Multichannel phased array coil

All MRI examinations were performed on 3-Tesla MRI systems (GE Healthcare, WI, USA) using a multichannel phased-array coil and an endorectal coil. The MRI acquisition protocol included T2-weighted imaging (T2WI) in axial, coronal and sagittal planes (fast-spin echo sequences, TR/TE 2500–7700/83.3–143.5 ms; section thickness, 3–4 mm; intersection gap, 0–1 mm; field of view, 14–24 cm; and matrix, 288×288 to 448×224), diffusion-weighted MRI with b-values of 0 and 1000 s/mm² (single-shot spin-echo EPI sequence; TR/TE 3500–5600/70.3–105.6 ms; slice thickness: 3 mm, no interslice gap; field of view: 14–24 cm; matrix: 128×128), and a T1-weighted dynamic contrast-enhanced sequence (TR/TE=3.6–4.9/1.3–1.7 ms; slice thickness: 5 mm, no interslice gap; field of view: 24×24 cm; matrix: 256× 128–160, mean temporal resolution: 10 s). Parametric ADC maps were generated from diffusion-weighted images on a voxel-wise basis using a monoexponential model. For DCE-MRI, gadopentetate dimeglumine (Magnevist; Berlex Laboratories, Montville, NJ, USA) was administered (0.1 mmol of per kilogram of body weight at a rate of 2 mL/s) using an automatic injector (Medrad, Indianola, IA, USA).

We identified 7 consecutive patients who underwent HIFU hemiablation, follow-up contrast-enhanced TRUS evaluations, and a 12-month prostate biopsy from our Institutional Review Board–approved database. High-intensity focused US hemiablation was defined as HIFU ablation of the prostate lobe harboring prostate cancer and was performed with either Ablatherm (EDAP TMS, Vaulx-en-Velin, France) or SonaCare (SonaCare Medical, Charlotte, NC) technology. Multiparametric magnetic resonance imaging (MRI) examinations were performed on a 3-T MRI system (GE Healthcare, Milwaukee, WI) using a multichannel phased-array coil. The MRI acquisition protocol included high resolution T2-weighted, diffusion-weighted, and T1-weighted dynamic contrast-enhanced sequences. Parametric apparent diffusion coefficient (ADC) maps were calculated from the diffusion-weighted images. Multiparametric MRI was performed as part of our routine MRI/TRUS fusion-guided prostate biopsy program.^{7 (link)} Prostate cancer (prostate cancer) was assessed with the American Joint Committee on Cancer Staging Manual, seventh edition, and International Society of Urological Pathology standards. Clinically significant prostate cancer was defined as Gleason grade group 2 or higher (Gleason score ≥ 3 + 4). Clinically insignificant prostate cancer was defined as Gleason grade group 1 (Gleason score 6).^{8 (link)}