Background: Magnetic resonance imaging (MRI) of the heart generally requires breath holding and a regular rhythm. Single shot 2D steady-state free precession (SS_SSFP) is a fast sequence insensitive to arrhythmia as well as breath holding. Our purpose was to determine image quality, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios and infarct size with a fast single shot and a standard segmented MRI sequence in patients with permanent atrial fibrillation and chronic myocardial infarction.
Methods: Twenty patients with chronic myocardial infarction and ongoing atrial fibrillation were examined with inversion recovery SS_SSFP and segmented inversion recovery 2D fast gradient echo (IR_FGRE). Image quality was assessed in four categories: delineation of infarcted and non-infarcted myocardium, occurrence of artefacts and overall image quality. SNR and CNR were calculated. Myocardial volume (ml) and infarct size, expressed as volume (ml) and extent (%), were calculated, and the methodological error was assessed.
Results: SS_SSFP had significantly better quality scores in all categories (P = 0.037, P = 0.014, P = 0.021, P = 0.03). SNR(infarct) and SNR(blood) were significantly better for IR_FGRE than for SS_SSFP (P = 0.048, P = 0.018). No significant difference was found in SNR(myocardium) and CNR. The myocardial volume was significantly larger with SS_SSFP (170.7 versus 159.2 ml, P<0.001), but no significant difference was found in infarct volume and infarct extent.
Conclusion: SS_SSFP displayed significantly better image quality than IR_FGRE. The infarct size and the error in its determination were equal for both sequences, and the examination time was shorter with SS_SSFP.