Is Hepatoiminodiacetic Acid Scan a Better Imaging Modality Than Abdominal Ultrasound for Diagnosing Gallbladder Disease?

Abstract

Introduction: Hepatoiminodiacetic acid (HIDA) scan is a nuclear imaging modality used to determine the health of gallbladder. Several studies have suggested using HIDA scan to diagnose hepaobiliary pathology; however, and it is not clear whether the results will lead to any changes in patients’ management. The aim of the study is to evaluate how HIDA scans are being utilized and how often the results of this study change the patient management with a definitive intervention, such as cholecystectomy and how often other imaging modalities were being ordered concomitantly with HIDA scan. Methods: Retrospective cohort study of patients who had HIDA scan between 10/1/2008 and 12/31/2012. Data was obtained from electronic medical records of patients from a single VA medical center. Data included age, sex, ordering specialist, indications, HIDA result, imaging modalities before HIDA, any intervention if HIDA result was abnormal, pathology and follow up outcomes up to 2 years. Results: 222 total patients were included in the study, with a mean age 57, mean BMI of 29, and 84.7% (188) males. A total of 171 had no gallbladder disease (GBDz) and 22.9% (51) had GBDz on pathologic examination. A false positive HIDA was seen in 39.2% (67/171), while 25.5% (13/51) had a false negative HIDA. 174 patients had ultrasound (US) done before HIDA, 133 of whom had no GBDz, while 41 had GBDz. There were 35.3% (47/133) who had a false positive US, and 46.6% (19/41) had a false negative US. Conclusion: HIDA scan is overutilized and it is increasing the cost to the patient in addition to the radiation exposure. In our study 174 patients had US done before the HIDA, and inappropriately ordering HIDA had substantial medical cost, radiation risk and possible a delay in management.