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Richard J Choi - One of the best experts on this subject based on the ideXlab platform.
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quantitative assessment of colon distention for polyp detection in ct Virtual Colonoscopy
Medical Imaging 2006: Physiology Function and Structure from Medical Images, 2006Co-Authors: Robert Legrand Van Uitert, M Ronald M D Summers, Ingmar Bitter, Richard J Choi, J Perry M D PickhardtAbstract:Virtual Colonoscopy is becoming a more prevalent way to diagnose colon cancer. One of the critical elements in detecting cancerous polyps using Virtual Colonoscopy, especially in conjunction with computer-aided detection of polyps, is that the colon be sufficiently distended. We have developed an automatic method to determine from a CT scan what percentage of the colon is distended by 1cm or larger and compared our method with a radiologist's assessment of quality of the scan with respect to successful colon polyp detection. A radiologist grouped 41 CT Virtual Colonoscopy scans into three groups according to the degree of colonic distention, "well", "medium", and "poor". We also employed a subvoxel accurate centerline algorithm and a subvoxel accurate distance transform to each dataset to measure the colon distention along the centerline. To summarize the colonic distention with a single value relevant for polyp detection, the distention score, we recorded the percentage of centerline positions in which the colon distention was 1cm or larger. We then compared the radiologist's assessment and the computed results. The sorting of all datasets according to the distention score agreed with the radiologist's assessment. The "poor" cases had a mean and standard deviation score of 78.4% ± 5.2%, the "medium" cases measured 88.7% ± 1.9%, and the "well" cases 98.8% ± 1.5%. All categories were shown to be significantly different from each other using unpaired two sample t-tests. The presented colonic distention score is an accurate method for assessing the quality of colonic distention for CT colonography.
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computed tomographic Virtual Colonoscopy computer aided polyp detection in a screening population
Gastroenterology, 2005Co-Authors: Ronald M Summers, Ingmar Bitter, Richard J Choi, Perry J Pickhardt, Jianhua Yao, Marek Franaszek, Daniel Brickman, Vamsi KrishnaAbstract:Background & Aims: The sensitivity of computed tomographic (CT) Virtual Colonoscopy (CT colonography) for detecting polyps varies widely in recently reported large clinical trials. Our objective was to determine whether a computer program is as sensitive as optical Colonoscopy for the detection of adenomatous colonic polyps on CT Virtual Colonoscopy. Methods: The data set was a cohort of 1186 screening patients at 3 medical centers. All patients underwent same-day Virtual and optical Colonoscopy. Our enhanced gold standard combined segmental unblinded optical Colonoscopy and retrospective identification of precise polyp locations. The data were randomized into separate training (n = 394) and test (n = 792) sets for analysis by a computer-aided polyp detection (CAD) program. Results: For the test set, per-polyp and per-patient sensitivities for CAD were both 89.3% (25/28; 95% confidence interval, 71.8%–97.7%) for detecting retrospectively identifiable adenomatous polyps at least 1 cm in size. The false-positive rate was 2.1 (95% confidence interval, 2.0–2.2) false polyps per patient. Both carcinomas were detected by CAD at a false-positive rate of 0.7 per patient; only 1 of 2 was detected by optical Colonoscopy before segmental unblinding. At both 8-mm and 10-mm adenoma size thresholds, the per-patient sensitivities of CAD were not significantly different from those of optical Colonoscopy before segmental unblinding. Conclusions: The per-patient sensitivity of CT Virtual Colonoscopy CAD in an asymptomatic screening population is comparable to that of optical Colonoscopy for adenomas ≥8 mm and is generalizable to new CT Virtual Colonoscopy data.
