MR Findings of Acute Graft-versus-Host Disease Involving Gastrointestinal Tracts

PURPOSE: To evaluate the MR findings of gastrointestinal graft-versus-host disease (GVHD) after allogenic bone marrow transplantation. MATERIALS AND METHODS: Five patients (M:F=3:2, age range: 9-58 years) with suspected gastrointestinal GVHD underwent abdominal MRI, and the findings were evaluated. Because of acute myelocytic leukemia (n=4) or non-Hodgkin's lymphoma (n=1), all had undergone allogenic bone marrow transplantation 2-6 (mean, 3.5) weeks earlier. T2-weighted half-Fourier acquisition snapshot turbo spin-echo, T1-weighted spoiled gradientecho (SGE), and postcontrast T1-weighted SGE MR imaging, with and without fat-suppression, was performed. RESULTS: All five patients showed bowel wall thickening and marked contrast enhancement in the jejunum (n=5), ileum (n=4), duodenum (n=3), sigmoid colon (n=3), gastric antrum (n=2), and rectum (n=2). Bowel wall thickening showed a target appearance in the jejunum (n=2, 40.0%), ileum (n=1, 25.0%), sigmoid colon (n=1, 33.3%), and rectum (n=1, 50.0%), while the remaining cases showed diffuse wall thickening without layering. Small amount of ascites was noted in four patients (80%), and multiple small conglomerated retroperitoneal lymph nodes in three (60%). In all patients, a signal intensity of slightly enlarged liver due to iron overload secondary to multiple blood transfusions, gave rise to decreased signal intensity at both T1-and T2-weighted MR imaging. CONCLUSION: In patients with GVHD, the commonly noted MR findings were bowel wall thickening with contrast enhancement, ascites and retroperitoneal lymphadenopathy.

Usefulness of MR Imaging for Diseases of the Small Intestine: Comparison with CT

OBJECTIVE: To evaluate the usefulness of MR imaging for diseases of the small intestine, emphasizing a comparison with CT. MATERIALS AND METHODS: Thirty-four patients who underwent both CT and MR imaging using FLASH 2D and HASTE sequences were analyzed. All patients had various small bowel diseases with variable association of peritoneal lesions. We compared the detectabilities of CT and MR imaging using different MR pulse sequences. The capability for analyzing the characteristics of small intestinal disease was also compared. RESULTS: MR imaging was nearly equal to CT for detecting intraluminal or peritoneal masses, lesions in the bowel and mesentery, and small bowel obstruction, but was definitely inferior for detecting omental lesions. The most successful MR imaging sequence was HASTE for demonstrating bowel wall thickening, coronal FLASH 2D for mesenteric lesions, and axial FLASH 2D for omental lesions. MR imaging yielded greater information than CT in six of 12 inflammatory bowel diseases, while it was equal to CT in six of seven neoplasms and inferior in five of seven mesenteric ischemia. In determining the primary causes of 15 intestinal obstructions, MR imaging was correct in 11 (73%) and CT in nine (60%) patients. CONCLUSION: MR imaging can serve as an alternative diagnostic tool for patients with suspected inflammatory bowel disease, small intestinal neoplasm or obstruction. is a high-speed, heavily T2-weighted sequence with a great sensitivity for fluid (11). This advance may make it possible to use breath-hold turbo spin-echo MR.