Search

Although multimodality imaging plays an essential role in the staging of esophageal neoplasia, it is less helpful for the evaluation of common esophageal symptoms, such as dysphagia, regurgitation, and heartburn, than the barium esophagram. Therefore this chapter begins by describing the essential techniques, normal findings, and common artifacts of the esophagram. Subsequently, the utility of the esophagram is discussed in the settings of gastroesophageal reflux disease, esophageal motility disorders, postoperative esophagus, and esophageal neoplasms (a discussion of the role of cross-sectional imaging, especially positron emission tomography, for esophageal tumor staging is included in this section). Finally, miscellaneous conditions such as hiatal hernias, esophageal rings and webs, less common types of esophageal strictures, caustic injury, and esophageal perforation, diverticula, and varices are discussed and illustrated.

The "effervescent gallbladder" sign, the sonographic finding of tiny echogenic foci rising from the dependent portion of the gallbladder, reminiscent of bubbles rising in a glass of champagne, has been reported previously as a finding of emphysematous cholecystitis. We report two additional cases of this unusual finding in an asymptomatic patient and in a patient with acute, gangrenous cholecystitis, confirmed in both cases by CT, to be secondary to the release of gas from gallstones. These two cases cast doubt on the sonographic sign as a pathognomonic finding of emphysematous cholecystitis.

The purpose of our study was to evaluate the performance of noncathartic, dietary unrestricted CT colonography, without and with the aid of electronic stool subtraction, for detecting colorectal neoplasia in a high-prevalence referral population.Patients with known or suspected colorectal neoplasms were potentially eligible for participation, regardless of the presence or absence of gastrointestinal symptoms. Subjects ingested 21.6 g of barium in nine divided doses. CT colonography was performed in the standard fashion. Data sets were randomly evaluated by two of three experienced radiologists, with subsequent reanalysis of each data set after electronic stool subtraction at least 6 weeks later. Optical colonoscopy was performed after purgation and served as the reference standard.One hundred thirty-one adenomatous neoplasms were identified among 114 subjects. On a per subject basis, the sensitivity for detecting adenomas 6-9 oror = 10 mm in diameter ranged from 53% to 88% and 84% to 93% without stool subtraction, respectively. By including stool subtraction, these sensitivity estimates improved to 68% to 92% and 93% to 94%, respectively. Specificity ranged from 71% to 91% and 88% to 100% for lesions 6-9 andor = 10 mm in size, respectively. Double reading resulted in detection of 27 (87%) of 31 and 65 (96%) of 68 patients with 6-9 andor = 10 mm adenomas, respectively. With double reading, the area under the receiver operating characteristic curve for large adenomas was 0.97.In this increased-risk referral population, CT colonography in the non-cathartic-tagged colon without dietary restrictions compared favorably with optical colonoscopy.

Using a 3D rendering technique called "virtual dissection," we sought to evaluate polyp and fold distortion using a colon phantom, estimate the polyp detection performance in humans, and estimate the added benefit of double interpretation and computer-aided diagnosis.A colon phantom containing 144 polyps of varying sizes (5-12 mm) and shapes (flat, sessile, pedunculated) was scanned. Polyp shape and distortion at virtual dissection were categorized as flame, club, pea, or bizarre. Haustral fold distortion was graded. The CT colonography examinations in 20 consecutive patients (colonoscopically proven normal findings, n = 5; polypsor = 1 cm, n = 17 in 15 patients) were blindly reviewed by three radiologists using the virtual dissection technique. The added benefits of double interpretation and computer-aided diagnosis were tabulated.Sessile polyps appeared flame (35/48 [73%]) or pea (11/48 [23%]) in shape. Flat polyps appeared flame-shaped (31/47 [66%]) or pea-shaped (16/47 [34%]). Pedunculated polyps were flame (15/45 [33%]), club (20/45 [44%]), or pea (6/45 [13%]) in shape. Axial distortion occurred along the longitudinal axis. The sensitivities of the three observers for polyps of 1 cm or more were 16/17 (94%), 14/17 (82%), and 15/17 (88%). The specificities were 5/5 (100%), 5/5 (100%), and 4/5 (80%). Sensitivities after double interpretation and computer-aided diagnosis improved but did not reach statistical significance.Although distortion of colonic structures exists at virtual dissection, it does so in recognizable patterns, so that sensitivity for polyp detection is not compromised.

Background & Aims: No multicenter study has been reported evaluating the performance and interobserver variability of computerized tomographic colonography. The aim of this study was to assess the accuracy of computerized tomographic colonography for detecting clinically important colorectal neoplasia (polyps ≥10 mm in diameter) in a multi-institutional study. Methods: A retrospective study was developed from 341 patients who had computerized tomographic colonography and colonoscopy among 8 medical centers. Colonoscopy and pathology reports provided the standard. A random sample of 117 patients, stratified by criterion standard, was requested. Ninety-three patients were included (47% with polyps ≥10 mm; mean age, 62 years; 56% men; 84% white; 40% reported colorectal symptoms; 74% at increased risk for colorectal cancer). Eighteen radiologists blinded to the criterion standard interpreted computerized tomography colonography examinations, each using 2 of 3 different software display platforms. Results: The average area under the receiver operating characteristic curve for identifying patients with at least 1 lesion ≥10 mm was 0.80 (95% lower confidence bound, 0.74). The average sensitivity and specificity were 75% (95% lower confidence bound, 68%) and 73% (95% lower confidence bound, 66%), respectively. Per-polyp sensitivity was 75%. A trend was observed for better performance with more observer experience. There was no difference in performance across software display platforms. Conclusions: Computerized tomographic colonography performance compared favorably with reported performance of fecal occult blood testing, flexible sigmoidoscopy, and barium enema. A prospective study evaluating the performance of computerized tomography colonography in a screening population is indicated.

