawe, T R; Taylor, S A; Manning, D; Gale, A; Altman, D G; Mallett, S

    2014-05-01

    Eye tracking in three dimensions is novel, but established descriptors derived from two-dimensional (2D) studies are not transferable. We aimed to develop metrics suitable for statistical comparison of eye-tracking data obtained from readers of three-dimensional (3D) "virtual" medical imaging, using CT colonography (CTC) as a typical example. Ten experienced radiologists were eye tracked while observing eight 3D endoluminal CTC videos. Subsequently, we developed metrics that described their visual search patterns based on concepts derived from 2D gaze studies. Statistical methods were developed to allow analysis of the metrics. Eye tracking was possible for all readers. Visual dwell on the moving region of interest (ROI) was defined as pursuit of the moving object across multiple frames. Using this concept of pursuit, five categories of metrics were defined that allowed characterization of reader gaze behaviour. These were time to first pursuit, identification and assessment time, pursuit duration, ROI size and pursuit frequency. Additional subcategories allowed us to further characterize visual search between readers in the test population. We propose metrics for the characterization of visual search of 3D moving medical images. These metrics can be used to compare readers' visual search patterns and provide a reproducible framework for the analysis of gaze tracking in the 3D environment. This article describes a novel set of metrics that can be used to describe gaze behaviour when eye tracking readers during interpretation of 3D medical images. These metrics build on those established for 2D eye tracking and are applicable to increasingly common 3D medical image displays.

  13. CT colonography with limited bowel preparation: prospective assessment of patient experience and preference in comparison to optical colonoscopy with cathartic bowel preparation

    NARCIS (Netherlands)

    S. Jensch; S. Bipat; J. Peringa; A.H. de Vries; A. Heutinck; E. Dekker; L.C. Baak; A.D. Montauban van Swijndregt; J. Stoker

    2010-01-01

    The purpose of this study was to prospectively compare participant experience and preference of limited preparation computed tomography colonography (CTC) with full-preparation colonoscopy in a consecutive series of patients at increased risk of colorectal cancer. CTC preparation comprised 180 ml di

  14. Massive-training support vector regression and Gaussian process for false-positive reduction in computer-aided detection of polyps in CT colonography.

    Science.gov (United States)

    Xu, Jian-Wu; Suzuki, Kenji

    2011-04-01

    A massive-training artificial neural network (MTANN) has been developed for the reduction of false positives (FPs) in computer-aided detection (CADe) of polyps in CT colonography (CTC). A major limitation of the MTANN is the long training time. To address this issue, the authors investigated the feasibility of two state-of-the-art regression models, namely, support vector regression (SVR) and Gaussian process regression (GPR) models, in the massive-training framework and developed massive-training SVR (MTSVR) and massive-training GPR (MTGPR) for the reduction of FPs in CADe of polyps. The authors applied SVR and GPR as volume-processing techniques in the distinction of polyps from FP detections in a CTC CADe scheme. Unlike artificial neural networks (ANNs), both SVR and GPR are memory-based methods that store a part of or the entire training data for testing. Therefore, their training is generally fast and they are able to improve the efficiency of the massive-training methodology. Rooted in a maximum margin property, SVR offers excellent generalization ability and robustness to outliers. On the other hand, GPR approaches nonlinear regression from a Bayesian perspective, which produces both the optimal estimated function and the covariance associated with the estimation. Therefore, both SVR and GPR, as the state-of-the-art nonlinear regression models, are able to offer a performance comparable or potentially superior to that of ANN, with highly efficient training. Both MTSVR and MTGPR were trained directly with voxel values from CTC images. A 3D scoring method based on a 3D Gaussian weighting function was applied to the outputs of MTSVR and MTGPR for distinction between polyps and nonpolyps. To test the performance of the proposed models, the authors compared them to the original MTANN in the distinction between actual polyps and various types of FPs in terms of training time reduction and FP reduction performance. The authors' CTC database consisted of 240 CTC

  15. Your Radiologist Explains CT Colonography

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    Full Text Available ... for the exam to be performed with the most accuracy. If you have any questions about the ... go back to work the same day in most cases. Perhaps you might have some concerns about ...

  16. Your Radiologist Explains CT Colonography

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    Full Text Available ... Index A-Z Spotlight October is National Breast Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography ( ... to screen the large intestine or colon for cancer and growths called polyps. This procedure uses low- ...

  17. Your Radiologist Explains CT Colonography

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    Full Text Available ... Resources Professions Site Index A-Z Spotlight September is National Ovarian Cancer Awareness Month September is National Prostate Cancer Awareness Month Recently posted: Medical ...

  18. Your Radiologist Explains CT Colonography

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    Full Text Available ... A-Z Spotlight October is National Breast Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) ... your attention! Spotlight October is National Breast Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) ...

  19. Your Radiologist Explains CT Colonography

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    Full Text Available ... Index A-Z Spotlight September is National Ovarian Cancer Awareness Month September is National Prostate Cancer Awareness Month Recently posted: Magnetoencephalography (MEG) Venous Insufficiency ( ...

  20. Your Radiologist Explains CT Colonography

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    Full Text Available ... Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Spotlight September ... examination. On the day of your exam, your doctor may restrict you to clear fluids and give ...

  1. Your Radiologist Explains CT Colonography

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test that is used to screen the large intestine ...

  2. Your Radiologist Explains CT Colonography

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    Full Text Available ... Index A-Z Spotlight September is National Ovarian Cancer Awareness Month September is National Prostate Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography ( ...

  3. Your Radiologist Explains CT Colonography

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    Full Text Available ... Site Index A-Z Spotlight October is National Breast Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography ( ... and for your attention! Spotlight October is National Breast Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography ( ...

  4. Your Radiologist Explains CT Colonography

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test that is used to screen the large intestine ...

  5. Computed tomography colonography for the practicing radiologist:A review of current recommendations on methodology and clinical indications

    Institute of Scientific and Technical Information of China (English)

    Paola Scalise; Annalisa Mantarro; Francesca Pancrazi; Emanuele Neri

    2016-01-01

    Colorectal cancer(CRC) represents one of the most relevant causes of morbidity and mortality in Western societies. CRC screening is actually based on faecal occult blood testing, and optical colonoscopy still remains the gold standard screening test for cancer detection. However, computed tomography colonography(CT colonography) constitutes a reliable, minimally-invasive method to rapidly and effectively evaluate the entire colon for clinically relevant lesions. Furthermore, even if the benefits of its employment in CRC mass screening have not fully established yet, CT colonography may represent a reasonable alternative screening test in patients who cannot undergo or refuse colonoscopy. Therefore, the purpose of our review is to illustrate the most updated recommendations on methodology and the current clinical indications of CT colonography, according to the data of the existing relevant literature.

  6. Comparative performance of a primary-reader and second-reader paradigm of computer-aided detection for CT colonography in a low-prevalence screening population.

    Science.gov (United States)

    Miyake, Mototaka; Iinuma, Gen; Taylor, Stuart A; Halligan, Steve; Morimoto, Tsuyoshi; Ichikawa, Tamaki; Tomimatsu, Hideto; Beddoe, Gareth; Sugimura, Kazuro; Arai, Yasuaki

    2013-05-01

    To compare the efficacy of computer-aided detection (CAD) for computed tomographic colonography (CTC) when employed as either primary-reader or second-reader paradigms in a low-prevalence screening population. Ninety screening patients underwent same-day CTC and colonoscopy. Four readers prospectively interpreted all CTC data sets using a second-reader paradigm (unassisted interpretation followed immediately by CAD assistance). Three months later, randomized anonymous data sets were re-interpreted by all readers using a primary-reader paradigm (only CAD prompts evaluated). Compared with the average per-patient sensitivity for unassisted interpretation (0.57), both CAD paradigms significantly increased sensitivity: 0.78 (p reader paradigm and 0.83 (p reader paradigm. There was no significant difference between CAD paradigms (p = 0.25). The average per-patient specificity for polyps ≥6 mm was significantly higher using the primary-reader paradigm than the second-reader paradigm (0.90 vs. 0.83, respectively, p = 0.006), with ROC AUCs of 0.83 and 0.68, respectively. Reading time using CAD as a primary-reader paradigm (median 1.4 min) was significantly shorter than both unassisted (median 4.0 min, p reader paradigms (median 5.5 min, p reader paradigm, although the latter may improve specificity and efficiency more.

  7. CT colonography with limited bowel preparation: prospective assessment of patient experience and preference in comparison to optical colonoscopy with cathartic bowel preparation

    Energy Technology Data Exchange (ETDEWEB)

    Jensch, Sebastiaan [University of Amsterdam, Department of Radiology, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Bipat, Shandra; Vries, Ayso H. de; Heutinck, Anneke; Stoker, Jaap [University of Amsterdam, Department of Radiology, Amsterdam (Netherlands); Peringa, Jan; Montauban van Swijndregt, Alexander D. [Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Dekker, Evelien [University of Amsterdam, Department of Gastroenterology and Hepatology, Amsterdam (Netherlands); Baak, Lubbertus C. [Onze Lieve Vrouwe Gasthuis, Department of Gastroenterology, Amsterdam (Netherlands)

    2010-01-15

    The purpose of this study was to prospectively compare participant experience and preference of limited preparation computed tomography colonography (CTC) with full-preparation colonoscopy in a consecutive series of patients at increased risk of colorectal cancer. CTC preparation comprised 180 ml diatrizoate meglumine, 80 ml barium and 30 mg bisacodyl. For the colonoscopy preparation 4 l of polyethylene glycol solution was used. Participants' experience and preference were compared using the Wilcoxon signed rank test and the chi-squared test, respectively. Associations between preference and experience parameters for the 173 participants were determined by logistic regression. Diarrhoea occurred in 94% of participants during CTC preparation. This side effect was perceived as severely or extremely burdensome by 29%. Nonetheless, the total burden was significantly lower for the CTC preparation than for colonoscopy (9% rated the CTC preparation as severely or extremely burdensome compared with 59% for colonoscopy; p<0.001). Participants experienced significantly more pain, discomfort and total burden with the colonoscopy procedure than with CTC (p<0.001). After 5 weeks, 69% preferred CTC, 8% were indifferent and 23% preferred colonoscopy (p<0.001). A burdensome colonoscopy preparation and pain at colonoscopy were associated with CTC preference (p<0.04). In conclusion, participants' experience and preference were rated in favour of CTC with limited bowel preparation compared with full-preparation colonoscopy. (orig.)

  8. Computer-aided detection of colonic polyps with level set-based adaptive convolution in volumetric mucosa to advance CT colonography toward a screening modality

    Science.gov (United States)

    Zhu, Hongbin; Duan, Chaijie; Pickhardt, Perry; Wang, Su; Liang, Zhengrong

    2009-01-01

    As a promising second reader of computed tomographic colonography (CTC) screening, the computer-aided detection (CAD) of colonic polyps has earned fast growing research interest. In this paper, we present a CAD scheme to automatically detect colonic polyps in CTC images. First, a thick colon wall representation, ie, a volumetric mucosa (VM) with several voxels wide in general, was segmented from CTC images by a partial-volume image segmentation algorithm. Based on the VM, we employed a level set-based adaptive convolution method for calculating the first- and second-order spatial derivatives more accurately to start the geometric analysis. Furthermore, to emphasize the correspondence among different layers in the VM, we introduced a middle-layer enhanced integration along the image gradient direction inside the VM to improve the operation of extracting the geometric information, like the principal curvatures. Initial polyp candidates (IPCs) were then determined by thresholding the geometric measurements. Based on IPCs, several features were extracted for each IPC, and fed into a support vector machine to reduce false positives (FPs). The final detections were displayed in a commercial system to provide second opinions for radiologists. The CAD scheme was applied to 26 patient CTC studies with 32 confirmed polyps by both optical and virtual colonoscopies. Compared to our previous work, all the polyps can be detected successfully with less FPs. At the 100% by polyp sensitivity, the new method yielded 3.5 FPs/dataset. PMID:20428331

  9. Comparison of a unidirectional panoramic 3D endoluminal interpretation technique to traditional 2D and bidirectional 3D interpretation techniques at CT colonography: preliminary observations

    Energy Technology Data Exchange (ETDEWEB)

    Lenhart, D.K.; Babb, J.; Bonavita, J.; Kim, D. [Department of Radiology, NYU Medical Center, 560 First Avenue, Suite HW-202, New York, NY 10016 (United States); Bini, E.J. [Department of Medicine, NYU School of Medicine, NYU Medical Center, 560 First Avenue, Suite HW-202, New York, NY 10016 (United States); Megibow, A.J. [Department of Radiology, NYU Medical Center, 560 First Avenue, Suite HW-202, New York, NY 10016 (United States); Macari, M., E-mail: michael.macari@med.nyu.ed [Department of Radiology, NYU Medical Center, 560 First Avenue, Suite HW-202, New York, NY 10016 (United States)

    2010-02-15

    Aim: To compare the evaluation times and accuracy of unidirectional panoramic three-dimensional (3D) endoluminal interpretation to traditional two-dimensional (2D) and bidirectional 3D endoluminal techniques. materials and methods: Sixty-nine patients underwent computed tomography colonography (CTC) after bowel cleansing. Forty-five had no polyps and 24 had at least one polyp >=6 mm. Patients underwent same-day colonoscopy with segmental unblinding. Three experienced abdominal radiologists evaluated the data using one of three primary interpretation techniques: (1) 2D; (2) bidirectional 3D; (3) panoramic 3D. Mixed model analysis of variance and logistic regression for correlated data were used to compare techniques with respect to time and sensitivity and specificity. Results: Mean evaluation times were 8.6, 14.6, and 12.1 min, for 2D, 3D, and panoramic, respectively. 2D was faster than either 3D technique (p < 0.0001), and the panoramic technique was faster than bidirectional 3D (p = 0.0139). The overall sensitivity of each technique per polyp and per patient was 68.4 and 76.7% for 2D, 78.9 and 93.3% for 3D; and 78.9 and 86.7% for panoramic 3D. Conclusion: 2D interpretation was the fastest overall, the panoramic technique was significantly faster than the bidirectional with similar sensitivity and specificity. The sensitivity for a single reader was significantly lower using the 2D technique. Each reader should select the technique with which they are most successful.

  10. Micro-CT辅助结肠造影在小鼠炎性肠病中的应用%Monitoring Colitis Development in Mice by Micro-CT Colonography

    Institute of Scientific and Technical Information of China (English)

    王维刚; 刘震泽; 严惠敏

    2011-01-01

    To evaluate colon wall thickness noninvasively in the dextran sodium sulfate (DSS) induced mouse model of colitis, we performed micro-CT colonography. Mice were scanned by micro-CT at day 0, day 8 and day 13 after induction of colitis and calculated the colon wall thickness. Iopamidol was used by oral and intraperitoneal injection to show the colon wall. The value of the descending colon wall thickness were 0.4586±0.04 mm (day 8) and 0.40325±0.03 mm (day 13) significantly (P<0.001) higher than the control group (0.28±0.02 mm). The related body weight loss, clinical score, histological section and score were consistent with the result of micro-CT. Thus, the results suggested that micro-CT can be used directly, consecutively and noninvasively in monitoring of the inflammatory response in mouse colitis in future studies.%用DSS喂饲小鼠建立小鼠IBD模型,在建模的第0、8、13天分别用碘帕醇灌胃加腹腔注射的方法造影并micro-CT扫描降结肠壁厚度,结果第8天和第13天分别为0.4586±0.04 mm和0.40325±0.03 mm,显著(P<0.001)大于对照组((0.28±0.02 mm).同时检测小鼠体重变化、临床评分、结肠病理切片并评分,发现结肠壁厚度变化趋势和常规指标一致.应用micro-CT辅助小鼠结肠造影方法,可以直观、动态、无创地对小鼠肠道进行影像学分析.

  11. Virtual colonoscopy (CT colonography) in the identification of colorectal cancer. A prospective study in symptomatic patients; Impiego dell'endoscopia virtuale con Tomografia Computerizzata nell'identificazione delle neoplasie colorettali. Studio prospettivo in pazienti sintomatici

    Energy Technology Data Exchange (ETDEWEB)

    Regge, D.; Martincich, L.; Gallo, T.; Pollone, M. [Istituto per la Ricerca e la Cura del Cancro, Ordine Mauriziano, Reparto di Radiologia, Candiolo, TO (Italy); Galatola, G.; Secreto, P.; Pera, A. [Ospedale Mauriziano Umberto, Turin (Italy). Unita' Operativa di Gastroenterologia; Rivolta, A. [Istituto per la Ricerca e la Cura del Cancro, Ordine Mauriziano, Candiolo, TO (Italy). Servizio di Fisica Sanitaria

    2000-06-01

    Aim of this study was to evaluate the sensitivity of virtual colonoscopy (CT colonography) in the identification of colorectal cancer and to define the limitations and the advantages of this imaging modality, as well as indications to the examination. It was examined prospectively 62 symptomatic patients aged 36 to 82 years (28 women and 34 men). All patients underwent both conventional and virtual colonoscopy on the same day; the conventional examination allowed exploration of the entire colon. Conventional colonoscopy identified 89 lesions 3-50 mm in diameter, namely 84 benign and 5 malignant lesions. No lesions were identified in 12 patients. CT colonography identified 52 of the 89 lesions, with 57.1% diagnostic accuracy. They were 11 false positives (82.5% positive predictive value and 52.2% specificity) and 37 false negatives (24.5% negative predictive value and 58.4% sensitivity). Sensitivity was significantly higher (85.7%) for polyps {>=} 1 cm. Virtual colonoscopy is an imaging modality with good diagnostic yield, well tolerated by patients and with great potentials for further development. It was suggested that the examination be performed in symptomatic patients who cannot undergo total colonoscopy or refuse the other imaging modalities. Further studies are warranted in larger series of patients, possibly introducing it in screening programs. [Italian] Scopo di questo lavoro e' valutare la sensibilita' della colonscopia virtuale con TC nell'identificazione delle neoplasie colorettali, definendo gli attuali limiti e vantaggi della metodica e le possibili indicazioni dell'indagine. E' stato condotto uno studio prospettico su 62 pazienti sintomatici con eta' compresa fra 36 e 82 anni di cui 28 donne e 34 uomini. Tutti i pazienti sono stati sottoposti nello stesso giorno sia a colonscopia tradizionale, che in ogni caso ha consentito l'esplorazione di tutto il colon, sia a colonscopia virtuale. Con colonscopia tradizionale

  12. Computer-aided detection (CAD) as a second reader using perspective filet view at CT colonography: effect on performance of inexperienced readers

    Energy Technology Data Exchange (ETDEWEB)

    Fisichella, V.A. [Department of Radiology, Sahlgrenska University Hospital and Sahlgrenska Academy at University of Gothenburg, Gothenburg (Sweden)], E-mail: valeria.fisichella@vgregion.se; Jaederling, F. [Department of Radiology, St. Goeran' s Hospital, Stockholm (Sweden); Horvath, S. [Department of Radiology, Sahlgrenska University Hospital and Sahlgrenska Academy at University of Gothenburg, Gothenburg (Sweden); Stotzer, P.-O.; Kilander, A. [Department of Gastroenterology, Sahlgrenska University Hospital, Gothenburg (Sweden); Bath, M. [Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg (Sweden); Hellstroem, M. [Department of Radiology, Sahlgrenska University Hospital and Sahlgrenska Academy at University of Gothenburg, Gothenburg (Sweden)

    2009-10-15

    Aim: To evaluate whether computer-aided detection (CAD) as a second reader using perspective filet view [three-dimensional (3D) filet] improves the performance of inexperienced readers at computed tomography colonography (CTC) compared with unassisted 3D filet and unassisted two-dimensional (2D) CTC. Material and methods: Fifty symptomatic patients underwent CTC and same-day colonoscopy with segmental unblinding. Two inexperienced readers read the CTC studies on 3D filet and 2D several weeks apart. Four months later, readers re-read the cases only evaluating CAD marks using 3D filet. Suspicious CAD marks not previously described on 3D filet were recorded. Jackknife free-response receiver operating characteristic (JAFROC-1) analysis was used to compare the observers' performances in detecting lesions with 3D filet, 2D and 3D filet with CAD. Results: One hundred and three lesions {>=}3 mm were detected at colonoscopy with segmental unblinding. CAD alone had a sensitivity of 73% (75/103) at a mean false-positive rate per patient of 12.8 in supine and 11.4 in prone. For inexperienced readers sensitivities with 3D filet with CAD were 58% (60/103) and 48% (50/103) with an improvement of 14-16 percentage points (p < 0.05) compared with 2D and of 10-11 percentage points (p < 0.05) compared with 3D filet. For inexperienced readers, the false-positive rate was 25-41% and 71-200% higher with 3D filet with CAD compared with 3D filet and 2D, respectively. JAFROC-1 analysis showed no significant differences in per-lesion overall performance among reading modes (p = 0.8). Conclusion: CAD applied as a second reader using 3D filet increased both sensitivity and the number of false positives by inexperienced readers compared with 3D filet and 2D, thus not improving overall performance, i.e., the ability to distinguish between lesions and non-lesions.

  13. Efficacy of Barium-Based Fecal Tagging for CT Colonography: a Comparison between the Use of High and Low Density Barium Suspensions in a Korean Population - a Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Ju; Park, Seong Ho; Lee, Seung Soo; Byeon, Jeong Sik; Kim, Jung Hoon; Kim, Yeoung Nam; Kim, Ah Young; Ha, Hyun Kwon [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Choi, Eugene K. [University of California Los Angeles, Los Angeles (United States)

    2009-02-15

    This preliminarily study was designed to determine and to compare the efficacy of two commercially available barium-based fecal tagging agents for CT colonography (CTC) (high-density [40% w/v] and low-density [4.6% w/v] barium suspensions) in a population in Korea. In a population with an identified with an average-risk for colorectal cancer, 15 adults were administered three doses of 20 ml 40% w/v barium for fecal tagging (group I) and 15 adults were administered three doses of 200 ml 4.6% w/v barium (group II) for fecal tagging. Excluding five patients in group I and one patient in group II that left the study, ten patients in group I and 14 patients in group II were finally included in the analysis. Two experienced readers evaluated the CTC images in consensus regarding the degree of tagging of stool pieces 6 mm or larger. Stool pieces were confirmed with the use of standardized CTC criteria or the absence of matched lesions as seen on colonoscopy. The rates of complete fecal tagging were analyzed on a per-lesion and a per-segment basis and were compared between the patients in the two groups. Per-lesion rates of complete fecal tagging were 52% (22 of 42; 95% CI, 37.7-66.6%) in group I and 78% (28 of 36; 95% CI, 61.7-88.5%) in group II. The difference between the two groups did not reach statistical significance (p = 0.285). The per-segment rates of complete tagging were 33% (6 of 18; 95% CI, 16.1%-56.4%) in group I and 60% (9 of 15; 95% CI, 35.7%-80.3%) in group II; again, the difference between the two groups did not reach statistical significance (p = 0.171). Barium-based fecal tagging using both the 40% w/v and the 4.6% w/v barium suspensions showed moderate tagging efficacy. The preliminary comparison did not demonstrate a statistically significant difference in the tagging efficacy between the use of the two tagging agents, despite the tendency toward better tagging with the use of the 4.6% w/v barium suspension.

  14. The Danish randomized lung cancer CT screening trial

    DEFF Research Database (Denmark)

    Pedersen, Jesper H; Ashraf, Haseem; Dirksen, Asger

    2009-01-01

    INTRODUCTION: Lung cancer screening with low dose computed tomography (CT) has not yet been evaluated in randomized clinical trials, although several are underway. METHODS: In The Danish Lung Cancer Screening Trial, 4104 smokers and previous smokers from 2004 to 2006 were randomized to either...... lung cancer. Ten of these had stage I disease. Eleven of 17 lung cancers at baseline were treated surgically, eight of these by video assisted thoracic surgery resection. CONCLUSIONS: Screening may facilitate minimal invasive treatment and can be performed with a relatively low rate of false......-positive screen results compared with previous studies on lung cancer screening....

  15. The feasibility study of low-dose gem energy spectrum CT colonography in the diagnosis of colonic polyps%低剂量宝石能谱 CT 结肠成像在检测结肠息肉中的可行性研究

    Institute of Scientific and Technical Information of China (English)

    李家言; 黄乔统; 何欣; 黄增超; 刘熙荣; 廖海; 袁文昭; 张锡流; 袁捷; 韦兰珍

    2014-01-01

    Objective To explore the feasibility of low doses of gem energy spectrum CT colonography ( CTC) in detecting polyps of the colon .Methods A total of 50 patients with suspected colonic polyps underwent low-dose gem energy spectrum CTC and endoscopy .The colonic polyps were observed by endoscopy and gem energy spectrum CTC,with the endoscopic finding as gold standard .The coincidence was evaluated for colonic polyps by the gem energy spectrum CTC ,and calculated CT dose index ( CTDIw) in prone was recorded .Results Thirty-eight pa-tients were diagnosed to have colonic polyps by endoscopy and 12 were negative ,the CTC negative diagnosis of colonic polyps in 16 cases and positive 34 cases.Total 79 polyps in 50 patients were found by CTC .For polyp size≥0.5 cm and <0.5 cm, the compliance was 91.07%, and 50.00%,respectively.Conclusion Reduction of the effective dose to 1.01 mGy significantly affects images quality on gemstone energy spectrum CTC ,but the perception of ≥0.5 cm lesion not significantly impaired .%目的:探讨低剂量宝石能谱CT结肠成像( CTC)在检测结肠息肉中的可行性。方法对50例疑似结肠息肉患者行低剂量宝石能谱CTC及内镜检查,以内镜结果作为金标准,计算低剂量宝石能谱CTC检测结肠息肉的符合率,并记录扫描的CT剂量指数( CTDIw )。结果内镜诊断结肠息肉阴性12例,阳性38例;低剂量宝石能谱CTC诊断结肠息肉阴性16例,阳性34例;共发现79个息肉。对于≥0.5 cm的息肉,低剂量宝石能谱CTC的符合率为91.07%,<5 mm的息肉符合率为50%。结论辐射剂量降低至1.01 mGy的宝石能谱CTC检测≥0.5 cm的息肉,与内镜有较高的符合率。

  16. Ultrasound colonography in visualization of large intestine cancer pathology

    Directory of Open Access Journals (Sweden)

    N. V. Tumanskaya

    2013-08-01

    Full Text Available Introduction: colon oncopathology takes the 2-nd place among different kinds of cancer and tends to grow constantly. Thus, the incidence of colorectal cancer (CRC in Ukraine is 20.6 cases per 100 thousands of population. 70-75% of patients are diagnosed only at the 3-4 stage of the disease, due to its long asymptomatic initial period. The gold standard of diagnostic of CRC is endoscopy, which enables not only to visualize altered intestinal mucosa, but also to perform a biopsy for morphological study. Modern imaging diagnostic methods (virtual CT colonography, MRI, PET / CT, which are used in developed countries, are not been widely spreded in Ukraine, unfortunately. Complex ultrasound examination reveals new diagnostic capabilities in the solution of this problem. Ultrasound colonography allows morphology assessing of all parts of the large intestine. This method is primarily justified for those patients who can’t be examined with conventional irrigoscopy and endoscopic colonoscopy because of some objective reasons. Objectives of the research: to objectify the diagnostic capabilities of ultrasound colonography as an alternative method of imaging of colorectal cancer. Matherials and methods: The colonography was performed with the ultrasound scanner HD11 (Philips in 26 patients with clinically suspected large intestine pathology. There were 10 male and 16 female patients with the average age 55,3±9,2. All patients were performed X-ray multislice computed tomography (MSCT as the reference method. 9 patients were operated on with the followed morphological analysis of affected parts of the intestine. Results and discussion: the colon pathology in our research was found in 10 patients (38.5% of the patients. Among them stenotic form of colorectal cancer was diagnosed in 6 patients (22.8%. In 4 patients (15.2% the polypoid form of colorectal cancer was found. In both cases, the affected area was located in the region of rectosigmoid junction. In

  17. Virtual reality in MR-colonography; Die virtuelle Realitaet der MR-Kolonographie

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfelder, D.; Debatin, J.F. [Zentralinstitut fuer Roentgendiagnostik, Universitaetsklinikum Essen (Germany)

    2000-03-01

    Early detection and subsequent removal of colorectal polyps have been shown to constitute an effective approach for decreasing the incidence of colorectal cancer. The lack of an ideal modality for colorectal polyp screening stimulated interest in the development of CT-colonography and MR-colonography. Both techniques allow the colon to be analyzed in a cross-sectional as well as a virtual endoscopic format. Causing no side-effects and not concerning for radiation exposure MR-colonography warrants further consideration. Additional to detecting polyps down to 6 mm in size the inner wall contour and the morphology of the colonic wall itself can be assessed. New developments like fecal tagging will increase patients acceptance comparing to other diagnostic techniques. In search of an ideal modality for polyp screening MR-colonography will become a potent option in the diagnostic arsenal. (orig.) [German] Die fruehzeitige Entdeckung und Entfernung eines Polypen kann das Risiko fuer die Entwicklung eines kolorektalen Karzinoms entscheidend reduzieren. Das bisherige Fehlen einer geeigneten Vorsorgeuntersuchung eroeffnet hier Moeglichkeiten fuer die Entwicklung der CT- und MR-Kolonographie. Beide Techniken erlauben die selektive Darstellung des Kolons - Kolonographie - sowie die Simulation einer endoskopischen Untersuchung - virtuelle Koloskopie. Insbesondere die nebenwirkungsfreie und ohne Strahlenbelastung durchzufuehrende MR-Kolonographie verdient hier besonderes Augenmerk. Zusaetzlich zur Detektion von Polypen bis hin zu 6 mm Groesse kann anhand der Schnittbilder eine Beurteilung der Koloninnenwand erfolgen und auch die Morphologie der Kolonwand kann beurteilt werden. Neue Entwicklungen in der MR-Kolonographie - wie etwa das fecal tagging - werden eine Verbesserung der Patientenakzeptanz im Vergleich zu anderen Untersuchungstechniken ermoeglichen. Auf der Suche nach der optimalen Vorsorgeuntersuchung zum Nachweis kolorektaler Polypen zeigt die MR-Kolonographie einen

  18. 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...... from being referred to 'early SPC'. DanPaCT is a multicenter, parallel-group, superiority clinical trial with 1:1 randomization. The planned sample size was 300 patients. The primary data collection for DanPaCT is finished. To prevent outcome reporting bias, selective reporting, and data-driven results...... data, multiplicity and the risk of bias. CONCLUSIONS: Only few trials have investigated the effects of SPC. To our knowledge DanPaCT is the first trial to investigate screening based 'early SPC' for patients with metastatic cancer from a broad spectrum of cancer diagnosis. TRIAL REGISTRATION...

