Combined prostate diffusion tensor imaging and dynamic contrast enhanced MRI at 3T--quantitative correlation with biopsy.

Abstract

The purpose of this work was to compare diagnostic accuracy of Diffusion Tensor Imaging (DTI), dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) and their combination in diagnosing prostate cancer. Twenty-five patients with clinical suspicion of prostate cancer underwent MRI, prior to transrectal ultrasound-guided biopsies. MRI data were correlated to biopsy results. Logistic regression models were constructed for the DTI parameters, DCE MRI parameters, and their combination. The areas under the receiver operator characteristic curves (AUC) were compared between the models. The nonparametric Wilcoxon signed rank test was used for statistical analysis. The sensitivity and specificity values were respectively 81% (74-87%) and 85% (79-90%) for DTI and 63% (55-70%) and 90% (85-94%) for DCE. The combination "DTI or DCE MRI" had 100% (97-100%) sensitivity and 77% (69-83%) specificity, while "DTI and DCE MRI" had 44% (37-52%) sensitivity and 98% (94-100%) specificity. The AUC for DTI+DCE parameters was significantly higher than that for either DTI (0.96 vs. 0.92, P=.0143) or DCE MRI parameters (0.96 vs. 0.87, P=.00187) alone. In conclusion, the combination of DTI and DCE MRI has significantly better accuracy in prostate cancer diagnosis than either technique alone.