Background & Aims: This study used a low lesion prevalence population reflective of the screening setting to estimate the sensitivity and specificity of computerized tomographic (CT) colonography for detection of colorectal polyps. Methods: This prospective, blinded study comprised 703 asymptomatic persons at higher-than-average risk for colorectal cancer who underwent CT colonography followed by same-day colonoscopy. Two of 3 experienced readers interpreted each CT colonography examination. Results: Overall lesion prevalence for adenomas ≥1 cm in diameter was 5%. Seventy percent of all lesions were proximal to the descending colon. With colonoscopy serving as the gold standard, CT colonography detected 34%, 32%, 73%, and 63% of the 59 polyps ≥1 cm for readers 1, 2, 3, and double-reading, respectively; and 35%, 29%, 57%, and 54% of the 94 polyps 5–9 mm for readers 1, 2, 3, and double-reading, respectively. Specificity for CT colonography ranged from 95% to 98% and 86% to 95% for >1 cm and 5–9-mm polyps, respectively. Interobserver variability was high for CT colonography with κ statistic values ranging from −0.67 to 0.89. Conclusions: In a low prevalence setting, polyp detection rates at CT colonography are well below those at colonoscopy. These rates are less than previous reports based largely on high lesion prevalence cohorts. High interobserver variability warrants further investigation but may be due to the low prevalence of polyps in this cohort and the high impact on total sensitivity of each missed polyp. Specificity, based on large numbers, is high and exhibits excellent agreement among observers.

Background & Aims: To assess the prevalence and spectrum of extracolonic findings in a screening population undergoing computed tomography colonography (CTC), and to evaluate the short-term direct medical costs incurred from subsequent radiologic follow-up evaluation. Methods: Six hundred and eighty-one asymptomatic patients undergoing colonoscopy screening consented to a CTC examination. Extracolonic CT findings were classified into high, medium, and low importance. Clinical and radiologic follow-up, missed lesions, and outcomes were assessed by chart review (time interval, 410-1513 days; median, 913 days). Short-term direct medical costs of radiologic follow-up were determined based on Medicare 2002 reimbursement rates. Results: Extracolonic findings were found commonly. These were categorized as high clinical importance in 71 (10%) individuals, as medium importance in 183 individuals (27%), and as low importance in 341 individuals (50%). Subsequent medical or surgical interventions resulted from these findings in 9 of the 681 patients (1.3%). Costs of subsequent radiologic follow-up studies were calculated as $23,380.59 (average added costs per CTC examination $34.33). Conclusions: CTC commonly detects extracolonic findings that can be considered clinically important when applied to an asymptomatic screening population. Although such incidental findings add benefit to the screening intervention, moderate incremental costs are incurred based on additional radiologic procedures generated during short-term follow-up.

Background:We investigated whether flat lesions of the colon could be detected on computed tomographic colonography (CTC). Methods: CTC and conventional colonoscopy were performed on 547 consecutive patients. A subset of 22 polyps was described as flat on colonoscopy (n= 16) or CTC (n= 6) and are the basis of this report. CTC was performed with a standard technique (5-mm collimation, 3-mm reconstruction intervals). Patients were scanned in supine and prone positions. Examinations were randomly assigned and reviewed in a blinded fashion by two of three radiologists. Prospective interpretations were recorded. All patients had conventional colonoscopy, which served as the gold standard. Results: Twenty-two flat lesions ranging from 0.4 to 3.5 cm were histologically classified as adenomatous (n= 8) or hyperplastic (n= 14). The sensitivities for detecting all flat lesions and flat adenomas by each reviewer were 43% and 100%, 65% and 100%, and 15% and 13%, respectively. “Double reading” resulted in detection of 68% of all lesions and 100% of adenomas. Of the seven hyperplastic polyps missed by both reviewers, four were identified retrospectively. Conclusion: Flat lesions of the colon represent an important source of false negative CTC examinations. Awareness of their morphology can assist radiologists in finding most of these challenging lesions.

Our aim was to evaluate the safety and assess the efficacy of pirfenidone, an antifibrotic drug, in patients with primary sclerosing cholangitis (PSC). Twenty-four patients with PSC were enrolled in this pilot study. Oral pirfenidone, 2400 mg daily, was given for one year. Liver biochemistries were determined at three-month intervals. The Mayo risk score was calculated, and liver biopsy and endoscopic cholangiography were performed at entry and at one year of treatment. No significant changes in liver biochemistries were noted at the end of the treatment period or at any of the three-month intervals. The Mayo risk score did not change significantly, and no significant changes were noted in the degree of inflammation, fibrosis, histologic stage of disease, or cholangiographic findings at the end of the treatment period. Adverse events occurred in 20/24 (83%) patients, but disappeared shortly after pirfenidone was discontinued. Pirfenidone did not benefit patients with PSC, and it was frequently associated with adverse events. The results of this pilot study discourage further trials of pirfenidone in patients with PSC.

To assess the added benefits of prone positioning in addition to supine positioning and oral iodinated contrast medium for help in the detection of colonic polyps at computed tomographic (CT) colonography.CT colonography was performed in prone and supine positions in 180 patients with polyps or risk factors for colonic neoplasia. Patients were randomly assigned to receive a standard bowel preparation or a standard preparation plus oral iodinated contrast medium. One radiologist interpreted supine images alone, and another analyzed supine and prone images. All patients subsequently underwent colonoscopy.At colonoscopy, 121 large (or =1-cm-diameter) polyps and 142 smaller (0.5-0.9-cm) polyps were identified. Prone positioning resulted in increased sensitivity for identification of patients with large (or =1-cm) polyps (increase from 70% to 85%, P: =.004) and of patients with polyps 0.5 cm or larger (increase from 75% to 88%, P:.005), with no change in specificity. Use of oral contrast medium did not significantly improve polyp detection even in the subset of patients in whom colonic fluid attenuation was markedly increased.Acquisition and review of supine and prone CT colonographic images significantly improves the ability to identify patients with polyps 0.5 cm in diameter or larger. Administration of oral iodinated contrast medium does not significantly improve polyp detection.

