WorldWideScience

Sample records for noncathartic ct colonography

  1. Context-specific method for detection of soft-tissue lesions in non-cathartic low-dose dual-energy CT colonography

    Science.gov (United States)

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

    2015-03-01

    In computed tomographic colonography (CTC), orally administered fecal-tagging agents can be used to indicate residual feces and fluid that could otherwise hide or imitate lesions on CTC images of the colon. Although the use of fecal tagging improves the detection accuracy of CTC, it can introduce image artifacts that may cause lesions that are covered by fecal tagging to have a different visual appearance than those not covered by fecal tagging. This can distort the values of image-based computational features, thereby reducing the accuracy of computer-aided detection (CADe). We developed a context-specific method that performs the detection of lesions separately on lumen regions covered by air and on those covered by fecal tagging, thereby facilitating the optimization of detection parameters separately for these regions and their detected lesion candidates to improve the detection accuracy of CADe. For pilot evaluation, the method was integrated into a dual-energy CADe (DE-CADe) scheme and evaluated by use of leave-one-patient-out evaluation on 66 clinical non-cathartic low dose dual-energy CTC (DE-CTC) cases that were acquired at a low effective radiation dose and reconstructed by use of iterative image reconstruction. There were 22 colonoscopy-confirmed lesions ≥6 mm in size in 21 patients. The DE-CADe scheme detected 96% of the lesions at a median of 6 FP detections per patient. These preliminary results indicate that the use of context-specific detection can yield high detection accuracy of CADe in non-cathartic low-dose DE-CTC examinations.

  2. Progressive region-based colon extraction for computer-aided detection and quantitative imaging in cathartic and non-cathartic CT colonography

    Science.gov (United States)

    Näppi, Janne J.; Ryu, Yasuji; Yoshida, Hiroyuki

    2014-03-01

    Automated colon extraction is an important first step for applications of computer-aided detection (CADe) and quantitative imaging in computed tomographic colonography (CTC). However, previously developed colon extraction algorithms have various limitations. We developed a new fully automated progressive region-based (PRB) method to extract the complete region of colon from CTC images while minimizing the presence of extra-colonic components. The method can be used to provide the target region for CADe as well as to provide quantitative imaging information about the colon. In the method, extra-colonic components are excluded from the abdominal region by use of anatomy-based extraction methods, visible lumen regions of the colon and small bowel are decomposed into material-based subregions, a colon pathway is tracked from the anus to cecum by use of algorithms of progressively increasing complexity using anatomy-based landmarks, segmental features, and region-based tracking algorithms, and the extracted lumen region is perfected into a complete lumen by use of a discrete level-set algorithm. The method was tested with 15 challenging cathartic and non-cathartic fecaltagging CTC cases. Preliminary results indicate that the PRB method can outperform our previously developed centerline-based tracking method in colon extraction.

  3. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... Radiology and You Take our survey Sponsored by Image/Video Gallery Your Radiologist Explains CT Colonography (Virtual ... to allow for inflation with air while CT images are being taken. If you’re scheduled for ...

  4. CT- and MR colonography

    DEFF Research Database (Denmark)

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

    2002-01-01

    in the supine and prone positions. Data are then downloaded to a workstation for post processing and image-analysis. RESULTS: Results have shown a high sensitivity and specificity for polyps > or = 10 mm, comparable to the sensitivity of conventional colonoscopy and superior to double contrast barium enema....... 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...

  5. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... Abdominal Ultrasound Video: Pelvic Ultrasound Medical Imaging Costs Radiology and You Take our survey Sponsored by Image/ ... Explains CT Colonography (Virtual colonoscopy) Transcript Welcome to Radiology Info dot org! Hi, I’m Dr. Elliot ...

  6. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... and You Take our survey Sponsored by Image/Video Gallery Your Radiologist Explains CT Colonography (Virtual colonoscopy) ... Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You ...

  7. CT Colonography (Virtual Colonoscopy)

    Science.gov (United States)

    ... 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 ...

  8. CT colonography: Techniques, indications, findings

    International Nuclear Information System (INIS)

    Mang, Thomas; Graser, Anno; Schima, Wolfgang; Maier, Andrea

    2007-01-01

    Computed tomographic colonography (CTC) is a minimally invasive technique for imaging the entire colon. Based on a helical thin-section CT of the cleansed and air-distended colon, two-dimensional and three-dimensional projections are used for image interpretation. Several clinical improvements in patient preparation, technical advances in CT, and new developments in evaluation software have allowed CTC to develop into a powerful diagnostic tool. It is already well established as a reliable diagnostic tool in symptomatic patients. Many experts currently consider CTC a comparable alternative to conventional colonoscopy, although there is still debate about its sensitivity for the detection of colonic polyps in a screening population. This article summarizes the main indications, the current techniques in patient preparation, data acquisition and data analysis as well as imaging features for common benign and malignant colorectal lesions

  9. Clinical application of helical CT colonography

    International Nuclear Information System (INIS)

    Zeng Huiliang; Zhu Xinjin; Liang Rujian; Liang Jianhao; Ou Weiqian; Wen Haomao

    2009-01-01

    Objective: To investigate the clinical value of 16-slice helical CT colonography in the diagnosis of colon tumor and polypus. Methods: 16-slice helical CT volumetric scanning was performed in 18 patients with colonic disease, including colonic tumor (n=16) and colonic polypus (n=2). 3D images, virtual endoscopy and multiplanar reformation were obtained in the AW4.1 workstation. CT appearances were compared with operation and fiberoptic colonoscopy. Results: Satisfied results were achieved from 18 patients, no difference found in results between CT colonography and operation in 16 patients with colonic tumor. Conclusion: 16-slice helical CT colonography is of great value in preoperative staging of colonic tumor and have a high value in clinical application. (authors)

  10. Spiral CT colonography in inflammatory bowel disease

    International Nuclear Information System (INIS)

    Tarjan, Zsolt; Zagoni, Tamas; Gyoerke, Tamas; Mester, Adam; Karlinger, Kinga; Mako, Erno K.

    2000-01-01

    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

  11. Diverticular disease in CT colonography

    International Nuclear Information System (INIS)

    Lefere, P.; Gryspeerdt, S.; Baekelandt, M.; Holsbeeck, B. van; Dewyspelaere, J.

    2003-01-01

    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.)

  12. 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.)

  13. Clinical study of CT colonography

    International Nuclear Information System (INIS)

    Nakazawa, Saburo; Hattori, Toshiyuki; Inui, Kazuo

    2011-01-01

    We studied the usefulness of CT colonography (CTC) for colon cancer diagnosis. CTC and optical colonoscopy were performed for 150 cases mainly including patients with a positive fecal occult blood test (FOBT). The results were compared and analyzed. The following are the final diagnoses given to the patients: advanced colon cancer: 41 cases; early cancer: 25 cases; adenoma: 74 cases; hyperplasia: 3 cases; submucosal tumor: 1 case; and no lesion: 6 cases. In terms of diagnostic performance of CTC, accuracy was found to be 96%, sensitivity was found to be 97.9%, and specificity was found to be 50%. Cancer stage-specific sensitivity was as follows: advanced colon cancer: 100%; early cancer: 96.3%; adenoma: 71.2%; and hyperplasia: 47.4%. Lesion site-specific sensitivity was as follows: caecum: 76.2%; ascending colon: 57.6%; transverse colon: 66.2%; descending colon: 83.3%; sigmoid colon: 85.1%; and rectum: 78.0%. Lesion size-specific sensitivity was as follows: 2 to 5 mm: 56.7%; 6 to 9 mm: 88.1%; 10 mm or more: 92.5%; and 6 mm or more: 90.9%. Therefore, the diagnostic sensitivity of CTC was confirmed to be high. The results suggest that CTC would be useful for colon cancer screening. (author)

  14. Diverticular disease in CT colonography.

    Science.gov (United States)

    Lefere, Philippe; Gryspeerdt, Stefaan; Baekelandt, Marc; Dewyspelaere, Jef; van Holsbeeck, B

    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 (> or = 1 cm) is suspected.

  15. Electronic cleansing for visualization in CT colonography

    OpenAIRE

    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.

  16. CT colonography in faecal occult blood test positives

    NARCIS (Netherlands)

    Liedenbaum, M.H.

    2010-01-01

    CT colonography is a non-invasive imaging technique to visualise the colon. The colon is insufflated with CO2 or air and a CT-scan of the abdomen is performed. The performance of CT colonography is nearly equal to that of colonoscopy in the detection of large colonic polyps and carcinomas. This

  17. 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

  18. CAD for CT colonography: toward a preparation-independent scheme

    International Nuclear Information System (INIS)

    Naeppi, J.

    2007-01-01

    Computer-aided detection (CAD) systems can be used to automatically detect and display the locations of polyps and masses in computed tomographic colonography (CTC) data for assisting radiologists' image interpretation. Rapid technical advancements over the last few years have established a fundamental CAD scheme for CTC that includes the steps of colon extraction, polyp detection, and false-positive (FP) reduction. Several CAD prototype systems have demonstrated clinically acceptable high polyp detection sensitivity with relatively few FP detections in cathartic CTC, and observer studies have demonstrated the potential benefit of such systems in improving the accuracy and consistency of radiologists' detection performance. Some CAD prototype systems have also demonstrated promising performance in reduced cathartic and non-cathartic CTC. Recent advancements suggest that CAD systems can soon be expected to provide a preparation-independent scheme that can yield consistently high detection sensitivity with moderately low FP rate not only with cathartic CTC protocols but over a wide range of cathartic, reduced cathartic, and non-cathartic CTC protocols. (orig.)

  19. The second ESGAR consensus statement on CT colonography

    NARCIS (Netherlands)

    Neri, Emanuele; Halligan, Steve; Hellström, Mikael; Lefere, Philippe; Mang, Thomas; Regge, Daniele; Stoker, Jaap; Taylor, Stuart; Laghi, Andrea

    2013-01-01

    To update quality standards for CT colonography based on consensus among opinion leaders within the European Society of Gastrointestinal and Abdominal Radiology (ESGAR). A multinational European panel of nine members of the ESGAR CT colonography Working Group (representing six EU countries) used a

  20. Bowel wall visualisation at CT colonography

    International Nuclear Information System (INIS)

    Svensson, M.H.; Hellstroem, M.; Svensson, E.

    2002-01-01

    Purpose: To evaluate the quality of bowel wall visualisation at CT colonography and the impact of examination in the supine and prone positions. Material and Methods: After bowel preparation, 111 patients underwent CT colonography. Air distension, degree of fluid redistribution with change in body position (supine and prone), influence of residual stool on bowel wall assessability, and quality of overall colon visualisation were evaluated using scales. Results: Thirty of 110 patients (27%) had complete overall visualisation of the colon wall and 52 (47%) had subtotal visualisation of a limited part of the colon. The entire colon was more often air-filled in the prone position (46%) than in the supine position (18%). Joint review of supine and prone data showed that for all colon segments, except the sigmoid (86%), 95% of the patients had complete air filling. All patients had residual fluid. In 75% to 99%, depending on segment, fluid did not interfere with the bowel wall visualisation in the combined evaluation of supine and prone data sets. Thirty-one patients had residual stool with potential negative influence on polyp detection. Conclusions: The colon wall was completely, or almost completely, visualised in 75% of the patients, and examination in the supine and prone positions was necessary for complete visualisation

  1. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... be performed with the most accuracy. If you have any questions about the prep, speak to your ... same day in most cases. Perhaps you might have some concerns about CT scanning. However, it’s important ...

  2. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... 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 ...

  3. Your Radiologist Explains CT Colonography

    Medline Plus

    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 ...

  4. Your Radiologist Explains CT Colonography

    Medline Plus

    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 ...

  5. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... commonly known, virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test that is used to screen the large intestine or colon for cancer and growths called polyps. This procedure uses low-dose CT or CAT scanning ... Disorders Video: The Basketball Game: An ...

  6. CT colonography at different radiation dose levels: Feasibility of dose reduction

    NARCIS (Netherlands)

    van Gelder, Rogier E.; Venema, Henk W.; Serlie, Iwo W. O.; Nio, C. Yung; Determann, Rogier M.; Tipker, Corinne A.; Vos, Frans M.; Glas, Afina S.; Bartelsman, Joep F. W.; Bossuyt, Patrick M. M.; Laméris, Johan S.; Stoker, Jaap

    2002-01-01

    PURPOSE: To investigate the sensitivity and specificity of polyp detection and the image quality of computed tomographic (CT) colonography at different radiation dose levels and to study effective doses reported in literature on CT colonography. MATERIALS AND METHODS: CT colonography and colonoscopy

  7. Colonic surveillance by CT colonography using axial images only

    International Nuclear Information System (INIS)

    Bruzzi, John F.; Brennan, Darren D.; Fenlon, Helen M.; Moss, Alan C.; MacMathuna, Padraic

    2004-01-01

    Patients at increased risk of colon cancer require strict colon surveillance. Our objective was to establish the efficacy of 2D axial CT colonography as a surveillance test when performed in routine clinical practice. Eighty-two patients at increased risk of colon cancer underwent CT colonography followed by conventional colonoscopy on the same morning. CT colonography studies were performed on a four-ring multidetector CT scanner (100 mAs, 120 kVp, 4 x 2.5 collimation) and were interpreted by two radiologists using 2D axial images only. Results were correlated with findings at colonoscopy. Note was made of subsequent histology reports from polypectomy specimens. A total of 52 polyps were detected at colonoscopy. Using 2D axial images alone, with no recourse to 2D multiplanar or 3D views, the sensitivity of CT colonography was 100, 33 and 19% for polyps larger than 9, 6-9 and smaller than 6 mm, respectively. Per-patient specificities were 98.8, 96 and 81.5%, respectively. Twenty-nine percent of polyps smaller than 1 cm were adenomatous and there were no histological features of severe dysplasia. CT colonography is a useful colon surveillance tool for patients at increased risk of colon cancer. It has a high specificity for identifying patients who should proceed to colonoscopy and polypectomy, while allowing further colon examination to be deferred in patients with normal studies. Using 2D axial images only, CT colonography can be performed as part of the daily CT workload, with a very low rate of referral for unnecessary colonoscopy. (orig.)

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

    International Nuclear Information System (INIS)

    Taylor, Stuart A.; Burling, David; Morley, Simon; Bartram, Clive I.; Halligan, Steve; Bassett, Paul; Atkin, Wendy

    2004-01-01

    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.)

  9. 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

  10. CT colonography: current status in Europe and future perspectives

    International Nuclear Information System (INIS)

    Lefere, P.; Gryspeerdt, S.; Yoshida, H.

    2007-01-01

    In this article, we review the current status of CT colonography (CTC) in Europe and future perspectives of CTC including fecal tagging and CAD. There are several large multi-centre studies that have been initiated. Fecal tagging has gradually become a prerequisite to perform state-of-the-art CTC. However, CAD for fecal-tagging CTC remains a subject for future research. (orig.)

  11. Comparison of polyp size and volume at CT colonography: implications for follow-up CT colonography.

    Science.gov (United States)

    Bethea, Emily; Nwawka, Ogonna K; Dachman, Abraham H

    2009-12-01

    The purpose of this study was to evaluate the reliability of polyp measurements at CT colonography and the factors that affect the measurements. Fifty colonoscopically proven cases of polyps 6 mm in diameter or larger were analyzed by two observers who measured each polyp in supine and prone views. Manual measurements of 2D volume by summation of areas, 2D maximum diameter, and 3D maximum diameter and automated measurements of 3D maximum diameter and volume were recorded for each observer and were repeated for one of the observers. Intraobserver and interobserver agreement was calculated. Analysis was performed to determine the measurement parameter that correlated most with summation-of-areas volume. Supine and prone measurements as a surrogate for tracking change in polyp size over time were analyzed to determine the measurement parameter with the least variation. Maximum diameter measured manually on 3D images had the highest correlation with summation-of-areas volume. Manual summation-of-areas volume was found to have the least variation between supine and prone measurements. Linear polyp measurement in the 3D endoluminal view appears to be the most reliable parameter for use in the decision to excise a polyp according to current guidelines. In our study, manual calculation of volume with summation of areas was found to be the most reliable measurement parameter for observing polyp growth over serial examinations. High reliability of polyp measurements is essential for adequate assessment of change in polyp size over serial examinations because many patients with intermediate-size polyps are expected to choose surveillance.

  12. 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.

  13. Extra colonic Findings on CT Colonography in Symptomatic Patients

    International Nuclear Information System (INIS)

    Drahovska, I.; Nigut, F.; Mach, P.; Lazurova, I.; Gombosova, L.

    2011-01-01

    The paper is an analysis of the consequences of the extra colonic findings identified on CT colonography examination of symptomatic patients and the validity of the intravenous application of contrast medium in this examination. The authors enrolled 252 patients, who underwent CT colonogprahy.128 extra colonic findings was identified in 80 patients (31.74%). The average age was 65.62 years (SD = 12.7, min. age was 29, max. age. 85 years). According the clinical significance the extra colonic findings have been divided into three groups – low, moderate and very important extra colonic findings. Low significant findings were 68 (53.12%), moderate 26 (20.31%) and very important extra colonic findings were 34 (26.56%), of which 30 were malignant nature. (author)

  14. CT colonography and colonoscopy: Assessment of patient preference in a 5-week follow-up study

    NARCIS (Netherlands)

    van Gelder, Rogier E.; Birnie, Erwin; Florie, Jasper; Schutter, Michiel P.; Bartelsman, Joep F.; Snel, Pleun; Laméris, Johan S.; Bonsel, Gouke J.; Stoker, Jaap

    2004-01-01

    PURPOSE: To prospectively evaluate short- and midterm patient preference of computed tomographic (CT) colonography relative to colonoscopy in patients at increased risk for colorectal cancer and to elucidate determinants of preference. MATERIALS AND METHODS: Consecutive patients at increased risk

  15. Reducing image noise in computed tomography (CT) colonography: effect of an integrated circuit CT detector.

    Science.gov (United States)

    Liu, Yu; Leng, Shuai; Michalak, Gregory J; Vrieze, Thomas J; Duan, Xinhui; Qu, Mingliang; Shiung, Maria M; McCollough, Cynthia H; Fletcher, Joel G

    2014-01-01

    To investigate whether the integrated circuit (IC) detector results in reduced noise in computed tomography (CT) colonography (CTC). Three hundred sixty-six consecutive patients underwent clinically indicated CTC using the same CT scanner system, except for a difference in CT detectors (IC or conventional). Image noise, patient size, and scanner radiation output (volume CT dose index) were quantitatively compared between patient cohorts using each detector system, with separate comparisons for the abdomen and pelvis. For the abdomen and pelvis, despite significantly larger patient sizes in the IC detector cohort (both P noise was significantly lower (both P 0.18). Based on the observed image noise reduction, radiation dose could alternatively be reduced by approximately 20% to result in similar levels of image noise. Computed tomography colonography images acquired using the IC detector had significantly lower noise than images acquired using the conventional detector. This noise reduction can permit further radiation dose reduction in CTC.

  16. CT colonography: interpretative performance in a non-academic environment

    International Nuclear Information System (INIS)

    Burling, D.; Halligan, S.; Atchley, J.; Dhingsar, R.; Guest, P.; Hayward, S.; Higginson, A.; Jobling, C.; Kay, C.; Lilford, R.; Maskell, G.; McCafferty, I.; McGregor, J.; Morton, D.; Kumar Neelala, M.; Noakes, M.; Philips, A.; Riley, P.; Taylor, A.; Bassett, P.; Wardle, J.; Atkin, W.; Taylor, S.A.

    2007-01-01

    Aim: To investigate interpretative accuracy and reporting time for radiologists performing computed tomography (CT) colonography in day-to-day non-academic clinical practice. Materials and methods: Thirteen radiologists from seven centres, who were reporting CT colonography in non-academic daily clinical practice, interpreted a dataset of 15 colonoscopically validated cases in a controlled environment. Ten cases had either a cancer or polyp >10 mm; one case had a medium polyp and four were normal. Correct case categorization and interpretation times were compared using analysis of variance to aggregated results obtained from both experienced observers and observers recently trained using 50 cases, working in an academic environment. The effect of experience was determined using Spearman's rank correlation. Results: Individual accuracy was highly variable, range 53% (95% CI 27-79%) to 93% (95% CI 68-100%). Mean accuracy overall was significantly inferior to experienced radiologists (mean 75 versus 88%, p = 0.04) but not significantly different from recently trained radiologists (p = 0.48). Interpretation time was not significantly different to experienced readers (mean 12.4 min versus 11.7, p = 0.74), but shorter than recently trained radiologists (p = 0.05). There was a significant, positive, linear correlation between prior experience and accuracy (p < 0.001) with no plateau. Conclusion: Accuracy for sub-specialist radiologists working in a non-academic environment is, on average, equivalent to radiologists trained using 50 cases. However, there is wide variability in individual performance, which generally falls short of the average performance suggested by meta-analysis of published data. Experience improves accuracy, but alone is insufficient to determine competence

  17. Reasons for Participation and Nonparticipation in Colorectal Cancer Screening: A Randomized Trial of Colonoscopy and CT Colonography

    NARCIS (Netherlands)

    de Wijkerslooth, Thomas R.; de Haan, Margriet C.; Stoop, Esther M.; Bossuyt, Patrick M.; Thomeer, Maarten; van Leerdam, Monique E.; Essink-Bot, Marie-Louise; Fockens, Paul; Kuipers, Ernst J.; Stoker, Jaap; Dekker, Evelien

    2012-01-01

    OBJECTIVES: We compared reported reasons for participation and nonparticipation in colorectal cancer (CRC) screening between colonoscopy and computed tomographic (CT) colonography in a randomized controlled trial. METHODS: We randomly invited 8,844 people for screening by colonoscopy or CT

  18. 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.)

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

    International Nuclear Information System (INIS)

    Ridge, C.A.; Carter, M.R.; Ryan, R.; Hegarty, C.; Malone, D.E.; Browne, L.P.; Schaffer, K.

    2011-01-01

    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.)

  20. 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.

    2010-01-01

    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 (palgorithm than by the one-step for 63% of all possible operating points. While operating at a suitable sensitivity level such as 90.8% (79/87) or 88.5% (77/87), the false positive rate was reduced by 24.4% (95% confidence intervals 17.9–31.0%) or 45.8% (95% confidence intervals 40.1–51.0%) respectively. We demonstrated that, with a proper experimental design, the Pareto optimization process can effectively help in fine-tuning and redesigning polyp detection algorithms. PMID:20548966

  1. 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.

  2. 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

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

    Science.gov (United States)

    Laghi, Andrea; Rengo, Marco; Graser, Anno; Iafrate, Franco

    2013-08-01

    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 (≥10mm) accurately detected and small lesions (6-9mm) 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 colonic

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

    International Nuclear Information System (INIS)

    Laghi, Andrea; Rengo, Marco; Graser, Anno; Iafrate, Franco

    2013-01-01

    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

  5. Electronic cleansing for 24-h limited bowel preparation CT colonography using principal curvature flow

    NARCIS (Netherlands)

    van Ravesteijn, Vincent F.; Boellaard, Thierry N.; van der Paardt, Marije P.; Serlie, Iwo W. O.; de Haan, Margriet C.; Stoker, Jaap; van Vliet, Lucas J.; Vos, Frans M.

    2013-01-01

    CT colonography (CTC) is one of the recommended methods for colorectal cancer screening. The subject's preparation is one of the most burdensome aspects of CTC with a cathartic bowel preparation. Tagging of the bowel content with an oral contrast medium facilitates CTC with limited bowel

  6. 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.

  7. 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.

  8. 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.)

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

    International Nuclear Information System (INIS)

    Bruzzi, John F.; Brennan, Darren D.; Fenlon, Helen M.; Moss, Alan C.; MacMathuna, Padraic

    2003-01-01

    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.)

  10. Automated image-based colon cleansing for laxative-free CT colonography computer-aided polyp detection

    International Nuclear Information System (INIS)

    Linguraru, Marius George; Panjwani, Neil; Fletcher, Joel G.; Summer, Ronald M.

    2011-01-01

    Purpose: To evaluate the performance of a computer-aided detection (CAD) system for detecting colonic polyps at noncathartic computed tomography colonography (CTC) in conjunction with an automated image-based colon cleansing algorithm. Methods: An automated colon cleansing algorithm was designed to detect and subtract tagged-stool, accounting for heterogeneity and poor tagging, to be used in conjunction with a colon CAD system. The method is locally adaptive and combines intensity, shape, and texture analysis with probabilistic optimization. CTC data from cathartic-free bowel preparation were acquired for testing and training the parameters. Patients underwent various colonic preparations with barium or Gastroview in divided doses over 48 h before scanning. No laxatives were administered and no dietary modifications were required. Cases were selected from a polyp-enriched cohort and included scans in which at least 90% of the solid stool was visually estimated to be tagged and each colonic segment was distended in either the prone or supine view. The CAD system was run comparatively with and without the stool subtraction algorithm. Results: The dataset comprised 38 CTC scans from prone and/or supine scans of 19 patients containing 44 polyps larger than 10 mm (22 unique polyps, if matched between prone and supine scans). The results are robust on fine details around folds, thin-stool linings on the colonic wall, near polyps and in large fluid/stool pools. The sensitivity of the CAD system is 70.5% per polyp at a rate of 5.75 false positives/scan without using the stool subtraction module. This detection improved significantly (p = 0.009) after automated colon cleansing on cathartic-free data to 86.4% true positive rate at 5.75 false positives/scan. Conclusions: An automated image-based colon cleansing algorithm designed to overcome the challenges of the noncathartic colon significantly improves the sensitivity of colon CAD by approximately 15%.

  11. 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.)

  12. CT colonography: comparison of a colon dissection display versus 3D endoluminal view for the detection of polyps

    International Nuclear Information System (INIS)

    Juchems, Markus S.; Pauls, Sandra; Brambs, Hans-Juergen; Aschoff, Andrik J.; Fleiter, Thorsten R.; Schmidt, Stefan A.

    2006-01-01

    The purpose of this study was to compare sensitivity, specificity, and postprocessing time of a colon dissection approach to regular 3D-endoluminal workup of computed tomography (CT) colonography for the detection of polypoid lesions. Twenty-one patients who had received conventional colonoscopy after CT colonography were selected; 18 patients had either colon polyps or colon cancer and three had no findings. CT colonography was performed using a 4-channel multi-detector-row (MDR) CT in ten cases and a 16-channel MDR-CT in 11 cases. A blinded reader retrospectively evaluated all colonographies using both viewing methods in a randomized order. Thirty-seven polyps were identified by optical colonoscopy. An overall per-lesion sensitivity of 47.1% for lesions smaller than 5 mm, 56.3% for lesions between 5 mm and 10 mm, and 75.0% for lesion larger than 10 mm was calculated using the colon dissection approach. This compared to an overall per-lesion sensitivity of 35.3% ( 10 mm) using the endoluminal view. The average time consumption for CT colonography evaluation with the colon dissection software was 10 min versus 38 min using the endoluminal view. A colon dissection approach may provide a significant time advantage for evaluation of CT colonography while obtaining a high sensitivity. It is especially superior in the detection of lesions smaller than 5 mm. (orig.)

  13. 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.

  14. Radiation protection in newer medical imaging techniques: CT colonography

    International Nuclear Information System (INIS)

    2008-01-01

    Multislice/detector computed tomography (CT) scanning, applied to visualization of the colon in CT colonography (CTC), also known as virtual colonoscopy (VC), is a relatively new application of CT introduced in recent years. The possibility of its application in population screening techniques raises a number of questions. Effort is required to ensure that the benefit of this new practice will not pose an undue level of detriment to the individual in multiple examinations. For practitioners and regulators, it is evident that innovation has been driven by both the imaging industry and by an ever increasing array of new applications generated and validated in the clinical environment. Regulation, industrial standardization, safety procedures and advice on best practice lag (inevitably) behind the industrial and clinical innovations being achieved. This series of Safety Reports (Nos 58, 60 and 61) is designed to help fill this growing vacuum, by bringing up to date and timely advice to bear on the problems involved. Under its statutory responsibility to establish standards for the protection of people against exposure to ionizing radiation and to provide for worldwide application of these standards, the IAEA has developed the Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS). The BSS was issued by the IAEA and co-sponsored by the Food and Agriculture Organization of the United Nations (FAO), the International Labour Organisation (ILO), the OECD Nuclear Energy Agency (OECD/NEA), the Pan American Health Organization (PAHO) and the World Health Organization (WHO), and requires radiation protection of patients undergoing medical exposures through justification of the procedures involved and through optimization. The IAEA programme on radiation protection of patients encourages the reduction of patient doses without losing diagnostic benefits. To facilitate this

  15. 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.

