Small bowel radiography: how, when, and why?

Advances in heavy alkaline earth chemistry provide insight into complexation of weakly polarizing Ra2+, Ba2+, and Sr2+ cations

Numerous technologies-with catalytic, therapeutic, and diagnostic applications-would benefit from improved chelation strategies for heavy alkaline earth elements: Ra2+, Ba2+, and Sr2+. Unfortunately, chelating these metals is challenging because of their large size and weak polarizing power. We found 18-crown-6-tetracarboxylic acid (H4COCO) bound Ra2+, Ba2+, and Sr2+ to form M(HxCOCO)x-2. Upon isolating radioactive 223Ra from its parent radionuclides (227Ac and 227Th), 223Ra2+ reacted with the fully deprotonated COCO4- chelator to generate Ra(COCO)2-(aq) (log KRa(COCO)2- = 5.97 ± 0.01), a rare example of a molecular radium complex. Comparative analyses with Sr2+ and Ba2+ congeners informed on what attributes engendered success in heavy alkaline earth complexation. Chelators with high negative charge [-4 for Ra(COCO)2-(aq)] and many donor atoms [≥11 in Ra(COCO)2-(aq)] provided a framework for stable complex formation. These conditions achieved steric saturation and overcame the weak polarization powers associated with these large dicationic metals.

Malignant Small Bowel Neoplasms:a review of post-contrast multiphasic multidetector computed tomography

Small bowel neoplasms are rare and account for 3-6% of all gastrointestinal neoplasms. For the diagnosis of small bowel neoplasms, differentiating normal bowel tissue from tumor is critical and depends on imaging modality and scanning techniques. The detection and characterization of small bowel neoplasms have recently improved with the advance of computed tomography (CT) technology. Post-contrast multiphasic CT is an aid to detection and recognition of the vascular nature of small bowel neoplasms. Understanding the typical post-contrast multiphasic CT features of small bowel neoplasms is important because of overlapping features and the necessity of evaluating associated complications and metastases to lymph node and other organs. However, accurate classification of pathologies is still challenging in clinical practice. Texture analysis can quantify complex mathematical patterns within the gray-level distribution of the pixels and voxels of digital images, and texture analysis of the post-contrast multidetector CT data of various tumors has been attracting attention in recent years. The aim of this article is to provide a comprehensive guide to the relevant imaging features for different types of malignant small bowel neoplasms. J. Med. Invest. 69 : 19-24, February, 2022.

Small Bowel Neoplasms: A Pictorial Review

Small bowel tumors are rare and account for approximately 3% of all gastrointestinal tumors in the United States. The incidence of small bowel neoplasms is rising-in particular, there is a rising incidence of small bowel carcinoid tumors. This may in part be due to small bowel lesion identification in an increasing number of cross-sectional imaging studies performed for other indications as well as increased use of advanced imaging techniques to assess specifically for small bowel disease. Diagnosis is a challenge owing to nonspecific clinical manifestation, rare occurrence, and low index of clinical suspicion. Yet, various small bowel neoplasms have characteristic imaging features at CT and MRI when optimal distention of the small bowel is achieved, correlating well with features seen in gross specimens. Understanding the imaging features of small bowel neoplasms is important to improve the radiologist's ability to diagnose and characterize small bowel neoplasms. Most small bowel tumors are clinically silent for long periods, and nearly half of the benign tumors are found incidentally during surgery or at cross-sectional imaging performed for other reasons. The authors review the imaging features of common benign and malignant small bowel neoplasms to aid the radiologist in diagnosis of small bowel tumors. ^©RSNA, 2020.

Accuracy of Plain Abdominal Radiography in the Differentiation between Small Bowel Obstruction and Small Bowel Ileus in Acute Abdomen Presenting to Emergency Department

Introduction

Our purpose was to evaluate whether plain abdominal radiography (PAR) could accurately differentiate between small bowel obstruction (SBO) and small bowel ileus (SBI) in an emergency setting. We also evaluated the value of known classic signs on the PAR for differentiating between SBO and SBI.

Methods

This retrospective study included 216 emergency room patients who had small bowel distension (maximal small bowel diameter ≥2.5 cm) on the PAR and who underwent successive abdominal computed tomography. One radiologist and one emergency physician retrospectively reviewed PAR in consensus, unaware of the patients' clinical data; they divided the patients into an SBO group and an SBI group according to the radiographic findings. Presence or numeric values of 10 radiographic signs were also recorded. Final diagnoses of SBO and SBI were established by a combined analysis of medical charts, surgical records, radiographic findings on abdominal computed tomography, and small bowel studies. The differential diagnoses based on PAR and the final diagnoses were compared, and the sensitivity and specificity of PAR were calculated. We also evaluated the differences among 10 radiographic signs between the final SBO and SBI groups.

Results

Sensitivity and specificity of PAR for SBO were 82.0% and 92.4%, respectively. Among the 10 radiographic signs, all except maximal colon diameter were statistically significant predictors on the final diagnosis.

Conclusions

PAR is an accurate and effective initial imaging modality for differentiating between SBO and SBI in an emergency setting, and most of the classic radiographic signs have a diagnostic value.