2Department of Radiology, Mayo Clinic Rochester, Mayo East 2-B, 200 First St. SW, Rochester, MN 55905. Address correspondence to J. G. Fletcher. T colonography, or virtual colonoscopy, is now routinely used as a full structural examination of the colorectum following incomplete endoscopy [1] and in patients with elevated risk for complications during endoscopy or with aversion to endoscopy. CT colonography has demonstrated performance on par with optical colonoscopy in the screening of asymptomatic patients for adenomatous polyps in some hands [2] and has performed superiorly compared with nonendoscopic alternatives [3]. Optimal colonic inflation is essential to a high-quality CT colonography examination. Given the speed of image acquisition and reconstruction of MDCT scanners, patients must tolerate maximum inflation for only a few seconds, as opposed to endoscopy and barium enema, in which the colon remains inflated for much longer periods of time. Nevertheless, colonic insufflation is known to result in perforation, ranging from approximately 0.004–0.01% of cases for double contrast barium enema [4, 5] to 0.07–0.19% of cases for colonoscopy [6, 7]. To date, thousands of patients have undergone CT colonography without complications. Two cases of colonic perforation at CT have recently been reported in patients with known colonic disease [8, 9]. We report a case of perforation following CT colonography in a patient without known colonic disease.

The "effervescent gallbladder" sign, the sonographic finding of tiny echogenic foci rising from the dependent portion of the gallbladder, reminiscent of bubbles rising in a glass of champagne, has been reported previously as a finding of emphysematous cholecystitis. We report two additional cases of this unusual finding in an asymptomatic patient and in a patient with acute, gangrenous cholecystitis, confirmed in both cases by CT, to be secondary to the release of gas from gallstones. These two cases cast doubt on the sonographic sign as a pathognomonic finding of emphysematous cholecystitis.

We studied cholangiograms in 129 patients with primary sclerosing cholangitis (PSC) to determine if there was a correlation between any of the findings and the prognosis of the disease. The grade, length, and extent of strictures, the degree of bile duct dilatation, and the distribution of lesions were evaluated. Survival curves were generated to test the association of these radiologic signs with subsequent survival. High-grade intrahepatic duct strictures (greater than 75% narrowing) were associated with a 19% decrease in 3-year survival (p = .05) compared with lower-grade strictures. Diffuse intrahepatic strictures (involving greater than 25% of the ducts) were associated with a 16% decrease in 3-year survival (p = .012) compared with localized strictures. Statistically insignificant (p greater than .05) but measurable decreases in survival were observed with high-grade extrahepatic duct strictures, diffuse involvement of the extrahepatic ducts, long confluent strictures anywhere in the biliary tree, and marked dilatation of the intrahepatic ducts. In general, intrahepatic duct disease was found to have greater prognostic significance than extrahepatic duct disease. High-grade strictures and diffuse strictures of the intrahepatic ducts were found to be indicators of a poor prognosis in PSC and were more predictive of a poor prognosis than was extrahepatic duct disease.

Objective Two-thirds of the US population is overweight or obese. Sedentary lifestyles and occupations are one factor in the development of obesity. Methods to help reduce sedentary work environments may help reduce obesity. The purpose of this study was to determine the feasibility of using a walking workstation during computed tomographic image interpretation. Methods Two radiologists reinterpreted 100 clinical computed tomographic examinations they had previously interpreted, each while walking at 1 mph on a treadmill using an electronic workstation. Ten cases were reviewed per session. The time period between the initial conventional interpretations and the reinterpretations was greater than one year, to reduce recall bias. Discrepant findings were ranked according to a classification system based on clinical importance on a scale ranging from 1 to 6. Discrepant findings classified as greater than or equal to 3 were considered significant. Detection rates for the initial interpretations and reinterpretations were determined for each reviewer and compared using a paired t -test. Results A total of 1,582 findings were reported (825 by reviewer 1 and 757 by reviewer 2). There were 459 findings with clinical importance of 3 or higher. For reviewer 1 (91 cases of at least one important finding), the mean detection rates were 99.0% for the walking technique and 88.9% for the conventional interpretations ( P = .0003). For reviewer 2 (89 cases with at least one important finding) the mean detection rates were 99.1% for the walking technique and 81.3% for the conventional interpretations ( P Conclusion The use of a walking workstation for the interpretation of cross-sectional images is feasible. Further studies are needed to assess the potential impact on diagnostic accuracy.

The objective of our study was to compare the performance of primary 3D search using 360 degree virtual dissection with primary 2D search using a 2.5- versus a 1.25-mm slice thickness.Four hundred fifty-two asymptomatic patients underwent CT colonography (CTC) and colonoscopy. Examinations were reconstructed to 1.25- and 2.5-mm slice thicknesses and interpreted using primary 3D search (360 degree virtual dissection) and primary 2D search. Two of three experienced reviewers were randomly assigned to each case; 1,808 interpretations were performed.There were 64 adenomasor = 6 mm, 26 of which were large adenomasor = 1 cm. For adenomas 6-9 mm in diameter, the area under the receiver operating characteristic curve (AUC) using 2.5-mm data sets was 0.66, 0.62, 0.90 and 0.78, 0.69, 0.67 for reviewers 1, 2, and 3, respectively, using primary 3D versus 2D search (p = not significant [NS]). For neoplasmsor = 10 mm, the AUC using 2.5-mm data sets was 0.74, 0.85, 0.89 and 0.66, 0.86, 0.92 for reviewers 1, 2, and 3 using primary 3D versus 2D search (p = NS). There was no significant difference using 1.25-mm collimation. Double review using both primary 3D and 2D search yielded sensitivities of 84% (16/19) and 95% (18/19) for large neoplasms (or = 1 cm) using 2.5- and 1.25-mm data sets, respectively. Five of five (100%) adenocarcinomas were identified. The sensitivity of colonoscopy for large neoplasms was 77% (20/26) (20% [1/5] for adenocarcinoma).No advantage exists for 1.25- or 2.5-mm slice thickness or for primary 3D versus 2D search at CTC. Double review using primary 3D (virtual dissection) and 2D search reduces interobserver variability and competes with colonoscopy for the detection of large lesions.