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

    Science.gov (United States)

    2012-06-21

    including cancers of the breast (68%) and cervix (82%) [18]. The comparatively low rate of compliance with national programmatic screening recommendations...Atlantic GI Consultants and Colon Health Center of Delaware, Newark, DE Abstract 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

  17. CT colonography: colonic distention improved by dual positioning but not intravenous glucagon

    International Nuclear Information System (INIS)

    Morrin, Martina M.; Keogan, Mary T.; Kruskal, Jonathan B.; Yam, Chun-Shan; Raptopoulos, Vassilios; Farrell, Richard J.

    2002-01-01

    The aim of this study was to determine whether intravenous (IV) glucagon and dual positioning administered prior to CT colonography enhances colonic distention. We assessed the effect of dual positioning and IV glucagon on colonic distention in 96 patients who underwent CT colonography examinations. The CT colonography was performed in both supine and prone positions. Seventy-four patients received glucagon (1 mg i.v.) immediately prior to CT scanning and 22 patients did not. The bowel was divided into ten segments and colonic distention was scored by two radiologists in the supine, prone, and combined supine/prone positions using a five-point scale: 1=collapsed; 2=poorly visualized; ≥3=adequate distention; 4=entire segment visualized and well distended; 5=excellent distention. A combined segmental and overall supine/prone distention score was calculated based on the sum of the mean score for each position. There was no significant difference in the degree of colonic distention between patients who received glucagon and those who did not [supine/prone distention score (mean±SE): 3.63±0.2 vs 3.85±0.2; p=n.s.]. The degree of colonic distention was greater in the prone position in both the glucagon (3.87±0.2 vs 3.38±0.2; p<0.05) and non-glucagon groups (4.01±0.2 vs 3.69±0.2; p=N.S.) particularly in the proximal colon. There was almost perfect agreement between both radiologists in their scoring of colonic distention on a per-patient basis (k=0.9; p<0.001). Of 1480 bowel segments, 1261 (85.2%) were adequately distended in the glucagon group compared with 370 of 440 bowel segments (84%) in the non-glucagon group (p=n.s.) Colonic distention at CT colonography is improved by dual positioning but not by the administration of intravenous glucagon. While our results suggest that other smooth muscle relaxants, including butyl scopolamine, may only have a limited role in improving colonic distention in CT colonography, further studies are required. (orig.)

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

    NARCIS (Netherlands)

    Liedenbaum, M.H.; de Vries, A.H.; Gouw, C.I.B.F.; van Rijn, A.F.; Bipat, S.; Dekker, E.; Stoker, J.

    2010-01-01

    PURPOSE: 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. MATERIALS AND METHODS: One hundred consecutive patients underwent CT colonography and colonoscopy with segmental

  19. 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.

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

    International Nuclear Information System (INIS)

    Boellaard, Thierry N.; Haan, Margriet C. de; Venema, Henk W.; Stoker, Jaap

    2013-01-01

    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

  1. CT colonography: Diagnostic role of contrast enhancement of benign polyps and colorectal carcinoma

    International Nuclear Information System (INIS)

    Stoinova, V.; Nedevska, M.

    2006-01-01

    Full text: The aim of this study was to compare pre- and postcontrast CT attenuation values of benign colorectal polyps and carcinoma lesions detected by CT colonography, and to investigate whether contrast enhancement of these lesions can be potentially used for differentiation from residual fluid and feces. We retrospectively reviewed CT colonographic dataset of 120 patients. 35 benign polyps and 22 colorectal carcinomas were included in our study. All lesions were confirmed by colonoscopic biopsy or surgery. The difference in attenuation value between precontrast and postcontrast studies of polyps was statistically significant; the same was true for colorectal cancers. In the precontrast phase no statistically significant difference was observed between stool, polyps and cancers. The mean attenuation value of solid fecal residuals was 37 HU before and after contrast enhancement. Residual fluid do not take up contrast and the density does not change in the contrast-enhanced phase. The difference between postcontrast density of polyps and cancers with respect to density of stools and residual fluid was significant. The use of contrast medium could be helpful in CT colonography for discriminating polypoid benign lesions and colorectal cancer from fecal and fluid residuals

  2. CT colonography training for radiographers - a formal evaluation

    International Nuclear Information System (INIS)

    Haycock, A.; Burling, D.; Wylie, P.; Muckian, J.; Ilangovan, R.; Thomas-Gibson, S.

    2010-01-01

    Aims: To evaluate the efficacy of a new intensive 'hands-on' course designed to train small teams of radiographers in computed tomography colonography (CTC) technique and initial interpretation for patient triage. Materials and methods: The course comprised small-group lectures, active participation in the daily CTC service with practical technique and image interpretation training by experienced radiologists and radiographers. Evaluation was by assessment of knowledge using randomized sets of multiple choice questions (MCQ; pre/post-course), practical technique using checklists and expert global scores, and interpretation performance outcomes using randomized pre/post-course test datasets (five validated CTC examinations each). Paired t-tests were used to investigate change in performance for MCQ score and interpretation accuracy. Results: Thirteen courses with 49 participants were evaluated over 2 years. Practical skills were high, with mean (SD) checklist scores of 14/15 (0.85) and global scores of 26/30 (2.3). MCQ scores increased significantly from a mean of 59% pre-course to 69% post-course, p 10 mm) detection rates also improved significantly from 49% to 60%, p = 0.002. Conclusion: Structured training in CTC can significantly improve knowledge and interpretation skills of radiographers, while assessing safe procedural performance. Implementation of similar programmes nationally may help reduce performance gaps between centres.

  3. 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.

  4. CT colonography: a survey of general practitioners' knowledge and interest.

    Science.gov (United States)

    Flor, Nicola; Laghi, Andrea; Peri, Mauro; Cornalba, Gianpaolo; Sardanelli, Francesco

    2016-01-01

    To verify the knowledge and interest of general practitioners on computed tomography colonography (CTC). In 2014, a Web-based questionnaire was proposed to all general practitioners of [Milan, Italy]. The questionnaire consisted of ten questions concerning general practitioners' knowledge about CTC, including application of guidelines in clinical scenarios and diagnostic performance. Out of 1,053 general practitioners, 231 (22%), 155 men and 76 women (mean age 58 years), completed the survey. We found a significant difference between the age of responders and that of non-responders (p = 0.0033). Of the 231 responders, 84% were aware of the possibility of using CTC as a method for examining the colon-rectum. However, only 57% were aware about low X-ray exposure delivered by CTC and about the possibility of using a reduced cleansing protocol. Only 48% were aware that CTC accuracy in diagnosing 10-mm or larger polyps and colorectal cancers was similar to that of conventional colonoscopy, while 62% were informed about CTC advantages in comparison with double-contrast barium enema; 59% thought that CTC had a potential role as a screening test; 85-86% suggested CTC in the case of refused or incomplete conventional colonoscopy; 79% suggested immediate conventional colonoscopy in the case of at least one 10-mm polyp. About 54% usually prescribe one CTC every 4-6 months, while 36% never have, 3% one CTC per month, and 7% one every 2-3 months. Ninety-four per cent declared that they were willing to attend a course on CTC. General practitioners have limited knowledge concerning CTC. Radiological societies should fill this gap offering dedicated educational initiatives.

  5. Low-Fiber Diet in Limited Bowel Preparation for CT Colonography: Influence on Image Quality and Patient Acceptance

    NARCIS (Netherlands)

    Liedenbaum, Marjolein H.; Denters, Maaike J.; de Vries, Ayso H.; van Ravesteijn, Vincent F.; Bipat, Shandra; Vos, Frans M.; Dekker, Evelien; Stoker, Jaap

    2010-01-01

    OBJECTIVE. The purpose of this study was to determine whether a low-fiber diet is necessary for optimal tagging-only bowel preparation for CT colonography. SUBJECTS AND METHODS. Fifty consecutively enrolled patients received an iodine bowel preparation: 25 patients used a low-fiber diet and 25 used

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

    NARCIS (Netherlands)

    Tutein Nolthenius, Charlotte J.; Boellaard, Thierry N.; de Haan, Margriet C.; Nio, C. Yung; Thomeer, Maarten G. J.; Bipat, Shandra; Montauban van Swijndregt, Alexander D.; Essink-Bot, Marie-Louise; Kuipers, Ernst J.; Dekker, Evelien; Stoker, Jaap

    2016-01-01

    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

  7. CT colonography: Project of High National Interest No. 2005062137 of the Italian Ministry of Education, University and Research (MIUR).

    Science.gov (United States)

    Neri, E; Laghi, A; Regge, D; Sacco, P; Gallo, T; Turini, F; Talini, E; Ferrari, R; Mellaro, M; Rengo, M; Marchi, S; Caramella, D; Bartolozzi, C

    2008-12-01

    The aim of this paper is to describe the Web site of the Italian Project on CT Colonography (Research Project of High National Interest, PRIN No. 2005062137) and present the prototype of the online database. The Web site was created with Microsoft Office Publisher 2003 software, which allows the realisation of multiple Web pages linked through a main menu located on the home page. The Web site contains a database of computed tomography (CT) colonography studies in the Digital Imaging and Communications in Medicine (DICOM) standard, all acquired with multidetector-row CT according to the parameters defined by the European Society of Abdominal and Gastrointestinal Radiology (ESGAR). The cases present different bowel-cleansing and tagging methods, and each case has been anonymised and classified according to the Colonography Reporting and Data System (C-RADS). The Web site is available at http address www.ctcolonography.org and is composed of eight pages. Download times for a 294-Mbyte file were 33 min from a residential ADSL (6 Mbit/s) network, 200 s from a local university network (100 Mbit/s) and 2 h and 50 min from a remote academic site in the USA. The Web site received 256 accesses in the 22 days since it went online. The Web site is an immediate and up-to-date tool for publicising the activity of the research project and a valuable learning resource for CT colonography.

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

    NARCIS (Netherlands)

    Liedenbaum, Marjolein Henrieke; van Rijn, Anne Floortje; de Vries, Ayso H.; Dekker, Helena M.; Thomeer, Maarten; van Marrewijk, Corine J.; Hol, Lieke; Dijkgraaf, Marcel G.; Fockens, Paul; Bossuyt, Patrick M.; Dekker, Evelien; Stoker, Jaap

    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

  9. 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.

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

    NARCIS (Netherlands)

    de Haan, Margriet C.; Boellaard, Thierry N.; Bossuyt, Patrick M.; Stoker, Jaap

    2012-01-01

    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

  11. CT-colonography in population-based colorectal cancer screening

    NARCIS (Netherlands)

    de Haan, M.C.

    2012-01-01

    In een proefbevolkingsonderzoek naar dikkedarmkanker vergeleek Margriet de Haan coloscopie (onderzoek met een dunne flexibele slang met camera om de darm van binnenuit te bekijken) met CT-colografie (onderzoek waarbij de darmen worden onderzocht zonder slang) wat betreft opkomst, opbrengst,

  12. Effect of computer-aided detection as a second reader in multidetector-row CT colonography

    International Nuclear Information System (INIS)

    Mang, Thomas; Peloschek, Philipp; Plank, Christina; Maier, Andrea; Weber, Michael; Herold, Christian; Schima, Wolfgang; Graser, Anno; Bogoni, Luca

    2007-01-01

    Our purpose was to assess the effect of computer-aided detection (CAD) on lesion detection as a second reader in computed tomographic colonography, and to compare the influence of CAD on the performance of readers with different levels of expertise. Fifty-two CT colonography patient data-sets (37 patients: 55 endoscopically confirmed polyps ≥0.5 cm, seven cancers; 15 patients: no abnormalities) were retrospectively reviewed by four radiologists (two expert, two nonexpert). After primary data evaluation, a second reading augmented with findings of CAD (polyp-enhanced view, Siemens) was performed. Sensitivities and reading time were calculated for each reader without CAD and supported by CAD findings. The sensitivity of expert readers was 91% each, and of nonexpert readers, 76% and 75%, respectively, for polyp detection. CAD increased the sensitivity of expert readers to 96% (P = 0.25) and 93% (P = 1), and that of nonexpert readers to 91% (P = 0.008) and 95% (P = 0.001), respectively. All four readers diagnosed 100% of cancers, but CAD alone only 43%. CAD increased reading time by 2.1 min (mean). CAD as a second reader significantly improves sensitivity for polyp detection in a high disease prevalence population for nonexpert readers. CAD causes a modest increase in reading time. CAD is of limited value in the detection of cancer. (orig.)

  13. Evaluation of colonic lesions and pitfalls in CT colonography: A systematic approach based on morphology, attenuation and mobility

    International Nuclear Information System (INIS)

    Mang, Thomas; Gryspeerdt, Stefaan; Schima, Wolfgang; Lefere, Philippe

    2013-01-01

    Computed tomographic colonography is a reliable technique for the detection and classification of neoplastic and non-neoplastic lesions of the colon. It is based on a thin-section CT dataset of the cleansed and air-distended colon, acquired in prone and supine position. Two-dimensional and 3D projections are used in combination for image interpretation. The evaluation of CT colonography datasets is based on two steps, lesion perception to detect a polyp candidate and image interpretation to correctly characterize colonic filling defects. A thorough knowledge of the morphologic and attenuation characteristics of common colonic lesions and artifacts facilitates characterization of the findings. The purpose of this review article is to give an overview of the key CT colonographic imaging criteria to correctly characterize common colorectal lesions and to identify typical pitfalls and pseudolesions

  14. 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

    OBJECTIVE: To assess the performance of radiographers in CT colonography (CTC) after a tele-training programme, supervised by 2 experienced radiologists. MATERIALS AND METHODS: Five radiographers underwent training in CTC using a tele-training programme mainly based on the interpretation of 75...... training cases performed in the novice department. To evaluate the educational performance, each radiographer was tested on 20 test cases with 27 lesions >6mm (12: 6-9mm; 15: >10mm). Sensitivity, specificity and PPV for polyps ≥6mm and ≥10mm were calculated with point estimates and 95% confidence interval...... (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...

  15. 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.

  16. The Association of Anisakiasis in the Ascending Colon with Sigmoid Colon Cancer: CT Colonography Findings

    International Nuclear Information System (INIS)

    Yoo, Hye Jin; Kim, Se Hyung; Lee, Jeong Min; Kim, Min A; Han, Joon Koo; Choi, Byung Ihn

    2008-01-01

    The association of anisakiasis of the colon with colon cancer is rare and difficult to diagnose. Only one case of this type has been reported to date. In this study, we report a case of synchronous colon cancer and colonic anisakiasis. A 50- year-old woman was admitted for abdominal pain, and a volume-rendered surface- shaded image of CT colonography (CTC) revealed a concentric narrowing in the sigmoid colon and a segmental fold thickening in the ascending colon. A total colectomy was performed and the diagnosis of synchronous sigmoid colon cancer and anisakiasis of the ascending colon was confirmed. This case is the first reported visualization of synchronous colon cancer and colonic anisakiasis on a CTC

  17. A comparison of primary two- and three-dimensional methods to review CT colonography

    International Nuclear Information System (INIS)

    Gelder, Rogier E. van; Florie, Jasper; Nio, C. Yung; Jager, Steven W. de; Lameris, Johan S.; Stoker, Jaap; Jensch, Sebastiaan; Vos, Frans M.; Venema, Henk W.; Bartelsman, Joep F.; Reitsma, Johannes B.; Bossuyt, Patrick M.M.

    2007-01-01

    The aim of our study was to compare primary three-dimensional (3D) and primary two-dimensional (2D) review methods for CT colonography with regard to polyp detection and perceptive errors. CT colonography studies of 77 patients were read twice by three reviewers, first with a primary 3D method and then with a primary 2D method. Mean numbers of true and false positives, patient sensitivity and specificity and perceptive errors were calculated with colonoscopy as a reference standard. A perceptive error was made if a polyp was not detected by all reviewers. Mean sensitivity for large (≥10 mm) polyps for primary 3D and 2D review was 81% (14.7/18) and 70%(12.7/18), respectively (p-values ≥0.25). Mean numbers of large false positives for primary 3D and 2D were 8.3 and 5.3, respectively. With primary 3D and 2D review 1 and 6 perceptive errors, respectively, were made in 18 large polyps (p = 0.06). For medium-sized (6-9 mm) polyps these values were for primary 3D and 2D, respectively: mean sensitivity: 67%(11.3/17) and 61%(10.3/17; p-values≥ 0.45), number of false positives: 33.3 and 15.6, and perceptive errors: 4 and 6 (p = 0.53). No significant differences were found in the detection of large and medium-sized polyps between primary 3D and 2D review. (orig.)

  18. 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.)

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  20. Colonic polyp detection in CT colonography with fuzzy rule based 3D template matching.

    Science.gov (United States)

    Kilic, Niyazi; Ucan, Osman N; Osman, Onur

    2009-02-01

    In this paper, we introduced a computer aided detection (CAD) system to facilitate colonic polyp detection in computer tomography (CT) data using cellular neural network, genetic algorithm and three dimensional (3D) template matching with fuzzy rule based tresholding. The CAD system extracts colon region from CT images using cellular neural network (CNN) having A, B and I templates that are optimized by genetic algorithm in order to improve the segmentation performance. Then, the system performs a 3D template matching within four layers with three different cell of 8 x 8, 12 x 12 and 20 x 20 to detect polyps. The CAD system is evaluated with 1043 CT colonography images from 16 patients containing 15 marked polyps. All colon regions are segmented properly. The overall sensitivity of proposed CAD system is 100% with the level of 0.53 false positives (FPs) per slice and 11.75 FPs per patient for the 8 x 8 cell template. For the 12 x 12 cell templates, detection sensitivity is 100% at 0.494 FPs per slice and 8.75 FPs per patient and for the 20 x 20 cell templates, detection sensitivity is 86.66% with the level of 0.452 FPs per slice and 6.25 FPs per patient.

  1. CT colonography without cathartic preparation: positive predictive value and patient experience in clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Zueco Zueco, Carmen; Sobrido Sampedro, Carolina; Corroto, Juan D.; Rodriguez Fernandez, Paula; Fontanillo Fontanillo, Manuela [Complexo Hospitalario Universitario de Vigo - CHUVI, Vigo, Pontevedra (Spain)

    2012-06-15

    To determine the positive predictive value (PPV) for polyps {>=}6 mm detected at CT colonography (CTC) performed without cathartic preparation, with low-dose iodine faecal tagging regimen and to evaluate patient experience. 1920 average-risk patients underwent CTC without cathartic preparation. Faecal tagging was performed by diatrizoate meglumine and diatrizoate sodium at a total dose of 60 ml (22.2 g of iodine).The standard interpretation method was primary 3D with 2D problem solving. We calculated per-patient and per-polyp PPV in relation to size and morphology. All colonic segments were evaluated for image quality (faecal tagging, amount of liquid and solid residual faeces and luminal distension). Patients completed a questionnaire before and after CTC to assess preparation and examination experience. Per-polyp PPV for detected lesions of {>=}6 mm, 6-9 mm, {>=}10 mm and {>=}30 mm were 94.3%, 93.1%, 94.7% and 98%, respectively. Per-polyp PPV, according to lesion morphology, was 94.6%, 97.3% and 85.1% for sessile, pedunculated and flat polyps, respectively. Per-patient PPV was 92.8%. Preparation without frank cathartics was reported to cause minimal discomfort by 78.9% of patients. CTC without cathartic preparation and low-dose iodine faecal tagging may yield high PPVs for lesions {>=}6 mm and is well accepted by patients. circle Computed tomographic colonography (CTC) without cathartic preparation is well accepted by patients circle Cathartic-free faecal tagging CTC yields high positive predictive values circle CTC without cathartic preparation could improve uptake of colorectal cancer screening. (orig.)

  2. Electronic cleansing for CT colonography using spectral-driven iterative reconstruction

    Science.gov (United States)

    Nasirudin, Radin A.; Näppi, Janne J.; Hironaka, Toru; Tachibana, Rie; Yoshida, Hiroyuki

    2017-03-01

    Dual-energy computed tomography is used increasingly in CT colonography (CTC). The combination of computer-aided detection (CADe) and dual-energy CTC (DE-CTC) has high clinical value, because it can detect clinically significant colonic lesions automatically at higher accuracy than does conventional single-energy CTC. While CADe has demonstrated its ability to detect small polyps, its performance is highly dependent on several factors, including the quality of CTC images and electronic cleansing (EC) of the images. The presence of artifacts such as beam hardening and image noise in ultra-low-dose CTC can produce incorrectly cleansed colon images that severely degrade the detection performance of CTC for small polyps. Also, CADe methods are very dependent on the quality of input images and the information about different tissues in the colon. In this work, we developed a novel method to calculate EC images using spectral information from DE-CTC data. First, the ultra-low dose dual-energy projection data obtained from a CT scanner are decomposed into two materials, soft tissue and the orally administered fecal-tagging contrast agent, to detect the location and intensity of the contrast agent. Next, the images are iteratively reconstructed while gradually removing the presence of tagged materials from the images. Our preliminary qualitative results show that the method can cleanse the contrast agent and tagged materials correctly from DE-CTC images without affecting the appearance of surrounding tissue.

  3. DMLLE: a large-scale dimensionality reduction method for detection of polyps in CT colonography

    Science.gov (United States)

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

    2008-03-01

    Computer-aided diagnosis systems have been shown to be feasible for polyp detection on computed tomography (CT) scans. After 3-D image segmentation and feature extraction, the dataset of colonic polyp candidates has large-scale and high dimension characteristics. In this paper, we propose a large-scale dimensionality reduction method based on Diffusion Map and Locally Linear Embedding for detection of polyps in CT colonography. By selecting partial data as landmarks, we first map the landmarks into a low dimensional embedding space using Diffusion Map. Then by using Locally Linear Embedding algorithm, non-landmark samples are embedded into the same low dimensional space according to their nearest landmark samples. The local geometry of samples is preserved in both the original space and the embedding space. We applied the proposed method called DMLLE to a colonic polyp dataset which contains 58336 candidates (including 85 6-9mm true polyps) with 155 features. Visual inspection shows that true polyps with similar shapes are mapped to close vicinity in the low dimensional space. FROC analysis shows that SVM with DMLLE achieves higher sensitivity with lower false positives per patient than that of SVM using all features. At the false positives of 8 per patient, SVM with DMLLE improves the average sensitivity from 64% to 75% for polyps whose sizes are in the range from 6 mm to 9 mm (p < 0.05). This higher sensitivity is comparable to unaided readings by trained radiologists.

  4. 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.

  5. 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.)

  6. Effect of CADe on radiologists' performance in detection of "difficult" polyps in CT colonography

    Science.gov (United States)

    Suzuki, Kenji; Hori, Masatoshi; Iinuma, Gen; Dachman, Abraham H.

    2013-03-01

    To investigate the actual usefulness of computer-aided detection (CADe) of polyps as a second reader, we conducted a free-response observer performance study with radiologists in the detection of "difficult" polyps in CT colonography (CTC) from a multicenter clinical trial. The "difficult" polyps were defined as the ones that had been "missed" by radiologists in the clinical trial or rated "difficult" in our retrospective review. Our advanced CADe scheme utilizing massive-training artificial neural networks (MTANNs) technology was sensitive and specific to the "difficult" polyps. Four board-certified abdominal radiologists participated in this observer study. They were instructed, first without and then with our CADe, to indicate the location of polyps and their confidence level regarding the presence of polyps. Our database contains 20 patients with 23 polyps including 14 false-negative (FN) and 7 "difficult" polyps and 10 negative patients. With CADe, the average by-polyp sensitivity of radiologists was improved from 53 to 63% at a statistically significant level (P=0.037). Thus, our CADe scheme utilizing the MTANN technology improved the diagnostic performance of radiologists, including expert readers, in the detection of "difficult" polyps in CTC.

  7. Computer-aided detection of polyps in CT colonography by means of AdaBoost

    Science.gov (United States)

    Xu, Jian-Wu; Suzuki, Kenji

    2012-03-01

    Computer-aided detection (CADe) has been investigated for assisting radiologists in detecting polyps in CT colonography (CTC). One of the major challenges in current CADe of polyps in CTC is to improve the specificity without sacrificing the sensitivity. We have developed several CADe schemes based on a massive-training framework with different nonlinear regression models such as neural network regression, support vector regression, and Gaussian process regression. Individual CADe schemes based on different nonlinear regression models, however, achieved comparable results. In this paper, we propose to use the AdaBoost algorithm to combine different regression models in CADe schemes for improving the specificity without sacrificing the sensitivity. To test the performance of the proposed approach, we compared it with individual regression models in the distinction between polyps and various types of false positives (FPs). Our CTC database consisted of 246 CTC datasets obtained from 123 patients in the supine and prone positions. The testing set contained 93 patients including 19 polyps in seven patients and 86 negative patients with 474 FPs produced by an original CADe scheme. The AdaBoost algorithm combining multiple massive-training regression models achieved a performance that was higher than each individual regression model, yielding a 94.7% (18/19) bypolyp sensitivity at an FP rate of 2.0 (188/93) per patient in a leave-one-lesion-out cross validation test.

  8. Bowel preparation for CT-colonography: Comparison of two different cleansing protocols

    International Nuclear Information System (INIS)

    Juchems, Markus S.; Hoffmann, Martin H.K.; Schmidt, Stefan A.; Apostel, Anna; Brambs, Hans-Juergen; Aschoff, Andrik J.

    2006-01-01

    Objective: Comparison of cleansing effects and colonic distension observed with two polyethyleneglycol-solution (PEG) containing bowel preparation techniques prior to CT-colonography (CTC). Materials and methods: One hundred and three patients that received CTC in our institution were retrospectively evaluated. Fifty-one patients received preparation 1 (BP1; based on a GoLytely formulation + bisacodyl), 52 preparation 2 (BP2; based on a NuLytely formulation + bisacodyl). On multi-planar-reformatted (MPR) images, fluid residuals and colon distension were assessed in five colonic segments, from the ascending colon to the rectum. Results: On average, significantly (p < 0.001) lower fluid residuals were assesses when using BP2 regardless of the patient position. In prone position, a significantly lower fluid level was observed in the sigmoid using bowel preparation 2. The average maximum diameter measured for the whole colon was 5.2 ± 0.6 cm in prone position and 4.8 ± 0.6 cm in the supine position in BP1 (p < 0.01). In BP2 the average maximum diameter measured for the whole colon was 5.3 ± 0.6 cm in prone position and 4.7 ± 0.5 cm in supine position, respectively (p < 0.001). Conclusion: Overall, lower fluid residuals were scored using BP2. In both preparation groups we achieved better colonic distension in prone position. We were not able to distend the sigmoid better when insufflating air during patient repositioning

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

    International Nuclear Information System (INIS)

    De Cecco, Carlo Nicola; Ciolina, Maria; Rengo, Marco; Bellini, Davide; Muscogiuri, Giuseppe; Iafrate, Franco; Laghi, Andrea; Annibale, Bruno; Maruotti, Antonello; Saba, Luca

    2016-01-01

    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.)

  10. Low-dose CT colonography in children: initial experience, technical feasibility and utility

    International Nuclear Information System (INIS)

    Anupindi, Sudha; Perumpillichira, James; Zalis, Michael E.; Jaramillo, Diego; Israel, Esther J.

