In this study, researchers from the United States evaluated benign versus malignant bowel obstruction on unenhanced and gadolinium-enhanced spoiled gradient-echo magnetic resonance (MR) images.
The team assessed 48 patients with malignancy and bowel obstruction who underwent abdominal and pelvic MR imaging.
Each study was evaluated by 2 blinded radiologists. They looked for dilated bowel, transition point, level of obstruction, obstructing mass, mural thickening and enhancement, and peritoneal disease.
The team recorded benign obstruction if no mass was present, and if present, whether mural thickening was segmental or diffuse.
Malignant bowel obstruction was recorded if there was a mass, a disseminated abdominal tumor, or focal mural thickening.
|Malignant bowel obstruction was present in 24 of 25 patients with an obstructing mass.|
The team then compared the MR images with surgical findings, follow-up imaging studies, and clinical outcome.
They used Chi2 and Fisher exact tests to identify the relationship between the MR features, and benign versus malignant obstructions.
The researchers found that bowel obstruction had a benign cause in 19 patients, and a malignant cause in 29 patients.
One of the radiologists correctly identified benign bowel obstruction in 17 of 19 patients, and malignant bowel obstruction in 27 of 29 patients. Their sensitivity for characterizing malignant obstruction was 93%, specificity 89%, and accuracy 92%.
The second radiologist identified benign bowel obstruction in 18 of 19 patients, and malignant bowel obstruction in 26 of 29 patients. Their sensitivity in detecting malignant obstruction was 90%, specificity 95%, and accuracy 92%.
The team determined that malignant bowel obstruction was present in 24 of 25 patients with an obstructing mass.
They also found that all 16 patients with focal mural thickening had malignant obstruction.
Benign obstruction was present in 4 of 5 patients with diffuse mural thickening.
The team also identified segmental mural thickening in 4 patients with serosal metastases, and in 11 patients with benign bowel obstruction.
In addition, they determined that more extensive peritoneal thickening, and enhancement correlated with malignant obstruction.
Dr Russell Low's team concluded, "In patients with malignancy who have symptoms indicative of bowel obstruction, gadolinium-enhanced MR imaging can help distinguish benign from malignant causes of bowel obstruction".