Small bowel tuberculosis by multidetector CT enteroclysis

PURPOSE

To prospectively evaluate the role of multidetector computed tomography (CT) enteroclysis in evaluation and diagnostic characterization of suspected small bowel tuberculosis.

MATERIALS AND METHODS

The study group included 21 human subjects suspected of having small bowel tuberculosis. A nasoenteric tube was positioned into the duodenojejunal junction under fluoroscopic guidance and water was infused by hand injection. After intravenous administration of 120 mL of iodinated contrast material, multidetector CT enteroclysis images were obtained with 40 × 0.625 mm collimation and findings were analyzed by three readers working in consensus. Findings were compared with the results of endoscopy, histopathological analysis, and clinical follow up.

RESULTS

Multidetector CT enteroclysis was well tolerated in 20 patients; one of the patients complained of vomiting during intubation. Using multidetector CT enteroclysis diagnosis of abdominal tuberculosis was made in sixteen patients, out of which small bowel involvement was seen in 13 patients. Multidetector CT enteroclysis demonstrated Crohn's disease in one patients and normal in four patients. The sensitivity and specificity in diagnosing abdominal tuberculosis by CT enteroclysis came out to be 93.75 and 100 % respectively.

CONCLUSIONS

Multidetector CT enteroclysis is well tolerable and accurate modality for evaluation and diagnostic characterization of small bowel tuberculosis.

Noninvasive imaging of the small bowel in Crohn's disease: the final frontier

The substantial morbidity and mortality associated with Crohn's disease underlines the importance of accurate assessment at presentation, during follow-up, when investigating complications, and when evaluating the response to therapeutic interventions. Accurate methods are required to quantify the severity and extent of disease.

Small bowel obstruction: the art of management

Strategies for the management of small bowel obstructions have changed significantly over the years. Nonoperative medical management has become the mainstay of treatment of many small bowel obstructions. However, the key to the management of small bowel obstructions is identifying those patients who need surgical intervention. Identification of those at risk for bowel ischemia and bowel death is an art as much as it is a science. Using the current literature and the past knowledge regarding small bowel obstructions, the clinician must carefully identify the signs and symptoms that suggest the need for operative intervention. Classification of the obstruction, history and physical examination, imaging, response to decompression and resuscitation, and resolution or progression of symptoms are the key factors influencing the management of small bowel obstructions.

MR motility imaging in Crohn's disease improves lesion detection compared with standard MR imaging

OBJECTIVE

To evaluate retrospectively in patients with Crohn's disease (CD) if magnetic resonance (MR) motility alterations correlate with CD typical lesions leading to an increased detection rate.

METHODS

Forty patients with histologically proven CD underwent MR enterography (MRE), including coronal cine sequences (cine MRE), in addition to the standard CD MR protocol. Two blinded readings were performed with and without cine MRE. Locations presenting motility alterations on the cine sequences were analysed on standard MRE for CD-related lesions. This was compared with a second reading using the standard clinical MRE protocol alone.

RESULTS

The number of lesions localised by cine MRE and identified on standard MRE compared with standard MRE alone were 35/24 for wall thickening (p = 0.002), 24/20 for stenoses (p = 0.05), 17/11 for wall layering (p = 0.02), 5/3 for mucosal ulcers (p = 0.02) and 21/17 for the comb sign (p = 0.05). Overall, cine MRE detected 35 more CD-specific findings than standard MRE alone (124/89; p = 0.007) and significantly more patients with CD-relevant MR findings (34/28; p = 0.03).

CONCLUSION

CD lesions seem to be associated with motility changes and this leads to an increased lesion detection rate compared with standard-MRE imaging alone.

CT enteroclysis in incomplete small bowel obstruction

The timing of surgical intervention as well as the optimal method of radiologic investigation for patients with incomplete, open loop small bowel obstruction has changed over the past two decades. This review focuses on the role of computed tomographic enteroclysis in the evaluation of patients with suspected small bowel obstruction. The technique of examination is described and an overview of its clinical applications and imaging controversy are presented.

Abdominopelvic extra-enteric findings at computed tomography enteroclysis: a retrospective evaluation of 430 consecutive patients

BACKGROUND

Our objective was to retrospectively determine the frequency with which CT enteroclysis (CTE) shows abdominopelvic extra-enteric abnormalities and to analyze how such findings had actually and prospectively affected patient's care.

METHODS

The CTE examinations of 430 consecutive patients were retrospectively and blindly reviewed for the presence of possible pathologic conditions that might have affected abdominopelvic organs other than the small bowel. Extra-enteric abnormalities were categorized as negligible or important and correlated with patient's outcome and thus classified as having or not influenced patient's care.

RESULTS

Abdominopelvic extra-enteric abnormalities were present on CTE in 258 (60%) of 430 patients. Retrospective analysis of CTE images revealed negligible abnormalities in 217 patients (217/430, 50.5%) and important ones in 41 patients (41/430, 9.5%). Among the 41 patients with important abnormalities, CTE demonstrated already documented abnormalities in 22 patients (22/41, 53.7%) and unknown abnormalities in 19 patients (19/41, 46.3%). In the latter 19 patients, the detection of unknown abnormalities altered patient's care in 18 (94.7%) of them. In one patient (1/19, 5.3%), important abnormality was detected during retrospective evaluation but not prospectively, resulting in a delayed treatment, yielding missed important abnormality rate of 2.4% (1/41).

