MAGNETIC-RESONANCE-IMAGING FOR DIAGNOSIS OF SHWACHMANS SYNDROME

Shwachman's syndrome is a rare disease characterized by the associatio n of chronic diarrhea due to exocrine pancreatic insufficiency, metaph yseal dysostosis, and neutropenia. The diagnosis requires demonstratio n of lipomatosis, or fatty replacement of the pancreas, which is the t ypical pathological feature of the disease. Magnetic resonance imaging (MRI) was performed in 13 patients with exocrine pancreatic insuffici ency, 7 with Shwachman's syndrome, 2 with Pearson's syndrome, 1 with n ormal sweat test later diagnosed as cystic fibrosis, and 3 without ide ntified syndrome, and in 7 control children. Ultrasonography in the pa tients did not differentiate between atrophy and lipomatosis and could not be performed in 3. MRI visualized the pancreas in all. The same i mage was noted in all patients with Shwachman's syndrome with a normal -sized or enlarged pancreas, a hyperintense signal on T-1- and T-2-wei ghted image, and a null signal on short time inversion recovery (STIR) -weighted image, characteristic of fat. In all other patients, the fin dings were very different: The pancreas was a small structure surround ed with fat. In 1 patient without identified syndrome, the pancreas ap peared to be partially replaced with fat. MRI is an excellent imaging technique to correlate the nature of a tissue and its radiological rep resentation, especially fat, which gives a very typical signal. In our brief series of patients with Shwachman's syndrome, MRI had 100% posi tive predictive value in demonstrating lipomatosis. In atypical cases of pancreatic insufficiency in which some of the clinical features of Shwachman's syndrome are absent, MRI is an invaluable aid in the diagn ostic procedure.