Enteroclysis: double contrast examination of the small bowel

Enteroclysis is a double contrast study of the small bowel. This procedure allows the radiologist to evaluate the small bowel for disease processes including Crohn's disease, Meckel's diverticulum, and malabsorption diseases--all disease processes sometimes missed through single contrast SBFT. Through the use of enteroclysis, the radiologist can detect mucosal fold pattern changes, ulceration of the lumen, dilation of the loops, and intussusception, which can cause an obstruction. Even though the procedure is costly and time consuming, it provides a more accurate evaluation of the small bowel.     

Demonstration of a perihepatic abscess communicating with a fistula from the small bowel on hepatobiliary imaging

Abscess formation after abdominal surgery is not an uncommon complication. It is much less common for a collection to be the result of a fistulous tract from the bowel. We describe a patient who underwent a Tc-99m hepatobiliary (Choletec) scan for the workup of a perihepatic abscess, which confirmed the presence of a fistulous tract from the small bowel to a perihepatic collection.     

Perspective: the small bowel examination in the diagnosis of Crohn's disease

Enteroclysis has been increasingly recommended for radiologic examination of the small intestine, especially for focal lesions, but also for more extensive processes such as regional enteritis. Seventy-four patients were studied who had a final clinical diagnosis of regional enteritis and who had been examined by more conventional peroral ingestion of barium suspension together with fluoroscopy and vigorous manual compression. In only two cases did the radiographic examination fail to identify proven regional enteritis; one who had an isolated ulcer at an ileorectal anastomosis and one in whom jejunal regional enteritis was mistakenly diagnosed as a mesenteric mass. Careful fluoroscopy of the small intestine combined with vigorous manual compression is a sensitive method of detecting regional enteritis.     

Primary malignant tumors in the small bowel: a comparison of the small-bowel enema and conventional follow-through examination

Of 71 patients diagnosed with primary mesenteric malignant tumors in the small bowel over a 21-year period in a community/teaching hospital, 14 underwent small-bowel follow-through, 16 underwent small-bowel enema (enteroclysis), and four patients underwent both studies preoperatively. In a retrospective study, the sensitivity of both the small-bowel enema and the conventional small-bowel follow-through examination were compared on the basis of the original radiologic interpretation. The studies were ordered by clinicians in a clinical setting. Results of the small-bowel follow-through were abnormal in 11 of 18 patients for a sensitivity of 61%, and small-bowel enema showed abnormalities in 19 of 20 patients for a sensitivity of 95% (p = .0165). The actual tumor was shown in six (33%) of 18 small-bowel follow-through studies and in 18 (90%) of 20 small-bowel enemas (p = .0005). In four patients, normal findings on conventional small-bowel follow-through were followed by abnormal findings on small-bowel enema done for the same reason. This experience suggests that the small-bowel enema is more sensitive than the conventional follow-through examination for the detection of small-bowel cancers.     

Radiographic examination of the small bowel: survey of practice patterns in the United States

PURPOSE: To obtain understanding of the current practice patterns of academic and private radiology groups in the United States in radiographic examination of the small bowel. MATERIALS AND METHODS: The survey consisted of questions about small-bowel follow-through (SBFT) examinations, including frequency of overhead radiographs, use of fluoroscopic spot images, personnel performing fluoroscopy, practice settings, and degree of specialization. By using a standard sampling technique, the country was divided into nine regions, and one state from each region was randomly selected. The survey was mailed to 452 full-time chief technologists. The responses were tabulated, and statistical analysis of the data was performed with the chi(2) test. RESULTS: Completed questionnaires were returned by 236 (52%) of 452 chief technologists; 219 (93%) respondents, 176 (80%) in private and 43 (20%) in academic groups, indicated that their group performed SBFT studies. The studies were performed by general radiologists in 205 (94%) of the 219 groups and by gastrointestinal or abdominal radiologists in 11 (5%). Studies included overhead radiographs in all 219 groups, with spot images of the terminal ileum in 201 (92%). Thirty (14%) of 219 groups routinely obtained spot images of the remaining small bowel, 104 (48%) obtained spot images only if there were questionable findings on overhead radiographs, and 82 (37%) obtained no spot images. Eighteen (8%) of 219 groups performed peroral pneumocolon examinations and 80 (37%) performed enteroclysis. CONCLUSION: The majority of radiology groups perform SBFT studies. Regardless of the practice setting, these studies usually consist of a series of overhead radiographs, with routine spot images of the terminal ileum but not of the remaining small bowel. This approach may need to be reassessed in light of the American College of Radiology standards that all accessible small-bowel loops be visualized at fluoroscopy with representative radiographs to optimize the diagnostic yield of the examination.     