Our purpose was to determine the prevalence of polyps that are invisible on CT colonography (CTC) in a population previously screened for colorectal neoplasms. Differences in the prevalence of occult polyps in various populations might help explain the discordant reported sensitivities for polyp detection in published reports of CTC.Seventy-five consecutive patients who had been previously screened for polyps underwent same-day colonoscopy and CTC. Many of the patients had personal histories of previous polypectomies and were undergoing surveillance colonoscopy. The scans were interpreted prospectively by an experienced radiologist. Polyps missed prospectively on CTC were analyzed retrospectively by three experienced radiologists and categorized as perception errors (visible in retrospect), technical errors (e.g., obscured by feces or fluid), or occult (invisible).Thirty polyps 5 mm or larger were found at colonoscopy, 18 of which were missed prospectively on CTC. Of the 18 missed polyps, 12 could not be identified in retrospect, even though they were located in clean, dry, well-distended colonic segments. These were classified as occult. Ten of the 12 occult polyps showed flat morphology on review of colonoscopy video recordings. Of the remaining six missed polyps, two were classified as perception errors, two as technical errors, and two as a combination of technical and perception error.In this population, colonographically occult polyps were common and accounted for more detection failures than perception errors and technical errors combined. The high prevalence of occult polyps may be explained by the fact that previous screening may have led to removal of easy-to-see polyps, creating a study population with a higher percentage of hard-to-see polyps.

Background & Aims: In a population reflective of a screening setting, our aim was to compare the relative sensitivity and specificity of computed tomography (CT) colonography with double-contrast barium enema (DCBE) for detection of colorectal polyps and to assess the added value of double reading at CT colonography, using endoscopy as the arbiter. Methods: This prospective, blinded study comprised 837 asymptomatic persons at higher than average risk for colorectal cancer who underwent CT colonography followed by same-day DCBE. Examinations with polyps ≥5 mm in diameter were referred to colonoscopy. Results: CT colonography readers detected 56%–79% of polyps ≥10 mm in diameter. In comparison, the sensitivity at DCBE varied between 39% and 56% for the 31 polyps ≥1 cm. All of the readers detected more polyps at CT colonography than DCBE, but the difference was statistically significant for only a single reader ( P = 0.02). Relative specificity for polyps ≥10 mm on a per-patient basis ranged from 96% to 99% at CT colonography, and 99%–100% at DCBE. Doubly read CT colonography detected significantly more polyps than DCBE (81% vs. 45% for polyps ≥1 cm [ P = P ≤ 0.01]). Conclusions: Double-read CT colonography is significantly more sensitive in detecting polyps than single-read double contrast barium enema. DCBE was significantly more specific than CT colonography.

We examined potential factors that may cause false-negative results on CT colonography examinations.In this prospective and retrospective study, 500 asymptomatic patients at high risk for colorectal cancer underwent CT colonography and colonoscopy. Each CT data set was interpreted by two independent observers, who were unaware of endoscopic findings, using a method of searching through enlarged axial images to detect intraluminal lesions. Another observer identified and characterized lesions missed at prospective interpretation. Polyps were assessed for size, method of visualization, intrinsic and extrinsic features, and examination quality.We found 116 polyps at least 5 mm in diameter, 54 (47%) of which were missed by at least one of the prospective observers. Polyps seen in only one position were missed more often than polyps seen in both supine and prone positions (84% vs 50%, p0.01). Polyps located in suboptimally prepared colonic segments or along a thickened colonic wall were more frequently missed (p = 0.02 and p = 0.05, respectively). Endoscopic morphology and irregular surface contour were associated with missed lesions of all sizes (p = 0.03 and p = 0.04, respectively). Rounded intraluminal lesions were detected more often than other morphologies on CT (p = 0.04).Factors that influence the likelihood that a polyp may be missed at interpretation of CT colonography include being seen only in one position, having flat endoscopic or CT morphology, having surface irregularity, and being located in a poorly prepared segment or along a thickened colonic wall. Understanding these features should lead to improved polyp detection on CT colonography.

No multicenter study has been reported evaluating the performance and interobserver variability of computerized tomographic colonography. The aim of this study was to assess the accuracy of computerized tomographic colonography for detecting clinically important colorectal neoplasia (polypsor=10 mm in diameter) in a multi-institutional study.A retrospective study was developed from 341 patients who had computerized tomographic colonography and colonoscopy among 8 medical centers. Colonoscopy and pathology reports provided the standard. A random sample of 117 patients, stratified by criterion standard, was requested. Ninety-three patients were included (47% with polypsor=10 mm; mean age, 62 years; 56% men; 84% white; 40% reported colorectal symptoms; 74% at increased risk for colorectal cancer). Eighteen radiologists blinded to the criterion standard interpreted computerized tomography colonography examinations, each using 2 of 3 different software display platforms.The average area under the receiver operating characteristic curve for identifying patients with at least 1 lesionor=10 mm was 0.80 (95% lower confidence bound, 0.74). The average sensitivity and specificity were 75% (95% lower confidence bound, 68%) and 73% (95% lower confidence bound, 66%), respectively. Per-polyp sensitivity was 75%. A trend was observed for better performance with more observer experience. There was no difference in performance across software display platforms.Computerized tomographic colonography performance compared favorably with reported performance of fecal occult blood testing, flexible sigmoidoscopy, and barium enema. A prospective study evaluating the performance of computerized tomography colonography in a screening population is indicated.

