PDF(Pubmed)
Abstract：
Late gadolinium enhancement (LGE) MRI is the non-invasive reference standard for identifying myocardial scar and fibrosis but has limitations, including difficulty delineating subendocardial scar and operator dependence on image quality. The purpose of this work is to assess the feasibility of generating multi-contrast synthetic LGE images from post-contrast T1 and T2 maps acquired using magnetic resonance fingerprinting (MRF). Fifteen consecutive patients with a history of prior ischemic cardiomyopathy (12 men; mean age 63 ± 13 years) were prospectively scanned at 1.5 T between Oct 2020 and May 2021 using conventional LGE and MRF after injection of gadolinium contrast. Three classes of synthetic LGE images were derived from MRF post-contrast T1 and T2 maps: bright-blood phase-sensitive inversion recovery (PSIR), black- and gray-blood T2 -prepared PSIR (T2 -PSIR), and a novel \"tissue-optimized\" image to enhance differentiation among scar, viable myocardium, and blood. Image quality was assessed on a 1-5 Likert scale by two cardiologists, and contrast was quantified as the mean absolute difference (MAD) in pixel intensities between two tissues, with different methods compared using Kruskal-Wallis with Bonferroni post hoc tests. Per-patient and per-segment scar detection rates were evaluated using conventional LGE images as reference. Image quality scores were highest for synthetic PSIR (4.0) and reference images (3.8), followed by synthetic tissue-optimized (3.3), gray-blood T2 -PSIR (3.0), and black-blood T2 -PSIR (2.6). Among synthetic images, PSIR yielded the highest myocardium/scar contrast (MAD = 0.42) but the lowest blood/scar contrast (MAD = 0.05), and vice versa for T2 -PSIR, while tissue-optimized images achieved a balance among all tissues (myocardium/scar MAD = 0.16, blood/scar MAD = 0.26, myocardium/blood MAD = 0.10). Based on reference mid-ventricular LGE scans, 13/15 patients had myocardial scar. The per-patient sensitivity/accuracy for synthetic images were the following: PSIR, 85/87%; black-blood T2 -PSIR, 62/53%; gray-blood T2 -PSIR, 100/93%; tissue optimized, 100/93%. Synthetic multi-contrast LGE images can be generated from post-contrast MRF data without additional scan time, with initial feasibility shown in ischemic cardiomyopathy patients.
摘要：
晚期钆增强（LGE）MRI是用于识别心肌瘢痕和纤维化的非侵入性参考标准，但有局限性，包括难以描绘心内膜下瘢痕和操作者对图像质量的依赖。这项工作的目的是评估从使用磁共振指纹（MRF）采集的对比后T1和T2图生成多对比合成LGE图像的可行性。在2020年10月至2021年5月之间，使用常规LGE和MRF在注射钆对比剂后，在1.5T前瞻性扫描了15例有缺血性心肌病病史的连续患者（12名男性；平均年龄63±$$$\\pm$13年）。从MRF对比后T1和T2图得出三类合成LGE图像：亮血相敏反转恢复（PSIR），黑血和灰血T2制备的PSIR（T2-PSIR），以及一种新颖的“组织优化”图像，以增强疤痕之间的差异，存活心肌，还有血.由两名心脏病专家以1-5李克特量表评估图像质量，和对比度被量化为两个组织之间的像素强度的平均绝对差（MAD），与使用Kruskal-Wallis和Bonferroni事后检验的不同方法进行比较。使用常规LGE图像作为参考，评估了每位患者和每段疤痕的检出率。合成PSIR（4.0）和参考图像（3.8）的图像质量得分最高，其次是合成组织优化(3.3)，灰血T2-PSIR（3.0），和黑血T2-PSIR（2.6）。在合成图像中，PSIR产生最高的心肌/瘢痕对比（MAD=0.42），但最低的血液/瘢痕对比（MAD=0.05），对于T2-PSIR，反之亦然，而组织优化的图像在所有组织之间实现了平衡（心肌/瘢痕MAD=0.16，血液/瘢痕MAD=0.26，心肌/血液MAD=0.10）。根据参考心室中段LGE扫描，13/15患者有心肌瘢痕。合成图像的每位患者灵敏度/准确度如下：PSIR，85/87%;黑血T2-PSIR,62/53%;灰血T2-PSIR,100/93%；组织优化，100/93%。可以从对比后MRF数据生成合成多对比LGE图像，而无需额外的扫描时间，在缺血性心肌病患者中具有初步可行性。