    2005-01-01

    CT colonography (CTC) is utilized as a diagnostic tool in the detection of colon polyps and early colorectal cancer in adults. Large studies in the literature, although focused on adult populations, have shown CTC to be a safe, accurate, non-invasive technique. We evaluated the technical feasibility of CTC in children using a low-dose technique. From November 2001 to April 2004 we evaluated eight patients (3-17 years) with non-contrast CTC. Seven of the patients had CTC, followed by standard colonoscopy (SC) the same day; in one patient, CTC followed a failed SC. CTC results were compared to results of SC. The estimated effective dose from each CTC was calculated and compared to that of standard barium enema. CTC results were consistent with those of SC. Sensitivity for polyps 5-10 mm was 100%, and sensitivity for polyps 10 mm and larger was 66.7%. The estimated mean effective dose was 2.17 mSv for CTC, compared to the 5-6 mSv for a standard air-contrast barium enema in a small child. Our initial experience shows CTC in children is well-tolerated, safe, and useful. The procedure can be performed successfully with a low radiation dose, and preliminary results compare well with SC. (orig.)

  11. 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.)

  12. CT colonography: computer-aided detection of morphologically flat T1 colonic carcinoma

    International Nuclear Information System (INIS)

    Taylor, Stuart A.; Iinuma, Gen; Saito, Yutaka; Zhang, Jie; Halligan, Steve

    2008-01-01

    The purpose was to evaluate the ability of computer-aided detection (CAD) software to detect morphologically flat early colonic carcinoma using CT colonography (CTC). Twenty-four stage T1 colonic carcinomas endoscopically classified as flat (width over twice height) were accrued from patients undergoing staging CTC. Tumor location was annotated by three experienced radiologists in consensus aided by the endosocpic report. CAD software was then applied at three settings of sphericity (0, 0.75, and 1). Computer prompts were categorized as either true positive (overlapping tumour boundary) or false positive. True positives were subclassified as focal or non focal. The 24 cancers were endoscopically classified as type IIa (n=11) and type IIa+IIc (n=13). Mean size (range) was 27 mm (7-70 mm). CAD detected 20 (83.3%), 17 (70.8%), and 13 (54.1%) of the 24 cancers at filter settings of 0, 0.75, and 1, respectively with 3, 4, and 8 missed cancers of type IIa, respectively. The mean total number of false-positive CAD marks per patient at each filter setting was 36.5, 21.1, and 9.5, respectively, excluding polyps. At all settings, >96.1% of CAD true positives were classified as focal. CAD may be effective for the detection of morphologically flat cancer, although minimally raised laterally spreading tumors remain problematic. (orig.)

  13. 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.

  14. Comparative evaluation of the fecal-tagging quality in CT colonography: barium vs. iodinated oral contrast agent.

    Science.gov (United States)

    Nagata, Koichi; Singh, Anand Kumar; Sangwaiya, Minal Jagtiani; Näppi, Janne; Zalis, Michael E; Cai, Wenli; Yoshida, Hiroyuki

    2009-11-01

    The purpose of this evaluation was to compare the tagging quality of a barium-based regimen with that of iodine-based regimens for computed tomographic (CT) colonography. Tagging quality was assessed retrospectively in three different types of fecal-tagging CT colonographic cases: 24 barium-based cases, 22 nonionic iodine-based cases, and 24 ionic iodine-based cases. For the purpose of evaluation, the large intestine was divided into six segments, and the tagging homogeneity of a total of 420 segments (70 patients) was graded by three blinded readers from 0 (heterogeneous) to 4 (homogeneous). For barium-based cases, the average score for the three readers was 2.4, whereas it was 3.4 for nonionic iodine and 3.6 for ionic iodine. The percentages of segments that were assigned scores of 4 (excellent tagging [100%]) were 11.6%, 61.9%, and 72.9% for the barium-based, nonionic iodine-based, and ionic iodine-based regimens, respectively. The homogeneity scores of iodine-based fecal-tagging regimens were significantly higher than those of the barium-based fecal-tagging regimen (P barium-based regimen (P barium-based fecal-tagging regimen. Iodine-based fecal-tagging regimens can provide an appropriate method for use in nonlaxative or minimum-laxative CT colonography.

  15. 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.

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

    Science.gov (United States)

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

    2017-12-01

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

  17. Deep ensemble learning of virtual endoluminal views for polyp detection in CT colonography

    Science.gov (United States)

    Umehara, Kensuke; Näppi, Janne J.; Hironaka, Toru; Regge, Daniele; Ishida, Takayuki; Yoshida, Hiroyuki

    2017-03-01

    Robust training of a deep convolutional neural network (DCNN) requires a very large number of annotated datasets that are currently not available in CT colonography (CTC). We previously demonstrated that deep transfer learning provides an effective approach for robust application of a DCNN in CTC. However, at high detection accuracy, the differentiation of small polyps from non-polyps was still challenging. In this study, we developed and evaluated a deep ensemble learning (DEL) scheme for reviewing of virtual endoluminal images to improve the performance of computer-aided detection (CADe) of polyps in CTC. Nine different types of image renderings were generated from virtual endoluminal images of polyp candidates detected by a conventional CADe system. Eleven DCNNs that represented three types of publically available pre-trained DCNN models were re-trained by transfer learning to identify polyps from the virtual endoluminal images. A DEL scheme that determines the final detected polyps by a review of the nine types of VE images was developed by combining the DCNNs using a random forest classifier as a meta-classifier. For evaluation, we sampled 154 CTC cases from a large CTC screening trial and divided the cases randomly into a training dataset and a test dataset. At 3.9 falsepositive (FP) detections per patient on average, the detection sensitivities of the conventional CADe system, the highestperforming single DCNN, and the DEL scheme were 81.3%, 90.7%, and 93.5%, respectively, for polyps ≥6 mm in size. For small polyps, the DEL scheme reduced the number of false positives by up to 83% over that of using a single DCNN alone. These preliminary results indicate that the DEL scheme provides an effective approach for improving the polyp detection performance of CADe in CTC, especially for small polyps.

  18. Bowel preparation in CT colonography. Is diet restriction necessary? A randomised trial (DIETSAN)

    International Nuclear Information System (INIS)

    Bellini, Davide; De Santis, Domenico; Caruso, Damiano; Rengo, Marco; Biondi, Tommaso; Laghi, Andrea; Ferrari, Riccardo

    2018-01-01

    To investigate whether diet restriction affects quality of colon cleansing and patient tolerance during reduced bowel preparation for CT colonography (CTC). Asymptomatic and symptomatic patients were enrolled in this pragmatic, single-centre, randomised trial. All patients were randomly assigned (1:1 ratio, blocks of ten) to receive a reduced bowel preparation and faecal tagging with (Diet-Restriction-Group [DR]) or without (No-Diet-Restriction-Group [NDR]) dietary restriction. Five readers performed a blinded subjective image analysis, by means of 4-point Likert-scales from 0 (highest score) to 3 (worst score). Endpoints were the quality of large bowel cleansing and tolerance to the assigned bowel preparation regimen. The trial is registered at ClinicalTrial.gov (URomLSDBAL1). Ninety-five patients were randomly allocated to treatments (48 in NDR-group, 47 in DR-group). Both groups resulted in optimal colon cleansing. The mean residual stool (0.22, 95%CI 0.00-0.44) and fluid burden (0.39, 95%CI 0.25-0.53) scores for patients in DR-group were similar to those in patients in NDR-group (0.25, 95%CI 0.03-0.47 [p = 0.82] and 0.49, 95%CI 0.30-0.67 [p = 0.38], respectively). Tolerance was significantly better in NDR-group. A reduced bowel preparation in association with faecal tagging and without any dietary restriction demonstrated optimal colon cleansing effectiveness for CTC, providing better patient compliance compared with dietary restriction. (orig.)

  19. Computer-aided diagnosis in contrast-enhanced CT colonography: an approach based on contrast

    International Nuclear Information System (INIS)

    Luboldt, Wolfgang; Kroll, Manuela; Vogl, Thomas J.; Mann, Carolin; Vonthein, Reinhard; Stueker, Dietmar; Luz, Oliver; Claussen, Claus D.; Tryon, Cathy L.

    2002-01-01

    Automation in colorectal mass detection is achieved as soon as the voxels representing colorectal masses can be automatically segmented. We tested the Hounsfield (HU) value in intensely contrast enhanced high-resolution CT colonography for automated segmentation of colorectal masses in 18 patients with 35 polyps (28<10 mm, 7 ≥10 mm) and 7 carcinomas. Mean HU values of the colonic wall and masses were determined to deduce a gradient threshold for a segmentation process, which encodes the voxels bordering the colonic lumen with a colour ranging in intensity from 0 to 100% according to the selected gradient threshold range in the volume rendering. The results of the automated segmentation process were superimposed on a virtual double contrast and endoscopic display and validated through correlation with morphology. Mean HU values and their standard deviations for the colonic wall, polyps <10 mm, polyps ≥10 mm and carcinomas were 63±24, 154±38, 116±41 and 108±29 HU, respectively. A gradient threshold ranging from 90 to 160 HU resulted in colour pools in 6 of 7 of polyps ≥10 mm, and 6 of 7 carcinomas that were significant enough to prospectively guide the reader's attention to these masses. Due to the superposition of ''false-positive'' voxels in the projection view, the virtual endoscopic perspective was superior to the virtual double contrast display for controlling the segmentation results. The HU value is promising for automated segmentation of colorectal masses but needs to be combined with morphological parameters to render automated colorectal mass detection more accurate. Further refinements of the method with subsequent analysis of its accuracy, as well as analogue studies with contrast-enhanced MRI, appear warranted. More information at http://www.multiorganscreening.org (orig.)

  20. Reducing the radiation dose for CT colonography using adaptive statistical iterative reconstruction: A pilot study.

    Science.gov (United States)

    Flicek, Kristina T; Hara, Amy K; Silva, Alvin C; Wu, Qing; Peter, Mary B; Johnson, C Daniel

    2010-07-01

    The purpose of our study was to evaluate the feasibility of preserving image quality during CT colonography (CTC) using a reduced radiation dose with adaptive statistical iterative reconstruction (ASIR). A proven colon phantom was imaged at standard dose settings (50 mAs) and at reduced doses (10-40 mAs) using six different ASIR levels (0-100%). We assessed 2D and 3D image quality and noise to determine the optimal dose and ASIR setting. Eighteen patients were then scanned with a standard CTC dose (50 mAs) in the supine position and at a reduced dose of 25 mAs with 40% ASIR in the prone position. Three radiologists blinded to the scanning techniques assessed 2D and 3D image quality and noise at three different colon locations. A score difference of > or = 1 was considered clinically important. Actual noise measures were compared between the standard-dose and low-dose acquisitions. The phantom study showed image noise reduction that correlated with a higher percentage of ASIR. In patients, no significant image quality differences were identified between standard- and low-dose images using 40% ASIR. Overall image quality was reduced for both image sets as body mass index increased. Measured image noise was less with the low-dose technique using ASIR. The results of this pilot study show that the radiation dose during CTC can be reduced 50% below currently accepted low-dose techniques without significantly affecting image quality when ASIR is used. Further evaluation in a larger patient group is warranted.

  1. Computer-assisted polyp matching between optical colonoscopy and CT colonography: a phantom study

    Science.gov (United States)

    Roth, Holger R.; Hampshire, Thomas E.; Helbren, Emma; Hu, Mingxing; Vega, Roser; Halligan, Steve; Hawkes, David J.

    2014-03-01

    Potentially precancerous polyps detected with CT colonography (CTC) need to be removed subsequently, using an optical colonoscope (OC). Due to large colonic deformations induced by the colonoscope, even very experienced colonoscopists find it difficult to pinpoint the exact location of the colonoscope tip in relation to polyps reported on CTC. This can cause unduly prolonged OC examinations that are stressful for the patient, colonoscopist and supporting staff. We developed a method, based on monocular 3D reconstruction from OC images, that automatically matches polyps observed in OC with polyps reported on prior CTC. A matching cost is computed, using rigid point-based registration between surface point clouds extracted from both modalities. A 3D printed and painted phantom of a 25 cm long transverse colon segment was used to validate the method on two medium sized polyps. Results indicate that the matching cost is smaller at the correct corresponding polyp between OC and CTC: the value is 3.9 times higher at the incorrect polyp, comparing the correct match between polyps to the incorrect match. Furthermore, we evaluate the matching of the reconstructed polyp from OC with other colonic endoluminal surface structures such as haustral folds and show that there is a minimum at the correct polyp from CTC. Automated matching between polyps observed at OC and prior CTC would facilitate the biopsy or removal of true-positive pathology or exclusion of false-positive CTC findings, and would reduce colonoscopy false-negative (missed) polyps. Ultimately, such a method might reduce healthcare costs, patient inconvenience and discomfort.

  2. Bowel preparation in CT colonography. Is diet restriction necessary? A randomised trial (DIETSAN)

    Energy Technology Data Exchange (ETDEWEB)

    Bellini, Davide; De Santis, Domenico; Caruso, Damiano; Rengo, Marco; Biondi, Tommaso; Laghi, Andrea [Rome Univ. ' ' Sapienza' ' (Italy). Dept. of Radiological Sciences, Oncology and Pathology; I.C.O.T. Hospital, Latina (Italy); Ferrari, Riccardo [San Camillo Forlanini Hospital, Rome (Italy). Dept. of Emergency Radiology

    2018-01-15

    To investigate whether diet restriction affects quality of colon cleansing and patient tolerance during reduced bowel preparation for CT colonography (CTC). Asymptomatic and symptomatic patients were enrolled in this pragmatic, single-centre, randomised trial. All patients were randomly assigned (1:1 ratio, blocks of ten) to receive a reduced bowel preparation and faecal tagging with (Diet-Restriction-Group [DR]) or without (No-Diet-Restriction-Group [NDR]) dietary restriction. Five readers performed a blinded subjective image analysis, by means of 4-point Likert-scales from 0 (highest score) to 3 (worst score). Endpoints were the quality of large bowel cleansing and tolerance to the assigned bowel preparation regimen. The trial is registered at ClinicalTrial.gov (URomLSDBAL1). Ninety-five patients were randomly allocated to treatments (48 in NDR-group, 47 in DR-group). Both groups resulted in optimal colon cleansing. The mean residual stool (0.22, 95%CI 0.00-0.44) and fluid burden (0.39, 95%CI 0.25-0.53) scores for patients in DR-group were similar to those in patients in NDR-group (0.25, 95%CI 0.03-0.47 [p = 0.82] and 0.49, 95%CI 0.30-0.67 [p = 0.38], respectively). Tolerance was significantly better in NDR-group. A reduced bowel preparation in association with faecal tagging and without any dietary restriction demonstrated optimal colon cleansing effectiveness for CTC, providing better patient compliance compared with dietary restriction. (orig.)

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

    International Nuclear Information System (INIS)

    Liedenbaum, Marjolein H.; Vries, A.H. de; Bipat, S.; Stoker, J.; Gouw, C.I.B.F.; Rijn, A.F. van; Dekker, E.

    2010-01-01

    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.)

  4. CT colonography for preoperative examination of the proximal colon using a transanal drainage tube for acute malignant colonic obstruction

    International Nuclear Information System (INIS)

    Sasaki, Kazuaki; Hirano, Yuji; Oono, Keisuke; Sasaki, Kazunori; Someya, Tetsufumi; Harada, Keisuke; Ezoe, Eiri; Furuhata, Tomohisa; Hirata, Koichi

    2011-01-01

    The purpose of this study was to evaluate the feasibility of CT colonography for preoperative examination of the proximal colon using a transanal drainage tube in patients with acute colon obstruction caused by colorectal cancer. Ten patients who received initial treatment for acute malignant colon obstruction at our hospital between June 2004 and December 2008 were studied. In these patients, elective surgery was possible after transanal drainage tube insertion, and the colon on the oral side from the cancer lesion was examined using a drainage tube. Air was injected through the tube into the oral side of the colon, and CT colonography was assessed for the presence or absence of lesions on the oral side. The images of the oral side of the colon were good enough to allow adequate interpretation in 9 of the 10 patients. In the first patient, the visualization of the area near the lesion was somewhat fair, although the right side colon was well visualized. There were no complications associated with this examination. The present preoperative examination using a transanal drainage tube was useful for determining the extent of intestinal resection when patients were not candidates for colonoscopy or barium enema examination. (author)

  5. Comparison of the diagnostic performance of CT colonography interpreted by radiologists and radiographers

    DEFF Research Database (Denmark)

    Lauridsen, Carsten; Lefere, Philippe; Gerke, Oke

    2013-01-01

    OBJECTIVE: To compare computed tomographic colonography (CTC) performance of four trained radiographers with the CTC performance of two experienced radiologists. METHODS: Four radiographers and two radiologists interpreted 87 cases with 40 polyps ≥6 mm. Sensitivity, specificity, and positive...

  6. At what costs will screening with CT colonography be competitive? A cost-effectiveness approach

    NARCIS (Netherlands)

    I. Lansdorp-Vogelaar (Iris); M. van Ballegooijen (Marjolein); A. Zauber (Ann); R. Boer (Rob); J.A. Wilschut (Janneke); J.D.F. Habbema (Dik)

    2009-01-01

    textabstractThe costs of computed tomographic colonography (CTC) are not yet established for screening use. In our study, we estimated the threshold costs for which CTC screening would be a cost-effective alternative to colonoscopy for colorectal cancer (CRC) screening in the general population. We

  7. 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

  8. Computer-aided detection of polyps in CT colonography using logistic regression

    NARCIS (Netherlands)

    van Ravesteijn, Vincent F.; van Wijk, Cees; Vos, Frans M.; Truyen, Roel; Peters, Joost F.; Stoker, Jaap; van Vliet, Lucas J.

    2010-01-01

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

  9. Colonic angiodysplasia on CT colonography: case report and characteristic imaging findings

    Directory of Open Access Journals (Sweden)

    Laura Filograna, MD

    2017-12-01

    Full Text Available Gastrointestinal angiodysplasia represents the cause of 6% of lower gastrointestinal tract bleeding, particularly in the elderly. Because of the common presentation and age range of affected patients, often patients with occult or massive gastrointestinal bleedings are investigated with colonoscopy, in the suspect of colonic cancer. Other methods are capsule enteroscopy, angiography, double-contrast barium enema, computed tomography angiography, and radionuclide scanning. In this contribution, we describe a case of colonic angiodysplasia first suspected during computed tomography colonography performed after an incomplete colonoscopy in a patient with recent anemization. The purpose is to highlight the computed tomography colonography imaging characteristics of this rare finding during such examination performed due to suspected colon carcinoma as a complementary or substitutive method of colonoscopy.

  10. Volumetric analysis of colonic distention according to patient position at CT colonography: diagnostic value of the right lateral decubitus series.

    Science.gov (United States)

    Pickhardt, Perry J; Bakke, Joshua; Kuo, Jarret; Robbins, Jessica B; Lubner, Meghan G; del Rio, Alejandro Muñoz; Kim, David H

    2014-12-01

    The purpose of this study was to compare total colonic gas volume and segmental luminal distention according to patient position on CT colonography (CTC), as well as to determine which two views should constitute the routine protocol. Volumetric analysis was retrospectively performed on CTC examinations from 146 adults (mean age, 59.2 years; 81 men and 65 women; mean body mass index [BMI], 30.9) for whom supine, prone, and right lateral decubitus series were sequentially obtained using continuous low-pressure CO2 insufflation. Total colonic gas volumes were assessed using a novel automated volumetric tool. In addition, two radiologists scored distention by segment using a 4-point scale (4=optimal; 3=adequate; 2=inadequate; 1=collapsed). Mean (±SD) colonic gas volumes for supine, prone, and decubitus positioning were 1617±567, 1441±505, and 1901±627, respectively (pvolumetric analysis provides for rapid objective assessment of colonic distention.

  11. 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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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 < 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.)

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

    International Nuclear Information System (INIS)

    Luboldt, W.; Kroll, M.; Wetter, A.; Vogl, T.J.; Toussaint, T.L.; Hoepffner, N.; Holzer, K.; Kluge, A.

    2004-01-01

    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 0 . The slope m was determined by linear regression in the correlation (lesion ∝[xA + (1 - x)V]//H) and the Y-intercept y 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 improves when the cut-off is adjusted (normalized) to the contrast phase and lesion size. (orig.)

  13. CT colonography versus double-contrast barium enema for screening of colorectal cancer: comparison of radiation burden.

    Science.gov (United States)

    Neri, Emanuele; Faggioni, Lorenzo; Cerri, Francesca; Turini, Francesca; Angeli, Simone; Cini, Lorenzo; Perrone, Franco; Paolicchi, Fabio; Bartolozzi, Carlo

    2010-10-01

    Our aim is to compare the radiation dose associated with a low-dose CT colonography (CTC) protocol for colorectal cancer screening with that delivered by double-contrast barium enema (DCBE). CTC of twenty asymptomatic individuals (M:F = 10:10) participating to a colorectal cancer screening program and DCBE of fifteen patients (M:F = 6:9) were evaluated. For CTC, absorbed dose was determined by calculating the dose-length product for each CTC examination from measurements on a CT dose phantom equipped with a CT ion chamber. For DCBE, the free-in-air Kerma at the patient's X-ray entry surface and the Kerma-area product during fluoroscopy and fluorography were measured with a Barracuda system, with fluoroscopy times being recorded blinded to the performing operator. Effective dose at CTC was 2.17 ± 0.12 mSv, with good and excellent image quality in 14/20 (70%) and 6/20 cases (30%), respectively. With DCBE, effective patient dose was 4.12 ± 0.17 mSv, 1.9 times greater than CTC (P < 0.0001). Our results show that effective dose from screening CTC is substantially lower than that from DCBE, suggesting that CTC is the radiological imaging technique of the large bowel with the lowest risk of stochastic radiation effects.

  14. Accuracy of Combined Computed Tomography Colonography and Dual Energy Iiodine Map Imaging for Detecting Colorectal masses using High-pitch Dual-source CT.

    Science.gov (United States)

    Sun, Kai; Han, Ruijuan; Han, Yang; Shi, Xuesen; Hu, Jiang; Lu, Bin

    2018-02-28

    To evaluate the diagnostic accuracy of combined computed tomography colonography (CTC) and dual-energy iodine map imaging for detecting colorectal masses using high-pitch dual-source CT, compared with optical colonography (OC) and histopathologic findings. Twenty-eight consecutive patients were prospectively enrolled in this study. All patients were underwent contrast-enhanced CTC acquisition using dual-energy mode and OC and pathologic examination. The size of the space-occupied mass, the CT value after contrast enhancement, and the iodine value were measured and statistically compared. The sensitivity, specificity, accuracy rate, and positive predictive and negative predictive values of dual-energy contrast-enhanced CTC were calculated and compared between conventional CTC and dual-energy iodine images. The iodine value of stool was significantly lower than the colonic neoplasia (P dual-energy iodine maps imaging was 95.6% (95% CI = 77.9%-99.2%). The specificity of the two methods was 42.8% (95% CI = 15.4%-93.5%) and 100% (95% CI = 47.9%-100%; P = 0.02), respectively. Compared with optical colonography and histopathology, combined CTC and dual-energy iodine maps imaging can distinguish stool and colonic neoplasia, distinguish between benign and malignant tumors initially and improve the diagnostic accuracy of CTC for colorectal cancer screening.

  15. Preliminary evaluation of helical CT colonography in detection of colonic diseases compared with double contrast barium enema

    International Nuclear Information System (INIS)

    Zhai Xiaoli; Zhang Lei; Zhai Renyou; Li Jie; Wang Yajie; Ding Yi

    2000-01-01

    Objective: To evaluate helical CT colonography in regard to technology principles, limitations, and clinical applications. Methods: Fifty-six patients underwent volume scanning using helical CT. The diseases included adenocarcinoma 39, adenomatous polyp 3, multiple diverticular 7, mucocele of appendix 1, and normal colon 6. All cases had been compared with double contrast barium enema (DCBE), proved by histology except the 6 normal colon and the 7 multiple diverticular. All CTC images were reconstructed using shaded surface display (SSD) on workstation. Then, perspective images such as the ones from DCBE were generated via ray sum. The images could clearly demonstrate the extent and detail of the disorder by using 'CUT' software, 'revolve' function, and zoom. Results: CTC correctly demonstrated 3-5 mm diverticulum, 3 mm ulcer, and 6 mm polyps. Not only show colon straitness clearly, CTC is also very sensitive to demonstrate the stenotic end of masses. In these cases, discovery rate of CTC is 100.0%, the rate of DCBE is 88.6%; CTC is more sensitive than DCBE in cases of tumor nodules. Ray sum can show the boundary of colonic mass extending to both proximal and distal ends, its discovery rate is 62.6%. Accuracy of localization for CTC is 100.0%. Conclusion: CTC is a novel technique for detecting colonic diseases. It is a safe, accurate, and non-invasive means for detection of lesions and is an efficient complement for DCBE. Further development in CTC technique is expected in the future

  16. 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.

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

    International Nuclear Information System (INIS)

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

    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

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

    International Nuclear Information System (INIS)

    Helbren, Emma; Taylor, Stuart A.; Fanshawe, Thomas R.; Mallett, Susan; Phillips, Peter; Boone, Darren; Gale, Alastair; Altman, Douglas G.; Manning, David; Halligan, Steve

    2015-01-01

    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.)

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

    International Nuclear Information System (INIS)

    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

  20. 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.)

  1. Dry preparation for virtual CT colonography with fecal tagging using water-soluble contrast medium: initial results

    International Nuclear Information System (INIS)

    Bielen, Didier; Thomeer, Maarten; Vanbeckevoort, Dirk; Marchal, Guy; Kiss, Gabriel; Maes, Frederik; Rutgeerts, Paul

    2003-01-01

    The purpose of this study was to evaluate the feasibility of a dry bowel preparation, i.e. without laxative fluids, for virtual CT colonography (VCTC), and its impact on patient acceptance compared with conventional colonoscopy (CC). A randomly chosen patient population scheduled for CC (n=11) was first submitted to VCTC after a dry preparation, consisting of low-residue meals combined with a small amount of a iodinated water-soluble contrast medium during each meal 3 days before VCTC. In different colon segments and between different persons, the degree of tagging in VCTC was evaluated and graded. Patient acceptance and future preference were assessed for both preparations as well as for both investigations. The mixing of the contrast with the intestinal content results in contrast impregnated stool, the tagged feces. The degree of fecal tagging was good in the majority of the patients and the colonic segments, especially in the descending colon and sigmoid. Furthermore, patient acceptance and preference were clearly in favour of VCTC compared with CC merely because of the non-invasiveness of the dry preparation. Dry bowel preparation and VCTC is a promising approach towards a patient-friendly colon cancer-screening setup. (orig.)

  2. 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.)

  3. 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.)

  4. Measurement of smaller colon polyp in CT colonography images using morphological image processing.

    Science.gov (United States)

    Manjunath, K N; Siddalingaswamy, P C; Prabhu, G K

    2017-11-01

    Automated measurement of the size and shape of colon polyps is one of the challenges in Computed tomography colonography (CTC). The objective of this retrospective study was to improve the sensitivity and specificity of smaller polyp measurement in CTC using image processing techniques. A domain knowledge-based method has been implemented with hybrid method of colon segmentation, morphological image processing operators for detecting the colonic structures, and the decision-making system for delineating the smaller polyp-based on a priori knowledge. The method was applied on 45 CTC dataset. The key finding was that the smaller polyps were accurately measured. In addition to 6-9 mm range, polyps of even <5 mm were also detected. The results were validated qualitatively and quantitatively using both 2D MPR and 3D view. Implementation was done on a high-performance computer with parallel processing. It takes [Formula: see text] min for measuring the smaller polyp in a dataset of 500 CTC images. With this method, [Formula: see text] and [Formula: see text] were achieved. The domain-based approach with morphological image processing has given good results. The smaller polyps were measured accurately which helps in making right clinical decisions. Qualitatively and quantitatively the results were acceptable when compared to the ground truth at [Formula: see text].

