Improved visualization of non-transmural scar using slice-selective inversion-recovery delayed contrast-enhanced MRI: A preliminary report

Delayed contrast-enhanced MRI (ce-MRI) pulse sequence is a promising modality for the assessment of myocardial viability. However, conventional ce-MRI using a non-selective inversion recovery (IR) pulse can often yield poor edge definition or contrast-to-noise ratio (CNR) between the non-transmural scar and blood (i.e. the blood and scar appear isointense). Subtraction and multicontrast ce-MRI methods can be used to improve the CNR between the non-transmural scar and blood, but they require two image acquisitions. The authors have developed a single-acquisition ce-MRI pulse sequence that utilizes a slice-selective IR pulse to generate bright-blood contrast using inflow effects for an improved edge definition between the non-transmural scar and blood. Six patients with myocardial infarction were imaged at 1.5 T using both non-selective and slice-selective IR ce-MRI acquisitions with identical imaging parameters. The CNR between the non-transmural scar and normal myocardium was not different between the two acquisitions. The CNR between the blood and non-transmural scar (16.9 ± 12.3 versus 3.2 ± 7.9; p < 0.001) was significantly higher for the slice-selective IR acquisition than for the non-selective IR acquisition. This study demonstrates the feasibility of using a slice-selective IR pulse to improve the visualization of a non-transmural scar in ce-MRI, without increasing the acquisition time.