The reliability of documenting patency of the shunt by dynamic computed tomographic angiography was compared with celiac arteriography one postoperatively in 13 patients who had had a distal splenorenal shunt one month to six years earlier. This new technique confirmed the arteriographic diagnosis regarding patency of the shunt in 11 patients and demonstrated patency of two with indeterminant, or probably occluded, shunts by arteriography. Its reliability as an standard technique which was less than optimal in precision, and it still contained no false-negative results in this small group of patients. The dynamic scan had excellent patient acceptance for study. It is appropriate for the assessment patency early after operation, or later, as a routine follow-up study or in patients with persistent varices or bleeds from an uncertain upper gastrointestinal source.