Fc 770

MpMRI of the prostate was performed on a 3T MR scanner (Achieva-TX, Philips Healthcare; Best, NL) using the anterior half of a 32-channel SENSE cardiac coil (Invivo; Gainesville FL, USA) and an endorectal coil (BPX-30, Medrad; Indianola PA, USA). No pre-examination bowel preparation was required. The balloon of each endorectal coil was distended with approximately 45 mL of perfluorocarbon (Fluorinert FC-770, 3M; St Paul MN, USA) to reduce imaging artifacts related to air-induced susceptibility.
MpMRI of prostate consisted of high resolution T2 weighted (T2W) images in 3 orthogonal planes, axial DWI, axial high b-value DWI, MR spectroscopic images and dynamic contrast enhanced MR images. Parameters for the DWI acquired at our center as part of the mpMRI (referred to as regular b-value DWI) and high b-value DWI (referred to as acquired high b-value DWI) sequences are presented in Table 1. Imaging parameters of the two DW MRI sequences were chosen to have the same echo times to avoid any bias arising from probing different compartments of diffusion with different T2 values. The acquisition times to generate a regular b-value DWI and high b value DWI vs. regular b-value DWI with calculated high b-value DWI at b=1000 and 2000s/mm² images were 8 min 31 sec vs. 4 min 47 sec (Table 1).

All animals were euthanized and perfusion fixed using phosphate buffered saline (PBS) with 4% paraformaldehyde (PFA). Kidneys were then excised and stored in 4% PFA for weeks. Prior to imaging, each kidney was washed in PBS for 24 hrs to improve MRI signal by removal of excess fixative. For imaging, the kidney was placed in a tube with fluorinert (FC-770, 3M) in a manner so that the sample could not move. Imaging was performed on a Bruker Biospec 9.4 T animal system equipped with the Bruker BGA12S-HP gradients (660 mT/m) and a bore-mounted 15 mm quadrature coil (Bruker Biospin).