Diffusion Tensor is Rats with Cerebral Hemispheric Infarct

弥散张量是患有脑半球梗塞的大鼠

• 批准号: 10670827
• 负责人: MINAMI Manabu
• 金额: $ 2.18万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670827/
• 关键词: magnetic resonance imaging; diffusion weighted imaging; diffusion tensor; arebral intact

<Introduction>cerebral vascular disorder is one of the most fatal diseases despite current advances in medical science. Acute cerebral infarction causes a long-term, serious sequelae because of lack of any established therapy to treat this disorder. In the diagnosis of acute cerebral ischemia, it is important to understand the extent of reversible ischemic penumbra, to distinguish it from unsalvageable infarcted tissues, and to determine appropriate therapies. However, methods that enable non-invasive observation of pathophysiologic state of the affected brain tissue have been limited. The measurement of random diffusional motion of water molecules in the human CNS is of great interest because it provides early alteration of CNS injury. In human brain, the diffusional motion of water is impeded by tissue structure such as cell membranes, myelin sheaths and white matter fiber tracts. The purpose of the present study was to clarify precise diffusion properties of water during early focal … More , cerebral ischemia using diffusion tensor analysis at a 7-tesla magnet.<Material and Method> we studied 8 Wistar rats (250-350g, in body weight) for control and 10 with hemispheric infarct. All experiments were performed using a 7.05 T horizontal spectrometer (UNITY plus-SIS 300/183, Varian) equipped with an actively shielded gradient up to 120 mT/m per axis using a quadrature coil, 38mm in inner diameter. We used diffusion weighted spin-echo sequences (TR/TE = 3000/40msec, Δ/δ = 19/12lmsec, 2mm slice thickness, FOV=3x3cmィイD12ィエD1, NEX = 2, 256xl28 pixel matrix, gradient strength = 6gauss/cm per axis) for diffusion tensor analysis. Diffusion gradients (b-value of 557 s/mmィイD12ィエD1 per axis) were always applied on two axes simultaneously around the 180° pulse. Diffusion properties were measured along 6 noncollinear directions : (Gx, Gy, Gz) = [(0, 0. 0), (1, 0, 1), (-1, 0, 1), (0, 1, 1), (0, 1, -1), (1, 1, 0), (1, -1, 0)]. The six elements of the diffusion tensor D were estimated in each voxel using multivariate regression, and the eigenvalues (λ) were determined. Maps of Trace (D)/3 (ADC), and the fractional anisotropy (FA) were generated on a voxel-by-voxel basis. Values for ADC, and FA were determined in regions of gray and white matter, and basal ganglia in both hemispheres.<Results> The measured ADC and FA values of distilled water were 2.10±0.04x10ィイD1-3ィエD1mmィイD12ィエD1/s and 0.06±0.029. The ADC and FA values in 8 normal rats were as follows, right gray matter 0.76±0.15 (mean ± standard deviation x 10ィイD1-3ィエD1mmィイD12ィエD1/s), 0.38±0.18 (mean ± standard deviation), left gray matter 0.73±0.17, 0.35±0.16, right white matter 0.72±0.14, 0.52±0.13, left white matter 0.74±0.13, 0.55±0.15, right basal ganglia 0.72±0.12, 0.32±0.15, left basal ganglia 0.75±0.13, 0.37±0.18. Comparisons of ADC and FA between the left and right hemisphere demonstrated no statistically significant difference in controls. For FA, the difference between gray matter and white matter and between basal ganglia and white matter were significant. The ADC and FA values in 10 rats with hemispheric infarct were as follows, right gray matter 0.73±0.16, 0.36±0.17, left gray matter 0.48±0.21, 0.38±0.18, right white matter 0.75±0.18. 0.51±0.18, left white matter 0.55±0.19, 0.45±0.22, right basal ganglia 0.73±0.12, 0.37±0.15, left basal ganglia 0.44±0.22, 0.35±0.19, A11 ADC values in the ischemic hemisphere were statistically lower than those in the contralateral hemisphere. FA in the ischemic white matter was also significantly lower than that in the contralateral hemisphere.<Conclusion> This study suggests that diffusion tensor analysis may be robust enough to perceive changes in diffusion properties of ischemic neuronal tissue. Further data from much larger materials and human patients are required to validate this method. Less

