Adrenal masses in patients with malignancy: prospective comparison of echo-planar, fast spin-echo, and chemical shift MR imaging.

Overview

PURPOSE: To assess echo-planar, fast spin-echo (SE), and chemical shift magnetic resonance (MR) imaging in differentiation of adrenal adenomas from malignant adrenal masses in patients with known malignancy. MATERIALS AND METHODS: Sixty-eight adrenal masses (23 malignant, 45 benign) in 68 patients with known malignancy were examined with echo-planar, fast SE with and without fat suppression, and chemical shift pulse sequences. RESULTS: With a cutoff T2 value of 75 msec, the sensitivity of echo-planar imaging for benign lesions was 82%, and specificity was 96%. With a cutoff adrenal mass-to-spleen signal intensity ratio of 0.80, the sensitivity of fast SE imaging for benign lesions was 53%, and specificity was 96%. With a cutoff adrenal mass-to-spleen ratio of 0.55, the sensitivity of chemical shift imaging for benign lesions was 80], and specificity was 100%. CONCLUSION: Chemical shift imaging and calculated T2 values from echo-planar imaging are promising techniques for differentiation of adrenal adenomas from malignant adrenal masses and can obviate biopsy.