Bradbury Allison, Peterson David, Vite Charles, Chen Steven, Ellinwood N Matthew, Provenzale James
Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, USA
Department of Radiology, Duke University Medical Center, USA.
Neuroradiol J. 2016 Dec;29(6):417-424. doi: 10.1177/1971400916665378. Epub 2016 Sep 27.
The goal of this study was to compare the diffusion tensor imaging (DTI) metrics from an end-stage canine Krabbe brain evaluated by MR imaging ex vivo to those of a normal dog brain. We hypothesized that the white matter of the canine Krabbe brain would show decreased fractional anisotropy (FA) values and increased apparent diffusion coefficient (ADC) and radial diffusivity (RD) values.
An 11-week-old Krabbe dog was euthanized after disease progression. The brain was removed and was placed in a solution of 10% formalin. MR imaging was performed and compared to the brain images of a normal dog that was similarly fixed post-mortem. Both brains were scanned using similar protocols on a 7 T small-animal MRI system. For each brain, maps of ADC, FA, and RD were calculated for 11 white-matter regions and five control gray-matter regions.
Large decreases in FA values, increases in ADC values, and increases in RD (consistent with demyelination) values, were seen in white matter of the Krabbe brain but not gray matter. ADC values in gray matter of the Krabbe brain were decreased by approximately 29% but increased by approximately 3.6% in white matter of the Krabbe brain. FA values in gray matter were decreased by approximately 3.3% but decreased by approximately 29% in white matter. RD values were decreased by approximately 27.2% in gray matter but increased by approximately 20% in white matter.
We found substantial abnormalities of FA, ADC, and RD values in an ex vivo canine Krabbe brain.
本研究的目的是比较通过离体磁共振成像评估的终末期犬类克拉伯病脑的扩散张量成像（DTI）指标与正常犬脑的指标。我们假设犬类克拉伯病脑的白质将显示分数各向异性（FA）值降低，表观扩散系数（ADC）和径向扩散率（RD）值升高。
一只11周龄的患有克拉伯病的犬在疾病进展后实施安乐死。取出大脑并置于10%的福尔马林溶液中。进行磁共振成像，并与死后同样固定的正常犬脑图像进行比较。在一台7T小动物磁共振成像系统上，使用相似的方案对两个大脑进行扫描。对于每个大脑，计算11个白质区域和5个对照灰质区域的ADC、FA和RD图。
在克拉伯病脑的白质中观察到FA值大幅降低、ADC值升高以及RD（与脱髓鞘一致）值升高，但灰质中未出现这种情况。克拉伯病脑灰质中的ADC值降低了约29%，但白质中的ADC值升高了约3.6%。灰质中的FA值降低了约3.3%，但白质中的FA值降低了约29%。灰质中的RD值降低了约27.2%，但白质中的RD值升高了约20%。
我们在离体犬类克拉伯病脑中发现了FA、ADC和RD值的显著异常。
