Distribution of serouslike bone marrow changes in the lower limbs of patients with anorexia nervosa: predominant involvement of the distal extremities.

OBJECTIVE: To assess the distribution of marrow changes in the bones of the lower limbs of patients with anorexia nervosa (AN) and to correlate the importance of the extent of marrow changes with clinical and hematologic data. MATERIALS AND METHODS: The frequency of serouslike marrow (low signal intensity on T1-weighted images and very high signal intensity on T2-weighted images) was determined with MR imaging in the bones of the feet, distal tibias, and proximal femurs in 19 patients with AN. RESULTS: Serouslike marrow was found with an increasing frequency from proximal to distal in the lower-limb bones (femur, 31%; distal phalanx of the first toe, 79%). The patients with abnormal femoral marrow (n = 6) were more severely emaciated and had lower leukocyte and neutrophil counts than the patients with normal femoral marrow (n = 13). Among these patients, the six patients with at least two involved bones in the feet had lower blood cell counts than the seven patients with fewer than two involved bones. CONCLUSION: In the lower limbs of patients with AN, marrow changes predominate in the distal aspects. This distribution pattern is the reverse of that seen in most bone marrow disorders but is similar to the normal conversion of hematopoietic to fatty marrow. The importance of the blood cell count changes is correlated with the extent of marrow changes in the limbs.