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Pfeifer GK, Corleta O, Gus P. [Evaluation of computed tomographic colonography for detection of colorectal polyps]. ARQUIVOS DE GASTROENTEROLOGIA 2009; 45:301-7. [PMID: 19148358 DOI: 10.1590/s0004-28032008000400008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 03/31/2008] [Indexed: 11/22/2022]
Abstract
BACKGROUND Computed tomographic colonography has been proposed for detection of colorectal polyps instead of colonoscopy in colorectal cancer screening programs. AIM To evaluate the performance of computed tomographic colonography in the detection of colorectal polyps with colonoscopy used as the gold standard. METHODS We prospectively studied 20 patients at high risk for colorectal neoplasia (14 men and 6 women; mean age, 55 years and 59 years). Computed tomographic colonography was performed immediately before colonoscopy. We inserted a rectal balloon catheter and insufflated the colon with room air to the level that a good distension was observed. Twenty milligrams of hioscin was given immediately before computed tomographic imaging of the abdomen and pelvis in order to minimize the degree of smooth-muscle spasm and peristalsis and to reduce the patient's discomfort. RESULTS Computed tomographic colonography images were considered satisfactory in all cases. Colonoscopy detected 85 polyps in 19 of 20 patients (95%). All the observed polyps were successfully removed and examined histologically. The radiological examination correctly identified 8 of 10 polyps 10 mm or more in diameter, 2 of 19 (18,2%) with 5-9 mm, and just 1 of 53 <5mm (9,1%). Seventeen of the 43 adenomatous polyps were > or =5 mm. Eight (47%) were correctly identified on computed tomographic colonography. None of the neoplasias <5 mm were identified on colonography. Nineteen patients preferred colonoscopy in the event of having to repeat on of the two examinations. CONCLUSION For the detection of colorectal polyps, computed tomographic colonography seems to be useful only when the result is positive, as the negative results of this examination cannot eliminate the presence of these lesions.
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Affiliation(s)
- Gustavo Kuhn Pfeifer
- Departamento de Ciências Morfológicas da Universidade Federal do Rio Grande do Sul, Porto Alegre, RS.
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Wong TYY, Lam WWM, So NMC, Lee JFY, Leung KL. Air-inflated magnetic resonance colonography in patients with incomplete conventional colonoscopy: Comparison with intraoperative findings, pathology specimens, and follow-up conventional colonoscopy. Am J Gastroenterol 2007; 102:56-63. [PMID: 17100979 DOI: 10.1111/j.1572-0241.2006.00891.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND To assess the usefulness of air-inflated magnetic resonance colonography (MRC) in patients with incomplete conventional colonoscopy (CC). METHODS From September 2001 to December 2004, 51 patients (25 male and 26 female, age range 32 to 85 years) with incomplete colonoscopy were recruited to have MRC performed. Half-fourier single short turbo spin echo (HASTE) axial, coronal, and three dimensional fat suppressed gradient echo sequence (VIBE) coronal images in both the prone and supine positions were performed for each patient. MRC was reviewed by two radiologists for detection of synchronous colonic lesion. The location and size of lesions were recorded and were compared with the findings of CC. Patients were managed according to the clinical situation and intraoperative findings were compared with MRC findings. Follow-up colonoscopy was performed in 29 patients. The follow-up colonoscopy findings were then compared with the MRC findings. RESULTS Forty-four patients had incomplete colonoscopy because of an obstructing tumor. The other seven patients had incomplete colonoscopy because of excessive bowel looping. Apart from one patient suffering from chronic obstructive airway disease with resulting nondiagnostic MRC, all other patients had MRC successfully performed. Each colon was divided into six bowel segments for analysis. All 300 segments were of diagnostic quality and were assessed by the MRC. MRC correctly identified all 44 obstructing tumors demonstrated by initial CC. Synchronous tumors in proximal colonic segments were identified in two patients by MRC. In addition, MRC identified two colonic tumors located in bowel segments inaccessible by CC because of excessive looping. CONCLUSIONS MRC is useful for detection of colonic pathology and assessment of proximal colon in patients with colonic cancer after incomplete colonoscopy.
