Pharmacokinetic evaluation of prostate magnetic resonance imaging

Focal lesions detected on Mp-MRI can be evaluated with quantitative and semiquantitative parameters in terms of malignancy. In this study, 168 patients were examined who underwent 3 Tmp-MRI and had a suspicion of malignancy according to PI-RADS v2. Of these 168 patients, 42 patients (25%) were pathologically diagnosed after radical prostatectomy and 124 patients (73,81%) were pathologically diagnosed by biopsy. Two patients were diagnosed definitively by follow-up imaging. We investigated whether the ADC value and pharmacokinetic parameters obtained from DCE-MRI could predict the pathological character of the lesion and the pathological grade of those with cancer (ISUP grade). The lesions were PIRADS 3 in 6 patients, PIRADS 4 in 97 patients and PIRADS 5 in 65 patients according to PIRADS v2. The success of the parameters were calculated by ROC analysis, area and volume under the curve. The best cut-off points were examined by ROC curves and variance analysis, and the test combination that could make the best discrimination was examined by logistic regression and discriminant analysis. ADC, Ve, and TTP values were significantly lower in cancers; Ktrans, Kep and Vp values were significantly lower in benign conditions and each parameter showed high diagnostic accuracy in malignant - benign differentiation. When the best cut-off points of the parameters were taken into consideration, the best combination to differenciate the triple-group was ADC, TTP and Ve, and the diagnostic success of this combination for cancer was 84.9%. The best combination to differenciate benign - malign was ADC, TTP and volume, and the diagnostic success of this combination for cancer was %88,4 with PPD 86,36% and NPD 83,87%. As the ADC value decreased in the cancer group, the ISUP grade showed a statistically significant increase. In conclusion, the analysis of DCE-MRI data can be done with simple visual or semiquantitative and quantitative approaches. The ADC value, DCE-MRI and pharmacokinetic parameters may facilitate diagnosis of prostate cancer by adding functional information to anatomical information provided by conventional MRI sequences.