  19. Feasibility study of computed tomography colonography using limited bowel preparation at normal and low-dose levels study

    Energy Technology Data Exchange (ETDEWEB)

    Florie, Jasper; Gelder, Rogier E. van; Schutter, Michiel P.; Randen, Adrienne van; Jager, Steven de; Prent, Anna; Bipat, Shandra [Academic Medical Center, Department of Radiology, G1-230, P.O. Box 22660, Amsterdam (Netherlands); Venema, Henk W. [Academic Medical Center, Department of MedicaPhysics, L0-106, P.O. Box 22660, Amsterdam (Netherlands); Hulst, Victor P.M. van der [Onze Lieve Vrouwe Gasthuis, Department of Radiology, P.O. BOX 95500, Amsterdam (Netherlands); Bossuyt, Patrick M.M. [Academic Medical Center, Department Clinical Epidemiology and Biostatistics, J1b-212, P.O. BOX 22660, Amsterdam (Netherlands); Baak, Lubbertus C. [Onze Lieve Vrouwe Gasthuis, Department Gastroenterology, P.O. BOX 95500, Amsterdam (Netherlands); Stoker, Jaap [Academic Medical Center, Department of Radiology, G1-211, P.O. BOX 22660, Amsterdam (Netherlands)

    2007-12-15

    The purpose was to evaluate low-dose CT colonography without cathartic cleansing in terms of image quality, polyp visualization and patient acceptance. Sixty-one patients scheduled for colonoscopy started a low-fiber diet, lactulose and amidotrizoic-acid for fecal tagging 2 days prior to the CT scan (standard dose, 5.8-8.2 mSv). The original raw data of 51 patients were modified and reconstructed at simulated 2.3 and 0.7 mSv levels. Two observers evaluated the standard dose scan regarding image quality and polyps. A third evaluated the presence of polyps at all three mSv levels in a blinded prospective way. All observers were blinded to the reference standard: colonoscopy. At three times patients were given questionnaires relating to their experiences and preference. Image quality was sufficient in all patients, but significantly lower in the cecum, sigmoid and rectum. The two observers correctly identified respectively 10/15 (67%) and 9/15 (60%) polyps {>=}10 mm, with 5 and 8 false-positive lesions (standard dose scan). Dose reduction down to 0.7 mSv was not associated with significant changes in diagnostic value (polyps {>=}10 mm). Eighty percent of patients preferred CT colonography and 13% preferred colonoscopy (P<0.001). CT colonography without cleansing is preferred to colonoscopy and shows sufficient image quality and moderate sensitivity, without impaired diagnostic value at dose-levels as low as 0.7 mSv. (orig.)

  20. Time-efficient CT colonography interpretation using an advanced image-gallery-based, computer-aided ''first-reader'' workflow for the detection of colorectal adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Mang, Thomas; Ringl, Helmut; Weber, Michael; Mueller-Mang, Christina [Medical University of Vienna, Department of Radiology, Vienna (Austria); Hermosillo, Gerardo; Wolf, Matthias; Bogoni, Luca; Salganicoff, Marcos; Raykar, Vikas [Siemens Healthcare, Siemens Medical Solutions, H IM SY CAD R and D, Malvern, PA (United States); Graser, Anno [University of Munich - Grosshadern Campus, Department of Clinical Radiology, Munich (Germany)

    2012-12-15

    To assess the performance of an advanced ''first-reader'' workflow for computer-aided detection (CAD) of colorectal adenomas {>=} 6 mm at computed tomographic colonography (CTC) in a low-prevalence cohort. A total of 616 colonoscopy-validated CTC patient-datasets were retrospectively reviewed by a radiologist using a ''first-reader'' CAD workflow. CAD detections were presented as galleries of six automatically generated two-dimensional (2D) and three-dimensional (3D) images together with interactive 3D target views and 2D multiplanar views of the complete dataset. Each patient-dataset was interpreted by initially using CAD image-galleries followed by a fast 2D review to address unprompted colonic areas. Per-patient, per-polyp, and per-adenoma sensitivities were calculated for lesions {>=} 6 mm. Statistical testing employed Fisher's exact and McNemar tests. In 91/616 patients, 131 polyps (92 adenomas, 39 non-adenomas) {>=} 6 mm and two cancers were identified by reference standard. Using the CAD gallery-based first-reader workflow, the radiologist detected all adenomas {>=} 10 mm (34/34) and cancers. Per-patient and polyp sensitivities for lesions {>=} 6 mm were 84.3 % (75/89), and 83.2 % (109/131), respectively, with 89.1 % (57/64) and 85.9 % (79/92) for adenomas. Overall specificity was 95.6 % (504/527). Mean interpretation time was 3.1 min per patient. A CAD algorithm, applied in an image-gallery-based first-reader workflow, can substantially decrease reading times while enabling accurate detection of colorectal adenomas in a low-prevalence population. (orig.)

  1. Irritable bowel syndrome evaluation using computed tomography colonography.

    Science.gov (United States)

    Ohgo, Hideki; Imaeda, Hiroyuki; Yamaoka, Minoru; Yoneno, Kazuaki; Hosoe, Naoki; Mizukami, Takeshi; Nakamoto, Hidetomo

    2016-11-14

    To evaluate the morphology of the colon in patients with irritable bowel syndrome (IBS) by using computed tomography colonography (CTC). Twelve patients with diarrhea type IBS (IBS-D), 13 patients with constipation type IBS (IBS-C), 12 patients with functional constipation (FC) and 14 control patients underwent colonoscopy following CTC. The lengths of the rectosigmoid colon, transverse colon and the total colon were measured. The diameters of the rectum, sigmoid colon, descending colon, transverse colon, and ascending colon were measured. The mean length of the total colon was 156.5 cm in group C, 158.9 cm in group IBS-D, 172.0 cm in group IBS-C, and 188.8 cm in group FC. The total colon in group FC was significantly longer than that in group C (P colon was 56.2 cm, 55.9 cm, 63.6cm, and 77.4 cm (NS). The mean length of the transverse colon was 49.9 cm, 43.1 cm, 57.0 cm, and 55.0 cm. The transverse colon in group IBS-D was significantly shorter than that in group IBS-C (P colon was 4.0 cm, 3.3 cm, 4.2 cm, and 4.3 cm (NS). The mean diameter of the descending colon was 3.6 cm, 3.1 cm, 3.8 cm, and 4.3 cm. The descending colon diameter in group IBS-D was significantly less than that in group IBS-C (P = 0.03) and that in group FC (P colon diameter in group FC was significantly greater than that in group C (P = 0.04). The mean diameter of the transverse colon was 4.4 cm, 3.3 cm, 4.2 cm, and 5.0 cm (NS). CT colonography might contribute the clarification of subtypes of IBS.

  2. Healthcare costs in the Danish randomised controlled lung cancer CT-screening trial

    DEFF Research Database (Denmark)

    Rasmussen, J.F.; Siersma, V.; Pedersen, Jesper H.;

    2014-01-01

    OBJECTIVES: Low dose computerised tomography (CT) screening for lung cancer can reduce lung-cancer-specific mortality. The objective of this study was to analyse healthcare costs and healthcare utilisation of participants in the Danish lung cancer CT-screening trial (DLCST). MATERIALS AND METHODS...

  3. Contamination during 4 years of annual CT screening in the Danish Lung Cancer Screening Trial (DLCST)

    DEFF Research Database (Denmark)

    Saghir, Zaigham; Ashraf, Haseem; Dirksen, Asger

    2010-01-01

    Contamination, defined as screening in the control arm, may dilute the statistical power of randomised screening trials. We investigated the rate of contamination in DLCST during 4 years of annual CT screening.......Contamination, defined as screening in the control arm, may dilute the statistical power of randomised screening trials. We investigated the rate of contamination in DLCST during 4 years of annual CT screening....

  4. Computed tomographic colonography:Hope or hype?

    Institute of Scientific and Technical Information of China (English)

    Otto; Schiueh-Tzang; Lin

    2010-01-01

    Computed tomographic colonography (CTC) is a promising emerging technology for imaging of the colon. This concise review discusses the currently available data on CTC technique,test characteristics,acceptance,safety,cost-effectiveness,follow-up strategy,and extracolonic findings. In summary,CTC technique is still evolving,and further research is needed to clarify the role of automated colonic insufflation,smooth-muscle relaxants,intravenous and oral contrast,soft-ware rendering,and patient positioning. Curr...

  5. 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...... from being referred to 'early SPC'. DanPaCT is a multicenter, parallel-group, superiority clinical trial with 1:1 randomization. The planned sample size was 300 patients. The primary data collection for DanPaCT is finished. To prevent outcome reporting bias, selective reporting, and data-driven results......-individualised outcome representing the score of the symptom or problem that had the highest intensity out of seven at baseline assessed with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). Secondary outcomes are the seven scales that are represented...

  6. Monitoring of Tumor Promotion and Progression in a Mouse Model of Inflammation-Induced Colon Cancer with Magnetic Resonance Colonography

    Directory of Open Access Journals (Sweden)

    Matthew R. Young

    2009-03-01

    Full Text Available Early detection of precancerous tissue has significantly improved survival of most cancers including colorectal cancer (CRC. Animal models designed to study the early stages of cancer are valuable for identifying molecular events and response indicators that correlate with the onset of disease. The goal of this work was to investigate magnetic resonance (MR colonography in a mouse model of CRC on a clinical MR imager. Mice treated with azoxymethane and dextran sulfate sodium were imaged by serial MR colonography (MRC from initiation to euthanasia. Magnetic resonance colonography was obtained with both T1- and T2-weighted images after administration of a Fluorinert enema to remove residual luminal signal and intravenous contrast to enhance the colon wall. Individual tumor volumes were calculated and validated ex vivo. The Fluorinert enema provided a clear differentiation of the lumen of the colon from the mucosal lining. Inflammation was detected 3 days after dextran sulfate sodium exposure and subsided during the next week. Tumors as small as 1.2 mm3 were detected and as early as 29 days after initiation. Individual tumor growths were followed over time, and tumor volumes were measured by MR imaging correlated with volumes measured ex vivo. The use of a Fluorinert enema during MRC in mice is critical for differentiating mural processes from intraluminal debris. Magnetic resonance colonography with Fluorinert enema and intravenous contrast enhancement will be useful in the study of the initial stages of colon cancer and will reduce the number of animals needed for preclinical trials of prevention or intervention.

  7. Potential pitfalls in the anorectal region during CT colonography: A ...

    African Journals Online (AJOL)

    2017-02-28

    Feb 28, 2017 ... the balloon in the prone view: (1) to obtain a full scan series without an inflated balloon, to ... a 360° fly around the rectal catheter to ensure adequate ... from a sessile polyp.16 On 2D views, foci of air may be present.

  8. WE-B-207-02: CT Lung Cancer Screening and the Medical Physicist: A Dosimetry Summary of CT Participants in the National Lung Cancer Screening Trial (NLST)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C. [National Cancer Institute (United States)

    2015-06-15

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  9. A multicenter, randomized controlled trial of immediate total-body CT scanning in trauma patients (REACT-2

    Directory of Open Access Journals (Sweden)

    Sierink Joanne C

    2012-03-01

    Full Text Available Abstract Background Computed tomography (CT scanning has become essential in the early diagnostic phase of trauma care because of its high diagnostic accuracy. The introduction of multi-slice CT scanners and infrastructural improvements made total-body CT scanning technically feasible and its usage is currently becoming common practice in several trauma centers. However, literature provides limited evidence whether immediate total-body CT leads to better clinical outcome then conventional radiographic imaging supplemented with selective CT scanning in trauma patients. The aim of the REACT-2 trial is to determine the value of immediate total-body CT scanning in trauma patients. Methods/design The REACT-2 trial is an international, multicenter randomized clinical trial. All participating trauma centers have a multi-slice CT scanner located in the trauma room or at the Emergency Department (ED. All adult, non-pregnant, severely injured trauma patients according to predefined criteria will be included. Patients in whom direct scanning will hamper necessary cardiopulmonary resuscitation or who require an immediate operation because of imminent death (both as judged by the trauma team leader are excluded. Randomization will be computer assisted. The intervention group will receive a contrast-enhanced total-body CT scan (head to pelvis during the primary survey. The control group will be evaluated according to local conventional trauma imaging protocols (based on ATLS guidelines supplemented with selective CT scanning. Primary outcome will be in-hospital mortality. Secondary outcomes are differences in mortality and morbidity during the first year post trauma, several trauma work-up time intervals, radiation exposure, general health and quality of life at 6 and 12 months post trauma and cost-effectiveness. Discussion The REACT-2 trial is a multicenter randomized clinical trial that will provide evidence on the value of immediate total-body CT scanning

  10. Precision Medicine for Advanced Pancreas Cancer: The Individualized Molecular Pancreatic Cancer Therapy (IMPaCT) Trial.

    Science.gov (United States)

    Chantrill, Lorraine A; Nagrial, Adnan M; Watson, Clare; Johns, Amber L; Martyn-Smith, Mona; Simpson, Skye; Mead, Scott; Jones, Marc D; Samra, Jaswinder S; Gill, Anthony J; Watson, Nicole; Chin, Venessa T; Humphris, Jeremy L; Chou, Angela; Brown, Belinda; Morey, Adrienne; Pajic, Marina; Grimmond, Sean M; Chang, David K; Thomas, David; Sebastian, Lucille; Sjoquist, Katrin; Yip, Sonia; Pavlakis, Nick; Asghari, Ray; Harvey, Sandra; Grimison, Peter; Simes, John; Biankin, Andrew V

    2015-05-01

    Personalized medicine strategies using genomic profiling are particularly pertinent for pancreas cancer. The Individualized Molecular Pancreatic Cancer Therapy (IMPaCT) trial was initially designed to exploit results from genome sequencing of pancreatic cancer under the auspices of the International Cancer Genome Consortium (ICGC) in Australia. Sequencing revealed small subsets of patients with aberrations in their tumor genome that could be targeted with currently available therapies. The pilot stage of the IMPaCT trial assessed the feasibility of acquiring suitable tumor specimens for molecular analysis and returning high-quality actionable genomic data within a clinically acceptable timeframe. We screened for three molecular targets: HER2 amplification; KRAS wild-type; and mutations in DNA damage repair pathways (BRCA1, BRCA2, PALB2, ATM). Tumor biopsy and archived tumor samples were collected from 93 patients and 76 were screened. To date 22 candidate cases have been identified: 14 KRAS wild-type, 5 cases of HER2 amplification, 2 mutations in BRCA2, and 1 ATM mutation. Median time from consent to the return of validated results was 21.5 days. An inability to obtain a biopsy or insufficient tumor content in the available specimen were common reasons for patient exclusion from molecular analysis while deteriorating performance status prohibited a number of patients from proceeding in the study. Documenting the feasibility of acquiring and screening biospecimens for actionable molecular targets in real time will aid other groups embarking on similar trials. Key elements include the need to better prescreen patients, screen more patients, and offer more attractive clinical trial options. ©2015 American Association for Cancer Research.

  11. Computer-aided teniae coli detection using height maps from computed tomographic colonography images

    Science.gov (United States)

    Wei, Zhuoshi; Yao, Jianhua; Wang, Shijun; Summers, Ronald M.

    2011-03-01

    Computed tomographic colonography (CTC) is a minimally invasive technique for colonic polyps and cancer screening. Teniae coli are three bands of longitudinal smooth muscle on the colon surface. They are parallel, equally distributed on the colon wall, and form a triple helix structure from the appendix to the sigmoid colon. Because of their characteristics, teniae coli are important anatomical meaningful landmarks on human colon. This paper proposes a novel method for teniae coli detection on CT colonography. We first unfold the three-dimensional (3D) colon using a reversible projection technique and compute the two-dimensional (2D) height map of the unfolded colon. The height map records the elevation of colon surface relative to the unfolding plane, where haustral folds corresponding to high elevation points and teniae to low elevation points. The teniae coli are detected on the height map and then projected back to the 3D colon. Since teniae are located where the haustral folds meet, we break down the problem by first detecting haustral folds. We apply 2D Gabor filter banks to extract fold features. The maximum response of the filter banks is then selected as the feature image. The fold centers are then identified based on piecewise thresholding on the feature image. Connecting the fold centers yields a path of the folds. Teniae coli are finally extracted as lines running between the fold paths. Experiments were carried out on 7 cases. The proposed method yielded a promising result with an average normalized RMSE of 5.66% and standard deviation of 4.79% of the circumference of the colon.

  12. SIMulation of Medication Error induced by Clinical Trial drug labeling: the SIMME-CT study.

    Science.gov (United States)

    Dollinger, Cecile; Schwiertz, Vérane; Sarfati, Laura; Gourc-Berthod, Chloé; Guédat, Marie-Gabrielle; Alloux, Céline; Vantard, Nicolas; Gauthier, Noémie; He, Sophie; Kiouris, Elena; Caffin, Anne-Gaelle; Bernard, Delphine; Ranchon, Florence; Rioufol, Catherine

    2016-06-01

    To assess the impact of investigational drug labels on the risk of medication error in drug dispensing. A simulation-based learning program focusing on investigational drug dispensing was conducted. The study was undertaken in an Investigational Drugs Dispensing Unit of a University Hospital of Lyon, France. Sixty-three pharmacy workers (pharmacists, residents, technicians or students) were enrolled. Ten risk factors were selected concerning label information or the risk of confusion with another clinical trial. Each risk factor was scored independently out of 5: the higher the score, the greater the risk of error. From 400 labels analyzed, two groups were selected for the dispensing simulation: 27 labels with high risk (score ≥3) and 27 with low risk (score ≤2). Each question in the learning program was displayed as a simulated clinical trial prescription. Medication error was defined as at least one erroneous answer (i.e. error in drug dispensing). For each question, response times were collected. High-risk investigational drug labels correlated with medication error and slower response time. Error rates were significantly 5.5-fold higher for high-risk series. Error frequency was not significantly affected by occupational category or experience in clinical trials. SIMME-CT is the first simulation-based learning tool to focus on investigational drug labels as a risk factor for medication error. SIMME-CT was also used as a training tool for staff involved in clinical research, to develop medication error risk awareness and to validate competence in continuing medical education. © The Author 2016. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.

  13. Combined 18F-Fluoride and 18F-FDG PET/CT Scanning for Evaluation of Malignancy: Results of an International Multicenter Trial

    DEFF Research Database (Denmark)

    Iagaru, Andrei; Mittra, Erik; Mosci, Camila;

    2012-01-01

    -FDG PET/CT. The 3 PET/CT scans were performed sequentially within 4 wk of one another for each patient. Results: 18F2/18FFDG PET/CT allowed for accurate interpretation of radiotracer uptake outside the skeleton, with findings similar to those of 18F-FDG PET/CT. In 19 participants, skeletal disease...... was more extensive on 18F2 PET/CT and 18F2/18F-FDG PET/CT than on 18F-FDG PET/CT. In another 29 participants, 18F2 PET/CT and 18F2/18F-FDG PET/CT showed osseous metastases where 18FFDG PET/CT was negative. The extent of skeletal lesions was similar in 18 participants on all 3 scans. Conclusion: This trial...

  14. Change descriptors for determining nodule malignancy in national lung screening trial CT screening images

    Science.gov (United States)

    Geiger, Benjamin; Hawkins, Samuel; Hall, Lawrence O.; Goldgof, Dmitry B.; Balagurunathan, Yoganand; Gatenby, Robert A.; Gillies, Robert J.

    2016-03-01

    Pulmonary nodules are effectively diagnosed in CT scans, but determining their malignancy has been a challenge. The rate of change of the volume of a pulmonary nodule is known to be a prognostic factor for cancer development. In this study, we propose that other changes in imaging characteristics are similarly informative. We examined the combination of image features across multiple CT scans, taken from the National Lung Screening Trial, with individual scans of the same patient separated by approximately one year. By subtracting the values of existing features in multiple scans for the same patient, we were able to improve the ability of existing classification algorithms to determine whether a nodule will become malignant. We trained each classifier on 83 nodules determined to be malignant by biopsy and 172 nodules determined to be benign by their clinical stability through two years of no change; classifiers were tested on 77 malignant and 144 benign nodules, using a set of features that in a test-retest experiment were shown to be stable. An accuracy of 83.71% and AUC of 0.814 were achieved with the Random Forests classifier on a subset of features determined to be stable via test-retest reproducibility analysis, further reduced with the Correlation-based Feature Selection algorithm.

  15. Common findings and pseudolesions at computed tomography colonography: pictorial essay

    OpenAIRE

    Augusto Castelli von Atzingen; Dario Ariel Tiferes; Carlos Alberto Matsumoto; Thiago Franchi Nunes; Marcos Vinicius Alvim Soares Maia; Giuseppe D'Ippolito

    2012-01-01

    Computed tomography colonography is a minimally invasive method for screening for polyps and colorectal cancer, with extremely unusual complications, increasingly used in the clinical practice. In the last decade, developments in bowel preparation, imaging, and in the training of investigators have determined a significant increase in the method sensitivity. Images interpretation is accomplished through a combined analysis of two-dimensional source images and several types of three-dimensiona...

  16. Understanding the Canadian adult CT head rule trial: use of the theoretical domains framework for process evaluation

    Directory of Open Access Journals (Sweden)

    Curran Janet A

    2013-02-01

    Full Text Available Abstract Background The Canadian CT Head Rule was prospectively derived and validated to assist clinicians with diagnostic decision-making regarding the use of computed tomography (CT in adult patients with minor head injury. A recent intervention trial failed to demonstrate a decrease in the rate of head CTs following implementation of the rule in Canadian emergency departments. Yet, the same intervention, which included a one-hour educational session and reminders at the point of requisition, was successful in reducing cervical spine imaging rates in the same emergency departments. The reason for the varied effect of the intervention across these two behaviours is unclear. There is an increasing appreciation for the use of theory to conduct process evaluations to better understand how strategies are linked with outcomes in implementation trials. The Theoretical Domains Framework (TDF has been used to explore health professional behaviour and to design behaviour change interventions but, to date, has not been used to guide a theory-based process evaluation. In this proof of concept study, we explored whether the TDF could be used to guide a retrospective process evaluation to better understand emergency physicians’ responses to the interventions employed in the Canadian CT Head Rule trial. Methods A semi-structured interview guide, based on the 12 domains from the TDF, was used to conduct telephone interviews with project leads and physician participants from the intervention sites in the Canadian CT Head Rule trial. Two reviewers independently coded the anonymised interview transcripts using the TDF as a coding framework. Relevant domains were identified by: the presence of conflicting beliefs within a domain; the frequency of beliefs; and the likely strength of the impact of a belief on the behaviour. Results Eight physicians from four of the intervention sites in the Canadian CT Head Rule trial participated in the interviews. Barriers

  17. Central image archiving and managements system for multicenter clinical studies: Lessons from low-dose CT for appendicitis trial

    Energy Technology Data Exchange (ETDEWEB)

    Ko, You Sun; Lee, Kyong Joon; Lee, Kyoung Ho [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); and others

    2017-03-15

    This special report aimed to document our experiences in implementing the Central Imaging Archiving and Management System (CIAMS) for a multicenter clinical trial, Low-dose CT for Appendicitis Trial (LOCAT), supported by the Korean Society of Radiology and Radiology Imaging Network of Korea for Clinical Research. LOCAT was a randomized controlled trial to determine whether low-dose CT is non-inferior to standard-dose CT with respect to the negative appendectomy rate in patients aged from 15 to 44 years. Site investigators downloaded the CT images from the site picture archiving and communication system servers, and uploaded the anonymized images to the primary server. CIAMS administrators inspected the images routed to the secondary server by a cross-check against image submission worksheets provided by the site investigators. The secondary server was automatically synchronized to the tertiary backup server. Up to June 2016, 2715 patients from 20 sites participated in LOCAT for 30 months. A total of 2539 patients' images (93.5%, 2539/2715) were uploaded to the primary server, 2193 patients' worksheets (80.8%, 2193/2715) were submitted, and 2163 patients' data (79.7%, 2163/2715) were finally monitored. No data error occurred.

  18. The utility of flexible sigmoidoscopy after a computerized tomographic colonography revealing only rectosigmoid lesions.

    Science.gov (United States)

    Young, P E; Gentry, A B; Cash, B D

    2008-03-15

    Identifying polyps by computerized tomographic colonography typically prompts colonoscopy, increasing its cost, risk and inconvenience. Many polyps are confined to the rectosigmoid and theoretically amenable to resection via flexible sigmoidoscopy. To determine the prevalence of advanced proximal colonic neoplasia when computerized tomographic colonography reveals only rectosigmoid polyps, and characterize the yield of polypectomy via flexible sigmoidoscopy in such patients. Subjects underwent computerized tomographic colonography and colonoscopy with segmental unblinding. Patients with only rectosigmoid findings by computerized tomographic colonography were identified retrospectively. Flexible sigmoidoscopy findings were estimated by including lesions distal to the descending/sigmoid colon junction during colonoscopy. Proximal lesions were also reviewed. Advanced lesions were defined as: adenocarcinoma, tubular adenoma >1 cm, > or =3 tubular adenomas, tubulovillous histology or high-grade dysplasia. By computerized tomographic colonography, 15% (203 of 1372) had only rectosigmoid polyps. Concomitant lesions in the proximal colon were seen in 32% (64 of 203) during colonoscopy. Advanced proximal neoplasia occurred in 2% (three of 203) with only rectosigmoid polyps on computerized tomographic colonography. Using flexible sigmoidoscopy to follow-up computerized tomographic colonography demonstrating only rectosigmoid polyps would eliminate 15% of subsequent colonoscopies. This strategy carries a small risk of missed proximal advanced neoplasia. This miss rate appears comparable to that of colonoscopy alone. Further study on the cost-effectiveness of this approach is warranted.

  19. Augmented reality system for CT-guided interventions: system description and initial phantom trials

    Science.gov (United States)

    Sauer, Frank; Schoepf, Uwe J.; Khamene, Ali; Vogt, Sebastian; Das, Marco; Silverman, Stuart G.

    2003-05-01

    We are developing an augmented reality (AR) image guidance system, in which information derived from medical images is overlaid onto a video view of the patient. The interventionalist wears a head-mounted display (HMD) that presents him with the augmented stereo view. The HMD is custom fitted with two miniature color video cameras that capture the stereo view of the scene. A third video camera, operating in the near IR, is also attached to the HMD and is used for head tracking. The system achieves real-time performance of 30 frames per second. The graphics appears firmly anchored in the scne, without any noticeable swimming or jitter or time lag. For the application of CT-guided interventions, we extended our original prototype system to include tracking of a biopsy needle to which we attached a set of optical markers. The AR visualization provides very intuitive guidance for planning and placement of the needle and reduces radiation to patient and radiologist. We used an interventional abdominal phantom with simulated liver lesions to perform an inital set of experiments. The users were consistently able to locate the target lesion with the first needle pass. These results provide encouragement to move the system towards clinical trials.

  20. The impact of radiologists' expertise on screen results decisions in a CT lung cancer screening trial

    Energy Technology Data Exchange (ETDEWEB)

    Heuvelmans, Marjolein A.; Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands); University of Groningen / University Medical Center Groningen, Department of Radiology, Groningen (Netherlands); Oudkerk, Matthijs [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands); Jong, Pim A. de; Mali, Willem P. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Groen, Harry J.M. [University of Groningen, University Medical Center Groningen, Department of Pulmonology, Groningen (Netherlands)

    2014-11-04

    To evaluate the impact of radiological expertise on screen result decisions in a CT lung cancer screening trial. In the NELSON lung cancer screening trial, the baseline CT result was based on the largest lung nodule's volume. The protocol allowed radiologists to manually adjust screen results in cases of high suspicion of benign or malignant nodule nature. Participants whose baseline CT result was based on a solid or part-solid nodule were included in this study. Adjustments by radiologists at baseline were evaluated. Histology was the reference for diagnosis or to confirm benignity and stability on subsequent CT examinations. A total of 3,318 participants (2,796 male, median age 58.0 years) were included. In 195 participants (5.9 %) the initial baseline screen result was adjusted by the radiologist. Adjustment was downwards from positive or indeterminate to negative in two and 119 participants, respectively, and from positive to indeterminate in 65 participants. None of these nodules turned out to be malignant. In 9/195 participants (4.6 %) the screen result was adjusted upwards from negative to indeterminate or indeterminate to positive; two nodules were malignant. In one in 20 cases of baseline lung cancer screening, nodules were reclassified by the radiologist, leading to a reduction of false-positive screen results. (orig.)

  1. Preoperative evaluation of synchronous colorectal cancer using MR colonography

    DEFF Research Database (Denmark)

    Achiam, Michael P; Andersen, Lars Peter Holst; Klein, Mads

    2009-01-01

    it is noninvasive, and most of the colon can be evaluated. Furthermore, it has higher patient acceptance, and no sedation or radiation is used. The purpose of this study was to determine the feasibility of performing MRC preoperatively in an everyday clinical situation in a group of patients who were not offered......RATIONALE AND OBJECTIVES: It is well known that synchronous cancers (incidence, 2%-11%) and polyps (incidence, 12%-58%) occur in patients with colorectal cancer. Magnetic resonance colonography (MRC) seems like the obvious choice as a diagnostic tool in preoperative evaluation, because...

  2. Cost-effectiveness of trauma CT in the trauma room versus the radiology department: the REACT trial

    Energy Technology Data Exchange (ETDEWEB)

    Saltzherr, T.P.; Goslings, J.C. [Academic Medical Center, Trauma Unit Department of Surgery, Amsterdam (Netherlands); Bakker, F.C. [VU University Medical Center, Department of Traumatology, Amsterdam (Netherlands); Beenen, L.F.M. [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Olff, M. [Academic Medical Center, AMC de Meren, Department of Psychiatry, Amsterdam (Netherlands); Meijssen, K. [VU University Medical Center, Economics Department, Amsterdam (Netherlands); Asselman, F.F. [Academic Medical Center, Concern Staff Department, Amsterdam (Netherlands); Reitsma, J.B. [Academic Medical Center, Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam (Netherlands); Dijkgraaf, M.G.W. [Academic Medical Center, Clinical Research Unit, Amsterdam (Netherlands); Collaboration: on behalf of the REACT study group

    2013-01-15

    To determine the cost-effectiveness of trauma room CT compared with CT performed at the radiology department. In this randomised controlled trial, adult patients requiring evaluation in a level 1 trauma centre were included. In the intervention hospital the CT system was located within the trauma room and in the control hospital within the radiology department. Direct and indirect medical costs of the institutionalised stay and diagnostic and therapeutic procedures were calculated. A total of 1,124 patients were randomised with comparable demographic characteristics. Mean number of non-institutionalised days alive was 322.5 in the intervention group (95 % CI 314-331) and 320.7 in the control group (95 % CI 312.1-329.2). Mean costs of diagnostic and therapeutic procedures per hospital inpatient day were EUR554 for the intervention group and EUR468 for the control group. Total mean costs in the intervention group were EUR16,002 (95 % CI 13,075-18,929) and EUR16,635 (95 % CI 13,528-19,743) for the control group (P = 0.77). The present study showed that in trauma patients the setting with a CT system located in the trauma room did not provide any advantages or disadvantages from a health economics perspective over a CT system located in the radiology department. (orig.)

