Characterization of prostate cancer using T2 mapping at 3 T: A multi-scanner study

Rationale and objectives: To assess the prostate T2 value as a predictor of malignancy on two different 3 T scanners. Patients and methods: Eighty-three pre-prostatectomy multiparametric MRIs were retrospectively evaluated [67 obtained on a General Electric MRI (scanner 1) and 16 on a Philips MRI (scanner 2)]. After correlation with prostatectomy specimens, readers measured the T2 value of regions-of-interest categorized as ''cancers'', ''false positive lesions'', or ''normal tissue''. Results: On scanner 1, in PZ, cancers had significantly lower T2 values than false positive lesions (P = 0.02) and normal tissue (P = 2 x 10(-9)). Gleason >= 6 cancers had similar T2 values than false positive lesions and significantly higher T2 values than Gleason >= 7 cancers (P = 0.009). T2 values corresponding to a 25% and 75% risk of Gleason = 7 malignancy were respectively 132 ms (95% CI: 129-135 ms) and 77 ms (95% CI: 74-81 ms). In TZ, cancers had significantly lower T2 values than normal tissue (P = 0.008), but not than false positive findings. Mean T2 values measured on scanner 2 were not significantly different than those measured on scanner 1 for all tissue classes. Conclusion: All tested tissue classes had similar mean T2 values on both scanners. In PZ, the T2 value was a significant predictor of Gleason >= 7 cancers. (C) 2014 Editions francaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.