Sonographic evaluation of experimental acute renal arterial occlusion in dogs.

Eleven segmental and eight total renal artery occlusions were evaluated by sonography in transplanted kidneys of 19 adult mongrel dogs. The segmental occlusions were serially scanned daily or every other day for up to 35 days. The total occlusions were scanned daily for up to 10 days. Each occlusion was confirmed angiographically, and kidneys were examined pathologically. Acute segmental renal artery occlusion produces a sequence of sonographic changes, beginning with a focal hypoechoic mass at 24 hr, which stays unchanged for 5-7 days. At 7 days, internal echoes appear, and the infarct slowly consolidates to an echogenic, slightly depressed focus at 17 days. Total renal artery occlusion produced no appreciable change in cortical echogenicity and only slight increase in size. Acute segmental renal infarction can be detected early in its course and demonstrates a sequence of changes that may aid in dating the infarct. Total renal infarction may appear normal sonographically, and further studies are needed to confirm that diagnosis.