CONCLUSIONS

Abdominopelvic extra-enteric abnormalities are frequent on CTE, but their depictions rarely alter patient's care. However, in a few patients (19/430; 4.4%), CTE may reveal unknown extra-enteric abnormalities that require further evaluation and have substantial impact on patient's management.

Enteroscopy and its relationship to radiological small bowel imaging

The field of radiological small bowel imaging is changing rapidly, as is small bowel enteroscopy. New techniques allow the depiction of intraluminal, mural, and extraintestinal features of various small bowel disorders, such as Crohn disease, small bowel polyposis syndromes, small intestinal malignancies, and celiac disease. For patients requiring repeated small bowel imaging, modalities that do not use ionizing radiation, such as ultrasound or magnetic resonance imaging, should be considered.

CT enteroclysis in small bowel Crohn's disease

The diagnostic evaluation of small bowel Crohn's disease has changed dramatically over the last decade. The introduction of wireless capsule endoscopy, double balloon endoscopy and the introduction of newer therapeutic agents have changed the role of imaging in the small bowel. Additionally, advances in multidetector CT technology have further changed how radiologic investigations are utilized in the diagnosis and management of small bowel Crohn's disease. This article describes how we perform CT enteroclysis in the investigation of small bowel Crohn's disease and discusses the role of CT enteroclysis in the current management of small bowel Crohn's disease.

Computed tomography enteroclysis in the diagnosis of intestinal diseases

The role of computed tomography (CT) enteroclysis in the imaging of small bowel diseases is expanded with recent technological advances in multidetector CT system. Computed tomography enteroclysis is the examination of choice for patients with symptoms of intermittent small bowel obstruction, especially when there is a history of prior complex abdominal surgery, abdominal tumor, radiation therapy, and also in high grade obstructions with suspicion of extraintestinal internal fistula. Computed tomography enteroclysis is becoming the first-line modality for the evaluation of advanced and complicated small bowel Crohn disease. Computed tomography enteroclysis can also become an important complementary imaging technique to capsule endoscopy in the assessment of small bowel neoplasms and occult gastrointestinal hemorrhage. In this study, the technique and clinical applications of CT enteroclysis are reviewed; its advantages and limitations compared with the other imaging techniques and capsule endoscopy are discussed.

Small-bowel obstruction: state-of-the-art imaging and its role in clinical management

Small-bowel obstruction (SBO) is a common clinical condition with signs and symptoms similar to other acute abdominal disorders. The radiologic investigation of patients with SBO as well as the indications and timing of surgical intervention have changed over the past 2 decades. This review focuses on modern imaging techniques and their role in both the diagnosis and treatment of patients with SBO.

MRI of the small bowel with oral contrast or nasojejunal intubation in Crohn's disease: randomized comparison of patient acceptance

OBJECTIVE

Magnetic resonance imaging of the small bowel with an oral contrast (MRI per os) is believed to generate fewer adverse symptoms compared with installation of the contrast in a nasojejunal catheter (MRE). However, there is very little evidence to support this assumption. The aim of this study was to evaluate the compliance of patients examined with both of these MRI methods.

MATERIAL AND METHODS

Patients with suspected or known Crohn's disease referred for MRI of the small bowel underwent both MRI per os and MRE within 7 days. A questionnaire was answered immediately and 24 h after the procedure. Adverse symptoms were graded on a visual analogue scale (VAS). Responses were compared with paired and independent sample t-tests and signed-rank tests. Correlation of each symptom to the overall discomfort was evaluated with Spearman's correlation coefficient.

RESULTS

Thirty-eight patients (18 F, 20 M) were included in the analysis. Abdominal pain and discomfort were lower with MRI per os than with MRE (mean VAS pain score immediately after: 10 mm and 33 mm, respectively, p < 0.001; mean VAS discomfort score 24 h after: 18 mm and 62 mm, respectively, p < 0.001). Nausea and abdominal pain were correlated with overall discomfort after MRI per os (r = 0.56 for both, p < 0.001). No symptoms were significantly correlated with discomfort experienced with MRE. More patients accepted repeat MRI per os examination (n = 36) than MRE (n = 22, p = 0.001).

CONCLUSION

Patients preferred and experienced less abdominal pain and discomfort with MRI per os than with MRE.

Internal fistulas in Crohn disease: magnetic resonance enteroclysis

Internal fistulas (IFs) and abscesses are the most common complications of Crohn disease (CD). To reliably diagnose and clearly distinguish inflammatory or fibrostenotic manifestations of CD from its complications is of paramount importance to appropriately guide therapeutic decisions. Magnetic resonance enteroclysis (MRE), a recently introduced technique for small bowel imaging, has proved a high efficacy in the depiction of luminal and extraluminal manifestations of CD and holds great promise as a powerful diagnostic tool in the comprehensive diagnostic workup of this disease. As of yet, the characteristic imaging appearance of IFs on MRE has not been described in detail. This article reviews the performance of conventional imaging techniques and the current potential of MRE in the depiction of IFs in CD. Typical imaging morphology and characteristic imaging findings of IFs on MRE are described in detail and a newly defined and highly indicative imaging finding, the "star-sign," is presented and discussed.

