[A comparison of magnetic resonance spectroscopy and diffusion weighted imaging for diagnosing prostate cancer]

To compare the clinical values of magnetic resonance spectroscopy (MRS) and diffusion weighted imaging (DWI) in diagnosing prostate cancer.

A 1. 5T MR scanner was used in this study. We measured 274 regions of interest (ROI) in the images produced by MRS and DWI from 53 patients. The biopsy confirmed 150 ROI as cancers and 124 ROI as non-cancers. The results of MRS and DWI were compared using receiver operating characteristic (ROC) curves.

Significant differences (P<0. 05) between malignant and benign tumors were found in signal intensity (b= 0,100,800 s/mm, in DWI), ADC value(in DWI), Cit content integral, Cho content integral and (Cho+Cr)/Cit ratio (in MRS). The ROC curves showed that ADC value, signal intensity (b=800 s/mm2) and the ratio of (Cho+Cr)/Cit performed better in distinguishing prostate cancers from benign tumors. The optimal operating point (OOP) of ADC value was determined as 1. 027 x 10(-3) mm2/s, with 0. 887 specificity, 0. 953 sensitivity, 0. 84 Youden index, and the area under curve (AUC) of 0. 966. The OOP of signal intensity (b=800 s/mm2) was determined as 47. 1, with 0. 806 specificity, 0. 72 sensitivity, 0. 53 Youden index, and the AUC of 0.782; The OOP of (Cho+Cr)/Cit ratio was determined as 0.78, with 0. 806 specificity, 0. 793 sensitivity, 0. 60 Youden index, and the AUC of 0. 844.

DWI is a better method than MRS in differentiating prostate cancers from benign tumors.