Accuracy of enteroclysis in Crohn's disease of the small bowel: a retrospective study

The aim of this study was to evaluate the accuracy of enteroclysis in the diagnosis of Crohn's disease of the small bowel in a group of consecutive patients. From January 1992 to December 1995, 165 patients with suspected Crohn's disease of the small bowel presented to our institution for enteroclysis. In 14 patients up to three enteroclysis exams were performed. Most patients (78 %) underwent colonoscopy and retrograde ileoscopy. In the remaining patients clinical follow-up was used as gold standard. In 79 patients no radiographic abnormalities were found. Sixty-one patients (40 men and 21 women; mean age 34.2 years) had a radiological diagnosis of Crohn's disease. This involved the terminal ileum in 39 patients (64 %) either alone (n = 25) or in association with the pelvic ileum (n = 14). In 12 of these patients retrograde ileoscopy was not feasible. Twenty-one patients underwent surgery. In 4 patients pathology revealed diseases other than Crohn's. These patients had all ileocecal diseases (tuberculosis = 2; non-Hodgkin's lymphoma = 1; adenocarcinoma = 1). One false-negative result was observed. Overall, enteroclysis showed a sensitivity of 98.2 % and a positive predictive value of 93.4 %. Enteroclysis is a sensitive technique in evaluating both the extent and the severity of small bowel involvement in Crohn's disease, although the overlap of radiographic findings may hamper its accuracy when the disease is confined to the ileocecal area. Received: 25 November 1999; Revised: 4 April 2000; Accepted: 6 April 2000     

Enteroclysis and spiral CT examination in diagnosis and evaluation of small bowel Crohn's disease

INTRODUCTION: During the last few decades introducing many of new radiologic methods, diagnostic conditions and facilities of Crohn's disease has became markedly improved. Appropriate using of these technics definitely modifies the management of patients with known or suspected Crohn's disease serving reliable information about extent, severity and possible complications of disease. Enteroclysis and Computed tomography are the two major and basic methods to disclose or confirme diagnosis of Crohn's disease, obtain appropriate inforination about disease either with mucosal, transmural or extraintestinal manifestation. METHODS AND PATIENTS: We evaluated 281 patients who were referred in our institution under suspition of Crohn's disease. Enteroclysis and abdominal spiral CT in all cases were carried out usually within 1 week. The 172 patients underwent abdominal spiral CT as the primary examination to evaluate diagnostic value of spiral CT in this entity, while 109 patiens had enteroclysis followed by abdominal CT. In 11 cases we also perforined CT enteroclysis with administration of 0.5% methylcellulose solution thorough nasojejunal tube controlled by electric motor driven contrast pump. Results were compared with final clinical, pathological or surgical data were available. RESULTS: From the 281 patients eventually 74 proved Crohn's disease; sensitivity and specificity of enteroclysis proved to be 96 and 98%, while spiral CT sensitivity and specificity was 94 and 95%, respectively. Enteroclysis was superior to the spiral CT in demonstration of early lesions and functional disorders, while spiral CT proved to be essential in evaluation of transmural and extraintestinal complications. CONCLUSIONS: Regarding enteroclysis and spiral CT as complementary methods, they provide excellent results in diagnosis of Crohn's disease.     