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flat colorectal lesions in asymptomatic adults implications for screening with ct Virtual Colonoscopy
American Journal of Roentgenology, 2004Co-Authors: Perry J Pickhardt, Richard J Choi, Pamela A Nugent, William R SchindlerAbstract:OBJECTIVE. The clinical significance of flat lesions in colorectal cancer screening remains uncertain. The purpose of this study was to investigate the frequency, histology, and Virtual Colonoscopy detection of flat lesions in an asymptomatic screening population.SUBJECTS AND METHODS. The morphology of all detected polyps was prospectively recorded as flat or polypoid (sessile or pedunculated) in 1,233 consecutive asymptomatic adults who underwent same-day Virtual Colonoscopy and optical Colonoscopy. A flat morphology was defined as a shallow plaquelike broad-based lesion with a height of less than one half of its width.RESULTS. Of 344 polyps of 6 mm or greater confirmed at optical Colonoscopy, 17 (4.9%) were labeled as flat at both Virtual Colonoscopy and optical Colonoscopy; 17 (4.9%), at optical Colonoscopy only; and 25 (7.3%), at Virtual Colonoscopy only, yielding 59 total lesions in 52 (4.2%) of 1,233 patients. Twenty-nine (49.2%) of 59 flat lesions were adenomatous, of which four measured 10 mm or g...
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computed tomographic Virtual Colonoscopy to screen for colorectal neoplasia in asymptomatic adults
The New England Journal of Medicine, 2003Co-Authors: Perry J Pickhardt, Richard J Choi, Inku Hwang, James Butler, Michael L Puckett, Hans A Hildebrandt, Roy K H Wong, Pamela A Nugent, Pauline A Mysliwiec, William R SchindlerAbstract:background We evaluated the performance characteristics of computed tomographic (CT) Virtual Colonoscopy for the detection of colorectal neoplasia in an average-risk screening population. methods A total of 1233 asymptomatic adults (mean age, 57.8 years) underwent same-day Virtual and optical Colonoscopy. Radiologists used the three-dimensional endoluminal display for the initial detection of polyps on CT Virtual Colonoscopy. For the initial examination of each colonic segment, the colonoscopists were unaware of the findings on Virtual Colonoscopy, which were revealed to them before any subsequent reexamination. The sensitivity and specificity of Virtual Colonoscopy and the sensitivity of optical Colonoscopy were calculated with the use of the findings of the final, unblinded optical Colonoscopy as the reference standard. results The sensitivity of Virtual Colonoscopy for adenomatous polyps was 93.8 percent for polyps at least 10 mm in diameter, 93.9 percent for polyps at least 8 mm in diameter, and 88.7 percent for polyps at least 6 mm in diameter. The sensitivity of optical Colonoscopy for adenomatous polyps was 87.5 percent, 91.5 percent, and 92.3 percent for the three sizes of polyps, respectively. The specificity of Virtual Colonoscopy for adenomatous polyps was 96.0 percent for polyps at least 10 mm in diameter, 92.2 percent for polyps at least 8 mm in diameter, and 79.6 percent for polyps at least 6 mm in diameter. Two polyps were malignant; both were detected on Virtual Colonoscopy, and one of them was missed on optical Colonoscopy before the results on Virtual Colonoscopy were revealed. conclusions CT Virtual Colonoscopy with the use of a three-dimensional approach is an accurate screening method for the detection of colorectal neoplasia in asymptomatic averagerisk adults and compares favorably with optical Colonoscopy in terms of the detection of clinically relevant lesions.
J T Ferrucci - One of the best experts on this subject based on the ideXlab platform.
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consensus on current clinical practice of Virtual Colonoscopy
American Journal of Roentgenology, 2005Co-Authors: M. A. Barish, Jorge A Soto, J T FerrucciAbstract:OBJECTIVE. The purpose of our study was to determine the current opinions regarding the performance, interpretation, reporting, and clinical role of Virtual Colonoscopy among a group of selected experts to develop a consensus statement.MATERIALS AND METHODS. A questionnaire was sent to 33 selected experts in Virtual Colonoscopy. Responses were tabulated and results were used to develop a consensus statement. The results of the questionnaire and consensus statement were sent to respondents for comment and approval.RESULTS. Thirty-one (93.9%) of 33 surveys were returned. Eighty-seven percent (27/31) of respondents believe Virtual Colonoscopy is a credible screening method. Oral sodium phosphate solution is the laxative preferred by more than 66% (18/27), whereas 62% (13/21) do not believe fecal tagging is necessary. All respondents (25/25) think that both prone and supine imaging is required, with most (81%, 21/26) believing IV contrast material is not necessary. The routine use of spasmolytics is suggested...
