From the Guidelines
The sonographic Murphy sign is a moderately sensitive (81%) and specific (83%) diagnostic tool for acute calculus cholecystitis, and its significance lies in its ability to help diagnose acute inflammatory conditions of the gallbladder in real-time during ultrasonography. The sonographic Murphy sign is elicited when a patient experiences pain when the ultrasound probe is pressed directly over the gallbladder, similar to the clinical Murphy's sign but with the advantage of direct visualization of the gallbladder.
Key Points to Consider
- The reliability of the sonographic Murphy sign can be affected by several factors including patient's pain tolerance, use of analgesics prior to examination, and the examiner's technique 1.
- The sonographic Murphy sign is most useful when interpreted alongside other sonographic findings such as gallbladder wall thickening, pericholecystic fluid, and the presence of gallstones.
- In elderly patients or those with diabetes, the sign may be absent despite severe disease due to autonomic neuropathy affecting pain perception.
- For optimal diagnostic accuracy, the sonographic Murphy sign should be considered as part of a comprehensive clinical and imaging assessment rather than as a standalone indicator of gallbladder disease.
Diagnostic Performance
- The sensitivity of the sonographic Murphy sign ranges from 50 to 100% and specificity from 33 to 100% 1.
- The summary sensitivity and specificity of the sonographic Murphy sign are 81% (95% CI 75 to 87%) and 83% (95% CI 74 to 89%), respectively 1.
Limitations and Future Directions
- The diagnostic performance of the sonographic Murphy sign can be improved by using new ultrasonography criteria such as point shear-wave elastography (pSWE) or superb microvascular imaging (SMI) 1.
- However, these techniques require expertise and have limited external validity due to the small number of patients and poor reference standard.
Clinical Implications
- The sonographic Murphy sign is a valuable diagnostic tool for gallbladder disease, particularly acute cholecystitis, and should be considered as part of a comprehensive clinical and imaging assessment.
- Clinicians should be aware of the limitations and potential pitfalls of the sonographic Murphy sign and interpret the results in the context of the patient's clinical presentation and other diagnostic findings.
From the Research
Sonographic Murphy Sign Significance
- The sonographic Murphy sign is a useful adjunct in the assessment of patients with suspected acute cholecystitis 2.
- The sign is characterized by the presence of maximal tenderness elicited over a sonographically localized gallbladder.
Sensitivity and Specificity
- The sensitivity of the sonographic Murphy sign in acute cholecystitis was reported to be 63% with a specificity of 93.6% in one study 2.
- Another study found a sensitivity of 86% and a specificity of 35% for the sonographic Murphy sign in acute cholecystitis 3.
- The combination of the Murphy sign accompanied by gallstones yielded a specificity of 77% 3.
- A study using power Doppler sonography found that the sensitivity of the Murphy sign was not directly reported, but the sign was present in 96% of patients with acute cholecystitis, although it lacked specificity (71%) for diagnosing acute cholecystitis 4.
Predictive Values
- The predictive value of a positive sonographic Murphy sign was 72.5%, while the predictive value of a negative sign was 90.5% in one study 2.
- Another study found a positive predictive value of 43% and a negative predictive value of 82% for the sonographic Murphy sign in acute cholecystitis 3.