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Igarashi T, Zenbutsu S, Yamanishi T, Naya Y. Three-dimensional image processing system for the ureter and urethra using endoscopic video. J Endourol 2008; 22:1569-72. [PMID: 18657032 DOI: 10.1089/end.2008.0150] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
We developed new software that enables three-dimensional (3D) images of the ureter and urethra to be automatically processed from the video image of a conventional endoscope. The entire image of the ureter or urethra is displayed opened in a picture like a 3D map. The locations of lesions and the 3D structure of the prostatic urethra are depicted using this method, which enables quantitative evaluation of lesions and the obstructive potential of the prostatic urethra. Application of the technology in the urinary tract is discussed.
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Affiliation(s)
- Tatsuo Igarashi
- Research Center for Frontier Medical Engineering, Chiba University, Chiba City, Chiba, Japan.
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Xiong T, McEvoy K, Morton DG, Halligan S, Lilford RJ. Resources and costs associated with incidental extracolonic findings from CT colonogaphy: a study in a symptomatic population. Br J Radiol 2006; 79:948-61. [PMID: 16822798 DOI: 10.1259/bjr/58438178] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
CT colonography (CTC) is increasingly used to detect colonic polyps and cancers, but its impact in practice is also influenced by frequent detection of extracolonic lesions. We have previously documented the frequency and nature of such lesions. The current study was performed to assess the clinical resources and costs associated with the investigation and treatment of extracolonic lesions. We reviewed the reports of 225 consecutive CTC examinations carried out on patients with symptoms of bowel cancer. 116 of the 225 were reported to have one or more extracolonic findings. All 116 patients with an abnormality were followed up for 12-24 months. 24 patients underwent further actions (outpatient attendance, investigations, or surgical procedures) as a result of previously undiagnosed lesions unrelated to bowel cancer. The costs of these further actions were derived from the NHS Reference Costs manual 2004. The total cost for further investigations and interventions was 34,329 pounds sterling and the mean cost over the sample of 225 patients was 153 pounds sterling--more than the cost of the CTC itself. The costs were mainly generated by surgical procedures. Resources consumed as a result of extracolonic findings approximately doubled the costs of diagnostic CTC. These costs, along with inconvenience, anxiety, morbidity and occasionally even mortality suffered by patients, must be offset by the good done to some of those with sub-clinical but potentially lethal diseases.
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Affiliation(s)
- T Xiong
- Department of Public Health and Epidemiology, Public Health Building, The University of Birmingham, Edgbaston, Birmingham B15 2TT.
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Rajapaksa RC, Macari M, Bini EJ. Prevalence and impact of extracolonic findings in patients undergoing CT colonography. J Clin Gastroenterol 2004; 38:767-71. [PMID: 15365402 DOI: 10.1097/01.mcg.0000139035.38568.18] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND CT colonography (virtual colonoscopy) is a new technique being offered to patients as a noninvasive method of imaging the colon. The aims of this study were to prospectively determine the prevalence of extracolonic findings in patients undergoing CT colonography, as well as to determine the clinical significance and consequences of these findings. METHODS Two-hundred and fifty patients who were referred for colonoscopy for clinically indicated reasons underwent CT colonography using low-dose radiation (50 mAs) immediately prior to conventional colonoscopy. A single radiologist reviewed the CT images for extracolonic pathology, and findings were classified as having high, moderate, or low clinical significance. Electronic medical records were reviewed to assess what follow up diagnostic tests, if any, were performed. RESULTS A total of 136 extracolonic findings were detected in 83 (33.2%) of the 250 patients. Of these 136 findings, 17 (12.5%) were highly significant, 53 (38.9%) were moderately significant, and 66 (48.5%) were of low significance. The most common highly significant lesions were solitary lung nodules in 3 patients, mesenteric lymphadenopathy in 3, adrenal masses in 2, low attenuation liver lesions consistent with metastases in 2, and bone metastases in 2 patients. Fourteen of the 17 (82.4%) highly significant findings were new findings, and in 11 the extracolonic abnormalities resulted in further diagnostic testing. None of the patients with moderate or low significance lesions underwent further testing. CONCLUSIONS Low-dose CT colonography can detect highly significant extracolonic findings. Although extracolonic lesions were common, only a small proportion of patients required further diagnostic testing. Additional studies to determine the optimal radiation dose, cost-effectiveness, and legal implications of detecting extracolonic findings are warranted.
