Enteric Contrast Research Articles

Gastrointestinal pharmacoradiology, an updated review of medications and gastrointestinal contrasts in abdominal imaging.

The purpose of this article is to review commonly used medications in abdominal radiology including their indications, mechanisms of action, dosages, contraindications, precautions, and adverse reactions. We will clarify common inquiries and address frequently asked questions by patients and clinicians related to their use. In addition, we will explore the indications, advantages and disadvantages, dosages, and contraindications of enteric contrast agents used for CT and fluoroscopic examinations.

Iodinated Contrast Induced Hypothyroidism in the Infant After Enteral Contrast Enema: A Case Report and Systematic Review.

Excessive iodine intake triggers the Wolff-Chaikoff effect resulting in downregulation of thyroid hormone synthesis to prevent hyperthyroidism. Failure to escape the Wolff-Chaikoff effect can be seen especially in (premature born) infants and may result in prolonged iodine induced hypothyroidism. We describe a rare case of a preterm infant who developed severe iodinated contrast induced hypothyroidism after the use and prolonged stasis of enteral iodinated contrast media (ICM). In addition a systematic literature search was performed to evaluate all available data on this complication. A systematic literature search was performed in PubMed and Embase. Studies describing the effect of enteral ICM on thyroid function were considered eligible. The primary outcome was to determine the frequency of contrast induced hypothyroidism in infants after administration of enteral ICM. The premature infant in our center developed severe iodinated contrast induced hypothyroidism after enteral ICM. In total, only two studies met our eligibility data, reporting eight patients. Out of these eight patients, four premature infants developed a contrast induced hypothyroidism after enteral administration of ICM. Data on severity, length and frequency of contrast induced hypothyroidism after exposure to enteral ICM is very scarce. The herein reported case and literature search illustrate the potential severity of the complication and underline the necessity of future studies on this topic. We recommend standardized monitoring of thyroid function after exposure to enteral ICM in newborns to prevent delayed diagnosis of severe contrast induced hypothyroidism until evidence based recommendations can be made.

Assessing Residual Gastric Fluid Volume after Administering Diluted Oral Contrast until One Hour Prior to Anesthesia in Children: An Observational Cohort Study.

Background: Gastric fluid volume has been used as a surrogate marker for pulmonary aspiration risk in studies evaluating fasting protocol safety. This study measured residual gastric fluid volume in children using a protocol in which diluted oral contrast medium was administered up until one hour before anesthesia. Methods: This was a single-center prospective observational cohort trial of 70 children for elective abdominal/pelvic computed tomography (CT). Imaging was performed after diluted enteral contrast medium administration, beginning two hours before and ending at least one hour before induction. For each patient, gastric fluid volume was calculated using an image region of interest. The primary outcome measure was gastric fluid volume measured using the computed tomography image. Results: The median time from the end of contrast administration to imaging was 1.5 h (range: 1.1 to 2.2 h). Residual gastric volume, measured using CT was <0.4 mL/Kg in 33%; ≥0.4 mL/Kg in 67%; and ≥1.5 mL/Kg in 44% of patients. Residual gastric volumes measured using CT and aspiration were moderately correlated (Spearman's correlation coefficient = 0.41, p = 0.0003). However, the median residual gastric volume measured using CT (1.17, IQR: 0.22 to 2.38 mL/Kg) was higher than that of aspiration (0.51, IQR: 0 to 1.58 mL/Kg, p = 0.0008 on differences in paired measures). Three cases of vomiting were reported. No evidence of pulmonary aspiration was identified. Conclusions: Children who receive large quantities of clear fluid up to one hour before anesthesia can have a significant gastric residual volume.

Utility of Enteral Contrast Protocols in Pediatric Adhesive Small Bowel Obstruction: A Prospective Multicenter Observational Study.

