Reply to Stephen B. Williams and John F. Ward's Letter to the Editor re: Jan P. Radtke, Constantin Schwab, Maya B. Wolf, et al. Multiparametric Magnetic Resonance Imaging (MRI) and MRI–Transrectal Ultrasound Fusion Biopsy for Index Tumor Detection: Correlation with Radical Prostatectomy Specimen. Eur Urol. In press. http://dx.doi.org/10.1016/j.eururo.2015.12.052