Capsule enteroscopy and radiology of the small intestine

In a very few years, the video capsule for small bowel enteroscopy has gained widespread clinical acceptance. It is readily ingested, disposable, and allows for a complete, low-invasive endoscopic examination of the entire mucosa of the small bowel. It is a patient-friendly method and a first-line procedure in the difficult evaluation of obscure gastrointestinal bleeding. It has the highest proven figure of diagnostic sensitivity for detecting lesions of the mucosa, irrespective of aetiology. The limitations of capsule endoscopy include difficulty in localising mucosal lesions anatomically and its restricted use in patients with dysphagia, strictures or motor dysfunction. Strictures, transmural and extra-mural lesions in patients with small bowel Crohn's disease are evaluated by MRI- enterography and CT-enterography.

CT enteroclysis: techniques and applications

CT enteroclysis overcomes the individual deficiencies of both barium enteroclysis and conventional CT and combines the advantages of both into one technique whose clinical applicability has been simplified and made more reliable with multidetector CT technology. This article examines the techniques of CT enteroclysis and presents an overview of its clinical applications relative to other methods of small bowel imaging.

Video capsule endoscopy in patients with known or suspected small bowel stricture previously tested with the dissolving patency capsule

GOALS

To assess the safety of the Pillcam in patients with known or suspected radiologic stricture, previously tested for small bowel patency using the Given Patency capsule.

BACKGROUND

Intestinal stricture contributes a major contraindication to video capsule endoscopy (VCE), because of the risk of capsule retention.

STUDY

Twenty-seven patients (16 female, mean age 44.2 y) with known or suspected intestinal stricture were enrolled prospectively. Twenty-four had Crohn's disease, 2 had adhesive syndrome and 1 had a suspected ischemic stricture. Patients underwent the Patency capsule test. In patients in whom the Patency capsule was excreted intact within 72 hours postingestion without occurrence of any adverse event, VCE was performed to assess the presence of strictures or other gastrointestinal pathologies. The following parameters were evaluated: transit time of Patency capsules and/or tags from ingestion to excretion, condition of the Patency capsule at excretion, transit time of the Pillcam capsule, the ability of Pillcam capsule to detect intestinal strictures and small bowel pathologies, any adverse events.

RESULTS

Twenty-five patients (92.6%) retrieved the Patency capsule in the stools. Six patients complained of abdominal pain, 4 of whom excreted a nonintact capsule. Hospitalization was required in 1 (4.3%) patient with Crohn's disease due to occlusive syndrome. Fifteen patients (65.3%) excreted an intact Patency capsule after a mean transit time of 25.6 hours without any adverse events. These 15 patients underwent the VCE successfully.

CONCLUSIONS

Passage of an intact Patency capsule across a small bowel stricture provides direct evidence of functional patency of the gut lumen and allows a safe VCE. Intestinal strictures should not be considered an absolute contraindication for VCE.

[Diagnostic imaging of the small bowel]

This article describes the different imaging techniques used in the study of the small bowel. We define the technical requirements that conventional small bowel follow through studies must fulfill to be considered an efficacious examination (individualized study of each bowel loop by compression and fluoroscopy); we evaluate the different types of enteroclysis, giving special attention to the biphasic type, which is the most commonly employed; we discuss the advantages and disadvantages of biphasic enteroclysis with respect to conventional small bowel follow through studies; and finally we evaluate the role of modern techniques of image acquisition, tomodensitometry and magnetic resonance imaging used together with traditional techniques. Small bowel studies require accurate indications for radiologic study, thorough and meticulous examination, and careful interpretation of the images obtained. Although the modern techniques of magnetic resonance and computed tomography enteroclysis are no better than conventional small bowel follow through or enteroclysis at demonstrating the details of the intestinal mucosa, they are of great use in solving the problem of the superimposition of intestinal loops and provide information about the intestinal wall and possible extraluminal pathology.

Multislice CT enteroclysis: technique and clinical applications

Computed tomography (CT) enteroclysis was introduced to overcome the individual deficiencies of barium enteroclysis and abdominal CT. The use of multislice CT technology has made the procedure a feasible extension of the intubation infusion method of small bowel examination. This review is an update of the technique and clinical application of CT enteroclysis with illustrations.

Sonoenteroclysis: a new technique for the diagnosis of small bowel diseases

BACKGROUND

Radiologic evaluation of small bowel is usually done by barium examination, which involves considerable radiation exposure. A new sonographic method, sonoenteroclysis, is a promising technique for diagnosing small intestinal disorders. In this study the applicability, performance, and diagnostic yield of sonoenteroclysis were assessed and the results of this novel method were compared with those of barium enteroclysis.