Background & Aims: The influence of preoperative staging of rectal carcinoma on therapeutic decisions is uncertain. The use of fine-needle aspiration (FNA) of perirectal nodes in this setting has not been evaluated. The aim of this prospective, blinded study of patients with rectal cancer was to assess the impact of preoperative staging on treatment decisions and compare the tumor (T), nodal (N) staging performance characteristics of pelvic computed tomography (CT), rectal endoscopic ultrasonography (EUS), and EUS FNA. Methods: Eighty consecutive patients with newly diagnosed rectal cancer were prospectively evaluated. Therapy decisions were recorded after sequential disclosure of staging information to the patient's surgeon. Results : In 31% of patients (95% confidence interval, 21%–42%), EUS staging information changed the surgeon's original treatment plan based on CT alone. The further addition of FNA changed therapy in one patient. T staging accuracy was 71% (CT) and 91% (EUS) ( P = 0.02); N staging accuracy was 76% (CT), 82% (EUS), and 76% (EUS FNA) ( P = NS). Conclusions: Preoperative staging with EUS results in more frequent use of preoperative neoadjuvant therapy than if staging was performed with CT alone. The addition of FNA only changed the management of one patient, whereas FNA did not significantly improve N staging accuracy over EUS alone. FNA seems to offer the most potential for impacting management in those patients with early T stage disease, and its use should be confined to this subgroup of patients. EUS is more accurate than CT for determining T stage of rectal carcinoma. GASTROENTEROLOGY 2002;123:24-32

We describe an unusual presentation of Enterobius vermicularis infestation. Computed tomography showed wall thickening in the distal ileum and cecum, with fat stranding, ascites and mesenteric adenopathy. Fluoroscopic examination confirmed distal ileal transverse fold thickening. Isolation of Enterobius vermicularis in stool and biopsy confirmed the diagnosis. Enterobius should be included among the causes of eosinophilic ileocolitis.

To determine the frequency of extracolonic findings at computed tomographic (CT) colonography and the effect of these findings on subsequent patient treatment and cost.Conventional transverse CT colonographic scans in 264 consecutive patients were evaluated independently by two radiologists. Extracolonic findings were classified as having high, moderate, or low clinical importance. The effect of CT findings on patient treatment was assessed with chart review. The cost of additional examinations was calculated by using 1999 Medicare reimbursements.Thirty (11%) patients had highly important extracolonic findings, which resulted in further examinations in 18 (7%) patients, including ultrasonography in 10, CT in 13, and intravenous pyelography in one. Six patients underwent surgery because of incidentally discovered CT colonographic findings. Two patients with findings of moderate or low importance underwent additional imaging. A total of $7,324 was required for work-up for extracolonic findings (mean of an additional $28 per examination). Three extracolonic malignancies were overlooked at CT colonography.Additional work-up of extracolonic CT colonographic findings was relatively infrequent but was often worthwhile when performed for lesions classified as highly important. The evaluation of extracolonic structures at CT colonography has definite limitations with regard to solid organs but can help detect serious disease without substantially increasing the cost per patient.

To estimate the sensitivity and specificity of computed tomographic (CT) colography in detection of colorectal polyps and to compare these findings with those at axial CT.In 70 consecutive patients, CT colography and colonoscopy were performed. Helical axial CT images and CT colographic images (multiplanar two- and three-dimensional endoluminal images) were evaluated separately by two radiologists blinded to results from colonoscopy and other imaging studies. Findings were compared with those at colonoscopy, which was the standard.The sensitivity and specificity for the two observers with CT colography averaged 75% and 90% in patients with adenomas 10 mm in diameter or larger, 66% and 63% in patients with adenomas 5 mm in diameter or greater, and 45% and 80% for patients with adenomas less than 5 mm in diameter, respectively. Sensitivity and specificity with axial CT were lower than those with CT colography (58% and 74%, respectively) in patients with adenomas 10 mm in diameter or larger.Compared with axial CT, CT colography appears to have superior sensitivity and specificity in detection of clinically important colorectal adenomas. Early performance of CT colography seems promising for detection of colorectal polyps 5 mm and larger.

The purposes of this study were to assess the prevalence of colonic lesions detected at barium enema in a community practice, to compare the findings at barium enema between patients who are asymptomatic and have no known risk factors for colorectal cancer (screening group) and patients who have symptoms of colonic disease or have known risk factors, and to determine if a questionnaire about symptoms and risk factors is an appropriate screening tool.A self-administered questionnaire about colorectal symptoms and risk factors was given to 1779 patients scheduled for barium enema examination. On the basis of their responses, patients were divided into three groups: screening group (asymptomatic, without risk factors), symptomatic, and asymptomatic with risk factors. Each patient underwent a fluoroscopic barium enema. We then compared the results (number, histologic type, size of lesion(s), location in the colon, and Patient's age) and risk factors among the three groups.At least one lesion within the colorectum was found in 166 (9%) of 1779 patients at combined proctosigmoidoscopy and barium enema. The prevalence of lesions in the 111 patients with at least one lesion above the rectum at barium enema was 4% (32 of 738) for the screening group, 8% (38 of 476) for asymptomatic patients with risk factors, and 7% (41 of 565) for symptomatic patients (p = .015 when comparing the prevalence in the screening group with the prevalences in the other two groups). Twenty-nine percent of all colonic lesions were found in the screening group. Among the asymptomatic patients, risk factors that included a history of colorectal polyps and advanced age were associated with a significantly higher prevalence of colonic polyps found at barium enema. In the symptomatic group, if patients with histories of polyps were excluded, we were unable to identify other risk factors that led to a significantly higher prevalence of polyps.Asymptomatic patients without known risk factors have a significantly lower prevalence of colonic polyps than either symptomatic patients or patients with risk factors alone. Despite this lower prevalence, 29% of all lesions in our series were in the screening group. Assessment of risk factors through a patient questionnaire was not helpful in identifying a group of patients with a higher prevalence of lesions--except for a history of polyps. Management decisions based on a patient questionnaire should be approached with caution. When low-risk patients are denied screening examinations, a significant number of lesions will be missed.

