Detection of prostate cancer: Utility of diffusion-weighted MR imaging and 3D MR spectroscopic imaging

Abstract Purpose To prospectively compare the mean ADC generated from DWI, the mean choline + creatine/citrate ratio generated from 3D MRS and the combined mean ADC and mean choline + creatine/citrate ratio in the detection of prostate cancer, and to correlate between the choline + creatine/citrate ratio and the aggressiveness of malignancy determined by Gleason score, with histopathological examination of the excised gland as the reference standard. Patients and methods Forty-six patients with biopsy-proved cancer underwent pre-operative MRI at 1.5 T. Axial T 1, axial, coronal and sagittal T 2-weighted, diffusion-weighted and 3D MRS using a point-resolved spectroscopic sequence (PRESS) were acquired. The mean ADC, mean choline + creatine/citrate ratio and combined parameters for malignant lesions are correlated with the pathological results. For each malignant lesion choline + creatine/citrate ratio was correlated with the aggressiveness of malignancy determined by Gleason score. Receiver operating characteristic (ROC) curves were used to determine sensitivity, and specificity of the studied parameters, and Kappa measures of agreement were calculated for prostate cancer detection. Results The mean ADC for tumor tissue was 1.0 ± 0.22 × 10 −3  mm 2 /s (mean ± SD), and was significantly lower than that for non-tumor tissue 1.44 ± 0.28 × 10 −3  mm 2 /s ( p p p p Conclusion The combination of ADC and (choline + creatine)/citrate ratio is better than each parameter alone in differentiating between tumor and non-tumor prostatic tissue, also MR spectroscopic imaging findings of prostate tumor (Cho + Cr)/Cit ratio correlate with pathologic Gleason score. The combined parameters offer a promising non-invasive method for the diagnostic workup of prostate cancer.