Added diagnostic performance of diffusion-weighted imaging for differentiating malignant from benign gallbladder lesions: a systematic review with meta-analysis

Gallbladder malignancies, especially gallbladder cancer, are aggressive lesions with a poor prognosis, and correct differentiation from benign lesions is crucial for improved outcomes. Recently, diffusion-weighted imaging (DWI) has demonstrated potential for this aim to evaluate suspicious lesions detected by initial imaging (e.g., ultrasound).

The protocol of this review was pre-registered at (https://osf.io/ury4k) PubMed, Web of Science, Embase, and Cochrane Library were searched. The performance of both qualitative (i.e., visual) and quantitative (i.e., apparent diffusion coefficient (ADC)) DWIs was assessed for visualized suspicious lesions detected on preliminary imaging. The added value of combining DWI with conventional magnetic resonance imaging (MRI) for this purpose was also evaluated.

After the screening, 27 studies were included. Qualitative analysis showed an area under curve (AUC) of 0.93 (95% confidence interval (CI) = 0.90 to 0.95), while AUC of quantitative analysis was 0.91 (95% CI = 0.89 to 0.94). Adding DWI to conventional MRI protocol added significant values of + 11.27% (95% CI = 0.78% to 21.76%) to sensitivity and + 9.64% (95% CI = 3.90% to 15.39%) to specificity for suspicious lesions on preliminary imaging.

DWI offers an accurate, noninvasive method for differentiating benign gallbladder lesions from malignant ones after preliminary imaging. While adding the DWI protocol to conventional MRI imaging does not require technical resources, it significantly improves performance.