METHODS

Forty-five consecutive patients with suspected small bowel disorder were studied. All patients underwent abdominal ultrasound before and after infusion of an isotonic nonabsorbable electrolyte solution containing polyethylene glycol through a nasojejunal tube (modified Billbao Dotter tube), and images at various levels were obtained. Small bowel wall thickness, luminal narrowing, intestinal dilatation, peristalsis, and extraintestinal complications were noted. It was followed by barium enteroclysis and findings were recorded. Findings of sonoenteroclysis were compared with those of barium enteroclysis.

RESULTS

Satisfactory distention of the intestinal lumen was obtained with sequential visualization of jejunoileal loops in 34.4 +/- 18.4 min. Of 45 patients, 10 showed normal small bowel on sonoenteroclysis and barium enteroclysis. These 10 patients served as controls. Sonoenteroclysis displayed normal diameters smaller than 3.0 and 2.0 cm for the jejunum and ileum, respectively. Bowel wall thickness was 1.7 to 3.0 mm and all five layers of bowel wall could be well appreciated. Valvulae conniventes were clearly visualized with a fold thickness between 1.4 and 2.0 mm. The remaining 35 patients showed abnormalities in the form of strictures, matted bowel loops, dilated loops, thickened folds, deformed ileocecal junction, mass lesions, etc., on sonoenteroclysis and barium enteroclysis. In addition, sonoenteroclysis showed thickened bowel wall with loss of stratification. Extraintestinal findings such as enlarged lymph nodes and ascites were also disclosed at the time of sonography. These were diagnosed subsequently as cases of tuberculosis (n = 23), celiac disease (n = 6), adenocarcinoma (n = 2), leiomyoma (n = 2), Immunoproliferative small intestinal disease (n = 1), and segmental enteritis (n = 1).

CONCLUSIONS

The diagnostic accuracy of sonoenteroclysis for detecting small bowel lesions is comparable to that of barium enteroclysis. This new, widely available, inexpensive, and undemanding technique can be used as an initial investigation in the evaluation of patients with small bowel disorders.

Multidetector row CT of the small bowel

Multidetector row CT (MDCT) has become an imaging technique of choice to study routinely the small bowel. Thin collimation and fast scanning allow coverage of the entire abdomen within a single suspended respiration phase allowing the use of multiple enhancement phases after intravenous contrast administration. MDCT of the small bowel can identify and stage most of the common diseases of the small bowel. MDCT is changing the paradigm for diagnosing small bowel disease by becoming the first diagnostic line for almost all small bowel diseases. MDCT has the needed sensitivity and specificity, the availability, and the safety for a front-line diagnostic method.

CT enteroclysis: technique and clinical applications

CT enteroclysis (CTE) has been gradually evolving with technical developments of spiral and multidetector row CT technology. It has nowadays become a well-defined imaging modality for the evaluation of various small bowel disorders. Volume challenge of 2L of enteral contrast agent administrated to the small bowel via a nasojejunal catheter ensures luminal distension, the prerequisite for the detection of mural abnormalities, also facilitating the accurate visualization of intraluminal lesions. CT acquisition is centered on small bowel loops, reconstructed in thin axial slices and completed by multiplanar views. Image analysis is essentially done in cine-mode on work-stations. CTE is of particular diagnostic value in intermediate or advanced stages of Cohn's disease, including the depiction of extraintestinal complications. It has become the imaging modality of choice for the localization and characterization of small bowel tumors. The cause and degree of low-grade small bowel obstruction is more readily analyzed with the technique of CTE than conventional CT. Limitations of CTE concern the assessment of pure intestinal motility disorders, superficial mucosal lesions and arteriovenous malformations of the small bowel, which are not consistently visualized. CTE should be selectively used to answer specific questions of the small bowel. It essentially contributes to the diagnostic quality of modern small bowel imaging, and therefore deserves an established, well-defined place among the other available techniques.

Multi-detector CT enterography with iso-osmotic mannitol as oral contrast for detecting small bowel disease

AIM: To assess the feasibility and usefulness of multi-detector CT enterography with orally administered iso-osmotic mannitol as negative contrast in demonstrating small bowel disease.

METHODS: Thirteen volunteers and 38 patients with various kinds of small bowel disease were examined. We administered about 1500 mL iso-osmotic mannitol as negative contrast agent and then proceeded with helical CT scanning on a Siemens Sensation 16 scanner. All volunteers and patients were interviewed about their tolerance of the procedure. Two radiologists post-processed imaging data with MPR, thin MIP, VRT and INSPACE when necessary and then interpreted the scans, and adequacy of luminal distention was evaluated on a four-point scale. Demonstration of features of various kinds of small bowel disease was analyzed.

RESULTS: The taste of iso-osmotic mannitol is good (slightly sweet) and acceptable by all. Small bowel distention was excellent and moderate in most volunteers and patients. CT features of many kinds of diseases such as tumors, Crohn’s disease,and small bowel obstruction, etc. were clearly displayed.

CONCLUSION: Multi-detector CT enterography with iso-osmotic mannitol as negative contrast to distend the small bowel is a simple, rapid, noninvasive and effective method of evaluating small bowel disease.