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colon cancer screening with Virtual Colonoscopy promise polyps politics
American Journal of Roentgenology, 2001Co-Authors: J T FerrucciAbstract:: Virtual Colonoscopy (CT colonography) promises to become a primary method for colorectal cancer screening and return radiologists to a major role in colon cancer prevention. Results from major centers in the United States show accuracy to be comparable to conventional Colonoscopy for detection of polyps of significant size--that is, greater than 10 mm--with few false-positives. The advent of Virtual Colonoscopy has also heightened awareness of the natural history of colonic polyps, particularly in terms of identifying an appropriate target size for detection in colorectal screening programs. Small polyps (<10 mm) are often either hyperplastic on histology or are unlikely to progress to frank cancer in the patient's lifetime and are therefore of little clinical significance for the average adult. Thus, the rationale for detecting and removing each and every colonic polyp regardless of size has come under increasing scrutiny in the context of cost-benefit analysis of various test strategies for colorectal cancer screening. Virtual Colonoscopy may allow patients to obtain reliable information about the status of their colonic mucosa noninvasively and thus make a more informed decision as to whether to proceed to conventional Colonoscopy for polypectomy.
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first international symposium on Virtual Colonoscopy
American Journal of Roentgenology, 1999Co-Authors: Helen M. Fenlon, J T FerrucciAbstract:R esults of almost 1000 Virtual colonoscopic examinations were presented at the First International Symposium on Virtual Colonoscopy in Boston, MA, October 1-2, 1998. The data prosented indicated that the performance of Virtual Colonoscopy for detection of colonic polyps and cancer approaches that of conventional Colonoscopy and exceeds that of barium enema. At present, only a small number of academic centers have achieved this level of success despite considerable expenditure in physician time. Technical developments in image acquisition, data postprocessing, and workstation analysis are expected to improve performance and reduce interpretative times in the future. Rapidly widening clinical applications of this technique for colorectal evaluation were projected. The two-day multidisciplinary symposium was jointly hosted by Boston University (director, Joseph T. Ferrucci; codirector, Helen M. Fenlon) and Stanford University (codirector, R. Brooke Jeffrey, Jr.). The American Cancer Society (ACS) served as cosponsor. ACS President David Rosenthal, of Boston, opened the meeting, and ACS Past-President Gerald D. Dodd, Jr., of Houston, TX, was named Honorary President of the symposium. Twenty-one invited faculty-including radiologists, gastroenterologists, and epidemiologists-and government representatives, presenters of free papers, scientific exhibitors, commercial vendors, and more than 120 registrants attended the meeting; twelve countries were represented. The principal goals of the symposium were to share current results and research initiatives and achieve consensus on the means by which to evaluate Virtual Colonoscopy as a screening technique for colorectal cancer. Although controversy about terminology exists, participants at the symposium accepted the use of “Virtual Colonoscopy” as a satisfactory interim designation for the imaging technique until agreement is reached on a more precise and scientific description.
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occlusive colon carcinoma Virtual Colonoscopy in the preoperative evaluation of the proximal colon
Radiology, 1999Co-Authors: Helen M. Fenlon, David Nunes, P D Clarke, David Mcaneny, J T FerrucciAbstract:PURPOSE: To evaluate the use of preoperative Virtual Colonoscopy to examine the proximal colon in patients with distal occlusive carcinomas, defined as cancers that cannot be traversed endoscopically. MATERIALS AND METHODS: Twenty-nine patients with occlusive colorectal carcinomas underwent preoperative Virtual Colonoscopy with use of a standard protocol. Patients with acute bowel obstruction were excluded. Results of Virtual Colonoscopy were compared with the findings of preoperative Colonoscopy, preoperative barium enema examination, intraoperative colon palpation, histopathologic outcome, and postoperative Colonoscopy and barium enema examination, where possible. RESULTS: Virtual Colonoscopy helped identify all 29 occlusive carcinomas and demonstrated two cancers and 24 polyps in the proximal colon. Both synchronous cancers were confirmed intraoperatively and resected. Postoperative conventional Colonoscopy in 12 patients confirmed 16 polyps identified at Virtual Colonoscopy and demonstrated two subcen...