  5. Comparison of three different iodine-based bowel regimens for CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Campanella, Delia; Regge, Daniele [Institute for Cancer Research and Treatment, Radiology Unit, Candiolo (Italy); Morra, Lia; Delsanto, Silvia; Bert, Alberto [im3D S.p.A., Turin (Italy); Tartaglia, Vincenzo [Presidio Ospedaliero Riunito Cirie, ASL 4 Torino, Cirie (Italy); Asnaghi, Roberto [Istituto Scientifico di Veruno, Radiologia, Fondazione Salvatore Maugeri, IRCCS, Veruno, NO (Italy); Neri, Emanuele [University of Pisa, Diagnostic and Interventional Radiology, Pisa (Italy)

    2010-02-15

    The aim of this study was to compare the computed tomographic colonography (CTC) image quality and patient acceptance of three iodine-based faecal tagging bowel preparations in 60 patients undergoing the following regimens: a 2-day regimen of meal-time administration of iodine and phospho-soda (GFPH); a 2-day regimen of meal-time mild laxative, followed by iodine administered 2 h before CTC (SD); and a 2-day regimen of meal-time administration of iodine (GF). Two independent radiologists assessed tagging quality; quantitative measures included the tagged stool density, and computer-aided detection (CAD) false-positive rate. The GFPH and SD regimens provided better subjective quality than GF (p < 0.001). The latter regimen resulted in a higher proportion of insufficiently tagged segments: the measured average stool density was less than 200 HU in 10.7% in all segments vs 3.6% for SD and <0.5% for GFPH, respectively. Insufficient tagging occurred mostly in the ascending colon and the caecum. The CAD false-positive rate increased following the trend: GFPH < SD < GF (p = 0.00012). GFPH was worse tolerated than SD (p < 0.05). Considering preparation quality alone, GFPH was the best regimen, but SD provided the best balance between bowel preparation quality and patient acceptability. (orig.)

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

    International Nuclear Information System (INIS)

    Haan, Margriet C. de; Boellaard, Thierry N.; Bossuyt, Patrick M.; Stoker, Jaap

    2012-01-01

    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.

  7. 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.

  8. 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.)

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

    International Nuclear Information System (INIS)

    Plumb, Andrew A.; Pathiraja, Fiona; Taylor, Stuart A.; Halligan, Steve; Nickerson, Claire; Wooldrage, Katherine; Atkin, Wendy S.; Burling, David

    2016-01-01

    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 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.)

  10. Reducing the oral contrast dose in CT colonography: evaluation of faecal tagging quality and patient acceptance

    International Nuclear Information System (INIS)

    Liedenbaum, M.H.; Denters, M.J.; Zijta, F.M.; Ravesteijn, V.F. van; Bipat, S.; Vos, F.M.; Dekker, E.; Stoker, J.

    2011-01-01

    Aim: To evaluate the minimal iodine contrast medium load necessary for an optimal computed tomography colonography tagging quality. Materials and Methods: Faecal occult blood test positive patients were randomly selected for one of three iodine bowel preparations: (1) 3 x 50 ml meglumine ioxithalamate (45 g iodine), (2) 4 x 25 ml meglumine ioxithalamate (30 g iodine); or (3) 3 x 25 ml (22.5 g iodine) meglumine ioxithalamate. Two experienced readers assessed the tagging quality per colonic segment on a five-point scale and the presence of adherent stool. Also semi-automatic homogeneity measurements were performed. Patient acceptance was assessed with questionnaires. Results: Of 70 eligible patients, 45 patients participated (25 males, mean age 62 years). Each preparation group contained 15 patients. The quality of tagging was insufficient (score 1-2) in 0% of segments in group 1; 4% in group 2 (p < 0.01 versus group 1); and 5% in group 3 (p = 0.06 versus group 1). In group 1 in 11% of the segments adherent stool was present compared with 49% in group 2 and 41% in group 3 (p < 0.01, group 2 and 3 versus group 1). Homogeneity was 85, 102 (p < 0.01), and 91 SD HU (p = 0.26) in groups 1, 2, and 3, respectively. In group 1 two patients experienced no burden after contrast agent ingestion compared to one patient in group 2 and nine patients in group 3 (p = 0.017). Conclusion: A dose of 3 x 50 ml meglumine ioxithalamate is advisable for an optimal tagging quality despite beneficial effects on the patient acceptance in patients receiving a lower dose.

  11. Registration of prone and supine CT colonography scans using correlation optimized warping and canonical correlation analysis

    International Nuclear Information System (INIS)

    Wang Shijun; Yao Jianhua; Liu Jiamin; Petrick, Nicholas; Van Uitert, Robert L.; Periaswamy, Senthil; Summers, Ronald M.

    2009-01-01

    Purpose: In computed tomographic colonography (CTC), a patient will be scanned twice--Once supine and once prone--to improve the sensitivity for polyp detection. To assist radiologists in CTC reading, in this paper we propose an automated method for colon registration from supine and prone CTC scans. Methods: We propose a new colon centerline registration method for prone and supine CTC scans using correlation optimized warping (COW) and canonical correlation analysis (CCA) based on the anatomical structure of the colon. Four anatomical salient points on the colon are first automatically distinguished. Then correlation optimized warping is applied to the segments defined by the anatomical landmarks to improve the global registration based on local correlation of segments. The COW method was modified by embedding canonical correlation analysis to allow multiple features along the colon centerline to be used in our implementation. Results: We tested the COW algorithm on a CTC data set of 39 patients with 39 polyps (19 training and 20 test cases) to verify the effectiveness of the proposed COW registration method. Experimental results on the test set show that the COW method significantly reduces the average estimation error in a polyp location between supine and prone scans by 67.6%, from 46.27±52.97 to 14.98 mm±11.41 mm, compared to the normalized distance along the colon centerline algorithm (p<0.01). Conclusions: The proposed COW algorithm is more accurate for the colon centerline registration compared to the normalized distance along the colon centerline method and the dynamic time warping method. Comparison results showed that the feature combination of z-coordinate and curvature achieved lowest registration error compared to the other feature combinations used by COW. The proposed method is tolerant to centerline errors because anatomical landmarks help prevent the propagation of errors across the entire colon centerline.

  12. CT colonography: accuracy of initial interpretation by radiographers in routine clinical practice

    International Nuclear Information System (INIS)

    Burling, D.; Wylie, P.; Gupta, A.; Illangovan, R.; Muckian, J.; Ahmad, R.; Marshall, M.; Taylor, S.A.

    2010-01-01

    Aim: To investigate performance of computed-assisted detection (CAD)-assisted radiographers interpreting computed tomography colonography (CTC) in routine practice. Materials and methods: Three hundred and three consecutive symptomatic patients underwent CTC. Examinations were double-read by trained radiographers using primary two-dimensional/three-dimensional (2D/3D) analysis supplemented by 'second reader' CAD. Radiographers recorded colonic neoplasia, interpretation times, and patient management strategy code (S0, inadequate; S1, normal; S2, 6-9 mm polyp; S3, ≥10 mm polyp; S4, cancer; S5, diverticular stricture) for each examination. Strategies were compared to the reference standard using kappa statistic, interpretation times using paired t-test, learning curves using logistic regression and Pearson's correlation coefficient. Results: Of 303 examinations, 69 (23%) were abnormal. CAD-assisted radiographers detected 17/17 (100%) cancers, 21/28 (72%) polyps ≥10 mm and 42/60 (70%) 6-9 mm polyps. The overall agreement between radiographers and the reference management strategy was good (kappa 0.72; CI: 0.65, 0.78) with agreement for S1 strategy in 189/211 (90%) exams; S2 in 19/27 (70%); S3 in 12/19 (63%); S4 in 17/17 (100%); S5 in 5/6 (83%). The mean interpretation time was 17 min (SD = 11) compared with 8 min (SD = 3.5) for radiologists. There was no learning curve for recording correct strategies (OR 0.88; p = 0.12) but a significant reduction in interpretation times, mean 14 and 31 min (last/first 50 exams; -0.46; p < 0.001). Conclusion: Routine CTC interpretation by radiographers is effective for initial triage of patients with cancer, but independent reporting is currently not recommended.

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

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    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.

  14. 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

    Objectives To quantify the incremental benefit of computer-assisted-detection (CAD) for polyps, for inexperienced readers versus experienced readers of CT colonography. Methods 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. Results 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. Conclusions 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. PMID:26355745

  15. Comparison between CT colonography and double-contrast barium enema for colonic evaluation in patients with renal insufficiency.

    Science.gov (United States)

    Chung, Sun-Young; Park, Seong Ho; Lee, Seung Soo; Lee, Ju Hee; Kim, Ah Young; Park, Su-Kil; Han, Duck Jong; Ha, Hyun Kwon

    2012-01-01

    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.

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

    International Nuclear Information System (INIS)

    Jang, Jong eon; Park, Seong Ho; Lee, Jong Seok; Kim, Hyun Jin; KIm, Ah Young; Ha, Hyun Kwon

    2016-01-01

    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

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

    International Nuclear Information System (INIS)

    Chung, Sun Young; Park, Seong Ho; Lee, Seung Soo; Lee, Ju Hee; Kim, Ah Young; Park, Su Ki; Han, Duck Jong; Ha, Hyun Kwon

    2012-01-01

    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.

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

    International Nuclear Information System (INIS)

    Plumb, Andrew A.; Taylor, Stuart A.; Halligan, Steve; Ghanouni, Alex; Von Wagner, Christian; Rees, Colin J.; Hewitson, Paul; Nickerson, Claire; Wright, Suzanne

    2017-01-01

    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.)

  19. 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.)

  20. Simethicone to prevent colonic bubbles during CT colonography performed with polyethylene glycol lavage and iohexol tagging: a randomized clinical trial.

    Science.gov (United States)

    Hong, Gil-Sun; Park, Seong Ho; Kim, Bohyun; Lee, Ju Hee; Kim, Jin Cheon; Yu, Chang Sik; Baek, Seunghee; Lee, Jong Seok; Kim, Hyun Jin

    2015-04-01

    The purpose of this study was to determine whether the occurrence of numerous colonic bubbles during CT colonography (CTC) performed with polyethylene glycol cleansing and oral iohexol fecal/fluid tagging could be prevented by use of simethicone. Adults with suspected colonic neoplasia who had been randomly assigned to control and simethicone intervention groups underwent CTC after cleansing with 4 L of polyethylene glycol, tagging with 50 mL of 350 mg I/mL oral iohexol, and without (control) or with (intervention) oral administration of 200 mg of simethicone. Colonic segments in the control and intervention groups were evaluated for amount of colonic bubbles during CTC. A 6-point grading system was used in which 0 indicated no bubbles and 5 indicated that more than three fourths of the air-distended mucosa was covered with bubbles. The primary endpoint was a per-patient colonic bubble grade, derived as an average of the segmental grades. Eighty adults with suspected colonic neoplasia were randomly assigned to the control (40 patients) and simethicone intervention (40 patients) groups. A total of 659 colonic segments in the control group and 689 segments in the intervention group were evaluated for amount of colonic bubbles during CTC. The per-patient colonic bubble score was significantly lower in the simethicone intervention group than in the control group. The mean score was 0.0±0.1 (SD) versus 1.2±0.8 (pgrade 0, and 16 (2.3%) were grade 1. In contrast, in the control group, 226 (34.3%) segments were grade 0; 173 (26.3%), grade 1; 175 (26.6%), grade 2; 45 (6.8%), grade 3; 23 (3.5%), grade 4; and 17 (2.6%), grade 5. The colonic bubbles associated with fecal/fluid tagging with iohexol can be successfully prevented by adding simethicone to the colonic preparation.

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

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    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.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

  3. Computer assisted detection software for CT colonography: effect of sphericity filter on performance characteristics for patients with and without fecal tagging

    International Nuclear Information System (INIS)

    Dehmeshki, Jamshid; McQuillan, Justine; Honeyfield, Lesley; Amin, Hamdan; Halligan, Steve; Taylor, Stuart A.; Roddie, Mary E.

    2007-01-01

    The aim of this study is to investigate the effect of changing sphericity filter values on performance of a computer assisted detection (CAD) system for CT colonography for data with and without fecal tagging. Colonography data from 138 patients with 317 validated polyps were divided into those with (86) and without (52) fecal tagging. Polyp coordinates were established by three observers and datasets analysed subsequently by a proprietary CAD system used at four discrete sphericity filter settings. Prompts were compared with the known coordinates in order to determine sensitivity and specificity. Sensitivity was highest at low sphericity; of 164 polyps 6 mm or more, 144 (87.8%) were detected at sphericity 0.3, and 132 (80.1%) at sphericity 0.9. Of 42 polyps measuring 10 mm or more, 40 (95.2%) were detected at sphericity 0.3, and 36 (85.7%) at sphericity 0.9. There was no significant difference in sensitivity for tagged and un-tagged data but specificity was reduced in tagged data at low sphericity and significantly reduced in untagged data at high sphericity. CAD had a sensitivity of 95.2% for polyps measuring 1 cm or more and 87.8% for polyps 6 mm or more when used at a sphericity setting of 0.3. Higher sphericity settings increased specificity while reducing sensitivity. The bowel preparation used significantly impacts on specificity. (orig.)

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

    Science.gov (United States)

    Neri, Emanuele; Mantarro, Annalisa; Faggioni, Lorenzo; Scalise, Paola; Bemi, Pietro; Pancrazi, Francesca; D'Ippolito, Giuseppe; Bartolozzi, Carlo

    2015-09-01

    To evaluate feasibility, diagnostic performance, patient acceptance, and overall examination time of CT colonography (CTC) performed through rectal administration of iodinated contrast material. 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). Mean per-polyp sensitivity, specificity, positive and negative predictive values of CTC with rectal vs oral tagging were 96.1% (CI95% 85.4÷99.3%) vs 89.4% (CI95% 65.4÷98.1%), 95.3% (CI95% 90.7÷97.8%) vs 95.8% (CI95% 87.6÷98.9%), 86.0% (CI95% 73.6÷93.3) vs 85.0% (CI95% 61.1÷96.0%), and 98.8% (CI95% 95.3÷99.8%) vs 97.2% (CI95% 89.4÷99.5%), respectively (p>0.05). Polyp detection rates were not statistically different between groups 1 and 2 (p>0.05). Overall examination time was significantly shorter with rectal than with oral tagging (18.3±3.5 vs 215.6±10.3 minutes, respectively; pRectal iodine tagging can be an effective alternative to oral tagging for CTC with the advantages of greater patient acceptance and lower overall examination time. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. 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

  6. Quantifying public preferences for different bowel preparation options prior to screening CT colonography: a discrete choice experiment.

    Science.gov (United States)

    Ghanouni, Alex; Halligan, Steve; Taylor, Stuart A; Boone, Darren; Plumb, Andrew; Stoffel, Sandro; Morris, Stephen; Yao, Guiqing Lily; Zhu, Shihua; Lilford, Richard; Wardle, Jane; von Wagner, Christian

    2014-04-03

    CT colonography (CTC) may be an acceptable test for colorectal cancer screening but bowel preparation can be a barrier to uptake. This study tested the hypothesis that prospective screening invitees would prefer full-laxative preparation with higher sensitivity and specificity for polyps, despite greater burden, over less burdensome reduced-laxative or non-laxative alternatives with lower sensitivity and specificity. Discrete choice experiment. Online, web-based survey. 2819 adults (45-54 years) from the UK responded to an online invitation to take part in a cancer screening study. Quota sampling ensured that the sample reflected key demographics of the target population and had no relevant bowel disease or medical qualifications. The analysis comprised 607 participants. After receiving information about screening and CTC, participants completed 3-4 choice scenarios. Scenarios showed two hypothetical forms of CTC with different permutations of three attributes: preparation, sensitivity and specificity for polyps. Participants considered the trade-offs in each scenario and stated their preferred test (or chose neither). Preparation and sensitivity for polyps were both significant predictors of preferences (coefficients: -3.834 to -6.346 for preparation, 0.207-0.257 for sensitivity; p<0.0005). These attributes predicted preferences to a similar extent. Realistic specificity values were non-significant (-0.002 to 0.025; p=0.953). Contrary to our hypothesis, probabilities of selecting tests were similar for realistic forms of full-laxative, reduced-laxative and non-laxative preparations (0.362-0.421). However, they were substantially higher for hypothetical improved forms of reduced-laxative or non-laxative preparations with better sensitivity for polyps (0.584-0.837). Uptake of CTC following non-laxative or reduced-laxative preparations is unlikely to be greater than following full-laxative preparation as perceived gains from reduced burden may be diminished by

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

    International Nuclear Information System (INIS)

    Park, Hee Sun; Kim, Se Hyung; Kim, Jong Hyo; Lee, June-Goo; Kim, Sang Gyun; Lee, Jeong Min; Lee, Jae Young; Han, Joon Koo; Choi, Byung Ihn

    2010-01-01

    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-based CAD

  8. 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

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    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

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

    International Nuclear Information System (INIS)

    Lee, Eun Sun; Kim, Se Hyung; Im, Jong Pil; Kim, Sang Gyun; Shin, Cheong-il; Han, Joon Koo; Choi, Byung Ihn

    2015-01-01

    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

  10. 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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  12. An interview study analysing patients' experiences and perceptions of non-laxative or full-laxative preparation with faecal tagging prior to CT colonography

    International Nuclear Information System (INIS)

    Ghanouni, A.; Smith, S.G.; Halligan, S.; Taylor, S.A.; Plumb, A.; Boone, D.; Wagner, C. von

    2013-01-01

    Aim: To compare patients' experiences of either non- or full-laxative bowel preparation with additional faecal tagging and subsequent computed tomographic (CT) colonography using in-depth interviews to elicit detailed responses. Materials and methods: Patients who received CT colonography after non- (n = 9) or full-laxative (n = 9) preparation participated in a semi-structured telephone interview at least 2 days after the investigation. Full-laxative preparation consisted of magnesium citrate and sodium picosulphate administered at home (or polyethylene glycol, if contraindicated), followed by hospital-based faecal tagging with iohexol. Non-laxative preparation was home-based barium sulphate for faecal tagging. Interviews were transcribed and thematically analysed to identify recurrent themes on patients' perceptions and experiences. Results: Experiences of full-laxative preparation were usually negative and characterized by pre-test diarrhoea that caused significant interference with daily routine. Post-test flatus was common. Non-laxative preparation was well-tolerated; patients reported no or minimal changes to bowel habit and rapid return to daily routine. Patients reported worry and uncertainty about the purpose of faecal tagging. For iohexol, this also added burden from waiting before testing. Conclusion: Patients' responses supported previous findings that non-laxative preparation is more acceptable than full-laxative preparation but both can be improved. Faecal tagging used in combination with laxative preparation is poorly understood, adding burden and worry. Home-based non-laxative preparation is also poorly understood and patients require better information on the purpose and mechanism in order to give fully informed consent. This may also optimize adherence to instructions. Allowing home-based self-administration of all types of preparation would prevent waiting before testing

  13. Improved classifier for computer-aided polyp detection in CT Colonography by nonlinear dimensionality reduction

    Science.gov (United States)

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

    2008-01-01

    Computer-aided detection (CAD) has been shown to be feasible for polyp detection on computed tomography (CT) scans. After initial detection, the dataset of colonic polyp candidates has large-scale and high dimensional characteristics. In this article, we propose a nonlinear dimensionality reduction method based on diffusion map and locally linear embedding (DMLLE) for large-scale datasets. By selecting partial data as landmarks, we first map these points into a low dimensional embedding space using the diffusion map. The embedded landmarks can be viewed as a skeleton of whole data in the low dimensional space. Then by using the locally linear embedding algorithm, nonlandmark samples are mapped into the same low dimensional space according to their nearest landmark samples. The local geometry is preserved in both the original high dimensional space and the embedding space. In addition, DMLLE provides a faithful representation of the original high dimensional data at coarse and fine scales. Thus, it can capture the intrinsic distance relationship between samples and reduce the influence of noisy features, two aspects that are crucial to achieving high classifier performance. We applied the proposed DMLLE method to a colonic polyp dataset of 175 269 polyp candidates with 155 features. Visual inspection shows that true polyps with similar shapes are mapped to close vicinity in the low dimensional space. We compared the performance of a support vector machine (SVM) classifier in the low dimensional embedding space with that in the original high dimensional space, SVM with principal component analysis dimensionality reduction and SVM committee using feature selection technology. Free-response receiver operating characteristic analysis shows that by using our DMLLE dimensionality reduction method, SVM achieves higher sensitivity with a lower false positive rate compared with other methods. For 6–9mm polyps (193 true polyps contained in test set), when the number of

  14. Improved classifier for computer-aided polyp detection in CT colonography by nonlinear dimensionality reduction.

    Science.gov (United States)

    Wang, Shijun; Yao, Jianhua; Summers, Ronald M

    2008-04-01

    Computer-aided detection (CAD) has been shown to be feasible for polyp detection on computed tomography (CT) scans. After initial detection, the dataset of colonic polyp candidates has large-scale and high dimensional characteristics. In this article, we propose a nonlinear dimensionality reduction method based on diffusion map and locally linear embedding (DMLLE) for large-scale datasets. By selecting partial data as landmarks, we first map these points into a low dimensional embedding space using the diffusion map. The embedded landmarks can be viewed as a skeleton of whole data in the low dimensional space. Then by using the locally linear embedding algorithm, nonlandmark samples are mapped into the same low dimensional space according to their nearest landmark samples. The local geometry is preserved in both the original high dimensional space and the embedding space. In addition, DMLLE provides a faithful representation of the original high dimensional data at coarse and fine scales. Thus, it can capture the intrinsic distance relationship between samples and reduce the influence of noisy features, two aspects that are crucial to achieving high classifier performance. We applied the proposed DMLLE method to a colonic polyp dataset of 175 269 polyp candidates with 155 features. Visual inspection shows that true polyps with similar shapes are mapped to close vicinity in the low dimensional space. We compared the performance of a support vector machine (SVM) classifier in the low dimensional embedding space with that in the original high dimensional space, SVM with principal component analysis dimensionality reduction and SVM committee using feature selection technology. Free-response receiver operating characteristic analysis shows that by using our DMLLE dimensionality reduction method, SVM achieves higher sensitivity with a lower false positive rate compared with other methods. For 6-9 mm polyps (193 true polyps contained in test set), when the number of false

  15. 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

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

    International Nuclear Information System (INIS)

    Neri, Emanuele; Mantarro, Annalisa; Faggioni, Lorenzo; Scalise, Paola; Bemi, Pietro; Pancrazi, Francesca; D’Ippolito, Giuseppe; Bartolozzi, Carlo

    2015-01-01

    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 95% 85.4 ÷ 99.3%) vs 89.4% (CI 95% 65.4 ÷ 98.1%), 95.3% (CI 95% 90.7 ÷ 97.8%) vs 95.8% (CI 95% 87.6 ÷ 98.9%), 86.0% (CI 95% 73.6 ÷ 93.3) vs 85.0% (CI 95% 61.1 ÷ 96.0%), and 98.8% (CI 95% 95.3 ÷ 99.8%) vs 97.2% (CI 95% 89

  17. Evidence-based investigation of the influence of computer-aided detection of polyps on screening of colon cancer with CT colonography

    International Nuclear Information System (INIS)

    Yoshida, Hiroyuki

    2008-01-01

    Computed tomographic colonography (CTC), also known as virtual colonoscopy, is a CT examination of the colon for colorectal neoplasms. Recent large-scale clinical trials have demonstrated that CTC yields sensitivity comparable to optical colonoscopy in the detection of clinically significant polyps in a screening population, making CTC a promising technique for screening of colon cancer. For CTC to be a clinically practical means of screening, it must reliably and consistently detect polyps with high accuracy. However, high-level expertise is required to interpret the resulting CT images to find polyps, resulting in variable diagnostic accuracy among radiologists in the detection of polyps. A key technology to overcome this problem and to bring CTC to prime time for screening of colorectal cancer is computer-aided detection (CAD) of polyps. CAD automatically detects the locations of suspicious polyps in CTC images and presents them to radiologists. CAD has the potential to increase diagnostic performance in the detection of polyps as well as to reduce variability of the diagnostic accuracy among radiologists. This paper presents an evidence-based investigation of the influence of CAD on screening of colon cancer with CTC by describing the benefits of using CAD in the diagnosis of CTC, the fundamental CAD scheme for the detection of polyps in CTC, its detection performance, the effect on the improvement of detection performance, as well as the current and future challenges in CAD. (author)

  18. Does the amount of tagged stool and fluid significantly affect the radiation exposure in low-dose CT colonography performed with an automatic exposure control?

    International Nuclear Information System (INIS)

    Lim, Hyun Kyong; Lee, Kyoung Ho; Kim, So Yeon; Kim, Young Hoon; Kim, Kil Joong; Kim, Bohyoung; Lee, Hyunna; Park, Seong Ho; Yanof, Jeffrey H.; Hwang, Seung-sik

    2011-01-01

    To determine whether the amount of tagged stool and fluid significantly affects the radiation exposure in low-dose screening CT colonography performed with an automatic tube-current modulation technique. The study included 311 patients. The tagging agent was barium (n = 271) or iodine (n = 40). Correlation was measured between mean volume CT dose index (CTDI vol ) and the estimated x-ray attenuation of the tagged stool and fluid (ATT). Multiple linear regression analyses were performed to determine the effect of ATT on CTDI vol and the effect of ATT on image noise while adjusting for other variables including abdominal circumference. CTDI vol varied from 0.88 to 2.54 mGy. There was no significant correlation between CTDI vol and ATT (p = 0.61). ATT did not significantly affect CTDI vol (p = 0.93), while abdominal circumference was the only factor significantly affecting CTDI vol (p < 0.001). Image noise ranged from 59.5 to 64.1 HU. The p value for the regression model explaining the noise was 0.38. The amount of stool and fluid tagging does not significantly affect radiation exposure. (orig.)

  19. Prior image constrained compressed sensing metal artifact reduction (PICCS-MAR): 2D and 3D image quality improvement with hip prostheses at CT colonography

    International Nuclear Information System (INIS)

    Bannas, Peter; Li, Yinsheng; Motosugi, Utaroh; Li, Ke; Chen, Guang-Hong; Lubner, Meghan; Pickhardt, Perry J.

    2016-01-01

    To assess the effect of the prior-image-constrained-compressed-sensing-based metal-artefact-reduction (PICCS-MAR) algorithm on streak artefact reduction and 2D and 3D-image quality improvement in patients with total hip arthroplasty (THA) undergoing CT colonography (CTC). PICCS-MAR was applied to filtered-back-projection (FBP)-reconstructed DICOM CTC-images in 52 patients with THA (unilateral, n = 30; bilateral, n = 22). For FBP and PICCS-MAR series, ROI-measurements of CT-numbers were obtained at predefined levels for fat, muscle, air, and the most severe artefact. Two radiologists independently reviewed 2D and 3D CTC-images and graded artefacts and image quality using a five-point-scale (1 = severe streak/no-diagnostic confidence, 5 = no streak/excellent image-quality, high-confidence). Results were compared using paired and unpaired t-tests and Wilcoxon signed-rank and Mann-Whitney-tests. Streak artefacts and image quality scores for FBP versus PICCS-MAR 2D-images (median: 1 vs. 3 and 2 vs. 3, respectively) and 3D images (median: 2 vs. 4 and 3 vs. 4, respectively) showed significant improvement after PICCS-MAR (all P < 0.001). PICCS-MAR significantly improved the accuracy of mean CT numbers for fat, muscle and the area with the most severe artefact (all P < 0.001). PICCS-MAR substantially reduces streak artefacts related to THA on DICOM images, thereby enhancing visualization of anatomy on 2D and 3D CTC images and increasing diagnostic confidence. (orig.)

  20. Patient acceptability of CT colonography compared with double contrast barium enema: results from a multicentre randomised controlled trial of symptomatic patients.

    Science.gov (United States)

    von Wagner, Christian; Smith, Samuel; Halligan, Steve; Ghanouni, Alex; Power, Emily; Lilford, Richard J; Morton, Dion; Dadswell, Edward; Atkin, Wendy; Wardle, Jane

    2011-10-01

    To determine patient acceptability of barium enema (BE) or CT colonography (CTC). After ethical approval, 921 consenting patients with symptoms suggestive of colorectal cancer who had been randomly assigned and completed either BE (N = 606) or CTC (N = 315) received a questionnaire to assess experience of the clinical episode including bowel preparation, procedure and complications. Satisfaction, worry and physical discomfort were assessed using an adapted version of a validated acceptability scale. Non-parametric methods assessed differences between the randomised tests and the effect of patient characteristics. Patients undergoing BE were significantly less satisfied (median 61, interquartile range [IQR] 54-67 vs. median 64, IQR 56-69; p = 0.003) and experienced more physical discomfort (median 40, IQR 29-52 vs. median 35.5, IQR 25-47; p < 0.001) than those undergoing CTC. Post-test, BE patients were significantly more likely to experience 'abdominal pain/cramps' (68% vs. 57%; p = 0.007), 'soreness' (57% vs. 37%; p < 0.001), 'nausea/vomiting' (16% vs. 8%; p = 0.009), 'soiling' (31% vs. 23%; p = 0.034) and 'wind' (92% vs. 84%; p = 0.001) and in the case of 'wind' to also rate it as severe (27% vs. 15%; p < 0.001). CTC is associated with significant improvements in patient experience. These data support the case for CTC to replace BE.