  3. Lung cancer risk prediction to select smokers for screening CT--a model based on the Italian COSMOS trial.

    Science.gov (United States)

    Maisonneuve, Patrick; Bagnardi, Vincenzo; Bellomi, Massimo; Spaggiari, Lorenzo; Pelosi, Giuseppe; Rampinelli, Cristiano; Bertolotti, Raffaella; Rotmensz, Nicole; Field, John K; Decensi, Andrea; Veronesi, Giulia

    2011-11-01

    Screening with low-dose helical computed tomography (CT) has been shown to significantly reduce lung cancer mortality but the optimal target population and time interval to subsequent screening are yet to be defined. We developed two models to stratify individual smokers according to risk of developing lung cancer. We first used the number of lung cancers detected at baseline screening CT in the 5,203 asymptomatic participants of the COSMOS trial to recalibrate the Bach model, which we propose using to select smokers for screening. Next, we incorporated lung nodule characteristics and presence of emphysema identified at baseline CT into the Bach model and proposed the resulting multivariable model to predict lung cancer risk in screened smokers after baseline CT. Age and smoking exposure were the main determinants of lung cancer risk. The recalibrated Bach model accurately predicted lung cancers detected during the first year of screening. Presence of nonsolid nodules (RR = 10.1, 95% CI = 5.57-18.5), nodule size more than 8 mm (RR = 9.89, 95% CI = 5.84-16.8), and emphysema (RR = 2.36, 95% CI = 1.59-3.49) at baseline CT were all significant predictors of subsequent lung cancers. Incorporation of these variables into the Bach model increased the predictive value of the multivariable model (c-index = 0.759, internal validation). The recalibrated Bach model seems suitable for selecting the higher risk population for recruitment for large-scale CT screening. The Bach model incorporating CT findings at baseline screening could help defining the time interval to subsequent screening in individual participants. Further studies are necessary to validate these models.

  4. Effect of CT screening on smoking habits at 1-year follow-up in the Danish Lung Cancer Screening Trial (DLCST)

    DEFF Research Database (Denmark)

    Ashraf, H; Tønnesen, P; Holst Pedersen, J

    2008-01-01

    (DLCST), a 5-year randomised controlled trial comprising 4104 subjects; 2052 subjects received annual low-dose CT scan (CT group) and 2052 received no intervention (control group). Participants were healthy current and former smokers (>4 weeks since smoking cessation) with a tobacco consumption of >20...

  5. Analyzing SNOMED CT and HL7 terminology binding for semantic interoperability on post-genomic clinical trials.

    Science.gov (United States)

    Aso, Santiago; Perez-Rey, David; Alonso-Calvo, Raul; Rico-Diez, Antonio; Bucur, Anca; Claerhout, Brecht; Maojo, Victor

    2013-01-01

    Current post-genomic clinical trials in cancer involve the collaboration of several institutions. Multi-centric retrospective analysis requires advanced methods to ensure semantic interoperability. In this scenario, the objective of the EU funded INTEGRATE project, is to provide an infrastructure to share knowledge and data in post-genomic breast cancer clinical trials. This paper presents the process carried out in this project, to bind domain terminologies in the area, such as SNOMED CT, with the HL7 v3 Reference Information Model (RIM). The proposed terminology binding follow the HL7 recommendations, but should also consider important issues such as overlapping concepts and domain terminology coverage. Although there are limitations due to the large heterogeneity of the data in the area, the proposed process has been successfully applied within the context of the INTEGRATE project. An improvement in semantic interoperability of patient data from modern breast cancer clinical trials, aims to enhance the clinical practice in oncology.

  6. Smoking habits in the randomised Danish Lung Cancer Screening Trial with low-dose CT

    DEFF Research Database (Denmark)

    Ashraf, Haseem; Saghir, Zaigham; Dirksen, Asger

    2014-01-01

    to annual low-dose CT (CT group) and 2052 received no intervention (control group). Participants were current and ex-smokers (≥4 weeks abstinence from smoking) with a tobacco consumption of ≥20 pack years. Smoking habits were determined annually. Missing values for smoking status at the final screening...

  7. Body Size-Specific Organ and Effective Doses of Chest CT Screening Examinations of the National Lung Screening Trial.

    Science.gov (United States)

    Lee, Choonsik; Flynn, Michael J; Judy, Phillip F; Cody, Dianna D; Bolch, Wesley E; Kruger, Randell L

    2017-05-01

    We calculated body size-specific organ and effective doses for 23,734 participants in the National Lung Screening Trial (NLST) using a CT dose calculator. We collected participant-specific technical parameters of 23,734 participants who underwent CT in the clinical trial. For each participant, we calculated two sets of organ doses using two methods. First, we computed body size-specific organ and effective doses using the National Cancer Institute CT (NCICT) dosimetry program, which is based on dose coefficients derived from a library of body size-dependent adult male and female computational phantoms. We then recalculated organ and effective doses using dose coefficients from reference size phantoms for all examinations to investigate potential errors caused by the lack of body size consideration in the dose calculations. The underweight participants (body mass index [BMI; weight in kilograms divided by the square of height in meters] 30) (3.90 mGy). Thyroid doses were approximately 1.3- to 1.6-fold greater than the lung doses (6.3-6.5 mGy). The reference phantom-based dose calculation underestimates the body size-specific lung dose by up to 50% for the underweight participants and overestimates that value by up to 200% for the overweight participants. The median effective dose ranges from 2.01 mSv in obese participants to 2.80 mSv in underweight participants. Body size-specific organ and effective doses were computed for 23,734 NLST participants who underwent low-dose CT screening. The use of reference size phantoms can lead to significant errors in organ dose estimates when body size is not considered in the dose assessment.

  8. CT screening for lung cancer brings forward early disease. The Randomised Danish Lung Cancer Screening Trial (DLCST)

    DEFF Research Database (Denmark)

    Saghir, Zaigham; Dirksen, Asger; Ashraf, Haseem

    2012-01-01

    BackgroundThe effects of low-dose CT screening on disease stage shift, mortality and overdiagnosis are unclear. Lung cancer findings and mortality rates are reported at the end of screening in the Danish Lung Cancer Screening Trial.Methods4104 men and women, healthy heavy smokers/former smokers...... increase and/or volume doubling time15 mm were referred for diagnostic workup. In the control group, lung cancers were diagnosed and treated outside the study by the usual clinical practice.ResultsParticipation rates were high in both groups (screening: 95.5%; control: 93.0%; p...

  9. Common findings and pseudolesions at computed tomography colonography: pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Atzingen, Augusto Castelli von [Clinical Radiology, Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil); Tiferes, Dario Ariel; Matsumoto, Carlos Alberto; Nunes, Thiago Franchi; Maia, Marcos Vinicius Alvim Soares [Abdominal Imaging Section, Department of Imaging Diagnosis - Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil); D' Ippolito, Giuseppe, E-mail: giuseppe_dr@uol.com.br [Department of Imaging Diagnosis, Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil)

    2012-05-15

    Computed tomography colonography is a minimally invasive method for screening for polyps and colorectal cancer, with extremely unusual complications, increasingly used in the clinical practice. In the last decade, developments in bowel preparation, imaging, and in the training of investigators have determined a significant increase in the method sensitivity. Images interpretation is accomplished through a combined analysis of two-dimensional source images and several types of three-dimensional renderings, with sensitivity around 96% in the detection of lesions with dimensions equal or greater than 10 mm in size, when analyzed by experienced radiologists. The present pictorial essay includes examples of diseases and pseudolesions most frequently observed in this type of imaging study. The authors present examples of flat and polypoid lesions, benign and malignant lesions, diverticular disease of the colon, among other conditions, as well as pseudolesions, including those related to inappropriate bowel preparation and misinterpretation. (author)

  10. Iatrogenic Colonic Perforation due to Computed Tomographic Colonography

    Directory of Open Access Journals (Sweden)

    Takashi Kato

    2015-05-01

    Full Text Available Although the complications of computed tomographic colonography (CTC are very rare, CTC is associated with potential risk of colonic perforation. In the present report we describe two cases of colonic perforation secondary to CTC. In the first case with ascending colonic carcinoma, insertion of a rigid double-balloon catheter caused direct rectal wall perforation. In the second case with obstructive colonic carcinoma, pneumoperitoneum developed due to automated carbon dioxide insufflation. Both patients were asymptomatic after examination and recovered without any complications. Based on the findings of the current cases, we recommend that a soft-tip catheter be used for CTC, and suggest that colonic perforation can occur even with automatic insufflation, depending on patient characteristics.

  11. Parallel imaging enhanced MR colonography using a phantom model.

    LENUS (Irish Health Repository)

    Morrin, Martina M

    2008-09-01

    To compare various Array Spatial and Sensitivity Encoding Technique (ASSET)-enhanced T2W SSFSE (single shot fast spin echo) and T1-weighted (T1W) 3D SPGR (spoiled gradient recalled echo) sequences for polyp detection and image quality at MR colonography (MRC) in a phantom model. Limitations of MRC using standard 3D SPGR T1W imaging include the long breath-hold required to cover the entire colon within one acquisition and the relatively low spatial resolution due to the long acquisition time. Parallel imaging using ASSET-enhanced T2W SSFSE and 3D T1W SPGR imaging results in much shorter imaging times, which allows for increased spatial resolution.

  12. Clinical aspects of MR colonography as a diagnostic tool

    DEFF Research Database (Denmark)

    Achiam, Michael

    2010-01-01

    Since first described in 1997, MR colonography (MRC) has since been labelled as a promising new, non-invasive technique for examining the colon. At present time, the examination is ready to be implemented as a supplement to incomplete colonoscopy or preoperative colonic evaluation. Furthermore, MRC...... and that polypectomy might be curative. Colonoscopy remains the gold standard for full colon evaluation. However, the result of our studies can justify clinical use of MRC on selected indications, e.g. in the cases where colonoscopy is incomplete or technically difficult. Since up to 54% of all preoperative colon...... evaluations in patients with colorectal cancer and up to 17-23% of regular colonoscopies are incomplete, the clinical potential of MRC is evident. Furthermore, in our studies we have shown the insufficiency of preoperative colonic evaluation by CC. In addition, considering the invasiveness, the serious...

  13. Randomized controlled trial of relaxation music to reduce heart rate in patients undergoing cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Ming Yen [University of Toronto, Department of Medical Imaging, Toronto General Hospital, Toronto, ON (Canada); The University of Hong Kong, Queen Mary Hospital, Department of Diagnostic Radiology, Hong Kong (China); Karimzad, Yasser; Menezes, Ravi J.; Wintersperger, Bernd J.; Li, Qin; Forero, Julian; Paul, Narinder S.; Nguyen, Elsie T. [University of Toronto, Department of Medical Imaging, Toronto General Hospital, Toronto, ON (Canada)

    2016-10-15

    To evaluate the heart rate lowering effect of relaxation music in patients undergoing coronary CT angiography (CCTA), pulmonary vein CT (PVCT) and coronary calcium score CT (CCS). Patients were randomised to a control group (i.e. standard of care protocol) or to a relaxation music group (ie. standard of care protocol with music). The groups were compared for heart rate, radiation dose, image quality and dose of IV metoprolol. Both groups completed State-Trait Anxiety Inventory anxiety questionnaires to assess patient experience. One hundred and ninety-seven patients were recruited (61.9 % males); mean age 56y (19-86 y); 127 CCTA, 17 PVCT, 53 CCS. No significant difference in heart rate, radiation dose, image quality, metoprolol dose and anxiety scores. 86 % of patients enjoyed the music. 90 % of patients in the music group expressed a strong preference to have music for future examinations. The patient cohort demonstrated low anxiety levels prior to CT. Relaxation music in CCTA, PVCT and CCS does not reduce heart rate or IV metoprolol use. Patients showed low levels of anxiety indicating that anxiolytics may not have a significant role in lowering heart rate. Music can be used in cardiac CT to improve patient experience. (orig.)

  14. Lung cancer probability in patients with CT-detected pulmonary nodules: a prespecified analysis of data from the NELSON trial of low-dose CT screening.

    Science.gov (United States)

    Horeweg, Nanda; van Rosmalen, Joost; Heuvelmans, Marjolein A; van der Aalst, Carlijn M; Vliegenthart, Rozemarijn; Scholten, Ernst Th; ten Haaf, Kevin; Nackaerts, Kristiaan; Lammers, Jan-Willem J; Weenink, Carla; Groen, Harry J; van Ooijen, Peter; de Jong, Pim A; de Bock, Geertruida H; Mali, Willem; de Koning, Harry J; Oudkerk, Matthijs

    2014-11-01

    The main challenge in CT screening for lung cancer is the high prevalence of pulmonary nodules and the relatively low incidence of lung cancer. Management protocols use thresholds for nodule size and growth rate to determine which nodules require additional diagnostic procedures, but these should be based on individuals' probabilities of developing lung cancer. In this prespecified analysis, using data from the NELSON CT screening trial, we aimed to quantify how nodule diameter, volume, and volume doubling time affect the probability of developing lung cancer within 2 years of a CT scan, and to propose and evaluate thresholds for management protocols. Eligible participants in the NELSON trial were those aged 50-75 years, who have smoked 15 cigarettes or more per day for more than 25 years, or ten cigarettes or more for more than 30 years and were still smoking, or had stopped smoking less than 10 years ago. Participants were randomly assigned to low-dose CT screening at increasing intervals, or no screening. We included all participants assigned to the screening group who had attended at least one round of screening, and whose results were available from the national cancer registry database. We calculated lung cancer probabilities, stratified by nodule diameter, volume, and volume doubling time and did logistic regression analysis using diameter, volume, volume doubling time, and multinodularity as potential predictor variables. We assessed management strategies based on nodule threshold characteristics for specificity and sensitivity, and compared them to the American College of Chest Physicians (ACCP) guidelines. The NELSON trial is registered at www.trialregister.nl, number ISRCTN63545820. Volume, volume doubling time, and volumetry-based diameter of 9681 non-calcified nodules detected by CT screening in 7155 participants in the screening group of NELSON were used to quantify lung cancer probability. Lung cancer probability was low in participants with a nodule

  15. Evaluation of contrast-enhanced computed tomographic colonography in detection of local recurrent colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Yau-Tong You; Chung-Rong Chang Chien; Jeng-Yi Wang; Koon-Kwan Ng; Jinn-Shiun Chen; Reiping Tang; Jy-Ming Chiang; Chien-Yuh Yeh; Pao-Shiu Hsieh

    2006-01-01

    AIM: To evaluate the diagnostic accuracy, sensitivity,specificity of contrast-enhanced computed tomographic colonography in detecting local recurrence of colorectal cancer.METHODS: From January 2000 to December 2004,434 patients after potentially curative resection for invasive colorectal cancer were followed up for a period ranging from 20 to 55 mo. Eighty of the four hundred and thirty-four patients showing strong clinical evidence for recurring colorectal cancer during the last followup were enrolled in this study. Each patient underwent contrast-enhanced computed tomographic colonography and colonoscopy on the same day. Any lesions, biopsies,identified during the colonoscopic examination, immediate complications and the duration of the procedure were recorded. The results of contrast-enhanced computed tomographic colonography were evaluated by comparing to those of colonoscopy, surgical finding, and clinical follow-up.RESULTS: Contrast-enhanced computed tomographic colonography had a sensitivity of 100%, a specificity of 83% and an overall accuracy of 94% in detecting local recurrent colorectal cancer.CONCLUSION: Conventional colonoscopy and contrastenhanced tomographic colonography can complement each other in detecting local recurrence of colorectal cancer.

  16. A virtual clinical trial using projection-based nodule insertion to determine radiologist reader performance in lung cancer screening CT

    Science.gov (United States)

    Yu, Lifeng; Hu, Qiyuan; Koo, Chi Wan; Takahashi, Edwin A.; Levin, David L.; Johnson, Tucker F.; Hora, Megan J.; Dirks, Shane; Chen, Baiyu; McMillan, Kyle; Leng, Shuai; Fletcher, J. G.; McCollough, Cynthia H.

    2017-03-01

    Task-based image quality assessment using model observers is promising to provide an efficient, quantitative, and objective approach to CT dose optimization. Before this approach can be reliably used in practice, its correlation with radiologist performance for the same clinical task needs to be established. Determining human observer performance for a well-defined clinical task, however, has always been a challenge due to the tremendous amount of efforts needed to collect a large number of positive cases. To overcome this challenge, we developed an accurate projection-based insertion technique. In this study, we present a virtual clinical trial using this tool and a low-dose simulation tool to determine radiologist performance on lung-nodule detection as a function of radiation dose, nodule type, nodule size, and reconstruction methods. The lesion insertion and low-dose simulation tools together were demonstrated to provide flexibility to generate realistically-appearing clinical cases under well-defined conditions. The reader performance data obtained in this virtual clinical trial can be used as the basis to develop model observers for lung nodule detection, as well as for dose and protocol optimization in lung cancer screening CT.

  17. Patient acceptance of MR colonography with improved fecal tagging versus conventional colonoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Achiam, M.P. [Department of Diagnostic Radiology and Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark)], E-mail: achiam1@dadlnet.dk; Logager, V.; Chabanova, E.; Thomsen, H.S.; Rosenberg, J. [Department of Diagnostic Radiology and Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark)

    2010-01-15

    Objective: Conventional colonoscopy (CC) is the gold standard for colonic examinations. However, patient acceptance is not high. Patient acceptance is influenced by several factors, notably anticipation and experience. This has led to the assumption that patient acceptance would be higher in non-invasive examinations such as MR/CT colonography (MRC/CTC) and perhaps even higher without bowel preparation. The purpose of this study was to evaluate patient acceptance of MRC with fecal tagging versus CC. Materials and methods: In a 14-month period, all patients first-time referred to our department for CC were asked to participate in the study. Two days prior to MRC, patients ingested an oral contrast mixture (barium/ferumoxsil) together with four meals each day. Standard bowel purgation was performed before CC. Before and after MRC and CC a number of questions were addressed. Results: Sixty-four (34 men, 30 women) patients referred for CC participated in the study. 27% had some discomfort ingesting the contrast mixture, and 49% had some discomfort with the bowel purgation. As a future colonic examination preference, 71% preferred MRC, 13% preferred CC and 15% had no preference. If MRC was to be performed with bowel purgation, 75% would prefer MRC, 12% would prefer CC and 12% had no preference. Conclusion: This study shows that there is a potential gain in patient acceptance by using MRC for colonic examination, since MRC is considered less painful and less unpleasant than CC. In addition, the results indicate that patients in this study prefer fecal tagging instead of bowel purgation.

  18. Prediction of outcome in patients with suspected acute ischaemic stroke with CT perfusion and CT angiography: the Dutch acute stroke trial (DUST) study protocol

    NARCIS (Netherlands)

    Seeters, T. van; Biessels, G.J.; Schaaf, I.C. van der; Dankbaar, J.W.; Horsch, A.D.; Luitse, M.J.; Niesten, J.M.; Mali, W.P.Th.; Kappelle, L.J.; Graaf, Y. van der; Velthuis, B.K.; Dijk, E.J. van

    2014-01-01

    BACKGROUND: Prediction of clinical outcome in the acute stage of ischaemic stroke can be difficult when based on patient characteristics, clinical findings and on non-contrast CT. CT perfusion and CT angiography may provide additional prognostic information and guide treatment in the early stage. We

  19. Colovesical fistula causing an uncommon reason for failure of computed tomography colonography: a case report

    Directory of Open Access Journals (Sweden)

    Neroladaki Angeliki

    2012-07-01

    Full Text Available Abstract Introduction Computed tomography colonography, or virtual colonoscopy, is a good alternative to optical colonoscopy. However, suboptimal patient preparation or colon distension may reduce the diagnostic accuracy of this imaging technique. Case presentation We report the case of an 83-year-old Caucasian woman who presented with a five-month history of pneumaturia and fecaluria and an acute episode of macrohematuria, leading to a high clinical suspicion of a colovesical fistula. The fistula was confirmed by standard contrast-enhanced computed tomography. Optical colonoscopy was performed to exclude the presence of an underlying colonic neoplasm. Since optical colonoscopy was incomplete, computed tomography colonography was performed, but also failed due to inadequate colon distension. The insufflated air directly accumulated within the bladder via the large fistula. Conclusions Clinicians should consider colovesical fistula as a potential reason for computed tomography colonography failure.

  20. Colorectal neoplasm: Magnetic resonance colonography with fat enema-initial clinical experience

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To assess Magnetic resonance colonography with fat enema as a method for detection of colorectal neoplasm. METHODS: Consecutive twenty-two patients underwent MR colonography with fat enema before colonoscopy. T1-weighted three-dimensional fast spoiled gradientecho with inversion recovery sequence was acquired with the patient in the supine position before and 75 s after Gadopentetate Dimelumine administration. Where by, pre and post MR coronal images were obtained with a single breath hold for about 20 s to cover the entire colon. The quality of MR colonographs and patients' tolerance to fat contrast medium was investigated. Colorectal neoplasms identified by MR colonography were compared with those identified on colonoscopy and sensitivity of detecting the lesions was calculated accordingly. RESULTS: MR colonography with fat enema was well tolerated without sedation and analgesia. 120 out of 132 (90.9%) colonic segments were well distended and only 1 (0.8%) colonic segment was poor distension. After contrast enhancement scan, mean contrast-to-noise ratio (CNR) value between the normal colonic wall and lumen was 18.5 ± 2.9 while mean CNR value between colorectal neoplasm and lumen was 20.2 ± 3.1. By Magnetic resonance colonography, 26 of 35 neoplasms (sensitivity 74.3%) were detected. However, sensitivity of MRC was 95.5% (21 of 22) for neoplasm larger than 10 mm and 55.6% (5 of 9) for 5-10 mm neoplasm. CONCLUSION: MR colonography with fat enema and T1-weighted three-dimensional fast spoiled gradientecho with inversion recovery sequence is feasible in detecting colorectal neoplasm larger than 10 mm.

  1. Preliminary study on MR colonography with air enema in detection of colorectal neoplasms

    Institute of Scientific and Technical Information of China (English)

    LUO Ming-yue; LIU Li; YAN Fu-hua; SHEN Ji-zhang; YAO Li-qing; ZHOU Kang-rong

    2010-01-01

    Background The few studies on MR colonography with air enema involved feasibility of bowel distention and imaging quality and lacked detection sensitivity of colorectal neoplasms. The purpose of this prospective study was to assess the detection sensitivity of colorectal neoplasms with the three-dimensional Fourier transform fast spoiled gradient-recalled MR colonography with air enema.Methods A total of 30 patients scheduled for optical colonoscopy due to rectal bleeding, positive fecal occult blood test results or altered bowel habits were recruited and successfully underwent entire colorectal examinations with three-dimensional Fourier transform fast spoiled gradient-recalled MR colonography and subsequent optical colonoscopy on the same day. Detection sensitivity of colorectal neoplasms with MR colonography was statistically analyzed on a per-neoplasm size basis by using findings from optical colonoscopy and histopathological examinations as the reference standards.Results Seventy-six neoplasms were detected with optical colonoscopy, consisting of 1 mm-5 mm (n=11), 6 mm-9 mm (n=29) and >10 mm (n=36) in diameter. Detection sensitivities of 1 mm-5 mm, 6 mm-9 mm, ≥10 mm and >6 mm colorectal neoplasms with MR colonography were 9.1%, 75.9%, 100% and 89.2%, respectively; overall detection sensitivity for all sizes colorectal neoplasms was 77.6%.Conclusions Detection sensitivity of three-dimensional Fourier transform fast spoiled gradient-recalled MR colonography with air enema is low for 1 mm-5 mm colorectal neoplasms, but the detection sensitivity is 89.2% for ≥6 mm neoplasms, and all ≥10 mm neoplasms could be detected.

  2. Renal Sympathetic Denervation by CT-Guided Ethanol Injection: A Phase II Pilot Trial of a Novel Technique

    Energy Technology Data Exchange (ETDEWEB)

    Ricke, J., E-mail: jens.ricke@med.ovgu.de; Seidensticker, M.; Becker, S. [Otto-von-Guericke University Magdeburg, Department of Radiology and Nuclear Medicine, Universitätsklinikum Magdeburg AöR (Germany); Schiefer, J. [Universitätsklinikum Magdeburg AöR, Department of Nephrology and Hypertension, Diabetes and Endocrinology (Germany); Adamchic, I.; Lohfink, K. [Otto-von-Guericke University Magdeburg, Department of Radiology and Nuclear Medicine, Universitätsklinikum Magdeburg AöR (Germany); Kandulski, M.; Heller, A.; Mertens, P. R. [Universitätsklinikum Magdeburg AöR, Department of Nephrology and Hypertension, Diabetes and Endocrinology (Germany)

    2016-02-15

    ObjectivesCT-guided ethanol-mediated renal sympathetic denervation in treatment of therapy-resistant hypertension was performed to assess patient safety and collect preliminary data on treatment efficacy.Materials and MethodsEleven patients with therapy-resistant hypertension (blood pressure of >160 mmHg despite three different antihypertensive drugs including a diuretic) and following screening for secondary causes were enrolled in a phase II single arm open label pilot trial of CT-guided neurolysis of sympathetic renal innervation. Primary endpoint was safety, and secondary endpoint was a decrease of the mean office as well as 24-h systolic blood pressure in follow-up. Follow-up visits at 4 weeks, 3, and 6 months included 24-h blood pressure assessments, office blood pressure, laboratory values, as well as full clinical and quality of life assessments.ResultsNo toxicities ≥3° occurred. Three patients exhibited worsened kidney function in follow-up analyses. When accounting all patients, office systolic blood pressure decreased significantly at all follow-up visits (maximal mean decrease −41.2 mmHg at 3 months). The mean 24-h systolic blood pressure values decreased significantly at 3 months, but not at 6 months (mean: −9.7 and −6.3 mmHg, respectively). Exclusion of five patients who had failed catheter-based endovascular denervation and/or were incompliant for antihypertensive drug intake revealed a more pronounced decrease of 24-h systolic blood pressure (mean: −18.3 and −15.2 mmHg at 3 and 6 months, p = 0.03 and 0.06).ConclusionCT-guided sympathetic denervation proved to be safe and applicable under various anatomical conditions with more renal arteries and such of small diameter.

  3. Survey update on implementation, indications, and technical performance of computed tomography colonography in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Fisichella, Valeria A.; Hellstroem, Mikael (Dept. of Radiology, Sahlgrenska Univ. Hospital and Sahlgrenska Academy at Univ. of Goeteborg, Goeteborg (Sweden)), e-mail: valeria.fisichella@vgregion.se

    2010-01-15

    Background: Computed tomographic colonography (CTC) has gained increased acceptance in the last few years as a valid substitute for double-contrast barium enema (DCBE). However, implementation of new technologies is complex, since several factors may influence the process. Purpose: To evaluate the current situation in Sweden concerning implementation of CTC, as compared to a previous national survey in 2005. Material and Methods: In December 2008, a structured, self-assessed questionnaire regarding implementation and technical performance of CTC was mailed to all radiology departments in Sweden. In March 2009, departments who had not replied were contacted by e-mail or by telephone. All (100%, 119/119) departments answered the questionnaire. Results: CTC is currently performed in 50/119 (42%) departments, i.e., 18 additional departments compared to 2005. Twenty-three out of 60 (38%) responding departments stated that they intend to start to perform CTC in the near future. DCBE is currently performed in 77/119 (65%) departments, 12 departments less compared to 2005. The most common reasons for non-implementation of CTC are non-availability of spiral CT scanner (41%, 26/64) and/or multidetector-row CT scanner (39%, 25/64), and lack of doctors' time (34%, 22/64). Only 3% (2/64) of departments are 'awaiting further scientific documentation' on CTC, a significant reduction compared to 2005 (P=0.002). Until 2009, 59% (29/49) of CTC centers had performed more than 200 CTCs compared to 13% (4/32) of CTC centers in 2005. Intravenous contrast material is routinely administered in 86% (42/49), and carbon dioxide is used to distend the colon in 90% (44/49). Almost all radiology departments (93%, 93/100) currently believe that CTC will 'absolutely' or 'probably' replace barium enema in the future, while in 2005 only 56% (55/99) gave similar answers. Conclusion: The survey reflects a further transition process from DCBE to CTC, with attitudes

  4. An evaluation of a Shockroom located CT scanner: a randomized study of early assessment by CT scanning in trauma patients in the bi-located trauma center North-West Netherlands (REACT trial)

    Science.gov (United States)

    Saltzherr, Teun P; Jin, PH Ping Fung Kon; Bakker, Fred C; Ponsen, Kees J; Luitse, Jan SK; Scholing, Mark; Giannakopoulos, Georgios F; Beenen, Ludo FM; Henny, C Pieter; Koole, Ger M; Reitsma, Hans B; Dijkgraaf, Marcel GW; Bossuyt, Patrick MM; Goslings, J Carel

    2008-01-01

    Background Trauma is a major source of morbidity and mortality, especially in people below the age of 50 years. For the evaluation of trauma patients CT scanning has gained wide acceptance in and provides detailed information on location and severity of injuries. However, CT scanning is frequently time consuming due to logistical (location of CT scanner elsewhere in the hospital) and technical issues. An innovative and unique infrastructural change has been made in the AMC in which the CT scanner is transported to the patient instead of the patient to the CT scanner. As a consequence, early shockroom CT scanning provides an all-inclusive multifocal diagnostic modality that can detect (potentially life-threatening) injuries in an earlier stage, so that therapy can be directed based on these findings. Methods/design The REACT-trial is a prospective, randomized trial, comparing two Dutch level-1 trauma centers, respectively the VUmc and AMC, with the only difference being the location of the CT scanner (respectively in the Radiology Department and in the shockroom). All trauma patients that are transported to the AMC or VUmc shockroom according to the current prehospital triage system are included. Patients younger than 16 years of age and patients who die during transport are excluded. Randomization will be performed prehospitally. Study parameters are the number of days outside the hospital during the first year following the trauma (primary outcome), general health at 6 and 12 months post trauma, mortality and morbidity, and various time intervals during initial evaluation. In addition a cost-effectiveness analysis of this shockroom concept will be performed. Regarding primary outcome it is estimated that the common standard deviation of days spent outside of the hospital during the first year following trauma is a total of 12 days. To detect an overall difference of 2 days within the first year between the two strategies, 562 patients per group are needed. (alpha

  5. An evaluation of a Shockroom located CT scanner: a randomized study of early assessment by CT scanning in trauma patients in the bi-located trauma center North-West Netherlands (REACT trial

    Directory of Open Access Journals (Sweden)

    Reitsma Hans B

    2008-08-01

    Full Text Available Abstract Background Trauma is a major source of morbidity and mortality, especially in people below the age of 50 years. For the evaluation of trauma patients CT scanning has gained wide acceptance in and provides detailed information on location and severity of injuries. However, CT scanning is frequently time consuming due to logistical (location of CT scanner elsewhere in the hospital and technical issues. An innovative and unique infrastructural change has been made in the AMC in which the CT scanner is transported to the patient instead of the patient to the CT scanner. As a consequence, early shockroom CT scanning provides an all-inclusive multifocal diagnostic modality that can detect (potentially life-threatening injuries in an earlier stage, so that therapy can be directed based on these findings. Methods/design The REACT-trial is a prospective, randomized trial, comparing two Dutch level-1 trauma centers, respectively the VUmc and AMC, with the only difference being the location of the CT scanner (respectively in the Radiology Department and in the shockroom. All trauma patients that are transported to the AMC or VUmc shockroom according to the current prehospital triage system are included. Patients younger than 16 years of age and patients who die during transport are excluded. Randomization will be performed prehospitally. Study parameters are the number of days outside the hospital during the first year following the trauma (primary outcome, general health at 6 and 12 months post trauma, mortality and morbidity, and various time intervals during initial evaluation. In addition a cost-effectiveness analysis of this shockroom concept will be performed. Regarding primary outcome it is estimated that the common standard deviation of days spent outside of the hospital during the first year following trauma is a total of 12 days. To detect an overall difference of 2 days within the first year between the two strategies, 562 patients per

  6. A multicentre randomised controlled trial to compare the pharmacokinetics, efficacy and safety of CT-P10 and innovator rituximab in patients with rheumatoid arthritis

    Science.gov (United States)

    Yoo, Dae Hyun; Suh, Chang-Hee; Shim, Seung Cheol; Jeka, Slawomir; Cons-Molina, Francisco Fidencio; Hrycaj, Pawel; Wiland, Piotr; Lee, Eun Young; Medina-Rodriguez, Francisco G; Shesternya, Pavel; Radominski, Sebastiao; Stanislav, Marina; Kovalenko, Volodymyr; Sheen, Dong Hyuk; Myasoutova, Leysan; Lim, Mie Jin; Choe, Jung-Yoon; Lee, Sang Joon; Lee, Sung Young; Kwon, Taek Sang; Park, Won

    2017-01-01

    Objective To demonstrate pharmacokinetic equivalence of CT-P10 and innovator rituximab (RTX) in patients with rheumatoid arthritis (RA) with inadequate responses or intolerances to antitumour necrosis factor agents. Methods In this randomised phase I trial, patients with active RA were randomly assigned (2:1) to receive 1000 mg CT-P10 or RTX at weeks 0 and 2 (alongside continued methotrexate therapy). Primary endpoints were area under the serum concentration–time curve from time zero to last quantifiable concentration (AUC0–last) and maximum serum concentration after second infusion (Cmax). Additional pharmacokinetic parameters, efficacy, pharmacodynamics, immunogenicity and safety were also assessed. Data are reported up to week 24. Results 103 patients were assigned to CT-P10 and 51 to RTX. The 90% CIs for the ratio of geometric means (CT-P10/RTX) for both primary endpoints were within the bioequivalence range of 80%–125% (AUC0–last: 97.7% (90% CI 89.2% to 107.0%); Cmax: 97.6% (90% CI 92.0% to 103.5%)). Pharmacodynamics and efficacy were comparable between groups. Antidrug antibodies were detected in 17.6% of patients in each group at week 24. CT-P10 and RTX displayed similar safety profiles. Conclusions CT-P10 and RTX demonstrated equivalent pharmacokinetics and comparable efficacy, pharmacodynamics, immunogenicity and safety. Trial registration number NCT01534884. PMID:27624791

  7. WE-B-207-01: CT Lung Cancer Screening and the Medical Physicist: Background, Findings and Participant Dosimetry Summary of the National Lung Screening Trial (NLST)

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, R. [Marshfield Clinic, Marshfield, WI (United States)

    2015-06-15

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  8. Biosurveillance evaluation of SNOMED CT's terminology (BEST Trial): coverage of chief complaints.

