Magnetic resonance imaging of femoral marrow cellularity in hypocellular haemopoietic disorders

AIM: Magnetic resonance imaging (MRI) of the femora was used to investigate the marrow cellularity during the evolution of non-transplanted aplastic a naemia (AA) and hypocellular myelodysplastic syndrome (h-MDS) in order to i nvestigate the relationship between this cellularity and disease progressio n. METHODS: Magnetic resonance imaging was performed in adult patients with pa ncytopaenia and hypocellular bone marrow. Coronal T1 weighted and STIR imag es were obtained, and analysed semiquantitatively. These data were compared with diagnosis, peripheral blood counts and bone marrow histology at diagn osis and at the time of the MRI examination. RESULTS: Patients were examined 2-84 months after diagnosis (median, 16 mon ths). In AA, 11/13 patients showed a fatty, faint or nodular pattern. In h- MDS, the majority of the patients (10/14) had a scattered or uniform signal pattern. In AA, a significant correlation was found between the degree of femoral cellularity and disease duration. Only three cases had diffuse high signal on STIR: among them, one had paroxysmal nocturnal haemoglobinuria a nd the other developed acute leukaemia 3 months after MRI examination. Four patients have died: three with h-MDS presenting a scattered (two cases) or a uniform (one case) MRI signal and one with AA (with a nodular pattern). CONCLUSION: In AA, femoral haemopoiesis is usually not pronounced, and if p resent, does not contribute to the improvement of blood counts. In h-MDS, p atients with discrete femoral haemopoiesis had an improvement in their bloo d counts with disease duration, similar to that found in AA. Conversely, in patients with pronounced femoral cellularity, blood counts remained stable or had deteriorated since diagnosis. This favours the hypothesis that, as is observed in MDS with a hypercellular marrow, scattered or uniform marrow patterns in femoral MRI are signs of more aggressive disease. Lorand-Metze , I. et al. (2001) Clinical Radiology 56, 107-110. (C) 2001 The Royal Colle ge of Radiologists.