Diagnosis of acute cholecystitis: why do patients get multiple studies?

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.

The imaging diagnosis of cholecystitis in the adult ED: a comparative multi-reader, multivariable analysis of CT and US image features

PURPOSE

The purposes of this study are (1) to utilize multivariable logistic regression in order to evaluate which image feature combination is most predictive in the diagnosis of cholecystitis for computed tomography (CT) and ultrasound (US) in adult ED patients and (2) to use these results to compare the accuracy of CT and US.

METHODS

For RUQ pain patients undergoing US and CT at the same visit, multiple image features were evaluated independently by 2 radiologists blinded to additional data. Inter-reader variability was measured with the Kappa statistic. Sonographic Murphy's sign (SMS) information was obtained from original reports. Multivariable logistic regression was utilized to develop optimal predictive models for each modality. For US, models with/without SMS were compared to establish its relative value.

RESULTS

446 patients met inclusion criteria. For CT, the combination of cholelithiasis, short-axis gallbladder diameter > 3 cm, pericholecystic fluid or inflammation, and mural thickening > 3 mm provided the optimal model for both readers. For US, the optimal model included cholelithiasis, short-axis diameter > 3 cm, mural heterogeneity/striation, and sludge/debris for both readers. Kappa = 0.79-0.96 for included image features. For both readers, CT and US models had equivalent diagnostic performances; the SMS did not contribute significantly to US models.

CONCLUSION

For a diagnosis of cholecystitis in the ED, (1) the optimal image feature combination for CT is cholelithiasis, short-axis diameter > 3 cm, pericholecystic fluid or inflammation, mural thickening > 3 mm; and cholelithiasis, short-axis diameter > 3 cm, mural heterogeneity/striation, sludge/debris for US; (2) CT and US have equivalent diagnostic performance; (3) inter-reader reliability is substantial to excellent for utilized image features; (4) the SMS does not affect US model accuracy.

Relations between hepatobiliary scintigraphy findings and histopathological factors in patients with recurrent biliary colic

BACKGROUND/PURPOSE

The aim of the present study was to investigate the relationship between hepatobiliary scintigraphy findings and histopathological results in patients with recurrent biliary colic.

METHODS

We retrospectively enrolled 107 patients who underwent hepatobiliary scintigraphy for recurrent biliary colic and subsequent cholecystectomy. According to the hepatobiliary scintigraphy findings, patients were categorized into a nonvisualization of gallbladder activity (nonvisualized GB) group, low gallbladder ejection fraction (GBEF) group, and normal GBEF group. Differences in histopathologic factors between the three groups were evaluated and multivariate logistic regression analyses were performed to identify histopathological predictors for hepatobiliary scintigraphy findings.

RESULTS

The nonvisualized group had a higher frequency of patients with empyema and severe infiltration by neutrophils, lymphoplasma cells, and eosinophils. The low GBEF group had a higher muscle-to-total wall thickness ratio and muscle-to-fibrosis thickness ratio of the gallbladder wall than those in the normal GBEF group. On multivariate logistic regression analyses, severe degrees of lymphoplasma cell infiltration and eosinophil infiltration were independent predictors for nonvisualization of gallbladder activity, and a higher muscle-to-fibrosis thickness ratio was an independent predictor for low GBEF.

CONCLUSIONS

In patients with recurrent biliary colic, nonvisualization of gallbladder activity on hepatobiliary scintigraphy was related to the degree of inflammation in the gallbladder, while low GBEF was related to muscular hypertrophy of the gallbladder.

Role of Ultrasound and CT in the Workup of Right Upper Quadrant Pain in Adults in the Emergency Department: A Retrospective Review of More Than 2800 Cases

OBJECTIVE. The purpose of this study was to compare ultrasound and CT in the diagnostic evaluation of right upper quadrant pain in adults in the emergency department. MATERIALS AND METHODS. A retrospective review was conducted of adult emergency department encounters for right upper quadrant pain over a 5-year period, excluding those for prior cholecystectomy, current pregnancy, and trauma. Imaging study reports were reviewed for gallbladder and nongallbladder explanations of right upper quadrant pain and were considered positive for cholecystitis when two or more supportive features were present. Encounter outcomes were evaluated on the basis of pathology data and clinical management. RESULTS. Among the encounters, 2859 met the study inclusion criteria, and 18% met the study definition of cholecystitis by pathologic or clinical criteria. The following metrics showed no statistically significant difference between ultrasound and CT, respectively: sensitivity, 61% and 55%; specificity, 91% and 92%; positive predictive value, 63% and 63%; and negative predictive value, 91% and 90%. Both modalities were performed in 20% of encounters. In the subgroup analysis, ultrasound showed an acute nongallbladder abnormality that was missed at a preceding CT examination in only 1 of 238 cases (0.4%). CT showed an acute nongallbladder abnormality missed at a preceding ultrasound examination in 103 of 322 cases (32%). CONCLUSION. CT is noninferior to ultrasound in both ruling in and ruling out the diagnosis of cholecystitis in adult patients undergoing emergency evaluation of right upper quadrant pain and offers the advantage of depicting acute nongallbladder abnormalities.