  1. Patient acceptability of CT colonography compared with double contrast barium enema: results from a multicentre randomised controlled trial of symptomatic patients

    International Nuclear Information System (INIS)

    Wagner, Christian von; Smith, Samuel; Ghanouni, Alex; Power, Emily; Wardle, Jane; Halligan, Steve; Lilford, Richard J.; Morton, Dion; Dadswell, Edward; Atkin, Wendy

    2011-01-01

    To determine patient acceptability of barium enema (BE) or CT colonography (CTC). After ethical approval, 921 consenting patients with symptoms suggestive of colorectal cancer who had been randomly assigned and completed either BE (N = 606) or CTC (N = 315) received a questionnaire to assess experience of the clinical episode including bowel preparation, procedure and complications. Satisfaction, worry and physical discomfort were assessed using an adapted version of a validated acceptability scale. Non-parametric methods assessed differences between the randomised tests and the effect of patient characteristics. Patients undergoing BE were significantly less satisfied (median 61, interquartile range [IQR] 54-67 vs. median 64, IQR 56-69; p = 0.003) and experienced more physical discomfort (median 40, IQR 29-52 vs. median 35.5, IQR 25-47; p < 0.001) than those undergoing CTC. Post-test, BE patients were significantly more likely to experience 'abdominal pain/cramps' (68% vs. 57%; p = 0.007), 'soreness' (57% vs. 37%; p < 0.001), 'nausea/vomiting' (16% vs. 8%; p = 0.009), 'soiling' (31% vs. 23%; p = 0.034) and 'wind' (92% vs. 84%; p = 0.001) and in the case of 'wind' to also rate it as severe (27% vs. 15%; p < 0.001). CTC is associated with significant improvements in patient experience. These data support the case for CTC to replace BE. (orig.)

  2. Patient acceptability of CT colonography compared with double contrast barium enema: results from a multicentre randomised controlled trial of symptomatic patients

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Christian von; Smith, Samuel; Ghanouni, Alex; Power, Emily; Wardle, Jane [University College London, Department of Epidemiology and Public Health, London (United Kingdom); Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); University College Hospital, Centre for Medical Imaging, London (United Kingdom); Lilford, Richard J. [Birmingham University, Department of Epidemiology, Birmingham (United Kingdom); Morton, Dion [Birmingham University, Department of Surgery, Birmingham (United Kingdom); Dadswell, Edward; Atkin, Wendy [Imperial College London, Department of Surgery and Cancer, London (United Kingdom)

    2011-10-15

    To determine patient acceptability of barium enema (BE) or CT colonography (CTC). After ethical approval, 921 consenting patients with symptoms suggestive of colorectal cancer who had been randomly assigned and completed either BE (N = 606) or CTC (N = 315) received a questionnaire to assess experience of the clinical episode including bowel preparation, procedure and complications. Satisfaction, worry and physical discomfort were assessed using an adapted version of a validated acceptability scale. Non-parametric methods assessed differences between the randomised tests and the effect of patient characteristics. Patients undergoing BE were significantly less satisfied (median 61, interquartile range [IQR] 54-67 vs. median 64, IQR 56-69; p = 0.003) and experienced more physical discomfort (median 40, IQR 29-52 vs. median 35.5, IQR 25-47; p < 0.001) than those undergoing CTC. Post-test, BE patients were significantly more likely to experience 'abdominal pain/cramps' (68% vs. 57%; p = 0.007), 'soreness' (57% vs. 37%; p < 0.001), 'nausea/vomiting' (16% vs. 8%; p = 0.009), 'soiling' (31% vs. 23%; p = 0.034) and 'wind' (92% vs. 84%; p = 0.001) and in the case of 'wind' to also rate it as severe (27% vs. 15%; p < 0.001). CTC is associated with significant improvements in patient experience. These data support the case for CTC to replace BE. (orig.)

  3. Intra-individual comparison of magnesium citrate and sodium phosphate for bowel preparation at CT colonography: automated volumetric analysis of residual fluid for quality assessment.

    Science.gov (United States)

    Bannas, P; Bakke, J; Munoz del Rio, A; Pickhardt, P J

    2014-11-01

    To perform an objective, intra-individual comparison of residual colonic fluid volume and attenuation associated with the current front-line laxative magnesium citrate (MgC) versus the former front-line laxative sodium phosphate (NaP) at CT colonography (CTC). This retrospective Health Insurance and Portability and Accountability Act-compliant study had institutional review board approval; informed consent was waived. The study cohort included 250 asymptomatic adults (mean age at index 56.1 years; 124 male/126 female) who underwent CTC screening twice over a 5 year interval. Colon catharsis at initial and follow-up screening employed single-dose NaP and double-dose MgC, respectively, allowing for intra-patient comparison. Automated volumetric analysis of residual colonic fluid volume and attenuation was performed on all 500 CTC studies. Colonic fluid volume volumetric analysis suggests that the replacement of NaP by MgC as the front-line laxative for CTC has not compromised overall examination quality. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  4. 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.)

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

    International Nuclear Information System (INIS)

    Plumb, Andrew A.; Pendse, Douglas A.; Taylor, Stuart A.; Halligan, Steve; Mallett, Susan

    2014-01-01

    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.)

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

    International Nuclear Information System (INIS)

    Hjern, F.; Jonas, E.; Holmstroem, B.; Josephson, T.; Mellgren, A.; Johansson, C.

    2007-01-01

    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 (κ = 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

  7. 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.

  8. An adaptive approach to centerline extraction for CT colonography using MAP-EM segmentation and distance field

    Science.gov (United States)

    Peng, Hao; Li, Lihong C.; Wang, Huafeng; Han, Hao; Pickhardt, Perry J.; Liang, Zhengrong

    2014-03-01

    In this paper, we present an adaptive approach for fully automatic centerline extraction and small intestine removal based on partial volume (PV) image segmentation and distance field modeling. Computed tomographic colonography (CTC) volume image is first segmented for the colon wall mucosa layer, which represents the PV effect around the colon wall. Then centerline extraction is performed in the presence of colon collapse and small intestine touch by the use of distance field within the segmented PV mucosa layer, where centerline breakings due to collapse are recovered and centerline branches due to small intestine tough are removed. Experimental results from 24 patient CTC scans with small intestine touch rendered 100% removal of the touch, while only 16 out of the 24 could be done by the well-known isolated component method. Our voxel-by-voxel marking strategy in the automated procedure preserves the topology and validity of the colon structure. The marked inner and outer boundaries on cleansed colon are very close to those labeled by the experts. Experimental results demonstrated the robustness and efficiency of the presented adaptive approach for CTC utility.

  9. Adverse events during CT colonography for screening, diagnosis and preoperative staging of colorectal cancer: a Japanese national survey

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Koichi [Japanese Society of Gastrointestinal Cancer Screening, Committee for Quality Assessment of Colorectal Cancer Screening, Tokyo (Japan); Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); National Cancer Centre, Division of Screening Technology, Centre for Public Health Sciences, Tokyo (Japan); Takabayashi, Ken [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); National Cancer Centre, Division of Screening Technology, Centre for Public Health Sciences, Tokyo (Japan); Hokkaido Gastroenterology Hospital, Department of Radiology, Sapporo (Japan); Yasuda, Takaaki [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); National Cancer Centre, Division of Screening Technology, Centre for Public Health Sciences, Tokyo (Japan); Nagasaki Kamigoto Hospital, Department of Radiology, Nagasaki (Japan); Hirayama, Michiaki [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Tonan Hospital, Department of Gastroenterology, Sapporo (Japan); Endo, Shungo [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Fukushima Medical University, Department of Coloproctology, Aizu Medical Centre, Aizu-Wakamatsu, Fukushima (Japan); Nozaki, Ryoichi [Japanese Society of Gastrointestinal Cancer Screening, Committee for Quality Assessment of Colorectal Cancer Screening, Tokyo (Japan); Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Takano Hospital, Coloproctology Centre, Kumamoto (Japan); Shimada, Takenobu [Japanese Society of Gastrointestinal Cancer Screening, Committee for Quality Assessment of Colorectal Cancer Screening, Tokyo (Japan); Cancer Detection Centre of the Miyagi Cancer Society, Sendai, Miyagi (Japan); Kanazawa, Hidenori [National Cancer Centre, Division of Screening Technology, Centre for Public Health Sciences, Tokyo (Japan); Jichi Medical University, Department of Radiology, Shimotsuke, Tochigi (Japan); Fujiwara, Masanori [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Kameda Medical Centre Makuhari, Radiology Section, Mihama-ku, Chiba (Japan); Shimizu, Norihito [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Matsuoka Clinic, Radiology Section, Nara (Japan); Iwatsuki, Tatema [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Matsuda Hospital, Radiology Section, Hamamatsu, Shizuoka (Japan); Iwano, Teruaki [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Tokushima Kensei Hospital, Radiology Section, Tokushima (Japan); Saito, Hiroshi [Japanese Society of Gastrointestinal Cancer Screening, Committee for Quality Assessment of Colorectal Cancer Screening, Tokyo (Japan); National Cancer Centre, Division of Screening Assessment and Management, Centre for Public Health Sciences, Tokyo (Japan)

    2017-12-15

    To retrospectively evaluate the frequencies and magnitudes of adverse events associated with computed tomographic colonography (CTC) for screening, diagnosis and preoperative staging of colorectal cancer. A Japanese national survey on CTC was administered by use of an online survey tool in the form of a questionnaire. The questions covered mortality, colorectal perforation, vasovagal reaction, total number of examinations, and examination procedures. The survey data was collated and raw frequencies were determined. Fisher's exact test was used to determine differences in event rates between groups. At 431 institutions, 147,439 CTC examinations were performed. No deaths were reported. Colorectal perforations occurred in 0.014% (21/147,439): 0.003% (1/29,823) in screening, 0.014% (13/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging. The perforation risk was significantly lower in screening than in preoperative staging CTC procedures (p = 0.028). Eighty-one per cent of perforation cases (17/21) did not require emergency surgery. Vasovagal reaction occurred in 0.081% (120/147,439): 0.111% (33/29,823) in screening, 0.088% (80/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging. The risk of colorectal perforation and vasovagal reaction in CTC is low. The frequency of colorectal perforation associated with CTC is least in the screening group and greatest in the preoperative-staging group. (orig.)

  10. Evaluating patients' preferences for type of bowel preparation prior to screening CT colonography: Convenience and comfort versus sensitivity and specificity

    International Nuclear Information System (INIS)

    Ghanouni, A.; Halligan, S.; Taylor, S.A.; Boone, D.; Plumb, A.; Wardle, J.; Wagner, C. von

    2013-01-01

    Aims: To explore the relative value patients place on comfort and convenience versus test sensitivity and specificity in the context of computed tomographic colonography (CTC) screening. Materials and methods: Twenty semi-structured interviews were carried out with patients attending hospital for radiological tests unrelated to CTC. Preferences for CTC with different types of bowel preparation for CTC screening were examined and interviews were analysed thematically. The discussion guide included separate sections on CTC, bowel preparation methods (non-, reduced- and full-laxative), and sensitivity and specificity. Patients were given information on each topic in turn and asked about their views and preferences during each section. Results: Following information about the test, patients' attitudes towards CTC were positive. Following information on bowel preparation, full-laxative purgation was anticipated to cause more adverse physical and lifestyle effects than using reduced- or non-laxative preparation. However, stated preferences were approximately equally divided, largely due to patients anticipating that non-laxative preparations would reduce test accuracy (because the bowel was not thoroughly cleansed). Following information on sensitivity and specificity (which supported patients' expectations), the predominant stated preference was for full-laxative preparation. Conclusions: Patients are likely to value test sensitivity and specificity over a more comfortable and convenient preparation. Future research should test this hypothesis on a larger sample

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

    International Nuclear Information System (INIS)

    Kim, S.H.; Choi, B.I.; Han, J.K.; Lee, J.M.; Eun, H.W.; Lee, J.Y.; Lee, K.H.; Han, C.J.; Choi, Y.H.; Shin, K.-S.

    2006-01-01

    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). 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

  12. Double Colorectal Cancer Only Diagnosed by Computed Tomographic Colonography

    Directory of Open Access Journals (Sweden)

    Koichi Nagata

    2008-02-01

    Full Text Available A 58-year-old woman presented to her physician with rectal bleeding and intermittent diarrhea. Optical colonoscopy revealed a bulky tumor which was diagnosed as rectal cancer. She was referred to our institution for further evaluation and treatment. Slim optical colonoscopy showed an obstructive cancer in the rectosigmoid junction and no information of the proximal side of the obstruction. The patient then underwent computed tomographic (CT colonography for further evaluation of the proximal side. Three-dimensional endoluminal ‘fly-through’ images revealed another protruded lesion in the proximal side of the obstruction. Diagnosis of synchronous double cancer was made by CT colonography. This CT data was not only used to create three-dimensional images but also to decide on a preoperative clinical staging. Laparoscopy-assisted high anterior resection was performed and T3 rectal cancer and T1 sigmoid colon cancer were confirmed in the resected specimen. Follow-up optical colonoscopy revealed no other tumors. CT colonography has recently become a popular preoperative examination tool with significant improvement in quality of image due to a rapid progress in computer technology. CT colonography correctly showed synchronous double cancer in our case and provided crucial information for planning surgery. We recommend that CT colonography should be used for evaluating the proximal side of obstructive colorectal cancer.

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

    International Nuclear Information System (INIS)

    Lubner, Meghan G.; Pooler, B.D.; Kitchin, Douglas R.; Kim, David H.; Munoz del Rio, Alejandro; Pickhardt, Perry J.; Tang, Jie; Li, Ke; Chen, Guang-Hong

    2015-01-01

    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 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 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.)

  14. 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

  15. Intra-individual comparison of magnesium citrate and sodium phosphate for bowel preparation at CT colonography: Automated volumetric analysis of residual fluid for quality assessment

    International Nuclear Information System (INIS)

    Bannas, P.; Bakke, J.; Munoz del Rio, A.; Pickhardt, P.J.

    2014-01-01

    Aim: To perform an objective, intra-individual comparison of residual colonic fluid volume and attenuation associated with the current front-line laxative magnesium citrate (MgC) versus the former front-line laxative sodium phosphate (NaP) at CT colonography (CTC). Materials and methods: This retrospective Health Insurance and Portability and Accountability Act-compliant study had institutional review board approval; informed consent was waived. The study cohort included 250 asymptomatic adults (mean age at index 56.1 years; 124 male/126 female) who underwent CTC screening twice over a 5 year interval. Colon catharsis at initial and follow-up screening employed single-dose NaP and double-dose MgC, respectively, allowing for intra-patient comparison. Automated volumetric analysis of residual colonic fluid volume and attenuation was performed on all 500 CTC studies. Colonic fluid volume <200 ml and mean attenuation between 300–900 HU were considered optimal. Paired t-test and McNemar's test were used to compare differences. Results: Residual fluid volumes <200 ml were recorded in 192 examinations (76.8%) following MgC and in 204 examinations (81.6%) following NaP (p = 0.23). The mean total residual fluid volume was 155 ± 114 ml for MgC and 143 ± 100 ml for NaP (p = 0.01). The attenuation range of 300–900 HU was significantly more frequent for MgC (n = 220, 88%) than for NaP (n = 127, 50.8%; p < 0.001). Mean fluid attenuation was significantly lower for MgC (700 ± 165 HU) than for NaP (878 ± 155 HU; p < 0.001). Concomitant presence of both optimal fluid volume and attenuation was significantly more frequent for MgC 65.2% than for NaP (38%; p < 0.001). Conclusions: Objective intra-individual comparison using automated volumetric analysis suggests that the replacement of NaP by MgC as the front-line laxative for CTC has not compromised overall examination quality. - Highlights: • Automated volumetric analysis provides

  16. Massive-training artificial neural network coupled with Laplacian-eigenfunction-based dimensionality reduction for computer-aided detection of polyps in CT colonography.

    Science.gov (United States)

    Suzuki, Kenji; Zhang, Jun; Xu, Jianwu

    2010-11-01

    A major challenge in the current computer-aided detection (CAD) of polyps in CT colonography (CTC) is to reduce the number of false-positive (FP) detections while maintaining a high sensitivity level. A pattern-recognition technique based on the use of an artificial neural network (ANN) as a filter, which is called a massive-training ANN (MTANN), has been developed recently for this purpose. The MTANN is trained with a massive number of subvolumes extracted from input volumes together with the teaching volumes containing the distribution for the "likelihood of being a polyp;" hence the term "massive training." Because of the large number of subvolumes and the high dimensionality of voxels in each input subvolume, the training of an MTANN is time-consuming. In order to solve this time issue and make an MTANN work more efficiently, we propose here a dimension reduction method for an MTANN by using Laplacian eigenfunctions (LAPs), denoted as LAP-MTANN. Instead of input voxels, the LAP-MTANN uses the dependence structures of input voxels to compute the selected LAPs of the input voxels from each input subvolume and thus reduces the dimensions of the input vector to the MTANN. Our database consisted of 246 CTC datasets obtained from 123 patients, each of whom was scanned in both supine and prone positions. Seventeen patients had 29 polyps, 15 of which were 5-9 mm and 14 were 10-25 mm in size. We divided our database into a training set and a test set. The training set included 10 polyps in 10 patients and 20 negative patients. The test set had 93 patients including 19 polyps in seven patients and 86 negative patients. To investigate the basic properties of a LAP-MTANN, we trained the LAP-MTANN with actual polyps and a single source of FPs, which were rectal tubes. We applied the trained LAP-MTANN to simulated polyps and rectal tubes. The results showed that the performance of LAP-MTANNs with 20 LAPs was advantageous over that of the original MTANN with 171 inputs. To

  17. Massive-Training Artificial Neural Network Coupled With Laplacian-Eigenfunction-Based Dimensionality Reduction for Computer-Aided Detection of Polyps in CT Colonography

    Science.gov (United States)

    Suzuki, Kenji; Zhang, Jun; Xu, Jianwu

    2014-01-01

    A major challenge in the current computer-aided detection (CAD) of polyps in CT colonography (CTC) is to reduce the number of false-positive (FP) detections while maintaining a high sensitivity level. A pattern-recognition technique based on the use of an artificial neural network (ANN) as a filter, which is called a massive-training ANN (MTANN), has been developed recently for this purpose. The MTANN is trained with a massive number of subvolumes extracted from input volumes together with the teaching volumes containing the distribution for the “likelihood of being a polyp;” hence the term “massive training.” Because of the large number of subvolumes and the high dimensionality of voxels in each input subvolume, the training of an MTANN is time-consuming. In order to solve this time issue and make an MTANN work more efficiently, we propose here a dimension reduction method for an MTANN by using Laplacian eigenfunctions (LAPs), denoted as LAP-MTANN. Instead of input voxels, the LAP-MTANN uses the dependence structures of input voxels to compute the selected LAPs of the input voxels from each input subvolume and thus reduces the dimensions of the input vector to the MTANN. Our database consisted of 246 CTC datasets obtained from 123 patients, each of whom was scanned in both supine and prone positions. Seventeen patients had 29 polyps, 15 of which were 5–9 mm and 14 were 10–25 mm in size. We divided our database into a training set and a test set. The training set included 10 polyps in 10 patients and 20 negative patients. The test set had 93 patients including 19 polyps in seven patients and 86 negative patients. To investigate the basic properties of a LAP-MTANN, we trained the LAP-MTANN with actual polyps and a single source of FPs, which were rectal tubes. We applied the trained LAP-MTANN to simulated polyps and rectal tubes. The results showed that the performance of LAP-MTANNs with 20 LAPs was advantageous over that of the original MTANN with 171

  18. Your Radiologist Explains CT Colonography

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  5. Audit of the introduction of CT colonography for detection of colorectal carcinoma in a non-academic environment and its implications for the national bowel cancer screening programme

    International Nuclear Information System (INIS)

    Thomas, S.; Atchley, J.; Higginson, A.

    2009-01-01

    Aim: To compare the sensitivity of double-contrast barium enema (DCBE) with computed tomography colonography (CTC) to determine whether CTC is superior for the detection of colorectal cancer (CRC) locally, and to compare the results to those of a national barium enema audit. Materials and methods: All patients undergoing diagnostic DCBE or CTC between January 2003 and December 2005 were identified from the picture archiving communication system (PACS). Patients with a confirmed diagnosis of CRC were identified from the local cancer registry. Patients who were not diagnosed as having CRC on imaging were assumed true negatives if they were not listed in the cancer registry by December 2007, giving a minimum of 2 years follow-up. DCBE and CTC reports of all patients with CRC were analysed, and cancer detection was considered to have occurred (positive test result) if the report stated the definite presence of CRC or possible CRC requiring further investigation. Results: 2520 DCBEs and 604 CTCs were included. Twenty-one of 33 patients with CRC were detected using DCBE (incidence 1.31%, sensitivity 63.7%). Thirty-two of 33 patients with CRC were -detected using CTC (incidence 5.46%, sensitivity 97.7%). Conclusion: CTC is more sensitive for the detection of CRC, and its introduction in a district general hospital is justified. However, there has been a consequent decline in DCBE sensitivity, which, if reflected nationally, suggests CTC is the preferential screening test for CRC

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

    International Nuclear Information System (INIS)

    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

  7. MR colonography: current status

    International Nuclear Information System (INIS)

    Lauenstein, Thomas C.

    2006-01-01

    Magnetic resonance colonography (MRC) has gained access into clinical routine as a means for the assessment of the large bowel. There are widely accepted indications for MRC, especially in patients with incomplete conventional colonoscopy. Furthermore, virtual MRC is more and more propagated as a screening tool, with advantages especially inherent to the non-invasive character of this procedure and the lack of ionizing radiation exposition. Beyond a sufficiently high diagnostic accuracy, outstanding patient acceptance is a major advantage of MRC as a diagnostic modality. This review article describes indications, techniques and clinical outcome of current MRC approaches. Furthermore, the impact of fecal tagging concepts is discussed. (orig.)

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    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. (orig.)

  9. Contrast-enhanced computed tomographic colonography in the follow-up of colorectal cancer patients: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Laghi, Andrea; Iannaccone, Riccardo; Carbone, Iacopo; Piacentini, Francesca; Passariello, Roberto [Department of Radiology, University of Rome ' ' La Sapienza' ' , Policlinico Umberto I, Rome (Italy); Bria, Emilio; Trasatti, Luciana; Lauro, Salvatore; Vecchione, Aldo [Department of Medical Oncology, Policlinico S. Andrea (Italy)

    2003-04-01

    The aim of our study was to assess whether contrast-enhanced CT colonography is a feasible alternative to both conventional colonoscopy and liver ultrasonography in the follow-up program of colorectal cancer patients. Thirty-five patients, surgically treated for colorectal cancer, underwent a follow-up program that included physical examination, carcinoembryonic antigen serum assay, conventional colonoscopy, liver ultrasonography, and chest X-ray. For these patients, we added a yearly contrast-enhanced CT colonography. All CT examinations were performed with a high-resolution protocol using a multidetector spiral CT scanner (Siemens, Erlangen, Germany) prior to and after the administration of 130 ml of i.v. contrast material. Images were directly analyzed on a dedicated workstation by two radiologists to determine colonic evaluation, visualization of colonic anastomosis, presence of polyps, and extra-colonic findings. Colonic evaluation was judged as optimal in 91.7% of all colonic segments. All mechanical surgical anastomoses were visualized with CT colonography. There was no evidence of anastomotic recurrence. Seven polyps were detected in five different patients with CT colonography, with two false-positive and no false-negative examinations. Three liver metastases and two basal pulmonary nodules were also identified. Contrast-enhanced CT colonography is a feasible alternative to both conventional colonoscopy and liver ultrasonography in the follow-up of patients operated on for colorectal cancer. (orig.)

  10. Contrast-enhanced computed tomographic colonography in the follow-up of colorectal cancer patients: a feasibility study

    International Nuclear Information System (INIS)

    Laghi, Andrea; Iannaccone, Riccardo; Carbone, Iacopo; Piacentini, Francesca; Passariello, Roberto; Bria, Emilio; Trasatti, Luciana; Lauro, Salvatore; Vecchione, Aldo

    2003-01-01

    The aim of our study was to assess whether contrast-enhanced CT colonography is a feasible alternative to both conventional colonoscopy and liver ultrasonography in the follow-up program of colorectal cancer patients. Thirty-five patients, surgically treated for colorectal cancer, underwent a follow-up program that included physical examination, carcinoembryonic antigen serum assay, conventional colonoscopy, liver ultrasonography, and chest X-ray. For these patients, we added a yearly contrast-enhanced CT colonography. All CT examinations were performed with a high-resolution protocol using a multidetector spiral CT scanner (Siemens, Erlangen, Germany) prior to and after the administration of 130 ml of i.v. contrast material. Images were directly analyzed on a dedicated workstation by two radiologists to determine colonic evaluation, visualization of colonic anastomosis, presence of polyps, and extra-colonic findings. Colonic evaluation was judged as optimal in 91.7% of all colonic segments. All mechanical surgical anastomoses were visualized with CT colonography. There was no evidence of anastomotic recurrence. Seven polyps were detected in five different patients with CT colonography, with two false-positive and no false-negative examinations. Three liver metastases and two basal pulmonary nodules were also identified. Contrast-enhanced CT colonography is a feasible alternative to both conventional colonoscopy and liver ultrasonography in the follow-up of patients operated on for colorectal cancer. (orig.)

  11. Test-positive rate at CT colonography is increased by rectal bleeding and/or unexplained weight loss, unlike other common gastrointestinal symptoms

    International Nuclear Information System (INIS)

    Hock, D.; Materne, R.; Ouhadi, R.; Mancini, I.; Aouachria, S.A.; Nchimi, A.

    2015-01-01

    We evaluated the rate of significant colonic and extra-colonic abnormalities at computed tomography colonography (CTC), according to symptoms and age. We retrospectively evaluated 7361 consecutive average-risk subjects (3073 males, average age: 60.3 ± 13.9; range 18–96 years) for colorectal cancer (CRC) who underwent CTC. They were divided into three groups according to clinical symptoms: 1343 asymptomatic individuals (group A), 899 patients with at least one “alarm” symptom for CRC, including rectal bleeding and unexplained weight loss (group C), and 5119 subjects with other gastrointestinal symptoms (group B). Diagnostic and test-positive rates of CTC were established using optical colonoscopy (OC) and/or surgery as reference standard. In addition, clinically significant extra-colonic findings were noted. 903 out of 7361 (12%, 95% confidence interval (CI) 0.11–0.13) subjects had at least one clinically significant colonic finding at CTC. CTC true positive fraction and false positive fraction were respectively 637/642 (99.2%, 95%CI 0.98–0.99) and 55/692 (7.95%, 95%CI 0.05–0.09). The pooled test-positive rate in group C (138/689, 20.0%, 95%CI 0.17–0.23) was significantly higher than in both groups A (79/1343, 5.9%, 95%CI 0.04–0.07) and B (420/5329, 7.5%, 95%CI 0.07–0.08) (p < 0.001). Aging and male gender were associated to a higher test positive rate. The rate of clinically significant extra-colonic findings was significantly higher in group C (44/689, 6.4%, 95%CI 0.04–0.08) versus groups A (26/1343, 1.9%, 95%CI 0.01–0.02) and B (64/5329, 1.2%, 95%CI 0.01–0.02) (p < 0.001). Both test-positive and significant extra-colonic finding rates at CTC are significantly increased in the presence of “alarm” gastrointestinal symptoms especially in older patients

  12. 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

    Science.gov (United States)

    Kim, Min Ju; Lee, Seung Soo; Byeon, Jeong-Sik; Choi, Eugene K.; Kim, Jung Hoon; Kim, Yeoung Nam; Kim, Ah Young; Ha, Hyun Kwon

    2009-01-01

    Objective 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. Materials and Methods 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. Results 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). Conclusion 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

  13. Multidetector CT of the colon

    International Nuclear Information System (INIS)

    Luboldt, W.; Hoepffner, N.; Holzer, K.