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Affiliation(s)
- Tammy Yuen-yee Wong
- Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin, NT, Hong Kong
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Slater A, Taylor SA, Burling D, Gartner L, Scarth J, Halligan S. Colonic polyps: effect of attenuation of tagged fluid and viewing window on conspicuity and measurement--in vitro experiment with porcine colonic specimen. Radiology 2006; 240:101-9. [PMID: 16793973 DOI: 10.1148/radiol.2401050984] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
PURPOSE To investigate effect of attenuation of tagged fluid and viewing window on polyp conspicuity and measurement with porcine colonic specimen. MATERIALS AND METHODS Eleven (3-10-mm-diameter) polyps were created in porcine colon and the specimen submerged in saline. Four-detector row CT was performed after gas distension and after filling with six barium sulfate suspensions (attenuation, 100-1000 HU). Two readers independently measured maximal two-dimensional polyp diameter on each data set with the following four viewing windows and window levels and window widths, respectively: colon (-150 HU, 1500 HU), lung (-500 HU, 1500 HU), bone (500 HU, 2500 HU), and abdomen (40 HU, 400 HU). In consensus, polyp conspicuity (compared with air data set) was assigned a grade of 1-4 for each viewing window (grade 1, not seen or barely visible; grade 4, optimally seen). For statistical analysis, conspicuity grades were collapsed to a two-point scale. Data were analyzed with Mann-Whitney, Kruskal-Wallis, and chi2 tests. RESULTS Accuracy of polyp measurement was independent of viewing window for attenuation of tagged fluid of 100-300 HU but differed significantly for 500-1000 HU (P < .001); that for colonic and bone viewing windows was superior (median size difference, 1.0 mm; interquartile range, 0.5-1.5). Conspicuity differed significantly according to viewing window at all attenuation values (P < .001). For 100-300 HU with abdominal viewing window, 83% (24 of 29) of observations were assigned grade 3 or 4 (best). For 500-1000 HU with bone viewing window, 94% (30 of 32) of observations were assigned grade 3 or 4 (superior). Overall conspicuity was best with bone viewing windows at 700 HU. CONCLUSION Polyp conspicuity and measurement in tagged data sets were optimized at 700 HU with bone viewing windows. At less than 300 HU, conspicuity improved with abdominal viewing windows.
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Affiliation(s)
- Andrew Slater
- Department of Intestinal Imaging, St. Mark's Hospital, London, England
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Pilleul F, Bansac-Lamblin A, Monneuse O, Dumortier J, Milot L, Valette PJ. Water enema computed tomography: diagnostic tool in suspicion of colorectal tumor. ACTA ACUST UNITED AC 2006; 30:231-4. [PMID: 16565655 DOI: 10.1016/s0399-8320(06)73158-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The aim of this study was to assess the accuracy of water enema multi-row computed tomography for detecting clinically suspected colorectal tumor. PATIENTS AND METHODS A water enema multi-row computed tomography (WE-MR-CT) was performed in 128 consecutive patients (71 women, mean age 67.7 years) referred for suspicion of colorectal cancer. We defined at least one centimeter size of the lesion as the threshold of detection. The results of WE-MR-CT were compared with the diagnosis obtained by colonoscopy, pathology or clinical follow-up. RESULTS The overall sensitivity and specificity of water enema multi-row CT in identifying patients with colorectal lesions were 95.5% and 93.5%, respectively. The negative predictive value was 98.8% for a 10-mm threshold lesion size. WE-MR-CT allowed identifying synchronous lesions in three cases. CONCLUSIONS WE-MR-CT can accurately detect supracentimetric colorectal tumors. The performance of this technique should be further evaluated in prospective studies.
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Affiliation(s)
- Frank Pilleul
- Service de Radiologie Digestive, Hôpital Edouard Herriot, Lyon.
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Zalis ME, Perumpillichira J, Hahn PF. Digital subtraction bowel cleansing for CT colonography using morphological and linear filtration methods. IEEE TRANSACTIONS ON MEDICAL IMAGING 2004; 23:1335-1343. [PMID: 15554122 DOI: 10.1109/tmi.2004.826050] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We describe a method to perform postacquisition processing of computed tomography colonography (virtual colonoscopy) datasets that results in electronic removal of opacified, ingested bowel contents while reconstructing natural appearing boundaries of colon lumen and thereby permitting three-dimensional visual analyses of the resulting colon models.