Our objective was to determine the utility of enteral contrast-based protocols in the diagnosis and management of adhesive small bowel obstruction (ASBO) for children. Enteral contrast-based protocols for adults with ASBO are associated with decreased need for surgery and shorter hospitalization. Pediatric-specific data are limited. We conducted a prospective observational study between October 2020 and December 2022 at nine children's hospitals who are members of the Western Pediatric Surgery Research Consortium. Inclusion criteria were children aged 1-20 years diagnosed with ASBO who underwent a trial of nonoperative management (NOM) at hospital admission. Comparisons were made between those children who received an enteral contrast challenge and those who did not. The primary outcome was need for surgery. We enrolled 136 children (71% male; median age: 12y); 84 (62%) received an enteral contrast challenge. There was no difference in rate of operative intervention between the no contrast (34.6%) and contrast groups (36.9%; P=0.93). Eighty-seven (64%) were successfully managed nonoperatively with no difference in median length of stay (P=0.10) or rate of unplanned readmission (P=0.14). Among the 49 children who required an operation, there was no significant difference in time from admission to surgery or rate of small bowel resection based on prior contrast administration. The addition of enteral contrast-based protocols for management of pediatric ASBO does not decrease the likelihood of surgery or shorten hospitalization. Larger randomized studies may be needed to further define the role of radiologic contrast in the management of ASBO in children.

S101 Colosplenic Fistula in Inflammatory Bowel Disease: A Scoping Review

Background: A colosplenic fistula is an extremely rare complication of Crohn’s disease (CD) first described in a 1985 case report that remains relatively poorly understood due to its infrequent incidence. With only a few colosplenic fistulas reported worldwide, the diagnosis and management of patients with colosplenic fistula is vague. Hence, we described a review of patients with colosplenic fistula due to inflammatory bowel disease (IBD) to summarize colosplenic fistula etiology, clinical features, diagnosis, management, and prognosis to help clinicians gain a better understanding of this unusual complication and provide an aid if it were to be encountered. Methods: We conducted a systematic search of articles published from 1946 to June 2022 in Ovid MEDLINE, Ovid EMBASE, Scopus, Web of Science, and Wiley Cochrane Library to identify patients with colosplenic fistulas. Studies with etiology of IBD were included. Results: The search strategy retrieved 141 references and a total of 4 studies reporting 4 patients with colosplenic fistula in the setting of IBD were analyzed. Most patients (75%) were male, with a median age of 33 years. All 4 (100%) patients had prior diagnosis of CD, with a median time of 12.5 years since diagnosis. Two patients had extraintestinal manifestations of IBD (uveitis, erythema nodosum, ankylosing spondylitis). Three patients were on long-term sulfasalazine and 2 (50%) were on corticosteroids. Etiology: Our review revealed that patients with CD formed a fistula tract from their colon to the adjacent spleen due to chronic, transmural inflammation and ulceration. Active inflammation was observed in the adjacent colon on pathology or endoscopy. Clinical features: Most patients presented with complaints of recurring fever, leukocytosis, and left upper quadrant pain or discomfort. Diagnosis: The most widely-used and effective diagnostic imaging was the computed tomography (CT) scan. CT with intravenous (IV) contrast helped identify splenic lesions and colonic thickening, while enteral contrast was useful to identify fistula tract. Chest X-rays, plain abdominal films, and colonoscopy were not essential in diagnosing a colosplenic fistula. Use of magnetic resonance imaging (MRI) was not reported in any case. Management: Most patients were promptly treated with IV fluid and broad-spectrum antibiotics. Only one patient was started on IV steroids. Most patients underwent surgical intervention of colosplenic fistulas with splenectomy and segmental resection of the affected col1on. One case offered temporary diverting loop ileostomy with plans for future splenectomy and colectomy. Prognosis: Symptoms resolved with surgical intervention. No postoperative complications or mortalities were reported. Conclusion(s): Our review revealed that patients with Crohn’s disease can form a fistula tract from their diseased colon to the adjacent spleen due to transmural inflammation. Diagnosis can be achieved with a CT scan with enteral and/or intravenous contrast. Most colosplenic fistulas can be successfully treated with laparotomy, splenectomy, and resection of the affected colon with low rate of postoperative complications. Our pooled analysis of available colosplenic fistula cases may serve as an aid for diagnosis and management of this rare entity.