<Introduction>脑血管疾病是最致命的疾病之一，尽管目前医学科学取得了进步。急性脑梗死会导致长期的严重后遗症，因为缺乏任何既定的治疗方法来治疗这种疾病。在急性脑缺血的诊断中，了解可逆性缺血半暗带的程度，将其与无法挽救的梗死组织区分开来，并确定适当的治疗方法是很重要的。然而，能够非侵入性地观察受影响的脑组织的病理生理状态的方法受到限制。测量人中枢神经系统中水分子的随机扩散运动是非常有意义的，因为它提供了中枢神经系统损伤的早期改变。在人脑中，水的扩散运动受到诸如细胞膜、髓鞘和白色物质纤维束的组织结构的阻碍。本研究的目的是澄清在早期的焦点水的精确扩散特性 ...更多信息 ，在7特斯拉磁体上使用扩散张量分析的脑缺血。<Material and Method>本实验选用8只Wistar大鼠（体重250- 350 g）作为对照组，10只大鼠为脑梗死组。所有实验均使用7.05 T水平光谱仪（UNITY plus-SIS 300/183，Varian）进行，该光谱仪配备有使用内径为38 mm的正交线圈的每轴高达120 mT/m的主动屏蔽梯度。我们使用弥散加权自旋回波序列（TR/TE = 3000/40 msec，Δ/δ = 19/12 lmsec，2 mm层厚，FOV= 3x 3cm D12 D12，NEX = 2，256 x128像素矩阵，梯度强度= 6高斯/cm/轴）进行弥散张量分析。始终在180°脉冲周围的两个轴上同时施加扩散梯度（每个轴的b值为557 s/mm × D12 × D1）。沿沿着6个非共线方向测量扩散特性：（Gx，戈伊，Gz）= [（0，0. 0），（1，0，1），（-1，0，1），（0，1，1），（0，1，-1），（1，1，0），（1，-1，0）]。使用多元回归在每个体素中估计扩散张量D的六个元素，并确定特征值（λ）。逐体素生成迹线（D）/3（ADC）和各向异性分数（FA）图。在两个半球的灰质和白色物质以及基底节区测定ADC值和FA值。<Results>测得蒸馏水的ADC值和FA值分别为2.10± 0.04 × 10 ~（-1）D1-3 × 10 ~（-1）D1 mm × 10 ~（-1）D12 × 10 ~（-1）D1/s和0.06±0.029。8只正常大鼠的ADC值和FA值分别为：右侧灰质0.76±0.15（平均值±标准差x 10 mm D1-3 mm D12 mm D1/s），0.38±0.18（平均值±标准差），左侧灰质0.73±0.17，0.35±0.16，右侧白色质0.72±0.14，0.52±0.13，左侧白色质0.74±0.13，0.55±0.15，右侧基底节0.72±0.12，0.32±0.15，左侧基底节0.75±0.13，0.37±0.18。对照组左右半球ADC值和FA值无显著性差异。灰质与白色质、基底节与白色质FA差异有显著性。10只脑梗死大鼠的ADC值和FA值分别为：右侧灰质0.73±0.16，0.36±0.17，左侧灰质0.48±0.21，0.38±0.18，右侧白色物质0.75±0.18。缺血侧大脑半球的ADC值分别为0.51±0.18，左侧白色物质0.55±0.19，0.45±0.22，右侧基底节区0.73 ±0.12，0.37±0.15，左侧基底节区0.44±0.22，0.35±0.19，A11的ADC值明显低于对侧大脑半球。缺血侧白色物质的FA也明显低于对侧半球。<Conclusion>这项研究表明，扩散张量分析可能是强大的，足以感知缺血神经元组织的扩散特性的变化。需要来自更大材料和人类患者的进一步数据来验证这种方法。少

项目成果

Abe O, et al: "Diffusion Weighted Imaging"Japanese Journal of Diagnostic Imaging. 19(10). 154-163 (1999)

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阿部 修 他: "拡散画像"画像診断. 19(10). 1154-1163 (1999)

Osamu Abe 等人：“扩散成像”诊断成像 19(10) 1154-1163 (1999)。