Late bone marrow changes in Hodgkin's disease patients: a characterization with proton chemical shift imaging

Our aim was to measure, by quantitative chemical shift imaging (CSI), the late therapy-induced changes in bone marrow (BM) of Hodgkin's disease (HD) patients. Fifteen HD patients treated with radiotherapy alone and radiochemotherapy (age at treatment between 11 and 50 years; post-treatment interval between 15 and 127 months; applied dose 25.5 to 50 Gy), were studied with a 1.5 T MR imager. For the fat-water separation in-phase and opposed-phase (SE 1200/22) images were generated according to the Dixon method, with a modified post-processing. Long-term fatty replacement was seen in the irradiated BM only. The radiation fields were visualized as areas of high signal intensity in the T1-weighted images. There was a marked increase of the relative fat signal fraction in quantitative CSI without time, dose and age dependent recovery within the investigated ranges. Fatty replacement of the irradiated BM is a long-term effect in HD patients, probably induced by an obliteration of the microvasculature with consecutive fatty metaplasia. (orig.)