Integrated imaging of cardiac anatomy, physiology, and viability

Inversion-recovery single-shot cardiac MRI for the assessment of myocardial infarction at 1.5 T with a dedicated cardiac coil

OBJECTIVE

The aim of this study was to assess the diagnostic accuracy of imaging myocardial infarction with a two-dimensional (2D) single-shot inversion-recovery (IR)-gradient-echo (GE) sequence compared with a standard 2D segmented IR-GE sequence at 1.5 T using a dedicated cardiac coil.

METHODS

22 patients with myocardial infarction documented in the past 3-12 months were examined at 1.5 T using a 5 channel cardiac coil. Imaging of delayed enhancement was performed 15 min after administration of 0.2 mmol of gadopentetate dimeglumine per kilogram of body weight. Immediately after completion of the single-shot sequence, which allows for coverage of the entire ventricle during a single breath-hold with nine slices, the segmented IR sequence was started. Infarct volumes, infarct transmurality and contrast-to-noise ratios (CNRs) of infarcted and healthy myocardium were compared between both techniques.

RESULTS

Despite a moderate, non-significant loss of CNR (CNR(single-shot IR)=31.2±4.1; CNR(segmented IR)=37.9±4.1; p=0.405), the 2D single-shot technique correctly determined infarct size when compared with the standard 2D segmented IR-GE sequence. Assessment of both infarct volume (r=0.95; p<0.0001) and transmurality (r=0.97; p<0.0001) is possible, with excellent correlation of both techniques.

CONCLUSION

Single-shot delayed enhancement imaging during a single breath-hold is feasible at 1.5 T with the use of a dedicated cardiac coil. Despite a moderately lower CNR, the single-shot technique allows for fast and accurate determination of infarct size with high spatial resolution and has the potential to reduce electrocardiogram and breathing artefacts.