Electron Density and Effective Atomic Number of Normal-Appearing Adult Brain Tissues: Age-Related Changes and Correlation with Myelin Content.

IF 2.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Tomography Pub Date : 2025-08-25 DOI:10.3390/tomography11090095

Tomohito Hasegawa, Masanori Nakajo, Misaki Gohara, Kiyohisa Kamimura, Tsubasa Nakano, Junki Kamizono, Koji Takumi, Fumitaka Ejima, Gregor Pahn, Eran Langzam, Ryota Nakanosono, Ryoji Yamagishi, Fumiko Kanzaki, Takashi Yoshiura

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引用次数: 0

Abstract

Objectives: Few studies have reported in vivo measurements of electron density (ED) and effective atomic number (Z_eff) in normal brain tissue. To address this gap, dual-energy computed tomography (DECT)-derived ED and Z_eff maps were used to characterize normal-appearing adult brain tissues, evaluate age-related changes, and investigate correlations with myelin partial volume (V_my) from synthetic magnetic resonance imaging (MRI). Materials and Methods: Thirty patients were retrospectively analyzed. The conventional computed tomography (CT) value (CT_conv), ED, Z_eff, and V_my were measured in the normal-appearing gray matter (GM) and white matter (WM) regions of interest. V_my and DECT-derived parameters were compared between WM and GM. Correlations between V_my and DECT parameters and between age and DECT parameters were analyzed. Results: V_my was significantly greater in WM than in GM, whereas CT_conv, ED, and Z_eff were significantly lower in WM than in GM (all p < 0.001). Z_eff exhibited a stronger negative correlation with V_my (ρ = -0.756) than CT_conv (ρ = -0.705) or ED (ρ = -0.491). ED exhibited weak to moderate negative correlations with age in nine of the 14 regions. In contrast, Z_eff exhibited weak to moderate positive correlations with age in nine of the 14 regions. CT_conv exhibited negligible to insignificant correlations with age: Conclusions: This study revealed distinct GM-WM differences in ED and Z_eff along with opposing age-related changes in these quantities. Therefore, myelin may have substantially contributed to the lower Z_eff observed in WM, which underlies the GM-WM contrast observed on non-contrast-enhanced CT.

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正常成人脑组织的电子密度和有效原子序数：年龄相关变化及其与髓磷脂含量的相关性。

目的：正常脑组织中电子密度（ED）和有效原子序数（Zeff）的体内测量研究很少。为了解决这一差距，双能计算机断层扫描（DECT）衍生的ED和Zeff图被用来表征正常的成人脑组织，评估年龄相关的变化，并研究合成磁共振成像（MRI）与髓磷脂部分体积（Vmy）的相关性。材料与方法：对30例患者进行回顾性分析。在感兴趣的正常灰质（GM）和白质（WM）区域测量常规计算机断层扫描（CT）值（CTconv）、ED、Zeff和Vmy。比较WM和GM的Vmy和DECT衍生参数，分析Vmy与DECT参数、年龄与DECT参数之间的相关性。结果：WM组Vmy显著高于GM组，CTconv、ED、Zeff显著低于GM组（均p < 0.001）。与CTconv （ρ = -0.705）或ED （ρ = -0.491）相比，Zeff与Vmy （ρ = -0.756）表现出更强的负相关。ED在14个地区中的9个与年龄呈弱至中度负相关。相比之下，Zeff在14个区域中的9个与年龄表现出弱到中度的正相关。CTconv与年龄的相关性可以忽略不计。结论：本研究揭示了ED和Zeff中GM-WM的明显差异，以及这些数量与年龄相关的相反变化。因此，髓磷脂可能在很大程度上促成了WM中观察到的较低的Zeff，这是在非增强CT上观察到的GM-WM对比的基础。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Tomography Medicine-Radiology, Nuclear Medicine and Imaging

CiteScore

2.70

自引率

10.50%

发文量

222

期刊介绍： TomographyTM publishes basic (technical and pre-clinical) and clinical scientific articles which involve the advancement of imaging technologies. Tomography encompasses studies that use single or multiple imaging modalities including for example CT, US, PET, SPECT, MR and hyperpolarization technologies, as well as optical modalities (i.e. bioluminescence, photoacoustic, endomicroscopy, fiber optic imaging and optical computed tomography) in basic sciences, engineering, preclinical and clinical medicine. Tomography also welcomes studies involving exploration and refinement of contrast mechanisms and image-derived metrics within and across modalities toward the development of novel imaging probes for image-based feedback and intervention. The use of imaging in biology and medicine provides unparalleled opportunities to noninvasively interrogate tissues to obtain real-time dynamic and quantitative information required for diagnosis and response to interventions and to follow evolving pathological conditions. As multi-modal studies and the complexities of imaging technologies themselves are ever increasing to provide advanced information to scientists and clinicians. Tomography provides a unique publication venue allowing investigators the opportunity to more precisely communicate integrated findings related to the diverse and heterogeneous features associated with underlying anatomical, physiological, functional, metabolic and molecular genetic activities of normal and diseased tissue. Thus Tomography publishes peer-reviewed articles which involve the broad use of imaging of any tissue and disease type including both preclinical and clinical investigations. In addition, hardware/software along with chemical and molecular probe advances are welcome as they are deemed to significantly contribute towards the long-term goal of improving the overall impact of imaging on scientific and clinical discovery.