    2003-01-01

    Multidetector technology, enabling faster imaging, higher spatial resolution and reduction in radiation dose, increases the role of CT in colonic diagnostic. The higher spatial resolution in the z-direction also changes the way to analyze the images. Instead of reading axial sections, now the colon can be systematically assessed in 3D by scrolling through multiplanar reconstructions or in CT colonography by virtual endoscopy. With ongoing improvements in computer-aided diagnosis CT colonography becomes an alternative to fiberoptic colonocopy for screening (http://www.multiorganscreening.org). In this article we propose a CT examination protocol for the colon, describe the typical imaging findings of different colonic diseases, and summarize the current status of CT colonography. (orig.)

  14. CT Colonography - competition or complementary?: guest editorial ...

    African Journals Online (AJOL)

    South African Gastroenterology Review. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 2, No 2 (2004) >. Log in or Register to get access to full text downloads.

  15. CT Colonography - competition or complementary?: guest editorial ...

    African Journals Online (AJOL)

    South African Gastroenterology Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 2, No 2 (2004) >. Log in or Register to get access to full text downloads.

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

    DEFF Research Database (Denmark)

    Achiam, M P; Løgager, V; Chabanova, E

    2010-01-01

    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 ex......-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....

  17. 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

  18. Computer tomography colonography participation and yield in patients under surveillance for 6-9 mm polyps in a population-based screening trial

    NARCIS (Netherlands)

    Tutein Nolthenius, Charlotte J.; Boellaard, Thierry N.; de Haan, Margriet C.; Nio, C. Yung; Thomeer, Maarten G. J.; Bipat, Shandra; Montauban van Swijndregt, Alexander D.; van de Vijver, Marc J.; Biermann, Katharina; Kuipers, Ernst J.; Dekker, Evelien; Stoker, Jaap

    2016-01-01

    Surveillance CT colonography (CTC) is a viable option for 6-9 mm polyps at CTC screening for colorectal cancer. We established participation and diagnostic yield of surveillance and determined overall yield of CTC screening. In an invitational CTC screening trial 82 of 982 participants harboured 6-9

  19. Colon dissection: a new three-dimensional reconstruction tool for computed tomography colonography

    International Nuclear Information System (INIS)

    Roettgen, R.; Fischbach, F.; Plotkin, M.; Herzog, H.; Freund, T.; Schroeder, R. J.; Felix, R.

    2005-01-01

    Purpose: To improve the sensitivity of computed tomography (CT) colonography in the detection of polyps by comparing the 3D reconstruction tool 'colon dissection' and endoluminal view (virtual colonoscopy) with axial 2D reconstructions. Material and Methods: Forty-eight patients (22 M, 26 F, mean age 57±21) were studied after intra-anal air insufflation in the supine and prone positions using a 16-slice helical CT (16x0.625 mm, pitch 1.7; detector rotation time 0.5 s; 160 mAs und 120 kV) and conventional colonoscopy. Two radiologists blinded to the results of the conventional colonoscopy analyzed the 3D reconstruction in virtual-endoscopy mode, in colon-dissection mode, and axial 2D slices. Results: Conventional colonoscopy revealed a total of 35 polyps in 15 patients; 33 polyps were disclosed by CT methods. Sensitivity and specificity for detecting colon polyps were 94% and 94%, respectively, when using the 'colon dissection', 89% and 94% when using 'virtual endoscopy', and 62% and 100% when using axial 2D reconstruction. Sensitivity in relation to the diameter of colon polyps with 'colon dissection', 'virtual colonoscopy', and axial 2D-slices was: polyps with a diameter >5.0 mm, 100%, 100%, and 71%, respectively; polyps with a diameter of between 3 and 4.9 mm, 92%, 85%, and 46%; and polyps with a diameter <3 mm, 89%, 78%, and 56%. The difference between 'virtual endoscopy' and 'colon dissection' in diagnosing polyps up to 4.9 mm in diameter was statistically significant. Conclusion: 3D reconstruction software 'colon dissection' improves sensitivity of CT colonography compared with the endoluminal view

  20. Computed tomographic colonography (CTC); colorectal cancer diagnosis with CTC in an Auckland population.

    Science.gov (United States)

    Moore, Helen; Dodd, Nicholas

    2013-10-01

    To determine the sensitivity of computed tomographic colonography (CTC) in the detection of colorectal cancer in our population and evaluate the reasons why these lesions may be missed on CTC. All patients who underwent CTC in the 65-month period from 1 January 2004 to 1 July 2009 were included in the analysis. Demographic data and CTC findings were recorded, according to the CT Colonography Reporting and Data System. Data were cross-matched with the National Cancer Registry results for colorectal cancer cases between 1 January 2004 and 1 October 2009, 3 months longer to include any delayed diagnoses. There were 2026 consecutive CTC patients, comprising 52.6% female, average age of 60 years; range 19-87. Approximately 84% were symptomatic. There were 45 confirmed colorectal cancers among this patient group in the National Cancer Registry during the relevant time period compared with 43 suspected cancers on CTC, giving a miss rate of 2 of 45, or 4.4%. The sensitivity of 95% for CTC in the detection of colorectal cancer compares favourably with the published national and international data. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  1. Computed tomographic colonography: colonic and extracolonic findings in an Auckland population.

    Science.gov (United States)

    Moore, Helen; Dodd, Nicholas

    2012-06-08

    To determine the nature and prevalence of colonic and extracolonic findings in our population. All patients who underwent computed tomographic colonography (CTC) in the 72-month period from 1 January 2004 to 1 January 2010 were included in the analysis. Demographic data and CTC findings were recorded, according to the CT colonography reporting and data system (CRADS). There were 2152 consecutive CTC patients; comprising 52.6% female, average age of 60 years; range 19-87. Approximately 84% were symptomatic. CRADS: Colonic findings: 99/2152 patients (4.6%) were C2 category (had 1 or 2 polyps of 6-9 mm). 77/2152 (3.6%) patients were C3 category (>9 mm polyp or >2 polyps of 6-9 mm). 55/2152 (2.5%) were C4 category (possible cancer). This comprises a total potential colonoscopy/surgery referral rate of 10.7%. Extracolonic findings: The majority were normal or clinically unimportant findings. 178/2152 (8.3%) had potentially significant extracolonic findings. Our CTC population is largely symptomatic, and there is a referral rate from CTC to colonoscopy, surgery or surveillance of 10.7%. This is similar to other NZ data and international studies. The 8.3% rate of potentially significant extracolonic findings is at the lower end of the reported range.

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

    African Journals Online (AJOL)

    2017-02-28

    Feb 28, 2017 ... The longitudinal taenia coli end at the rectosigmoid junction and continue only as a smooth muscle layer in the rectum.10 The three valves of Houston (superior, middle and inferior) encircle about a third to a half of the rectal circumference.11 In a CTC study, the middle valve may serve as a landmark.

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

    African Journals Online (AJOL)

    2017-02-28

    Feb 28, 2017 ... FIGURE 9: (a) 3D endoluminal view showing artefacts (black arrows) obscuring visualisation of the rectum; (b) 2D axial of the same patient shows streak artefacts limiting visualisation of colon (red arrow). This is a typical example of artefacts caused by hip prostheses; (c) 3D view shows 'black hole' artefact.

  4. Technical quality of CT colonography in relation with diverticular disease

    International Nuclear Information System (INIS)

    Flor, Nicola; Rigamonti, Paolo; Di Leo, Giovanni; Ceretti, Andrea Pisani; Opocher, Enrico; Sardanelli, Francesco; Cornalba, Gian Paolo

    2012-01-01

    Objective: The aim of the study is to explore how the technical quality of the examination was affected by diverticular disease. Materials and methods: We retrospectively evaluated a consecutive series of 78 subjects who underwent CTC for screening (n = 58) or staging (n = 20) colorectal cancer, 38 of them (49%) after an incomplete optical colonoscopy. Patients were administered a mild laxative and a iodinated contrast material for fecal tagging. We scored both the bowel preparation and the overall colon distension as poor, good, or optimal and measured the mean sigmoid colon diameter. We counted the number of diverticula and classified patients as having or not a severe diverticular disease (SDD). The number of the prompts of computer aided diagnosis (CAD) per patient was also considered. Mann–Whitney U and χ 2 tests were performed. Results: No CTC complications occurred. The bowel cleansing was poor in 8 (10%) patients, good in 29 (37%) and optimal in 41 (53%); colon distension was poor in 7 (9%) patients, good in 38 (49%), and optimal in 33 (42%). Fifty-four (69%) showed diverticula and 30 (38%) had an SDD. Bowel cleansing and distension were not significantly impaired by neither diverticula (p > 0.590) nor the SDD (p > 0.110). Mean sigmoid colon diameter was reduced in presence of diverticula (28 mm versus 23 mm, p = 0.009) or SDD (26 mm versus 22 mm, p = 0.016). The mean number of CAD prompts per patient was not significantly increased by the presence of SDD (p = 0.829). Conclusions: Bowel cleansing and distension at CTC were not influenced by the presence of diverticular disease.

  5. Preoperative evaluation of synchronous colorectal cancer using MR colonography

    DEFF Research Database (Denmark)

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

    2009-01-01

    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 it is noni...

  6. Bowel imaging: a reassessment. Pt. 2. CT and MRI; Bildgebende Diagnostik des Darms - eine Neubewertung. T. 2. CT und MRT

    Energy Technology Data Exchange (ETDEWEB)

    Hohl, C.; Muehlenbruch, G.; Schmidt, T.; Guenther, R.W. [Universitaetsklinikum RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik; Haage, P. [Universitaetsklinik Witten/Herdecke (Germany). HELIOS Klinikum Wuppertal, Klinik fuer Diagnostische und Interventionelle Radiologie

    2007-07-15

    This is the second part of a review of bowel imaging. While the first part addressed conventional X-ray techniques and ultrasonography, the second part discusses the diagnostic features of computed tomography (CT) and magnetic resonance imaging (MRI) including virtual colonography and PET-CT in the diagnosis of bowel disorders. Indications, performance and the diagnostic impact of the different methods are presented and discussed in the context of competitive methods such as (capsule-)endoscopy. (orig.)

  7. Predictors of Incomplete Optical Colonoscopy Using Computed Tomographic Colonography

    OpenAIRE

    Sachdeva, Reetika; Tsai, Salina D.; El Zein, Mohamad H.; Tieu, Alan A.; Abdelgelil, Ahmed; Besharati, Sepideh; Khashab, Mouen A.; Kalloo, Anthony N.; Kumbhari, Vivek

    2016-01-01

    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. Pat...

  8. A simple image processing approach for electronic cleansing in computed tomographic colonography

    Science.gov (United States)

    Yamamoto, S; Iinuma, G; Suzuki, M; Tanaka, T; Muramatsu, Y; Moriyama, N

    2009-01-01

    The prevalence of colon cancer has seen strong demand in screening for colorectal neoplasia, and this has drawn considerable attention to the technological advances in Computed Tomographic Colonography (CTC). With the assistance of an oral contrast agent, an imaging technique known as Electronic Cleansing (EC), can affect virtual cleaning of the computed tomography (CT) images, to remove fecal material that is tagged by the agent. Technical problems can arise with electronic cleansing however, when the air lumen causes distortions to the tagged regions which result in partial volume effects. Combining the simple image arithmetic of an electronic cleansing algorithm, with a vertical motion filter at the fluid level of the bowel, artifacts such as those caused by an air lumen are eliminated. Essentially, the filter becomes a vector for that carries the measurement of vertical motion to neutralise the artifact that is causing partial volume effects. Results demonstrate that despite its simplicity, this technique offers accuracy and is able to successfully maintain the normal intra-colonic structure, while supporting digital leaning of tagged residual material appearing on the colon wall. PMID:21611057

  9. Initial experience with computed tomographic colonography applied for noncolorectal cancerous conditions

    International Nuclear Information System (INIS)

    Ichikawa, Tamaki; Kawada, Shuichi; Hirata, Satoru; Ikeda, Shu; Sato, Yuuki; Imai, Yutaka

    2011-01-01

    The aim of this study was to asses retrospectively the performance of computed tomography colonography (CTC) for noncolorectal cancerous conditions. A total of 44 patients with non-colorectal cancerous conditions underwent CTC. We researched the indications for CTC or present illness and evaluated the CTC imaging findings. We assessed whether diagnosis by CTC reduced conventional colonoscopic examinations. A total of 47 examinations were performed in 44 patients. The indications for CTC or a present illness were as follows: 15 patients with impossible or incomplete colonoscopy, 7 with diverticular disease, 6 with malignancy (noncolorectal cancer), 6 with Crohn's disease, 4 suspected to have a submucosal tumor on colonoscopy, 2 with ischemic colitis, and 4 with various other diseases. Colonic findings were diagnosed on CTC in 36 examinations, and extracolonic findings were identified in 35 of 44 patients. In all, 17 patients had undergone colonoscopy previously, 9 (52.9%) of whom did not require further colonoscopy by CTC. Five patients underwent colonoscopy after CTC. The indications for CTC were varied for patients with noncolorectal cancerous conditions. CTC examinations could be performed safely. Unlike colonoscopy or CT without preparation, CTC revealed colonic and extracolonic findings and may reduce the indication of colonoscopy in patients with noncolorectal cancerous conditions. (author)

  10. Virtual Computed Tomography Colonography: Evaluation of 2D and Virtual 3D Image Quality of Sub-mSv Examinations Enabled by Third-generation Dual Source Scanner Featuring Tin Filtering.

    Science.gov (United States)

    Seuss, Hannes; Janka, Rolf; Hammon, Matthias; Cavallaro, Alexander; Uder, Michael; Dankerl, Peter

    2018-01-19

    To evaluate two- and three-dimensional (2D and 3D) image quality of sub-milliSievert (mSv) computed tomography (CT) colonography utilizing a third-generation dual source CT scanner featuring a tin filter. We retrospectively evaluated 26 consecutive patients who underwent third-generation dual source CT colonography, nine with the standard-dose clinical-scan protocol (SDP) and 17 with a low-dose protocol (LDP) featuring a tin filter. Radiation dose was evaluated by volume computed tomography dose index (CTDI vol ), dose length product (DLP), effective dose (E), and size-specific dose estimate. Objective image quality was evaluated utilizing signal-to-noise ratio (SNR) derived from standardized placed regions of interest on the transverse 2D images and the ratio of SNR/CTDI vol (normalized SNR). Two radiologists in consensus assessed subjective image quality of the virtual 3D images. There were no significant differences in subjective image quality (P = .661). All examinations were rated "excellent" or "good" for diagnostic confidence. The mean total for DLP/E was 143.4 ± 29.8 mGy/3.00 ± 0.40 mSv in the SDP and therefore significantly higher than in the LDP with 36.9 ± 8.7 mGy/0.75 ± 0.16 mSv (P source CT featuring a tin filter enables consistent sub-mSv colonography without substantially impairing image quality. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    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-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)

  13. 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)

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

    International Nuclear Information System (INIS)

    Achiam, M.P.; Logager, V.; Chabanova, E.; Thomsen, H.S.; Rosenberg, J.

    2010-01-01

    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.

  15. The diagnostic value of multiplanar reconstruction on MDCT colonography for the preoperative staging of colorectal cancer

    International Nuclear Information System (INIS)

    Jin, Kwang Nam; Kim, Se Hyung; Lee, Jae Young; Lee, Jeong Min; Han, Joon Koo; Choi, Byung Ihn; Shin, Kyung-Sook

    2006-01-01

    The purpose of this study was to determine whether multiplanar reconstruction (MPR) images can improve the accuracy of MDCT-based colorectal cancer preoperative staging by receiver-operating characteristic (ROC) analysis. Fifty-five patients with colorectal cancer underwent contrast-enhanced CT colonography using an 8- or 16-row scanner. Two separate interval reviews of the axial MDCT datasets with/without MPR images (coronal and sagittal) were performed independently by two radiologists blinded to both the colonoscopic and histopathologic results. At each review session, the radiologists were asked to determine the colorectal cancer TNM stage within the context of differentiating ≤T3 from T4, N0 from ≥N1 and M0 from M1 using a five-point confidence scale. The radiologists' performance for staging the colorectal cancer using axial CT datasets with/without MPR images was evaluated using ROC analysis. Sensitivities, specificities and interobserver agreement were assessed. When MPR images were added, significant improvement was achieved by both radiologists for differentiating N0 from ≥N1 in terms of both A Z (0.651 to 0.769; 0.573 to 0.713) and specificity (26.7 to 69.2%; 23.1 to 76.9%) (P 0.05), but a significant improvement in the specificity (70 to 90%; 80 to 92%) was achieved by one radiologist (P<0.05). In terms of the M staging, a significant improvement in the Az (0.844 to 0.996) was observed for the combined interpretation of the axial and MPR images by one radiologist (P<0.05). Furthermore, substantial or almost perfect interobserver agreement was achieved for all TNM stagings for the combined interpretations (κ=0.641-0.866), whereas only fair to substantial agreement was achieved for the axial images alone (κ=0.337-0.707). In conclusion, the combined interpretation of the axial and MPR MDCT images significantly improved the local staging of colorectal cancer compared with assessments based on axial images alone. (orig.)

  16. Diagnostic Performance of Computed Tomography Colonography and Colonoscopy: A Prospective and Validated Analysis of 231 Paired Examinations

    International Nuclear Information System (INIS)

    Arnesen, R.B.; Benzon, E. von; Adamsen, S.; Svendsen, L.B.; Raaschou, H.O.; Hart Hansen, O.

    2007-01-01

    Background: Detection of colorectal tumors with computed tomography colonography (CTC) is an alternative to conventional colonoscopy (CC), and clarification of the diagnostic performance is essential for cost-effective use of both technologies. Purpose: To evaluate the diagnostic performance of CTC compared with CC. Material and Methods: 231 consecutive CTCs were performed prior to same-day scheduled CC. The radiologist and endoscopists were blinded to each other's findings. Patients underwent a polyethylene glycol bowel preparation, and were scanned in prone and supine positions using a single-detector helical CT scanner and commercially available software for image analysis. Findings were validated (matched) in an unblinded comparison with video-recordings of the CCs and re-CCs in cases of doubt. Results: For patients with polyps 5 mm and 10 mm, the sensitivity was 69% (95% CI 58-80%) and 81% (68-94%), and the specificity was 91% (84-98%) and 98% (93-100%), respectively. For detection of polyps 5 mm and 10 mm, the sensitivity was 66% (57-75%) and 77% (65-89%). A flat, elevated low-grade carcinoma was missed by CTC. One cancer relapse was missed by CC, and a cecal cancer was missed by an incomplete CC and follow-up double-contrast barium enema. Conclusion: CC was superior to CTC and should remain first choice for the diagnosis of colorectal polyps. However, for diagnosis of lesions 10 mm, CTC and CC should be considered as complementary methods

  17. 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.)

  18. Predictors of incomplete optical colonoscopy using computed tomographic colonography.

    Science.gov (United States)

    Sachdeva, Reetika; Tsai, Salina D; El Zein, Mohamad H; Tieu, Alan A; Abdelgelil, Ahmed; Besharati, Sepideh; Khashab, Mouen A; Kalloo, Anthony N; Kumbhari, Vivek

    2016-01-01

    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. 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. On analysis, female gender (80% vs 58.6% P = 0.007), prior abdominal/pelvic surgeries (51.4% vs 14.3% P diverticulosis (P = 0.867) with incomplete OC. A scoring system to predict the outcome of OC is proposed based on CTC findings. 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.

  19. Magnetic resonance colonography in severe attacks of ulcerative colitis

    International Nuclear Information System (INIS)

    Savoye-Collet, C.; Roset, J.B.; Koning, E.; Dacher, J.N.; Charpentier, C.; Hommel, S.; Lerebours, E.; Savoye, G.

    2012-01-01

    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.)

  20. Magnetic resonance colonography with limited bowel preparation: a comparison of three strategies

    NARCIS (Netherlands)

    Florie, Jasper; van Gelder, Rogier E.; Haberkorn, Brigitte; Birnie, Erwin; Lavini, Cristina; Reitsma, Johannes B.; Stoker, Jaap

    2007-01-01

    PURPOSE: To prospectively compare three strategies of magnetic resonance colonography (MRC) with fecal tagging. MATERIALS AND METHODS: Three strategies were compared: (S1) gadolinium as oral tagging agent and a gadolinium-water mixture for rectal filling (bright lumen), (S2) oral barium and water

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

    International Nuclear Information System (INIS)

    Zijta, F.M.; Florie, J.; Jensch, S.; Bipat, S.; Nievelstein, R.A.J.; Poulus, M.; Thomassen-de Graaf, M.A.; Montauban van Swijndregt, A.D.; Stoker, J.

    2010-01-01

    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 (χ 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.

  2. Clinical aspects of MR colonography as a diagnostic tool.

    Science.gov (United States)

    Achiam, Michael

    2010-10-01

    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 seems to have a great potential in the screening for colorectal cancer, since detection of polyps and polypectomy might reduce on the incidence of colorectal cancer. This is speculated in the adenoma-carcinoma sequence theory, which states that most cancers evolve from polyps over a long period 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 complications (perforation, bleeding, death) and the lack of patient acceptance in colonoscopy, the need for a safe, patient friendly alternative examination with high sensitivity, is clear. In conclusion, in the three studies that made up this PhD thesis, we have shown: that there are some flaws to the present gold standard of colonic evaluation; that there is an increased morbidity and mortality in the group of patients with missed SC; that patients have a preference for MRC and for fecal tagging compared to CC and bowel purgation and that there is a potential gain in doing preoperative colonic evaluation with MRC on all patients with rectal- or sigmoid colon cancer.

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

    International Nuclear Information System (INIS)

    Paardt, M.P. van der; Zijta, F.M.; Boellaard, T.N.; Jensch, S.; Baak, L.C.; Depla, A.C.T.M.; Dekker, E.; Nederveen, A.J.; Bipat, S.; Stoker, J.

    2014-01-01

    Objectives: To evaluate the diagnostic performance of MR colonography using automated carbon dioxide (CO 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 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 2 insufflation for colonic distension in MR colonography

  4. Two-dimensional parallel acquisition technique in 3D MR colonography

    International Nuclear Information System (INIS)

    Steidle, G.; Schick, F.; Schaefer, J.; Schlemmer, H.P.; Claussen, C.D.

    2004-01-01

    Purpose: In-vitro and in-vivo examinations to investigate the influence of one (1D)- and two-dimensional (2D) parallel acquisition techniques (PAT) on contrast-to-noise ratio (CNR) and image quality for bright-lumen 3D MR colonography. Materials and Methods: In-vitro measurements were performed on a 1.5 T whole-body MR scanner (MAGNETOM AVANTO trademark , Siemens AG, Erlangen) with a standard spoiled 3D gradient-echo (3D GRE) sequence and a volume interpolated 3D GRE (VIBE) sequence using a home-built colon phantom. The relative CNR was determined and image quality evaluated for different acceleration factors (PAT factors). A bright-lumen 3D MR colonography with PAT factors 2, 3, 4 and 6 was performed on a 39-year-old volunteer. The 3D data sets were compared with regard to image quality. Results: The mean relative CNR values for the in-vitro measurements were 1, 0.81, 0.73, 0.52 and 0.4 (3D GRE) and 1, 0.8, 0.65, 0.45 and 0.3 (VIBE) for the PAT factors 1, 2, 3, 4 and 6, respectively. Residual aliasing artifacts not affecting image quality in a distinct manner were visible for 2D PAT, especially for the VIBE sequence. Increasing the PAT factor up to 6 and decreasing the acquisition time down to 10 seconds for the bright-lumen 3D MR colonography could achieve adequate image quality with significantly reduced image artifacts caused by peristalsis and pulsations. Discussion: Even for high PAT factors up to 6, 2D PAT only leads to a moderate CNR loss. For a 3D MR colonography, distinct shorter acquisition times can be achieved with identical resolution. (orig.)

  5. Computed tomography colonography in 2014: An update on technique and indications

    OpenAIRE

    Laghi, Andrea

    2014-01-01

    Twenty years after its introduction, computed tomographic colonography (CTC) has reached its maturity, and it can reasonably be considered the best radiological diagnostic test for imaging colorectal cancer (CRC) and polyps. This examination technique is less invasive than colonoscopy (CS), easy to perform, and standardized. Reduced bowel preparation and colonic distention using carbon dioxide favor patient compliance. Widespread implementation of a new image reconstruction algorithm has mini...

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

    International Nuclear Information System (INIS)

    Paardt, M.P. van der; Boellaard, T.N.; Zijta, F.M.; Baak, L.C.; Depla, A.C.T.M.; Dekker, E.; Nederveen, A.J.; Bipat, S.; Stoker, J.

    2015-01-01

    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

  7. 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.

  8. MR colonography with fecal tagging: comparison between 2D turbo FLASH and 3D FLASH sequences

    International Nuclear Information System (INIS)

    Papanikolaou, Nickolas; Grammatikakis, John; Maris, Thomas; Prassopoulos, Panos; Gourtsoyiannis, Nicholas; Lauenstein, Thomas

    2003-01-01

    The objective of this study was to compare inversion recovery turbo 2D fast low-angle shot (FLASH) and 3D FLASH sequences for fecal-tagged MR colonography studies. Fifteen consecutive patients with indications for colonoscopy underwent MR colonography with fecal tagging. An inversion recovery turbo-FLASH sequence was applied and compared in terms of artifacts presence, efficiency for masking residual stool, and colonic wall conspicuity with a fat-saturated 3D FLASH sequence. Both sequences were acquired following administration of paramagnetic contrast agent. Contrast-to-noise ratio and relative contrast between colonic wall and lumen were calculated and compared for both sequences. Turbo 2D FLASH provided fewer artifacts, higher efficiency for masking the residual stool, and colonic wall conspicuity equivalent to 3D FLASH. An inversion time of 10 ms provided homogeneously low signal intensity of the colonic lumen. Contrast to noise between colonic wall and lumen was significantly higher in the 3D FLASH images, whereas differences in relative contrast were not statistically significant. An optimized inversion-recovery 2D turbo-FLASH sequence provides better fecal tagging results and should be added to the 3D FLASH sequence when designing dark-lumen MR colonography examination protocols. (orig.)

  9. 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

    the possibilities for assigning tasks to less educated personnel groups such as radiographers.21 Until now, most research has focused on the technical capabilities of CTC; however, it is increasingly being realized that reader experience and training are equally important.22 In terms of how teaching cases......Background: Colorectal cancer (CRC) represents an important health problem in Western countries. In 2012, there were approximately 143,000 newly diagnosed cases of CRC in the US and nearly 52,000 deaths associated with this disease.1 In Europe, almost 413,000 individuals are newly diagnosed...... by Pickhardt et al., reported excellent accuracy for CTC, equal to or better than OC.4 This group's results have been attributed to state of the art scanning and software, using 3D as the primary read and fecal tagging. Similarly, the published American College of Radiology Imaging Network (ACRIN) multi...

  10. Case Report: Rectal perforation during CT colonography [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Marianna Zukiwskyj

    2016-03-01

    Full Text Available Introduction Computer tomography colonoscopy (CTC is an increasingly prevalent procedure for the investigation of colorectal symptoms, or as a component of colorectal cancer screening.  It is considered a low risk procedure, however colonic perforation is a recognized significant complication.   Case Report We report the case of an 81-year-old female patient who underwent CTC after failed optical colonoscopy as part of routine colorectal cancer screening.  Perforation of the rectum with surrounding pararectal air was confirmed on CTC.  The patient had minimal symptoms and was treated successful non-operatively with bowel rest and antibiotics.   Conclusion Perforation sustained during CTC is an uncommon complication.  The incidence of perforation during CTC is still lower than that during optical colonoscopy.  In the absence of significant abdominal signs and symptoms, this rare complication may be successfully managed non-operatively.

