Evaluation of the CT Scan as the First Examination for the Diagnosis and Therapeutic Strategy for Acute Cholecystitis

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%.

A meta-analysis of the performance of ultrasound, hepatobiliary scintigraphy, CT and MRI in the diagnosis of acute cholecystitis

PURPOSE

To evaluate the recently reported relative diagnostic accuracy of US, CT, MRI, and cholescintigraphy for diagnosing acute cholecystitis.

METHODS

2 radiologists independently performed systematic electronic searches for articles published between 2000 and 2021 and applied inclusion/exclusion criteria. 2 different radiologists extracted data from the articles and scored each with a methodological quality tool. Pooled estimates of sensitivity and specificity were calculated with a bivariate linear mixed model. A second analysis made head-to-head comparisons (US vs. CT, US vs. cholescintigraphy). Factors were also analyzed for potential confounding effects on diagnostic accuracy.

RESULTS

Of 6121 initial titles, 22 were included. The prevalence of cholecystitis varied widely across studies (9.4-98%). Pooled sensitivity and specificity estimates were 69% (confidence limit [CL] 62-76%) and 79% (CL 71-86%) for US, 91% (CL 86-94%) and 63% (CL 51-74%) for cholescintigraphy, 78% (CL 69-84%) and 81% (CL 71-88%) for CT, and 91% (CL 78-97%) and 93% (CL 70-99%) for MRI. Regarding head-to-head comparisons, the sensitivity of CT (87.6%, CL 70-96%) was significantly higher than US (66.8%, CL 43-84%), while specificities (81.7% with CL 54-95% for US, 91.9% with CL 67-99% for CT) were similar. The sensitivity of cholescintigraphy (87.4%, CL 76-94%) was significantly greater than US (61.6%, CL 44-77%), while the specificity of US (82%, CL 65-92%) was significantly higher than cholescintigraphy (68%, CL 47-84%).

CONCLUSION

Recent data suggests that CT may have a higher sensitivity than US for diagnosing acute cholecystitis, with similar specificity. Cholescintigraphy remains a highly sensitive modality with lower specificity than previously reported. MRI remains under studied, but with promising results.

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 use of additional imaging studies after biliary point-of-care ultrasound in the emergency department

PURPOSE

We sought to determine the test characteristics of biliary point-of-care ultrasound (POCUS) and to assess the usefulness of obtaining radiology ultrasound (RUS) or cholescintigraphy (HIDA) after biliary POCUS.

METHODS

We conducted a retrospective review of emergency department patients who underwent biliary POCUS between May 4, 2018 and November 28, 2021. To be included, patients had to have at least one of the following confirmatory evaluations (considered in this order): surgery, HIDA, RUS, or abdominal CT scan. When a discrepancy existed between the POCUS and the RUS or HIDA, they were compared to a higher criterion standard (if available).

RESULTS

Using 348 patients who had a confirmatory evaluation after biliary POCUS, we found the sensitivity and specificity of biliary POCUS for gallstones to be 97.0% (95% CI 92.6 to 99.2%) and 99.5% (95% CI 97.3 to 100%), respectively. For cholecystitis, the sensitivity and specificity were 83.8% (95% CI 72.9 to 91.6%) and 98.6% (95% CI 96.4 to 99.6%), respectively. RUS and POCUS were concordant in 72 (81.8%) of 88 cases in which the patient had both studies while HIDA and POCUS were concordant in 24 (70.6%) of 34 cases. POCUS was deemed correct in at least 50% of discrepant cases with RUS and at least 30% of discrepant cases with HIDA.

CONCLUSION

Biliary POCUS has excellent sensitivity and specificity for cholelithiasis; it has lower sensitivity for cholecystitis, but the specificity remains high. Performing a confirmatory RUS or cholescintigraphy after a positive biliary POCUS adds little value, but additional imaging may be useful when POCUS is negative for cholecystitis.

Maximum Diameter of the Gallbladder Determined Presurgically Using Computed Tomography as a Risk Factor for Difficult Emergency Laparoscopic Cholecystectomy in Patients With Mild to Moderate Acute Cholecystitis

BACKGROUND

Early or emergency laparoscopic cholecystectomy (LC) was recommended in the 2018 Tokyo Guidelines for patients with mild to moderate acute cholecystitis (AC). Although surgical difficulty is frequently encountered during these surgeries, risk factors for predicting surgical difficulties have not been fully investigated, especially based on computed tomography (CT) findings.