An Incidental Discovery of a Serious Complication

An Incidental Discovery of a Serious Complication

Upper Gastrointestinal Fluoroscopic Examination: A Traditional Art Enduring into the 21st Century.

Upper Gastrointestinal Fluoroscopic Examination: A Traditional Art Enduring into the 21st Century.

Performance of Multidetector Computed Tomography and Negative Versus Positive Enteric Contrast for Evaluation of Gastrointestinal Neuroendocrine Neoplasms.

Routine computed tomography (CT) scans are thought to have poor performance for detection of gastrointestinal (GI) neuroendocrine neoplasms (NENs), which leads to delayed workup. Detection of even 1 bowel tumor can guide diagnostic workup and management. The purposes of this study were to assess the accuracy of multidetector computed tomography (MDCT) and to compare negative versus positive enteric contrast in detecting at least 1 GI tumor per patient with suspected or confirmed diagnosis of a NEN. This retrospective study included 107 patients with intravenous and oral contrast (65 positive, 40 negative, and 2 no oral contrast) abdominopelvic MDCT. Two abdominal radiologists independently analyzed the CTs for detection and localization of bowel NENs. Surgical pathology was considered the reference standard. Analyses included κ and summary statistics, McNemar test, Pearson χ2 test, and Fisher exact test. Among the 107 CT scans, there were 30 pathology negative studies and 77 studies with positive pathology for GI NEN. Interreader agreement for CT evaluation was substantial (κ = 0.61). At least 1 GI NEN per patient was detected with 51% to 53% sensitivity, 87% to 93% specificity, 91% to 95% positive predictive value (PPV), 42% negative predictive value, and 63% accuracy for each reader, and 57% accuracy when only the concordant (ie, matching) results of the 2 readers were considered. Computed tomography scans with negative enteric contrast had significantly higher sensitivity for concordant results than CTs with positive enteric contrast (58% vs 30%, P = 0.01). Specificity (100% vs 95%, P = 0.5), PPV (100% vs 93%, P = 0.49), negative predictive value (39% vs 39%, P = 0.99), and accuracy (67% vs 51%, P = 0.10) were not significantly different for negative versus positive enteric contrast for the concordant results. There was no significant difference in GI NEN localization between the readers. Routine MDCT with either positive or negative enteric contrast can detect at least 1 GI tumor per patient with more than 90% PPV and more than 50% accuracy in patients suspected of GI NEN. Using negative enteric contrast improves sensitivity for GI NEN versus positive enteric contrast. In addition, there is high accuracy in localizing the bowel tumor with positive or negative enteric contrast, which may guide surgery. Radiologists should have heightened awareness that evaluating such scans closely may lead to detection of primary bowel NENs at a higher rate than previously reported.

Bowel Peristalsis Artifact on Dual-Energy CT: In Vitro Study on the Influence of Different Dual-Energy CT Platforms and Enteric Contrast Agents.

