Multiparametric MRI of the prostate at 3 T: limited value of 3D (1)H-MR spectroscopy as a fourth parameter.

ABSTRACT

PURPOSE: The aim of our study was to assess whether multiparametric magnetic resonance imaging (MP-MRI) of the prostate with three parameters (PS3 T2-weighted, DWI, and DCE) benefits from an additional fourth parameter (PS4 including (1)H-MRSI) in the detection and grading of prostate cancer (PCa) at 3 T. METHODS: MP-MRI was performed in 64 patients (mean 66.7 years, mean PSA 13 ng/ml). Reference standard was obtained by histopathology. Two readers independently evaluated the images. A summation score of each individual parameter for three parameters (PS3) and for four parameters (PS4) was calculated. RESULTS: In 52 (81.3 %) of 64 patients, histopathology confirmed a PCa. The diagnostic performance for PCa detection of PS4 (O1 91.7 %, O2 91.3 %) equaled that of PS3 (O1 92.8 %, O2 92.2 %, P > 0.05). Prediction of high-grade PCa by PS4 (O1 75.1 %, O2 74.7 %) was as good as with PS3 (O1 75.1 %, O2 72.8 %, P > 0.05). Kappa agreement between the two readers was substantial (0.734 PS4) to moderate (0.558 PS3). CONCLUSIONS: MP-MRI with four parameters including (1)H-MRSI does not increase the detection and grading of prostate cancer at 3 T compared to MP-MRI with three parameters. A sum score accurately detects PCa at 3 T without an endorectal coil and shows potential for the prediction of tumor grade.