ADC maps of 43 PZ lesions 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-array 32 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 of interest (ROI) within areas of visually low signal on ADC maps; at least 50% of the lesion area was included,
avoiding the edges.
All patients underwent free-hand transperineal MRI/US fusion-guided targeted biopsy.
Fig. 1: 74-year old man with a serum PSA of 11 ng/ml, 1,5 T mpMRI. Axial T2-weighted image (a) shows a left mid-gland PZpm circumscribed hypointense lesion. The lesion has markedly high signal intensity on DWI at b-2000 (b) and markedly low signal intensity on corresponding ADC map (c). DCE-MRI assessment (d) with time/intensity curve (e) shows high peak enhancement of the lesion, earlier than adjacent normal prostate tissue, and relatively rapid wash-out. Overall PI-RADSv2 score for this lesion is 4 (DWI: 4; T2: 4; DCE +). (f) Sagittal T2-weighted image used as reference sequence for transperineal biopsy.
Fig. 2: ADC map with ROI placement within left PZpm mid-gland lesion showing ADC value of 6×10x10-6×mm2/s.
Fig. 3: Free-hand transperineal fusion-guided targeted biopsy of left PZpm PI-RADSv2 4 lesion. Histopathological evaluation of the biopsy specimens revealed a GS of 7 (3+4).
The study population was divided in two groups based on the presence (Group A) or absence (Group B) of prostate cancer in the histopathological examination of the biopsy specimens.
Differences in ADC values among group A and B were established using unpaired samples t-test.