导航引导运动和 T2*-加权磁共振成像的 B0 校正可提高多发性硬化症皮质病变的检测。
Navigator-Guided Motion and B0 Correction of T2*-Weighted Magnetic Resonance Imaging Improves Multiple Sclerosis Cortical Lesion Detection.
机构信息
From the Advanced MRI Section.
Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD.
出版信息
Invest Radiol. 2021 Jul 1;56(7):409-416. doi: 10.1097/RLI.0000000000000754.
BACKGROUND
Cortical lesions are common in multiple sclerosis (MS). T2*-weighted (T2*w) imaging at 7 T is relatively sensitive for cortical lesions, but quality is often compromised by motion and main magnetic field (B0) fluctuations.
PURPOSE
The aim of this study was to determine whether motion and B0 correction with a navigator-guided gradient-recalled echo sequence can improve cortical lesion detection in T2*w magnetic resonance imaging.
MATERIALS AND METHODS
In this prospective study, a gradient-recalled echo sequence incorporating a navigator allowing for motion and B0 field correction was applied to collect T2w images at 7 T from adults with MS between August 2019 and March 2020. T2-weighted images were acquired in 1 to 3 partially overlapping scans per individual and were reconstructed using global average B0 correction ("uncorrected") or motion correction and spatially linear B0 correction ("corrected"). Image quality rating and manual segmentation of cortical lesions were performed on uncorrected and corrected images. Lesions seen on a single scan were retrospectively evaluated on the complementary scan. The association of cortical lesions with clinical disability was assessed. Mixed models were used to determine the effect of correction on lesion detection as well as on the relationship between disability and lesion count.
RESULTS
A total of 22 T2*w scans were performed on 11 adults with MS (mean [SD] age, 49 [11] years; 8 women). Quality improved for 20 of 22 scans (91%) after correction. A total of 69 cortical lesions were identified on uncorrected images (median per scan, 2; range, 0-11) versus 148 on corrected images (median per scan, 4.5; range, 0-25; rate ratio [RR], 2.1; P < 0.0001). For low-quality uncorrected scans with moderate to severe motion artifact (18/22, 82%), there was an improvement in cortical lesion detection with correction (RR, 2.5; P < 0.0001), whereas there was no significant change in cortical lesion detection for high-quality scans (RR, 1.3; P = 0.43).
CONCLUSIONS
Navigator-guided motion and B0 correction substantially improves the overall image quality of T2*w magnetic resonance imaging at 7 T and increases its sensitivity for cortical lesions.
背景
皮质病变在多发性硬化症（MS）中很常见。7T 下的 T2*-加权（T2*w）成像是检测皮质病变相对敏感的方法，但由于运动和主磁场（B0）波动，其质量往往会受到影响。
目的
本研究旨在确定使用导航引导的梯度回波序列进行运动和 B0 校正是否可以提高 T2*w 磁共振成像中皮质病变的检测能力。
材料和方法
在这项前瞻性研究中，我们在 2019 年 8 月至 2020 年 3 月期间，对患有 MS 的成年人使用纳入导航功能的梯度回波序列来采集 7T 下的 T2*w 图像。每位个体采集 1 到 3 次部分重叠的扫描，并使用全局平均 B0 校正（“未校正”）或运动校正和空间线性 B0 校正（“校正”）重建图像。在未校正和校正图像上进行图像质量评分和皮质病变的手动分割。对单扫描上可见的病变在互补扫描上进行回顾性评估。评估皮质病变与临床残疾之间的关联。使用混合模型确定校正对病变检测的影响以及残疾与病变计数之间的关系。
结果
对 11 名 MS 患者（平均年龄，49[11]岁；8 名女性）的 22 次 T2*w 扫描进行了分析。校正后，22 次扫描中有 20 次（91%）的质量得到改善。在未校正图像上共发现 69 个皮质病变（中位数，每扫描 2 个；范围，0-11），而在校正图像上共发现 148 个皮质病变（中位数，每扫描 4.5 个；范围，0-25；比率比[RR]，2.1；P<0.0001）。对于有中度到重度运动伪影的低质量未校正扫描（18/22，82%），校正后皮质病变的检测能力有所提高（RR，2.5；P<0.0001），而高质量扫描的皮质病变检测能力没有显著变化（RR，1.3；P=0.43）。
结论
导航引导的运动和 B0 校正可大大提高 7T T2*w 磁共振成像的整体图像质量，并提高其检测皮质病变的敏感性。
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