Determinations of prostate volume at 3-Tesla using an external phased array coil: Comparison to pathologic specimens

Rationale and Objectives. To compare techniques for measuring in vivo prostate volumes using torso phased-array imaging at 3-Tesla. Methods. Eleven patients imaged at 3-Tesla with a torso-phased array coil using multiplanar fast spin echo (FSE) T2-weighted imaging who underwent radical prostatectomy comprised the study population. Surgical specimens were imaged. The pathologic specimen volume was compared with varieties of magnetic resonance volume determinations, the latter using ellipsoid and planimetric assessments. Three-dimensional images of the excised prostate were generated. Linear correlation coefficients were calculated comparing volume determinations from image data and pathologic data. Results. Correlation coefficient (r²) values from the ellipsoid formula among six different data sets ranging between 0.325 to 0.751; the highest in vivo r² value was obtained by multiplying the anterior-posterior and the superior-inferior dimensions from the sagittal image by the right-]left dimension from the axial image. The r ² values of the planimetric volume and specimen 3-dimensional volume rendering were 0.652 and 0.86, respectively. Conclusions. Surface coil prostate imaging at 3-Tesla provides undistorted images for volume assessment and in vivo volume determinations very close to ex vivo imaging volume determinations.