BACKGROUND. The value of dual-energy CT (DECT) for bowel wall assessment is increasingly recognized. Although technical improvements reduce peristalsis artifact in conventional CT, the effects of peristalsis on DECT image reconstructions remain poorly studied. OBJECTIVE. The purpose of this study was to evaluate the influence of different DECT scanners and enteric contrast agents on the severity of bowel peristalsis artifact in vitro. METHODS. To simulate bowel peristalsis, a 3-cm-diameter corrugated hollow tube representing the bowel was oscillated constantly in the z-axis within a larger water-filled cylinder. The bowel was serially filled with air, water, and iodinated or experimental dark contrast material and scanned on four different DECT platforms (spectral detector, rapid peak kilovoltage switching, split filter, and dual source) to reconstruct 120-kVp-like and iodine images. Two readers rated each image reconstruction for artifact severity from 0 (none) to 3 (severe) and recorded the degree to which iodine images depicted bowel wall hyperattenuation on 120-kVp-like images as artifactual. Artifact severity scores were compared by ANOVA with Bonferroni correction. RESULTS. Interrater agreement on artifact scores was excellent (intraclass correlation coefficient, 0.82 [95% CI, 0.79-0.84]). For 120-kVp-like images, mean peristalsis artifact scores were lower (all p < .001) for split-filter (1.47) and dual-source (1.86) scanners than for spectral-detector (2.58) and rapid-kilovoltage-switching (2.74) scanners. Compared with those on 120-kVp images, peristalsis artifacts on iodine images were less severe for spectral-detector (score, 1.03; p < .001) and rapid-kilovoltage-switching (2.09; p < .001) systems but more severe for dual-source (2.77; p < .001) and split-filter (2.62; p < .001) systems. Peristalsis artifact was rated less severe with experimental dark bowel contrast medium (score, 1.79) than with other bowel contrast agents (all p < .001). Iodine images helped identify bowel wall hyperattenuation as artifactual in 94.7% of reviewed cases for spectral-detector and 40.7% of cases for rapid-kilovoltage-switching scanners. CONCLUSION. For spectral-detector and rapid-kilovoltage-switching DECT, iodine images minimize peristalsis artifact, but for dual-source and split-filter DECT, mixed 120-kVp-like images are preferred. Compared with iodinated contrast material and water, experimental dark bowel contrast material reduces peristalsis artifact. CLINICAL IMPACT. Knowledge of the preferred images for reducing peristalsis artifact can lessen the effect of peristalsis on clinical DECT interpretation. Dark enteric contrast agents, when they become clinically available, may further reduce the effects of peristalsis.

Feasibility of Abdominal Magnetic Resonance Imaging in Patients With Residual Concentrated Enteric Contrast After Fluoroscopic Abdominal Examination.

This study aimed to evaluate the image quality, image artifacts, radiologist confidence, and ability to provide definitive diagnosis for all patients with magnetic resonance imaging (MRI) performed after an abdominal fluoroscopic examination and to determine the utility of MRI in this setting. Thirty-one MRI examinations performed a median of 2 days after fluoroscopic bowel evaluation (barium, n = 13; iodine, n = 18), 20 within 3 days of MRI, were retrospectively reviewed. The image quality, artifact emanating from bowel, inhomogeneity artifact, radiologist confidence, ability to render a definitive diagnosis, and identification of emergent or important findings for all MRI examinations were assessed. These same features were evaluated on 5 computed tomographies performed after fluoroscopy (before the MRI) in the same cohort. All 31 MRI examinations performed after fluoroscopic studies with concentrated barium or iodine solutions were diagnostic for answering the clinical question according to radiologist and report review, regardless of magnet strength and type of fluoroscopic contrast ingested. Magnetic resonance imaging after fluoroscopy had excellent overall image quality (mean score, 4.74/5), minimal to no artifact emanating from bowel (mean, 4.63/5), minimal inhomogeneity artifact (mean, 4.38/5), and excellent diagnostic confidence (mean, 4.98/5). No additional imaging was necessary for diagnosis after MRI. Computed tomography after fluoroscopy had lower overall image quality, more image artifacts, and lower diagnostic confidence (P < 0.05). Magnetic resonance imaging is a useful tool for evaluating patients with retained concentrated enteric contrast from recent fluoroscopic examinations. In the absence of contraindication, MRI should be considered in the evaluation of urgent clinical problems in patients who recently underwent a fluoroscopic bowel evaluation.

Attitudes Affecting Decision-Making for Use of Radiologic Enteral Contrast in the Management of Pediatric Adhesive Small Bowel Obstruction: A Survey Study of Pediatric Surgeons

BackgroundPediatric surgeons are often asked to treat clinical problems for which little high-quality data exist. For adults with adhesive small bowel obstruction (ASBO), water soluble contrast-based protocols are used to guide management. Little is known about their utility in children. We aimed to better understand key factors in clinical decision-making processes and integration of adult based data in pediatric surgeon's approach to ASBO. MethodsWe administered a web-based survey to practicing pediatric surgeons at institutions comprising the Western Pediatric Surgery Research Consortium. ResultsThe response rate was 69% (78/113). Over half of respondents reported using contrast protocols to guide ASBO management either routinely or occasionally (n = 47, 60%). Common themes regarding the incorporation of adult-based data into clinical practice included the need to adapt protocols for pediatric patients, the dearth of pediatric specific data, and the quality of the published adult evidence. ConclusionsOur findings demonstrate that pediatric surgeons use contrast-based protocols for the management of ASBO despite the paucity of pediatric specific data. Furthermore, our survey data help us understand how pediatric surgeons incorporate adult based evidence into their practice.

