Computed intensity correction of MR images of the prostate gland obtained with an intrarectal surface coil

MR images of the prostate gland are obtained using a surface coil wrapped around the balloon of a barium enema cannula. If the wire loop is attached to a narrow-bore tubing filled with baby oil, the shape and position of the coil can be accurately constructed in three dimensions. The Blot-Savart law is used to calculate the exact sensitivity of the reconstructed coil throughout the imaging space. The values obtained are then used to correct the gain of each pixel. No phantom images, with their concomitant registration problems, are needed. Dramatic improvements in contrast, signal-to-noise ratio, and resolution are achieved