    Science.gov (United States)

    Elkin, Peter L; Brown, Steven H; Balas, Andrew; Temesgen, Zelalem; Wahner-Roedler, Dietlind; Froehling, David; Liebow, Mark; Trusko, Brett; Rosenbloom, S Trent; Poland, Greg

    2008-01-01

    The current United States Health Information Technology Standards Panel's interoperability specification for biosurveillance relies heavily on chief complaint data for tracking rates of cases compatible with a case definition for diseases of interest (e.g. Avian Flu). We looked at SNOMED CT to determine how well this large general medical ontology could represent data held in chief complaints. In this experiment we took 50,000 records (Comprehensive Examinations or Limited Examinations from primary care areas at the Mayo Clinic) from December 2003 through February 2005 (Influenza Season). Of these records, 36,097 had non-null Chief Complaints. We randomly selected 1,035 non-null Chief Complaints and two Board-certified internists (one Infectious Diseases specialist and one general internist) reviewed the mappings of the 1,035 chief complaints. Where the reviewers disagreed, a third internist adjudicated. SNOMED CT had a sensitivity of 98.7% for matching clinical terms found in the chief complaint section of the clinical record. The positive predictive value was 97.4%, the negative predictive value was 89.5%, the specificity was 81.0%, the positive likelihood ratio was 5.181 and the negative likelihood ratio was 0.016. We conclude that SNOMED CT and natural language parsing engines can well represent the clinical content of chief complaint fields. Future research should focus on how well the information contained in the chief complaints can be relied upon to provide the basis of a national strategy for biosurveillance. The authors recommend that efforts be made to examine the entire clinical record to determine the level of improvement in the accuracy of biosurveillance that can be achieved if we were to incorporate the entire clinical record into our biosurveillance strategy.

  9. Magnetic resonance colonography in severe attacks of ulcerative colitis

    Energy Technology Data Exchange (ETDEWEB)

    Savoye-Collet, C.; Roset, J.B.; Koning, E.; Dacher, J.N. [Rouen University Hospital Charles Nicolle, Radiology Department - QUANTIF - LITIS EA 4108, Rouen (France); Charpentier, C.; Hommel, S.; Lerebours, E.; Savoye, G. [Rouen University Hospital Charles Nicolle, Gastroenterology Department - ADEN U 1073, Rouen (France)

    2012-09-15

    To evaluate the ability of MR colonography (MRC) to detect lesions in severe attacks of ulcerative colitis (UC) and to assess its concordance with rectosigmoidoscopy. Eighteen patients underwent MRC and rectosigmoidoscopy. MRC consisted of a water-filled colonic procedure followed by T1/T2w images. Image quality was recorded. Inflammatory lesions and the existence of signs of severity were analysed. We calculated MR accuracy in the diagnosis of inflammatory lesions, as well as per segment and per patient concordance depending on the presence or absence of severe lesions. The MR image quality of the 108 segments was satisfactory. Endoscopy was used to study 36 segments (rectum and sigmoid). MRC had a positive predictive value of 100% and a sensitivity of 64% in the diagnosis of inflammatory lesions. Concordance for the diagnosis of severe lesions was excellent for the rectum (k = 0.85) and good for the sigmoid (k = 0.64). MRC diagnosed signs of severity in all patients affected at endoscopy. MRC also disclosed signs of severity located higher in the colon in four patients with nonsevere lesions at rectosigmoidoscopy. MRC can accurately diagnose inflammatory lesions in severe attacks of UC and significantly correlates with rectosigmoidoscopy in the diagnosis of severe lesions. (orig.)

  10. Adoption of Computed Tomographic Colonography by U.S. Hospitals

    Science.gov (United States)

    McHugh, Megan; Osei-Anto, Awo; Klabunde, Carrie N.; Galen, Barbara A.

    2010-01-01

    Purpose Computed tomographic colonography (CTC) is a new non-invasivetechnology proposed as an option for colorectal cancer screening. The purpose of this study was to identify the percent of U.S. hospitals that offered CTC between 2005 and 2008 and factors that motivated or impeded adoption. Methods We analyzed data on the provision of colorectal cancer screening services by non-federal, general hospitals using the 2005 – 2008 American Hospital Association Annual Surveys. Additionally, in 2009, we conducted exploratory interviews with representatives from radiology departments at nine hospitals – six that provided CTC and three that did not. Results In 2008, 17% of hospitals offered CTC, up from 13% in 2005. Sixty-nine percent of hospitals that offered CTC in 2008 also offered optical colonoscopy services. Factors motivating adoption of CTC included a desire to provide an alternative screening option for frail, elderly patients and patients with a failed optical colonoscopy; long waits for optical colonoscopy; and promising evidence on CTC published in peer-reviewed literature. Lack of reimbursement was a commonly-cited barrier. Conclusion Growth of CTC services at U.S. hospitals occurred even in the absence of Medicare coverage or agreement among national guideline-setting organizations regarding CTC’s use in screening. Almost one-third of hospitals that offer CTC do not offer optical colonoscopy, and may not be prepared to provide adequate follow-up for patients with failed CTCs. PMID:21371666

  11. Qualification of National Cancer Institute-Designated Cancer Centers for Quantitative PET/CT Imaging in Clinical Trials.

    Science.gov (United States)

    Scheuermann, Joshua S; Reddin, Janet S; Opanowski, Adam; Kinahan, Paul E; Siegel, Barry A; Shankar, Lalitha K; Karp, Joel S

    2017-07-01

    The National Cancer Institute developed the Centers for Quantitative Imaging Excellence (CQIE) initiative in 2010 to prequalify imaging facilities at all of the National Cancer Institute-designated comprehensive and clinical cancer centers for oncology trials using advanced imaging techniques, including PET. Here we review the CQIE PET/CT scanner qualification process and results in detail. Methods: Over a period of approximately 5 y, sites were requested to submit a variety of phantoms, including uniform and American College of Radiology-approved phantoms, PET/CT images, and examples of clinical images. Submissions were divided into 3 distinct time periods: initial submission (T0) and 2 requalification submissions (T1 and T2). Images were analyzed using standardized procedures, and scanners received a pass or fail designation. Sites had the opportunity to submit new data for scanners that failed. Quantitative results were compared across scanners within a given time period and across time periods for a given scanner. Results: Data from 65 unique PET/CT scanners across 56 sites were submitted for CQIE T0 qualification; 64 scanners passed the qualification. Data from 44 (68%) of those 65 scanners were submitted for T2. From T0 to T2, the percentage of scanners passing the CQIE qualification on the first attempt rose from 38% for T1 to 67% for T2. The most common reasons for failure were SUV outside specifications, incomplete submission, and uniformity issues. Uniform phantom and American College of Radiology-approved phantom results between scanner manufacturers were similar. Conclusion: The results of the CQIE process showed that periodic requalification may decrease the frequency of deficient data submissions. The CQIE project also highlighted the concern within imaging facilities about the burden of maintaining different qualifications and accreditations. Finally, for quantitative imaging-based trials, further evaluation of the relationships between the level of

  12. Blinded and uniform cause of death verification in a lung cancer CT screening trial

    NARCIS (Netherlands)

    Horeweg, N.; van Klaveren, R. J.; Groen, H. J. M.; Lammers, J. -W. J.; Weenink, C.; Nackaerts, K.; Mali, W.; Oudkerk, M.; de Koning, H. J.

    2012-01-01

    Disease-specific mortality is the final outcome of a lung cancer screening trial, therefore cause of death verification is crucial. The use of death certificates for this purpose is debated because of bias, inaccurate completion and incorrect ante mortem diagnoses. A cause of death evaluation proces

  13. Coronary CT Angiography as a Diagnostic and Prognostic Tool: Perspectives from the SCOT-HEART Trial.

    Science.gov (United States)

    Doris, Mhairi; Newby, David E

    2016-02-01

    Coronary artery disease is the leading cause of death worldwide. Many trials to date have investigated the diagnostic accuracy of coronary computed tomography angiography (CCTA) when compared to the gold standard diagnostic test, invasive coronary angiography. However, whether the use of a non-invasive anatomical test, such as CCTA, can translate into improved patient risk stratification, management and outcome has yet to be established. The Scottish COmputed Tomography of the HEART (SCOT-HEART) trial sought to address these questions and determined whether CCTA, when used in addition to standard care, could aid the diagnosis, further investigation and treatment of patients referred to the cardiology clinic with suspected angina due to coronary heart disease. In this trial, CCTA clarified the diagnosis of angina due to coronary heart disease in a quarter of patients and this led to major alterations in treatment and management that appeared to reduce the risk of subsequent coronary heart disease death or non-fatal myocardial infarction. The SCOT-Heart trial has established that CCTA is a valuable diagnostic test in patients with suspected angina pectoris due to coronary heart disease and leads to greater clarity, more focused appropriate treatments and better coronary heart disease outcomes.

  14. Symptoms and quality of life in patients with suspected angina undergoing CT coronary angiography: a randomised controlled trial

    Science.gov (United States)

    Hunter, Amanda; Shah, Anoop; Assi, Valentina; Lewis, Stephanie; Mangion, Kenneth; Berry, Colin; Boon, Nicholas A; Clark, Elizabeth; Flather, Marcus; Forbes, John; McLean, Scott; Roditi, Giles; van Beek, Edwin JR; Timmis, Adam D; Newby, David E

    2017-01-01

    Background In patients with suspected angina pectoris, CT coronary angiography (CTCA) clarifies the diagnosis, directs appropriate investigations and therapies, and reduces clinical events. The effect on patient symptoms is currently unknown. Methods In a prospective open-label parallel group multicentre randomised controlled trial, 4146 patients with suspected angina due to coronary heart disease were randomised 1:1 to receive standard care or standard care plus CTCA. Symptoms and quality of life were assessed over 6 months using the Seattle Angina Questionnaire and Short Form 12. Results Baseline scores indicated mild physical limitation (74±0.4), moderate angina stability (44±0.4), modest angina frequency (68±0.4), excellent treatment satisfaction (92±0.2) and moderate impairment of quality of life (55±0.3). Compared with standard care alone, CTCA was associated with less marked improvements in physical limitation (difference −1.74 (95% CIs, −3.34 to −0.14), p=0.0329), angina frequency (difference −1.55 (−2.85 to −0.25), p=0.0198) and quality of life (difference −3.48 (−4.95 to −2.01), pcoronary arteries or who had their preventative therapy discontinued, and least in those with moderate non-obstructive disease or had a new prescription of preventative therapy (pcoronary artery disease. Trial registration number: NCT01149590. PMID:28246175

  15. Perioperative Colonic Evaluation in Patients with Rectal Cancer; MR Colonography Versus Standard Care

    DEFF Research Database (Denmark)

    Achiam, Michael Patrick; Løgager, Vibeke; Lund Rasmussen, Vera;

    2015-01-01

    was to prospectively evaluate the completion rate of preoperative colonic evaluation and the quality of perioperative colonic evaluation using magnetic resonance colonography (MRC) in patients with rectal cancer. MATERIALS AND METHODS: Patients diagnosed with rectal cancer were randomized to either group A: standard...... is a valuable tool and is recommended as part of the standard preoperative evaluation for patients with rectal cancer....

  16. MR colonography without colonic cleansing: a new strategy to improve patient acceptance.

    Science.gov (United States)

    Lauenstein, T; Holtmann, G; Schoenfelder, D; Bosk, S; Ruehm, S G; Debatin, J F

    2001-10-01

    MR colonography permits accurate detection of colonic polyps larger than 8 mm. Patient acceptance remains limited because of the need for bowel cleansing. The aim of this study was to develop and assess a strategy obviating colonic cleansing by performing MR colonography in conjunction with fecal tagging based on the oral administration of barium. Six healthy volunteers and six patients with suspected colorectal tumors, undergoing conventional colonoscopy within 1 week of MR imaging, were included in this study. For fecal tagging, 200 mL of a barium-containing contrast agent was ingested with each of four principal meals preceding the examination. For MR colonography, the colon was filled with a barium and water mixture while gadobenate dimeglumine (0.2 mmol/kg) was injected IV. The combination of fecal tagging and colonic filling with barium resulted in a homogeneously low signal throughout the colonic lumen in all 12 subjects. IV injection of gadolinium caused avid enhancement of the colonic wall. Similarly, lesions arising from the colonic wall enhanced avidly. In the six evaluated patients, MR colonography correctly identified two colonic carcinomas in two patients and one polyp in each of another two patients. Fecal tagging obviates bowel cleansing and should, therefore, enhance patient acceptance for MR colonoscopy. Barium used as the tagging agent is promising because it is inexpensive, commercially available, and characterized by an excellent safety profile.

  17. Diagnostic performance of radiographers as compared to radiologists in magnetic resonance colonography

    Energy Technology Data Exchange (ETDEWEB)

    Zijta, F.M., E-mail: f.m.zijta@amc.uva.n [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Department of Radiology, Onze Lieve Vrouwe Gasthuis, Amsterdam (Netherlands); Florie, J., E-mail: j.florie@amc.uva.n [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Jensch, S., E-mail: s.jensch@amc.uva.n [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Department of Radiology, Onze Lieve Vrouwe Gasthuis, Amsterdam (Netherlands); Bipat, S., E-mail: s.bipat@amc.uva.n [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Nievelstein, R.A.J., E-mail: R.A.J.Nievelstein@umcutrecht.n [Department of Radiology, University Medical Center Utrecht, Utrecht (Netherlands); Poulus, M., E-mail: M.Poulus@amc.uva.n [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Thomassen-de Graaf, M.A., E-mail: TomassenM@zgv.n [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Montauban van Swijndregt, A.D., E-mail: A.D.MontaubanvanSwijndregt@olvg.n [Department of Radiology, Onze Lieve Vrouwe Gasthuis, Amsterdam (Netherlands); Stoker, J., E-mail: j.stoker@amc.uva.n [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands)

    2010-08-15

    Purpose: To evaluate the diagnostic performance of radiographers compared to radiologists in the detection of colorectal lesions in MR colonography. Material and methods: 159 patients at increased risk of colorectal cancer were included. Four different experienced observers, one MR radiologist, one radiologist in training and two radiographers evaluated all MR colonography examinations. The protocol included T1-weighted and T2-weighted sequences in prone and supine position. Colonoscopy was used as reference standard. Mean sensitivity rates with 95% confidence intervals (CIs) were determined on a per-patient and per-polyp basis, segmented by size ({>=}6 mm and {>=}10 mm). Specificity was calculated on a per-patient basis. The McNemar and chi-square ({chi}{sup 2}) test was used to determine significant differences. Results: At colonoscopy 74 patients (47%) had normal findings; 23 patients had 40 polyps with a size {>=}6 mm. In 10 patients at least 1 polyp {>=}10 mm was found (20 polyps in total). Similar sensitivities for patients with lesions {>=}10 mm were found for radiologists and radiographers (65% (95%CI: 44-86%) vs. 50% (95%CI: 28-72%)) (p = n.s.). For lesions {>=}10 mm combined per-patient specificity for radiologists and radiographers was 96% (95%CI: 94-98%) and 73% (95%CI: 68-79%) (p < 0.0001). Combined per-patient sensitivity for lesions {>=}6 mm differed significantly between both groups of observers (57% (95%CI: 42-71%) vs. 33% (95%CI: 19-46%)) (p = 0.03). Conclusion: Radiographers have comparable sensitivity but lower specificity relative to radiologists in the detection of colorectal lesions {>=}10 mm at MR colonography. Adequate training in evaluating MR colonography is necessary, especially for readers with no prior experience with colonography.

  18. A randomised, multicentre clinical trial of specialised palliative care plus standard treatment versus standard treatment alone for cancer patients with palliative care needs: the Danish palliative care trial (DanPaCT) protocol

    DEFF Research Database (Denmark)

    Johnsen, Anna Thit; Damkier, Anette; Vejlgaard, Tove Bahn

    2013-01-01

    Advanced cancer patients experience considerable symptoms, problems, and needs. Early referral of these patients to specialised palliative care (SPC) could improve their symptoms and problems.The Danish Palliative Care Trial (DanPaCT) investigates whether patients with metastatic cancer, who report...

  19. Comparison of Iohexol-380 and Iohexol-350 for coronary CT angiography: A multicenter, randomized, double-blind phase 3 trial

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun Ah; Lee, Whal [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Kang, Doo Kyoung [Dept. of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of); and others

    2016-06-15

    This multi-center, randomized, double-blind, phase 3 trial was conducted to compare the safety and efficacy of contrast agents iohexol-380 and iohexol-350 for coronary CT angiography in healthy subjects. Volunteers were randomized to receive 420 mgI/kg of either iohexol-350 or iohexol-380 using a flow rate of 4 mL/sec. All adverse events were recorded. Two blinded readers independently reviewed the CT images and conflicting results were resolved by a third reader. Luminal attenuations (ascending aorta, left main coronary artery, and left ventricle) in Hounsfield units (HUs) and image quality on a 4-point scale were calculated. A total of 225 subjects were given contrast media (115 with iohexol-380 and 110 with iohexol-350). There was no difference in number of adverse drug reactions between groups: 75 events in 56 (48.7%) of 115 subjects in the iohexol-380 group vs. 74 events in 51 (46.4%) of 110 subjects in the iohexol-350 group (p = 0.690). No severe adverse drug reactions were recorded. Neither group showed an increase in serum creatinine. Significant differences in mean density between the groups was found in the ascending aorta: 375.8 ± 71.4 HU with iohexol-380 vs. 356.3 ± 61.5 HU with iohexol-350 (p = 0.030). No significant differences in image quality scores between both groups were observed for all three anatomic evaluations (all, p > 0.05). Iohexol-380 provides improved enhancement of the ascending aorta and similar attenuation of the coronary arteries without any increase in adverse drug reactions, as compared with iohexol-350 using an identical amount of total iodine.

  20. Ankles back in randomized controlled trial (ABrCt: braces versus neuromuscular exercises for the secondary prevention of ankle sprains. Design of a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Verhagen Evert ALM

    2011-09-01

    Full Text Available Abstract Background Ankle sprains are the most common sports and physical activity related injury. There is extensive evidence that there is a twofold increased risk for injury recurrence for at least one year post injury. In up to 50% of all cases recurrences result in disability and lead to chronic pain or instability, requiring prolonged medical care. Therefore ankle sprain recurrence prevention in athletes is essential. This RCT evaluates the effect of the combined use of braces and neuromuscular training (e.g. proprioceptive training/sensorimotor training/balance training against the individual use of either braces or neuromuscular training alone on ankle sprain recurrences, when applied to individual athletes after usual care. Methods/Design This study was designed as three way randomized controlled trial with one year follow-up. Healthy individuals between 12 and 70 years of age, who were actively participating in sports and who had sustained a lateral ankle sprain in the two months prior to inclusion, were eligible for inclusion. After subjects had finished ankle sprain treatment by means of usual care, they were randomised to any of the three study groups. Subjects in group 1 received an eight week neuromuscular training program, subjects in group 2 received a sports brace to be worn during all sports activities for the duration of one year, and group 3 received a combination of the neuromuscular training program and a sports brace to be worn during all sports activities for the duration of eight weeks. Outcomes were assessed at baseline and every month for 12 months therafter. The primary outcome measure was incidence of ankle sprain recurrences. Secondary outcome measures included the direct and indirect costs of recurrent injury, the severity of recurrent injury, and the residual complaints during and after the intervention. Discussion The ABrCt is the first randomized controlled trial to directly compare the secondary preventive

  1. Comparative accuracy of CT perfusion in diagnosing acute ischemic stroke: A systematic review of 27 trials.

    Science.gov (United States)

    Shen, Jiantong; Li, Xianglian; Li, Youping; Wu, Bing

    2017-01-01

    To systematically evaluate and compare the diagnostic accuracy of CT perfusion (CTP), non-enhanced computed tomography (NCCT) and computed tomography angiography (CTA) in detecting acute ischemic stroke. We searched seven databases and screened the reference lists of the included studies. The risk of bias in the study quality was assessed using QUADASII. We produced paired forest plots in RevMan to show the variation of the sensitivity and specificity estimates together with their 95% CI. We used a hierarchical summary ROC model to summarize the sensitivity and specificity of CTP in detecting ischemic stroke. We identified 27 studies with a total of 2168 patients. The pooled sensitivity of CTP for acute ischemic stroke was 82% (95% CI 75-88%), and the specificity was 96% (95% CI 89-99%). CTP was more sensitive than NCCT and had a similar accuracy with CTA. There were no statistically significant differences in the sensitivity and specificity between patients who underwent CTP within 6 hours of symptom onset and beyond 6 hours after symptom onset. No adverse events were reported in the included studies. CTP is more accurate than NCCT and has similar accuracy to CTA in detecting acute ischemic stroke. However, the evidence is not strong. There is potential benefit of using CTP to select stroke patients for treatment, but more high-quality evidence is needed to confirm this result.

  2. Predictors of incomplete optical colonoscopy using computed tomographic colonography

    Directory of Open Access Journals (Sweden)

    Reetika Sachdeva

    2016-01-01

    Full Text Available Background/Aims: Optical colonoscopy (OC is the primary modality for investigation of colonic pathology. Although there is data on demographic factors for incomplete OC, paucity of data exists for anatomic variables that are associated with an incomplete OC. These anatomic variables can be visualized using computed tomographic colonography (CTC. We aim to retrospectively identify variables associated with incomplete OC using CTC and develop a scoring method to predict the outcome of OC. Patients and Methods: In this case-control study, 70 cases ( with incomplete OC and 70 controls (with complete OC were identified. CTC images of cases and controls were independently reviewed by a single CTC radiologist. Demographic and anatomical parameters were recorded. Data was examined using descriptive linear statistics and multivariate logistic regression model. Results: On analysis, female gender (80% vs 58.6% P = 0.007, prior abdominal/pelvic surgeries (51.4% vs 14.3% P < 0.001, colonic length (187.6 ± 30.0 cm vs 163.8 ± 27.2 cm P < 0.001, and number of flexures (11.4 ± 3.1 vs 8.4 ± 2.9 P < 0.001 increased the risk for incomplete OC. No significant association was observed for increasing age (P = 0.881 and history of severe diverticulosis (P = 0.867 with incomplete OC. A scoring system to predict the outcome of OC is proposed based on CTC findings. Conclusion: Female gender, prior surgery, and increasing colonic length and tortuosity were associated with incomplete OC, whereas increasing age and history of severe diverticulosis were not. These factors may be used in the future to predict those patients who are at risk of incomplete OC.

  3. A multicenter, randomized controlled trial of immediate total-body CT scanning in trauma patients (REACT-2).

    NARCIS (Netherlands)

    Sierink, J.C.; Saltzherr, T.P.; Beenen, L.F.; Luitse, J.S.; Hollmann, M.W.; Reitsma, J.B.; Edwards, M.J.R.; Hohmann, J.; Beuker, B.J.; Patka, P.; Suliburk, J.W.; Dijkgraaf, M.G.; Goslings, J.C.

    2012-01-01

    BACKGROUND: Computed tomography (CT) scanning has become essential in the early diagnostic phase of trauma care because of its high diagnostic accuracy. The introduction of multi-slice CT scanners and infrastructural improvements made total-body CT scanning technically feasible and its usage is curr

  4. A multicenter, randomized controlled trial of immediate total-body CT scanning in trauma patients (REACT-2)

    NARCIS (Netherlands)

    J.C. Sierink (Joanne); T.P. Saltzherr (Teun); L.F.M. Beenen (Ludo); J.S.K. Luitse; M.W. Hollmann (Markus); J.B. Reitsma (Johannes); M.J.R. Edwards (Michael); J. Hohmann (Joachim); B.J.A. Beuker (Benn); P. Patka (Peter); J.W. Suliburk (James); M.G.W. Dijkgraaf (Marcel); J.C. Goslings (Carel)

    2012-01-01

    textabstractBackground: Computed tomography (CT) scanning has become essential in the early diagnostic phase of trauma care because of its high diagnostic accuracy. The introduction of multi-slice CT scanners and infrastructural improvements made total-body CT scanning technically feasible and its u

  5. QUALITY ASSURANCE OF 4D-CT SCAN TECHNIQUES IN MULTICENTER PHASE III TRIAL OF SURGERY VERSUS STEREOTACTIC RADIOTHERAPY (RADIOSURGERY OR SURGERY FOR OPERABLE EARLY STAGE (STAGE 1A) NON-SMALL-CELL LUNG CANCER [ROSEL] STUDY)

    NARCIS (Netherlands)

    Hurkmans, Coen W.; van Lieshout, Maarten; Schuring, Danny; van Heumen, Marielle J. T.; Cuijpers, Johan P.; Lagerwaard, Frank J.; Widder, Joachim; van der Heide, Uulke A.; Senan, Suresh

    2011-01-01

    Purpose: To determine the accuracy of four-dimensional computed tomography (4D-CT) scanning techniques in institutions participating in a Phase III trial of surgery vs. stereotactic radiotherapy (SBRT) for lung cancer. Methods and Materials: All 9 centers performed a 4D-CT scan of a motion phantom (

  6. Colovesical fistula causing an uncommon reason for failure of computed tomography colonography: a case report

    OpenAIRE

    2012-01-01

    Abstract Introduction Computed tomography colonography, or virtual colonoscopy, is a good alternative to optical colonoscopy. However, suboptimal patient preparation or colon distension may reduce the diagnostic accuracy of this imaging technique. Case presentation We report the case of an 83-year-old Caucasian woman who presented with a five-month history of pneumaturia and fecaluria and an acute episode of macrohematuria, leading to a high clinical suspicion of a colovesical fistula. The fi...

  7. Magnetic resonance colonography with automated carbon dioxide insufflation: Diagnostic accuracy and distension

    Energy Technology Data Exchange (ETDEWEB)

    Paardt, M.P. van der, E-mail: m.p.vanderpaardt@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Zijta, F.M., E-mail: fmzijta@yahoo.com [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Department of Radiology, Onze Lieve Vrouwe Gasthuis, Amsterdam (Netherlands); Department of Radiology, Medisch Centrum Haaglanden, Den Haag (Netherlands); Boellaard, T.N., E-mail: t.n.boellaard@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Jensch, S., E-mail: s.jensch@slaz.nl [Department of Radiology, Sint Lucas-Andreas Ziekenhuis, Amsterdam (Netherlands); Baak, L.C., E-mail: l.c.baak@olvg.nl [Department of Gastroenterology and Hepatology, Onze Lieve Vrouwe Gasthuis, Amsterdam (Netherlands); Depla, A.C.T.M., E-mail: actm.depla@slz.nl [Department of Gastroenterology and Hepatology, Slotervaartziekenhuis, Amsterdam (Netherlands); Dekker, E., E-mail: e.dekker@amc.uva.nl [Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Nederveen, A.J., E-mail: a.j.nederveen@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Bipat, S., E-mail: s.bipat@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Stoker, J., E-mail: j.stoker@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands)

    2014-05-15

    Objectives: To evaluate the diagnostic performance of MR colonography using automated carbon dioxide (CO{sub 2}) insufflation for colonic distension, with colonoscopy serving as the reference standard. Methods: Ninety-eight symptomatic patients underwent MR colonography with faecal tagging and automated CO{sub 2} insufflation. Three readers (one expert (reader 1), and two less experienced (readers 2 and 3)) evaluated the images for the presence of colorectal lesions. Bowel distension was evaluated on a 4-point scale. Results were verified with colonoscopy and histopathological analysis. Results: Per-patient sensitivity for lesions ≥10 mm was 91.7% (11 of 12) (reader 1), 75.0% (9 of 12) (reader 2), and 75% (9 of 12) (reader 3). Specificity was 96.5% (82 of 85) (reader 1), 97.7% (83 of 85) (reader 2), 95.3% (81 of 85) (reader 3). Per-patient sensitivity for lesions ≥6 mm was 85.7% (18 of 21) (reader 1), 57.1% (12 of 21) (reader 2), and 57.1% (12 of 21) (reader 3). Specificity was 86.8% (66 of 76), 98.7% (75 of 76), 90.8% (69 of 76), respectively. Per-patient sensitivity for advanced neoplasia of ≥10 mm and ≥6 mm was 88.9% (8 of 9) for all readers. Specificity for ≥10 mm and ≥6 mm was 98.9% (87 of 88) (reader 1), 97.7% (86 of 88) (reader 2), 96.6% (85 of 88) (reader 3). 94.4% of the colon segments were adequate to optimal distended with dual positioning. Conclusion: MR colonography can accurately detect lesions ≥10 mm, and advanced neoplasia ≥6 mm. Sufficient distension was achieved using automated CO{sub 2} insufflation for colonic distension in MR colonography.