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

    International Nuclear Information System (INIS)

    Kim, Ji Yeon; Park, Seong Ho; Lee, Seung Soo; Kim, Ah Young; Ha, Hyun Kwon

    2011-01-01

    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.)

  12. Low radiation dose multislice CT colonography in children: Experience after 100 studies

    International Nuclear Information System (INIS)

    Capunay, Carlos M.; Carrascosa, Patricia M.; Bou-Khair, Adriana; Castagnino, Norma; Ninomiya, Ines; Carrascosa, Jorge M.

    2005-01-01

    The purpose of this study was to determine the sensitivity (S) and specificity (sp) of virtual colonoscopy in the detection of elevated lesions in children, and to compare these results with conventional colonoscopy. Between April 2000 and January 2003, 100 patients (mean: 6 years old) were evaluated with virtual colonoscopy and conventional colonoscopy. All patients presented rectal bleeding and both methods were performed the same day. All patients had received a standard bowel cleansing the day before. Virtual colonoscopies were carried out with 2.5 mm thick slices, 1.3 mm reconstruction intervals, 15 mA s, and 90 kV. The acquisition time ranged from 5-10 s depending on the age of the patient. For each method, two scans were performed in both a supine and a prone position. After the acquisitions, images were reprocessed using two-dimensional, volume rendering, and virtual endoscopy reconstructions. Findings of the two methods were compared blinded. They were classified in two groups: (1) normal studies, and (2) elevated lesions studies. The second group was subdivided according to the diameter of the lesions: (2a) 9 mm. All studies were performed without complications. Forty-eight patients were normal. In the other 52 patients, virtual colonoscopy detected 86 lesions, whereas conventional colonoscopy depicted only 80 lesions. There were 70 true-positive findings, 48 true-negative findings, 12 false-positive findings, and 8 false-negative findings. The global S was 89%, sp: 80%, positive predictive value: 85%, and negative predictive value: 85%. In group (2a), sensitivity, specificity, positive predictive value, and negative predictive value were 81, 90, 81, and 90% respectively; in group (2b), 90, 90, 85, and 94%, respectively; and in group (2c), 100, 96, 90, and 100%, respectively. We concluded that virtual colonoscopy is an alternative method for the evaluation of children with elevated lesions. It is fast, has no complications, and uses a low radiation dose

  13. Automated polyp measurement based on colon structure decomposition for CT colonography

    Science.gov (United States)

    Wang, Huafeng; Li, Lihong C.; Han, Hao; Peng, Hao; Song, Bowen; Wei, Xinzhou; Liang, Zhengrong

    2014-03-01

    Accurate assessment of colorectal polyp size is of great significance for early diagnosis and management of colorectal cancers. Due to the complexity of colon structure, polyps with diverse geometric characteristics grow from different landform surfaces. In this paper, we present a new colon decomposition approach for polyp measurement. We first apply an efficient maximum a posteriori expectation-maximization (MAP-EM) partial volume segmentation algorithm to achieve an effective electronic cleansing on colon. The global colon structure is then decomposed into different kinds of morphological shapes, e.g. haustral folds or haustral wall. Meanwhile, the polyp location is identified by an automatic computer aided detection algorithm. By integrating the colon structure decomposition with the computer aided detection system, a patch volume of colon polyps is extracted. Thus, polyp size assessment can be achieved by finding abnormal protrusion on a relative uniform morphological surface from the decomposed colon landform. We evaluated our method via physical phantom and clinical datasets. Experiment results demonstrate the feasibility of our method in consistently quantifying the size of polyp volume and, therefore, facilitating characterizing for clinical management.

  14. Study of the usefulness of large intestine screening inspections using multi-slice CT (MSCT)

    International Nuclear Information System (INIS)

    Yamasaki, Michihiro; Nonogaki, Hidehiko; Hara, Koji; Naruse, Yutaka; Hara, Hiroto; Suematsu, Seiji; Yanase, Tadahiko; Otou, Taiji

    2005-01-01

    CT-colonography (CT-C), a new diagnostic imaging technique for cancer of the large intestine-which is increasing rapidly owing to westernized eating habits-has advanced from the developmental stage to the stage of practical application, thanks to progress in MSCT and workstation development. Therefore, based on the results of CT-C application using 16 lines of MSCT to a screening test, we reviewed the usefulness of CT-C in our clinic. We supplemented defective depiction, and found that change of position was effective for virtual image exclusion. We consider that CT-C can support diagnosis if the target of screening tests is a polypoid lesion of more than 6 mm. In addition, it is expected that the number of examinations performed during office visits will increase because of the decreased invasiveness of the procedure, its lack of pain, and its ability to provide early lesion detection. (author)

  15. Feasibility study of using air as a contrast medium in MR colonography

    International Nuclear Information System (INIS)

    So, N.M.C.; Lam, W.W.M.; Mann, D.; Leung, K.L.; Metreweli, C.

    2003-01-01

    AIM: To evaluate the feasibility of using air as intraluminal contrast medium in magnetic resonance (MR) colonography. MATERIALS AND METHODS: Twenty-two patients underwent MR colonography (MRC) using air before colonoscopy. All patients were imaged in prone and supine positions. Each colon was divided into five segments. Two radiologists reviewed the images for the degree of colonic distension, image quality and colonic lesions. The colonic lesions identified using MR were compared with those identified on colonoscopy. RESULTS: Eight men and 14 women with mean age of 55.5 years were studied. All patients completed the MR examination. One hundred and five out of 110 (95.5%) colonic segments were well distended in both prone and supine positions. Image quality was good in all cases. Colonoscopy detected 16 lesions: three ≥1 cm, one 7 mm lesion and 12 lesions ≤5 mm. All lesions 1 cm or larger were detected by MRC. CONCLUSION: MRC using air and the single-shot half-Fourier rapid acquisition with refocused echos (RARE) technique is feasible. But in this small pilot study, it had low sensitivity for the detection of polyps less than 1 cm in diameter

  16. Magnetic resonance colonography versus colonoscopy as a diagnostic investigation for colorectal cancer: a meta-analysis

    International Nuclear Information System (INIS)

    Purkayastha, S.; Tekkis, P.P.; Athanasiou, T.; Aziz, O.; Negus, R.; Gedroyc, W.; Darzi, A.W.

    2005-01-01

    AIMS: Magnetic resonance colonography (MRC) is emerging as a potential complementary investigation for the diagnosis of colorectal cancer (CRC) and also for benign pathology such as diverticular disease. A meta-analysis reporting the use of MRC is yet to be performed. The aim of this study was to evaluate the diagnostic accuracy of MRC compared with the gold-standard investigation, conventional colonoscopy (CC). METHODS: A literature search was carried out to identify studies containing comparative data between MRC findings and CC findings. Quantitative meta-analysis for diagnostic tests was performed, which included the calculation of independent sensitivities, specificities, diagnostic odds ratios, the construction of summary receiver operating characteristic (SROC) curves, pooled analysis and sensitivity analysis. The study heterogeneity was evaluated by the Q-test using a random-effect model to accommodate the cluster of outcomes between individual studies. RESULTS: In all, 8 comparative studies were identified, involving 563 patients. The calculated pooled sensitivity for all lesions was 75% (95% CI: 47% to 91%), the specificity was 96% (95% CI: 86% to 98%) and the area under the ROC curve was 90% (weighted). On sensitivity analysis, MRC had a better diagnostic accuracy for CRC than for polyps, with a sensitivity of 91% (95% CI: 97% to 91%), a specificity of 98% (95% CI: 66% to 99%) and an area under the ROC curve of 92%. There was no significant heterogeneity between the studies with regard to the diagnostic accuracy of MRC for CRC. CONCLUSION: This meta-analysis suggests that MRC is an imaging technique with high discrimination for cases presenting with colorectal cancer. The exact diagnostic role of MRC needs to be clarified (e.g. suitable for an elderly person with suspected CRC). Further evaluation is necessary to refine its applicability and diagnostic accuracy in comparison with other imaging methods such as computed tomography colonography

  17. 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.

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

    DEFF Research Database (Denmark)

    Achiam, M P; Andersen, L P H; Klein, M

    2010-01-01

    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-enhance......-enhanced MR imaging combined with MR colonography could be used to differentiate a benign from a malignant obstructing colon tumor....

  19. Head CT scan

    Science.gov (United States)

    ... CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - ... Head CT is done in the hospital or radiology center. You lie on a narrow table that ...

  20. CT Enterography

    Science.gov (United States)

    ... 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 ...

  1. 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)

  2. 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.)

  3. A novel colonic polyp volume segmentation method for computer tomographic colonography

    Science.gov (United States)

    Wang, Huafeng; Li, Lihong C.; Han, Hao; Song, Bowen; Peng, Hao; Wang, Yunhong; Wang, Lihua; Liang, Zhengrong

    2014-03-01

    Colorectal cancer is the third most common type of cancer. However, this disease can be prevented by detection and removal of precursor adenomatous polyps after the diagnosis given by experts on computer tomographic colonography (CTC). During CTC diagnosis, the radiologist looks for colon polyps and measures not only the size but also the malignancy. It is a common sense that to segment polyp volumes from their complicated growing environment is of much significance for accomplishing the CTC based early diagnosis task. Previously, the polyp volumes are mainly given from the manually or semi-automatically drawing by the radiologists. As a result, some deviations cannot be avoided since the polyps are usually small (6~9mm) and the radiologists' experience and knowledge are varying from one to another. In order to achieve automatic polyp segmentation carried out by the machine, we proposed a new method based on the colon decomposition strategy. We evaluated our algorithm on both phantom and patient data. Experimental results demonstrate our approach is capable of segment the small polyps from their complicated growing background.

  4. Magnetic Resonance Colonography May Predict the Need for Bowel Resection in Colorectal Endometriosis

    Directory of Open Access Journals (Sweden)

    Arnaldo Scardapane

    2017-01-01

    Full Text Available Purpose. To define if MRI findings in patients with deep pelvic endometriosis (DPE may be predictive for the need of bowel resection. Material and Methods. A retrospective survey of 196 pelvic MRIs of women who received laparoscopic procedures for DPE was carried out. A pelvic MRI was performed in all patients: it consisted in T2w-TSE sequences in axial, sagittal, and coronal planes and T1w and THRIVE sequences in the axial plane; the exam was completed by MR-Colonography. Intestinal lesions were measured in short and long axis and the degree of stenosis was established. A multivariate logistic regression was used to identify the predictors of intestinal resection. Results. 57/196 patients received an intestinal resection. Multivariate logistic regression demonstrated a predictive value of short axis (Odds-Ratio = 2.29, p=0.011 and stenosis (Odds-Ratio = 1.20, p=0.003. ROC analysis showed that a cut-off value of 11 mm for the short axis and 30% for the stenosis may correctly classify, respectively, 96,94% (sensitivity 92,9% and specificity 98,56% and 97,96% (sensitivity 94,74% and specificity 99,3% of the cases. Conclusion. The presence of an endometriotic rectal nodule > 11 mm in short axis causing a stenosis > 30% in pelvic MRI reliably predicts the need of a rectal resection.

  5. Diagnosis of colorectal endometriosis: contribution of contrast enhanced MR-colonography

    Energy Technology Data Exchange (ETDEWEB)

    Scardapane, Arnaldo; Lorusso, Filomenamila; Stabile Ianora, Amato Antonio; Lasciarrea, Maurilia; Angelelli, Giuseppe [University Hospital Policlinico, Department of Internal Medicine and Public Health (Di.M.I.M.P.) - Section of Diagnostic Imaging, Bari (Italy); Bettocchi, Stefano; Vimercati, Antonella; Ceci, Oronzo [University Hospital Policlinico, Department of General and Specialistic Surgical Sciences, Section of Obstetrics and Gynaecology, Bari (Italy)

    2011-07-15

    To investigate the contribution of contrast-enhanced MR-colonography (CE-MR-C) for the diagnosis of intestinal endometriosis. One hundred and four women with suspected endometriosis were prospectively enrolled. All patients were subjected to MRI consisting of two phases: pelvic high-resolution MRI (HR-MRI) followed by CE-MR-C after colonic distension using a 1.5-liter water enema and injection of 0.15 ml/kg of 0.5 M gadolinium-DTPA with T1w high-resolution isotropic volume (THRIVE) and balanced turbo field echo (BTFE) images. HR-MRI and CE-MR-C were considered as two datasets, which were independently reviewed by two radiologists with 12 and 2 years' experience respectively. The presence of deep pelvic endometriotic lesions with particular attention to colorectal involvement was recorded. MRI findings correlated with laparoscopy in all cases. Thanks to CE-MR-C images, sensitivity, specificity, PPV, NPV and accuracy for diagnosis of colorectal endometriosis increased from 76%, 96%, 84%, 93% and 91%, to 95%, 97%, 91%, 99% and 97% for the most experienced radiologist and from 62%, 93%, 72%, 89% and 85%, to 86%, 94%, 82%, 96% and 92% for the less experienced radiologist; moreover, the interobserver agreement increased from 0.63 to 0.80 (Cohen's K test). CE-MR-C allows easier recognition of colorectal endometriosis and higher interobserver agreement. (orig.)

  6. Diagnosis of colorectal endometriosis: contribution of contrast enhanced MR-colonography

    International Nuclear Information System (INIS)

    Scardapane, Arnaldo; Lorusso, Filomenamila; Stabile Ianora, Amato Antonio; Lasciarrea, Maurilia; Angelelli, Giuseppe; Bettocchi, Stefano; Vimercati, Antonella; Ceci, Oronzo

    2011-01-01

    To investigate the contribution of contrast-enhanced MR-colonography (CE-MR-C) for the diagnosis of intestinal endometriosis. One hundred and four women with suspected endometriosis were prospectively enrolled. All patients were subjected to MRI consisting of two phases: pelvic high-resolution MRI (HR-MRI) followed by CE-MR-C after colonic distension using a 1.5-liter water enema and injection of 0.15 ml/kg of 0.5 M gadolinium-DTPA with T1w high-resolution isotropic volume (THRIVE) and balanced turbo field echo (BTFE) images. HR-MRI and CE-MR-C were considered as two datasets, which were independently reviewed by two radiologists with 12 and 2 years' experience respectively. The presence of deep pelvic endometriotic lesions with particular attention to colorectal involvement was recorded. MRI findings correlated with laparoscopy in all cases. Thanks to CE-MR-C images, sensitivity, specificity, PPV, NPV and accuracy for diagnosis of colorectal endometriosis increased from 76%, 96%, 84%, 93% and 91%, to 95%, 97%, 91%, 99% and 97% for the most experienced radiologist and from 62%, 93%, 72%, 89% and 85%, to 86%, 94%, 82%, 96% and 92% for the less experienced radiologist; moreover, the interobserver agreement increased from 0.63 to 0.80 (Cohen's K test). CE-MR-C allows easier recognition of colorectal endometriosis and higher interobserver agreement. (orig.)

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

    International Nuclear Information System (INIS)

    Behrens, C.; Stevenson, G.; Eddy, R.; Mathieson, J.

    2008-01-01

    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)

  8. Utility of dark-lumen MR colonography for the assessment of extra-colonic organs

    International Nuclear Information System (INIS)

    Ajaj, Waleed; Goyen, Mathias; Ruehm, Stefan G.; Ladd, Susanne C.; Gerken, Guido

    2007-01-01

    The aim of the study was to evaluate the utility of dark-lumen MR colonography (MRC) for the assessment of extra-colonic organs. Three hundred seventy-five subjects with suspected colonic disease underwent a complete MRC examination. MRC data were evaluated by two radiologists in a blinded fashion. In addition to the large bowel, the extra-intestinal organs from the lung bases to the pelvis were assessed for the presence of pathologies. All findings were divided into known or unknown findings and therapeutically relevant or irrelevant findings. If deemed necessary, other diagnostic imaging tests to further assess those findings were performed. In total, 510 extra-colonic findings were found in 260 (69%) of the 375 subjects. Known extra-colonic findings were found in 140 subjects (54%) and unknown findings in 120 subjects (46%). Thirty-one (12%) of the 260 subjects had therapeutically relevant findings (45 findings); 229 patients (88%) had irrelevant findings (465 findings). Dark-lumen MRC is a useful tool not only for the assessment of the entire colon, but also for the evaluation of extra-colonic organs. Thus, intra- and extra-colonic pathologies can be diagnosed within the same examination. (orig.)

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

    International Nuclear Information System (INIS)

    Ajaj, Waleed; Lauenstein, Thomas; Goehde, Susanne; Kuehle, Christiane; Herborn, Christoph U.; Ruehm, Stefan G.; Langhorst, Jost; Zoepf, Thomas; Gerken, Guido; Goyen, Mathias

    2005-01-01

    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.)

  10. MR colonography vs. optical colonoscopy: comparison of patients' acceptance in a screening population

    International Nuclear Information System (INIS)

    Kinner, Sonja; Kuehle, Christiane A.; Ladd, Susanne C.; Nuefer, Michael; Barkhausen, Joerg; Langhorst, Jost; Zoepf, Thomas; Gerken, Guido; Lauenstein, Thomas C.

    2007-01-01

    The aim of this study was to compare optical colonoscopy to fecal-tagging-based MR colonography in a screening population in terms of comfort and acceptance ratings as well as for future preferences as colorectal cancer screening examinations. Two hundred eighty-four asymptomatic patients (mean age 59 years) underwent MRC and OC within 4 weeks. While MRC was based on a fecal tagging technique, OC was performed after bowel cleansing. For OC, sedatives and analgesics were used. Patients evaluated both modalities and certain aspects of the examination according to a 10-point-scale with higher scores denoting a worse experience. Furthermore, preferences for future examinations were evaluated. No significant difference was noted for the overall acceptance of OC (mean value 3.0) and MRC (mean value 3.4). For MRC, the placement of the rectal tube was rated as the most unpleasant part, whereas bowel purgation was regarded most inconvenient for OC. Patients aged 55 years and older perceived most aspects less unpleasant than younger patients. Of the patients, 46% preferred MRC for future screening examinations (OC: 44%). OC and MRC have comparable general acceptance levels in a screening population. Especially for patients declining endoscopy as a screening method MRC may evolve as an attractive alternative. (orig.)

  11. 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.

  12. 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

  13. Clinical indications for computed tomographic colonography: European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline

    NARCIS (Netherlands)

    Spada, Cristiano; Stoker, Jaap; Alarcon, Onofre; Barbaro, Federico; Bellini, Davide; Bretthauer, Michael; de Haan, Margriet C.; Dumonceau, Jean-Marc; Ferlitsch, Monika; Halligan, Steve; Helbren, Emma; Hellstrom, Mikael; Kuipers, Ernst J.; Lefere, Philippe; Mang, Thomas; Neri, Emanuele; Petruzziello, Lucio; Plumb, Andrew; Regge, Daniele; Taylor, Stuart A.; Hassan, Cesare; Laghi, Andrea

    2014-01-01

    This is an official guideline of the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR). It addresses the clinical indications for the use of computed tomographic colonography (CTC). A targeted literature search was

  14. Comparison of axial, coronal, and primary 3D review in MDCT colonography for the detection of small polyps: a phantom study

    NARCIS (Netherlands)

    Mang, Thomas; Schaefer-Prokop, Cornelia; Schima, Wolfgang; Maier, Andrea; Schober, Ewald; Mueller-Mang, Christina; Weber, Michael; Prokop, Mathias

    2009-01-01

    The purpose of this phantom study is to compare the influence of the reading technique (axial images alone in comparison to 3D endoluminal, coronal, and combined 2D/3D review methods) on the sensitivity and inter-reader variability with MDCT colonography for the detection of small colonic polyps. An

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

    International Nuclear Information System (INIS)

    Ajaj, Waleed; Lauenstein, Thomas C.; Kuehle, Christiane; Herborn, Christoph U.; Goehde, Susanne C.; Schneemann, Hubert; Ruehm, Stefan G.; Goyen, Mathias

    2005-01-01

    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.)

  16. Computed tomography colonography in 2014: an update on technique and indications.

    Science.gov (United States)

    Laghi, Andrea

    2014-12-07

    Twenty years after its introduction, computed tomographic colonography (CTC) has reached its maturity, and it can reasonably be considered the best radiological diagnostic test for imaging colorectal cancer (CRC) and polyps. This examination technique is less invasive than colonoscopy (CS), easy to perform, and standardized. Reduced bowel preparation and colonic distention using carbon dioxide favor patient compliance. Widespread implementation of a new image reconstruction algorithm has minimized radiation exposure, and the use of dedicated software with enhanced views has enabled easier image interpretation. Integration in the routine workflow of a computer-aided detection algorithm reduces perceptual errors, particularly for small polyps. Consolidated evidence from the literature shows that the diagnostic performances for the detection of CRC and large polyps in symptomatic and asymptomatic individuals are similar to CS and are largely superior to barium enema, the latter of which should be strongly discouraged. Favorable data regarding CTC performance open the possibility for many different indications, some of which are already supported by evidence-based data: incomplete, failed, or unfeasible CS; symptomatic, elderly, and frail patients; and investigation of diverticular disease. Other indications are still being debated and, thus, are recommended only if CS is unfeasible: the use of CTC in CRC screening and in surveillance after surgery for CRC or polypectomy. In order for CTC to be used appropriately, contraindications such as acute abdominal conditions (diverticulitis or the acute phase of inflammatory bowel diseases) and surveillance in patients with a long-standing history of ulcerative colitis or Crohn's disease and in those with hereditary colonic syndromes should not be overlooked. This will maximize the benefits of the technique and minimize potential sources of frustration or disappointment for both referring clinicians and patients.

  17. Thoracic CT

    Science.gov (United States)

    ... through a vein (IV) in your hand or forearm. It may be given through the rectum using ... CT scan Vertebra, thoracic (mid back) Normal lung anatomy Thoracic organs References Gotway MB, Panse PM, Gruden ...

  18. Feasibility of using automated insufflated carbon dioxide (CO2) for luminal distension in 3.0 T MR colonography

    International Nuclear Information System (INIS)

    Zijta, F.M.; Nederveen, A.J.; Jensch, S.; Florie, J.; Bipat, S.; Paardt, M.P. van der; Montauban van Swijndregt, A.D.; Stoker, J.

    2012-01-01

    Purpose: Primary aim of our study was to prospectively evaluate the feasibility of automated carbon dioxide (CO 2 ) delivery as luminal distending agent in 3.0 T MR colonography. Materials and methods: Rectally insufflated CO 2 was evaluated in four groups with different bowel preparation (A–D). Bowel preparation regimes were: gadolinium-based tagging (A), bowel purgation (B), barium-based tagging (C) and iodine-based tagging (D). Supine (3D)T1w-FFE and (2D)T2w-SSFSE series were acquired. Each colon was divided into six segments (cecum S1–rectum S6). Two observers independently assessed the presence of artefacts, diagnostic confidence and segmental colonic distension. Also characteristics of the residual stool (presence, composition and signal-intensity) were assessed per segment. Discomfort was assessed with questionnaires. Results: Fourteen healthy subjects were included. Colonic distension by means of rectally insufflated CO 2 was not associated with susceptibility artefacts. Overall image quality was affected by the presence of bowel motion-related artefacts: none of the segments in 3DT1w-series and 10/84 (12%) colon segments in 2DT2w-series were rated artefact-free by both observers. Diagnostic confidence ratings were superior for the 2DT2w-SSFSE series. Overall bowel distension was rated adequate to optimal in 312/336 (93%) colon segments. Conclusion: MR colonography at 3.0 T using carbon dioxide (CO 2 ) for colonic distension is technically feasible. The presence of intraluminal CO 2 did not result in susceptibility artefacts, although overall image quality was influenced by artefacts.

  19. CT Scan

    Science.gov (United States)

    ... ll likely be told to drink lots of fluids to help your kidneys remove the contrast material from your body. Results CT images are stored as electronic data files and are usually reviewed on a computer screen. A radiologist interprets these images and sends ...

  20. 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 ...

  1. CT cystography

    International Nuclear Information System (INIS)

    Tsili, A.

    2012-01-01

    Full text: Cancer of the urinary bladder is one of the commonest urothelial neoplasms. Conventional cystoscopy remains the mainstay in the diagnosis of urinary bladder carcinomas. But it is an invasive and uncomfortable procedure, associated with complications. Computed tomographic (CT) virtual cystoscopy has been proposed as an alternative imaging modality with potential advantages in the detection of urinary bladder neoplasms and good patient acceptance. It is a minimally invasive technique, allowing imaging of the urinary bladder in multiple planes and a 360 0 view. CT cystoscopy provides information about the location, size and morphologic features of urinary bladder lesions, indicating appropriate areas for biopsy. It can be performed in cases in which conventional cystoscopy is not feasible, such as in the presence of urethral strictures, marked prostatic hypertrophy or active bleeding, and in cases in which cystoscopic findings are inconclusive. The technique can be used to evaluate areas of the urinary bladder difficult to evaluate with cystoscopy, such as the anterior bladder neck and narrowmouthed diverticula. Finally, virtual cystoscopy provides both intraluminal and extraluminal pathologic changes, so intravesical disease and exrtavesical extension can be evaluated in the same study. One of the limitations of this technique is the difficulty to demonstrate small-sized lesions. The introduction of multi-detector row CT (MDCT) scanners was a major technological advancement because among other things it substantially improves z-axis resolution by reducing section collimation and allowing the detection of very small lesions. The near isotropic or isotropic pixels achieved with a multidetector CT scanner, enable the creation of multiplanar reformatted images with a resolution very close to that of the axial images and three-dimensional (3D) renderings of outstanding quality. Transverse, multiplanar reformations and virtual endoscopic images are complementary

  2. 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.)

  3. 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 ...

  4. 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 ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, ... than regular radiographs (x-rays). top of page What are some common uses of the procedure? CT ...

  6. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... are the limitations of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed ... nasal cavity by small openings. top of page What are some common uses of the procedure? CT ...

  7. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  9. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  10. Computed tomographic colonography vs rectal water- contrast transvaginal sonography in diagnosis of rectosigmoid endometriosis: a pilot study.

    Science.gov (United States)

    Ferrero, S; Biscaldi, E; Vellone, V G; Venturini, P L; Leone Roberti Maggiore, U

    2017-04-01

    To compare the performance of computed tomographic colonography (CTC) and rectal water-contrast transvaginal sonography (RWC-TVS) in the diagnosis of rectosigmoid endometriosis, and compare precision in estimating the length of the rectosigmoid nodules and the distance between the nodules and the anal verge. This prospective study included 70 patients of reproductive age with clinical suspicion of rectosigmoid endometriosis. Patients underwent RWC-TVS and CTC before laparoscopic excision of endometriotic nodules. The findings of RWC-TVS and CTC were compared with surgical and histological results. Of the 70 patients included in the study, 40 (57.1%) had rectosigmoid endometriosis. CTC and RWC-TVS had similar accuracy in the diagnosis of rectosigmoid endometriosis (P = 0.508) and similar precision in estimating the length of the endometriotic nodules (P = 0.077). CTC was more precise than RWC-TVS in estimating the distance between the rectosigmoid nodule and the anal verge (P endometriosis and similar precision in estimating the size of the nodules; however, CTC is more precise than RWC-TVS in estimating the distance between the nodules and the anal verge, yet patients tolerate RWC-TVS better than CTC. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

  11. Computer-aided detection in computed tomography colonography. Current status and problems with detection of early colorectal cancer

    International Nuclear Information System (INIS)

    Morimoto, Tsuyoshi; Nakijima, Yasuo; Iinuma, Gen; Arai, Yasuaki; Shiraishi, Junji; Moriyama, Noriyuki; Beddoe, G.