A retrospective review of enteroclysis in patients with obscure gastrointestinal bleeding and chronic abdominal pain of undetermined etiology

Our purpose was to determine the diagnostic utility of enteroclysis in the evaluation of obscure gastrointestinal bleeding and abdominal pain of unknown etiology. This is a retrospective review of 97 consecutive patients (mean age, 54.1+/-17.5 [SD] years; 49 male and 48 female) who underwent enteroclysis at Temple University Hospital from January 1994 to October 2001 for the evaluation of obscure GI bleeding or chronic abdominal pain of undetermined etiology. Prior to enteroclysis all patients had an EGD and colonoscopy, which were nondiagnostic for their symptoms. Sixty-three patients (64.9%) had enteroscopy performed prior to enteroclysis that was also negative. Enteroclysis results were defined as positive based on anatomical or functional abnormalities. Analysis of the data included the percentage yield of positive exams, the percentage of positive results per symptom category, and the percentage of patients with a change in clinical management based on positive enteroclysis results. Ninety-seven patients underwent enteroclysis. The indications for enteroclysis were obscure GI bleeding in 67 patients (69.1%) and chronic abdominal pain in 30 patients (30.9%). The number of positive exams was 19 (19.6%). Fourteen of the 67 patients with the indication of GI bleeding had a positive exam (21%), while 5 of the 30 patients with chronic abdominal pain had a positive result (16.7%). There was a change in clinical management due to the enteroclysis results in 10 patients: 7 patients with GI bleeding (10%) and 3 patients with chronic abdominal pain (10%). Positive enteroclysis findings included adhesions (7), filling defects and masses (5), strictures (2), small bowel diverticulosis (1), mucosal abnormalities (3), and a motility disorder (1). The overall positive yield for enteroclysis was 19.6%, with a yield of 16.7% for chronic abdominal pain and 21% for gastrointestinal bleeding. Enteroclysis results changed the clinical management in approximately 10% of the patients.

Capsule endoscopy vs. push enteroscopy and enteroclysis in suspected small-bowel Crohn's disease

BACKGROUND

The diagnosis of small-bowel Crohn's disease sometimes is difficult and may be missed by conventional imaging studies. Capsule endoscopy might identify small-bowel disease undetected by other investigations.

METHODS

Patients with or without known Crohn's disease who were suspected to have small-bowel Crohn's disease were prospectively evaluated with push enteroscopy, enteroclysis, and capsule endoscopy. Each examiner was blinded to results of other investigations. Referring doctors were required to complete questionnaires before and after the investigations.

RESULTS

Twenty-two patients were known to have Crohn's disease (Group 1), and 21 were suspected to have small-bowel Crohn's disease (Group 2). In Group 1, capsule endoscopy detected more erosions than the other two investigations (p < 0.001). In Group 2, a new diagnosis of Crohn's disease was made in two patients, but there was no significant difference in yield compared with the other two investigations. Referring physicians rated the usefulness of capsule endoscopy as 4.4 on a scale of 5. Capsule endoscopy changed management for 30 patients (70%).

CONCLUSIONS

Capsule endoscopy has a higher yield than push enteroscopy and enteroclysis in patients with known Crohn's disease when small-bowel mucosal disease is suspected, and this leads to a change in management in the majority of these patients.

Radiology of small bowel obstruction: contemporary approach and controversies

The radiologic workup of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this complex situation have undergone considerable changes over the past two decades. The diagnosis and treatment of small bowel obstruction, a common clinical condition often associated with signs and symptoms similar to those seen in other acute abdominal disorders, continue to evolve. This article examines the changes related to the use of imaging in the diagnosis and management of patients with this potentially dangerous problem and revisits pertinent controversies.

Small-bowel diseases: prospective evaluation of multi-detector row helical CT enteroclysis in 107 consecutive patients

PURPOSE

To prospectively evaluate multi-detector row helical computed tomographic (CT) enteroclysis for the depiction of small-bowel diseases.

MATERIALS AND METHODS

The study group included 107 patients who were suspected of having small-bowel tumor (n = 8), active inflammatory small-bowel disease (n = 18), unexplained gastrointestinal bleeding (n = 36), refractory celiac sprue (n = 14), and low-grade small-bowel obstruction (n = 31). A nasoenteric tube was positioned into the duodenojejunal junction by using fluoroscopic guidance and water was infused with a pressure-controlled pump. After intravenous administration of 120 mL of iodinated contrast material, multi-detector row helical CT enteroclysis images were obtained with 4 x 2.5 mm collimation (four detector rows and 2.5-mm section thickness). Multi-detector row helical CT enteroclysis findings were analyzed by two readers working in consensus. Findings were compared with the results of endoscopy, enteroscopy, videocapsule endoscopy, histopathologic analysis, or clinical follow-up.

RESULTS

Multi-detector row helical CT enteroclysis was well tolerated in 106 patients; one patient complained of abdominal pain after the examination. Multi-detector row helical CT enteroclysis allowed the diagnosis of small-bowel masses (n = 21), active Crohn disease (n = 9), small-bowel tuberculosis (n = 2), small-bowel lymphoma complicating celiac disease (n = 4), and confirmed low-grade small-bowel obstruction (n = 12). Multi-detector row helical CT enteroclysis demonstrated normal findings in 60 patients. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of multi-detector row helical CT enteroclysis were 100%, 95%, 97%, 94%, and 100%, respectively.