  8. Magnetic resonance (MR) colonography in the detection of colorectal lesions: a systematic review of prospective studies

    Energy Technology Data Exchange (ETDEWEB)

    Zijta, Frank M. [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Academic Medical Centre, Amsterdam (Netherlands); Bipat, Shandra; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands)

    2010-05-15

    To determine the diagnostic accuracy of MR-colonography for the detection of colorectal lesions. A comprehensive literature search was performed for comparative MR-colonography studies, published between May 1997 and February 2009, using the MEDLINE, EMBASE and Cochrane databases. We included studies if MR-colonography findings were prospectively compared with conventional colonoscopy in (a)symptomatic patients. Two reviewers independently extracted study design characteristics and data for summarising sensitivity and specificity. Heterogeneity in findings between studies was tested using I{sup 2} test statistics. Sensitivity and specificity estimates with 95% confidence intervals (CI) were calculated on per patient basis and summary sensitivity on per polyp basis, using bivariate and univariate statistical models. Thirty-seven studies were found to be potentially relevant and 13 fulfilled the inclusion criteria. The study population comprised 1,285 patients with a mean disease prevalence of 44% (range 22-63%). Sensitivity for the detection of CRC was 100%. Significant heterogeneity was found for overall per patient sensitivity and specificity. For polyps with a size of 10 mm or larger, per patient sensitivity and specificity estimates were 88% (95% CI 63-97%; I{sup 2} = 37%) and 99% (95% CI 95-100%; I {sup 2} = 60%). On a per polyp basis, polyps of 10 mm or larger were detected with a sensitivity of 84% (95% CI 66-94%; I {sup 2} = 51%). The data were too heterogeneous for polyps smaller than 6 mm and 6-9 mm. MR-colonography can accurately detect colorectal polyps more than 10 mm in size. (orig.)

  9. Observer reliability of CT angiography in the assessment of acute ischaemic stroke: data from the Third International Stroke Trial

    Energy Technology Data Exchange (ETDEWEB)

    Mair, Grant; Farrall, Andrew J.; Sellar, Robin J.; Mollison, Daisy; Sakka, Eleni; Palmer, Jeb; Wardlaw, Joanna M. [University of Edinburgh, Western General Hospital, Division of Neuroimaging Sciences, Edinburgh (United Kingdom); Kummer, Ruediger von [Dresden University Stroke Centre, University Hospital, Department of Neuroradiology, Dresden (Germany); Adami, Alessandro [Sacro Cuore-Don Calabria Hospital, Stroke Center, Department of Neurology, Negrar (Italy); White, Philip M. [Stroke Research Group, Newcastle upon Tyne (United Kingdom); Adams, Matthew E. [National Hospital for Neurology and Neurosurgery, Department of Neuroradiology, London (United Kingdom); Yan, Bernard [Royal Melbourne Hospital, Neurovascular Research Group, Parkville (Australia); Demchuk, Andrew M. [Calgary Stroke Program, Department of Clinical Neurosciences, Calgary (Canada); Ramaswamy, Rajesh; Rodrigues, Mark A.; Samji, Karim; Baird, Andrew J. [Royal Infirmary of Edinburgh, Department of Radiology, Edinburgh (United Kingdom); Boyd, Elena V. [Northwick Park Hospital, Department of Radiology, Harrow (United Kingdom); Cohen, Geoff; Perry, David; Sandercock, Peter A.G. [University of Edinburgh, Western General Hospital, Division of Clinical Neurosciences, Edinburgh (United Kingdom); Lindley, Richard [University of Sydney, Westmead Hospital Clinical School and The George Institute for Global Health, Sydney (Australia); Collaboration: The IST-3 Collaborative Group

    2014-10-07

    CT angiography (CTA) is often used for assessing patients with acute ischaemic stroke. Only limited observer reliability data exist. We tested inter- and intra-observer reliability for the assessment of CTA in acute ischaemic stroke. We selected 15 cases from the Third International Stroke Trial (IST-3, ISRCTN25765518) with various degrees of arterial obstruction in different intracranial locations on CTA. To assess inter-observer reliability, seven members of the IST-3 expert image reading panel (>5 years experience reading CTA) and seven radiology trainees (<2 years experience) rated all 15 scans independently and blind to clinical data for: presence (versus absence) of any intracranial arterial abnormality (stenosis or occlusion), severity of arterial abnormality using relevant scales (IST-3 angiography score, Thrombolysis in Cerebral Infarction (TICI) score, Clot Burden Score), collateral supply and visibility of a perfusion defect on CTA source images (CTA-SI). Intra-observer reliability was assessed using independently repeated expert panel scan ratings. We assessed observer agreement with Krippendorff's-alpha (K-alpha). Among experienced observers, inter-observer agreement was substantial for the identification of any angiographic abnormality (K-alpha = 0.70) and with an angiography assessment scale (K-alpha = 0.60-0.66). There was less agreement for grades of collateral supply (K-alpha = 0.56) or for identification of a perfusion defect on CTA-SI (K-alpha = 0.32). Radiology trainees performed as well as expert readers when additional training was undertaken (neuroradiology specialist trainees). Intra-observer agreement among experts provided similar results (K-alpha = 0.33-0.72). For most imaging characteristics assessed, CTA has moderate to substantial observer agreement in acute ischaemic stroke. Experienced readers and those with specialist training perform best. (orig.)

  10. Magnetic resonance colonography with a limited bowel preparation and automated carbon dioxide insufflation in comparison to conventional colonoscopy: Patient burden and preferences

    Energy Technology Data Exchange (ETDEWEB)

    Paardt, M.P. van der, E-mail: m.p.vanderpaardt@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Boellaard, T.N., E-mail: t.n.boellaard@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Zijta, F.M., E-mail: fmzijta@yahoo.com [Department of Radiology, Medisch Centrum Haaglanden, Den Haag (Netherlands); Baak, L.C., E-mail: l.c.baak@olvg.nl [Department of Gastroenterology and Hepatology, Onze Lieve Vrouwe Gasthuis, Amsterdam (Netherlands); Depla, A.C.T.M., E-mail: actm.depla@slz.nl [Department of Gastroenterology and Hepatology, Slotervaartziekenhuis, Amsterdam (Netherlands); Dekker, E., E-mail: e.dekker@amc.uva.nl [Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Nederveen, A.J., E-mail: a.j.nederveen@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Bipat, S., E-mail: s.bipat@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Stoker, J., E-mail: j.stoker@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands)

    2015-01-15

    Highlights: • MR colonography with a limited bowel preparation and automated carbon dioxide insufflation demonstrated less burden compared to colonoscopy. • When discarding the bowel preparation, the examinations were rated equally burdensome. • The majority of patients preferred MR colonography over colonoscopy for their future examination of the bowel. - Abstract: Objectives: To evaluate patient burden and preferences for MR colonography with a limited bowel preparation and automated carbon dioxide insufflation in comparison to conventional colonoscopy. Methods: Symptomatic patients were consecutively recruited to undergo MR colonography with automated carbon dioxide insufflation and a limited bowel preparation followed within four weeks by colonoscopy with a standard bowel cleansing preparation. Four questionnaires regarding burden (on a five-point scale) and preferences (on a seven-point scale) were addressed after MR colonography and colonoscopy and five weeks after colonoscopy. Results: Ninety-nine patients (47 men, 52 women; mean age 62.3, SD 8.7) were included. None of the patients experienced severe or extreme burden from the MR colonography bowel preparation compared to 31.5% of the patients for the colonoscopy bowel preparation. Colonoscopy was rated more burdensome (25.6% severe or extreme burden) compared to MR colonography (5.2% severe or extreme burden) (P < 0.0001). When discarding the bowel preparations, the examinations were rated equally burdensome (P = 0.35). The majority of patients (61.4%) preferred MR colonography compared to colonoscopy (29.5%) immediately after the examinations and five weeks later (57.0% versus 39.5%). Conclusion: MR colonography with a limited bowel preparation and automated carbon dioxide insufflation demonstrated less burden compared to colonoscopy. The majority of patients preferred MR colonography over colonoscopy.

  11. Extracolonic Findings on CT Colonography Increases Yield of Colorectal Cancer Screening

    Science.gov (United States)

    2010-09-01

    gallstones; hiatal hernia E3 Likely unimportant finding, incompletely characterized: workup may be indicated Complex renal cyst; lung nodule E4...of which were renal cysts, neph­ rolithiasis, hiatal hernias , or benign liver cysts. The majority of findings for patients in the E3 group (n = 211...costs and studies generated. In addition, following patients out to their final diagnosis and, especially , establishing histologic diagno­ ses for

  12. Effect of a tele-training programme on radiographers in the interpretation of CT colonography

    DEFF Research Database (Denmark)

    Lauridsen, Carsten; Lefere, Philippe; Gerke, Oke;

    2012-01-01

    (95% CI). The results were compared by comparing 95% CI with a 5% significance level. RESULTS: In the training cases overall per-polyp sensitivity was 57% (95% CI 46.1-67.9) and 69.1% (95% CI 50.6-87.5) for lesions ≥6mm and ≥10mm, respectively. Overall per patient sensitivity, specificity and PPV were...

  13. Increasing computer-aided detection specificity by projection features for CT colonography

    OpenAIRE

    Zhu, Hongbin; Liang, Zhengrong; Pickhardt, Perry J.; Barish, Matthew A.; You, Jiangsheng; Fan, Yi; Lu, Hongbing; Posniak, Erica J.; Richards, Robert J.; Cohen, Harris L.

    2010-01-01

    Purpose: A large number of false positives (FPs) generated by computer-aided detection (CAD) schemes is likely to distract radiologists’ attention and decrease their interpretation efficiency. This study aims to develop projection-based features which characterize true and false positives to increase the specificity while maintaining high sensitivity in detecting colonic polyps.

  14. Ascending colon rotation following patient positional change during CT colonography: a potential pitfall in interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Yeon; Park, Seong Ho; Lee, Seung Soo; Kim, Ah Young; Ha, Hyun Kwon [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of)

    2011-02-15

    To investigate the degree and pattern of ascending colonic rotation as patients moved from supine to prone positions during CTC. A search of our CTC and colonoscopy database found 37 patients (43 eligible lesions) who fulfilled the following criteria: colonoscopy-proven sessile polyps {>=}6 mm in the straight mid-ascending colon, lesion visualisation in both supine and prone CTC, and optimal colonic distension. A coordinate system was developed to designate the polyp radial location ( ) along the luminal circumference, unaffected by rotation of the torso. The degree/direction of polyp radial location change (i.e. ascending colonic rotation) between supine and prone positions correlated with anthropometric measurements. Movement from supine to prone positions resulted in a change in the radial polyp location of between -23 and 79 (median, 21 ), demonstrating external rotation of the ascending colon in almost all cases (2 to 79 in 36/37 patients and 42/43 lesions). The degree/direction of rotation mildly correlated with the degree of abdominal compression in the anterior-posterior direction in prone position (r = 0.427 [P = 0.004] and r = 0.404 [P = 0.007]). The ascending colon was usually found to rotate externally as patients moved from supine to prone positions, partly dependent on the degree of abdominal compression. (orig.)

  15. Eigenvalue-weighting and feature selection for computer-aided polyp detection in CT colonography

    Science.gov (United States)

    Zhu, Hongbin; Wang, Su; Fan, Yi; Lu, Hongbing; Liang, Zhengrong

    2010-03-01

    With the development of computer-aided polyp detection towards virtual colonoscopy screening, the trade-off between detection sensitivity and specificity has gained increasing attention. An optimum detection, with least number of false positives and highest true positive rate, is desirable and involves interdisciplinary knowledge, such as feature extraction, feature selection as well as machine learning. Toward that goal, various geometrical and textural features, associated with each suspicious polyp candidate, have been individually extracted and stacked together as a feature vector. However, directly inputting these high-dimensional feature vectors into a learning machine, e.g., neural network, for polyp detection may introduce redundant information due to feature correlation and induce the curse of dimensionality. In this paper, we explored an indispensable building block of computer-aided polyp detection, i.e., principal component analysis (PCA)-weighted feature selection for neural network classifier of true and false positives. The major concepts proposed in this paper include (1) the use of PCA to reduce the feature correlation, (2) the scheme of adaptively weighting each principal component (PC) by the associated eigenvalue, and (3) the selection of feature combinations via the genetic algorithm. As such, the eigenvalue is also taken as part of the characterizing feature, and the necessary number of features can be exposed to mitigate the curse of dimensionality. Learned and tested by radial basis neural network, the proposed computer-aided polyp detection has achieved 95% sensitivity at a cost of average 2.99 false positives per polyp.

  16. Impact of morphine use in reducing the need for CT scan in patients with cervical spine trauma: a double blinded randomized clinical trial

    Science.gov (United States)

    Sharifi, Mohammad Davood; Doloo, Hamid Zamani Moghadam; Hashemian, Amir Masoud; Tourghabe, Javad Tootian; Kakhki, Behrang Rezvani; Teimoori, Sasan Johari; Chokan, Niaz Mohammad Jafari; Noroozi, Hamid Reza

    2016-01-01

    Background Cervical spine trauma occurs mostly among young males due to falls and car accidents. The CT scan technology is replacing radiography in many medical clinics as it is very capable in detecting subtle cervical spine injuries. However, the use of CT scan for routine screening in patients with cervical spine trauma remains controversial due to its radiation risks and relatively high cost. Objective The focus of this research was on using morphine in patients with cervical spine trauma. The objective was to determine the ability of morphine to reduce the number of patients in need of CT scans. Methods This double-blinded randomized clinical trial study was conducted from April 2014 to March 2015 in Hasheminejad Hospital in Mashhad, Iran. We enrolled 67 patients with cervical spine trauma and normal radiography in the study. They were divided randomly into two groups (groups A and B), where group A received intravenous morphine, and group B received a placebo. We measured the pain scores in both groups before giving the medication and 10 minutes afterwards using a visual analog scale (VAS). Results As a result of receiving morphine, the patients in group A had significantly lower pain than group B (p-value < 0.001). The average pain score in group A was reduced by 43% versus 23% in group B. However, the most pain reduction was in those in group A with a normal CT scan. The pain score of these patients dropped by 52%. Conclusions The findings of this study suggest that patients with a normal radiography may be discharged with a cervical collar without a need for a CT scan if morphine reduces their pain. This is because the pain in these patients stem from the muscles and non-bony structures in the cervical spine area. Clinical trial registration: The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the IRCT ID: IRCT2013100214872N1 Funding The authors received no financial support for the research or for the publication

  17. A new liposomal liver-specific contrast agent for CT: first human phase-I clinical trial assessing efficacy and safety

    Energy Technology Data Exchange (ETDEWEB)

    Leander, P. [Dept. of Diagnostic Radiology, Malmoe University Hospital (Sweden); Hoeglund, P. [Dept. of Clinical Pharmacology, Lund University Hospital (Sweden); Boerseth, A.; Kloster, Y.; Berg, A. [Nycomed Amersham Imaging, Oslo (Norway)

    2001-04-01

    In this first clinical trial liposome-encapsulated iodixanol, CT particles (CTP) were studied. The aims of the present trial were to assess the efficacy of CTP in CT and to determine the safety of different doses of CTP. A total of 47 healthy volunteers were enrolled in the present study. The CTP was administered at doses 10, 30, 70 and 100 mg encapsulated I/kg bw. Efficacy was assessed using single-slice CT of the abdomen and evaluated by dose-response attenuation curves over time in liver, spleen, and abdominal vessels. Safety was assessed by blood tests, clinical examinations and recording of subjective adverse events (AE). The attenuations in liver tissue increased with the dose and maximal values above baseline were 20, 39 and 45 HU at the doses 30, 70 and 100 mg encapsulated I/kg bw, respectively. Maximal increases were seen 12.5 min after contrast administration. As for liver, the attenuations in spleen increased with the dose, but higher attenuations were obtained. In early images clinically significant enhancement was seen in abdominal vessels. Mild and moderate subjective AE were encountered at the doses 70 and 100 mg encapsulated I/kg bw. The CTP is efficacious in enhancing hepatic and splenic tissues and in early imaging of abdominal vessels. Adverse event precludes a clinical use of CTP in the current formulation. (orig.)

  18. Preoperative CT versus diffusion weighted magnetic resonance imaging of the liver in patients with rectal cancer; a prospective randomized trial

    Directory of Open Access Journals (Sweden)

    Michael P. Achiam

    2016-01-01

    Full Text Available Introduction. Colorectal cancer is one of the most frequent cancers in the world and liver metastases are seen in up to 19% of patients with colorectal cancers. Detection of liver metastases is not only vital for sufficient treatment and survival, but also for a better estimation of prognosis. The aim of this study was to evaluate the feasibility of diffusion weighted MRI of the liver as part of a combined MR evaluation of patients with rectal cancers and compare it with the standard preoperative evaluation of the liver with CT.Methods. Consecutive patients diagnosed with rectal cancers were asked to participate in the study. Preoperative CT and diffusion weighted MR (DWMR were compared to contrast enhanced laparoscopic ultrasound (CELUS.Results. A total of 35 patients were included, 15 patients in Group-1 having the standard CT evaluation of the liver and 20 patients in Group-2 having the standard CT evaluation of the liver and DWMR of the liver. Compared with CELUS, the per-patient sensitivity/specificity was 50/100% for CT, and for DWMR: 100/94% and 100/100% for Reader 1 and 2, respectively. The per-lesion sensitivity of CT and DWMR were 17% and 89%, respectively compared with CELUS. Furthermore, one patient had non-resectable metastases after DWMR despite being diagnosed with resectable metastases after CT. Another patient was diagnosed with multiple liver metastases during CELUS, despite a negative CT-scan.Discussion. DWMR is feasible for preoperative evaluation of liver metastases. The current standard preoperative evaluation with CT-scan results in disadvantages like missed metastases and futile operations. We recommend that patients with rectal cancer, who are scheduled for MR of the rectum, should have a DWMR of the liver performed at the same time.

  19. Differentiation between benign and malignant colon tumors using fast dynamic gadolinium-enhanced MR colonography; a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Achiam, M.P., E-mail: achiam1@dadlnet.d [Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Diagnostic Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3C, DK-2200 Copenhagen (Denmark); Andersen, L.P.H.; Klein, M. [Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Diagnostic Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3C, DK-2200 Copenhagen (Denmark); Logager, V.; Chabanova, E.; Thomsen, H.S. [Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Diagnostic Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3C, DK-2200 Copenhagen (Denmark); Rosenberg, J. [Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark); Department of Diagnostic Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3C, DK-2200 Copenhagen (Denmark)

    2010-06-15

    Background: Colorectal cancer will present itself as a bowel obstruction in 16-23% of all cases. However, not all obstructing tumors are malignant and the differentiation between a benign and a malignant tumor can be difficult. The purpose of our study was to determine whether fast dynamic gadolinium-enhanced MR imaging combined with MR colonography could be used to differentiate a benign from a malignant obstructing colon tumor. Methods: Patients with benign colon tumor stenosis, based on diverticulitis, were asked to participate in the study. The same number of patients with verified colorectal cancer was included. Both groups had to be scheduled for surgery to be included. Two blinded observers analyzed the tumors on MR by placing a region of interest in the tumor and a series of parameters were evaluated, e.g. wash-in, wash-out and time-to-peak. Results: 14 patients were included. The wash-in and wash-out rates were significantly different between the benign and malignant tumors, and a clear distinction between benign and malignant disease was therefore possible by looking only at the MR data. Furthermore, MR colography evaluating the rest of the colon past the stenosis was possible with all patients. Conclusion: The results showed the feasibility of using fast dynamic gadolinium-enhanced MR imaging to differentiate between benign and malignant colonic tumors. With a high intra-class correlation and significant differences found on independent segments of the tumor, the method appears to be reproducible. Furthermore, the potential is big in performing a full preoperative colon evaluation even in patients with obstructing cancer. Trial number: (NCT00114829).

  20. Detection of colorectal liver metastases: a prospective multicenter trial comparing unenhanced MRI, MnDPDP-enhanced MRI, and spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Bartolozzi, Carlo; Donati, Francescamaria; Cioni, Dania; Lencioni, Riccardo [Department of Radiology, University of Pisa, Via Roma 67, 56100, Pisa (Italy); Procacci, Carlo; Morana, Giovanni [Department of Radiology, University of Verona, Piazzale L.A. Scuro 1, 37134, Verona (Italy); Chiesa, Antonio; Grazioli, Luigi [Department of Radiology, University of Brescia, Piazzale Spedali Civili 1, 25023, Brescia (Italy); Cittadini, Giorgio; Cittadini, Giuseppe [Department of Radiology, University of Genova, Largo R. Benzi 10, 16132, Genova (Italy); Giovagnoni, Andrea [Department of Radiology, University of Ancona, Concam, Torrette, 60020, Ancona (Italy); Gandini, Giovanni; Maass, Jochen [Department of Radiology, University of Torino, Genova 3, 10110, Torino (Italy)

    2004-01-01

    The aim of this study was to compare unenhanced MRI, MnDPDP-enhanced MRI, and spiral CT in the detection of hepatic colorectal metastases. Forty-four patients with hepatic colorectal metastases were examined with unenhanced and MnDPDP-enhanced MRI and with unenhanced and contrast-enhanced spiral CT. The MR examination protocol included baseline T1-weighted spin-echo (SE), T1-weighted gradient-recalled-echo (GRE), and T2-weighted fast-SE sequences; and T1-weighted SE and T1-weighted GRE sequences obtained 30-60 min after administration of 0.5 {mu}mol/kg (0.5 ml/kg) mangafodipir trisodium (MnDPDP). Images were interpreted by three blinded readers. Findings at CT and MRI were compared with those at intraoperative US, which were used as term of reference. Intraoperative US detected 128 metastases. In a lesion-by-lesion analysis, the overall detection rate was 71% (91 of 128) for spiral CT, 72% (92 of 128) for unenhanced MRI, and 90% (115 of 128) for MnDPDP-enhanced MRI. MnDPDP-enhanced MRI was more sensitive than either unenhanced MRI (p<0.0001) or spiral CT (p=0.0007). In a patient-by-patient analysis, agreement with gold standard was higher for MnDPDP-enhanced MRI (33 of 44 cases) than for spiral CT (22 of 44 cases, p=0.0023) and unenhanced MRI (21 of 44 cases, p=0.0013). MnDPDP-enhanced MRI is superior to unenhanced MRI and spiral CT in the detection of hepatic colorectal metastases. (orig.)

  1. Lung cancer incidence and mortality in National Lung Screening Trial participants who underwent low-dose CT prevalence screening: a retrospective cohort analysis of a randomised, multicentre, diagnostic screening trial

    Science.gov (United States)

    Patz, Edward F; Greco, Erin; Gatsonis, Constantine; Pinsky, Paul; Kramer, Barnett S; Aberle, Denise R

    2016-01-01

    Summary Background Annual low-dose CT screening for lung cancer has been recommended for high-risk individuals, but the necessity of yearly low-dose CT in all eligible individuals is uncertain. This study examined rates of lung cancer in National Lung Screening Trial (NLST) participants who had a negative prevalence (initial) low-dose CT screen to explore whether less frequent screening could be justified in some lower-risk subpopulations. Methods We did a retrospective cohort analysis of data from the NLST, a randomised, multicentre screening trial comparing three annual low-dose CT assessments with three annual chest radiographs for the early detection of lung cancer in high-risk, eligible individuals (aged 55–74 years with at least a 30 pack-year history of cigarette smoking, and, if a former smoker, had quit within the past 15 years), recruited from US medical centres between Aug 5, 2002, and April 26, 2004. Participants were followed up for up to 5 years after their last annual screen. For the purposes of this analysis, our cohort consisted of all NLST participants who had received a low-dose CT prevalence (T0) screen. We determined the frequency, stage, histology, study year of diagnosis, and incidence of lung cancer, as well as overall and lung cancer-specific mortality, and whether lung cancers were detected as a result of screening or within 1 year of a negative screen. We also estimated the effect on mortality if the first annual (T1) screen in participants with a negative T0 screen had not been done. The NLST is registered with ClinicalTrials.gov, number NCT00047385. Findings Our cohort consisted of 26 231 participants assigned to the low-dose CT screening group who had undergone their T0 screen. The 19 066 participants with a negative T0 screen had a lower incidence of lung cancer than did all 26 231 T0-screened participants (371·88 [95% CI 337·97–408·26] per 100 000 person-years vs 661·23 [622·07–702·21]) and had lower lung cancer

  2. CT and MRI-based door-needle-times for acute stroke patients a quasi-randomized clinical trial

    DEFF Research Database (Denmark)

    Hansen, Christine Krarup; Christensen, Anders; Rodgers, Helen

    2017-01-01

    OBJECTIVES: Door-Needle-times (DNT) of 20min are feasible when Computer Tomography (CT) is used for first-line brain-imaging to assess stroke-patients' eligibility for intravenous-tissue-Plasminogen-Activator (iv-tPA), but the more time-consuming Magnetic Resonance Imaging (MRI)-based-evaluation ......OBJECTIVES: Door-Needle-times (DNT) of 20min are feasible when Computer Tomography (CT) is used for first-line brain-imaging to assess stroke-patients' eligibility for intravenous-tissue-Plasminogen-Activator (iv-tPA), but the more time-consuming Magnetic Resonance Imaging (MRI...

  3. Evaluation of strategies towards harmonization of FDG PET/CT studies in multicentre trials: comparison of scanner validation phantoms and data analysis procedures

    Energy Technology Data Exchange (ETDEWEB)

    Makris, Nikolaos E.; Huisman, Marc C.; Lammertsma, Adriaan A.; Boellaard, Ronald [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Kinahan, Paul E. [University of Washington, Imaging Research Laboratory, Department of Radiology, Seattle, WA (United States)

    2013-10-15

    PET quantification based on standardized uptake values (SUV) is hampered by several factors, in particular by variability in PET acquisition settings and data analysis methods. Quantitative PET/CT studies acquired during a multicentre trial require harmonization of imaging procedures to maximize study power. The aims of this study were to determine which phantoms are most suitable for detecting differences in image quality and quantification, and which methods for defining volumes of interest (VOI) are least sensitive to these differences. The most common accreditation phantoms used in oncology FDG PET/CT trials were scanned on the same scanner. These phantoms were those used by the Society of Nuclear Medicine Clinical Trials Network (SNM-CTN), the European Association of Nuclear Medicine/National Electrical Manufacturers Association (EANM/NEMA) and the American College of Radiology (ACR). In addition, tumour SUVs were derived from ten oncology whole-body examinations performed on the same PET/CT system. Both phantom and clinical data were reconstructed using different numbers of iterations, subsets and time-of-flight kernel widths. Subsequently, different VOI methods (VOI{sub A50%,} VOI{sub max}, VOI{sub 3Dpeak,} VOI{sub 2Dpeak}) were applied to assess the impact of changes in image reconstruction settings on SUV and recovery coefficients (RC). All phantoms demonstrated sensitivity for detecting changes in SUV and RC measures in response to changes in image reconstruction settings and VOI analysis methods. The SNM-CTN and EANM/NEMA phantoms showed almost equal sensitivity in detecting RC differences with changes in image characteristics. Phantom and clinical data demonstrated that the VOI analysis methods VOI{sub A50%} and VOI{sub max} gave SUV and RC values with large variability in relation to image characteristics, whereas VOI{sub 3Dpeak} and VOI{sub 2Dpeak} were less sensitive to these differences. All three phantoms may be used to harmonize parameters for

  4. Effects of CT dose and nodule characteristics on lung-nodule detectability in a cohort of 90 national lung screening trial patients

    Science.gov (United States)

    Young, Stefano; Lo, Pechin; Hoffman, John M.; Kim, H. J. Grace; Brown, Matthew S.; McNitt-Gray, Michael F.

    2016-03-01

    Lung cancer screening CT is already performed at low dose. There are many techniques to reduce the dose even further, but it is not clear how such techniques will affect nodule detectability. In this work, we used an in-house CAD algorithm to evaluate detectability. 90348 patients and their raw CT data files were drawn from the National Lung Screening Trial (NLST) database. All scans were acquired at ~2 mGy CTDIvol with fixed tube current, 1 mm slice thickness, and B50 reconstruction kernel on a Sensation 64 scanner (Siemens Healthcare). We used the raw CT data to simulate two additional reduced-dose scans for each patient corresponding to 1 mGy (50%) and 0.5 mGy (25%). Radiologists' findings on the NLST reader forms indicated 65 nodules in the cohort, which we subdivided based on LungRADS criteria. For larger category 4 nodules, median sensitivities were 100% at all three dose levels, and mean sensitivity decreased with dose. For smaller nodules meeting the category 2 or 3 criteria, the dose dependence was less obvious. Overall, mean patient-level sensitivity varied from 38.5% at 100% dose to 40.4% at 50% dose, a difference of only 1.9%. However, the false-positive rate quadrupled from 1 per case at 100% dose to 4 per case at 25% dose. Dose reduction affected lung-nodule detectability differently depending on the LungRADS category, and the false-positive rate was very sensitive at sub-screening dose levels. Thus, care should be taken to adapt CAD for the very challenging noise characteristics of screening.

  5. Exploration of cervical carotid stenosis using helical CT angiography. A prospective trial on the detection of candidates for surgery in the Gujo area, Gifu

    Energy Technology Data Exchange (ETDEWEB)

    Yamakawa, Hiroyasu; Sumi, Yasuhiko [Sumi Hospital, Gifu (Japan); Kaku, Yasuhiko; Sakai, Noboru; Yamada, Hiromu

    1995-04-01

    To detect cervical carotid stenosis as a candidate for carotid endarterectomy (CEA), the authors attempted a prospective trial by exploring stenosis for one year in a rural district with a population of 20,000, employing helical CT angiography which apparently displayed three-dimensional reconstructed images of the carotid bifurcation. Thirty-three patients, 24 males and 9 females, with a mean age of 71.8 years, suffering from TIA, RIND or stroke were investigated for their carotid systems. The clinical symptoms of the patients were briefly as follows: motor weakness in 30 cases, dysarthria in 8 cases and aphasia in 4 cases; and 6 of 22 (27%) stroke cases had previously suffered an episode of TIA. The risk factors of the whole group of patients were hypertension in 13 cases, diabetes mellitus in 6, heart disease in 17, and hypercholesteremia in 4. Helical CT angiography was performed in 11 cases of TIA, 2 cases of RIND, and 16 cases of stroke. Only 3 cases of the TIA group and 3 cases of the stroke group were found to have extracranial carotid stenosis of more than 50%, which subsequently required conventional angiography. For the detection of stenosis, CT angiography was beneficial as well as conventional angiography. Finally, CEA was performed in 2 of 3 cases with severe carotid stonosis in the TIA group, while such cases in the stroke group were only observed. The above results meant that the occurrence of extracranial carotid stenosis was 6 out of 6,589 elderly inhabitants (over 60 years old), although the possible detection rate of candidates for CEA was 2 out of 20,000 population per year. (author).