    2008-01-01

    The aim of this study was to evaluate the usefulness of computer-aided detection (CAD) in diagnosing early colorectal cancer using computed tomography colonography (CTC). A total of 30 CTC data sets for 30 early colorectal cancers in 30 patients were retrospectively reviewed by three radiologists. After primary evaluation, a second reading was performed using CAD findings. The readers evaluated each colorectal segment for the presence or absence of colorectal cancer using five confidence rating levels. To compare the assessment results, the sensitivity and specificity with and without CAD were calculated on the basis of the confidence rating, and differences in these variables were analyzed by receiver operating characteristic (ROC) analysis. The average sensitivities for the detection without and with CAD for the three readers were 81.6% and 75.6%, respectively. Among the three readers, only one reader improved sensitivity with CAD compared to that without. CAD decreased specificity in all three readers. CAD detected 100% of protruding lesions but only 69.2% of flat lesions. On ROC analysis, the diagnostic performance of all three readers was decreased by use of CAD. Currently available CAD with CTC does not improve diagnostic performance for detecting early colorectal cancer. An improved CAD algorithm is required for detecting fiat lesions and reducing the false-positive rate. (author)

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

    International Nuclear Information System (INIS)

    Yusuf, Erlangga; Florie, Jasper; Nio, Chung Yung; Jensch, Sebastian; Nievelstein, Rutger A.J.; Baak, Lubbertus; Stoker, Jaap

    2011-01-01

    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.

  13. 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).

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

    International Nuclear Information System (INIS)

    Achiam, M.P.; Andersen, L.P.H.; Klein, M.; Logager, V.; Chabanova, E.; Thomsen, H.S.; Rosenberg, J.

    2010-01-01

    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).

  15. Cost-effectiveness modeling of colorectal cancer: Computed tomography colonography vs colonoscopy or fecal occult blood tests

    International Nuclear Information System (INIS)

    Lucidarme, Olivier; Cadi, Mehdi; Berger, Genevieve; Taieb, Julien; Poynard, Thierry; Grenier, Philippe; Beresniak, Ariel

    2012-01-01

    Objectives: To assess the cost-effectiveness of three colorectal-cancer (CRC) screening strategies in France: fecal-occult-blood tests (FOBT), computed-tomography-colonography (CTC) and optical-colonoscopy (OC). Methods: Ten-year simulation modeling was used to assess a virtual asymptomatic, average-risk population 50–74 years old. Negative OC was repeated 10 years later, and OC positive for advanced or non-advanced adenoma 3 or 5 years later, respectively. FOBT was repeated biennially. Negative CTC was repeated 5 years later. Positive CTC and FOBT led to triennial OC. Total cost and CRC rate after 10 years for each screening strategy and 0–100% adherence rates with 10% increments were computed. Transition probabilities were programmed using distribution ranges to account for uncertainty parameters. Direct medical costs were estimated using the French national health insurance prices. Probabilistic sensitivity analyses used 5000 Monte Carlo simulations generating model outcomes and standard deviations. Results: For a given adherence rate, CTC screening was always the most effective but not the most cost-effective. FOBT was the least effective but most cost-effective strategy. OC was of intermediate efficacy and the least cost-effective strategy. Without screening, treatment of 123 CRC per 10,000 individuals would cost €3,444,000. For 60% adherence, the respective costs of preventing and treating, respectively 49 and 74 FOBT-detected, 73 and 50 CTC-detected and 63 and 60 OC-detected CRC would be €2,810,000, €6,450,000 and €9,340,000. Conclusion: Simulation modeling helped to identify what would be the most effective (CTC) and cost-effective screening (FOBT) strategy in the setting of mass CRC screening in France.

  16. 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.

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

    International Nuclear Information System (INIS)

    Keeling, Aoife N.; Morrin, Martina M.; McKenzie, Charles; Farrell, Richard J.; Sheth, Sunil G.; Ngo, Long; Bloch, B. Nicolas; Pedrosa, Ivan; Rofsky, Neil M.

    2012-01-01

    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 ≥10 mm, 4 polyps 6–9 mm, 15 polyps ≤5 mm). 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 10 mm, 100% (4/4) and 100% (20/20) for lesions 6–9 mm, and sensitivity of 20% (3/15) lesions less than 5 mm. The sensitivity and specificity of MRC for detecting significant lesions (>6 mm) 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 ≥6 mm in size. Further studies are warranted.

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... images and send an official report to your primary care physician or physician who referred you for ... of soft tissue (particularly the brain, including the disease processes) are less visible on CT scans . 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 ... head CT scanning. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  1. 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 ...

  4. Body CT (CAT Scan)

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    ... 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 ...

  5. Abdominal and Pelvic CT

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  8. Computed Tomography (CT) -- Sinuses

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  9. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography ( ... cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even ...

  10. 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 ...

  11. 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 ...

  12. 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 ...

  13. 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 ...

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    Full Text Available ... time, resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they ... the technologist verifies that the images are of high enough quality for accurate interpretation. The actual CT ...

  15. Abdominal and Pelvic CT

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    Full Text Available ... time, resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they ... the technologist verifies that the images are of high enough quality for accurate interpretation. The CT examination ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... time, resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they ... the technologist verifies that the images are of high enough quality for accurate interpretation. A CT scan ...

  17. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... allows the body parts to be distinguished from one another on an x-ray film or CT ... benefits vs. risks? Benefits A CT scan is one of the safest means of studying the sinuses. ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... the nasal cavity by small openings. top of page What are some common uses of the procedure? CT ... information about pregnancy and x-rays. top of page What does the equipment look like? The CT scanner ...

  19. Abdominal and Pelvic CT

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    Full Text Available ... of soft tissues and blood vessels. top of page What are some common uses of the procedure? This ... information about pregnancy and x-rays. top of page What does the CT equipment look like? The CT ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... a technique called CT angiography. For more information, see the CT Angiography page . top of page How ... is any possibility that they may be pregnant. See the Safety page for more information about pregnancy ...

  1. Abdominal and Pelvic CT

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    Full Text Available ... of CT Scanning of the Abdomen and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed ... soft tissues and blood vessels. top of page What are some common uses of the procedure? This ...

  2. Computed Tomography (CT) -- Sinuses

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

  3. Computed Tomography (CT) -- Head

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

  4. Computed Tomography (CT) -- Sinuses

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

  5. 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 ... actual CT scanning is performed. Depending on the type of CT scan, the machine may make several ...

  6. Computed Tomography (CT) -- Sinuses

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  7. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  8. Computed Tomography (CT) -- Head

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  9. Computed Tomography (CT) -- Head

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  10. Computed Tomography (CT) -- Sinuses

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  11. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the nasal cavity. CT ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail ...

  12. Computed Tomography (CT) -- Head

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    Full Text Available ... see the CT Angiography page . top of page How should I prepare? You should wear comfortable, loose- ... of a speaker and microphone. top of page How does the procedure work? In many ways CT ...

  13. Computed Tomography (CT) -- Head

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

  14. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can ... to ensure that you are properly positioned. With modern CT scanners, you will hear only slight buzzing, ...

  15. Abdominal and Pelvic CT

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    Full Text Available ... resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can ... to ensure that you are properly positioned. With modern CT scanners, you will hear only slight buzzing, ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can ... to ensure that you are properly positioned. With modern CT scanners, you will hear only slight buzzing, ...

  17. Abdominal and Pelvic CT

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    Full Text Available ... CT scanner or may be over the weight limit—usually 450 pounds—for the moving table. CT ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  20. Abdominal and Pelvic CT

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    Full Text Available ... CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  1. 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 ... the technologist verifies that the images are of high enough quality for accurate interpretation. The actual CT ...

  2. 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 ... the technologist verifies that the images are of high enough quality for accurate interpretation. A CT scan ...

  3. Computed Tomography (CT) -- Head

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

  4. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... air-filled spaces within the bones of the face surrounding the nasal cavity. CT scanning is painless, ... and blood vessels. A CT scan of the face produces images that also show a patient's paranasal ...

  5. 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 ...

  6. 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 ...

  7. 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.)

  8. 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

  9. CT Perfusion of the Head

    Science.gov (United States)

    ... Site Index A-Z CT Perfusion of the Head Computed tomography (CT) perfusion of the head uses ... the Head? What is CT Perfusion of the Head? Computed tomography (CT) perfusion imaging shows which areas ...

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

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    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 ...

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

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    Full Text Available ... on newborns, infants and older children. top of page What are some common uses of the procedure? CT ... your child for the CT examination. top of page What does the CT equipment look like? The CT ...

  12. Computed Tomography (CT) -- Head

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    Full Text Available ... Perfusion of the Head CT Angiography (CTA) Stroke Brain Tumors Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - Head Videos related to Computed Tomography ( ...

  13. Computed Tomography (CT) -- Head

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    Full Text Available ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography ( ...

  14. 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...

  15. Spinal CT scan, 2

    International Nuclear Information System (INIS)

    Nakagawa, Hiroshi

    1982-01-01

    Plain CT described fairly accurately the anatomy and lesions of the lumbar and sacral spines on their transverse sections. Since hernia of the intervertebral disc could be directly diagnosed by CT, indications of myelography could be restricted. Spinal-canal stenosis of the lumbar spine occurs because of various factors, and CT not only demonstrated the accurate size and morphology of bony canals, but also elucidated thickening of the joints and yellow ligament. CT was also useful for the diagnosis of tumors in the lumbar and sacral spines, visualizing the images of bone changes and soft tissues on the trasverse sections. But the diagnosis of intradural tumors required myelography and metrizamide CT. CT has become important for the diagnosis of spinal and spinal-cord diseases and for selection of the route of surgical arrival. (Chiba, N.)

  16. CT of Mirizzi syndrome

    International Nuclear Information System (INIS)

    Yamamoto, Shinichiro; Fukushima, Keisuke; Ishihara, Kenji; Hirano, Yutaka; Sano, Kaizo

    1983-01-01

    PTC or ERCP findings of four cases of Mirizzi syndrome were demonstrated. They consisted of a smooth stricture of the common hepatic duct, curved impressions of the duct and dilatation of proximal biliary radicles. CT could visualize the impacted stone in the neck of the gallbladder, dilatation of proximal common hepatic and intrahepatic duct. Absence of the dilatation of distal common bile duct could also be confirmed by CT, thus the diagnosis of Mirizzi syndrome might be possible by CT. (author)

  17. CT guided thoracocentesis

    International Nuclear Information System (INIS)

    Shinohara, Yoshitomo; Kobayashi, Kunihiko; Baba, Makoto; Watabe, Hideyuki; Sato, Masashi; Kajiki, Yoshie; Hikita, Fuminori; Yamagishi, Yoshihiko

    1986-01-01

    Our diagnostic method of CT guided thoracocentesis is introduced. This method is especially useful to obtain pleural fluid in patient with small amount of pleural effusion. The essential points of this method are as follows; The course and site to reach the pleural cavity are determined by CT scan. And the angulated 22 G needle is inserted from the back (below) of the supine patient. CT guided thoracocentesis is a simple, safe and sure procedure to obtain pleural fluid. (author)

  18. CT scanning in meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Wardle, Stephan; Carty, Helen (Royal Liverpool Children' s Hospital, Liverpool (United Kingdom). Department of Radiology)

    12 pediatric cases of acute meningitis were reviewed retrospectively. Findings on CT scan were compared with the clinical course and resulting neurological sequelae. Complications detected by CT scanning include subdural effusion, empyema, hydrocephalus, cerebral atrophy, oedema and infarction. The CT scan results adequately correlated with neurological signs in most cases. Infarction was a reliable indicator of neurological sequelae. Cerebral atrophy alone, however, did not correlate well with the clinical sequelae. (author). 19 refs.; 5 figs.; 6 tabs.

  19. CT of pleural abnormalities

    International Nuclear Information System (INIS)

    Webb, W.R.

    1995-01-01

    Briefly discussed were CT diagnosis of pleural thickening, CT technique for examining the pleura or pleuro-pulmonary disease, diagnosis of pleural collections, diagnosis of pleural fluid abnormalities in patients with pneumonia, pleural neoplasms, malignant (diffuse) mesothelioma, metastases, local fibrous tumor of the pleura (benign mesothelioma) (21 refs.)

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may increase the ... or any disorder of the heart, kidneys or thyroid gland , or if you ... brain, including the disease processes) are less visible on CT scans . CT ...

  1. Computed Tomography (CT) -- Head

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    Full Text Available ... diseases than regular radiographs (x-rays). top of page What are some common uses of the procedure? CT ... information about pregnancy and x-rays. top of page What does the equipment look like? The CT scanner ...

  2. Abdominal and Pelvic CT

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    Full Text Available ... benefits of the scan far outweigh any possible risks from the exposure to diagnostic radiation. top of page What are the limitations of CT Scanning of the Abdomen/Pelvis? A person who is very large may not fit into the opening of a conventional CT scanner ...

  3. Abdominal and Pelvic CT

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    Full Text Available ... CT equipment look like? How does the procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of CT Scanning of ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. Abdominal and Pelvic CT

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    Full Text Available ... are very nervous or anxious 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. ...

  8. 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 you some medication to help you tolerate the CT scanning procedure. ...

  9. 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 you some medication to help you tolerate the CT scanning procedure. ...

  10. Abdominal and Pelvic CT

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    Full Text Available ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside of the body. ... often eliminating the need for additional, more invasive diagnostic ... of CT is its ability to image bone, soft tissue and blood vessels all at ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available ... page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different body parts absorb the x-rays ... time. Follow-up examinations are sometimes the best way to see if treatment is working or if a ... conventional x-rays, CT scanning provides very detailed images of many ...

  12. Abdominal and Pelvic CT

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    Full Text Available ... about pregnancy and x-rays. top of page What does the CT equipment look like? The CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the center. You will ...

  13. Abdominal and Pelvic CT

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    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging ...

  14. 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 like other x-ray examinations. Different ... bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging ...

  15. 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 like other x-ray examinations. Different ... bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... stable or changed over time. top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels all at the same time. ...

  17. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... done with low-dose technique. top of page What are the limitations of CT of the Sinuses? CT is usually the first test ordered when a sinus tumor is suspected. If additional information is needed to determine the extent of soft tissue of the tumor, magnetic resonance imaging (MRI) may ...

  18. 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 ...

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

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    Full Text Available ... risks? What are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known ... newborns, infants and older children. top of page What are some common uses of the procedure? CT ...

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

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow new CT scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ...

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

    Medline Plus

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

  2. 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 ...

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

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    Full Text Available ... child for the CT examination. top of page What does the CT equipment look like? The CT scanner is typically a large machine with a hole, or short tunnel, in the center. A moveable ...

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

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    Full Text Available ... beneficial for all patients but especially children, the elderly and critically ill. For some CT exams, a ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  5. 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.)

  6. CT of intrahepatic lithiasis

    International Nuclear Information System (INIS)

    Regge, D.; Debernardi, S.; Kienle, S.; Martina, M.C.; Biselli, S.; Gandini, G.

    1992-01-01

    Twenty out of 65 patients, submitted to percutaneous treatment for intrahepatic stones at our department since 1983, had ultrasound (US) and computed tomography (CT) performed before any treatment. CT visualised stones in 65% of patients while distribution of stones was assessed correctly in 40%. In 5 patients CT provided information useful for treatment: in one case extremely dilated bile ducts hindered cholangiographic evaluation of lithiasis while in the other four cases CT examinations showed stones in dilated bile ducts unrecognised on percutaneous or endoscopic retrograde cholangiography. It is concluded that CT is a useful tool in the diagnosis of bile duct lithiasis. It aids in treatment selection and, when the percutaneous approach is chosen, allows the interventional radiologist to select the ducts to be catheterised. (orig.)

  7. CT of intrahepatic lithiasis

    Energy Technology Data Exchange (ETDEWEB)

    Regge, D. [Ist. di Radiologia, Univ. di Torino, Torino (Italy); Debernardi, S. [Ist. di Radiologia, Univ. di Torino, Torino (Italy); Kienle, S. [Ist. di Radiologia, Univ. di Torino, Torino (Italy); Martina, M.C. [Ist. di Radiologia, Univ. di Torino, Torino (Italy); Biselli, S. [Ist. di Radiologia, Univ. di Torino, Torino (Italy); Gandini, G. [Ist. di Radiologia, Univ. di Torino, Torino (Italy)

    1992-12-01

    Twenty out of 65 patients, submitted to percutaneous treatment for intrahepatic stones at our department since 1983, had ultrasound (US) and computed tomography (CT) performed before any treatment. CT visualised stones in 65% of patients while distribution of stones was assessed correctly in 40%. In 5 patients CT provided information useful for treatment: in one case extremely dilated bile ducts hindered cholangiographic evaluation of lithiasis while in the other four cases CT examinations showed stones in dilated bile ducts unrecognised on percutaneous or endoscopic retrograde cholangiography. It is concluded that CT is a useful tool in the diagnosis of bile duct lithiasis. It aids in treatment selection and, when the percutaneous approach is chosen, allows the interventional radiologist to select the ducts to be catheterised. (orig.)

  8. Head trauma and CT

    International Nuclear Information System (INIS)

    Samejima, Kanji; Yoshii, Nobuo; Tobari, Chitoshi

    1979-01-01

    In our cases of acute and subacute subdural hematoma, the use of CT was evaluated. In our department of surgery, acute subdural hematoma was found in 46 of 388 patients of head trauma who underwent CT. Acute subdural hematoma, like epidural hematoma was usually visualized as a high-density area along the cranial inner table, and this was easily differenciated from epidural hematoma because of difference in shape from the other. The picture of acute subdural hematoma was occasionally confused with that of intracerebral hematoma or cerebral contusion. Single use of CT does not differenciate subacute subdural hematoma from chronic subdural hematoma. However, CT usually visualized acute hematoma as a high-density area, showing the extent of hematoma. Comparison of the thickness of hematoma with the axis deviation of the median part such as the 3rd cerebral ventricle suggested severity of cerebral edema. CT also revealed bilateral or multiple lesions of cerebral contusion or intracerebral hematoma. (Ueda, J.)

  9. CT of tracheal agenesis

    International Nuclear Information System (INIS)

    Strouse, Peter J.; Hernandez, Ramiro J.; Newman, Beverley

    2006-01-01

    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.)

  10. CT of the heart

    International Nuclear Information System (INIS)

    Lipton, M.J.

    1986-01-01

    Advances based upon the detector elements instead of X-ray film have greatly increased the power of X-ray imaging. Computed tomography (CT) creates cross sectional rather than projected images. Recently, high speed CT devices have been developed for cardiovascular studies. The Cine-CT scanner employs a scanning electron beam deflected on an extended tungsten target ring. Fast scans of 50 millisecond exposures at multiple levels can provide information concerning blood flow in vessels and tissues, myocardial wall motion, valve integrity, coronary bypass graft patency and proximal coronary artery anatomy. Cine-CT dynamic scanning can also provide volume imaging with small quantities (0.05 - 1.5 ml/kg) of contrast medium administered via peripheral vein injections. Cine-CT provides simultaneous measurements of cardiac dimensions and function and is rapidly becoming a new tool for quantitating myocardial blood flow, cardiac chamber volumes and wall mechanics. The future outlook is very promising for this three-dimensional cine-CT technique with high spatial resolution. High speed CT should provide unique diagnostic information and as the technology continues to improve at a rapid speed, this new imaging modality could be a challenge for angiography. (Auth.)

  11. Abdominal and Pelvic CT

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    Full Text Available ... objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and should be left at ... of the examination the same way that it affects photographs. If contrast material is used, depending on ...

  12. Computed Tomography (CT) -- Head

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    Full Text Available ... objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and should be left at ... of the examination the same way that it affects photographs. If contrast material is used, depending on ...

  13. 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 ... hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to ...

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... small amount of radiation is aimed at and passes through the part of the body being examined, ... of CT scan, the machine may make several passes. You may be asked to hold your breath ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... small amount of radiation is aimed at and passes through the part of the body being examined, ... of CT scan, the machine may make several passes. You may be asked to hold your breath ...

  16. Abdominal and Pelvic CT

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    Full Text Available ... small amount of radiation is aimed at and passes through the part of the body being examined, ... of CT scan, the machine may make several passes. You may be asked to hold your breath ...

  17. 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 ...

  18. 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 ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... may increase the risk of an unusual adverse effect. The radiologist also should know if you have ... to urinate; however, this is actually a contrast effect and subsides quickly. When you enter the CT ...

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    Full Text Available ... may increase the risk of an unusual adverse effect. Women should always inform their physician and the ... to urinate; however, this is actually a contrast effect and subsides quickly. When you enter the CT ...

  1. 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 ... deal with them. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  2. 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 ... in the womb. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these ... allows the body parts to be distinguished from one another on an x-ray film or CT ...

  4. Abdominal and Pelvic CT

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    Full Text Available ... you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these ... allows the body parts to be distinguished from one another on an x-ray film or CT ...

  5. 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 ... membranes covering the brain. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Brain ...

  6. 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 the moving table. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Head ...

  7. Computed Tomography (CT) -- Head

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

  8. Computed Tomography (CT) -- Sinuses

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

  9. 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 ...

  10. 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 ...

  11. Abdominal and Pelvic CT

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    Full Text Available ... CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder Cancer Radiation ... To locate a medical imaging or radiation oncology provider in your community, you can search the ACR- ...

  12. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... have special pediatric considerations. 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 ...

  13. Computed Tomography (CT) -- Sinuses

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

  14. 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 ...

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  16. 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 ... very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. ...

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    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT ... very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. ...

  18. 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 ... very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. ...

  19. 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 ... the best way to see if treatment is working or if a finding is stable or changed ...

  20. 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 ... the best way to see if treatment is working or if a finding is stable or changed ...

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ... may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body ...

  2. Abdominal and Pelvic CT

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

  3. Computed Tomography (CT) -- Head

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

  4. 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 ...

  5. 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 ... imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ...

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    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ...

  7. Abdominal and Pelvic CT

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

  8. Abdominal and Pelvic CT

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    Full Text Available ... injuries and bleeding quickly enough to help save lives. Tell your doctor if there’s a possibility you ... injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost- ...

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    Full Text Available ... injuries and bleeding quickly enough to help save lives. Tell your doctor if there’s a possibility you ... injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost- ...

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    Full Text Available ... allows the body parts to be distinguished from one another on an x-ray film or CT ... entire body will be "inside" the scanner at one time such as with MRI. If an intravenous ...

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    Full Text Available Toggle navigation ... the paranasal sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the nasal cavity. CT scanning is painless, noninvasive ...

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    Full Text Available ... technique called Perfusion CT. brain tumors. enlarged brain cavities (ventricles) in patients with hydrocephalus . diseases or malformations ... are present in the paranasal sinuses. plan radiation therapy for cancer of the brain or other tissues. ...

  13. Computed Tomography (CT) -- Head

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    Full Text Available ... of a stroke. a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain cavities (ventricles) in patients with hydrocephalus . diseases or malformations ...

  14. 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 ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

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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 ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  16. 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 ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  17. Computed Tomography (CT) - Spine

    Science.gov (United States)

    ... the removal of fluid from a localized infection ( abscess ). In patients with narrowing ( stenosis ) of the spine ... Survey Images × Image Gallery Computed Tomography (CT or CAT scan) equipment View full size with caption Do ...

  18. Pelvic CT scan

    Science.gov (United States)

    CAT scan - pelvis; Computed axial tomography scan - pelvis; Computed tomography scan - pelvis; CT scan - pelvis ... Abnormal results may be due to: Abscess (collection of pus) Bladder stones Broken bone Cancer Diverticulitis

  19. 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 ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  2. Abdominal and Pelvic CT

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  3. Abdominal and Pelvic CT

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    Full Text Available ... seconds, and even faster in small children. Such speed is beneficial for all patients but especially children, ... pain is caused by infection and inflammation, the speed, ease and accuracy of a CT examination can ...

  4. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... openings. top of page What are some common uses of the procedure? CT of the sinuses is ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ...

  5. Computed Tomography (CT) -- Head

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    Full Text Available ... rays). top of page What are some common uses of the procedure? CT scanning of the head ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams ... or your insurance provider to get a better understanding of the possible charges you will incur. Web ...

  7. 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, ...

  8. 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, ...

  9. 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, ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... pictures of the inside of the body. The cross-sectional images generated during a CT scan can ... large volume of data to create two-dimensional cross-sectional images of your body, which are then ...

  11. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... pictures of the inside of the body. The cross-sectional images generated during a CT scan can ... large volume of data to create two-dimensional cross-sectional images of your body, which are then ...

  12. Abdominal and Pelvic CT

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    Full Text Available ... pictures of the inside of the body. The cross-sectional images generated during a CT scan can ... large volume of data to create two-dimensional cross-sectional images of your body, which are then ...

  13. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... many areas of the body, particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a ...

  14. Abdominal and Pelvic CT

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    Full Text Available ... slices. 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 ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... slices. 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 ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... slices. 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 ...

  17. 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 ...

  18. 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 ...

  19. 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 ...

  20. Abdominal and Pelvic CT

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

  1. Abdominal and Pelvic CT

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    Full Text Available ... DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. top of page What are some common ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... can lead to artifacts on the images. This loss of image quality can resemble the blurring seen ... advantage of CT is its ability to image bone, soft tissue and blood vessels all at the ...

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... can lead to artifacts on the images. This loss of image quality can resemble the blurring seen ... advantage of CT is its ability to image bone, soft tissue and blood vessels all at the ...

  4. Abdominal and Pelvic CT

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    Full Text Available ... can lead to artifacts on the images. This loss of image quality can resemble the blurring seen ... advantage of CT is its ability to image bone, soft tissue and blood vessels all at the ...

  5. 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 ...

  6. Abdominal and Pelvic CT

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    Full Text Available ... treatments. plan for and assess the results of surgery, such as organ transplants. stage, plan and properly ... CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a ...

  7. Computed Tomography (CT) -- Sinuses

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

  8. CT urography and hematuria

    DEFF Research Database (Denmark)

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

    2015-01-01

    BACKGROUND: Computed tomography (CT) urography is now used in the work-up of patients with hematuria. The dose of contrast medium and radiation varies considerably between the different CT protocols. PURPOSE: To study the disease prevalence in a consecutive group of patients with hematuria...... undergoing CT urography with a low dose of contrast medium and radiation. MATERIAL AND METHODS: From 1 April 2007 to 31 March 2008, using the Radiological Information System (RIS) as well as electronic patient records, demographic data, reason for referral, and diagnosis were obtained for all patients...... or complex cyst was found in the kidneys or the ureters in patients with nonvisible hematuria. CONCLUSION: CT urography with its low dose of contrast medium and radiation is a useful diagnostic imaging test for investigating patients with hematuria....

  9. 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 ... will hear only slight buzzing, clicking and whirring sounds as the CT scanner's internal parts, not usually ...

  10. 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 ... will hear only slight buzzing, clicking and whirring sounds as the CT scanner's internal parts, not usually ...

  11. 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 ... will hear only slight buzzing, clicking and whirring sounds as the CT scanner's internal parts, not usually ...

  12. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... artifacts on the images. This loss of image quality can resemble the blurring seen on a photograph ... verifies that the images are of high enough quality for accurate interpretation. The actual CT scan takes ...

  13. Abdominal and Pelvic CT

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

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate the need ... to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. The effective radiation dose ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by CT scanning may eliminate the need ... to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. The effective radiation dose ...

  16. Abdominal and Pelvic CT

    Science.gov (United States)

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

  17. Computed Tomography (CT) -- Sinuses

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

  18. Computed Tomography (CT) -- Head

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

  19. Abdominal and Pelvic CT

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

  20. Computed Tomography (CT) -- Sinuses

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

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... up in shades of gray, and air appears black. With CT scanning, numerous x-ray beams and ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  2. Abdominal and Pelvic CT

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    Full Text Available ... up in shades of gray, and air appears black. With CT scanning, numerous x-ray beams and ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  3. Computed Tomography (CT) -- Head

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    Full Text Available ... up in shades of gray, and air appears black. With CT scanning, numerous x-ray beams and ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. 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 ... hard time staying still, are claustrophobic, or have chronic pain, you may find a CT exam to ...

  8. 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 ... hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to ...

  9. 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 ... still, are very nervous or anxious or have chronic pain, you may find a CT exam to ...

  10. Abdominal and Pelvic CT

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    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Viewing a CT scan, an experienced radiologist can ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. A ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  12. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits A CT scan is one of the safest ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  13. 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 ...

  14. 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 ...

  15. 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 ...

  16. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... openings. top of page What are some common uses of the procedure? CT of the sinuses is ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ...

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    Full Text Available ... rays). top of page What are some common uses of the procedure? CT scanning of the head ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ...

  18. 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 ...

  19. 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 ...

  20. Abdominal and Pelvic CT

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