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colorectal neoplasm detection using Virtual Colonoscopy a feasibility study
Gut, 1998Co-Authors: Helen M. Fenlon, David Nunes, P D Clarke, J T FerrucciAbstract:Background—Virtual Colonoscopy is a potentially powerful tool for non-invasive colorectal evaluation. In vitro studies have established its accuracy in simulated polyp detection but little data exist regarding its use in clinical practice. Aims—To evaluate the ability of Virtual Colonoscopy to detect colorectal cancers and polyps in patients with endoscopically proven colorectal neoplasms and to correlate the findings of Virtual Colonoscopy with those of conventional Colonoscopy, surgery, and histopathology. Patients—Thirty eight patients with endoscopic findings suggestive of colorectal carcinoma. Methods—Virtual Colonoscopy was performed using thin section helical computed tomography (CT) of the abdomen and pelvis after rectal insufflation of room air. Commercially available software was used to generate endoscopic "fly through" examinations of the colon from the CT data. Results were correlated with the findings of conventional Colonoscopy and with the surgical and histopathological outcome in each case. Results—Thirty eight pathologically proven colorectal cancers and 23 adenomatous polyps were present. On Virtual Colonoscopy, all cancers and all polyps measuring greater than 6 mm in size were identified; there were two false positive reports of polyps. On conventional Colonoscopy, there was one false positive report of a malignant sigmoid stricture; four subcentimetre polyps were overlooked. Virtual Colonoscopy enabled visualisation of the entire colon in 35 patients; conventional Colonoscopy was incomplete in 14 patients. Virtual Colonoscopy correctly localised all 38cancers, compared with 32 using conventional Colonoscopy. Conclusion—Virtual Colonoscopy is a feasible method for evaluating the colon; it may have role in diagnosis of colorectal cancer and polyps. Keywords: colonic neoplasms; computed tomography; computer simulation
Ingmar Bitter - One of the best experts on this subject based on the ideXlab platform.
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quantitative assessment of colon distention for polyp detection in ct Virtual Colonoscopy
Medical Imaging 2006: Physiology Function and Structure from Medical Images, 2006Co-Authors: Robert Legrand Van Uitert, M Ronald M D Summers, Ingmar Bitter, Richard J Choi, J Perry M D PickhardtAbstract:Virtual Colonoscopy is becoming a more prevalent way to diagnose colon cancer. One of the critical elements in detecting cancerous polyps using Virtual Colonoscopy, especially in conjunction with computer-aided detection of polyps, is that the colon be sufficiently distended. We have developed an automatic method to determine from a CT scan what percentage of the colon is distended by 1cm or larger and compared our method with a radiologist's assessment of quality of the scan with respect to successful colon polyp detection. A radiologist grouped 41 CT Virtual Colonoscopy scans into three groups according to the degree of colonic distention, "well", "medium", and "poor". We also employed a subvoxel accurate centerline algorithm and a subvoxel accurate distance transform to each dataset to measure the colon distention along the centerline. To summarize the colonic distention with a single value relevant for polyp detection, the distention score, we recorded the percentage of centerline positions in which the colon distention was 1cm or larger. We then compared the radiologist's assessment and the computed results. The sorting of all datasets according to the distention score agreed with the radiologist's assessment. The "poor" cases had a mean and standard deviation score of 78.4% ± 5.2%, the "medium" cases measured 88.7% ± 1.9%, and the "well" cases 98.8% ± 1.5%. All categories were shown to be significantly different from each other using unpaired two sample t-tests. The presented colonic distention score is an accurate method for assessing the quality of colonic distention for CT colonography.
