MRI GADOLINIUM ENHANCEMENT OF BONE-MARROW - AGE-RELATED-CHANGES IN NORMALS AND IN DIFFUSE NEOPLASTIC INFILTRATION

Objective: To quantify gadolinium-related enhancement in the bone marr ow of the spine in normals and in patients with homogeneous diffuse ma lignant bone marrow infiltration. Design and patients: The patients co nsisted of two groups: group 1 comprised 94 healthy adults (18-86 year s) without bone marrow disease and group 2 comprised 30 patients with homogeneous diffuse malignant bone marrow infiltration due to myeloma (n=20) or breast carcinoma (n=10). All patients received intravenous g adopentetate dimeglumine (Gd-DTPA), 0.1 mmol/kg body weight. Pre- and postcontrast signal intensity (SI) on T1-weighted spin-echo (SE) image s (TR/TE: 572 ms/15 ms) was measured over a region of interest (ROI) a nd the percentage SI increase was calculated. The results were confirm ed by bone marrow biopsy (n=20) and clinical parameters (n=10). Dynami c contrast-enhanced studies using a spoiled gradient-recalled-echo (GR E) sequence (TR/TE/alpha: 68 ms/6 ms 75 degrees) were performed in 10 controls with normal bone marrow. Results and conclusion: Contrast mat erial enhancement in healthy persons can vary greatly (range 3-59%, me an 21%, SD 11%). With increasing age there is a significant decrease i n contrast enhancement (Pearson's correlation, P<0.01). The percentage SI increase in patients with intermediate-grade (biopsy 20-50 vol%) a nd high-grade (biopsy >50 vol%) diffuse malignant bone marrow infiltra tion was significantly higher than in normals (mean 67%, SD 34%, P<0.0 01). Low-grade (biopsy <20 vol%) diffuse malignant bone marrow infiltr ation can not be assessed by non-enhanced T1-weighted SE images or Gd- DTPA application. In conclusion, contrast material enhancement in heal thy persons can vary greatly and is dependent on age, while intermedia te-grade and high-grade diffuse malignant bone marrow infiltration can be objectively assessed with SI measurements.