  6. Thoracic CT

    Science.gov (United States)

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

  7. Screenings of lung cancer with low dose spiral CT: results of a three year pilot study and design of the randomised controlled trial Italung-CT; Screening della neoplasia polmonare con TC spirale a bassa dose: risultati di uno studio pilota triennale e disegno dello studio clinico randomizzato Italung-CT

    Energy Technology Data Exchange (ETDEWEB)

    Picozzi, Giulia [Firenze Univ., Firenze (Italy). Radiodiagnostica I-Dipartimento di Fisiopatologia Clinica; Paci, Enrico [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). Unita' di Epidemiologia Clinica e Descrittiva Centro per lo Studio e la Prevenzione Oncologica; Lopes Pegna, Andrea [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). U.O. Pneumologia] [and others

    2005-02-01

    Purpose: To report the results of a three-year observational pilot study of lung cancer screening with low dose computed tomography (CT) and to present the study design of a randomised clinical trial named as Italung CT. Materials and methods: Sixty (47 males and 13 females, mean age 64{+-}4.5 years) heavy smokers (at least 20 packs-year) underwent three low-dose spiral CT screening tests one year apart on a single slice or multislice CT scanner. Indeterminate nodules were managed according to the recommendations of the Early Lung Cancer Action Project. Results: Indeterminate nodules were observed in 33 (55%) of the subjects (60% at the baseline screening test, 24% at the first annual test and 16% at the second annual test). The size of the largest indeterminate nodule was <5mm in diameter in 20 subjects. 10 of whom showed the nodule at the baseline test. Forty-five subjects (75%) completed the first annual test and 42 (70%) the second annual test. One (1.6%) prevalent lung cancer (adenosquamous carcinoma) and one (2.2%) incident lung cancer (small cell cancer at the first annual examination) were observed, as well as pulmonary localisation of Hodgkin's lymphoma (at the second annual test). In addition, one subject underwent lung surgery for a chondromatous hamartoma. Conclusions: The results of the pilot study are substantially in line with those of other observational studies of greater sample size. This justifies optimism about the reliability of the results in the screened arm of the Italung Ct trial which hast just began. [Italian] Scopo: Riportare i risultati di uno studio pilota osservazionale di screening della neoplasia polmonare con TC a bassa dose della durata di tre anni e presentare il disegno dello studio clinico randomizzato Italung-CT. Materiale e metodi: Sessanta (47 uomini e 13 donne, eta' media 64{+-}4,5 anni) forti fumatori (almeno 20 pacchetti/anno) sono stati sottoposti ad un esame basale e a due controlli annuali con TC single o

  8. {sup 18}F-FDG PET/CT in the early prediction of pathological response in aggressive subtypes of breast cancer: review of the literature and recommendations for use in clinical trials

    Energy Technology Data Exchange (ETDEWEB)

    Groheux, David [Saint-Louis Hospital, Department of Nuclear Medicine, Paris Cedex 10 (France); INSERM/CNRS UMR944/7212, University Paris-Diderot, PRES Paris Cite, Paris (France); Mankoff, David [University of Pennsylvania Perelman School of Medicine, Department of Radiology, Philadelphia (United States); Espie, Marc [INSERM/CNRS UMR944/7212, University Paris-Diderot, PRES Paris Cite, Paris (France); Saint-Louis Hospital, Department of Medical Oncology, Breast Diseases Centre, Paris (France); Hindie, Elif [University of Bordeaux, Department of Nuclear Medicine, Haut-Leveque Hospital, Bordeaux (France)

    2016-05-15

    Early assessment of response to neoadjuvant chemotherapy (NAC) might be helpful in avoiding the toxicity of ineffective chemotherapy and allowing refinement of treatment. We conducted a review of the literature regarding the applicability of {sup 18}F-FDG PET/CT to the prediction of an early pathological response in different subgroups of breast cancer. Clinical research in this field has intensified in the last few years. Early studies by various groups have shown the potential of {sup 18}F-FDG PET/CT in the early assessment of response to NAC. However, interim PET/CT in breast cancer has not yet gained wide acceptance compared to its use in other settings such as lymphomas. This is in part due to a lack of consensus that early evaluation of response can be used to direct change in therapy in the neoadjuvant breast cancer setting, and only limited data showing that response-adaptive therapy leads to improved outcomes. However, one major element that has hampered the use of {sup 18}F-FDG PET/CT in directing neoadjuvant therapy is its evaluation in populations with mixed subtypes of breast cancer. However, major improvements have occurred in recent years. Pilot studies have highlighted the need for considering breast cancer subtype and the type of treatment, and have offered criteria for the use of PET/CT for the early prediction of response in specific settings. {sup 18}F-FDG PET/CT has considerable potential for the early prediction of pathological complete response to NAC in aggressive subtypes such as triple-negative or HER2-positive breast cancers. The results of a multicentre trial that used early metabolic response on {sup 18}F-FDG PET/CT as a means to select poor responders to adapt neoadjuvant treatment have recently been published. Other trials are ongoing or being planned. (orig.)

  9. Can surgeons assess CT suitability for endovascular repair (EVAR) in ruptured abdominal aortic aneurysm? Implications for a ruptured EVAR trial.

    Science.gov (United States)

    Rayt, Harjeet; Lambert, Kelly; Bown, Matthew; Fishwick, Guy; Morgan, Robert; McCarthy, Mark; London, Nick; Sayers, Robert

    2008-01-01

    The purpose of this study was to determine whether surgeons without formal radiological training are able to assess suitability of patients with ruptured abdominal aortic aneurysms (AAA) for EVAR. The CT scans of 20 patients with AAA were reviewed under timed conditions by six vascular surgeons. Twenty minutes was allocated per scan. They were asked to determine if each aneurysm would be treatable by EVAR in the emergency setting and, if so, to measure for device selection. The results were then compared with those of a vascular radiologist. Six surgeons agreed on the suitability of endovascular repair in 45% of cases (95% CI, 23.1-68.5%; 9/20 scans; kappa = 0.41 [p = 0.01]) and concurred with the radiologist in eight of these. Individually, agreement ranged from 13 to 16 of the 20 scans, 65-80% between surgeons. The kappa value for agreement between all the surgeons and the radiologist was 0.47 (p = 0.01, moderate agreement). For the individual surgeons, this ranged from 0.3 to 0.6 (p = 0.01). In conclusion, while overall agreement was moderate between the surgeons and the radiologist, it is clear that if surgeons are to assess patients for ruptured EVAR in the future, focused training of surgical trainees is required.

  10. Semantic Normalization and Query Abstraction Based on SNOMED-CT and HL7: Supporting Multicentric Clinical Trials.

    Science.gov (United States)

    Paraiso-Medina, Sergio; Perez-Rey, David; Bucur, Anca; Claerhout, Brecht; Alonso-Calvo, Raul

    2015-05-01

    Advances in the use of omic data and other biomarkers are increasing the number of variables in clinical research. Additional data have stratified the population of patients and require that current studies be performed among multiple institutions. Semantic interoperability and standardized data representation are a crucial task in the management of modern clinical trials. In the past few years, different efforts have focused on integrating biomedical information. Due to the complexity of this domain and the specific requirements of clinical research, the majority of data integration tasks are still performed manually. This paper presents a semantic normalization process and a query abstraction mechanism to facilitate data integration and retrieval. A process based on well-established standards from the biomedical domain and the latest semantic web technologies has been developed. Methods proposed in this paper have been tested within the EURECA EU research project, where clinical scenarios require the extraction of semantic knowledge from biomedical vocabularies. The aim of this paper is to provide a novel method to abstract from the data model and query syntax. The proposed approach has been compared with other initiatives in the field by storing the same dataset with each of those solutions. Results show an extended functionality and query capabilities at the cost of slightly worse performance in query execution. Implementations in real settings have shown that following this approach, usable interfaces can be developed to exploit clinical trial data outcomes.

  11. MicroPET/CT Colonoscopy in long-lived Min mouse using NM404

    Science.gov (United States)

    Christensen, Matthew B.; Halberg, Richard B.; Schutten, Melissa M.; Weichert, Jamey P.

    2009-02-01

    Colon cancer is a leading cause of death in the US, even though many cases are preventable if tumors are detected early. One technique to promote screening is Computed Tomography Colonography (CTC). NM404 is a second generation phospholipid ether analogue which has demonstrated selective uptake and prolonged retention in 43/43 types of malignant tumors but not inflammatory sites or premalignant lesions. The purpose of this experiment was to evaluate (SWR x B6 )F1.Min mice as a preclinical model to test MicroPET/CT dual modality virtual colonoscopy. Each animal was given an IV injection of 124I-NM404 (100 uCi) 24, 48 and 96 hours prior to scanning on a dedicated microPET/CT system. Forty million counts were histogrammed in 3D and reconstructed using an OSEM 2D algorithm. Immediately after PET acquisition, a 93 m volumetric CT was acquired at 80 kVp, 800 uA and 350 ms exposures. Following CT, the mouse was sacrificed. The entire intestinal tract was excised, washed, insufflated, and scanned ex vivo A total of eight tissue samples from the small intestine were harvested: 5 were benign adenomas, 2 were malignant adenocarcinomas, and 1 was a Peyer's patch (lymph tissue) . The sites of these samples were positioned on CT and PET images based on morphological cues and the distance from the anus. Only 1/8 samples showed tracer uptake. several hot spots in the microPET image were not chosen for histology. (SWR x B6)F1.Min mice develop benign and malignant tumors, making this animal model a strong candidate for future dual modality microPET/CT virtual colonography studies.

  12. Observer variability in the assessment of CT coronary angiography and coronary artery calcium score: substudy of the Scottish COmputed Tomography of the HEART (SCOT-HEART) trial.

    Science.gov (United States)

    Williams, Michelle C; Golay, Saroj K; Hunter, Amanda; Weir-McCall, Jonathan R; Mlynska, Lucja; Dweck, Marc R; Uren, Neal G; Reid, John H; Lewis, Steff C; Berry, Colin; van Beek, Edwin J R; Roditi, Giles; Newby, David E; Mirsadraee, Saeed

    2015-01-01

    Observer variability can influence the assessment of CT coronary angiography (CTCA) and the subsequent diagnosis of angina pectoris due to coronary heart disease. We assessed 210 CTCAs from the Scottish COmputed Tomography of the HEART (SCOT-HEART) trial for intraobserver and interobserver variability. Calcium score, coronary angiography and image quality were evaluated. Coronary artery disease was defined as none (70%) luminal stenosis and classified as no (70%) coronary artery disease. Post-CTCA diagnosis of angina pectoris due to coronary heart disease was classified as yes, probable, unlikely or no. Patients had a mean body mass index of 29 (28, 30) kg/m(2), heart rate of 58 (57, 60)/min and 62% were men. Intraobserver and interobserver agreements for the presence or absence of coronary artery disease were excellent (95% agreement, κ 0.884 (0.817 to 0.951) and good (91%, 0.791 (0.703 to 0.879)). Intraobserver and interobserver agreement for the presence or absence of angina pectoris due to coronary heart disease were excellent (93%, 0.842 (0.918 to 0.755) and good (86%, 0.701 (0.799 to 0.603)), respectively. Observer variability of calcium score was excellent for calcium scores below 1000. More segments were categorised as uninterpretable with 64-multidetector compared to 320-multidetector CTCA (10.1% vs 2.6%, pcoronary heart disease. NCT01149590.

  13. CT coronary angiography in patients with suspected angina due to coronary heart disease (SCOT-HEART): an open-label, parallel-group, multicentre trial.

    Science.gov (United States)

    2015-06-13

    The benefit of CT coronary angiography (CTCA) in patients presenting with stable chest pain has not been systematically studied. We aimed to assess the effect of CTCA on the diagnosis, management, and outcome of patients referred to the cardiology clinic with suspected angina due to coronary heart disease. In this prospective open-label, parallel-group, multicentre trial, we recruited patients aged 18-75 years referred for the assessment of suspected angina due to coronary heart disease from 12 cardiology chest pain clinics across Scotland. We randomly assigned (1:1) participants to standard care plus CTCA or standard care alone. Randomisation was done with a web-based service to ensure allocation concealment. The primary endpoint was certainty of the diagnosis of angina secondary to coronary heart disease at 6 weeks. All analyses were intention to treat, and patients were analysed in the group they were allocated to, irrespective of compliance with scanning. This study is registered with ClinicalTrials.gov, number NCT01149590. Between Nov 18, 2010, and Sept 24, 2014, we randomly assigned 4146 (42%) of 9849 patients who had been referred for assessment of suspected angina due to coronary heart disease. 47% of participants had a baseline clinic diagnosis of coronary heart disease and 36% had angina due to coronary heart disease. At 6 weeks, CTCA reclassified the diagnosis of coronary heart disease in 558 (27%) patients and the diagnosis of angina due to coronary heart disease in 481 (23%) patients (standard care 22 [1%] and 23 [1%]; pcoronary heart disease increased (1·09, 1·02-1·17; p=0·0172), the certainty increased (1·79, 1·62-1·96; pcoronary heart disease. This changed planned investigations (15% vs 1%; pcoronary heart disease, CTCA clarifies the diagnosis, enables targeting of interventions, and might reduce the future risk of myocardial infarction. The Chief Scientist Office of the Scottish Government Health and Social Care Directorates funded the trial

  14. Differences in Patient Outcomes of Prevalence, Interval, and Screen-Detected Lung Cancers in the CT Arm of the National Lung Screening Trial.

    Science.gov (United States)

    Schabath, Matthew B; Massion, Pierre P; Thompson, Zachary J; Eschrich, Steven A; Balagurunathan, Yoganand; Goldof, Dmitry; Aberle, Denise R; Gillies, Robert J

    2016-01-01

    Lung cancer screening identifies cancers with heterogeneous behaviors. Some lung cancers will be identified among patients who had prior negative CT screens and upon follow-up scans develop a de novo nodule that was determined to be cancerous. Other lung cancers will be identified among patients who had one or more prior stable positive scans that were not determined to be lung cancer (indeterminate pulmonary nodules), but in follow-up scans was diagnosed with an incidence lung cancer. Using data from the CT arm of the National Lung Screening Trial, this analysis investigated differences in patient characteristics and survival endpoints between prevalence-, interval-, and screen-detected lung cancers, characterized based on sequence of screening results. Lung cancers immediately following a positive baseline (T0), and prior to the T1 screen, formed the prevalence cohort. Interval cancers were diagnosed following a negative screen at any time point prior to the next screening round. Two cohorts of screen-detected lung cancers (SDLC) were identified that had a baseline positive screen that was that was not determined to be lung cancer (i.e., an indeterminate pulmonary nodule), but in follow-up scans was diagnosed with an incidence lung cancer 12 (SDLC1) or 24 (SDLC2) months later. Two other incidence cohorts had screen-detected lung cancers that had baseline negative screen and upon follow-up scans developed a de novo nodule determined to be cancerous at 12 (SDLC3) or 24 (SDLC4) months later. Differences in patient characteristics, progression-free survival (PFS), and overall survival (OS) were assessed. The lung cancer-specific death rate was higher for SDLC3/SDLC4 compared to SDLC1/SDLC2 lung cancers (136.6/1,000 person-years vs. 71.3/1,000 person-years, P < 0.001). Moreover, PFS and OS were significantly lower for SDLC3/SDLC4 compared to SDLC1/SDLC2 (P < 0.004; P < 0.002, respectively). The findings were consistent when stratified by stage and histology

  15. Effect of intravenous Buscopan on colonic distention during computed tomography colonography

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, C. [Univ. of British Columbia, Vancouver, British Columbia (Canada); Stevenson, G. [Dept. of Radiology, McMaster Univ., Hamilton, Ontario (Canada); Vancouver Island Health Authority, Victoria, British Columbia (Canada)], E-mail: gilse@shaw.ca; Eddy, R. [Royal Jublilee Hospital, Victoria, British Columbia (Canada); Mathieson, J. [Vancouver Island Health Authority, Victoria, British Columbia (Canada)

    2008-10-15

    This study was designed to assess whether spasmolytic drugs are helpful in computed tomography colonography (CTC), as there is conflict in the literature. We assessed retrospectively in a blinded fashion colonic distention in 149 individuals, one-half of whom had intravenous (IV) Buscopan during CTC. Colonic segments (n = 1788) were analyzed by 2 observers, and allocated to one of 4 grades of the distention. We also recorded the presence and severity of diverticular disease. Buscopan increased the likelihood of optimal distention by an OR of 5 when considering individual colonic segments from ascending colon to sigmoid, with little effect on rectum or cecum. Considering the colon as a whole, the OR of optimal distention occurring throughout the entire colon was 7.9 times greater with Buscopan than without. In the sigmoid colon, Buscopan had a significantly greater impact on obtaining optimal distention in those with diverticulosis than in those without. Buscopan increases the probability of obtaining optimal distention during CTC, especially in the sigmoid colon in diverticular disease. Buscopan is likely to improve polyp conspicuity and patient comfort, and to reduce both the examination time during and the interpretation time We recommend routine use of Buscopan during CTC. (author)

  16. Dark-lumen magnetic resonance colonography in patients with suspected sigmoid diverticulitis: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Ajaj, Waleed; Lauenstein, Thomas; Goehde, Susanne; Kuehle, Christiane; Herborn, Christoph U. [University Hospital, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Ruehm, Stefan G. [University of California, Department of Radiology, David Geffen School of Medicine, Los Angeles, CA (United States); Langhorst, Jost; Zoepf, Thomas; Gerken, Guido [University Hospital, Department of Gastroenterology and Hepatology, Essen (Germany); Goyen, Mathias [Medical Center Hamburg-Eppendorf, Hamburg (Germany)

    2005-11-01

    To assess dark-lumen magnetic resonance colonography (MRC) for the evaluation of patients with suspected sigmoid diverticulitis. Forty patients with suspected sigmoid diverticulitis underwent MRC within 72 h prior to conventional colonoscopy (CC). A three-dimensional T1-weighted volumetric interpolated breath-hold examination sequence was acquired after an aqueous enema and intravenous administration of gadolinium-based contrast agents. All MRC data were evaluated by two radiologists. Based on wall thickness and focal uptake of contrast material and pericolic reaction including mesenteric infiltration on T1-weighted sequence the sigmoid colon was assessed for the presence of diverticulitis. MRC classified 17 of the 40 patients as normal with regard to sigmoid diverticulitis. However, CC confirmed the presence of light inflammatory signs in four patients which were missed in MRC. MRC correctly identified wall thickness and contrast uptake of the sigmoid colon in the other 23 patients. In three of these patients false-positive findings were observed, and MRC classified the inflammation of the sigmoid colon as diverticulitis whereas CC and histopathology confirmed invasive carcinoma. MRC detected additionally relevant pathologies of the entire colon and could be performed in cases where CC was incomplete. MRC may be considered a promising alternative to CC for the detection of sigmoid diverticulitis. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Hiebinger, Cora

    2009-02-01

    Full Text Available Health political background: Colorectal cancer (CC is the second most common cancer and cause of cancer death for both men and women in Germany. Various methods for early detection of CC exist, including conventional coloscopy which is reimbursed within the scope of cancer screening, as well as computertomography-coloscopy (CTC which is currently not reimbursed. Scientific background: CTC is a mere diagnostic procedure which has a lower risk of perforation than conventional coloscopy. However, as it is an x-ray procedure, it exposes the patient to radiation. Conventional coloscopy is considered the gold standard due to its high sensitivity and specificity for locating adenomas. Furthermore, it offers the advantage that in addition to extended diagnostic measures therapeutic measures can be undertaken during the procedure. Research questions: This HTA-report aims to evaluate the effectiveness and efficiency of CTC in comparison to conventional coloscopy in the early detection and diagnosis of colorectal cancer and/or its precursors and which ethical and legal aspects have to be considered. Methods: The systematic literature search (27 international literature data bases yielded a total of 1,713 abstracts. After a two-step selection process 36 publications remained to be assessed. Results: The results regarding the effectivity of CTC in diagnosis and screening for colorectal cancer and/or its precursors are partly promising, however, they are very heterogeneous. Therefore, regarding its sensitivity and specificity, CTC cannot be considered an equivalent alternative to conventional coloscopy for diagnosis and screening. The heterogeneity of results is due to technical (device type, settings, patient dependent (preparation and operator dependent (training factors. No economic results for a comparison of the procedures for diagnosis exist. Regarding the cost-effectiveness of a CTC-screening, international model calculations are available. According to this calculation, the CTC-screening is cost-effective compared to the option ‘no screening’; however, conventional coloscopy-screening is generally more cost-effective.DiscussionIf modern CTC-devices are used with adequate technical settings, software, appropriate patient preparation and training of the operator, better results regarding sensitivity can be expected. Basically, the fact that no therapeutic measures (polypectomy can be taken during CTC compared to conventional coloscopy needs to be considered. Unanswered medical questions pertain to the interval of examinations for screening (considering the radiation exposure, the approach to small polyps and the significance of flat and depressed lesions. Regarding its cost-effectiveness, conventional coloscopy-screening results in greater health benefits and lower costs than CTC-screening in most model calculations. These results cannot be applied to Germany directly. An important ethical aspect is the consideration of patient preferences regarding the procedures. Legal aspects concern the stipulation and maintenance of quality standards. Conclusions: At this time, a clear endorsement of CTC as an alternative procedure for diagnosis and screening to the current gold standard conventional coloscopy cannot be given. On the basis of the available literature this holds true for both the medical as well as the economic assessment. However, despite the numerous studies and analyses on this topic, this assessment is afflicted with uncertainties. Due to the rapid development of CTC, short term revisions of these research questions are needed.

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

    Directory of Open Access Journals (Sweden)

    Mohammed Farghally Amin

    2015-09-01

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

  19. CT Colonography in the Detection of Colorectal Cancer in Ireland; Economical Considerations and the Potential for Centralisation of Service Provision

    LENUS (Irish Health Repository)

    Torreggiani, WC

    2016-10-01

    Colorectal cancer (CRC) is the second most common cancer in Ireland (excluding non melanomatous skin cancer)1.There were roughly 950 women and 1,330 men diagnosed with colorectal cancer annually in Ireland during 2007-20091. By 2020, with our aging population it is estimated that there will be an increase in colorectal cancer of 79 per cent in men and 56 per cent in women1. Colorectal cancer screening by faecal occult blood testing has been shown to reduce CRC mortality. In Europe, colonoscopy is mainly used to investigate faecal occult blood test positive or symptomatic patients, or as a preventive strategy in those with increased CRC risk2

  20. Comparative assessment of image quality for coronary CT angiography with iobitridol and two contrast agents with higher iodine concentrations: iopromide and iomeprol. A multicentre randomized double-blind trial

    Energy Technology Data Exchange (ETDEWEB)

    Achenbach, Stephan [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Department of Cardiology, Erlangen (Germany); Paul, Jean-Francois [Centre Chirurgical Marie Lannelongue, Department of Radiology, Le Plessis Robinson (France); Laurent, Francois [University of Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux (France); CHU de Bordeaux, Service d' Imagerie Thoracique et Cardiovasculaire, Pessac (France); Becker, Hans-Christoph [University Hospital Grosshadern, Department of Clinical Radiology, Munich (Germany); Rengo, Marco [Sapienza - University of Rome, ICOT Hospital, Department of Radiological Sciences, Oncology and Pathology, Latina (Italy); Caudron, Jerome [University Hospital of Rouen, Department of Radiology, Rouen (France); Leschka, Sebastian [Saint Gallen Hospital, Department of Radiology, Saint Gallen (Switzerland); Vignaux, Olivier [Cochin Hospital, Department of Radiology, Paris (France); Knobloch, Gesine [La Charite, Department of Radiology, Berlin (Germany); Benea, Giorgio [Ospedale del Delta, Ferrara (Italy); Schlosser, Thomas [Elisabeth-Krankenhaus Hospital, Essen (Germany); Andreu, Jordi [Hospital Vall d' Hebron, Barcelona (Spain); Cabeza, Beatriz [Hospital Clinico San Carlos, Madrid (Spain); Jacquier, Alexis [La Timone Adult Hospital, Department of Radiology, Marseille (France); Souto, Miguel [Complejo Hospitalario Universitario, Santiago de Compostela (Spain); Revel, Didier [Louis Pradel Hospital, Department of Radiology, Lyon (France); Qanadli, Salah Dine [University of Lausanne, Department of Radiology, Lausanne (Switzerland); Cademartiri, Filippo [Giovanni XXIII Hospital, Department of Radiology, Monastier di Treviso (Italy); Collaboration: X-ACT Study Group

    2017-02-15

    To demonstrate non-inferiority of iobitridol 350 for coronary CT angiography (CTA) compared to higher iodine content contrast media regarding rate of patients evaluable for the presence of coronary artery stenoses. In this multicentre trial, 452 patients were randomized to receive iobitridol 350, iopromide 370 or iomeprol 400 and underwent coronary CTA using CT systems with 64-detector rows or more. Two core lab readers assessed 18 coronary segments per patient regarding image quality (score 0 = non diagnostic to 4 = excellent quality), vascular attenuation, signal and contrast to noise ratio (SNR, CNR). Patients were considered evaluable if no segment had a score of 0. Per-patient, the rate of fully evaluable CT scans was 92.1, 95.4 and 94.6 % for iobitridol, iopromide and iomeprol, respectively. Non-inferiority of iobitridol over the best comparator was demonstrated with a 95 % CI of the difference of [-8.8 to 2.1], with a pre-specified non-inferiority margin of -10 %. Although average attenuation increased with higher iodine concentrations, average SNR and CNR did not differ between groups. With current CT technology, iobitridol 350 mg iodine/ml is not inferior to contrast media with higher iodine concentrations in terms of image quality for coronary stenosis assessment. (orig.)

  1. Reduced image noise at low-dose multidetector CT of the abdomen with prior image constrained compressed sensing algorithm.

    Science.gov (United States)

    Lubner, Meghan G; Pickhardt, Perry J; Tang, Jie; Chen, Guang-Hong

    2011-07-01

    To assess the effect of prior image constrained compressed sensing (PICCS) on noise reduction and image quality at low-dose computed tomography (CT). This HIPAA-compliant institutional review board-approved retrospective study was performed by using DICOM CT colonography data sets obtained in 20 adult patients. Informed consent was waived. Low-dose CT colonography was performed with 64-detector CT by using the standard protocol with mean effective dose per series of 3.06 mSv (range, 1.4-7.7 mSv). PICCS was applied to standard filtered back-projection (FBP) series. For FBP and PICCS series, mean and standard deviation (SD) of attenuation were obtained with 100-mm(2) circular region of interest (ROI) at six sites (240 soft-tissue, colonic gas, and subcutaneous fat measurements). Two abdominal radiologists reviewed two- and three-dimensional CT colonography displays and graded image quality with a five-point scale. Phantom studies were performed to compare spatial resolution and image quality between FBP and PICCS. Mean image noise and image quality scores were calculated and compared for clinical and phantom data sets. Bland-Altman, generalized estimating equation regression model, and Student t tests were used to obtain limits of agreement and to compare noise ratios and subjective image quality. Mean SD of attenuation (image noise) for ROIs was 38.0 for FBP and 12.2 for PICCS, corresponding to a noise-reduction factor of 3.1 (P < .001). Average noise reduction was 3.3 for soft tissue, 2.8 for air, and 3.0 for fat attenuation. Attenuation did not substantially change between FBP and PICCS images. Average two-dimensional image quality was 2.45 for FBP and 3.4 for PICCS (P < .001). Average three-dimensional image quality at three sites in the colon was 3.5 for FBP and 3.7 for PICCS (P = .34). Phantom data sets revealed no loss of spatial resolution in a line phantom and reduced noise in a liver tumor phantom when PICCS was compared with FBP. Application of PICCS to

  2. Magnetic resonance colonography without bowel cleansing using oral and rectal stool softeners (fecal cracking) - a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Ajaj, Waleed; Lauenstein, Thomas C.; Kuehle, Christiane; Herborn, Christoph U.; Goehde, Susanne C. [University Hospital of Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Schneemann, Hubert [University Hospital of Essen, Institute of Pharmacy and Pharmaceutical Sciences, Essen (Germany); Ruehm, Stefan G. [David Geffen School of Medicine at UCLA, Department of Radiology, Los Angeles, CA (United States); Goyen, Mathias [University Hospital of Hamburg-Eppendorf, Medical Center, Hamburg (Germany)

    2005-10-01

    The aim of our study was to assess the effect of oral and rectal stool softeners on dark-lumen magnetic resonance (MR) colonography without bowel cleansing. Ten volunteers underwent MR colonography without colonic cleansing. A baseline examination was performed without oral or rectal administration of stool softeners. In a second set, volunteers ingested 60 ml of lactulose 24 h prior to MR examination. In a third examination, water as a rectal enema was replaced by a solution of 0.5%-docusate sodium (DS). A fourth MR examination was performed, in conjunction with both oral administration of lactulose and rectal application of DS. A T1-weighted data set was acquired at scanning times of 0, 5 and 10 min after colonic filling. A fourth data set was acquired 75 s after i.v. injection of contrast agent. Signal intensity of stool was calculated for all colonic segments. Without oral ingestion of lactulose or rectal enema with DS stool signal intensity was high and did not decrease over time. However, lactulose and DS caused a decrease in stool signal intensity. Both substances together led to a decreasing signal intensity of feces. Combination of lactulose and DS provided the lowest signal intensity of stool. Thus, feces could hardly be distinguished from dark rectal enema allowing for the assessment of the colonic wall. (orig.)

  3. Head CT scan

    Science.gov (United States)

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

  4. Variation in quantitative CT air trapping in heavy smokers on repeat CT examinations

    NARCIS (Netherlands)

    Mets, O.M.; Isgum, I.; Mol, C.P.; Gietema, H.A.; Zanen, P.; Prokop, M.; Jong, Pim A. de

    2012-01-01

    OBJECTIVES: To determine the variation in quantitative computed tomography (CT) measures of air trapping in low-dose chest CTs of heavy smokers. METHODS: We analysed 45 subjects from a lung cancer screening trial, examined by CT twice within 3‘months. Inspiratory and expiratory low-dose CT was

  5. Variation in quantitative CT air trapping in heavy smokers on repeat CT examinations

    NARCIS (Netherlands)

    Mets, O.M.; Isgum, I.; Mol, C.P.; Gietema, H.A.; Zanen, P.; Prokop, M.; Jong, Pim A. de

    2012-01-01

    OBJECTIVES: To determine the variation in quantitative computed tomography (CT) measures of air trapping in low-dose chest CTs of heavy smokers. METHODS: We analysed 45 subjects from a lung cancer screening trial, examined by CT twice within 3‘months. Inspiratory and expiratory low-dose CT was obtai

  6. Trials

    Directory of Open Access Journals (Sweden)

    Michele Fornaro

    2010-01-01

    Full Text Available Mental Retardation (MR is a developmental disability characterized by impairments in adaptive daily life skills and difficulties in social and interpersonal functioning. Since multiple causes may contribute to MR, associated clinical pictures may vary accordingly. Nevertheless, when psychiatric disorders as Treatment Resistant Depression (TRD and/or alcohol abuse co-exist, their proper detection and management is often troublesome, essentially due to a limited vocabulary MR people could use to describe their symptoms, feelings and concerns, and the lack of reliable screening tools. Furthermore, MR people are among the most medicated subjects, with (over prescription of antidepressants and/or typical antipsychotics being the rule rather than exception. Thus, treatment resistance or even worsening of depression, constitute frequent occurrences. This report describes the case of a person with MR who failed to respond to repetitive trials of antidepressant monotherapies, finally recovering using aripiprazole to fluvoxamine augmentation upon consideration of a putative bipolar diathesis for “agitated” TRD. Although further controlled investigations are needed to assess a putative bipolar diathesis in some cases of MR associated to TRD, prudence is advised in the long-term prescription of antidepressant monotherapies in such conditions.