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computed tomographic Virtual Colonoscopy computer aided polyp detection in a screening population
Gastroenterology, 2005Co-Authors: Ronald M Summers, Ingmar Bitter, Richard J Choi, Perry J Pickhardt, Jianhua Yao, Marek Franaszek, Daniel Brickman, Vamsi KrishnaAbstract:Background & Aims: The sensitivity of computed tomographic (CT) Virtual Colonoscopy (CT colonography) for detecting polyps varies widely in recently reported large clinical trials. Our objective was to determine whether a computer program is as sensitive as optical Colonoscopy for the detection of adenomatous colonic polyps on CT Virtual Colonoscopy. Methods: The data set was a cohort of 1186 screening patients at 3 medical centers. All patients underwent same-day Virtual and optical Colonoscopy. Our enhanced gold standard combined segmental unblinded optical Colonoscopy and retrospective identification of precise polyp locations. The data were randomized into separate training (n = 394) and test (n = 792) sets for analysis by a computer-aided polyp detection (CAD) program. Results: For the test set, per-polyp and per-patient sensitivities for CAD were both 89.3% (25/28; 95% confidence interval, 71.8%–97.7%) for detecting retrospectively identifiable adenomatous polyps at least 1 cm in size. The false-positive rate was 2.1 (95% confidence interval, 2.0–2.2) false polyps per patient. Both carcinomas were detected by CAD at a false-positive rate of 0.7 per patient; only 1 of 2 was detected by optical Colonoscopy before segmental unblinding. At both 8-mm and 10-mm adenoma size thresholds, the per-patient sensitivities of CAD were not significantly different from those of optical Colonoscopy before segmental unblinding. Conclusions: The per-patient sensitivity of CT Virtual Colonoscopy CAD in an asymptomatic screening population is comparable to that of optical Colonoscopy for adenomas ≥8 mm and is generalizable to new CT Virtual Colonoscopy data.
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Virtual Colonoscopy
Communications of The ACM, 2005Co-Authors: Arie E. Kaufman, Sarang Lakare, Kevin Kreeger, Ingmar BitterAbstract:A computer-graphics-based alternative to conventional optical Colonoscopy, known as Virtual Colonoscopy (VC) or computed tomography colonography (CTC), is rapidly gaining popularity. During this procedure, which was concurrently developed by our group at Stony Brook University [5] and by other researchers [10], the distended colon is imaged by a helical or multislice CT scanner. The acquired abdominal CT scan commonly consists of 350--750 axial images of 512x512 sub-millimeter resolution, providing excellent contrast between the colon wall and the lumen. A 3D model of the colon is then reconstructed from the CT scan by automatically segmenting the colon out of the rest of the abdomen and employing an electronic cleansing algorithm for computer-based removal of the residual material. The PC-based visualization software employs volume rendering and allows the user, typically a physician, to interactively navigate through the Virtual 3D model of the colon. An intuitive user interface with customized tools supports measurements and Virtual biopsy to inspect suspicious regions. Unlike optical Colonoscopy (see the sidebar "Conventional Colorectal Cancer Screening"), VC is patient friendly since the patient undergoes less rigorous preparation prior to the procedure. VC is also a fast, noninvasive, highly accurate, cost-effective method for mass screening of colon polyps.
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automatic centerline extraction for Virtual Colonoscopy
IEEE Transactions on Medical Imaging, 2002Co-Authors: Zhengrong Liang, Ingmar Bitter, Lichan Hong, Qi Ke, Arie E. KaufmanAbstract:In this paper, we introduce a concise and concrete definition of an accurate colon centerline and provide an efficient automatic means to extract the centerline and its associated branches (caused by a forceful touching of colon and small bowel or a deep fold in twisted colon lumen). We further discuss its applications on fly-through path planning and endoscopic simulation, as well as its potential to solve the challenging touching and colon collapse problems in Virtual Colonoscopy. Experimental results demonstrated its centeredness, robustness, and efficiency.