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Affiliation(s)
- Roshini C Rajapaksa
- VA New York Harbor Healthcare System, New York University Medical Center/Tisch Hospital, and New York University School of Medicine, New York 10010, USA
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Koch M, Kienle P, Sauer P, Willeke F, Buhl K, Benner A, Lehnert T, Herfarth C, von Knebel Doeberitz M, Weitz J. Hematogenous tumor cell dissemination during colonoscopy for colorectal cancer. Surg Endosc 2004; 18:587-91. [PMID: 14735340 DOI: 10.1007/s00464-003-9066-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2003] [Accepted: 07/22/2003] [Indexed: 02/07/2023]
Abstract
BACKGROUND It has long been suspected that mechanical influences may enhance the release of viable colorectal cancer cells into the circulation. The objective of this study was to determine the extent of hematogenous tumor cell spread in colorectal cancer patients during colonoscopy. METHODS Peripheral venous blood samples were taken before and after colonoscopy from 44 patients with colorectal cancer. Blood samples were examined using a reverse-transcriptase polymerase chain reaction assay to amplify cytokeratin 20 transcripts. RESULTS Eleven patients with colorectal cancer displayed circulating tumor cells before and after colonoscopy (25%), whereas tumor cells were detected in six of 44 patients (14%) only after the procedure (p = 0.03, McNemar's test: tumor cell detection before after colonoscopy). All control samples consistently tested negative. CONCLUSIONS Mechanical forces may result in enhanced release of viable colorectal cancer cells into the circulation; however, the clinical significance of these results needs to be clarified.
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Affiliation(s)
- M Koch
- Division for Molecular Diagnostics and Therapy, Department of Surgery, University of Heidelberg, INF 110, D-69120 Heidelberg, Germany
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Biancone L, Fiori R, Tosti C, Marinetti A, Catarinacci M, De Nigris F, Simonetti G, Pallone F. Virtual colonoscopy compared with conventional colonoscopy for stricturing postoperative recurrence in Crohn's disease. Inflamm Bowel Dis 2003; 9:343-50. [PMID: 14671482 DOI: 10.1097/00054725-200311000-00001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The place of virtual colonoscopy (VC) in patients with Crohn's disease (CD) requiring endoscopic follow-up after surgery is unknown. The authors compared findings from VC versus conventional colonoscopy (CC) for assessing the postoperative recurrence of CD. METHODS Sixteen patients with ileocolonic anastomosis for CD were prospectively enrolled from January 2001 to January 2002. Recurrence was assessed by CC according to Rutgeerts et al. VC was performed with a computed tomography scanner, with images examined by three radiologists who were unaware of the endoscopic findings. RESULTS CC showed perianastomotic recurrence in 15 of 16 patients. Perianastomotic narrowing or stenosis was detected by VC in 11 of these 15 patients. There were 11 true positive, 1 true negative, 0 false-positive, and 4 false-negative findings (73% sensitivity, 100% specificity, 100% positive predictive value, 20% negative predictive value, 75% accuracy). Among the eight patients showing a rigid stenosis of the anastomosis not allowing passage of the colonoscope, VC detected narrowing or stenosis in seven patients. CONCLUSIONS The current findings suggest that although the widespread use of VC in CD is currently not indicated because of possible false-negative findings, this technique may represent an alternative to CC in noncompliant postsurgical patients with a rigid stenosis not allowing passage of the endoscope.
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Affiliation(s)
- Livia Biancone
- Cattedra di Gastroenterologia, Dipartimento di Medicina Interna, Center of Excellence for the Study of the Genomic Risk of Complex Multifactoral Diseases, Università di Roma, Rome, Italy.
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Ristvedt SL, McFarland EG, Weinstock LB, Thyssen EP. Patient preferences for CT colonography, conventional colonoscopy, and bowel preparation. Am J Gastroenterol 2003; 98:578-85. [PMID: 12650790 DOI: 10.1111/j.1572-0241.2003.07302.x] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The aim of this study was to determine patient pre-examination expectations and postexamination appraisals for CT colonography, conventional colonoscopy and bowel preparation. METHODS Prospective evaluation of 120 patients at defined risk for colorectal neoplasia was performed with CT colonography followed by colonoscopy on the same day. Subjects were stratified by age and sex (67 women and 53 men) and were randomized to receive either manual air (n = 61) or CO(2) (n = 59) insufflation during CT colonography. Patients' expectations were assessed just before the two examinations, and appraisals were assessed 2 to 3 days afterward regarding pain/discomfort, embarrassment, difficulty, overall assessment, preference for future testing, and bowel preparation. RESULTS No significant differences were found in appraisals of manual air versus CO(2) insufflation techniques. For both CT colonography and colonoscopy, patients' appraisals after the procedure were significantly more positive than prior expectations. Patients expressed more favorable appraisals of colonoscopy for pain (p < 0.001) and embarrassment (p < 0.001), with most responses being "none" to "a little" for both examinations. Overall appraisals of the tests were favorable and similar between CT and colonoscopy: patients mainly expressed "not unpleasant" to "a little unpleasant" (95%, 114/120 for both examinations). Overall, appraisal of the bowel preparation was the most negative. Preferences for future testing were more favorable toward CT: of the patients, 58% (69/120) preferred CT, 14% (17/120) preferred colonoscopy, and 28% (34/120) had no preference. CONCLUSIONS Overall appraisals were similar and positive for both CT colonography and colonoscopy, with less favorable appraisals of the bowel preparation. Most patients stated that they would prefer CT for future evaluation.
