Homologous HOmologous Black-Bright-blood and flexible Interleaved imaging sequence (HOBBI) for dynamic contrast-enhanced MRI of the vessel wall.

PURPOSE: To present a HOmologous Black-Bright-blood and flexible Interleaved imaging (HOBBI) sequence for dynamic contrast-enhanced magnetic resonance imaging (MRI) of the vessel wall.

THEORY AND

METHODS

A HOBBI sequence is proposed to acquire high-spatial-resolution black-blood and high-temporal-resolution bright-blood dynamic contrast-enhanced images in an interleaved fashion. Black-blood imaging allows for thin vessel wall evaluation, whereas bright-blood imaging obtains the arterial input function accurately. A simulation was performed to assess the accuracy of the pharmacokinetic parameters [transfer constant (K(trans) ) and fractional plasma volume (vp )] generated from HOBBI. In vivo evaluation was also used to validate HOBBI in an animal model of aortic atherosclerosis.

RESULTS

In the simulation test, the estimated K(trans) and vp measured by HOBBI were more accurate than those from black-blood dynamic contrast-enhanced-MRI. In the animal model testing, K(trans) and vp also demonstrated good interscan reproducibility (K(trans) : ICC = 0.77, vp : ICC = 0.72, respectively). Additionally, K(trans) showed a significant increase from 1 month (0.026 ± 0.013 min(-1) ) to 2 months (0.069 ± 0.018 min(-1) ) in animal model plaque progression after balloon injury.

CONCLUSION

The proposed HOBBI sequence was demonstrated to be feasible and accurate in estimating the pharmacokinetic parameters of the atherosclerotic vessel wall, and has potential to become an early screening tool for atherosclerosis disease.