Does routine postoperative contrast radiography improve outcomes for patients with perforated peptic ulcer? A multicenter retrospective cohort study

BackgroundPerforated peptic ulcer is a morbid emergency general surgery condition. Best practices for postoperative care remain undefined. Surgical dogma preaches practices such as peritoneal drain placement, prolonged nil per os, and routine postoperative enteral contrast imaging despite a lack of evidence. We aimed to evaluate the role of postoperative enteral contrast imaging in postoperative perforated peptic ulcer care. Our primary objective was to assess effects of routine postoperative enteral contrast imaging on early detection of clinically significant leaks. MethodsWe conducted a multicenter retrospective cohort study of patients who underwent repair of perforated peptic ulcer between July 2016 and June 2018. We compared outcomes between those who underwent routine postoperative enteral contrast imaging and those who did not. ResultsOur analysis included 95 patients who underwent primary/omental patch repair. The mean age was 60 years, and 54% were male. Thirteen (14%) had a leak. Eighty percent of patients had a drain placed. Nine patients had leaks diagnosed based on bilious drain output without routine postoperative enteral contrast imaging. Use of routine postoperative enteral contrast imaging varied significantly between institutions (30%–87%). Two late leaks after initial normal postoperative enteral contrast imaging were confirmed by imaging after a clinical change triggered the second study. Two patients had contained leaks identified by routine postoperative enteral contrast imaging but remained clinically well. Duration of hospital stay was longer in those who received routine postoperative enteral contrast imaging (12 vs 6 days, median; P = .000). ConclusionRoutine postoperative enteral contrast imaging after perforated peptic ulcer repair likely does not improve the detection of clinically significant leaks and is associated with increased duration of hospital stay.

Invited Commentary: Key Concepts of CT for Penetrating Abdominopelvic Injuries.

Invited Commentary: Key Concepts of CT for Penetrating Abdominopelvic Injuries.

English

BACKGROUND Small bowel imaging often questions clinicians due to its long, tortuous and undulating morphology. The current study was undertaken to establish the efficacy of multidetector computed tomography (MDCT) enterography in the evaluation of small bowel diseases using iso-osmotic mannitol as oral contrast agent. METHODS A prospective observational study was conducted among thirty patients (mean age 40 years; range 14 - 66 years), 16 males and 14 females presenting with clinical suspicion of small bowel diseases based on clinical, laboratory or other imaging investigations underwent CT enterography on a 128 slice CT scanner using isoosmotic mannitol as neutral enteral contrast. RESULTS Intestinal tuberculosis was the most common diagnosis. Non neoplastic cases predominantly showed segmental symmetrical involvement with target pattern of enhancement. Small bowel tumours (adenocarcinoma) were seen in 2 cases. Neoplasms were associated with focal asymmetrical involvement with heterogeneous enhancement pattern. Computerized tomography enterography (CTE) clearly depicted the site, level and cause of the obstruction in all the patients with a sensitivity and specificity of 96 % and 100 % respectively. Diagnostic accuracy of CTE in detection of small bowel diseases came out to be 98 %. CONCLUSIONS CT enterography is an effectual, non-invasive, well-tolerated, sensitive and specific imaging modality for the evaluation of small bowel diseases which provides superior assessment of the intraluminal, mural and extraintestinal pathologies. KEY WORDS CT enterography, mannitol, Tuberculosis, Small Bowel

Utility of enteric contrast material in abdominal penetrating trauma: A narrative review

Penetrating trauma is an important cause of morbidity and mortality. With the possibility of conservative management for hemodynamically stable trauma patient, computed tomography (CT) has become an important tool in diagnosis and management of penetrating trauma. There have been multiple studies examining the utility and lack of perceived benefit of using enteric contrast material in the initial CT evaluation. We provide a narrative review of the surgical and radiological literature, offer our own protocol for how to approach the imaging of patients with suspected bowel injury following penetrating traumatic injury and discuss the potential of using enteric contrast material.

