Peer-reviewed veterinary case report
Evaluation of interoperator variance in shunt fraction calculation after transcolonic scintigraphy for diagnosis of portosystemic shunts in dogs and cats.
- Journal:
- Journal of the American Veterinary Medical Association
- Year:
- 2001
- Authors:
- Samii, V F et al.
- Affiliation:
- Department of Surgical Sciences · United States
Plain-English summary
This study looked at how consistently different radiologists calculated the shunt fraction, which helps diagnose portosystemic shunts in dogs and cats. They reviewed the results of 101 imaging studies without knowing any details about the animals. The radiologists mostly agreed on whether the results were positive or negative, but there was a lot of variation in the actual shunt fraction numbers, especially when the results were positive. This inconsistency could be important when checking on pets after a procedure to fix a shunt. Overall, the findings suggest that different operators may not produce the same shunt fraction results, which could affect treatment decisions.
Abstract
OBJECTIVE: To determine interoperator variance in shunt fraction calculation. DESIGN: Case series. SAMPLE POPULATION: 101 transrectal portoscintigraphic studies. PROCEDURE: Results of dynamic portoscintigraphic studies were reviewed by 4 radiologists without knowledge of signalment, history, or medical profile. Results were judged to be negative or positive on the basis of the dynamic scan. Composite images were formulated, and hand-drawn regions of interest were determined for the heart and liver. Time-activity curves were generated, time-zero points were selected, curves were integrated during a 10-second interval, and shunt fractions were calculated. RESULTS: Radiologists were in agreement regarding positive versus negative results for 99 of 101 studies. Interoperator variance in shunt fraction calculation ranged from 0.4 to 59.6%. For 51 studies with positive results, variance ranged from 2.5 to 59.6% (mean +/- SD, 22.8 +/- 14.5%); differences among reviewers were significant. For 48 studies with negative results, variance in shunt fraction ranged from 0.4 to 25.9% (mean, 5.3 +/- 5.8%); significant differences among reviewers were not detected. Shunt fraction calculations were not exactly reproducible among radiologists in 94 and 100% of studies with negative or positive results, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: 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.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/11318362/