Rapid quantitative T<sub>2</sub> mapping of the prostate using three-dimensional dual echo steady state MRI at 3T.

Overview

PURPOSE: To develop and evaluate a rapid three-dimensional (3D) quantitative T₂ mapping method for prostate cancer imaging using dual echo steady state (DESS) MRI at 3T. METHODS: In simulations, DESS-T₂ mapping in the presence of T₁ and B1+ variations was evaluated. In a phantom and in healthy volunteers (n = 4), 3D DESS-T₂ mapping was compared with a two-dimensional turbo spin echo (TSE) approach. In volunteers and a pilot patient study (n = 29), quantitative T₂ in normal prostate anatomical zones and in suspected cancerous lesions was evaluated. RESULTS: The simulated bias for DESS-T₂ was < 2% (5%) for typically observed T₁ ( B1+) variations. In phantoms and in vivo, high correlation of DESS-T₂ and TSE-T₂ (r² = 0.98 and 0.88, P < 0.001) was found. DESS-T₂ in the normal peripheral zone and transition zone was 115 ± 26 ms and 64 ± 7 ms, respectively, in healthy volunteers and 129 ± 39 ms and 83 ± 12 ms, respectively, in patients. In suspected cancerous lesions, DESS-T₂ was 72 ± 14 ms, which was significantly decreased from the normal peripheral zone (P < 0.001) but not from the transition zone. CONCLUSION: Rapid 3D T₂ mapping in the entire prostate can be performed in 1 min using DESS MRI. Magn Reson Med 76:1720-1729, 2016. © 2016 International Society for Magnetic Resonance in Medicine.