Diagnostic accuracy of late iodine enhancement on cardiac CT for myocardial tissue characterization: a systematic review and meta-analysis

Purpose: to evaluate the diagnostic accuracy of late iodine enhancement (LIE) in cardiac computed tomography (CCT) compared to late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) for myocardial tissue characterization. Materials and methods: EMBASE, PubMed/MEDLINE, and CENTRAL were searched for studies reporting the accuracy of LIE with LGE as the gold standard of reference. QUADAS-2 tool was used to assess the risk of bias. A bivariate random-effects model was used to analyze, pool, and plot the diagnostic performance measurements across studies. Pooled sensitivity, specificity, positive (+LR) and negative (−LR) likelihood ratio, diagnostic odds ratio (DOR), and hierarchical summary ROC curve (HSROC) were computed. Prospero registration number: CRD42023484045. Results: Fourteen studies involving 526 patients and 5758 myocardial segments were included. At the patient level, LIE in CCT showed a pooled sensitivity of 0.96 (95% CI: 0.88–0.99), specificity of 0.95 (95% CI: 0.88–0.98) and the HSROC AUC of 0.98 (95% CI: 0.97–0.99). The +LR was 20.97 (95% CI: 7.54–58.38) and the −LR was 0.04 (95% CI: 0.01–0.13), resulting in a DOR of 535 (95% CI: 94–3024). At the segment level, sensitivity was 0.86 (95% CI: 0.79–0.91), specificity was 0.98 (95% CI: 0.96–0.99), and the HSROC AUC was 0.97 (95% CI:0.95–0.98). The +LR was 55.08 (95% CI: 19.94–152.16) and the −LR was 0.14 (95% CI: 0.09–0.22) with a DOR of 388 (95% CI: 113–1333). Dual-energy CCT improved segment-level sensitivity to 0.93 (95% CI: 0.88–0.96). Conclusion: LIE in CCT shows excellent diagnostic accuracy when compared to LGE in CMR for myocardial tissue characterization, suggesting its potential as a promising alternative to CMR. Key Points: Question How does myocardial tissue characterization by late iodine enhancement (LIE) on cardiac CT (CCT) compare to late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR)? Findings LIE in CCT demonstrates excellent diagnostic accuracy, with high sensitivity and specificity at both patient and segment levels, using LGE in CMR as the reference. Clinical relevance LIE in CCT provides a reliable alternative to LGE in CMR, especially for patients for whom CMR is not available or feasible or is contraindicated, thus improving access to myocardial tissue characterization.