CT Case Review: Prostatic Carcinoma

12-year-old male neutered mix breed dog that presented with a 3­month duration history of hematuria. The prostate was enlarged on rectal examination.

The prostate was moderately enlarged with patchy regions of poor contrast enhancement centrally (FIG 1). The overall shape and contour was normal. The medial iliac lymph nodes were normal shape and size. On survey CT the liver had an undulating outer contour, but no nodules were seen. On post­contrast CT images, poorly enhancing nodules (4­8mm wide) were seen in all liver lobes. The lumbar spine has very active­ appearing, speculated periosteal proliferation on the ventral aspect of the vertebral bodies from L2­L7 (FIG 2). This proliferation seemed to originate from the central portion of the bodies. No lysis was seen. A similar appearance was seen on the ventral aspect of the sacral vertebrae and both ilial wings.

Liver: metastastic neoplasia Spine: neoplastic reactive periosteal changes (or atypical metastasis) Prostate: carcinoma (or abscessation).

Staging complicated intra­abdominal lesions can be very challenging with conventional radiography and ultrasound. Each modality has their advantages, but neither, even when combined, provides the ability to provide overall high spatial resolution of all bones and intra­abdominal organs, provide contrast enhancement information (vital for assessment of nodular lesion in the liver) and high detail cross­ sectional bone detail. The Vimago™ veterinary CT scanner provided all three of these vital attributes. Because this was a large dog, the acquisition was made of three separate, sequential overlapping image acquisitions automatically spliced into one data set. No other system can provide this function with the ability to image at extremely high spatial resolutions (< 200 uM). The contrast resolution of the post­contrast images provided the basis for identifying the liver nodules (not seen on the ultrasound scan) and characterization as probably malignant.