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3d Virtual Colonoscopy with real time volume rendering
Medical Imaging 2000: Physiology and Function from Multidimensional Images, 2000Co-Authors: Wei Jian Li, Ingmar Bitter, Zhengrong Liang, Arie E. Kaufman, Kevin Kreeger, Dongqing ChenAbstract:In our previous work, we developed a Virtual Colonoscopy system on a high-end 16-processor SGI Challenge with an expensive hardware graphics accelerator. The goal of this work is to port the system to a low cost PC in order to increase its availability for mass screening. Recently, Mitsubishi Electric has developed a volume-rendering PC board, called VolumePro, which includes 128 MB of RAM and vg500 rendering chip. The vg500 chip, based on Cube-4 technology, can render a 256 3 volume at 30 frames per second. High image quality of volume rendering inside the colon is guaranteed by the full lighting model and 3D interpolation supported by the vg500 chip. However, the VolumePro board is lacking some features required by our interactive colon navigation. First, VolumePro currently does not support perspective projection which is paramount for interior colon navigation. Second, the patient colon data is usually much larger than 256 3 and cannot be rendered in real-time. In this paper, we present our solutions to these problems, including simulated perspective projection and axis aligned boxing techniques, and demonstrate the high performance of our Virtual Colonoscopy system on low cost PCs.
Helen M. Fenlon - One of the best experts on this subject based on the ideXlab platform.
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Virtual Colonoscopy and colorectal cancer screening
Abdominal Imaging, 2000Co-Authors: A S Chaoui, Michael A. Blake, M. A. Barish, Helen M. FenlonAbstract:Colorectal cancer (CRC) is the leading cause of cancer related death in the United States. Virtual Colonoscopy is a new method for imaging the colon and has produced promising early results for polyp and cancer detection. The challenge remains to reproduce these favorable results in clinical practice and to evaluate the use of Virtual Colonoscopy in a purely screening population. Virtual Colonoscopy may dramatically improve population participation in screening programs and play a major role in minimizing the impact of CRC.
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Science, medicine, and the future: Virtual Colonoscopy
BMJ, 1999Co-Authors: Steve Halligan, Helen M. FenlonAbstract:Virtual Colonoscopy is a new procedure that fuses computed tomography of the large bowel with advanced techniques for rendering three dimensional images to produce views of the colonic mucosa similar to those obtained during “real” Colonoscopy. Preliminary results suggest that it surpasses barium enema and approaches the sensitivity of conventional Colonoscopy. This review summarises the technical developments that have made Virtual Colonoscopy possible and describes the expected advantages of this exciting technique over conventional endoscopy and more traditional imaging methods. We describe its possible applications and outline further technical developments that can be expected in the near future.
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Virtual Colonoscopy--technique and applications.
Italian Journal of Gastroenterology and Hepatology, 1999Co-Authors: Helen M. Fenlon, M. A. Barish, Joseph T. FerrucciAbstract:: Virtual Colonoscopy is a new method for evaluating the colon which uses thin section computed tomography of the clean air distended colon. The acquired computed tomography data is then subjected to computer manipulation to demonstrate the colonic mucosa. It is a safe, non-invasive, well-tolerated method that has potential as a method of colorectal cancer screening. This review will describe the technique, review preliminary results, and discuss the present and future applications of this technique.
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first international symposium on Virtual Colonoscopy
American Journal of Roentgenology, 1999Co-Authors: Helen M. Fenlon, J T FerrucciAbstract:R esults of almost 1000 Virtual colonoscopic examinations were presented at the First International Symposium on Virtual Colonoscopy in Boston, MA, October 1-2, 1998. The data prosented indicated that the performance of Virtual Colonoscopy for detection of colonic polyps and cancer approaches that of conventional Colonoscopy and exceeds that of barium enema. At present, only a small number of academic centers have achieved this level of success despite considerable expenditure in physician time. Technical developments in image acquisition, data postprocessing, and workstation analysis are expected to improve performance and reduce interpretative times in the future. Rapidly widening clinical applications of this technique for colorectal evaluation were projected. The two-day multidisciplinary symposium was jointly hosted by Boston University (director, Joseph T. Ferrucci; codirector, Helen M. Fenlon) and Stanford University (codirector, R. Brooke Jeffrey, Jr.). The American Cancer Society (ACS) served as cosponsor. ACS President David Rosenthal, of Boston, opened the meeting, and ACS Past-President Gerald D. Dodd, Jr., of Houston, TX, was named Honorary President of the symposium. Twenty-one invited faculty-including radiologists, gastroenterologists, and epidemiologists-and government representatives, presenters of free papers, scientific exhibitors, commercial vendors, and more than 120 registrants attended the meeting; twelve countries were represented. The principal goals of the symposium were to share current results and research initiatives and achieve consensus on the means by which to evaluate Virtual Colonoscopy as a screening technique for colorectal cancer. Although controversy about terminology exists, participants at the symposium accepted the use of “Virtual Colonoscopy” as a satisfactory interim designation for the imaging technique until agreement is reached on a more precise and scientific description.