Development of a new method for small bowel transit study

BACKGROUND AND PURPOSE: Currently, most studies combine the small bowel transit examination with gastric emptying time examination. There are significant drawbacks to this method. The radiotracer does not enter the small intestine in a bolus and the starting time for transit in the duodenum is difficult to define. This makes the result unreliable. In this study, we used a commercial enteric capsule containing radioactive charcoal to solve these problems. MATERIALS AND METHODS: Activated charcoal powder was mixed with Tc-99m pertechnetate and loaded to the enteric capsule which can resist gastric acid and dissolve only in the small intestine. In-vitro stability experiment was performed by immersing these capsules in a colorless phosphate buffer of variable pH which mimicked the condition in stomach and small intestine. In addition, ten healthy Chinese volunteers were included for in-vivo experiment. Anterior and posterior views of abdomen were obtained at regular 30-minute intervals until the eighth hour after administration of the radioactive enteric capsule. Small bowel transit time was calculated. RESULTS: The enteric capsule remained intact for at least 480 minutes in the solution mimicking gastric content (pH = 3.0) and disrupted at a mean duration of 227.2 minutes at a pH of 6.8 and at a mean duration of 212.4 minutes at a pH of 7.4 in the solution mimicking pancreaticobiliary secretions. In nine of ten volunteers, the small bowel transit time was between 30 to 270 minutes with a mean transit time of 140 min. In one volunteer, we failed to detect the exact time of small bowel transit because the capsule remained in the stomach throughout the study for up to 8 hours. CONCLUSIONS: We consider activated charcoal labeled with Tc-99m pertechnetate using an enteric capsule as the carrier to be a potential radioactive marker for small bowel transit study.     

CO2 as a distending medium for gastric and small bowel MRI: a feasibility study

This work evaluates carbon dioxide as a contrast medium for magnetic resonance imaging of the stomach and small bowel. Twelve healthy volunteers underwent rapid magnetic resonance imaging after oral administration of a carbon dioxide generating agent using a combination of breath-hold and interactive fluoroscopic imaging during breathing. Diagnostic-quality images were obtained in 100% of cases for the stomach and in 92, 75, 67 and 42% of cases for the duodenal segments 1–4, respectively. Visualisation of the jejunum and ileum proved unacceptable for clinical use and anti-peristaltic agents did not significantly influence the results. Further development of fast imaging and magnetic resonance interactive fluoroscopic methods may allow the use of carbon dioxide as a contrast medium for clinical imaging of the stomach and duodenum.     

Detailed per-oral small bowel examination vs. enteroclysis. Part I: Expenditures and radiation exposure

Time involved, patient reaction, and radiation exposure were compared for 25 patients undergoing a per-oral small bowel series and 18 having enteroclysis. For the per-oral study, mean room time was 17 minutes and fluoroscopy time was 4 minutes; for enteroclysis, mean room time was 44 minutes and fluoroscopy time was 22 minutes. Side effects were categorized as mild to moderate in two thirds of patients having enteroclysis, whereas they were minimal in 20% of those having the per-oral examination. Radiation exposure was five times greater for enteroclysis. These factors should be considered along with the age of the patient, indications for the examination, and the accuracy of the technique when planning a study of the small bowel.     

