Overlap syndrome of autoimmune chronic liver diseases: MRI findings.

PURPOSE: To describe the MR findings of overlap syndromes of autoimmune chronic liver diseases. METHODS: Review of clinical and radiological databases between March 2001 and July 2008 for patients with a clinical diagnosis and liver biopsy features compatible with overlap syndrome who had also undergone an abdominal MRI yielded 15 adult patients. MR features of overlap syndrome were reviewed by two radiologists by consensus. Two radiologists independently reviewed the studies in a blinded fashion for primary sclerosing cholangitis (PSC)-type or non-PSC-type features to assess interobserver agreement. RESULTS: PSC-type and non-PSC-type overlap syndrome had distinctive MR features. In the consensus review, all 12 patients with PSC-type overlap syndrome were correctly identified. Imaging findings included central macroregeneration (N = 9), peripheral atrophy (N = 7), biliary duct beading (N = 12), biliary dilation (N = 10), or a combination of all four findings (N = 7). The presence of any of the first three features had 100% specificity for a PSC-type overlap syndrome. Patients with non-PSC-type overlap (N = 3) showed relatively normal liver morphology (N = 3) and minimal biliary ductal dilatation in one patient. There was good interobserver agreement (kappa = 0.76). CONCLUSION: Patients with serologic or pathologic evidence of AIH or PBC with imaging features of PSC may have PSC-type overlap syndrome.

MR imaging findings of small bowel hemorrhage: two cases of mural involvement and one of perimural.

PURPOSE: To demonstrate the MR appearance of small bowel wall hemorrhage. MATERIALS AND METHODS: A search was performed of the clinical information system (CIS) and the abdominal MRI databases of our institution for patients diagnosed with bowel hemorrhage on MRI between January 1, 2000, and July 31, 2008. All patients were imaged using a protocol that included noncontrast T1- and T2-weighted images and postgadolinium gradient echo images. RESULTS: Two male patients, 44 and 55 years of age, were identified with small bowel mural hemorrhage, one in the duodenum and one in the jejunum. A third patient, a 66-year-old man, was identified with perimural hematoma. The following imaging features were observed: for mural hemorrhage, mural-based increased signal intensity (SI) in the bowel wall on fat suppressed T1-weighted images, variable increased SI on T2-weighted images and no appreciable enhancement on the postcontrast T1-weighted image; perimural hemorrhage exhibited normal thickness low SI wall on T2-weighted single shot images, with ill-defined material surrounding the bowel. SI features of this material, was similar to mural-based abnormality. CONCLUSION: In two patients with small bowel wall hemorrhage, the wall showed increased thickness with increased SI on noncontrast T1-weighted images and lack of enhancement on postgadolinium images. Perimural hematoma showed an intact normal thickness wall that was low SI on T2 with surrounding material that was high SI on noncontrast T1-weighted images and did not enhance.