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occlusive colon carcinoma Virtual Colonoscopy in the preoperative evaluation of the proximal colon
Radiology, 1999Co-Authors: Helen M. Fenlon, David Nunes, P D Clarke, David Mcaneny, J T FerrucciAbstract:PURPOSE: To evaluate the use of preoperative Virtual Colonoscopy to examine the proximal colon in patients with distal occlusive carcinomas, defined as cancers that cannot be traversed endoscopically. MATERIALS AND METHODS: Twenty-nine patients with occlusive colorectal carcinomas underwent preoperative Virtual Colonoscopy with use of a standard protocol. Patients with acute bowel obstruction were excluded. Results of Virtual Colonoscopy were compared with the findings of preoperative Colonoscopy, preoperative barium enema examination, intraoperative colon palpation, histopathologic outcome, and postoperative Colonoscopy and barium enema examination, where possible. RESULTS: Virtual Colonoscopy helped identify all 29 occlusive carcinomas and demonstrated two cancers and 24 polyps in the proximal colon. Both synchronous cancers were confirmed intraoperatively and resected. Postoperative conventional Colonoscopy in 12 patients confirmed 16 polyps identified at Virtual Colonoscopy and demonstrated two subcen...
Perry J Pickhardt - One of the best experts on this subject based on the ideXlab platform.
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ct colonography principles and practice of Virtual Colonoscopy
2009Co-Authors: Perry J PickhardtAbstract:In "CT Colonography", Perry Pickhardt and David Kim present techniques for quicker evaluation and diagnosis of colon cancer through the pioneering, specialty-changing imaging technique of Virtual Colonoscopy (VC). This combination of sophisticated X-rays and CT scans of the abdomen offers patients an alternative to Colonoscopy that is cost effective and reduces the need for unnecessary polyp removal. Abundantly illustrated in full color, this pioneering book describes CT colonography from pathogenesis, staging and treatment through indications, technique, and interpretation for the most common pathologies. You'll have the full spectrum of VC technique and be able to see procedures performed through video clips on the included DVD.
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computed tomographic Virtual Colonoscopy computer aided polyp detection in a screening population
Gastroenterology, 2005Co-Authors: Ronald M Summers, Ingmar Bitter, Richard J Choi, Perry J Pickhardt, Jianhua Yao, Marek Franaszek, Daniel Brickman, Vamsi KrishnaAbstract:Background & Aims: The sensitivity of computed tomographic (CT) Virtual Colonoscopy (CT colonography) for detecting polyps varies widely in recently reported large clinical trials. Our objective was to determine whether a computer program is as sensitive as optical Colonoscopy for the detection of adenomatous colonic polyps on CT Virtual Colonoscopy. Methods: The data set was a cohort of 1186 screening patients at 3 medical centers. All patients underwent same-day Virtual and optical Colonoscopy. Our enhanced gold standard combined segmental unblinded optical Colonoscopy and retrospective identification of precise polyp locations. The data were randomized into separate training (n = 394) and test (n = 792) sets for analysis by a computer-aided polyp detection (CAD) program. Results: For the test set, per-polyp and per-patient sensitivities for CAD were both 89.3% (25/28; 95% confidence interval, 71.8%–97.7%) for detecting retrospectively identifiable adenomatous polyps at least 1 cm in size. The false-positive rate was 2.1 (95% confidence interval, 2.0–2.2) false polyps per patient. Both carcinomas were detected by CAD at a false-positive rate of 0.7 per patient; only 1 of 2 was detected by optical Colonoscopy before segmental unblinding. At both 8-mm and 10-mm adenoma size thresholds, the per-patient sensitivities of CAD were not significantly different from those of optical Colonoscopy before segmental unblinding. Conclusions: The per-patient sensitivity of CT Virtual Colonoscopy CAD in an asymptomatic screening population is comparable to that of optical Colonoscopy for adenomas ≥8 mm and is generalizable to new CT Virtual Colonoscopy data.