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Affiliation(s)
- Michael E Zalis
- Department of Radiology, Massachusetts General Hospital, 55 Fruit St. Boston, MA 02114, USA.
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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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Lam WWM, Leung WK, Wu JKL, So NMC, Sung JJY. Screening of colonic tumors by air-inflated magnetic resonance (MR) colonography. J Magn Reson Imaging 2004; 19:447-52. [PMID: 15065168 DOI: 10.1002/jmri.20028] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
PURPOSE To assess the accuracy of air-inflated magnetic resonance (MR) colonography for the detection of colonic lesions. MATERIALS AND METHODS A total of 36 patients underwent both colonoscopy and air-inflated MR colonography. Breath-hold sequences (volumetric interpolated breath-hold examination (VIBE) coronal, and half-Fourier acquisition single-shot turbo spin-echo (HASTE) axial and coronal, both supine and prone) were performed with a 1.5T scanner. The detection of colonic lesions by MR colonography was then correlated with the findings from the colonoscopy performed on the same day. RESULTS Two patients were unable to complete the MR colonography examination. Analysis was based on the results from 34 patients (17 males and 17 females, 38-70 years old, mean age = 54.9 years) who completed both examinations. MR colonography depicted two of two colonic tumors, one of one P4 (> 2 cm) polyp, one of two P2 (0.5-1 cm) polyps, and two of 11 P1 (< 0.5 cm) polyps. False-positive MR colonography interpretations were noted for one P1 polyp and two P2 polyps. The overall sensitivity, positive predictive value, and accuracy of MR colonography were 38%, 67%, and 46.2%, respectively. For the detection of endoluminal lesions > 5 mm, air-inflated MR colonography yielded a sensitivity of 75%, specificity of 93.3%, accuracy of 91.2%, positive predictive value of 60%, and negative predictive value of 96.6%. CONCLUSION Air-inflated MR colonography is a new technique that deserves further investigation.
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Affiliation(s)
- Wynnie W M Lam
- Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
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Abstract
Computerized tomographic colonography (CT colonography) is a new, non-invasive technique that has been developed over the last few years; it looks at the large bowel in detail. In this chapter we look at how the examination is performed and we consider how the images are displayed. We describe the normal features of the colon, as seen using this technique, as well as the features of common pathological conditions. We will discuss screening for colorectal cancer and the performance of CT colonography; we compare the latter with other procedures currently employed in the screening and diagnosis of colorectal pathology. We consider the difficulties in interpreting these CT colonographic images and look at ways to overcome such difficulties. Finally we discuss future developments of this exciting, new technique.
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Affiliation(s)
- Clare S Smith
- Department of Radiology, Mater Misercordiae Hospital, Eccles Street, Dublin 7, Ireland
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Affiliation(s)
- H M Fenlon
- Department of Radiology, Mater Misericordiae Hospital, Eccles Street, Dublin 7, Ireland.
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Wong WD. What's new in colon and rectal surgery. J Am Coll Surg 2001; 193:633-40. [PMID: 11768680 DOI: 10.1016/s1072-7515(01)01104-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- W D Wong
- Colorectal Service, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
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Abstract
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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Affiliation(s)
- J T Ferrucci
- Department of Radiology, Boston Medical Center, Boston University School of Medicine, 88 E. Newton St., Boston, MA 02118, USA
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12
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Abstract
CT colonography (virtual colonoscopy) is a safe, noninvasive method of examining the large bowel. Since its first description in 1994, the technique has undergone rapid development, stimulating considerable interest in its potential as both a diagnostic and screening tool. Diagnostic performance statistics have been encouraging, with predictive values rivaling those of barium enema and approaching those of endoscopic colonoscopy. Improvements are underway in methods of bowel preparation, scanning procedure, and image display. Increasing experience with the technique is reflected in better understanding and characterization of both two-dimensional and three-dimensional findings, resulting in improved study performance and interpretation. This review attempts to chart the development of CT colonography, with an emphasis on published results and current research interests. We propose potential directions for future study and means toward effective implementation of CT colonography in clinical practice.
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Affiliation(s)
- J F Bruzzi
- Department of Radiology, Mater Misericordiae Hospital, Eccles Street, Dublin 7, Ireland.
