Paredes Matias, Castillo-Passi Carlos, Kunze Karl P, Fotaki Anastasia, Littlewood Simon, Botnar René M, Prieto Claudia
School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile.
Millennium Institute for Intelligent Healthcare Engineering, Santiago, Chile.
Magn Reson Med. 2025 Nov;94(5):1982-1996. doi: 10.1002/mrm.30611. Epub 2025 Jun 23.
To evaluate the feasibility of a novel, non-contrast enhanced, 3D, simultaneous bright-blood, and black-blood sequence (iT2prep-BOOST) for aortic imaging at 0.55 T at either systole or diastole.
Simultaneous contrast-free 3D aortic lumen and vessel wall imaging at 0.55 T is achieved using the recently introduced iT2prep-BOOST framework that interleaves the acquisition of two bright blood images (with inversion recovery T preparation [T2prep-IR] and no preparation). To enable either systolic or diastolic aortic imaging, three T preparation pulses were investigated-an adiabatic RF pulse and two Malcolm-Levitt (MLEV) pulses (MLEV4 and MLEV8)-to improve image quality in regions with high flow and susceptibility. The proposed approach was evaluated in phantom, 10 healthy subjects and 3 patients with suspected cardiovascular disease. Bright- and black-blood images resulting from the three different T preparation pulses were compared both qualitatively and quantitatively, using a 4-point Likert scale for vessel sharpness and presence of blood artifacts. Additionally, the contrast ratio between the lumen and myocardium was computed. Aortic measurements, including the aortic annulus area at systole and diastole, cusp-commissure measurement at the aortic root level during diastole, and aortic diameter at the ascending aortic level during diastole were also performed.
Excellent or good image quality scores were obtained for both bright- and black-blood images with iT2prep-BOOST at 0.55 T with all three preparation pulses. The use of MLEV8 T preparation scheme improves systolic image quality, reducing the presence of artifacts with a significant difference (p < 0.05) at the mid descending aorta level. This scheme also increases the contrast ratio between aortic lumen and myocardium, compared to the previously used adiabatic RF T preparation. The aortic root diameter and area were consistent with values reported in the literature for healthy subjects at 1.5 T.
The feasibility of a novel, non-contrast-enhanced, 3D aortic imaging framework for simultaneous bright-blood and black-blood imaging was demonstrated at 0.55 T for either systole or diastole, with a scan time of 7 min. Good image quality scores and aortic measurements in agreement with literature values at 1.5 T were achieved with the MLEV8 T preparation. Studies in a larger cohort of healthy subjects and patients with aortopathies are warranted.
评估一种新型的、无需对比增强的三维同步亮血和黑血序列（iT2prep - BOOST）在0.55 T场强下于收缩期或舒张期进行主动脉成像的可行性。
使用最近引入的iT2prep - BOOST框架在0.55 T场强下实现同步无对比剂的三维主动脉管腔和血管壁成像，该框架交错采集两幅亮血图像（采用反转恢复T准备 [T2prep - IR] 和无准备）。为实现收缩期或舒张期主动脉成像，研究了三种T准备脉冲——一个绝热射频脉冲和两个马尔科姆 - 莱维特（MLEV）脉冲（MLEV4和MLEV8）——以改善高血流和高磁化率区域的图像质量。在体模、10名健康受试者和3名疑似心血管疾病患者中对所提出的方法进行评估。使用4分李克特量表对血管清晰度和血液伪影的存在情况，对三种不同T准备脉冲产生的亮血和黑血图像进行定性和定量比较。此外，计算管腔与心肌之间的对比度。还进行了主动脉测量，包括收缩期和舒张期的主动脉瓣环面积、舒张期主动脉根部水平的瓣尖 - 瓣交界测量以及舒张期升主动脉水平的主动脉直径。
在0.55 T场强下，使用iT2prep - BOOST和所有三种准备脉冲时，亮血和黑血图像均获得了优秀或良好的图像质量评分。使用MLEV8 T准备方案可提高收缩期图像质量，减少降主动脉中部水平伪影的出现，差异具有统计学意义（p < 0.05）。与先前使用的绝热射频T准备相比，该方案还增加了主动脉管腔与心肌之间的对比度。主动脉根部直径和面积与文献报道的1.5 T场强下健康受试者的值一致。
在0.55 T场强下，无论是收缩期还是舒张期，都证明了一种新型的、无需对比增强的三维主动脉成像框架用于同步亮血和黑血成像的可行性，扫描时间为7分钟。使用MLEV8 T准备可获得良好的图像质量评分，且主动脉测量结果与1.5 T场强下的文献值一致。有必要对更大规模的健康受试者和主动脉病变患者队列进行研究。
