Introducing a novel approach of network oriented analysis of ERPs, demonstrated on adult attention deficit hyperactivity disorder.

OBJECTIVE: Introducing a network-oriented analysis method (brain network activation [BNA]) of event related potential (ERP) activities and evaluating its value in the identification and severity-grading of adult ADHD patients. METHODS: Spatio-temporal interrelations and synchronicity of multi-sited ERP activity peaks were extracted in a group of 13 ADHD patients and 13 control subjects for the No-go stimulus in a Go/No-go task. Participants were scored by cross-validation against the most discriminative ensuing group patterns and scores were correlated to neuropsychological evaluation scores. RESULTS: A distinct frontal-central-parietal pattern in the delta frequency range, dominant at the P3 latency, was unraveled in controls, while central activity in the theta and alpha frequency ranges predominated in the ADHD pattern, involving early ERP components (P1-N1-P2-N2). Cross-validation based on this analysis yielded 92% specificity and 84% sensitivity and individual scores correlated well with behavioral assessments. CONCLUSIONS: These results suggest that the ADHD group was more characterized by the process of exerting attention in the early monitoring stages of the No-go signal while the controls were more characterized by the process of inhibiting the response to that signal. SIGNIFICANCE: The BNA method may provide both diagnostic and drug development tools for use in diverse neurological disorders.

Small flat umbilicated tumors of the colon: radiographic and pathologic findings.

OBJECTIVE: We describe the radiographic and pathologic findings of small flat umbilicated tumors of the colon detected on double-contrast barium enema examinations performed in a Western population. CONCLUSION: Unlike those reported by Japanese authors, the small flat umbilicated tumors of the colon in our patients were usually hyperplastic polyps, previously called "inverted hyperplastic polyps." Nevertheless, colonoscopy with excisional biopsy is warranted for such tumors detected on double-contrast barium enema examinations because of the small possibility that these tumors represent adenoma or even early adenocarcinoma.

Diagnosis of colorectal neoplasms at double-contrast barium enema examination.

The double-contrast barium enema examination has been recognized as an option for colorectal cancer screening in Americans with average risk who are greater than 50 years of age. The purpose of this article is to review the principles for diagnosing colorectal neoplasms on double-contrast images and the spectrum of findings associated with these lesions. Colonic polyps can be sessile or pedunculated; their appearance depends on whether they are located on the dependent or nondependent wall of the bowel. Villous tumors may be flat, lobulated lesions, also known as "carpet" lesions, that are characterized by a finely nodular or reticular surface pattern, without a discrete mass. Colonic carcinomas may manifest as plaquelike, polypoid, semiannular ("saddle") or annular lesions. Colonic neoplasms sometimes are more difficult to detect in the region of the ileocecal valve or the distal rectum or in patients with severe diverticulosis. Careful double-contrast technique and meticulous scrutiny of the images therefore are required to optimize detection of these lesions.

Double-contrast barium enema examination technique.

This review article presents the principles for performing a safe, comfortable, and accurate double-contrast barium enema examination. The procedure is a flexible examination in which the fluoroscopist interacts with the patient, the controls of the fluoroscope, and the image on the television monitor. During a double-contrast examination, images of the colon are created by manipulating the patient, the barium pool, and the amount of air insufflated into the rectum. Fluoroscopy is essential for guiding the radiologist to obtain spot images with adequate technical factors. The fluoroscopist analyzes the luminal contour, the barium-coated mucosal surface en face, and the barium pool to detect abnormalities in the colon. With careful technique, a high-quality examination can be performed in most patients.

Gastrointestinal imaging: a systems analysis comparing digital and conventional techniques.