Gastrografin can be detected in ex vivo biological specimens by dual-energy CT scanning.

Dual-energy CT is able to distinguish between materials based on differences in X-ray absorption at different X-ray beam energies. The strong k-edge photoelectric effect of materials with a high atomic number makes this modality ideal for identifying iodine-containing compounds. We aim to evaluate dual-energy CT for the detection of Gastrografin (GG) (diatrizoate, Bayer PLC, Reading, UK) enteric contrast medium and validate the conditions for the measurement in ex vivo samples. Dual-energy CT acquisitions were performed to detect Gastrografin in serial dilutions of water, saline and body fluids. We also evaluated the stability of Gastrografin solutions over time at room temperature. Stool specimens were examined to validate the proposed study protocol for clinical applications. Concentrations as low as 0.2% of Gastrografin were reproducibly detected in vitro and ex vivo samples by DECT, with linear readings ranging from 0.2% to 25% Gastrografin. Gastrografin was shown to be stable in ex vivo biological samples, and there was no difference in detection over time. Gastrografin was detected in stool specimens when administered orally. The detection curves followed the expected saturation effect at high concentrations of iodine. Dual-energy CT offers a convenient, quick, reliable and reproducible method for detecting and quantifying the presence of Gastrografin in ex vivo clinical specimens. Biological solutions containing Gastrografin are stable over time. A minimum dilution level of 25% is suggested to avoid beam saturation and inaccurate results.

Enterocutaneous Fistula: A Simplified Clinical Approach.

A “fistula” is an abnormal connection between two epithelial surfaces. Fistulae are named based on the two surfaces or lumens they connect to. Fistulae form due to loss of wall integrity from an underlying insult, leading to the penetrance of an adjacent organ or epithelized surface. Common causes of small bowel fistulae include sequelae of surgical intervention, foreign body, bowel diverticula, Crohn's disease, malignancy, radiation, and infection. A histopathological analysis displays acute and/or chronic inflammation due to the underlying pathology.A thorough history and physical examination are important components of patient evaluation. Generally, patients will present with non-specific constitutional symptoms in addition to local symptoms attributed to the fistula. In rare instances, symptoms may be severe and life-threatening. Initial laboratory workup includes complete blood count, comprehensive metabolic panel, and lactate level. Radiologic imaging is useful for definitive diagnosis and helps delineate anatomy. In practice, computed tomography (CT) is the initial imaging modality. The addition of intravenous or enteric contrast may be helpful in certain situations. Magnetic resonance imaging (MRI) may also be used in special circumstances. Invasive procedures, such as endoscopy, can assist in the evaluation of mucosal surfaces to diagnose pathology such as inflammatory processes.Appropriate management should include optimizing nutritional status, delineating fistulous tract anatomy, skincare, and managing the underlying disease. A non-operative approach is generally accepted as the initial approach especially in the acute/subacute setting. However, operative intervention is indicated in the setting of failed non-operative management. Successful management of small bowel fistulae requires a multidisciplinary team approach.To conclude, a small bowel fistula is a complex clinical disease, with surgical intervention being the most common cause in developed countries. The non-operative approach should be trialed before an operative approach is considered.

Manganese threonine chelate-a new enteric contrast agent for MRI: a pilot study on rats.