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Affiliation(s)
- Stephen L Ristvedt
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110-1093, USA
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Martin DR, Yang M, Thomasson D, Acheson C. MR colonography: development of optimized method with ex vivo and in vivo systems. Radiology 2002; 225:597-602. [PMID: 12409600 DOI: 10.1148/radiol.2251011664] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
An ex vivo magnetic resonance (MR) colonographic system with a bovine colon with polyps of predetermined dimensions was developed for evaluation and optimization of different combinations of imaging sequences and intraluminal contrast agents. Findings were then applied during in vivo testing in human subjects. The results show that optimized contrast and lesion conspicuity and minimized motion artifacts can be obtained with true fast imaging with steady-state precession combined with water as an intraluminal contrast agent.
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Affiliation(s)
- Diego R Martin
- Department of Abdominal Imaging, West Virginia University School of Medicine, Robert C. Byrd Health Sciences Center, PO Box 9235, Morgantown, WV 26505-9235, USA.
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McFarland EG, Pilgram TK, Brink JA, McDermott RA, Santillan CV, Brady PW, Heiken JP, Balfe DM, Weinstock LB, Thyssen EP, Littenberg B. CT colonography: multiobserver diagnostic performance. Radiology 2002; 225:380-90. [PMID: 12409570 DOI: 10.1148/radiol.2252011625] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE To prospectively evaluate multiobserver diagnostic performance and reader agreement for colorectal polyp detection in a well-characterized cohort of patients with increased number of polyps, compared with an average-risk patient, with colonoscopy as the reference standard. MATERIALS AND METHODS A cohort of 70 patients suspected of having polyps was examined with spiral computed tomographic (CT) colonography, with colonoscopy performed the same day. After air insufflation per rectum, supine and prone images were obtained with single-detector row CT (5-mm collimation, 8-mm table increment, 2-mm reconstruction interval). Images were analyzed independently by four experienced abdominal radiologists using two-dimensional multiplanar reformation followed by selective use of three-dimensional endoscopic volume-rendered images. Data were analyzed both per polyp and per patient. RESULTS Analysis per polyp demonstrated a pooled sensitivity of 0.68 for lesions 10 mm or larger (n = 40), with 75% agreement among the four readers. Analysis per patient demonstrated improved detection and agreement, with a pooled sensitivity of 0.88 for patients with polyps or cancers 10 mm or larger (n = 28), with 94% agreement. When sensitivity and receiver operating characteristic analyses were analyzed per polyp size threshold, results among readers converged and peaked at polyp diameters of approximately 10 mm. CONCLUSION In this patient cohort, diagnostic performance and interobserver agreement with single-detector row CT colonography was sufficient for detection of patients with lesions 10 mm or larger, with more variable results for smaller polyps.
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Affiliation(s)
- Elizabeth G McFarland
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S Kingshighway Blvd, St Louis, MO 63110, USA.
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Power NP, Pryor MD, Martin A, Horrocks J, McLean AM, Reznek RH. Optimization of scanning parameters for CT colonography. Br J Radiol 2002; 75:401-8. [PMID: 12036832 DOI: 10.1259/bjr.75.893.750401] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
To determine the optimal collimation, pitch and reconstruction interval for CT colonography, 10 spherical polyps between 1 mm and 10 mm diameter and made of tissue equivalent material with a CT number of 40 Hounsfield units (HU) were placed in the colon of an anthropomorphic phantom. The phantom was scanned at slice thicknesses of 3 mm, 5 mm and 7 mm and pitches of 1.0, 1.3, 1.5, 1.7 and 2.0 on an IGE Hispeed advantage system. Images were reconstructed for each scanning parameter at the minimum intervals allowed along the z-axis. The optimum scanning protocol was assessed by measuring maximum contrast between the polyp and air, sensitivity for detection of each polyp along the z-axis, and relative radiation dose. In addition, images were reviewed separately by two radiologists who graded polyp conspicuity as: 0, not seen; 1, faintly seen; 2, well seen. It was found that varying the scanning parameters caused a marked alteration in the maximum contrast between each polyp and air. For example, for the 5 mm polyp, the range of contrasts from best to worst case was 910-490 HU. It was noted that with contrasts of less than 500 HU, polyps were only faintly seen. A slice thickness of 3 mm with a pitch of 2 offers optimal polyp conspicuity with a relatively low radiation dose, we conclude that scanning parameters can be optimized for threshold contrast, radiation dose and subjective conspicuity. We propose an optimal parameter of 3 mm slice thickness and pitch 2.