The purpose of this study was to evaluate the sensitivity and specificity of globular enhancement for differentiating hepatic hemangiomas from hypervascular metastases on single-pass, contrast-enhanced CT scans. Globular enhancement was defined as enhancing nodules less than 1 cm seen within a lesion.Fifty CT examinations were retrospectively evaluated in a blinded fashion by two independent reviewers. The CT studies were done with nonhelical technique after the IV injection of 150 ml of contrast material. The series included 25 patients with histologically proven hypervascular hepatic metastases (carcinoid, islet cell carcinoma, and leiomyosarcoma) and 25 patients with clinically proven hepatic hemangiomas. Patients with hemangiomas were clinically stable for at least 2 years after the CT studies. A single lesion was isolated from the first-pass, contrast-enhanced portion of each examination; the remainder of the examination was excluded from the review to minimize reviewer bias. Each lesion was evaluated for (1) the presence or absence of globular enhancement (defined as enhancing nodules less than 1 cm seen within a lesion), (2) the density of globular enhancement relative to that of the aorta, (3) the degree of border definition (well or poorly marginated), and (4) the presence or absence of a hypodense halo. A diagnostic impression was then recorded for each lesion.Globular enhancement was 88% sensitive and 84-100% specific for differentiating hepatic hemangiomas from hypervascular metastases (p.001). A mean of 62% of hemangiomas showed globular enhancement isodense relative to that of the aorta; none of the metastases showed globular, isodense enhancement. The majority of the metastases showed nonglobular enhancement (mean, 92%). The reviewers showed 84% agreement in the identification of (1) globular enhancement in hemangiomas, (2) lack of globular enhancement in metastases, and (3) globular enhancement in the combined set of all lesions. Neither the presence of a hypodense halo nor the degree of border definition was significant in distinguishing between the two groups of lesions. The reviewers showed 96% agreement in the categorization of metastases and 76% agreement in the categorization of hemangiomas. There was 86% agreement in the categorization of all lesions. Overall, reviewers diagnosed a mean of 89% of lesions correctly. A mean of 98% of metastases and a mean of 80% of hemangiomas were diagnosed correctly.Globular enhancement is highly sensitive (88%) and specific (84-100%) for differentiating hepatic hemangiomas from hypervascular metastases on single-pass, contrast-enhanced CT scans.

Background & Aims: Recurrence of Crohn's disease frequently occurs after surgery. A randomized controlled trial was performed to determine if mesalamine is effective in decreasing the risk of recurrent Crohn's disease after surgical resection is performed. Methods: One hundred sixty-three patients who underwent a surgical resection and had no evidence of residual disease were randomized to a treatment group (1.5 g mesalamine twice a day) or a placebo control group within 8 weeks of surgery. The follow-up period was a maximum of 72 months. Results: The symptomatic recurrence rate (symptoms plus endoscopic and/or radiological confirmation of disease) in the treatment group was 31% (27 of 87) compared with 41% (31 of 76) in the control group ( P = 0.031). The relative risk of developing recurrent disease was 0.628 (90% confidence interval, 0.40-0.97) for those in the treatment group ( P = 0.039; one-tail test) using an intention-to-treat analysis and 0.532 (90% confidence interval, 0.32-0.87) using an efficacy analysis. The endoscopic and radiological rate of recurrence was also significantly decreased with relative risks of 0.654 (90% confidence interval, 0.47-0.91) in the effectiveness analysis and 0.635 (90% confidence interval, 0.44-0.91) in the efficacy analysis. There was only one serious side effect (pancreatitis) in subjects in the treatment group. Conclusions: Mesalamine (3.0 g/day) is effective in decreasing the risk of recurrence of Crohn's disease after surgical resection is performed.

Cicatricial pemphigoid (CP) (benign mucous membrane pemphigoid) is a rare, blistering disease of skin and mucous membrane. The disease rarely extends to involve the esophagus, and there are only a few cases reported in the radiological literature. The aims of this study were to document the frequency of esophageal involvement and to describe the findings on upper GI barium studies. A total of 197 patients with CP were seen at our institution from 1981 to 1991. The clinical and radiological findings of these patients were reviewed and compared with findings reported in the literature. Esophageal involvement was documented in seven patients. Cervical esophageal webs were found in five of the seven patients. Two patients had single esophageal webs while three had multiple webs. Frank strictures of the esophagus were also seen in five patients. These were most common in the cervical esophagus, but strictures were also found in the mid and lower esophagus. Two of the strictures resulted in significant dysphagia and required multiple endoscopic dilatations. One of the dilatations was complicated by mucosal injury, and follow-up barium examination showed dissection of the esophageal mucosa from the cervical esophagus to the esophagogastric junction. One patient demonstrated intramural pseudodiverticulosis in the cervical esophagus. Functional disturbances demonstrated on barium studies included tracheal aspiration in two patients and nasopharyngeal reflux in three. CP involves the esophagus in approximately 5% of cases. The hypopharynx and cervical esophagus are most commonly involved, but any portion of the esophagus may be involved, and multiple levels of involvement may be seen. Cervical esophageal webs, often multiple or complex, are the most common appearance on barium studies, but frank strictures are also found. Secondary manifestations of esophageal involvement include nasopharyngeal reflux, tracheal aspiration, and intramural pseudodiverticulosis.

