CT findings and outcomes of acute cholecystitis: is additional ultrasound necessary?

Computed tomography versus ultrasound for the diagnosis of acute cholecystitis: a systematic review and meta-analysis

OBJECTIVES

Some patients undergo both computed tomography (CT) and ultrasound (US) sequentially as part of the same evaluation for acute cholecystitis (AC). Our goal was to perform a systematic review and meta-analysis comparing the diagnostic performance of US and CT in the diagnosis of AC.

MATERIALS AND METHODS

Databases were searched for relevant published studies through November 2023. The primary objective was to compare the head-to-head performance of US and CT using surgical intervention or clinical follow-up as the reference standard. For the secondary analysis, all individual US and CT studies were analyzed. The pooled sensitivities, specificities, and areas under the curve (AUCs) were determined along with 95% confidence intervals (CIs). The prevalence of imaging findings was also evaluated.

RESULTS

Sixty-four studies met the inclusion criteria. In the primary analysis of head-to-head studies (n = 5), CT had a pooled sensitivity of 83.9% (95% CI, 78.4-88.2%) versus 79.0% (95% CI, 68.8-86.6%) of US (p = 0.44). The pooled specificity of CT was 94% (95% CI, 82.0-98.0%) versus 93.6% (95% CI, 79.4-98.2%) of US (p = 0.85). The concordance of positive or negative test between both modalities was 82.3% (95% CI, 72.1-89.4%). US and CT led to a positive change in management in only 4 to 8% of cases, respectively, when ordered sequentially after the other test.

CONCLUSION

The diagnostic performance of CT is comparable to US for the diagnosis of acute cholecystitis, with a high rate of concordance between the two modalities.

CLINICAL RELEVANCE STATEMENT

A subsequent US after a positive or negative CT for suspected acute cholecystitis may be unnecessary in most cases.

KEY POINTS

When there is clinical suspicion of acute cholecystitis, patients will often undergo both CT and US. CT has similar sensitivity and specificity compared to US for the diagnosis of acute cholecystitis. The concordance rate between CT and US for the diagnosis of acute cholecystitis is 82.3%.

Accuracy of Ultrasound and Computed Tomography in Diagnosing Acute Cholecystitis Patients in a Tertiary Care Center in Saudi Arabia

Background Acute cholecystitis (AC) is a gallbladder inflammatory disease often associated with gallbladder stones. It accounts for up to 5% of emergency department visits. The majority of patients present with pain in the right upper quadrant, Murphy's sign, and fever. Furthermore, Saudi Arabia has been noted to have a significant prevalence of AC. According to the 2018 Tokyo Guidelines, imaging is an essential element, combined with local and systemic evidence of inflammation, for a confirmed diagnosis of AC. The definitive therapy is conducted surgically by cholecystectomy either urgently or electively. However, there are insufficient studies that focus on the accuracy of imaging in diagnosing AC patients in Saudi Arabia. Objective The aim of this study is to assess the accuracy of ultrasound (US) versus computed tomography (CT) in diagnosing AC patients at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. Methods and material A retrospective record review was conducted at KAUH during the period of June to July 2022. The study included 192 patients diagnosed with AC in the emergency department or outpatient department by US or CT or both and confirmed by laparoscopic cholecystectomy and histopathology between 2016 and 2022. Results The most common modality used was US (79.7%), followed by both US and contrast CT (10.9%). For CT, sensitivity was 81.3%, specificity was 62.5%, positive predictive value (PPV) was 59.1%, and negative predictive value (NPV) was 83.3%. For US, sensitivity was 37.9%, specificity was 81.7%, PPV was 50%, and NPV was 73.1%. A significant relationship was observed between both genders and high use of US (P = 0.0001). Conclusion We found that CT is more sensitive than US, while US is more specific in diagnosing AC.

The gallbladder: what's new in 2022?

This review focuses mainly on the imaging diagnosis, treatment, and complications of acute cholecystitis which is the most common benign disease of the gallbladder. The American College of Radiology appropriateness criteria for the imaging evaluation of patients with right upper quadrant pain and the Tokyo Guidelines for evaluating patients with acute cholecystitis and acute cholangitis are presented. The recent articles for using US, CT, MR, and HIDA in the evaluation of patients with suspected acute cholecystitis are reviewed in detail. The clinical management and postoperative complications are described. Because gallbladder polyps and adenomyomatosis can mimic gallbladder malignancies and acute cholecystitis, their imaging findings and management are presented. Finally, due the recent literature reporting better results with CT than US in the diagnosis of acute cholecystitis, a suggested approach for imaging patients with right upper quadrant pain and possible acute cholecystitis is presented in an addendum.