Background Cardiac MRI at 5 T has recently become available and potentially improves tissue contrast enhancement at gadolinium chelate-enhanced T1-weighted imaging. Purpose To evaluate the feasibility of 5-T myocardial late gadolinium enhancement (LGE) MRI in assessing myocardial fibrosis by comparing image quality and LGE quantification with reference-standard 3-T myocardial LGE MRI. Materials and Methods Consecutive patients with confirmed myocardial fibrosis on previous 3-T MRI scans between January 2023 and July 2023 prospectively underwent follow-up imaging from August 2023 to November 2023. Each participant underwent follow-up 5-T imaging using an identical dose of contrast agent. Radiologist scoring of image quality using a Likert scale (range, 1-5), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), contrast ratio, and semiautomatic quantitative LGE assessment were obtained and reported as medians and IQRs. Paired Wilcoxon signed rank tests were used to compare characteristics derived at 3-T and 5-T imaging. Results A total of 18 participants (mean age, 49 years ± 17 [SD]; nine male participants) were included, with a mean interval of 6.2 months ± 2.3 between undergoing 3-T and 5-T MRI. Median image quality scores were 4.0 (IQR, 3.0-4.2) at 3 T and 4.0 (IQR, 3.0-4.4) at 5 T (P = .45). SNR at 5 T was higher than at 3 T (183.7 [IQR, 147.2-255.9] vs 125.8 [IQR, 108.2-171.6], respectively; P = .002). Median CNR at 5 T was higher than at 3 T in normal myocardium (50.8 [IQR, 35.4-67.9] vs 16.5 [IQR, 11.3-24.6], respectively) and pericardial fat (21.4 [IQR, 7.1-29.3] vs -5.0 [IQR, -16.4 to -2.3], respectively) (both P < .001). There was no evidence of a difference in the percentage of LGE quantified between 5 T and 3 T (median, 11.8% [IQR, 7.7%-20.5%] vs 12.6% [IQR, 6.6%-20.4%], respectively; P = .81). Conclusion Myocardial LGE MRI at 5 T was found to be feasible, with no evidence of differences in subjective image quality and myocardial fibrosis quantification compared with 3-T myocardial LGE MRI. Furthermore, with use of identical contrast agent doses, SNRs and CNRs were improved at 5 T. Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Czum in this issue.

中文翻译：

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3-T 与 5-T 心肌晚期钆增强 MRI 的心肌纤维化评估：早期结果。


背景 5 T 的心脏 MRI 最近已经可用，并可能改善钆螯合物增强 T1 加权成像的组织对比度增强。目的 通过将图像质量和 LGE 定量与参考标准 3-T 心肌 LGE MRI 进行比较，评估 5-T 心肌晚期钆增强 （LGE） MRI 评估心肌纤维化的可行性。材料和方法： 2023 年 1 月至 2023 年 7 月期间既往 3-T MRI 扫描确诊心肌纤维化的连续患者，前瞻性地接受了 2023 年 8 月至 2023 年 11 月的随访影像学检查。每个参与者都使用相同剂量的造影剂接受了 5-T 成像随访。使用李克特量表 （范围，1-5）、信噪比 （SNR）、对比比 （CNR）、对比比和半自动定量 LGE 评估获得放射科医生对图像质量进行评分，并以中位数和 IQR 报告。配对 Wilcoxon 符号秩检验用于比较 3-T 和 5-T 成像得出的特征。结果 共纳入 18 名参与者 （平均年龄 49 岁 ± 17 [SD];9 名男性参与者），接受 3-T 和 5-T MRI 的平均间隔为 6.2 个月± 2.3 个月。图像质量中位数评分在 3 T 时为 4.0 （IQR，3.0-4.2），在 5 T 时为 4.0 （IQR，3.0-4.4） （P = .45）。5 T 时的 SNR 高于 3 T 时的 SNR（分别为 183.7 [IQR，147.2-255.9] 和 125.8 [IQR，108.2-171.6];P = .002）。正常心肌 （分别为 50.8 [IQR，35.4-67.9] 和 16.5 [IQR，11.3-24.6]）和心包脂肪 （分别为 21.4 [IQR，7.1-29.3] 和 -5.0 [IQR，-16.4 至 -2.3]）（分别为 P < .001）。没有证据表明 5 T 和 3 T 之间量化的 LGE 百分比存在差异（中位数，11.8% [IQR，7.7%-20.5%] vs 12。分别为 6% [IQR， 6.6%-20.4%];P = .81）。结论 发现 5 T 心肌 LGE MRI 是可行的，没有证据表明与 3-T 心肌 LGE MRI 相比，主观图像质量和心肌纤维化量化存在差异。此外，在使用相同的造影剂剂量的情况下，SNR 和 CNR 在 5 T 下得到改善。本文提供了补充材料。另请参见 Czum 在本期的社论。