Mastocytosis: magnetic resonance imaging patterns of marrow disease

Objective. To report the bone marrow MRI findings of patients with mastocytosis and correlate them with clinical, pathologic, and radiographic features. Design and patients. Eighteen patients with mastocytosis had T1-weighted spin echo and short tau inversion recovery MRI of the pelvis at 0.5 T. In each patient the MR pattern of marrow disease was classified according to intensity and uniformity and was correlated with the clinical category of mastocytosis, bone marrow biopsy results, and radiographic findings. Results. Two patients had normal MRI scans and normal bone marrow biopsies. One patient had a normal MRI scan and a marrow biopsy consistent with mastocytosis. Fifteen patients had abnormal MRI scans and abnormal marrow biopsies. There were several different MR patterns of marrow involvement; none was specifically associated with any given clinical category of mastocytosis. Fifteen of the 18 patients had radiographs of the pelvis; of those, 13 with abnormal MRI scans and abnormal marrow biopsies had the following radiographic findings: normal (nine); sclerosis (three); diffuse osteopenia (one). Conclusion. While radiographs are very insensitive for the detection of marrow abnormalities in mastocytosis, MRI is very sensitive and may display several different patterns of marrow involvement.