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Macari M, Lavelle M, Pedrosa I, Milano A, Dicker M, Megibow AJ, Xue X. Effect of different bowel preparations on residual fluid at CT colonography. Radiology 2001; 218:274-7. [PMID: 11152814 DOI: 10.1148/radiology.218.1.r01ja31274] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The effect of different bowel preparations on residual fluid during computed tomographic (CT) colonography was evaluated. Forty-two patients received either a polyethylene glycol electrolyte solution preparation or a phospho-soda preparation the day prior to CT colonography. The amount of residual fluid was calculated for each patient. On average, a phospho-soda preparation provided significantly less residual fluid than a polyethylene glycol electrolyte solution preparation.
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Affiliation(s)
- M Macari
- Department of Radiology, Division of Abdominal Imaging, New York University Medical Center, Tisch Hospital, New York, NY 10016, USA.
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Macari M, Megibow AJ. Pitfalls of using three-dimensional CT colonography with two-dimensional imaging correlation. AJR Am J Roentgenol 2001; 176:137-43. [PMID: 11133553 DOI: 10.2214/ajr.176.1.1760137] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- M Macari
- Department of Radiology, Abdominal Imaging, NYU Medical Center, Tisch Hospital, 560 First Ave., Ste. HW 206, New York, NY 10016, USA
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Ott DJ. Accuracy of double-contrast barium enema in diagnosing colorectal polyps and cancer. Semin Roentgenol 2000; 35:333-41. [PMID: 11060920 DOI: 10.1053/sroe.2000.17754] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
CRC is a common malignancy, and reduced mortality can be achieved through detection and treatment of early cancers and by removal of colonic adenomas. Although current screening recommendations, especially in the average-risk individual, typically promote the use of FOBT and FS, a substantial minority of colonic cancers and many colonic adenomas are not detected by these methods. Modalities that examine the entire colon, such as the barium enema and colonoscopy, can detect most clinically important colorectal neoplasms; however, their additional costs and potential risks have limited their use as initial screening examinations. But recent changes in governmental policies regarding reimbursement for CRC screening and increasing emphasis on total colon examinations have altered these recommendations. This review on the accuracy of the DCBE has emphasized the detection of colonic polyps and cancers and has updated the changing role of this examination in screening patients at variable risk for CRC. The efficacy of the barium enema depends on many factors that radiologists must understand and control to perform accurate examinations. Current recommendations for CRC screening and approved reimbursement of the barium enema for that purpose provide a new impetus to radiologists to maintain and improve their skills in performing and interpreting this radiologic examination. The barium enema may have a future in the new millennium.
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Affiliation(s)
- D J Ott
- Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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Abstract
Computed tomographic (CT) colonography is a new-generation technique for detecting colorectal neoplasms by using volumetric CT data combined with specialized imaging software. Patient examinations require full colonic preparation, insufflation, and data acquisition with the patient in the supine and prone positions. Current CT technology allows a single image of the colon to be acquired in as little as 20 seconds with a minimum of patient discomfort. Specialized computer software for interpretation usually combines transverse, multiplanar reformation, and three-dimensional endoluminal images for the optimal visualization of the colon and rectum. As of the time this article was written, CT colonography was competitive as a full structural colonic examination for the detection of polyps and cancer. To the authors' knowledge, no study results have yet been reported in a screening population. The unique capabilities of CT colonography include the display of the proximal colon that is inaccessible at colonoscopy because of obstructing colonic lesions or because of incomplete endoscopic examinations and the assessment of extracolonic abdominal and pelvic organs. This abdominopelvic survey potential provides radiologists with an opportunity to discover other potentially life-threatening, asymptomatic conditions. Further technologic developments and validation studies are in progress. CT colonography is an exciting and promising technique with an enormous potential for colorectal screening in the future.
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Affiliation(s)
- C D Johnson
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
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Ferrucci JT. CT colonography for colorectal cancer screening: lessons from mammography. AJR Am J Roentgenol 2000; 174:1539-41. [PMID: 10845477 DOI: 10.2214/ajr.174.6.1741539] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- J T Ferrucci
- Department of Radiology, Boston University School of Medicine, Boston Medical Center, MA 02118, USA
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