OBJECTIVE: The purpose of this study was to compare digital and conventional methods of gastrointestinal imaging based on the cost of image storage and estimated overall costs, radiation exposure to the patient, and duration of the examination. MATERIALS AND METHODS: Our study sample consisted of 128 patients who underwent conventional gastrointestinal studies (64 double-contrast upper gastrointestinal examinations and 64 double-contrast barium enemas) and 139 patients who underwent digital gastrointestinal studies (66 double-contrast upper gastrointestinal examinations and 73 double-contrast barium enemas). The number of images and films for each study was recorded, and the mean cost of image storage and the estimated overall costs for digital versus conventional studies were calculated. Both the duration of fluoroscopy and the time from start to completion of the study were obtained from our radiology information system. From these data, we calculated mean radiation exposure to the patient and the duration of the examination. Finally, referring physicians completed a questionnaire about their level of satisfaction with paper prints generated from digital gastrointestinal studies. RESULTS: When digital studies were compared with conventional studies, the mean cost of image storage decreased by 45% and the estimated overall 10-year costs decreased by 8%. The mean number of spot images increased by 8% for upper gastrointestinal examinations and by 25% for barium enema examinations, whereas the mean duration of fluoroscopy decreased by 4% and by 10%, respectively. As a result, radiation exposure to patients increased by only 2%, a difference that did not approach statistical significance. Finally, the mean duration of examinations decreased by 24% for upper gastrointestinal examinations and by 33% for barium enemas. Approximately 85% of the physicians who completed the questionnaires indicated that they reviewed the paper prints generated from digital studies and that they would like to continue receiving them. CONCLUSION: Digital gastrointestinal imaging systems are associated with higher initial costs than conventional systems, but the long-term costs of these digital imaging systems are slightly less because of the lower cost of image storage, and radiation exposure to patients is comparable. The shorter duration of digital examinations is a potential benefit of this technology, allowing improved patient throughput. Finally, referring physicians have a high level of satisfaction with paper prints generated from digital imaging.

Total proctocolectomy and ileoanal pouch: the role of contrast studies for evaluating postoperative leaks.

BACKGROUND: To assess the role of contrast enemas for the evaluation of leaks in symptomatic and asymptomatic patients after the first stage of restorative proctocolectomy. METHODS: We reviewed the findings of 59 contrast enemas in 40 patients who underwent total proctocolectomy with creation of an ileoanal pouch and a proximal diverting ileostomy. Thirty-seven patients initially underwent routine contrast studies of the ileoanal pouch, and three underwent contrast studies because of suspected fistulas or obstruction. Medical records were also reviewed to determine the clinical presentation and course of these patients. RESULTS: Of 37 patients who underwent routine postoperative contrast enemas, 33 (89%) had normal studies, three (8%) had clinically silent leaks (including two blind-ending tracks from the ileoanal anastomosis and one from the pouch), and one (3%) had pouchitis. In all three patients with unsuspected leaks, ileostomy closure was delayed. In two other patients with abdominal pain and fever, contrast enemas revealed leaks from the ileoanal pouch and distal ileum, respectively. The remaining patient had a contrast enema because of abdominal pain and distention; this patient had a distal ileal obstruction due to adhesions. CONCLUSIONS: Routine postoperative contrast studies revealed clinically silent leaks from the ileal J pouch or ileoanal anastomosis in three of 37 patients (8%) after the first stage of restorative proctocolectomy. Our findings suggest that routine contrast enema can detect clinically silent leaks after this surgery.

Value of digital fluoroscopy for the diagnosis of pneumatosis coli.

Two cases are presented of benign pneumatosis coli diagnosed on digital fluoroscopic barium enema examinations, in which the gas-filled cysts in the colonic wall were only recognized by postprocessing of the images (i.e. increasing the brightness and contrast settings) at the computer workstation. When digital barium enemas are performed, we therefore recommend image postprocessing to evaluate polypoid lesions in order to differentiate pneumatosis coli from true colonic neoplasms.

Colon cancer: morphology detected with barium enema examination versus histopathologic stage.

PURPOSE: To determine the relationship between the morphology of colon carcinomas detected with barium enema examination and the cancer stage. MATERIALS AND METHODS: Clinical, radiographic, endoscopic, surgical, and histopathologic findings were retrospectively reviewed in 152 patients with colon cancer detected with barium enema examination during a 2-year period. RESULTS: Eighty-six patients (57%) had lesions in the rectum and sigmoid and descending colon, and 66 (43%) patients had lesions more proximally in the colon. Lesions on the right side of the colon were less likely to cause symptoms than those on the left side. Eighty-one patients (53%) had annular or semiannular lesions, 57 (38%) had polypoid lesions, and 14 (9%) had plaquelike or carpet lesions. Six patients (4%) had Dukes stage A lesions; 84 (55%), Dukes stage B lesions; 42 (28%), Dukes stage C lesions; and 20 (13%), Dukes stage D lesions. CONCLUSION: Annular or semiannular carcinomas had higher rates of serosal invasion and lymph node metastasis than polypoid carcinomas, but the rates of liver metastases were comparable.

