Imaging modalities for inguinal hernia diagnosis: a systematic review

Purpose: The aim of the study was to determine which diagnostic modality [Computerized Tomography (CT), Magnetic Resonance Imaging (MRI), or ultrasound (US)] is more precise in terms of sensitivity and specificity in diagnosing inguinal hernia and sub-type of inguinal hernia (direct or indirect). Methods: This systematic review was reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), and a search for relevant articles was undertaken in PubMed, Embase, and the Cochrane Library. Inclusion criteria were original studies that preoperatively diagnosed patients suspected of inguinal hernia by either CT, MRI, or US and compared diagnostic findings with operative findings or definitive follow-up. The main outcomes were the diagnostic certainty of inguinal hernia and type of hernia by sensitivity and specificity. All eligible studies were searched in the Retraction Watch database to ensure that all included studies were suitable for inclusion. Results: Bubble charts depicting the size of each patient cohort and percentual range for both sensitivity and specificity showed that US was better than CT and MRI in diagnosing inguinal hernia. Bubble charts for US and CT depicted high values within the studies that reported sensitivity and specificity in diagnosing type of hernia. Conclusions: We found that US had the highest sensitivity and specificity. However, it must be taken into consideration that performance is highly dependent on the operator’s level of expertise. Based on this systematic review, ultrasound may be the preferred imaging modality when physical examination is inconclusive, given that local expertise in performing US examination for hernia disease is adequate.