Division of Neonatology, Department of Pediatrics, The Johns Hopkins University School of Medicine, The Charlotte R. Bloomberg Children's Center, Baltimore, MD.
Neuro-Intensive Care Nursery Group, The Johns Hopkins School of Medicine, Baltimore, MD.
J Neuroimaging. 2019 Mar;29(2):252-259. doi: 10.1111/jon.12572. Epub 2018 Oct 16.
Neonatal hypoxic-ischemic injury of the brain and resultant encephalopathy (HIE) leads to major developmental impairments by school age. Conventional/anatomical MRI often fails to detect hippocampal injury in mild cases. We hypothesize that diffusion tensor imaging (DTI) has greater sensitivity for identifying subtle hippocampal injury.
We retrospectively analyzed DTI data collected from a cohort of neonates with HIE and controls. Conventional MRI sequences were classified qualitatively according to severity using a modified Barkovich scale. Using multivariate linear regression, we compared hippocampal DTI scalars of HIE patients and controls. Spearman correlation was used to test the association of DTI scalars in the hippocampal and thalamic regions. A multiple regression analysis tested the association of the DTI scalars with short-term outcomes.
Fifty-five neonates with HIE (42% males) and 13 controls (54% males) were included. Hippocampal DTI scalars were similar between HIE and control groups, even when restricting the HIE group to those with moderate-to-severe injury (8 subjects). DTI scalars of the thalamus were significantly lower in the moderate-to-severely affected patients compared to controls (right fractional anisotropy [FA] .148 vs. .182, P = .01; left FA .147 vs. .181, P = .03). Hippocampal and thalamic DTI scalars were correlated (P < .001). Hippocampal DTI scalars were not associated with short-term outcomes.
Quantitative DTI analysis of the hippocampus in neonates following HIE is a feasible technique to examine neuronal injury. Although DTI scalars were useful in identifying thalamic injury in our cohort, hippocampal DTI analysis did not provide additional information regarding hippocampal injury following HIE.
新生儿缺氧缺血性脑损伤和由此导致的脑病（HIE）会导致学龄期出现严重的发育障碍。常规/解剖磁共振成像（MRI）通常无法检测到轻度病例中的海马损伤。我们假设弥散张量成像（DTI）在识别细微海马损伤方面具有更高的敏感性。
我们回顾性分析了来自 HIE 新生儿和对照组的队列的 DTI 数据。使用改良 Barkovich 量表根据严重程度对常规 MRI 序列进行定性分类。使用多元线性回归，我们比较了 HIE 患者和对照组的海马 DTI 标测值。Spearman 相关性用于测试海马和丘脑区域 DTI 标测值之间的相关性。多元回归分析测试了 DTI 标测值与短期结局的相关性。
共纳入 55 例 HIE 新生儿（男性占 42%）和 13 例对照组（男性占 54%）。即使将 HIE 组限制为中度至重度损伤的患者（8 例），HIE 组和对照组的海马 DTI 标测值也相似。与对照组相比，中度至重度影响患者的丘脑 DTI 标测值明显降低（右侧部分各向异性分数[FA].148 比.182，P=0.01；左侧 FA.147 比.181，P=0.03）。海马和丘脑的 DTI 标测值相关（P<0.001）。海马 DTI 标测值与短期结局无关。
对 HIE 后新生儿海马进行定量 DTI 分析是一种可行的检查神经元损伤的技术。尽管 DTI 标测值在我们的队列中有助于识别丘脑损伤，但海马 DTI 分析并未提供关于 HIE 后海马损伤的额外信息。
