Which of the following is the pathognomonic ultrasound finding in acute cholecystitis?

Explanation

## Ultrasound Diagnosis of Acute Cholecystitis ### Diagnostic Criteria for Acute Cholecystitis on Ultrasound | Finding | Sensitivity | Specificity | Pathognomonic? | Notes | |---|---|---|---|---| | **Sonographic Murphy's sign** | 80–90% | **95–98%** | **YES** | Most specific single finding | | Pericholecystic fluid | 50–60% | 85% | No | Non-specific; seen in other conditions | | Thickened wall (>3 mm) | 80% | 70% | No | Can occur in cirrhosis, hepatitis, malnutrition | | Gallstones | 95% | 100% | No | Present in ~90% but not diagnostic of cholecystitis | | Dilated CBD | Variable | Low | No | Suggests obstruction, not cholecystitis alone | ### Sonographic Murphy's Sign **Key Point:** **Sonographic Murphy's sign** is the **most specific ultrasound finding** for acute cholecystitis. It is elicited by: 1. Placing the ultrasound probe directly over the gallbladder 2. Asking the patient to take a deep breath (inspiratory maneuver) 3. **Positive if the patient experiences maximal tenderness when the gallbladder is under the probe** (and the tenderness is not reproduced by palpating other areas) **High-Yield:** Sonographic Murphy's sign has a specificity of **95–98%** — the highest among all ultrasound findings in acute cholecystitis. A **positive sonographic Murphy's sign in the presence of gallstones and RUQ pain is diagnostic of acute cholecystitis**. **Clinical Pearl:** The clinical (palpation) Murphy's sign and sonographic Murphy's sign are different: - **Clinical Murphy's sign:** Palpation of RUQ during inspiration; less specific - **Sonographic Murphy's sign:** Ultrasound probe over gallbladder during inspiration; highly specific **Mnemonic:** **SMURF** = **S**onographic **M**urphy's **U**ltrasound **R**ight **F**ossa — the most specific finding for cholecystitis. ### Why Other Findings Are Not Pathognomonic - **Pericholecystic fluid:** Can occur in peritonitis, ascites, or other inflammatory conditions - **Thickened wall:** Seen in cirrhosis, congestive heart failure, hypoalbuminemia, hepatitis - **Gallstones:** Present in 10–15% of asymptomatic population; not diagnostic of disease