Virtual dissection is a three-dimensional (3D) display technique for CT colonography that could potentially reduce interpretation times. With virtual dissection, the 3D model of the colon is "sliced" open along a centerline trace, rendering a 360° view of the endoluminal mucosa as a rectangular image. However, one must be familiar with several pitfalls and limitations to avoid errors in interpretation. One of the main limitations is the anatomic distortion that results. Polyp shape and colonic folds can be distorted and colonic or polyp mobility can lead to mischaracterization of polyps. Distorted folds, which frequently occur at flexures, can mimic polyps. Annular constricting masses can lead to skip areas, where the abnormality is not displayed. Various entities including diverticula and stool can mimic polyps at virtual dissection. Finally, technical errors such as an inadequate centerline trace can render a polyp occult. The purpose of this review is to demonstrate the spectrum of appearances of polyps at virtual dissection, with an emphasis on more difficult to detect polyps. In addition, 10 interactive virtual dissection quiz cases are presented along with corresponding two-dimensional and 3D endoluminal fly-through views.

In this report, our objectives are to introduce the term "ischemic cholangitis" as an etiologic designation and to describe its manifestations. Herein we use the label "ischemic cholangitis" as a collective term for ischemic bile duct necrosis, cholangitis caused by ischemia but without necrosis, and biliary fibrosis as a manifestation of ischemic damage. The condition was observed in 12 allografts, either at the time of retransplantation (9 cases) or at autopsy (3 cases). Ischemic cholangitis involved primarily perihilar extrahepatic and intrahepatic bile ducts. The findings included duct necroses (eight cases), strictures (four cases), and cholangiectases (four cases); some of these features coexisted. In addition, complicating ascending cholangitis and cholangitic abscesses were noted in three cases. Ischemic cholangitis was caused by hepatic artery thrombosis (in nine patients) or stenosis (in one) or by occlusion of parabiliary arteries by fibrointimal proliferations, probably attributable to old thromboses (in two, in conjunction with associated foam cell arteriopathy in one). Biopsy specimens before retransplantation or autopsy were obtained in 11 patients, only 1 of whom had an infarct as direct evidence of ischemia. Nine patients had evidence of biliary obstruction or bile flow impairment; in two cases, specimens were normal or nondiagnostic relative to cholangitis. Features of cellular rejection associated with the manifestations of bile flow impairment and ischemia were noted in five cases. Thus, biopsy features that suggest biliary obstruction, with or without cellular rejection, may be a manifestation of ischemic cholangitis. We conclude that ischemic cholangitis is an important cause of cholestatic graft failure but that this type of cholangitis is difficult to diagnose because of its misleading biopsy manifestations.

Both colonoscopy and barium enema are important techniques for examining the colon for polyps and cancer. They are approximately equally sensitive in detecting polypoid lesions of 7 to 10 mm or larger. A major limitation of colonoscopy is that the cecum cannot be visualized in 10 to 36% of cases. The comparable accuracy for detecting significant lesions, greater safety, and greater cost-effectiveness of barium enema favor its use in most patients.

Primary sclerosing cholongitis is an increasingly recognized chronic cholestatic liver disease. It frequently occurs in association with chronic ulcerative colitis and is characterized by inflammation and fibrosis of the intrahepatic and extrahepatic bile ducts. The cause is unknown, although many mechanisms have been considered, including infectious, toxic, and immunologic. The prognosis varies. No adequate treatment exists, although a number of potential treatments have been evaluated in uncontrolled trials, and the results of controlled trials have only recently been reported. Liver transplantation has recently been shown to be an effective treatment for end-stage disease. These various advances in our understanding of primary sclerosing cholangitis are reviewed.

We identified and analyzed 45 patients with asymptomatic primary sclerosing cholangitis to better understand the natural history of this disease. Disease progression was monitored at regular intervals for the development of symptoms and physical signs as well as changes in liver biochemistry, cholangiography, and liver histology. During a median follow-up of 75.2 mo, 34 patients (76%) had evidence of disease progression. Fourteen patients (31%) developed liver failure which resulted in death or referral for liver transplantation. For patients with primary sclerosing cholangitis, survival curves computed using the Kaplan-Meier method were significantly worse than expected when compared to age-, sex-, and race-specific survival rates for the United States north central population (p less than 0.001). These findings indicate that primary sclerosing cholangitis is generally a progressive disease with considerable morbidity and mortality even when detected before the onset of symptoms.

The newly recognized class of 5-hydroxytryptamine receptors (5HT3) may be involved in the induction of nausea, since their pharmacological antagonists are effective against emesis induced by chemotherapy. 5HT3 receptors are present on enteric neurons, and 5HT3 blockers may produce mild constipation; we thus hypothesized that 5HT3 receptors would modulate colonic motility. To determine if GR 38032F, a selective 5HT3 antagonist known to have antiemetic effects, influences colonic transit in health, a randomized, double-blind, placebo-controlled crossover study was performed. Using a radiopaque marker technique, colonic transit was quantified in 39 healthy volunteers (19 men, 20 nonpregnant women) 18-70 years of age. On a standard 25-g fiber diet, 16 mg of GR 38032F was given orally thrice daily. Gastrointestinal peptides (peptide YY, human pancreatic polypeptide, neurotensin, motilin, gastrin-cholecystokinin, substance P) were also measured in plasma fasting and postprandially. Mean total colonic transit time on placebo was 27.8 hr, while on GR 38032F it was 39.1 hr (P less than 0.0005). Transit times through the left colon (P less than 0.0005) and rectosigmoid (P less than 0.05) were prolonged by the drug, but right colonic transit was not significantly altered. Transit times did not correlate with age or gender, but subjects with shorter transit times were significantly more affected than were those with longer transit times. The peak release of peptide YY was minimally decreased following GR 38032F (P less than 0.01), but the peak and integrated postprandial responses of human pancreatic polypeptide, neurotensin, motilin, gastrin-cholecystokinin, and substance P were not significantly altered by the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

