6 A new way to image infarction: dark blood late gadolinium enhancement vs conventional imaging for the detection of scar

Background Conventional bright blood late gadolinium enhancement (LGE) imaging offers excellent contrast between areas of infarction and normal myocardium. However, contrast between subendocardial scar and blood is frequently poor. Dark blood LGE (DB LGE) employs an inversion recovery T2 preparation to suppress the blood pool, increasing contrast between the endocardium and blood. This study compares the diagnostic utility of a novel DB LGE sequence to standard bright blood LGE. Methods 172 patients were scanned. A full left ventricle short axis stack was performed using both techniques. Two observers scored presence and extent of LGE, along with how confident they were in their diagnoses, for all patients. Results 2752 LV segments were analysed. DB LGE found 41.5% more segments that showed LGE in comparison to bright blood (figure 1). DB imaging also allowed observers to be more confident when diagnosing LGE, assigning high confidence to 84.9% of DB LGE segments but only 62.1% when using bright blood. DB LGE identified missed myocardial infarctions in 18 patients with negative bright blood scans. Conclusions DB LGE imaging significantly increases LGE detection compared to standard bright blood imaging. It also increases observer confidence, particularly for subendocardial LGE. This may have important clinical implications for troponin-positive events with unobstructed coronaries.