MR EVALUATION OF VERTEBRAL METASTASES - T1-WEIGHTED, SHORT-INVERSION-TIME INVERSION-RECOVERY, FAST SPIN-ECHO, AND INVERSION-RECOVERY FAST SPIN-ECHO SEQUENCES

PURPOSE: To compare the detectability of vertebral metastatic disease on T1-weighted, short-inversion-time inversion recovery (STIR), fast s pin-echo (FSE), fat-saturated FSE, and inversion recovery FSE (IRFSE) MR sequences using percent contrast and contrast-to-noise ratios. METH ODS: Patients with proved metastatic disease underwent imaging on a 1. 5-T MR system with sagittal T1-weighted (800/20/2 [repetition time/ech o time/excitations]) (91 patients), STIR (1400/ 43/2; inversion time, 140) (98 patients), FSE (4000/180/2) (46 patients), fat-saturated FSE (4000/180/2) (16 patients), and IRFSE (29 patients) sequences. Percent contrast and contrast-to-noise ratio were calculated for the lesions. The number of metastatic lesions detected with each of the pulse sequ ences was also calculated. RESULTS: Mean percent contrast was, for T1- weighted sequence, -42.2 +/- 1%; STIR, 262 +/- 34%; FSE, 121 +/- 21%; fat-saturated FSE, 182 +/- 6%; and IRFSE, 272 +/- 47%. The mean contra st-to-noise ratio for T1-weighted was -4.63 +/- 1.7; STIR, 10.8 +/- .9 8; FSE, 4.16 +/- .76; fat-saturated FSE, 4.87 +/- .19; and IRFSE, 5.2 +/- .87. STIR and IRFSE showed the highest number of lesions, followed by T1-weighted, fat-saturated FSE, and FSE sequences. T1-weighted seq uences showed 94%, FSE 55%, and fat-saturated FSE 78% of the lesions d etected. Epidural metastatic lesions were better depicted on T1-weight ed, FSE, and fat-saturated FSE sequences. CONCLUSION: STIR was superio r to both T1-weighted and FSE (with and without fat saturation) for de tection of metastatic lesions, in terms of both percent contrast and c ontrast-to-noise ratio and visibility. IRFSE was equal to STIR for the detection of metastasis by both subjective and objective criteria. T1 -weighted, FSE, and fat-saturated FSE sequences were superior to STIR and IRFSE in the detection of epidural metastatic disease. IRFSE provi ded faster scanning time, which could be translated into greater resol ution.