The effects of distention of the colon during air-contrast barium enema on colonic morphology: anatomic correlation.

Radiologic and pathologic findings are snapshots of disease processes that may vary with a host of dynamic variables. This pictorial essay shows how the presence and visibility of the innominate grooves of the colon are a function of colonic distention. This article also shows how each layer of the colonic wall, including the epithelium, muscularis mucosae, and muscularis propria, changes dramatically in thickness with varying degrees of colonic distension. These anatomic changes are documented by barium enema radiography, specimen radiography, dissecting photomicrography, and histology. These observations have important implications for the interpretation of radiologic and pathologic findings in both normal and diseased states.

Enteroclysis in the evaluation of obscure gastrointestinal bleeding.

OBJECTIVE: The diagnostic yield of enteroclysis was retrospectively evaluated for patients with obscure bleeding from the gastrointestinal tract. MATERIALS AND METHODS: A total of 128 patients with obscure gastrointestinal bleeding were referred to our department for enteroclysis between 1988 and 1993. The original radiologic reports were reviewed to determine the radiographic findings in these patients. The radiographic findings then were correlated with medical, surgical, and pathologic findings. RESULTS: Thirty-two patients had lesions found at enteroclysis. Nineteen of those patients had confirmation of the radiographic diagnosis, primarily by pathologic examination of the surgical specimen. Five other patients were found at surgery to have had false-positive diagnoses at enteroclysis. Eight patients ceased to bleed without pathologic corroboration, but their clinical presentation and course supported the radiographic diagnosis. Thus, 27 (21%) of the 128 patients had confirmed or highly probable lesions seen at enteroclysis as the cause of obscure gastrointestinal bleeding. Seventeen patients (13%) had tumors involving the small bowel, and three (2%) had arteriovenous malformations in the jejunum. CONCLUSION: This study corroborates earlier reports that enteroclysis is a useful diagnostic test for examining the small intestine in patients with obscure gastrointestinal bleeding.

Polypoid lesions at the anorectal junction: barium enema findings.

Although the anorectal junction is easily accessible, this area may be difficult to evaluate both radiologically and endoscopically because it is relatively collapsed. This pictorial essay illustrates the barium enema radiographic findings and reviews the radiologic and endoscopic pitfalls in the diagnosis of lesions of the anorectal junction.

Bowler-hat sign: a simple principle for differentiating polyps from diverticula.

The bowler-hat sign has been described both with colonic polyps and with diverticula. The authors describe a simple principle for evaluating a bowler-hat sign in order to determine whether it is caused by a polyp or a diverticulum. If the bowler hat points toward the center of the long axis of the bowel, it represents an intraluminal structure (ie, a polyp). If, however, it points away from the center of the long axis of the bowel, it represents an extraluminal structure (ie, a diverticulum). Only if the bowler hat is located in the midline or is directly parallel to the long axis of the bowel is it impossible to classify the abnormality as a polyp or a diverticulum. The value of this principle was confirmed with both a radiographic model and a blinded review of radiographs from 37 cases demonstrating the bowler-hat sign. When a bowler hat is present on a double-contrast barium enema examination, use of this principle provides a simple and objective means of differentiating a polyp from a diverticulum.

Adult celiac disease and its complications.

Classic radiographic findings described in adult celiac disease--lumen dilatation, flocculation of barium, hypersecretion, thickening of folds--are nonspecific or are secretion related artifacts. The small bowel enema technique and CT make it possible to demonstrate specific diagnostic features of the disease and its complications. This substantially modified approach to the diagnosis of adult celiac disease is presented together with correlative pathology. Examples of the complications of celiac disease--ulcerative jejunoileitis, lymphoma, hyposplenism, carcinoma, and the cavitary lymph node syndrome--are illustrated.

Pseudomembranous colitis with rectosigmoid sparing on barium studies.

The classic description of pseudomembranous colitis on barium enema studies is that of pancolitis with thickened haustral folds, a shaggy luminal contour, and/or mucosal plaques. However, the authors describe six patients with proved pseudomembranous colitis in whom barium studies (four double-contrast barium enema studies, one single-contrast barium enema study, and one peroral pneumocolon study) demonstrated rectosigmoid sparing with proximal colitis extending from the cecum to the sigmoid colon (three cases) or to the descending colon (three cases). In all six cases, endoscopy revealed a normal rectum or mild, nonspecific proctosigmoiditis without evidence of pseudomembranes in the rectosigmoid colon. Four patients had an atypical clinical presentation with bloody diarrhea (three cases) or minimal mucous diarrhea (one case). Thus, the diagnosis of pseudomembranous colitis may initially be suggested on barium studies in patients who have relative sparing of the rectosigmoid colon with characteristic findings more proximally in the colon.

