MAGNETIZATION-TRANSFER CONTRAST MRI OF MUSCULOSKELETAL NEOPLASMS

Magnetic resonance imaging (MRI) examinations were performed in 15 pat ients with musculoskeletal neoplasms to assess the value of magnetizat ion transfer contrast in tumor characterization. Multiplanar gradient- recalled echo sequences (TR 500-600/TE 15-20/flip angle 20-30 degrees) were performed first without and then with magnetization transfer con trast generated by a zero degree binomial pulse (MPGR and MTMPGR). Sta ndard T1-weighted spin echo images (SE; TR300-400/TE 12-20) and either T2-weighted SE (TR 2000-2900/TE 70-80) or T2-weighted fast spin echo (FSE; TR 4000-5000/TE 100-119 effective) images were also obtained. Si gnal intensities on MTMPGR scans were compared to those on MPGR scans for both tumors and normal tissues. Signal intensity ratios (SIR) and contrast-to-noise ratios (CNR) were also compared for all sequences. M TMPGR images provided better contrast between pathologic tissues and m uscle than did standard MPGR images, increasing both conspicuity of le sions and definition of tumor/muscle interfaces. Benign and malignant tumors, with the exception of lipoma, underwent similar degrees of mag netization transfer and could not be distinguished by this technique.