# What imaging modalities should be considered in suspected acute acalculous cholecystitis? A review of the evidence

## TL;DR

This paper reviews imaging methods for diagnosing acute acalculous cholecystitis and highlights the need for standardized protocols.

## Contribution

The study evaluates the diagnostic performance of various imaging modalities for acute acalculous cholecystitis and emphasizes the need for standardization.

## Key findings

- Ultrasound (US) has high specificity but variable sensitivity for diagnosing acute acalculous cholecystitis.
- HIDA scans show good specificity but inconsistent sensitivity.
- CT and MRI offer limited additional benefit over US for diagnosis but may aid in ruling out other conditions.

## Abstract

Radiological assessment remains crucial for acute acalculous cholecystitis (AAC) diagnosis, however, there is debate regarding the optimal imaging pathway. In the clinical setting, the decision to intervene, and the chosen procedure, are greatly influenced by imaging findings, and there is a need for a clear evaluation of each imaging modality’s proficiency for AAC detection and its prognostic utility.

We performed a survey of the literature on the radiological diagnosis of AAC. Prospective and retrospective studies were selected if they examined the diagnostic utility of the imaging modality using histology as the ground truth, and had a sample size of greater than ten patients.

Seventeen relevant studies were identified, which analysed US, hepatobiliary iminodiacetic acid (HIDA) scan, CT or MRI. The US has a reported specificity of between 93% and 97%, however, the sensitivity varied widely from 20% to 100%. The specificity of HIDA was reported as between 78% and 100%, but again, the sensitivity varied, between 38% and 100%. The literature on CT and MRI is limited, and there is no clear benefit over US for AAC diagnosis, however, they may be valuable for ruling out other diagnoses, or for surgical planning.

While radiological assessment holds utility in the management of suspected AAC, further research is required to properly define its role. Future research should focus on well-designed prospective studies to establish the diagnostic performance of both individual and multimodal imaging strategies in AAC, as well as the standardisation of imaging criteria and protocols across institutions.

Prompt radiological diagnosis of AAC can prevent complications and improve patient survival, however, radiological assessment still varies between institutions. Consequently, there is an urgent need for the diagnostic performance of imaging strategies to be established, and protocols across institutions to be standardised.

Radiological assessment is crucial for early diagnosis and prompt management of AAC.CT, MRI and HIDA scans demonstrate minimal benefit over US for diagnosis.Further research is required for evidence-based standardisation of imaging criteria and protocols.

Radiological assessment is crucial for early diagnosis and prompt management of AAC.

CT, MRI and HIDA scans demonstrate minimal benefit over US for diagnosis.

Further research is required for evidence-based standardisation of imaging criteria and protocols.