Highlights • Objective IQ for T2WI was at 1.5T under optimized parameters comparable to 3T. • SNR and CNR of DWI were significantly higher at 3T. • Subjective IQ on was significantly better at 3T. • ...PI-RADS v2 scores were similar at 3T and 1.5T.
•Objective IQ for T2WI was at 1.5T under optimized parameters comparable to 3T.•SNR and CNR of DWI were significantly higher at 3T.•Subjective IQ on was significantly better at 3T.•PI-RADS v2 scores ...were similar at 3T and 1.5T.
This study prospectively evaluates objective image quality (IQ), subjective IQ, and PI-RADS scoring of prostate MRI at 3.0T (3T) and 1.5T (1.5T) within the same patients.
Sixty-three consecutive patients (64±9years) were prospectively included in this non-inferiority trial, powered at 80% to demonstrate a ≤10% difference in signal-to-noise (SNR) and contrast-to-noise ratio (CNR) of T2-weighted and diffusion-weighted imaging (T2WI, DWI) at 1.5T compared to 3T. Secondary endpoints were analysis of subjective IQ and PI-RADS v2 scoring.
All patients received multi-parametric prostate MRI on a 3T (T2WI, DWI, DCE) and bi-parametric MRI (T2WI, DWI) on a 1.5T scanner using body coils, respectively. SNR and CNR of T2WI were similar at 1.5T and 3T (p=0.7–1), but of DWI significantly lower at 1.5T (p<0.01). Subjective IQ was significantly better at 3T for both, T2WI and DWI (p<0.01). PI-RADS scores were comparable for both field strengths (p=0.05–1). Inter-reader agreement was excellent for subjective IQ assessment and PI-RADS scoring (k=0.9–1).
Prostate MRI at 1.5T can reveal comparable objective image quality in T2WI, but is inferior to 3T in DWI and subjective IQ. However, similar PI-RADS scoring and thus diagnostic performance seems feasible independent of the field strength even without an endorectal coil.
