Abstract #2294

Prostate Volume in Sexually Immature and Mature Dogs as Measured by MRI

Paul J. McCracken¹, Marie Holahan¹, Stephanie Born², Sairam Bellum², Nicholas Gatto³, Donald S. Williams¹

¹Imaging Department, Merck Research Laboratories, West Point, PA, USA; ²Toxicological Sciences, Merck Research Laboratories, West Point, PA, USA; ³Pathology, Merck Research Laboratories, West Point, PA, USA

MRI may contribute to drug development is augmenting traditional histopathology and complementing histopathological evaluations. Prostate volume is of interest for comparison to pathology, therapeutic effects, or adverse effects. We evaluated MRI as a non-invasive marker of prostate volume in sexually immature dogs and sexually mature dogs, as well as prostate volume change over 4 weeks. There was a significant amount of age-related prostate volume change in 4 weeks. The comparison to ex-vivo absolute prostate weights at necropsy shows a high correlation (R2=0.916). This demonstrates that Magnetic Resonance Imaging may be used to accurately monitor prostate volume, and therefore weight.