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Affiliation(s)
- N P Power
- Department of Radiology, St. Bartholomew's Hospital, West Smithfield, London EC1A 7EB, UK
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Naganawa S, Iwayama E, Koshikawa T, Fukatsu H, Ishigaki T, Ninomiya A, Aoki I. Virtual endoscopy of the labyrinth, using a 3D-FastASE sequence. J Magn Reson Imaging 2001; 13:792-6. [PMID: 11329203 DOI: 10.1002/jmri.1110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Virtual endoscopy (VE) of the labyrinth was performed using three-dimensional (3D)-fast asymmetric spin-echo MR imaging. The spatial resolution requirements and the usefulness of zero-fill interpolation (ZIP) were evaluated, and VE was used to examine three patients. The (0.6-mm) voxel data with ZIP satisfies the minimum requirements for VE for evaluation of the complex 3D anatomy and pathology of the labyrinth. J. Magn. Reson. Imaging 2001;13:792-796.
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Affiliation(s)
- S Naganawa
- Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, Shouwa-ku, Nagoya 466-8550, Japan.
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Abstract
Virtual endoscopy is the processing of computerized tomography image data to create a virtual environment of the human body to allow diagnosis of disease processes. This new technique allows the observer the opportunity to interact with an image that is artificially generated by the computer. Virtual colonoscopy provides a method for processing data that can display computer images of the colon in a more anatomic life-like format to facilitate image interpretation and improve diagnostic accuracy. The clinical application of virtual endoscopic techniques is also being used with other procedures such as bronchoscopy, gastroscopy, cystoscopy, sinus imaging, virtual angioscopy, and cerebral ventriculography. Current screening recommendations for colorectal cancer are discussed in this article along with methods, advantages, challenges, and future opportunities for virtual colonoscopy.
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Affiliation(s)
- C M Dykes
- University of Texas Southwestern Medical Center, 5323 Harry Hines, Dallas, TX 75390-8887, USA.
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Miao YM, Amin Z, Healy J, Burn P, Murugan N, Westaby D, Allen-Mersh TG. A prospective single centre study comparing computed tomography pneumocolon against colonoscopy in the detection of colorectal neoplasms. Gut 2000; 47:832-7. [PMID: 11076883 PMCID: PMC1728155 DOI: 10.1136/gut.47.6.832] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND AND AIMS To determine the sensitivity and specificity of computed tomography (CT) pneumocolon in the detection of colorectal neoplasms. METHODS A total of 201 consecutive patients with colorectal symptoms or requiring surveillance for colorectal neoplasms underwent both conventional colonoscopy and CT pneumocolon. RESULTS On conventional colonoscopy 13 invasive colorectal carcinomas were detected in 13 patients, and 118 polyps in 63 patients (14 polyps were > or =1 cm in diameter, 25 were 6-9 mm, and 79 were < or =5 mm). CT pneumocolon detected all 13 cancers, two false positive cancers, but only 20 polyps (seven were > or =1 cm). This resulted in a sensitivity of 100% (95% confidence interval (CI) 87-100%) and specificity of 99% (95% CI 97-100%) for detection of invasive carcinoma, and a sensitivity of 73% (95% CI 56-90%) and specificity of 94% (95% CI 91-98%) for detection of invasive carcinoma and/or > or =1 cm polyps. CT pneumocolon also identified invasive carcinoma not seen at colonoscopy because of incomplete examination in three patients, and detected metastases in six colorectal carcinoma patients and extracolonic carcinoma in a further seven patients. CONCLUSIONS CT pneumocolon had a high sensitivity and specificity for detection of invasive colorectal carcinoma but not colorectal polyps. CT pneumocolon may be suitable for initial investigation of patients with symptoms of colorectal malignancy.
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Affiliation(s)
- Y M Miao
- Department of Gastroenterology, Chelsea and Westminster Hospital, London, UK
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Abstract
Computed tomography (CT) represents the preferred imaging modality for imaging the large bowel when virtual endoscopic reconstructions are desired. Using the spiral acquisition technique, it has become possible to scan the entire abdomen within a single breathhold, however, slice thicknesses of 5 mm or more are necessary should the breathhold not last longer than 30-40 s. With the advent of multislice CT, contiguous 1-mm slices can be obtained through the entire abdomen while even shortening the breathhold to 25-30 s. The improved speed and spatial resolution of multislice CT results in remarkably sharp virtual reconstructions allowing detection of polyps with sizes less than 3 mm. The disadvantages must still be considered including a dataset consisting of up to 800 images representing a new challenge for postprocessing hard- and software.
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Affiliation(s)
- P Rogalla
- Department of Radiology, Charité Hospital, Humboldt-Universität zu Berlin, Schumannstr. 20/21, 10098, Berlin, Germany.
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