Multiparametric Magnetic Resonance Imaging (mpMRI) has a good diagnostic accuracy in detecting clinically significant prostate cancer (csPCa), defined as Gleason Score (GS)≥3+4,with a negativepredictive value ranging from 63% to 98% [1]. Currently, mpMRI is frequently performed before prostate biopsy.According tothe 2018European Association of Urology (EAU) guidelines [2] mpMRI can either be used theoretically: - to improve the diagnosis of csPCa by performing MRI-targeted biopsies in addition to standard systematic biopsies in patients with a positive mpMRI; patients with a negative mpMRI would undergo standard systematicbiopsies;...

ADC maps of 43 PZlesions with PI-RADSv2 score 4 were retrospectively evaluated. 14/43 lesions were upgraded from 3 to 4 based on positive DCE imaging (PIRADSv2=3+1). All exams were performed using the same 1.5 T MR scanner equipped with a pelvic phased-array32 channel coil, using a multi-b DWI sequence (range 0-2000, step of 500 s/mm2). Three readers, blinded to biopsy results, obtained in consensus ADC values drawing regions ofinterest (ROI) within areas of visually low signalon ADC maps; at least 50% of the lesion area...

Fusion-targeted biopsy was positive for PCa in 28/43 lesions (Group A), 23/28 showing a Gleason Score (GS)≥3+4, with mean±SD ADC value of 715±130x10-6×mm2/s and negative in 15/43 lesions (Group B) with mean±SD ADC value of 879±67x10-6×mm2/s. T-test showed significant lower ADC values in group A compared with group B (p-value<0.01). In PI-RADSv2 4(3+1) subgroup, 5/14 suspected lesions were positive for PCa (GS≥3+4 in 3 cases), with mean±SD ADC value of 726±89x10-6×mm2/sand 9/14 lesions were negative for PCa with mean±SD ADC value of 888±58x10-6×mm2/s.

The results of our MRI scannershow that PZ lesions PIRADSv2 score 4 have greater probability to be PCa when the ADC value is lower than 715x10-6×mm2/sandto be benign when the ADC value ishigher than879x10-6×mm2/s. ADC values showed significant differences among true positive and true negative lesions, all PIRADSv2 score 4 and 3+1 at mpMRI. Thus, the quantitative evaluation of ADC maps could improve the specificity of mpMRI and it can be a promising tool, in addition to PI-RADSv2 score, for risk stratification of lesions suspected...

S. Verna1, S. Agostini1, E. Bertelli1, F. Parretti1, S. Lucarini1, F. De Nisco1, M. Mastrorosato1, L. N. Mazzoni2, V. Miele1. 1. Radiology Department, Careggi University Hospital, Florence, Italy 2. Medical Physics, USL Toscana Centro, Pistoia, Italy Email: [email protected]

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