CONCLUSION

Multi-detector row helical CT enteroclysis allows depiction of small-bowel diseases in patients suspected of having small-bowel conditions.

Combined small and large bowel MR imaging in patients with Crohn's disease: a feasibility study

MRI of the small bowel is a new method for the assessment of inflammatory bowel diseases. However, inflammatory bowel disease can affect both the small and large bowel. Therefore, our goal was to assess the feasibility of displaying the small bowel and colon simultaneously by MR imaging. Eighteen patients with inflammatory bowel disease were studied. For small bowel distension, patients ingested a solution containing mannitol and locust bean gum. Furthermore, the colon was rectally filled with water. MR examinations were performed on a 1.5-T system. Before and after intravenous gadolinium administration, a T1w data set was collected. All patients underwent conventional colonoscopy as a standard of reference. The oral ingestion and the rectal application of water allowed an assessment of the small bowel and colon in all patients. By means of MRI (endoscopy), 19 (13) inflamed bowel segments in the colon and terminal ileum were detected. Furthermore, eight additional inflammatory lesions in the jejunum and proximal ileum that had not been endoscopically accessible were found by MRI. The simultaneous display of the small and large bowel by MRI is feasible. Major advantages of the proposed MR concept are related to its non-invasive character as well as to the potential to visualize parts of the small bowel that cannot be reached by endoscopy.

Análise retrospectiva do trânsito do delgado em um serviço de radiologia de hospital geral

OBJETIVO: Os autores se propõem a revisar os exames de trânsito do delgado, a fim de demonstrar os principais diagnósticos e achados radiológicos, e o atual benefício para o paciente. MATERIAIS E MÉTODOS: Estudo retrospectivo e descritivo realizado a partir de levantamento de exames realizados no período de janeiro/2001 a junho/2002, no serviço de radiologia do Hospital Santa Cruz da Beneficência Portuguesa de Niterói. RESULTADOS: Do total de 60 exames, 24 (40,0%) apresentaram alterações radiológicas (anatômicas, enterites, divertículos, relacionadas a cirurgias e outras) e 36 (60,0%) foram normais. Observamos que 36 pacientes (60,0%) tinham entre 35 e 65 anos incompletos, apenas dois (3,32%) eram menores de 18 anos e o paciente mais idoso tinha 87 anos. CONCLUSÃO: Apesar do advento da endoscopia para a avaliação do trato gastrintestinal superior e inferior, o uso do estudo contrastado do intestino delgado se manteve como método de escolha para avaliação do duodeno, jejuno e íleo. Sabe-se que o trânsito do delgado é a principal técnica diagnóstica para o estudo deste órgão e importante para o estudo das enterites, além de ser um exame de fácil execução e de alta sensibilidade. Dessa forma, estamos reforçando a sua importância diagnóstica e devemos ter em mente que o exame do trato gastrintestinal superior é complementar, devendo considerar suas limitações e vantagens.

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.

Strictures from Crohn's disease diagnosed by video capsule endoscopy

Video capsule endoscopy is a new diagnostic modality that allows imaging of the entire small intestine. We report on a patient with a presumed but undocumented case of Crohn's disease who was found to have 9 ileal strictures by video capsule endoscopy. These strictures were undetected by small intestinal contrast studies and required surgical intervention. This case report suggests that small bowel radiographic studies may not be as sensitive for the detection of clinically significant luminal lesions as once thought.

Current concepts in imaging of small bowel obstruction

The diagnosis and treatment of small bowel obstruction continue to evolve. The imaging approach in the work-up of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this disease have undergone considerable changes over the past two decades. This article examines the current concepts related to the use of imaging technology in the diagnosis and management of patients with small bowel obstruction. The meaning of frequently used but poorly defined terms in describing intestinal obstruction is clarified and illustrated.

Technical refinements in enteroclysis

As the primary method of investigating the small bowel, enteroclysis remains a technique in evolution. Technical refinements have made the examination faster to perform, better tolerated by patients, and easier to interpret. More recently, its essential principle of volume challenge has been combined with the tremendous advantage of CT cross-sectional imaging with multiplanar reformatting to give rise to the exciting new techniques of CT enteroclysis and MR enteroclysis (see separate reviews in this issue). Through improvements in methodology and advancements in technology, the future of enteroclysis looks bright indeed.

Multidetector-row helical CT enteroclysis

Currently, CT-E is not recommended as the first-line examination in patients when mucosal detail is required. Double-contrast barium air enteroclysis has advantages in demonstrating small mucosal abnormalities. The authors find CT-E of value in the work-up of patients with symptoms of intermittent small bowel obstruction, particularly those with a history of prior abdominal surgery; in the further work-up of selected patients with high-grade obstruction in whom general surgeons prefer initial conservative management (immediate postoperative small bowel obstruction, patients with history of prior abdominal surgery for malignant tumor, history of radiation treatment, and possible internal extraintestinal fistulae); in looking for complications of small bowel Crohn's disease; and in the patient with unexplained anemia or gastrointestinal bleeding. In a series of patients who had both abdominal CT and barium enteroclysis done, each examination provided unique and complimentary diagnostic information. Because CT-E combines the advantages of both methods of examination, is it the optimum imaging work-up in the investigation of small bowel disease? Further research and clinical experience will define the precise role of CT-E in the investigation of small bowel disease. Experience with this method of examination is limited to a few institutions, performed by investigators with interest in small bowel diseases. The addition of cross-sectional display and multiplanar reformatting made possible by multidetector-row helical CT to enteral volume change and the use of multifunctional nasointestinal catheters make CT-E an important tool in the investigation of small bowel disease. Experience has shown the increased reliability of any method of examining the small bowel that challenges intestinal wall distensibility by fluid enteral volume infusion.

