Evaluation of interoperator variance in shunt fraction calculation after transcolonic scintigraphy for diagnosis of portosystemic shunts in dogs and cats

Abstract

Results suggest that shunt fraction values are not reproducible among operators. Range in variability was greater in studies with positive results. This factor may be of particular clinical importance in reassessment of patients after incomplete shunt ligation.

Evaluation of ameroid ring constrictors for the management of single extrahepatic portosystemic shunts in cats: 23 cases (1996–2001)

“…46 However, there is poor reproducibility in shunt fraction determination between operators. 45 Long-term clinical outcome is the principal method for evaluating the outcome of PSS surgery. In our study, two thirds of cats (14 of 21) had portal scintigraphy 8 to 10 weeks after surgery, and 57% (8 of 14) had persistent portosystemic shunting.…”

“…Transcolonic portal scintigraphy is a sensitive and specific method for determining the presence or absence of portosystemic shunting. 25,45 Shunt fraction can be calculated from the nuclear scan, and comparison of pre-and postoperative shunt fraction has been used as a method of evaluating the outcome of surgery in cats with PSS. 46 However, there is poor reproducibility in shunt fraction determination between operators.…”

Comparison of99mTcO4−Trans‐Splenic Portal Scintigraphy with Per‐Rectal Portal Scintigraphy for Diagnosis of Portosystemic Shunts in Dogs

“…Presence of shunting can be determined from PRPS; however, visualization of the portal system is typically not achieved 20 . PRPS cannot be used to distinguish between CPSS and multiple‐acquired shunts 18–20,21 . The 2 main reasons for poor quality or non‐diagnostic studies are poor transmucosal absorption secondary to inappropriate colonic preparation and variable absorption rates among animals.…”

Trans‐splenic Portal Scintigraphy in Normal Dogs

“…The accuracy of interpretation is dependent on the quality of the study. Reasons for a poor or nondiagnostic study include: administration of an inadequate dose of radionuclide, administered radioactivity deposited in the colon proximal to the level of the shunt, or poor absorption of the radionuclide 5,6,8,9,11 . Furthermore, excessive background activity from the radionuclide in the colon can create a “bloom” effect making it difficult to see the lower count pixels of the heart and liver.…”