Rectal involvement by prostatic carcinoma: barium enema findings.

A retrospective study was performed to determine the radiographic features of prostatic carcinoma invading the rectum on double-contrast barium enemas. In 11 such patients, these examinations revealed localized narrowing and/or speculation of the rectum (four cases); a smooth, extrinsic mass impression on the rectosigmoid colon (two cases); an umbilicated submucosal mass in the rectosigmoid colon (one case); and rectosigmoid narrowing with spiculated, pleated mucosal folds in the narrowed segment of bowel (four cases). Thus, most patients (64%) had localized involvement of the rectosigmoid colon with sparing of the distal rectum. The anatomic-pathologic basis for the localized spread of prostatic carcinoma to the rectosigmoid colon is illustrated on MR scans. Thus, prostatic carcinoma invading the rectum may be manifested on double-contrast barium enema by a spectrum of radiographic findings, and most patients have localized rectosigmoid involvement with sparing of the distal rectum.

Solitary rectal ulcer syndrome: a radiologic diagnosis?

The solitary rectal ulcer syndrome (SRUS) is an uncommon condition in which a solitary area of discrete ulceration is typically found on the anterior wall of the rectum. Between 1981 and 1983, we collected 8 pathologically proven cases of SRUS in which barium enema examinations had been performed (7 double-contrast, 1 single-contrast). Seven patients had rectal bleeding. On the original x-ray report, 4 cases were thought to be normal, but the pathologic tissue had been removed endoscopically in 2 of these cases prior to the radiologic study. The other 4 cases were thought to be abnormal, although the specific diagnosis of SRUS was not suggested in any case. In a blinded rereading of these 8 cases randomly interspersed with 29 other non-SRUS cases, however, the films were interpreted in light of recent radiologic experience with this condition. The same 4 cases were still thought to be normal. In the remaining 4 cases, barium enemas revealed thickened, edematous valves of Houston (3 cases) and a submucosal mass adjacent to the anal verge (1 case). The diagnosis of SRUS was suggested in all 4 cases with only 1 false-positive diagnosis due to a rectal stricture in a patient with endometriosis. Although barium enemas may be normal in patients with SRUS, the presence of thickened, edematous valves of Houston, particularly in a young patient with rectal bleeding, should suggest this condition.

Radiography of the small bowel in patients with gynecologic malignancies.

The records and radiographs of 284 patients with gynecologic malignancy were reviewed to determine the incidence and nature of small-bowel abnormalities. Seventeen percent of the patients had small-bowel studies. Twenty-four percent of patients with ovarian cancer had radiologic examination of the small bowel, and in almost all cases the abnormalities were due to metastatic disease. In patients with cervical cancer, small-bowel radiography was performed in 14% of patients, and in most cases the abnormalities were due to radiation damage. Small-bowel obstruction was found in 20 patients. In the ovarian-cancer group, all obstructions were due to metastatic disease, whereas in the cervical cancer group, obstruction was due to metastases, radiation, or adhesions. The site of obstruction was a useful differential point, since all obstructions due to radiation were in the ileum, whereas 58% of obstructions due to metastases were in the duodenum or jejunum. The radiologic studies interpreted in light of the clinical circumstances were highly accurate in determining the location and nature of small-bowel complications in these patients.

Small-bowel enema in the diagnosis of adhesive obstructions.

The small-bowel enema was evaluated in 60 patients in whom a final diagnosis of adhesive obstruction was made by surgery or on the basis of clinical findings. Distinctive radiographic and clinical features were found with single versus multiple bands. While 72% of 32 single-band obstructions were graded as severe, this grading was given to only 34% of 18 obstructions by multiple bands. Extensive adhesions were demonstrated in 10 patients and presented varied radiographic features. The radiographic diagnosis of adhesive obstruction was found to be correct in 36 (87.8%) of 41 patients in whom a surgical diagnosis could subsequently be made. However, an incorrect radiologic diagnosis of obstruction by metastases was made in five patients. They form the basis for a discussion of the differential diagnosis.