Enteric contrast agents are important in gastrointestinal MRI. However, no currently available agent is well established as the standard of care. In this study, in vitro relaxivities of manganese threonine chelate (Mn-Thr), a common nutritional food supplement, were measured at 1.5 T and 3 T with further investigation of its efficacy and safety in vivo as an enteric contrast agent. According to the calculated relaxivities, T1 W and T2 W TSE sequences of Mn-Thr solutions at different concentrations were acquired, and the optimal concentration for dark lumen imaging on both T1 W and T2 W images was determined in vitro. To validate the optimal concentration in vivo, eight Sprague-Dawley rats were randomly divided into two groups. Each group received rectal injection of either 2.00 g/L (about 3.80 mM) Mn-Thr or saline as an enteric contrast agent and underwent MRI. After a time interval of one week, the same procedures were repeated with the alternative contrast agent. Animals were sacrificed after the second MRI. Tissue manganese quantification and histopathological examination were obtained. Qualitative MR image quality assessments were performed and compared between Mn-Thr and saline. Measured T1 and T2 relaxivities of Mn-Thr were significantly higher than those of MnCl2 in vitro (p < 0.05). At the concentration of 2.00 g/L (about 3.80 mM), Mn-Thr produced a dark lumen on T1 W and T2 W images both in vitro and in vivo. Compared with saline, Mn-Thr showed significantly more homogenous luminal signal and increased bowel wall conspicuity in image quality assessments. Tissue manganese concentrations were not significantly different between two groups. Histopathological examinations were normal in both groups. Our data suggest that Mn-Thr possesses favorable paramagnetic properties and can create a homogenous dark lumen on T1 W and T2 W images without obvious side effects in healthy rats. As a commercially available nutritional food supplement, Mn-Thr appears to be a promising enteric contrast agent for MRI.

Preparation, Technique, and Imaging of Computed Tomography/Magnetic Resonance Enterography

CT enterography and magnetic resonance (MR) enterography are widely used imaging modalities used to examine the small bowel. These radiologic tests are distinguished from routine abdominopelvic CT and MRI by the oral ingestion of a large amount of neutral contrast to distend the small bowel before scanning. For achievement of high quality, diagnostic images and proper technique are required. Conducted protocols still vary in patient preparation, enteric contrast, and CT and MRI acquisition sequences, resulting in heterogeneous diagnostic accuracy. The purpose of this article is to review the processes and techniques that optimize CT/MR enterography for patients with suspected Crohn's disease or other small bowel diseases.

Role of multidetector computed tomography enterography in the evaluation of small bowel diseases

Background: Small bowel imaging is technically challenging due to the difficulty in displaying the long and serpentine small bowel in entirety and intrinsic motion peristalsis and positional changes caused by breathing. Multidetector computed tomography (MDCT) enterography with the use of neutral enteric contrast permits an excellent assessment of the small bowel pathologies. Objective: The objective of this study is to determine the radiological features of small bowel diseases with respect to the presence, localization, causes, and associated complications with MDCT enterography. Materials and Methods: This is a single-center, cross-sectional, analytical study, which was carried over a period of 2 years on 43 patients, in a medical institute at department of radiodiagnosis. The study was conducted with Philips Brilliance 64-Slice computed tomography machine with neutral enteric contrast and intravenous contrast agents with arterial and enteric or portal phases. Imaging findings were correlated clinically, surgically, and histopathologically. Results: Out of the 43 cases, nine cases (20.93%) were of malignant pathologies, 20 cases were of nonmalignant mural pathologies (46.51%), and 14 cases were other intraluminal or extraluminal pathologies. The common bowel wall patterns found in nonneoplastic pathologies were segmental (50%), symmetrical (70%), mild-to-moderate wall thickening (70%), homogeneous and stratified attenuation patterns (95%), whereas segmental (80%), asymmetrical (80%), marked wall thickening (100%), and heterogeneous enhancement patterns (60%) with distal bowel involvement in primary malignancy cases. Mean wall thickness in malignant pathologies (21.56 ± 15.68 mm) was statistically significantly higher than mean wall thickness of nonmalignant pathologies (7.85 ± 3.69 mm) with P value of 0.031 ( Conclusion: MDCT enterography is a powerful diagnostic tool for the study of small bowel disorders, including inflammatory disease, small bowel neoplasms, and mechanical obstruction.