Improvement of the Image Quality of Black-blood Magnetic Resonance Imaging with the Subtraction Double Inversion Recovery Technique

Black-blood images acquired with the double inversion recovery (IR) sequence in cardiovascular magnetic resonance imaging are commonly applied to distinguish the vessel wall from the lumen to evaluate vascular pathology. However, inadequate suppression of blood signals may introduce artifacts and cause mistakes. The objective of the current study was to determine whether subtraction double IR black-blood imaging improved the image quality. 11 scans from four rabbits were scanned using the conventional and subtraction T1 weighted double IR imaging. The subtraction method involved two scans with a third IR sequence with a series of inversion time (TI) settings in one of them. Each black-blood image was qualitatively evaluated based on contrast-to-noise ratio (CNR), signal-tonoise ratio (SNR), and noises. Using the best TI setting (575 ms), subtraction black-blood imaging yielded significantly better black-blood effects with a 48.6% increase in mean CNR between the area of the left carotid artery and adjacent paravertebral muscles (PM) and a 30.7% increase in mean CNR between the area of the left jugular vein and adjacent PM compared with the conventional method (5.65 vs. 3.81 and 6.8 vs. 5.21, both p values < 0.05). The subtraction black-blood imaging did not significantly deteriorate image quality regarding noises and mean SNRs in the area of PM. Subtraction double IR black-blood imaging is better than the conventional method in black-blood effects of blood signals.