Time-Efficient Black Blood RCA Wall Imaging at 3T Using Improved Motion Sensitized Driven Equilibrium (iMSDE): Feasibility and Reproducibility

Abstract

BackgroundThe aim of this study was to explore the feasibility and reproducibility of a time-efficient coronary vessel wall measurement approach using an improved motion-sensitized driven equilibrium (iMSDE) pulse sequence.MethodologyIn this study, the iMSDE pulse sequence was first optimized and then applied on a group of healthy volunteers (N = 10) to evaluate its feasibility of vessel wall visualization. The same technique was also applied on a separate group of volunteers (N = 19) for a reproducibility study by scanning the same subject in two separate sessions. The iMSDE sequence was found to provide good coronary vessel wall delineation. It was also found to provide reproducible coronary vessel wall diameter and thickness measurements in both proximal and middle segments of the right coronary artery.ConclusionThe feasibility and reproducibility of iMSDE based coronary vessel wall imaging were demonstrated for the first time, paving the way for further testing in a clinical environment for fast and accurate coronary artery disease detection.

Feasibility of coronary artery wall thickening assessment in asymptomatic coronary artery disease using phase-sensitive dual-inversion recovery MRI at 3T

“…The closest published methods at 3T using a 21ms acquisition window required repetition time of two heart beats (18) to obtain adequate blood signal nulling, SNR and CNR. To allow 3D imaging with a large volumetric coverage, repetition time of a single heart beat was predominantly utilized in 3D sequences in which TR=2 RR is not affordable due to the prohibitively long acquisition times (19, 20). The latter 3D sequences, therefore, are completed in long scan times ranging from 6–22 minutes.…”

“…Such challenges are accentuated at 3T mainly due to larger B 0 and B 1 inhomogeneities, and consequently shorter T 2 * compounded by the difference in inversion time due to the prolonged T 1 at higher field strength compared to 1.5T (18). Some of these challenges have been addressed by using improved motion-sensitized driven equilibrium (iMSDE) at 3T (19) to obtain homogeneous blood pool suppression or by using adiabatic inversion sequences (20). An alternative technique was to use phase-sensitive dual inversion recovery (PS-DIR) at 3T (21).…”

“…Previous studies that compared breath-hold PS-DIR to conventional DIR imaging in healthy subjects demonstrated a good agreement in vessel wall thickness as well as a significant improvement in lumen-wall CNR relative to standard DIR (21). Unlike the studies performed at 1.5T, the feasibility of these methods at 3T was primarily demonstrated in healthy subjects (18, 19, 21–24). To date only two studies (25, 26) utilized 3T vessel wall imaging to study subjects with CAD risk factors (25) or known CAD (26).…”

Three-Dimensional Carotid Plaque MR Imaging

“…Since the original introduction, several techniques were introduced to reduce this signal loss and explore its use in multiple contrast weighting and in other vascular applications (22, 24–26). Zhu, et al (23) recently published a study focused on the optimization of improved MSDE (iMSDE) module for both 2D and 3D blood suppression in T1W and T2W spin echo acquisition and demonstrated the feasibility.…”

3.0-T MR Imaging of Intracoronary Local Delivery of Motexafin Gadolinium into Coronary Artery Walls

“…(c) Cross-sectional T1-weighted images of the target coronary artery walls were acquired before and after infusion of 5 mL of the 150-µmol/L MGd and trypan blue mixture. The imaging parameters of T1-weighted MR imaging included a spin-echo sequence with improved motion-sensitized driven equilibrium (14) (600/21; field of view, 300 3 300 mm; 376 3 371 matrix; 5-mm section thickness; two signals acquired). For each of the targeted coronary artery segments, a total of four sections were obtained.…”