Multiparameter MRI assessment of normal-appearing and diseased vertebral bone marrow.

Abstract

To evaluate spin-lattice (T1) and spin-spin (T2) relaxation times as well as apparent diffusion coefficients (ADCs) of the fat and water components in the vertebral bone marrow (vBM) of patients with benign and malignant lesions. Forty-four patients were examined at 1.5 T: there were 24 osteoporotic vertebral fractures (15 women, 9 men; median age: 73, 48-86 years) and 20 malignant vertebral infiltrations (9 women, 11 men; median age: 60, 25-87). Relaxation times were determined separately for the water and the fat component using a saturation-recovery technique for T1 and measurements with variable echo times for T2. ADCs were determined with a diffusion-weighted (DW) echo-planar imaging (EPI) and a single-shot turbo-spin-echo (ssTSE) sequence. T1 of the water component and ADCs were significantly increased in the lesions compared with normal-appearing vBM (malignant: 1,252 vs. 828 ms, osteoporotic: 1,315 vs. 872 ms). ADCs determined with the DW-ssTSE were significantly increased compared with the DW-EPI. ADCs determined with the DW-ssTSE differed significantly between osteoporotic and malignant lesions (1.74 vs 1.35 x 10⁻³ mm²/s. All parameters exhibit significant differences between normal-appearing vBM and the lesions. However, only the ADCs determined with the DW-ssTSE differed significantly between osteoporotic fractures and malignant lesions, potentially allowing for a differential diagnosis of these two entities.