Prostate Cancer Evaluated with Ferumoxtran-10–enhanced T2*-weighted MR Imaging at 1.5 and 3.0 T: Early Experience

Abstract

To prospectively evaluate the feasibility of ferumoxtran-10-enhanced magnetic resonance (MR) imaging at high magnetic field strength (3.0 T) and to compare image quality between 1.5- and 3.0-T MR imaging in terms of lymph node detection in patients with prostate cancer. This study was institutional review board approved, and all patients gave written informed consent. Forty-eight consecutive patients aged 51-79 years (mean, 65.5 years) with prostate cancer were enrolled. T2*-weighted 1.5- and 3.0-T MR images of the pelvis were acquired in a sagittal plane parallel to the psoas muscle 24 hours after ferumoxtran-10 administration. A pelvic and body phased-array coil was used and yielded an in-plane resolution of 0.56 x 0.56 x 3.00 mm at 1.5 T and 0.50 x 0.50 x 2.50 mm at 3.0 T. All images were evaluated by three readers for total image quality, lymph node border delineation, muscle-fat contrast, and vessel-fat contrast. Statistical significance was calculated by using the Mann-Whitney U test. Subsequently, the general linear mixed model was used to estimate the contributions of three factors-patient, reader, and technique-to the variability of the imaging results. Significantly (P < .05) better muscle-fat contrast, vessel-fat contrast, lymph node border delineation, and total image quality were observed at 3.0-T MR imaging. The general linear mixed model revealed that the variability of all results could be attributed to the use of 3.0-T imaging. Ferumoxtran-10-enhanced MR imaging can be performed at high magnetic field strengths and result in improved image quality, which may lead to improved detection of small positive lymph nodes.