What is the significance of non-opacification of the gallbladder on a Hepatobiliary Iminodiacetic Acid (HIDA) scan with normal bile ducts?

From the Guidelines

Nonopacification of the gallbladder on a HIDA scan with normal bile ducts is highly suggestive of cystic duct obstruction, most commonly due to gallstones, and indicates acute cholecystitis. This finding represents a functional blockage preventing the radiotracer from entering the gallbladder while still allowing it to flow through the common bile duct into the intestine. When evaluating patients with right upper quadrant pain, this pattern strongly supports surgical intervention, typically laparoscopic cholecystectomy, as the appropriate treatment, as suggested by the 2020 world society of emergency surgery updated guidelines for the diagnosis and treatment of acute calculus cholecystitis 1. While waiting for surgery, patients should receive supportive care including IV fluids, pain management with medications, and antibiotics if infection is suspected. The pathophysiology involves inflammation of the gallbladder wall following obstruction, which impairs normal filling and emptying functions. Other less common causes of nonopacification include chronic cholecystitis, gallbladder dyskinesia, or rarely, gallbladder agenesis. It's essential to correlate these findings with clinical symptoms and other imaging studies for definitive diagnosis and management planning, considering the recommendations from the 2024 clinical practice guideline update by the infectious diseases society of America on complicated intraabdominal infections 1. Key points to consider in the diagnosis and management of acute cholecystitis include:

• Clinical signs and symptoms, such as right upper quadrant pain, fever, and jaundice
• Laboratory findings, including indicators of inflammation and biliary stasis
• Imaging findings, such as nonopacification of the gallbladder on HIDA scan or biliary dilatation on CT
• The role of CT with IV contrast in evaluating suspected complications of acute cholecystitis or acute cholangitis 1. In clinical practice, the utilization of HIDA scans may be limited due to required resources and time, but they remain a valuable diagnostic tool in certain situations, as noted in the 2020 world society of emergency surgery updated guidelines 1.

From the Research

Significance of Non-Opacification of the Gallbladder on a HIDA Scan

• Non-opacification of the gallbladder on a Hepatobiliary Iminodiacetic Acid (HIDA) scan can indicate acute cholecystitis, even with normal bile ducts 2, 3, 4, 5.
• The HIDA scan is a sensitive test for diagnosing acute cholecystitis, with a sensitivity of 86% compared to ultrasonography (US) which has a sensitivity of 48% 5.
• A normal HIDA scan with non-opacification of the gallbladder can also be seen in patients with biliary dyskinesia or low gallbladder ejection fraction (EF) 6.
• In some cases, non-opacification of the gallbladder on a HIDA scan can be an indication for cholecystectomy, especially in patients with biliary colic and hyperkinetic gallbladder 6.

Diagnostic Criteria

• The diagnosis of acute cholecystitis can be established using ultrasonography (US), cholecystoscintigraphy (HIDA), or both 3, 4, 5.
• The HIDA scan is considered the investigation of choice for suspected acute gallbladder disease, especially when the diagnosis is uncertain 3.
• A thorough work-up, including laboratory results and physical exam findings, can be effective in diagnosing acute cholecystitis, even in cases with atypical presentations 2.

Clinical Implications

• Non-opacification of the gallbladder on a HIDA scan with normal bile ducts can have significant clinical implications, including the need for further evaluation and potential cholecystectomy 2, 3, 4, 5, 6.
• The HIDA scan can provide valuable information about gallbladder function and can help guide treatment decisions in patients with suspected acute cholecystitis or biliary dyskinesia 5, 6.