We report the findings on barium examinations from 20 patients with eosinophilic gastroenteritis. Thickening of mucosal folds in the stomach (seven cases), small intestine (four patients), or both (two cases) was the most common finding. Nodular fold enlargement was present in the stomach in three cases and in the small intestine in four cases. One patient had discrete antral polyps. Multiple gastric erosions, to our knowledge not previously reported in eosinophilic gastroenteritis, were seen in two patients. Although the stomach and small bowel are most commonly affected, any portion of the gastrointestinal tract may be involved.

The natural history of untreated colonic polyps is uncertain. A retrospective review of Mayo Clinic records from a 6-yr period just before the advent of colonoscopy identified 226 patients with colonic polyps greater than or equal to 10 mm in diameter in whom periodic radiographic examination of the colon was elected over excisional therapy. In all patients, follow-up of polyps spanned at least 12 mo (mean, 68 mo; range, 12-229 mo) and included at least two barium enema examinations (mean, 5.2; range, 2-17). During the follow-up period, 83 polyps (37%) enlarged. Twenty-one invasive carcinomas were identified at the site of the index polyp at a mean follow-up of 108 mo (range, 24-225 mo). Actuarial analysis revealed that the cumulative risk of diagnosis of cancer at the polyp site at 5, 10, and 20 yr was 2.5%, 8%, and 24%, respectively. In addition, 11 invasive cancers were found at a site remote from the index polyp during the same follow-up period. These data further support the recommendation for excision of all colonic polyps greater than or equal to 10 mm in diameter. Periodic examination of the entire colon is recommended in this group of patients to identify neoplasms arising at a site remote from the index polyp. Although this study has limitations inherent to any retrospective analysis, comparable prospective data are unlikely to be available in the future because of the current widespread availability of colonoscopy.

Primary sclerosing cholangitis is a progressive, ultimately fatal, chronic hepatobiliary disorder for which no effective medical or surgical therapy now exists. The syndrome occurs most commonly in young men and is characterized by a chronic cholestatic syndrome, frequent association with chronic ulcerative colitis, hepatic copper overload, a paucity of serologic markers, and characteristic abnormalities in some liver-biopsy specimens and most cholangiograms. The natural history of the syndrome is unclear; the disease is likely to progress slowly and relentlessly, over a decade or longer, from an asymptomatic stage to a condition characterized by symptoms of cholestasis and complicated by cirrhosis, portal hypertension, and possibly carcinoma of the bile ducts. Screening techniques based on automated biochemical analyses are likely to lead to a diagnosis of primary sclerosing cholangitis in increasing numbers of patients, perhaps in the early, preicteric stage. An increased level of serum alkaline phosphatase in a young man, particularly if he has chronic ulcerative colitis, should strongly suggest the presence of this syndrome and the need for additional diagnostic studies. Endoscopic retrograde cholangiography and liver biopsy should be considered under these circumstances.

Transit times of radiopaque markers through the human gut were measured by published techniques and compared with a simplified method. Three sets of distinctive markers were ingested by 24 healthy persons on 3 successive days. In the first part of the study, daily abdominal x-rays were taken and individual stools were collected for radiography. Mouth-to-anus transits were assessed from the fecal output of markers and mean colonic and segmental colonic transits were calculated from the daily radiographs. These established methods were then compared with estimates of total colonic and segmental transits based on a single abdominal film, taken on the fourth day. The single-film technique correlated well with values obtained from the previous, but more inconvenient, methods. Using the simpler approach, colonic transit was assessed in 49 additional healthy subjects, for a total group of 73. Total colonic transit was 35.0 +/- 2.1 h (mean +/- SE); segmental transits was 11.3 +/- 1.1 h for the right colon, 11.4 +/- 1.4 h for the left colon, and 12.4 +/- 1.1 h for the rectosigmoid. Men had significantly shorter transits for the whole colon than did women (p less than 0.05), and this difference was apparent to some extent in the right (p = 0.06) and left colon (p = 0.07) but not in the rectosigmoid. Age did not influence transit significantly nor did a small dose of supplemental fiber. The technique is simple, convenient for clinical usage, and reduces the exposure to radiation to acceptable levels. There should be a role for this approach in the evaluation of colonic transit in selected patients.

The purpose of this study was to evaluate the usefulness of CT and sonography as procedures complementary to cholangiography in the detection and staging of cholangiocarcinoma. The studies of 42 patients with pathologically proved cholangiocarcinoma and preoperative CT (26 patients), sonography (30 patients), and cholangiography (31 patients) were reviewed blindly and retrospectively. The tumor was shown by CT in 69%, by sonography in 47%, and by cholangiography in 97% of patients. Three radiographic types of cholangiocarcinoma were identified: infiltrating stenotic (69%), bulky exophytic (19%), and polypoid intraluminal (12%). CT correctly staged 54%, sonography 50%, and cholangiography 58% of tumors as resectable (40%) or unresectable (60%). The sensitivities in detecting unresectability with CT, sonography, and cholangiography were 44%, 19%, and 43%, respectively; specificities were 78%, 100%, and 100%, respectively. CT and sonography combined with cholangiography increased the sensitivities to 64% and 50%, respectively. CT and sonography were complementary to cholangiography because they helped determine the extrabiliary extent of these tumors and therefore provided information on resectability.