Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China.
Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, 94720, USA.
J Magn Reson Imaging. 2021 Jun;53(6):1823-1832. doi: 10.1002/jmri.27464. Epub 2020 Dec 9.
The fimbria is a small white matter bundle that connects the hippocampus to the rest of the brain. Damage to the hippocampal gray matter is established in Alzheimer's disease (AD), but the hippocampal fimbrial status in the pathogenesis of AD is unclear. AD-related demyelination and iron deposition alter the diamagnetic and paramagnetic composition of tissues, which can be measured by quantitative susceptibility mapping (QSM).
AD is associated with microstructural changes in the fimbria that might be detected by QSM.
Retrospective cross-sectional study.
In all, 53 adults comprised of controls (n = 30), subjects with early stage AD (n = 13), and late stage AD (n = 10) who were classified according to their amyloid and tau status and presence of hippocampal atrophy.
FIELD STRENGTH / SEQUENCE: 3T; 3D fast-field echo sequence for QSM analysis and 3D T -weighted MP-RAGE sequence for anatomical analysis.
Segmentation of the left hippocampal fimbria subfield was performed on T -weighted images and was applied to the coregistered QSM map for extraction of the mean, median, minimum, and maximum values of QSM.
Group comparison of QSM values using analysis of variance (ANOVA) with post-hoc Tukey's test, accuracy of binary differentiation using receiver operating characteristic (ROC), and individual classification using discriminant analysis.
QSM and QSM values were significantly different among the three groups (P < 0.05) and showed a shifting from negative in the control group to positive in the AD group. The control and early AD subjects, who have normal hippocampal volumes, were differentiated by the QSM value (area under the curve [AUC] 0.744, P < 0.05) and the QSM value (AUC 0.782, P < 0.05). Up to 76% of subjects (inclusive of 26 controls and six with early AD) were correctly classified using a model incorporating clinical and radiologic data.
The fimbria showed higher magnetic susceptibility in AD compared with controls.
2 TECHNICAL EFFICACY STAGE: 3.
穹窿是连接海马体和大脑其他部位的一个小白质束。在阿尔茨海默病（AD）中，海马体灰质的损伤已得到确立，但穹窿在 AD 发病机制中的状态尚不清楚。AD 相关的脱髓鞘和铁沉积改变了组织的抗磁性和顺磁性成分，这可以通过定量磁化率映射（QSM）来测量。
AD 与穹窿的微观结构变化有关，这些变化可能通过 QSM 检测到。
回顾性横断面研究。
共纳入 53 名成年人，包括对照组（n = 30）、早期 AD 患者（n = 13）和晚期 AD 患者（n = 10），他们根据淀粉样蛋白和 tau 状态以及海马体萎缩的存在进行分类。
磁场强度/序列：3T；用于 QSM 分析的 3D 快速场回波序列和用于解剖学分析的 3D T1 -加权 MP-RAGE 序列。
在 T1 -加权图像上对左侧海马穹窿亚区进行分割，并将其应用于配准的 QSM 图中，以提取 QSM 的平均值、中位数、最小值和最大值。
采用方差分析（ANOVA）比较组间 QSM 值，并进行事后 Tukey 检验，采用受试者工作特征（ROC）分析比较二分类的准确性，采用判别分析进行个体分类。
三组间 QSM 值差异有统计学意义（P<0.05），且从对照组的负向到 AD 组的正向变化。具有正常海马体容积的对照组和早期 AD 患者可通过 QSM 值（曲线下面积[AUC]0.744，P<0.05）和 QSM 值（AUC 0.782，P<0.05）进行区分。通过纳入临床和影像学数据的模型，有 76%的受试者（包括 26 名对照组和 6 名早期 AD 患者）得到正确分类。
与对照组相比，AD 中的穹窿显示出更高的磁化率。
2 技术功效分级：3