Meckel's diverticulum mimicking infantile colic: sonographic detection

We report a case of Meckel's diverticulum in a 6-month-old girl who presented with a 5-month history of chronic screaming but no symptoms or signs of intestinal obstruction. Infantile colic was the presumptive diagnosis. Abdominal sonography at 6 months of age demonstrated an abdominal mass with an anechoic center and a double-layered wall, surrounded by bowel loops. Abdominal CT and barium enema x-ray studies demonstrated nonspecific findings of a cystic mass with compression of adjacent bowel loops. Histologic examination of the resected mass revealed a Meckel's diverticulum with a perforation sealed off by the neighboring bowel and mesentery to form an inflammatory mass.

Detection of unsuspected colonic abnormalities using the pneumocolon technique during small bowel meal examination

AIMS

The pneumocolon technique in small bowel meal examination is used to obtain double-contrast views of the distal ileum. The purpose of this study was to determine the proportion of cases in which an overhead pneumocolon radiograph demonstrated clinically relevant findings in the colon.

METHODS

The overhead pneumocolon radiographs in 151 patients who underwent small bowel meals were evaluated retrospectively. A chart review was performed on those patients with positive colonic findings to determine if the suspected abnormalities affected patient management.

RESULTS

Colonic abnormalities were identified in 34 of the 151 patients. One patient had a previously undiagnosed ascending colonic cancer; 17 had evidence of acute or chronic colitis; 13 had diverticulosis; one had a caecal polyp; one had an ileosigmoid fistula; one had a filling defect in the ascending colon. In 25 cases the colonic abnormality was visible only on the pneumocolon radiograph and not on the preceding single-contrast images. Management was altered by the colonic findings in seven cases. False-positive findings occurred in two cases.

CONCLUSIONS

A routine overhead radiograph following use of the pneumocolon technique is a useful adjunct to small bowel meal examination as it can yield unsuspected and clinically significant colonic findings.Chou, S. (2000). Clinical Radiology55, 459-464.

Adult celiac disease: US signs

PURPOSE

To examine whether distinct ultrasonographic (US) signs exist in patients with adult celiac disease.

MATERIALS AND METHODS

In a partly retrospective study, abdominal sonograms were obtained in 11 patients with adult celiac disease. Fifty matched control subjects also were examined. After the patients had fasted overnight, they were examined with 2-4-MHz abdominal and high-frequency 5-10-MHz linear-array US transducers.

RESULTS

The authors found several US pathologic signs in patients with untreated disease, including abnormal fluid-filled small intestine in all 11 patients, flaccid and moderately dilated small-bowel loops (2.5-3.5 cm) in eight, slight diffuse thickening of the small-bowel wall (3-5 mm) in seven, increased peristalsis of the small intestine in eight, enlarged mesenteric lymph nodes (anteroposterior diameter 5-10 mm) in nine, dilated caliber of the superior mesenteric artery or portal vein in seven, free fluid in the abdominal cavity in five, and increased echogenicity of the liver in six. None of these signs was present in the control group.

CONCLUSION

There are several US signs associated with adult celiac disease. None of the signs identified is specific, but a combination of signs is characteristic and indicates suspicion of this disease in a high percentage of cases. US could help to avoid diagnostic delay, especially in patients who have atypical clinical presentations.

Modified small-bowel follow-through: use of methylcellulose to improve bowel transradiance and prepare barium suspension

PURPOSE

To evaluate the efficacy of barium suspension prepared in methylcellulose (MC) in modified small-bowel follow-through (SBFT).

MATERIALS AND METHODS

The authors evaluated 155 patients who underwent modified SBFT with oral administration of MC after ingesting barium suspension. Of these patients, 52 received 40% suspension in MC, 46 received 40% suspension in water, and 57 received 70% suspension in water. Patients were divided into normal (n = 74) and abnormal (n = 81) groups according to the final results. The image quality, transit time to the cecum, and time to and frequency of flocculation were compared for both groups.

RESULTS

In the normal group, the quality of the images in patients receiving 40% suspension in MC or 70% suspension in water was superior to that of images in patients receiving 40% suspension in water. In the abnormal group, the best image quality was achieved for the patients who received 40% suspension in MC. In the normal group, the difference in transit time between the three preparations was not substantial. In the abnormal group, however, the 40% suspension in MC showed the fastest transit time. Use of the 40% suspension in MC helped lower the frequency of flocculation in the normal group.

CONCLUSION

Use of 40% barium suspension in MC is effective for improving the image quality in modified SBFT.