MATERIALS AND METHODS

We investigated 72 patients who underwent emergency LC with mild (n=45) to moderate (n=27) AC. Patients who previously underwent presurgical percutaneous or endoscopic biliary drainage were excluded from this study. Difficult LC was defined using any of the following surgical factors: surgical duration ≥180 minutes, blood loss ≥300 g, or a conversion to open cholecystectomy. Subsequently, several presurgical clinical factors were analyzed, including sex, age at surgery, experience of the surgeon, interval between symptom onset and surgery, body mass index, diabetes history, presurgical white blood cell count, and C-reactive protein level. Moreover, stones in the cystic duct or perigallblader fluid and the maximum thickness and diameter of the gallbladders were evaluated via presurgical CT. Finally, logistic regression analysis was performed to compare the relationship between surgical difficulty and each clinical factor.

RESULTS

The average age at surgery of the included patients was 60.3 (range: 25 to 88 y), surgical duration was 112.2 (range: 29 to 296 min), and surgical blood loss was 55.2 (range: 0 to 530 g). Furthermore, 4 (5.6%) had to undergo open cholecystectomy, whereas postsurgical complications occurred in 5 (6.9%) patients. In addition, the mean postsurgical admission duration was 7 (range: 3 to 63 d). Thus, 12 patients experienced difficult LC, whereas 60 experienced nondifficult LC. Of the evaluated clinical factors, patients who experienced difficult LC showed higher presurgical C-reactive protein levels (10.78 vs. 6.76 mg/dL, P=0.01) and wider gallbladder diameters (48.4 vs. 41.8 mm, P<0.01) than those who experienced nondifficult LC. By univariate logistic regression analysis, results also showed that patients with a maximum gallbladder diameter had a higher risk of experiencing difficulty during emergency LC (P=0.02). Moreover, the gallbladder diameter's cutoff value was 43 mm after the receiver operating characteristic curve analysis.

CONCLUSIONS

In patients with mild to moderate AC, emergency LC can safely be performed. However, performing LC might be technically difficult in patients with AC after the identification of severe gallbladder swelling during presurgical CT.

Multidetector Computed Tomography (MDCT) Findings of Complications of Acute Cholecystitis. A Pictorial Essay

Acute cholecystitis stands out as one of the most common surgical pathologies that should always be considered in a right-upper abdominal pain emergency. For this, the importance of a correct diagnosis is well described. However, it has been demonstrated that the simple combination of clinical (pain, Murphy’s sign) and laboratory (leukocytosis) parameters alone does not provide for ruling in or ruling out the diagnosis of this condition, unless accompanied by a radiological exam. For a long time, and still today, ultrasonography (US) is by far the first-to-proceed radiologic exam to perform, thanks to its rapidity and very high sensibility and specificity for the diagnosis of simple acute cholecystitis. However, acute cholecystitis can undergo some complications that US struggles to find. In addition to that, studies suggest that multidetector computed tomography (MDCT) is superior in showing complicated forms of cholecystitis in relation to sensibility and specificity and for its capability of reformatting multiplanar (MPR) reconstructions that give a more detailed view of complications. They have shown to be useful for a precise evaluation of vascular complications, the anatomy of the biliary tree, and the extension of inflammation to surrounding structures (i.e., colitis). Therefore, based also on our experience, in patients with atypical presentation, or in cases with high suspicion for a complicated form, a MDCT abdomen scan is performed. In this review, the principal findings are listed and described to create a CT classification of acute complications based on anatomical and topographic criteria.

Hotter Than It Looks: A Retrospective Review of Patients With Cholecystitis and With Negative Imaging

INTRODUCTION

Ultrasound is the gold standard for workup of cholecystitis in the emergency department, and findings heavily influence clinical decision-making. Patients with negative imaging for acute cholecystitis may be inappropriately sent home. The purpose of our study was to review the pathology and outcomes of patients presenting with biliary pain and negative ultrasound findings of acute cholecystitis.

MATERIALS AND METHODS

Emergency department patients who underwent laparoscopic cholecystectomy between January 2015 and February 2019 were reviewed retrospectively. Only patients with negative or equivocal imaging were included. The primary outcome was the incidence of cholecystitis on final pathology.

RESULTS

Two hundred fifty-seven patients underwent laparoscopic cholecystectomy. Pathology demonstrated cholecystitis in 84% of patients. Only 15% of patients had cholelithiasis without cholecystitis on pathology. The incidence of cholecystitis was similar in negative and equivocal imaging groups (84% versus 83%; P = 0.960). The median time from admission to the operating room was 12.1 h (interquartile range 7.1-18.3 h), and hospital length of stay was 1.2 d (interquartile range 0.8-1.7 d).

CONCLUSIONS

This study found that patients with negative or equivocal imaging had cholecystitis on pathology. On review of patient outcomes, those patients who underwent surgical intervention had a low rate of complications and short hospital stay.