Abstract WP125: Accelerated 3d Isotropic High-resolution Multi-contrast Intracranial Vessel Wall MRI For Large Artery Stroke Evaluation
Introduction: Intracranial large-artery atherosclerotic disease (ICAD) is a leading cause of death and morbidity worldwide. Vessel Wall Imaging (VWI) has potential to stratify disease beyond current angiographic methods by identifying plaque morphology and components directly. Plaque component identification requires a multi-contrast black-blood protocol. High isotropic resolution is also required due to small vessels and their complex geometry and therefore typical ICAD VWI protocols require long scan times. Aim: To develop a 3D 0.5 mm isotropic multi-contrast ICAD VWI with scan time of less than 30 minutes. Methods: Experiments were carried out on a Philips Ingenia 3T scanner with 32 channel head coil. Acceleration by K-space undersampling using CUSTOM method and compressed sensing reconstruction using STEP method [1] was used to reduce scan times. The following protocol was optimized on phantoms and volunteers: Survey scan was followed by 3D TOF, T1 weighted VISTA, PD weighted DANTE [2] VISTA, SNAP [3]. After single dose gadolinium contrast injection a post-contrast T1 weighted VISTA is obtained. Protocol parameters were optimized such that total scan time is 25 mins with all scans (except survey) being 0.5mm isotropic. Results: CUSTOM acceleration factors of 4X to 5X provided good image quality. Representative image quality (pre-contrast) is shown in figure 1. Total scan time for the multi-contrast protocol was 30 minutes including patient setup time. Studies on ICAD patients are ongoing with the optimized protocol. Conclusions: Multi-contrast 3D 0.5mm isotropic resolution MRI protocol was developed to scan ICAD patients within 30 minute scan time. Acceleration tailored for VWI allowed reducing scan times from 2 hours to less than 30 minutes thereby providing a clinically usable ICAD VWI multi-contrast protocol. References: [1] Zhou Z et al, MRM 2016, [2] Li L et al, MRM 2012, [3] Wang et al, MRM 2013.