  7. Magnetic resonance colonography for fibrosis assessment in rats with chronic colitis.

    Directory of Open Access Journals (Sweden)

    Chloé Melchior

    Full Text Available BACKGROUND: Magnetic resonance colonography (MRC has been developed to assess inflammatory bowel diseases. We aimed to assess the feasibility of MRC in rats with TNBS-induced chronic colitis and to confront imaging results with fibrosis and stenosing features of the model. MATERIALS AND METHODS: Chronic colitis was induced in 12 rats by weekly intra-rectal injection of increasing doses of TNBS for 6 weeks, while 8 control rats received the vehicle. At week 7, MRC was performed. Fibrosis scores were assessed and fibrosis mediators measured. RESULTS: Chronic colitis was associated with significant body weight loss (p<0.0001 and higher colon weight/length compared to controls (p = 0.0004. Fibrosis mediators and histological scores were significantly higher in rats with TNBS than in controls: α-SMA expression (0.9 versus 0.61, p = 0.0311 and fibrosis score (p = 0.0308. Colon wall thickness was higher in rats with TNBS than in controls: maximal thickness (2.38 versus 0.74 mm, p<0.0001 and minimal thickness (1.33 versus 0.48 mm, p<0.0001. Wall signal intensity on T2w images was higher in rats with TNBS than in controls (9040 versus 6192, p = 0.0101 and correlated with fibrosis score (r = 0.5214; p = 0.04. Luminal narrowing was higher in rats with TNBS (50.08 versus 10.33%, p<0.0001 and correlated with α-SMA expression (r = 0.5618; p = 0.01. Stenosis was observed in 7/9 rats with TNBS and in no controls (p = 0.0053. CONCLUSIONS: MRC is feasible and easily distinguishes rats with colitis from controls. MRC signs correlated with fibrosis parameters. MRC evaluation may be part of a new anti-fibrosis drug assessment in experimental models of chronic colitis.

  8. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M. A.; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem; Groen, Harry J. M.; de Koning, Harry J.; Oudkerk, Matthijs

    2016-01-01

    Background US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and thei

  9. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M. A.; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem; Groen, Harry J. M.; de Koning, Harry J.; Oudkerk, Matthijs

    2016-01-01

    BACKGROUND: US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and the

  10. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M A; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem P Th M; Groen, Harry J M; de Koning, Harry J.; Oudkerk, Matthijs

    BACKGROUND: US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and

  11. FAZA PET/CT hypoxia imaging in patients with squamous cell carcinoma of the head and neck treated with radiotherapy: Results from the DAHANCA 24 trial

    DEFF Research Database (Denmark)

    Mortensen, Lise Saksø; Johansen, Jørgen; Kallehauge, Jesper Folsted

    2012-01-01

    Hypoxia is a cause of resistance to radiotherapy, especially in patients with head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to evaluate (18)F-fluoroazomycin arabinoside (FAZA) positron emission tomography (PET)/computed tomography (CT) hypoxia imaging as a prognostic...

  12. High rates of clinically relevant incidental findings by total-body CT scanning in trauma patients; results of the REACT-2 trial

    Energy Technology Data Exchange (ETDEWEB)

    Treskes, K.; Bos, S.A.; Sierink, J.C.; Luitse, J.S.K.; Goslings, J.C. [Academic Medical Center, Trauma Unit, Department of Surgery, Amsterdam (Netherlands); Beenen, L.F.M. [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Edwards, M.J.R. [Radboud University Medical Center, Department of Trauma and emergency surgery, Nijmegen (Netherlands); Beuker, B.J.A. [University Medical Center Groningen, Trauma Unit, Department of Surgery, Groningen (Netherlands); Muradin, G.S.R. [University Medical Center Rotterdam, Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Hohmann, J. [University of Basel Hospital, Department of Radiology and Nuclear Medicine, Basel (Switzerland); Hollmann, M.W. [Academic Medical Center, Department of Anaesthesiology, Amsterdam (Netherlands); Dijkgraaf, M.G.W. [Academic Medical Center, Clinical Research Unit, Amsterdam (Netherlands); Collaboration: REACT-2 study group

    2017-06-15

    To determine whether there is a difference in frequency and clinical relevance of incidental findings detected by total-body computed tomography scanning (TBCT) compared to those by the standard work-up (STWU) with selective computed tomography (CT) scanning. Trauma patients from five trauma centres were randomized between April 2011 and January 2014 to TBCT imaging or STWU consisting of conventional imaging with selective CT scanning. Incidental findings were divided into three categories: 1) major finding, may cause mortality; 2) moderate finding, may cause morbidity; and 3) minor finding, hardly relevant. Generalized estimating equations were applied to assess differences in incidental findings. In total, 1083 patients were enrolled, of which 541 patients (49.9 %) were randomized for TBCT and 542 patients (50.1 %) for STWU. Major findings were detected in 23 patients (4.3 %) in the TBCT group compared to 9 patients (1.7 %) in the STWU group (adjusted rate ratio 2.851; 95%CI 1.337-6.077; p < 0.007). Findings of moderate relevance were detected in 120 patients (22.2 %) in the TBCT group compared to 86 patients (15.9 %) in the STWU group (adjusted rate ratio 1.421; 95%CI 1.088-1.854; p < 0.010). Compared to selective CT scanning, more patients with clinically relevant incidental findings can be expected by TBCT scanning. (orig.)

  13. CT Enterography

    Science.gov (United States)

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

  14. Impact of {sup 11}C-choline PET/CT on clinical decision making in recurrent prostate cancer: results from a retrospective two-centre trial

    Energy Technology Data Exchange (ETDEWEB)

    Ceci, Francesco [University of Bologna, Service of Nuclear Medicine, Policlinico S. Orsola-Malpighi, Bologna (Italy); Universitaetsklinikum Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, Bologna (Italy); Herrmann, Ken; Bluemel, Christina; Droll, Sabine; Buck, Andreas K. [Universitaetsklinikum Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Castellucci, Paolo; Graziani, Tiziano; Fanti, Stefano [University of Bologna, Service of Nuclear Medicine, Policlinico S. Orsola-Malpighi, Bologna (Italy); Schiavina, Riccardo; Brunocilla, Eugenio [University of Bologna, Department of Urology, Policlinico S. Orsola-Malpighi, Bologna (Italy); Vollmer, Christian [Universitaetsklinikum Wuerzburg, Department of Urology, Wuerzburg (Germany); Mazzarotto, Renzo [University of Bologna, Service of Radiotherapy, Policlinico S. Orsola-Malpighi, Bologna (Italy)

    2014-12-15

    The aim of this retrospective two-centre study was to investigate the clinical impact of {sup 11}C-choline PET/CT on treatment management decisions in patients with recurrent prostate cancer (rPCa) after radical therapy. Enrolled in this retrospective study were 150 patients (95 from Bologna, 55 from Wuerzburg) with rPCa and biochemical relapse (PSA mean ± SD 4.3 ± 5.5 ng/mL, range 0.2-39.4 ng/mL) after radical therapy. The intended treatment before PET/CT was salvage radiotherapy of the prostatic bed in 95 patients and palliative androgen deprivation therapy (ADT) in 55 patients. The effective clinical impact of {sup 11}C-choline PET/CT was rated as major (change in therapeutic approach), minor (same treatment, but modified therapeutic strategy) or none. Multivariate binary logistic regression analysis included PSA level, PSA kinetics, ongoing ADT, Gleason score, TNM, age and time to relapse. Changes in therapy after {sup 11}C-choline PET/CT were implemented in 70 of the 150 patients (46.7 %). A major clinical impact was observed in 27 patients (18 %) and a minor clinical impact in 43 (28.7 %). {sup 11}C-choline PET/CT was positive in 109 patients (72.7 %) detecting local relapse (prostate bed and/or iliac lymph nodes and/or pararectal lymph nodes) in 64 patients (42.7 %). Distant relapse (paraaortic and/or retroperitoneal lymph nodes and/or bone lesions) was seen in 31 patients (20.7 %), and both local and distant relapse in 14 (9.3 %). A significant difference was observed in PSA level and PSA kinetics between PET-positive and PET-negative patients (p < 0.05). In multivariate analysis, PSA level, PSA doubling time and ongoing ADT were significant predictors of a positive scan (p < 0.05). In statistical analysis no significant differences were observed between the Bologna and Wuerzburg patients (p > 0.05). In both centres the same criteria to validate PET-positive findings were used: in 17.3 % of patients by histology and in 82.7 % of patients by correlative

  15. Computed Tomography (CT) -- Head

    Medline Plus

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

  16. Computed Tomography (CT) -- Head

    Medline Plus

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

  17. Image quality of low mA CT pulmonary angiography reconstructed with model based iterative reconstruction versus standard CT pulmonary angiography reconstructed with filtered back projection: an equivalency trial

    Energy Technology Data Exchange (ETDEWEB)

    Montet, Xavier; Hachulla, Anne-Lise; Neroladaki, Angeliki; Botsikas, Diomidis; Becker, Christoph D. [Geneva University Hospital, Division of Radiology, Geneva 4 (Switzerland); Lador, Frederic; Rochat, Thierry [Geneva University Hospital, Division of Pulmonary Medicine, Geneva 4 (Switzerland)

    2015-06-01

    To determine whether CT pulmonary angiography (CTPA) using low mA setting reconstructed with model-based iterative reconstruction (MBIR) is equivalent to routine CTPA reconstructed with filtered back projection (FBP). This prospective study was approved by the institutional review board and patients provided written informed consent. Eighty-two patients were examined with a low mA MBIR-CTPA (100 kV, 20 mA) and 82 patients with a standard FBP-CTPA (100 kV, 250 mA). Region of interests were drawn in nine pulmonary vessels; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. A five-point scale was used to subjectively evaluate the image quality of FBP-CTPA and low mA MBIR-CTPA. Compared to routine FBP-CTPA, low mA MBIR-CTPA showed no differences in the attenuation measured in nine pulmonary vessels, higher SNR (56 ± 19 vs 43 ± 20, p < 0.0001) and higher CNR (50 ± 17 vs 38 ± 18, p < 0.0001) despite a dose reduction of 93 % (p < 0.0001). The subjective image quality of low mA MBIR-CTPA was quoted as diagnostic in 98 % of the cases for patient with body mass index less than 30 kg/m{sup 2}. Low mA MBIR-CTPA is equivalent to routine FBP-CTPA and allows a significant dose reduction while improving SNR and CNR in the pulmonary vessels, as compared with routine FBP-CTPA. (orig.)

  18. Implementation of a guideline-based clinical pathway of care to improve health outcomes following whiplash injury (Whiplash ImPaCT: protocol of a randomised, controlled trial

    Directory of Open Access Journals (Sweden)

    Trudy Rebbeck

    2016-04-01

    Discussion: This research is significant as it will be the first study to address the heterogeneity of whiplash by implementing a clinical pathway of care that matches evidence-based interventions to projected risk of poor recovery. The results of this trial have the potential to change clinical practice for WAD, thereby maximising treatment effects, improving patient outcomes, reducing costs and maintaining the compulsory third party system.

  19. Coronary CT Angiography Versus Standard Emergency Department Evaluation for Acute Chest Pain and Diabetic Patients: Is There Benefit With Early Coronary CT Angiography? Results of the Randomized Comparative Effectiveness ROMICAT II Trial.

    Science.gov (United States)

    Truong, Quynh A; Schulman-Marcus, Joshua; Zakroysky, Pearl; Chou, Eric T; Nagurney, John T; Fleg, Jerome L; Schoenfeld, David A; Udelson, James E; Hoffmann, Udo; Woodard, Pamela K

    2016-03-22

    Cardiac computed tomography angiography (CCTA) reduces emergency department length of stay compared with standard evaluation in patients with low- and intermediate-risk acute chest pain. Whether diabetic patients have similar benefits is unknown. In this prespecified analysis of the Rule Out Myocardial Ischemia/Infarction by Computer Assisted Tomography (ROMICAT II) multicenter trial, we randomized 1000 patients (17% diabetic) with symptoms suggestive of acute coronary syndrome to CCTA or standard evaluation. The rate of acute coronary syndrome was 8% in both diabetic and nondiabetic patients (P=1.0). Length of stay was unaffected by the CCTA strategy for diabetic patients (23.9 versus 27.2 hours, P=0.86) but was reduced for nondiabetic patients compared with standard evaluation (8.4 versus 26.5 hours, Pemergency department discharge in both groups (each P≤0.0001, P interaction=0.27). No difference in hospital admissions was seen between the 2 strategies in diabetic and nondiabetic patients (P interaction=0.09). Both groups had more downstream testing and higher radiation doses with CCTA, but these were highest in diabetic patients (all P interaction≤0.04). Diabetic patients had fewer normal CCTAs than nondiabetic patients (32% versus 50%, P=0.003) and similar normalcy rates with standard evaluation (P=0.70). Notably, 66% of diabetic patients had no or mild stenosis by CCTA with short length of stay comparable to that of nondiabetic patients (P=0.34), whereas those with >50% stenosis had a high prevalence of acute coronary syndrome, invasive coronary angiography, and revascularization. Knowledge of coronary anatomy with CCTA is beneficial for diabetic patients and can discriminate between lower risk patients with no or little coronary artery disease who can be discharged immediately and higher risk patients with moderate to severe disease who warrant further workup. URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01084239. © 2016 The Authors

  20. Native acetabular version: 3D CT analysis 
of the psoas valley.

    Science.gov (United States)

    Osmani, Humza Tariq; Henckel, Johann; Cobb, Justin; Hart, Alister J

    2013-01-01

    Insufficient version has been demonstrated to be a significant factor in increasing metal-on-metal cup wear. Another implication is the impingement of the psoas tendon at the anatomical depression on the anterior acetabular rim, called the psoas valley. It is not known whether the psoas valley has any anatomical significance when measuring native version. The effect of this landmark on the measurement of acetabular version has not been assessed using 3D CT.
Sixty five high resolution CT scans of non-diseased hips (performed for colonography) were used to measure the anatomical version angles of the bony acetabular rim. Our new method, using the psoas valley, was compared to the reference method, which used the full 320° of the acetabular rim. The measurement of acetabular version was highly reproducible between the methods. Both methods measured the angle of version over a wide range: 5° to 35° for males and 10° to 40° for females. There were no statistically significant differences between genders (p = 0.3670). The Bland-Altman 1.96 SD lower and upper limits of agreement between the two methods were +4.6° and -4.3°, respectively. Intra-observer and inter-observer reliability were high for the new method. This adds to our understanding of native bony anatomy, and specifically provides a landmark that 3D CT has demonstrated to be potentially useful in assessing native version.

  1. CT urography

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-11-15

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

  2. Predictive Accuracy of the PanCan Lung Cancer Risk Prediction Model -External Validation based on CT from the Danish Lung Cancer Screening Trial

    DEFF Research Database (Denmark)

    Winkler Wille, Mathilde M.; van Riel, Sarah J.; Saghir, Zaigham

    2015-01-01

    ; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST. Conclusions: High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were......Objectives: Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. Methods: From...... used to evaluate risk discrimination. Results: AUCs of 0.826–0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer...

  3. Perfusion-CT guided intravenous thrombolysis in patients with unknown-onset stroke: a randomized, double-blind, placebo-controlled, pilot feasibility trial

    Energy Technology Data Exchange (ETDEWEB)

    Michel, Patrik [Center Hospitalier Universitaire Vaudois and University of Lausanne, Department of Neurology Service, Lausanne (Switzerland); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Neurology Service, Lausanne (Switzerland); Ntaios, George; Reichhart, Marc [Center Hospitalier Universitaire Vaudois and University of Lausanne, Department of Neurology Service, Lausanne (Switzerland); Schindler, Christian [Center Hospitalier Universitaire Vaudois and University of Lausanne, Pharmacy Department, Lausanne (Switzerland); Bogousslavsky, Julien [Genolier Swiss Medical Network, Glion (Switzerland); Maeder, Philip; Meuli, Reto [Center Hospitalier Universitaire Vaudois and University of Lausanne, Department of Radiology, Lausanne (Switzerland); Wintermark, Max [University of Virginia, Department of Radiology, Division of Neuroradiology, Charlottesville, VA (United States)

    2012-06-15

    Patients with unknown stroke onset are generally excluded from acute recanalisation treatments. We designed a pilot study to assess feasibility of a trial of perfusion computed tomography (PCT)-guided thrombolysis in patients with ischemic tissue at risk of infarction and unknown stroke onset. Patients with a supratentorial stroke of unknown onset in the middle cerebral artery territory and significant volume of at-risk tissue on PCT were randomized to intravenous thrombolysis with alteplase (0.9 mg/kg) or placebo. Feasibility endpoints were randomization and blinded treatment of patients within 2 h after hospital arrival, and the correct application (estimation) of the perfusion imaging criteria. At baseline, there was a trend towards older age [69.5 (57-78) vs. 49 (44-78) years] in the thrombolysis group (n = 6) compared to placebo (n = 6). Regarding feasibility, hospital arrival to treatment delay was above the allowed 2 h in three patients (25%). There were two protocol violations (17%) regarding PCT, both underestimating the predicted infarct in patients randomized in the placebo group. No symptomatic hemorrhage or death occurred during the first 7 days. Three of the four (75%) and one of the five (20%) patients were recanalized in the thrombolysis and placebo group respectively. The volume of non-infarcted at-risk tissue was 84 (44-206) cm{sup 3} in the treatment arm and 29 (8-105) cm{sup 3} in the placebo arm. This pilot study shows that a randomized PCT-guided thrombolysis trial in patients with stroke of unknown onset may be feasible if issues such as treatment delays and reliable identification of tissue at risk of infarction tissue are resolved. Safety and efficiency of such an approach need to be established. (orig.)

  4. Perfusion CT in acute stroke; Stellenwert der CT-Perfusion fuer die Therapie des Schlaganfalls

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, Bernd [Asklepios Klinik Altona (Germany). Radiologie und Neuroradiologie; Roether, Joachim [Asklepios Klinik Altona (Germany). Neurologische Abt.; Fiehler, Jens [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Neuroradiologische Diagnostik und Intervention; Thomalla, Goetz [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Neurologie, Kopf- und Neurozentrum

    2015-06-15

    Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

  5. Computed Tomography (CT) -- Sinuses

    Medline Plus

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

  6. Computed Tomography (CT) -- Head

    Medline Plus

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

  7. Abdominal and Pelvic CT

    Medline Plus

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

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

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

  9. Abdominal and Pelvic CT

    Medline Plus

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

  10. Abdominal and Pelvic CT

    Science.gov (United States)

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

  11. Renal safety in pediatric imaging: randomized, double-blind phase IV clinical trial of iobitridol 300 versus iodixanol 270 in multidetector CT

    Energy Technology Data Exchange (ETDEWEB)

    Zo' o, Martin; Dosseur, Patrick Le [CHU Charles Nicolle, Radiology Department, Rouen (France); Hoermann, Marcus; Balassy, Csilla [AKH, Radiology Department, Vienna (Austria); Brunelle, Francis [Necker Hospital, Radiopediatry Department, Paris (France); Azoulay, Robin [Robert Debre Hospital, Radiopediatry Department, Paris (France); Pariente, Daniele [Kremlin-Bicetre Hospital, Radiopediatry Department, Kremlin-Bicetre (France); Panuel, Michel [Nord Hospital, Medical Imaging Department, Marseille (France)

    2011-11-15

    It is debated whether iso-osmolar and low-osmolar contrast media are associated with different incidences of contrast medium-induced nephropathy (CIN) in patients with renal insufficiency. To compare the incidence of CIN in children undergoing contrast-enhanced multidetector computer tomography (MDCT) with intravenous injection of low-osmolar (iobitridol, Xenetix {sup registered} 300) or an iso-osmolar (iodixanol, Visipaque {sup registered} 270) iodinated contrast medium. One hundred forty-six children with normal renal function were included in this multicenter trial and underwent contrast-enhanced MDCT. The primary endpoint was the relative change in creatinine clearance from 48 h pre- to 72 h postcontrast medium administration using a noninferiority analysis in the intent-to-treat (ITT, n = 128) and per protocol (n = 68) populations. Secondary endpoints were incidence of CIN, global image quality, diagnostic efficacy and clinical safety. In the ITT population, the noninferiority of iobitridol over iodixanol was demonstrated. CIN incidence was 4.8% (three cases) with iobitridol and 10.6% (seven cases) with iodixanol (not significant). No statistically significant differences were observed for the secondary endpoints. Comparable satisfactory safety profiles were confirmed for both contrast media, with no significant difference in the incidence of CIN in children with normal renal function. (orig.)

  12. Predictive accuracy of the PanCan lung cancer risk prediction model - external validation based on CT from the Danish Lung Cancer Screening Trial

    Energy Technology Data Exchange (ETDEWEB)

    Winkler Wille, Mathilde M.; Dirksen, Asger [Gentofte Hospital, Department of Respiratory Medicine, Hellerup (Denmark); Riel, Sarah J. van; Jacobs, Colin; Scholten, Ernst T.; Ginneken, Bram van [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Saghir, Zaigham [Herlev Hospital, Department of Respiratory Medicine, Herlev (Denmark); Pedersen, Jesper Holst [Copenhagen University Hospital, Department of Thoracic Surgery, Rigshospitalet, Koebenhavn Oe (Denmark); Hohwue Thomsen, Laura [Hvidovre Hospital, Department of Respiratory Medicine, Hvidovre (Denmark); Skovgaard, Lene T. [University of Copenhagen, Department of Biostatistics, Koebenhavn Oe (Denmark)

    2015-10-15

    Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. From the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were used to evaluate risk discrimination. AUCs of 0.826-0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST. High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were significant predictors and could be included in the parsimonious model. Sex appears to be a less useful predictor. (orig.)

  13. Combined SPECT/CT and PET/CT for breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Paolo [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Larobina, Michele [Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Tommaso De Amicis, 95, Naples I-80145 (Italy); Di Lillo, Francesca [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Del Vecchio, Silvana [Università di Napoli Federico II, Dipartimento di Scienze Biomediche Avanzate, Via Pansini, 5, Naples I-80131 (Italy); Mettivier, Giovanni, E-mail: mettivier@na.infn.it [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy)

    2016-02-11

    In the field of nuclear medicine imaging, breast imaging for cancer diagnosis is still mainly based on 2D imaging techniques. Three-dimensional tomographic imaging with whole-body PET or SPECT scanners, when used for imaging the breast, has performance limits in terms of spatial resolution and sensitivity, which can be overcome only with a dedicated instrumentation. However, only few hybrid imaging systems for PET/CT or SPECT/CT dedicated to the breast have been developed in the last decade, providing complementary functional and anatomical information on normal breast tissue and lesions. These systems are still under development and clinical trials on just few patients have been reported; no commercial dedicated breast PET/CT or SPECT/CT is available. This paper reviews combined dedicated breast PET/CT and SPECT/CT scanners described in the recent literature, with focus on their technological aspects.

  14. Segmentation of Lung Structures in CT

    DEFF Research Database (Denmark)

    Lo, Pechin Chien Pau

    This thesis proposes and evaluates new algorithms for segmenting various lung structures in computed tomography (CT) images, namely the lungs, airway trees and vessel trees. The main objective of these algorithms is to facilitate a better platform for studying Chronic Obstructive Pulmonary Disease...... (COPD) using CT scans from the Danish Lung Cancer Screening Trial (DLCST) study. We propose a fully automated lung segmentation algorithm that is based on region growing and the assumption that the lungs are of lower intensities than surrounding structures in CT. Furthermore, we also propose a post...... processing step that detects and removes esophagus regions, wrongly added by the region growing process, to improve the reliability of the lung segmentation algorithm. The proposed algorithm has been successfully applied to more than 6000 low dose CT scans from the DLCST study. Among the CT scans applied...

  15. Segmentation of Lung Structures in CT

    DEFF Research Database (Denmark)

    Lo, Pechin Chien Pau

    This thesis proposes and evaluates new algorithms for segmenting various lung structures in computed tomography (CT) images, namely the lungs, airway trees and vessel trees. The main objective of these algorithms is to facilitate a better platform for studying Chronic Obstructive Pulmonary Disease...... (COPD) using CT scans from the Danish Lung Cancer Screening Trial (DLCST) study. We propose a fully automated lung segmentation algorithm that is based on region growing and the assumption that the lungs are of lower intensities than surrounding structures in CT. Furthermore, we also propose a post...... processing step that detects and removes esophagus regions, wrongly added by the region growing process, to improve the reliability of the lung segmentation algorithm. The proposed algorithm has been successfully applied to more than 6000 low dose CT scans from the DLCST study. Among the CT scans applied...

  16. INtimal hyPerplasia evAluated by oCT in de novo COROnary lesions treated by drug-eluting balloon and bare-metal stent (IN-PACT CORO: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Burzotta Francesco

    2012-05-01

    antiproliferative drugs loaded on the surface of angioplasty balloons. The INtimal hyPerplasia evAluated by oCT in de novo COROnary lesions treated by drug-eluting balloon and bare-metal stent (IN-PACT CORO trial was conceived to test the superiority of a strategy of bare-metal stent implantation with additional drug-eluting balloon use (either before or after stenting versus a strategy of bare-metal stent implantation alone for the reduction of neointimal hyperplasia. We also planned an ancillary study to assess the role of endothelial progenitors cells in the pathophysiology of neointimal hyperplasia. Trial registration Clinicaltrials.gov NCT01057563.

  17. Intravenous, contrast-enhanced MR colonography using air as endoluminal contrast agent: Impact on colorectal polyp detection.

    LENUS (Irish Health Repository)

    Keeling, Aoife N

    2012-02-01

    PURPOSE: To compare diagnostic accuracy and patient tolerance of MR colonography with intravenous contrast and luminal air (MRC) to conventional colonoscopy (CC). MATERIALS AND METHODS: IRB approval and written informed consent were obtained. Forty-six patients, both screening and symptomatic, underwent MRC followed by CC. The MRC technique employed 3D T1W spoiled gradient echo sequences performed after the administration of gadopenetate dimeglumine, with parallel imaging. The diagnostic accuracy and tolerance of patients for MRC was compared to CC. RESULTS: Twenty-four polyps were detected in eighteen patients with CC (5 polyps >\\/=10mm, 4 polyps 6-9mm, 15 polyps <\\/=5mm). MRC was 66.7% (12\\/18) sensitive and 96.4% (27\\/28) specific for polyp detection on a per-patient basis. When analyzed by polyp size, sensitivity and specificity of MRC was 100% (5\\/5) and 100% (19\\/19), respectively, for lesions greater than 10mm, 100% (4\\/4) and 100% (20\\/20) for lesions 6-9mm, and sensitivity of 20% (3\\/15) lesions less than 5mm. The sensitivity and specificity of MRC for detecting significant lesions (>6mm) was 100% (9\\/9) and 100% (15\\/15), respectively. Regarding tolerance of the exams, there were no significant differences between MRC and CC. Thirty-five percent (n=16) of patients preferred MRC as a future screening test compared to 33% (n=15) for CC. CONCLUSION: MRC using air as an intraluminal contrast agent is a feasible and well-tolerated technique for detecting colonic polyps >\\/=6mm in size. Further studies are warranted.

  18. Incidental extracolonic findings on bright lumen MR colonography in a population at increased risk for colorectal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Yusuf, Erlangga, E-mail: angga.yusuf@gmail.com [Department of Radiology, Academic Medical Center, Amsterdam, Postbus 22660, 1100 DD Amsterdam (Netherlands); Florie, Jasper; Nio, Chung Yung; Jensch, Sebastian; Nievelstein, Rutger A.J.; Baak, Lubbertus; Stoker, Jaap [Department of Radiology, Academic Medical Center, Amsterdam, Postbus 22660, 1100 DD Amsterdam (Netherlands)

    2011-04-15

    Purpose: Incidental extracolonic findings affect patient treatment and cost. Therefore, to consider magnetic resonance colonography (MRC) as a tool for colorectal cancer and polyps screening, more knowledge is needed on extracolonic findings. In this study, we sought to determine the prevalence and the spectrum of extracolonic findings in patients with an increased risk colorectal cancer that underwent bright lumen MRC. Materials and methods: MRC examinations were performed in 210 patients. A gadolinium solution was administered rectally for distension of the colon. Extracolonic findings were scored by two radiologists and classified by using C-RADS Reporting System. All findings (with advice regarding work-up) were reported to the patient's physician and followed up for 4.5 years on average. Results: Extracolonic findings were found in 125 (59.5%) patients. Ten (4.8%) had 'potentially important' findings (C-RADS category E4). Twenty-five patients (11.9%) had 'likely unimportant' findings (E3), 90 (42.8%) had 'clinically unimportant' findings (E2) and 85 (40.5%) had a normal exam (E1). In 14 (6.7%) patients additional work-up was performed for their incidentally discovered lesions. In three of them surgery was performed. After work-up, only in two (1.0%) patients a malignancy was found. Conclusion: The number of new relevant extracolonic findings is small and the required additional work-up is limited. This should be considered for implementation of 'bright lumen' MRC as a screening tool.

  19. Intravenous, contrast-enhanced MR colonography using air as endoluminal contrast agent: Impact on colorectal polyp detection.

    LENUS (Irish Health Repository)

    Keeling, Aoife N

    2010-12-03

    PURPOSE: To compare diagnostic accuracy and patient tolerance of MR colonography with intravenous contrast and luminal air (MRC) to conventional colonoscopy (CC). MATERIALS AND METHODS: IRB approval and written informed consent were obtained. Forty-six patients, both screening and symptomatic, underwent MRC followed by CC. The MRC technique employed 3D T1W spoiled gradient echo sequences performed after the administration of gadopenetate dimeglumine, with parallel imaging. The diagnostic accuracy and tolerance of patients for MRC was compared to CC. RESULTS: Twenty-four polyps were detected in eighteen patients with CC (5 polyps ≥10mm, 4 polyps 6-9mm, 15 polyps ≤5mm). MRC was 66.7% (12\\/18) sensitive and 96.4% (27\\/28) specific for polyp detection on a per-patient basis. When analyzed by polyp size, sensitivity and specificity of MRC was 100% (5\\/5) and 100% (19\\/19), respectively, for lesions greater than 10mm, 100% (4\\/4) and 100% (20\\/20) for lesions 6-9mm, and sensitivity of 20% (3\\/15) lesions less than 5mm. The sensitivity and specificity of MRC for detecting significant lesions (>6mm) was 100% (9\\/9) and 100% (15\\/15), respectively. Regarding tolerance of the exams, there were no significant differences between MRC and CC. Thirty-five percent (n=16) of patients preferred MRC as a future screening test compared to 33% (n=15) for CC. CONCLUSION: MRC using air as an intraluminal contrast agent is a feasible and well-tolerated technique for detecting colonic polyps ≥6mm in size. Further studies are warranted.

  20. Machine Learning in Computer-aided Diagnosis of the Thorax and Colon in CT: A Survey.

    Science.gov (United States)

    Suzuki, Kenji

    2013-04-01

    Computer-aided detection (CADe) and diagnosis (CAD) has been a rapidly growing, active area of research in medical imaging. Machine leaning (ML) plays an essential role in CAD, because objects such as lesions and organs may not be represented accurately by a simple equation; thus, medical pattern recognition essentially require "learning from examples." One of the most popular uses of ML is the classification of objects such as lesion candidates into certain classes (e.g., abnormal or normal, and lesions or non-lesions) based on input features (e.g., contrast and area) obtained from segmented lesion candidates. The task of ML is to determine "optimal" boundaries for separating classes in the multidimensional feature space which is formed by the input features. ML algorithms for classification include linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), multilayer perceptrons, and support vector machines (SVM). Recently, pixel/voxel-based ML (PML) emerged in medical image processing/analysis, which uses pixel/voxel values in images directly, instead of features calculated from segmented lesions, as input information; thus, feature calculation or segmentation is not required. In this paper, ML techniques used in CAD schemes for detection and diagnosis of lung nodules in thoracic CT and for detection of polyps in CT colonography (CTC) are surveyed and reviewed.