Magnetic Resonance in the study of the small bowel

Magnetic resonance (MR) of the small bowel is a field of application which for many years received little attention, being limited to advanced and selected research centres whose studies had no real clinical impact. Even after the first two publications in 1985, it was not until 1998 and the following years that a decisive improvement in scientific research articles was observed. This was largely due to the need for progressive development of adequate technologies, in particular fast imaging. Although the major technological problems have now been resolved, the optimisation of the study protocol is still under evaluation. In this regard there are two main methodological approaches: 1) "MR follow-through" following administration of an oral contrast medium; 2) "MR enteroclysis", following administration of contrast medium through a nasojejunal tube. Several contrast media are currently available for small bowel study, and they are classified according to signal intensity into positive, negative or biphasic. Biphasic agents are those most commonly used for both MR follow-through and MR enteroclysis. The major clinical indication for a study of the small bowel with MR is the evaluation of chronic inflammatory disease (Crohn's disease). Considerable experience has been obtained over the past years, with the consequent introduction of MR in routine clinical practice in many centres worldwide. Other potential clinical indications, at the moment to be considered work-in-progress, are the evaluation of malabsorption syndromes (and among them, celiac disease) and assessment of neoplastic diseases.     

Low b-value diffusion-weighted imaging for diagnosing strangulated small bowel obstruction: a feasibility study

Purpose:

To assess the feasibility of low b‐value diffusion‐weighted imaging (DWI) for diagnosing strangulated small bowel obstruction (SBO).

Materials and Methods:

Five volunteers and 14 patients with SBO underwent DWI at b‐values of 0 and 50 s/mm². Apparent diffusion coefficients (ADCs) and signal preservation ratios (SPRs) were measured in the distal jejunum in the volunteers before and after butylscopolamine administration, and in the (strangulated) closed loop, near the obstructive site, and far from the obstructive site in the patients. Low b‐value diffusion‐weighted images in the patients were quantitatively evaluated for diagnosing strangulation.

Results:

In the volunteers, mean ADC (10^?3 mm²/s) and SPR (%) before butylscopolamine administration (18.3 ± 5.9 and 41.4 ± 11.5) were significantly different (P < 0.05) from those after butylscopolamine administration (6.4 ± 3.6 and 73.7 ± 12.9). In the patients, mean ADCs and SPRs among the strangulated closed loop (3.8 ± 2.2 and 83.3 ± 9.3), near the obstructive site (12.1 ± 6.9 and 57.3 ± 18.5), and far from the obstructive site (26.8 ± 10.7 and 29.9 ± 16.4) were significantly different (P < 0.05). Areas under the receiver operating characteristic curve for the diagnosis of strangulation varied between 0.937 and 1.000.

Conclusion:

Low b‐value DWI is a feasible technique to distinguish the strangulated closed loop from nonstrangulated loops in SBO, and show promise for diagnosing strangulated SBO. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.

     

Early MRI findings of small bowel obstruction: an experimental study in rats

Purpose

This study was undertaken to identify the early magnetic resonance imaging (MRI) findings of small bowel obstruction (SBO) and to analyse their evolution over time comparing them with histological findings.

Materials and methods

SBO was surgically induced in 10 rats divided into two groups monitored at predetermined time points until the 8th hour: group 1, macroscopically observed and group 2, investigated with 7-Tesla micro-MRI (7T μ-MR). At the end of observation, the bowel was excised for histological analysis.

Results

7T μ-MRI T2-w sequences acquired 15 min after SBO, showed early evidence of bowel wall hyperintensity and a small amount of peritoneal free fluid. At 1 h, a hyperintensity of the loop proximal to the obstruction was found and, after 4 h, free fluid between the loops, bowel wall thickening and increased wall hyperintensity were also found. After 6 h hypotonic reflex ileus (only gas-filled dilated loops) was detected, which became paralytic ileus (dilation with air–fluid levels) after 8 h. The MRI findings were all confirmed at histological examination.

Conclusions

This study allows definition of the early MRI features of SBO (peritoneal free fluid and hyperintensity of the injured bowel) and their chronological evolution, also confirmed by histological examination. Our data suggest a potential role of MR imaging in the early diagnostic assessment and management of patients with SBO. The chance to achieve an early detection of bowel injury and to correlate the histological pattern with imaging findings could contribute to a finer and earlier diagnosis and a more effective treatment.