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flat colorectal lesions in asymptomatic adults implications for screening with ct Virtual Colonoscopy
American Journal of Roentgenology, 2004Co-Authors: Perry J Pickhardt, Richard J Choi, Pamela A Nugent, William R SchindlerAbstract:OBJECTIVE. The clinical significance of flat lesions in colorectal cancer screening remains uncertain. The purpose of this study was to investigate the frequency, histology, and Virtual Colonoscopy detection of flat lesions in an asymptomatic screening population.SUBJECTS AND METHODS. The morphology of all detected polyps was prospectively recorded as flat or polypoid (sessile or pedunculated) in 1,233 consecutive asymptomatic adults who underwent same-day Virtual Colonoscopy and optical Colonoscopy. A flat morphology was defined as a shallow plaquelike broad-based lesion with a height of less than one half of its width.RESULTS. Of 344 polyps of 6 mm or greater confirmed at optical Colonoscopy, 17 (4.9%) were labeled as flat at both Virtual Colonoscopy and optical Colonoscopy; 17 (4.9%), at optical Colonoscopy only; and 25 (7.3%), at Virtual Colonoscopy only, yielding 59 total lesions in 52 (4.2%) of 1,233 patients. Twenty-nine (49.2%) of 59 flat lesions were adenomatous, of which four measured 10 mm or g...
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computed tomographic Virtual Colonoscopy to screen for colorectal neoplasia in asymptomatic adults
The New England Journal of Medicine, 2003Co-Authors: Perry J Pickhardt, Richard J Choi, Inku Hwang, James Butler, Michael L Puckett, Hans A Hildebrandt, Roy K H Wong, Pamela A Nugent, Pauline A Mysliwiec, William R SchindlerAbstract:background We evaluated the performance characteristics of computed tomographic (CT) Virtual Colonoscopy for the detection of colorectal neoplasia in an average-risk screening population. methods A total of 1233 asymptomatic adults (mean age, 57.8 years) underwent same-day Virtual and optical Colonoscopy. Radiologists used the three-dimensional endoluminal display for the initial detection of polyps on CT Virtual Colonoscopy. For the initial examination of each colonic segment, the colonoscopists were unaware of the findings on Virtual Colonoscopy, which were revealed to them before any subsequent reexamination. The sensitivity and specificity of Virtual Colonoscopy and the sensitivity of optical Colonoscopy were calculated with the use of the findings of the final, unblinded optical Colonoscopy as the reference standard. results The sensitivity of Virtual Colonoscopy for adenomatous polyps was 93.8 percent for polyps at least 10 mm in diameter, 93.9 percent for polyps at least 8 mm in diameter, and 88.7 percent for polyps at least 6 mm in diameter. The sensitivity of optical Colonoscopy for adenomatous polyps was 87.5 percent, 91.5 percent, and 92.3 percent for the three sizes of polyps, respectively. The specificity of Virtual Colonoscopy for adenomatous polyps was 96.0 percent for polyps at least 10 mm in diameter, 92.2 percent for polyps at least 8 mm in diameter, and 79.6 percent for polyps at least 6 mm in diameter. Two polyps were malignant; both were detected on Virtual Colonoscopy, and one of them was missed on optical Colonoscopy before the results on Virtual Colonoscopy were revealed. conclusions CT Virtual Colonoscopy with the use of a three-dimensional approach is an accurate screening method for the detection of colorectal neoplasia in asymptomatic averagerisk adults and compares favorably with optical Colonoscopy in terms of the detection of clinically relevant lesions.