  1. National Lung Screening Trial Results: Fast Facts

    Science.gov (United States)

    On November 4, 2010, the NLST reported initial trial results, showing 20 percent fewer lung cancer deaths among trial participants screened with low-dose helical CT (also known as spiral CT) compared to those who got screened with chest X-rays.

  2. National Lung Screening Trial (NLST)

    Science.gov (United States)

    The National Lung Screening Trial (NLST), a research study sponsored by the National Cancer Institute that used low-dose helical CT scans or chest X-ray to screen men and women at risk for lung cancer.

  3. Optimization of nodule management in CT lung cancer screening

    NARCIS (Netherlands)

    Heuvelmans, Marjolein Anne

    2015-01-01

    Lung cancer is the leading cancer-related cause of death. Through computed tomography (CT) screening, cancer can be detected at the earliest stage, with a much greater probability of cure. After the positive outcome of the US National Lung Screening Trial (NLST), screening with low-dose CT in heavy

  4. Health economic aspects of evaluation with diffusion weighted MR and MR colonography compared to standard evaluation with colonoscopy and CT before rectal cancer surgery

    DEFF Research Database (Denmark)

    Achiam, Michael P; Kjellberg, Jakob; Rosenberg, Jacob

    2017-01-01

    BACKGROUND: Colorectal cancer is a frequent type of cancer, and with the risk of synchronous disease, the need for a complete staging leads to an extensive and costly preoperative diagnostic evaluation. Previously we described a total preoperative evaluation using magnetic resonance (MR...

  5. European randomized lung cancer screening trials: Post NLST

    DEFF Research Database (Denmark)

    Field, JK; Klaveren, R; Pedersen, JH;

    2013-01-01

    Overview of the European randomized lung cancer CT screening trials (EUCT) is presented with regard to the implementation of CT screening in Europe; post NLST. All seven principal investigators completed a questionnaire on the epidemiological, radiological, and nodule management aspects of their ......Overview of the European randomized lung cancer CT screening trials (EUCT) is presented with regard to the implementation of CT screening in Europe; post NLST. All seven principal investigators completed a questionnaire on the epidemiological, radiological, and nodule management aspects...

  6. Abdominal and Pelvic CT

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

  7. Computed Tomography (CT) -- Head

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

  8. Computed Tomography (CT) -- Sinuses

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

  9. Computed Tomography (CT) -- Head

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

  10. Computed Tomography (CT) -- Sinuses

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

  11. Abdominal and Pelvic CT

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

  12. Computed Tomography (CT) -- Head

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

  13. Computed Tomography (CT) -- Sinuses

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

  14. Abdominal and Pelvic CT

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

  15. Computed Tomography (CT) -- Head

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

  16. Computed Tomography (CT) -- Sinuses

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

  17. Abdominal and Pelvic CT

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

  18. Computed Tomography (CT) -- Head

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

  19. Computed Tomography (CT) -- Sinuses

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

  20. CT Grading of Otosclerosis

    National Research Council Canada - National Science Library

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

    2009-01-01

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

  1. Abdominal and Pelvic CT

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

  2. Computed Tomography (CT) -- Head

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

  3. Computed Tomography (CT) -- Sinuses

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

  4. Abdominal and Pelvic CT

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

  5. Computed Tomography (CT) -- Head

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

  6. Computed Tomography (CT) -- Sinuses

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

  7. Abdominal and Pelvic CT

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

  8. Computed Tomography (CT) -- Head

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

  9. Abdominal and Pelvic CT

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

  10. Computed Tomography (CT) -- Sinuses

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

  11. Computed Tomography (CT) -- Sinuses

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

  12. Computed Tomography (CT) -- Head

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

  13. Abdominal and Pelvic CT

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

  14. Abdominal and Pelvic CT

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

  15. Computed Tomography (CT) -- Sinuses

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

  16. Abdominal and Pelvic CT

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

  17. Computed Tomography (CT) -- Head

    Medline Plus

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

  18. Computed Tomography (CT) -- Head

    Medline Plus

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

  19. Computed Tomography (CT) -- Head

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

  20. Computed Tomography (CT) -- Sinuses

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

  1. Cardiac CT Scan

    Science.gov (United States)

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

  2. Computed Tomography (CT) -- Head

    Medline Plus

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

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

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

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

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

  5. Gallstone ileus: CT findings

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-01

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

  6. Abdominal and Pelvic CT

    Medline Plus

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

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

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

  8. Computed Tomography (CT) -- Head

    Medline Plus

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

  9. Computed Tomography (CT) -- Head

    Medline Plus

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

  10. CT angiography and CT perfusion in acute ischemic stroke

    NARCIS (Netherlands)

    Seeters, T. van

    2016-01-01

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

  11. An international multicenter comparison of time-SLIP unenhanced MR angiography and contrast-enhanced CT angiography for assessing renal artery stenosis: the renal artery contrast-free trial.

    Science.gov (United States)

    Albert, Timothy S E; Akahane, Masaaki; Parienty, Isabelle; Yellin, Nancy; Catalá, Violeta; Alomar, Xavier; Prot, Antoine; Tomizawa, Nobuo; Xue, Huadan; Katabathina, Venkata S; Lopera, Jorge E; Jin, Zhengyu

    2015-01-01

    The unenhanced MR angiography (MRA) technique time-spatial labeling inversion pulse (time-SLIP) may provide a safe alternative for evaluating the renal arteries for stenosis. This international multicenter trial tested the hypothesis that time-SLIP unenhanced MRA is accurate and robust for assessing the renal arteries for stenosis in comparison with contrast-enhanced CT angiography (CTA). Four centers (United States, Europe, Asia) enrolled 75 patients (average age ± SD, 58 ± 13 years; 41 [55%] men and 34 [45%] women). Each patient underwent abdominal contrast-enhanced CTA and abdominal unenhanced MRA using time-SLIP with balanced steady-state free precession. All images were visually assessed for quality (arterial signal intensity) and for the absence or presence of renal artery stenosis (≤ 50% or > 50% stenosis, respectively). In addition, for arteries with any visible disease, the severity of the stenosis was quantified. Two blinded readers evaluated each study. No arteries were excluded from analysis. Unenhanced MRA image quality was excellent for 56 of 75 patients (75%) and good for 16 of 75 patients (21%). CTA was used as the reference standard and showed that 23 of 161 renal arteries (14.3%) had stenosis > 50%. Unenhanced MRA correctly classified 17 of the 23 renal arteries with > 50% stenosis and correctly classified 128 of the 138 renal arteries as not having disease (≤ 50% stenosis) to yield a sensitivity of 74%, specificity of 93%, and accuracy of 90% (χ(2) = 0.56; p = 0.45, no statistically significant difference). Of the 16 misclassified arteries, only three had a clinically relevant misclassification (CTA ≥ 70% stenosis and unenhanced MRA ≤ 50% stenosis or unenhanced MRA ≥ 70% stenosis and CTA ≤ 50% stenosis). On average, measured stenotic severity (n = 28 arteries) was similar for unenhanced MRA (64% ± 17%) and CTA (62% ± 16%) (p = 0.51). Compared with contrast-enhanced CTA, the unenhanced MRA technique time-SLIP shows promise for

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

    Medline Plus

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

  13. Marketing cardiac CT programs.

    Science.gov (United States)

    Scott, Jason

    2010-01-01

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

  14. CT perfusion of the liver: principles and applications in oncology.

    Science.gov (United States)

    Kim, Se Hyung; Kamaya, Aya; Willmann, Jürgen K

    2014-08-01

    With the introduction of molecularly targeted chemotherapeutics, there is an increasing need for defining new response criteria for therapeutic success because use of morphologic imaging alone may not fully assess tumor response. Computed tomographic (CT) perfusion imaging of the liver provides functional information about the microcirculation of normal parenchyma and focal liver lesions and is a promising technique for assessing the efficacy of various anticancer treatments. CT perfusion also shows promising results for diagnosing primary or metastatic tumors, for predicting early response to anticancer treatments, and for monitoring tumor recurrence after therapy. Many of the limitations of early CT perfusion studies performed in the liver, such as limited coverage, motion artifacts, and high radiation dose of CT, are being addressed by recent technical advances. These include a wide area detector with or without volumetric spiral or shuttle modes, motion correction algorithms, and new CT reconstruction technologies such as iterative algorithms. Although several issues related to perfusion imaging-such as paucity of large multicenter trials, limited accessibility of perfusion software, and lack of standardization in methods-remain unsolved, CT perfusion has now reached technical maturity, allowing for its use in assessing tumor vascularity in larger-scale prospective clinical trials. In this review, basic principles, current acquisition protocols, and pharmacokinetic models used for CT perfusion imaging of the liver are described. Various oncologic applications of CT perfusion of the liver are discussed and current challenges, as well as possible solutions, for CT perfusion are presented.

  15. Avaliação do desempenho da colonografia tomográfica computadorizada (colonoscopia virtual no diagnóstico de pólipos colorretais Evaluation of computed tomographic colonography for detection of colorectal polyps

    Directory of Open Access Journals (Sweden)

    Gustavo Kuhn Pfeifer

    2008-12-01

    Full Text Available RACIONAL: A colonografia tomográfica computadorizada tem sido proposta como teste substituto da colonoscopia para o diagnóstico de pólipos colorretais em programas de rastreamento de câncer de intestino grosso. OBJETIVO: Avaliar o desempenho da colonografia tomográfica computadorizada na detecção de pólipos colorretais, considerando a colonoscopia como padrão-ouro. MÉTODOS: Foram estudados 20 pacientes com alto risco para neoplasia colorretal (14 homens e 6 mulheres com idades médias de 55 e 59 anos, respectivamente. A colonografia tomográfica computadorizada foi realizada até 3 horas antes da colonoscopia. Um cateter com balão foi introduzido no reto com insuflação dos cólons e do reto com ar ambiente até que fosse obtida distensão satisfatória dos mesmos. Para otimizar a distensão colônica, minimizar artefatos decorrentes da peristalse e diminuir o espasmo, foram administrados 20 mg de hioscina intravenosa imediatamente antes do exame radiológico. RESULTADOS: A imagem radiológica do cólon foi considerada de qualidade satisfatória em todos os casos. A colonoscopia detectou o total de 85 pólipos em 19 dos 20 pacientes (95%. Todos os pólipos observados foram removidos e encaminhados para exame anatomopatológico. A colonografia tomográfica computadorizada identificou 8 dos 10 pólipos com diâmetros > 10 mm (80%, 2 dos 19 com diâmetro entre 5 e 9 mm (18,2%, e apenas 1 dos 53 5 mm. Destes, 8 (47% foram corretamente identificados pela colonografia tomográfica computadorizada. Nenhuma das neoplasias com diâmetros BACKGROUND: Computed tomographic colonography has been proposed for detection of colorectal polyps instead of colonoscopy in colorectal cancer screening programs. AIM: To evaluate the performance of computed tomographic colonography in the detection of colorectal polyps with colonoscopy used as the gold standard. METHODS: We prospectively studied 20 patients at high risk for colorectal neoplasia (14 men and 6

  16. Virtual colonoscopy

    Science.gov (United States)

    Colonoscopy - virtual; CT colonography; Computed tomographic colonography; Colography - virtual ... Differences between virtual and conventional colonoscopy include: VC can view the colon from many different angles. This is not as easy ...

  17. PET/CT Artifacts

    OpenAIRE

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

    2011-01-01

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

  18. FDG-PET/CT in lymphoma

    Science.gov (United States)

    D'souza, Maria M; Jaimini, Abhinav; Bansal, Abhishek; Tripathi, Madhavi; Sharma, Rajnish; Mondal, Anupam; Tripathi, Rajendra Prashad

    2013-01-01

    Lymphomas are a heterogeneous group of diseases that arise from the constituent cells of the immune system or from their precursors. 18F-fludeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is now the cornerstone of staging procedures in the state-of-the-art management of Hodgkin's disease and aggressive non-Hodgkin's lymphoma. It plays an important role in staging, restaging, prognostication, planning appropriate treatment strategies, monitoring therapy, and detecting recurrence. However, its role in indolent lymphomas is still unclear and calls for further investigational trials. The protean PET/CT manifestations of lymphoma necessitate a familiarity with the spectrum of imaging findings to enable accurate diagnosis. A meticulous evaluation of PET/CT findings, an understanding of its role in the management of lymphomas, and knowledge of its limitations are mandatory for the optimal utilization of this technique. PMID:24604942

  19. CT of Gastric Emergencies.

    Science.gov (United States)

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

    2015-01-01

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

  20. Computed Tomography (CT) -- Head

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

  1. Abdominal and Pelvic CT

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

  2. Computed Tomography (CT) -- Sinuses

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

  3. Computed Tomography (CT) -- Sinuses

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

  4. Computed Tomography (CT) -- Sinuses

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

  5. Computed Tomography (CT) -- Head

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

  6. Computed Tomography (CT) -- Head

    Science.gov (United States)

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

  7. CT of tracheal agenesis

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-09-15

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

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

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

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

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

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

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

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

    Science.gov (United States)

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

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

    Medline Plus

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

  13. Dark-lumen MR colonography with fecal tagging: a comparison of water enema and air methods of colonic distension for detecting colonic neoplasms

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Gomez, Sonia; Pages Llinas, Mario; Juan Garcia, Carmen de; Rimola Gibert, Jordi; Ayuso Colella, Juan R.; Ayuso Colella, Carmen [Hospital Clinico of Barcelona, Department of Radiology, Barcelona (Spain); Castells Garangou, Antoni; Bordas Alsina, Josep M. [Hospital Clinico of Barcelona, Department of Gastroenterology, Barcelona (Spain)

    2008-07-15

    The purpose was to evaluate MR colonography (MRC) with barium fecal tagging in detecting colorectal pathology and to determine how air-based and water-based colonic distension influences MRC. We studied 83 patients with high risk of colonic neoplasms. All received oral barium sulfate for colonic preparation before unenhanced and enhanced T1-weighted gradient-echo MRC using either water (n=54) or air (n=29) for colonic distension. Fecal tagging, distension, and artifacts were recorded. All patients underwent conventional colonoscopy within 2 weeks of MRC; the techniques were compared for detection of malignant neoplasms and polyps {>=}1 cm, 6-9 mm, and {<=}5 mm. Fecal tagging was ''good'' in 76% of the colonic segments in water-distended patients and 46% of air-distended patients. The degree of distension was ''good'' in 90.7% of water-distended patients and 44% of air-distended patients. Severe artifacts were present in 15% air-distended patients and 0.3% of water-distended patients. Both water-distended and air-distended MRC detected all malignant neoplasms and polyps {>=}1 cm, but more air-distended MRC were excluded for poor quality. MRC with fecal tagging is useful for detecting lesions {>=}1 cm. Air distension was inferior to water distension in most aspects. Water-based colonic distension should be used for barium-tagging MRC. (orig.)

  14. Clinical indications for computed tomographic colonography: European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline

    Energy Technology Data Exchange (ETDEWEB)

    Spada, Cristiano; Barbaro, Federico; Petruzziello, Lucio [Catholic University, Digestive Endoscopy Unit, Rome (Italy); Stoker, Jaap; Haan, Margriet C. de [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Alarcon, Onofre [Universidad de La Laguna, Department of Gastroenterology, Hospital Universitario de Canarias, Facultad de Medicina, La Laguna, Tenerife (Spain); Bellini, Davide; Laghi, Andrea [Sapienza University of Rome, I.C.O.T. Hospital, Department of Radiological Sciences, Oncology and Pathology, Latina (Italy); Bretthauer, Michael [Oslo University Hospital, Department of Health Economy and Health Management, University of Oslo, and Department of Transplantation Medicine, Gastroenterology Unit, Oslo (Norway); Dumonceau, Jean-Marc [Gedyt Endoscopy Center, Buenos Aires (Argentina); Ferlitsch, Monika [Medical University of Vienna, Department of Internal Medicine III, Division of Gastroenterology and Hepatology, Vienna (Austria); Halligan, Steve; Helbren, Emma; Plumb, Andrew; Taylor, Stuart A. [University College London, Centre for Medical Imaging, London (United Kingdom); Hellstrom, Mikael [Sahlgrenska University Hospital and Sahlgrenska Academy at University of Gothenburg, Department of Radiology, Gothenburg (Sweden); Kuipers, Ernst J. [Erasmus MC University Medical Center, Department of Gastroenterology and Hepatology, Rotterdam (Netherlands); Lefere, Philippe [Virtual Colonoscopy Teaching Centre, Hooglede (Belgium); AZ Delta, Roeselare (Belgium); Mang, Thomas [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Neri, Emanuele [University of Pisa, Diagnostic and Interventional Radiology, Pisa (Italy); Regge, Daniele [Institute for Cancer Research and Treatment, Candiolo-Torino (Italy); Hassan, Cesare [Catholic University, Digestive Endoscopy Unit, Rome (Italy); Ospedale Nuovo Regina Margherita, Department of Gastroenterology, Rome (Italy)

    2014-10-03

    Colorectal cancer (CRC) is a major cause of morbidity and mortality [1, 2]. CRC screening by fecal occult blood testing (FOBT) has been shown to reduce CRC mortality [3, 4], and is currently used in several European countries. Colonoscopy is highly effective for detecting advanced neoplasia, and endoscopic polypectomy reduces subsequent CRCspecific incidence and mortality [5]. In Europe, colonoscopy is mainly used to investigate FOBT-positive or symptomatic patients, or as a preventive strategy in those with increased CRC risk [6]. Computed tomographic colonography (CTC) is a minimally invasive imaging technique that is highly accurate for detecting colorectal cancer (CRC) and adenomatous polyps. The technique is standardized [7], and CTC is more easily performed than barium enema. Evidence-based data suggest that CTC is the natural replacement for barium enema and a complementary rather than an alternative examination to colonoscopy. However, the clinical scenarios for which CTC is indicated remain unclear. To address this uncertainty - 20 years after the first presentation of CTC at a radiological meeting [8] - the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) decided to produce a common guideline regarding indications for CTC in clinical practice. Technical and quality issues of CTC have been deliberately excluded from this work as these have already been discussed separately [7].

  15. CT scan of choristoma

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-02-01

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

  16. Variation in quantitative CT air trapping in heavy smokers on repeat CT examinations

    Energy Technology Data Exchange (ETDEWEB)

    Mets, Onno M.; Gietema, Hester A.; Jong, Pim A. de [University Medical Center Utrecht, Radiology, Heidelberglaan 100, Postbus 85500, Utrecht (Netherlands); Isgum, Ivana; Mol, Christian P. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Zanen, Pieter [University Medical Center Utrecht, Pulmonology, Utrecht (Netherlands); Prokop, Mathias [Radboud University Nijmegen Medical Centre, Radiology, Nijmegen (Netherlands); University Medical Center Utrecht, Radiology, Heidelberglaan 100, Postbus 85500, Utrecht (Netherlands)

    2012-12-15

    To determine the variation in quantitative computed tomography (CT) measures of air trapping in low-dose chest CTs of heavy smokers. We analysed 45 subjects from a lung cancer screening trial, examined by CT twice within 3 months. Inspiratory and expiratory low-dose CT was obtained using breath hold instructions. CT air trapping was defined as the percentage of voxels in expiratory CT with an attenuation below -856 HU (EXP{sub -856}) and the expiratory to inspiratory ratio of mean lung density (E/I-ratio{sub MLD}). Variation was determined using limits of agreement, defined as 1.96 times the standard deviation of the mean difference. The effect of both lung volume correction and breath hold reproducibility was determined. The limits of agreement for uncorrected CT air trapping measurements were -15.0 to 11.7 % (EXP{sub -856}) and -9.8 to 8.0 % (E/I-ratio{sub MLD}). Good breath hold reproducibility significantly narrowed the limits for EXP{sub -856} (-10.7 to 7.5 %, P = 0.002), but not for E/I-ratio{sub MLD} (-9.2 to 7.9 %, P = 0.75). Statistical lung volume correction did not improve the limits for EXP{sub -856} (-12.5 to 8.8 %, P = 0.12) and E/I-ratio{sub MLD} (-7.5 to 5.8 %, P = 0.17). Quantitative air trapping measures on low-dose CT of heavy smokers show considerable variation on repeat CT examinations, regardless of lung volume correction or reproducible breath holds. (orig.)

  17. Computed Tomography (CT) -- Sinuses

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

  18. Computed Tomography (CT) -- Head

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

  19. Computed Tomography (CT) -- Sinuses

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

  20. Computed Tomography (CT) -- Head

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

  1. Abdominal and Pelvic CT

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

  2. Abdominal and Pelvic CT

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

  3. Abdominal and Pelvic CT

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

  4. Computed Tomography (CT) -- Head

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

  5. Computed Tomography (CT) -- Sinuses

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

  6. CT Angiography (CTA)

    Science.gov (United States)

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

  7. Computed Tomography (CT) -- Sinuses

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

  8. Abdominal and Pelvic CT

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    Full Text Available ... CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ... to you, revolve around you during the imaging process. You will be alone in the exam room ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ... to you, revolve around you during the imaging process. You will be alone in the exam room ...

  10. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... The teddy bear denotes child-specific content. Related Articles and Media Magnetic Resonance Imaging (MRI) - Head Head and Neck Cancer Treatment Radiation Dose in X-Ray and CT ...

  11. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ...

  12. Computed Tomography (CT) -- Head

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    Full Text Available ... time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ...

  13. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... Magnetic Resonance Imaging (MRI) - Head Head and Neck Cancer Treatment Radiation Dose in X-Ray and CT Exams Contrast Materials Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation ...

  14. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... hours prior to your exam. Leave jewelry at home and wear loose, comfortable clothing. You may be ... the CT images and should be left at home or removed prior to your exam. You may ...

  15. Computed Tomography (CT) -- Head

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    Full Text Available ... hours prior to your exam. Leave jewelry at home and wear loose, comfortable clothing. You may be ... the CT images and should be left at home or removed prior to your exam. You may ...

  16. Abdominal and Pelvic CT

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    Full Text Available ... hours prior to your exam. Leave jewelry at home and wear loose, comfortable clothing. You may be ... the CT images and should be left at home or removed prior to your exam. You may ...

  17. Abdominal and Pelvic CT

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    Full Text Available ... liver, shows up in shades of gray, and air appears black. With CT scanning, numerous x-ray ... cause blurring of the images and degrade the quality of the examination the same way that it ...

  18. Computed Tomography (CT) -- Head

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    Full Text Available ... liver, shows up in shades of gray, and air appears black. With CT scanning, numerous x-ray ... cause blurring of the images and degrade the quality of the examination the same way that it ...

  19. Abdominal and Pelvic CT

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    Full Text Available ... tomography (CT) scan View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  2. Abdominal and Pelvic CT

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

  3. Abdominal and Pelvic CT

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    Full Text Available ... your exam. You should inform your physician of all medications you are taking and if you have ... body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a ...

  4. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... your exam. You should inform your physician of all medications you are taking and if you have ... body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a ...

  5. Computed Tomography (CT) -- Head

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    Full Text Available ... your exam. You should inform your physician of all medications you are taking and if you have ... body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a ...

  6. Abdominal and Pelvic CT

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    Full Text Available ... or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect. Women ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect. The ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  8. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect. Women ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... additional view capabilities. Modern CT scanners are so fast that they can scan through large sections of ... remain still during the exam. Many scanners are fast enough that children can be scanned without sedation. ...

  10. Pediatric CT Scans

    Science.gov (United States)

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

  11. Abdominal and Pelvic CT

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    Full Text Available ... or liver cirrhosis. cancers of the liver, kidneys, pancreas, ovaries and bladder as well as lymphoma. kidney ... and organs such as the liver, kidneys and pancreas. When you enter the CT scanner, special light ...

  12. Abdominal and Pelvic CT

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

  13. Computed Tomography (CT) -- Sinuses

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

  14. Computed Tomography (CT) -- Head

    Science.gov (United States)

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

  15. Computed Tomography (CT) -- Head

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

  16. Abdominal and Pelvic CT

    Science.gov (United States)

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

  17. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ... of many areas of the body, particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by ...

  18. Abdominal and Pelvic CT

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    Full Text Available ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ... of many areas of the body, particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by ...

  19. Abdominal and Pelvic CT

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    Full Text Available ... to arriving. top of page What will I experience during and after the procedure? CT exams are ... at most a minute or two. You may experience a sensation like you have to urinate; however, ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... 10 minutes. top of page What will I experience during and after the procedure? CT exams are ... at most a minute or two. You may experience a sensation like you have to urinate; however, ...

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... 10 minutes. top of page What will I experience during and after the procedure? CT exams are ... at most a minute or two. You may experience a sensation like you have to urinate; however, ...

  2. Computed Tomography (CT) -- Sinuses

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

  3. Computed Tomography (CT) -- Head

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    Full Text Available ... See the Safety page for more information about pregnancy and x-rays. top of page What does ... See the Safety page for more information about pregnancy and x-rays. CT scanning is, in general, ...

  4. Abdominal and Pelvic CT

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    Full Text Available ... See the Safety page for more information about pregnancy and x-rays. top of page What does ... See the Safety page for more information about pregnancy and x-rays. CT scanning is, in general, ...

  5. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... See the Safety page for more information about pregnancy and x-rays. top of page What does ... See the Safety page for more information about pregnancy and x-rays. CT scanning is, in general, ...

  6. Abdominal and Pelvic CT

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    Full Text Available ... Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal Cancer top of page This page was reviewed on ... GI Tract X-ray (Radiography) - Upper GI Tract Colorectal Cancer Images related to Computed Tomography (CT) - Abdomen and ...

  7. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... rays used in CT scans should have no immediate side effects. Risks There is always a slight ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  8. Computed Tomography (CT) -- Head

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    Full Text Available ... rays used in CT scans should have no immediate side effects. Risks There is always a slight ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  9. Abdominal and Pelvic CT

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    Full Text Available ... rays used in CT scans should have no immediate side effects. Risks There is always a slight ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than ...

  11. Abdominal and Pelvic CT

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    Full Text Available ... tissue as well as the lungs, bones, and blood vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. ...

  12. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... tissue as well as the lungs, bones, and blood vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. ...

  13. Abdominal and Pelvic CT

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    Full Text Available ... during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and ... may increase the risk of an unusual adverse effect. Women should always inform their physician and the ...

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and ... may increase the risk of an unusual adverse effect. The radiologist also should know if you have ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and ... may increase the risk of an unusual adverse effect. Women should always inform their physician and the ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to ... time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be ...

  17. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to ... time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be ...

  18. Abdominal and Pelvic CT

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    Full Text Available ... often used to determine the cause of unexplained pain. CT scanning is fast, painless, noninvasive and accurate. ... help diagnose the cause of abdominal or pelvic pain and diseases of the internal organs, small bowel ...

  19. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... generated during a CT scan can be reformatted in multiple planes, and can even generate three-dimensional ... hours beforehand, as contrast material will be used in your exam. You should inform your physician of ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... or to plan radiation therapy for brain cancer. In emergency cases, it can reveal internal injuries and ... generated during a CT scan can be reformatted in multiple planes, and can even generate three-dimensional ...

  1. Computed Tomography (CT) -- Head

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    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... contrast materials and a metallic taste in your mouth that lasts for at most a minute or ...

  2. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... contrast materials and a metallic taste in your mouth that lasts for at most a minute or ...

  3. Abdominal and Pelvic CT

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    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... contrast materials and a metallic taste in your mouth that lasts for at most a minute or ...

  4. Abdominal and Pelvic CT

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by CT scanning may eliminate the need ...

  5. Computed Tomography (CT) -- Head

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate the need ...

  6. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by CT scanning may eliminate the need ...

  7. Abdominal and Pelvic CT

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    Full Text Available ... preferable over CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder ... Send us your feedback Did you find the information you were looking for? Yes No Please type ...

  8. Computed Tomography (CT) -- Head

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    Full Text Available ... brain cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save ... to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide ...

  9. Abdominal and Pelvic CT

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  10. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  12. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... quickly. When you enter the CT scanner, special light lines may be seen projected onto your body, ... and its references. The risk of serious allergic reaction to contrast materials that contain iodine is extremely ...

  13. Abdominal and Pelvic CT

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    Full Text Available ... pancreas. When you enter the CT scanner, special light lines may be seen projected onto your body, ... in the womb. The risk of serious allergic reaction to contrast materials that contain iodine is extremely ...

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... quickly. When you enter the CT scanner, special light lines may be seen projected onto your body, ... and its references. The risk of serious allergic reaction to contrast materials that contain iodine is extremely ...

  15. CT head in children

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-15

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

  16. Computed Tomography (CT) -- Sinuses

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

  17. Lumbosacral spine CT

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

  18. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... data suggest that it is safe to continue breastfeeding after receiving intravenous contrast. For further information please ...

  19. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... cavity and sinuses. plan for surgery by defining anatomy. top of page How should I prepare? You ... pregnancy and x-rays. CT scanning is, in general, not recommended for pregnant women unless medically necessary ...

  20. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... and accurate. It’s also the most reliable imaging technique for determining if the sinuses are obstructed and ... to obtain images. For children, the CT scanner technique will be adjusted to their size and the ...

  1. Abdominal and Pelvic CT

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    Full Text Available ... to obtain images. For children, the CT scanner technique will be adjusted to their size and the ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ...

  2. Abdominal and Pelvic CT

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

  3. Computed Tomography (CT) -- Head

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

  4. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  5. Abdominal and Pelvic CT

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    Full Text Available ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  7. Abdominal and Pelvic CT

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    Full Text Available ... emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives. Tell your ... emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has ...

  8. Abdominal and Pelvic CT

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    Full Text Available ... to remove hearing aids and removable dental work. Women will be asked to remove bras containing metal ... increase the risk of an unusual adverse effect. Women should always inform their physician and the CT ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... to remove hearing aids and removable dental work. Women will be asked to remove bras containing metal ... have diabetes —particularly if you are taking Glucophage . Women should always inform their physician and the CT ...

  10. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... to remove hearing aids and removable dental work. Women will be asked to remove bras containing metal ... increase the risk of an unusual adverse effect. Women should always inform their physician and the CT ...

  11. Abdominal and Pelvic CT

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    Full Text Available ... Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown. ... CT scan? You should wear comfortable, loose-fitting clothing to your exam. You may be given a ...

  12. Computed Tomography (CT) -- Head

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    Full Text Available ... to wear a lead apron to minimize radiation exposure. After a CT exam, the intravenous line used ... always a slight chance of cancer from excessive exposure to radiation. However, the benefit of an accurate ...

  13. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... to wear a lead apron to minimize radiation exposure. After a CT exam, the intravenous line used ... always a slight chance of cancer from excessive exposure to radiation. However, the benefit of an accurate ...

  14. Abdominal and Pelvic CT

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    Full Text Available ... to wear a lead apron to minimize radiation exposure. After a CT exam, the intravenous line used ... always a slight chance of cancer from excessive exposure to radiation. However, the benefit of an accurate ...

  15. Abdominal and Pelvic CT

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

  16. Abdominal and Pelvic CT

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

  17. Computed Tomography (CT) -- Head

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

  18. Computed Tomography (CT) -- Sinuses

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

  19. Abdominal and Pelvic CT

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

  20. Computed Tomography (CT) -- Head

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