Abstract:
Ultra-high contrast (UHC) MRI describes forms of MRI in which little or no contrast is seen on conventional MRI images but very high contrast is seen with UHC techniques. One of these techniques uses the divided subtracted inversion recovery (dSIR) sequence, which, in modelling studies, can produce ten times the contrast of conventional inversion recovery (IR) sequences. When used in cases of mild traumatic brain injury (mTBI), the dSIR sequence frequently shows extensive abnormalities in white matter that appears normal when imaged with conventional T2-fluid-attenuated IR (T2-FLAIR) sequences. The changes are bilateral and symmetrical in white matter of the cerebral and cerebellar hemispheres. They partially spare the anterior and posterior central corpus callosum and peripheral white matter of the cerebral hemispheres and are described as the whiteout sign. In addition to mTBI, the whiteout sign has also been seen in methamphetamine use disorder and Grinker\'s myelinopathy (delayed post-hypoxic leukoencephalopathy) in the absence of abnormalities on T2-FLAIR images, and is a central component of post-insult leukoencephalopathy syndromes. This paper describes the concept of ultra-high contrast MRI, the whiteout sign, the theory underlying the use of dSIR sequences and post-insult leukoencephalopathy syndromes.
摘要:
超高对比度(UHC)MRI描述了MRI的形式,其中在常规MRI图像上看到很少或没有对比度,但是使用UHC技术看到非常高的对比度。这些技术中的一种使用划分的相减反演恢复(dSIR)序列,which,在建模研究中,可以产生十倍的对比度常规反转恢复(IR)序列。当用于轻度创伤性脑损伤(mTBI)的情况下,dSIR序列经常在白质中显示广泛的异常,当使用常规T2液体衰减IR(T2-FLAIR)序列成像时,这些异常看起来正常。大脑和小脑半球白质的变化是双侧和对称的。它们部分保留了大脑半球的中央call体前后和周围白质,并被描述为白斑体征。除了mTBI,在T2-FLAIR图像上没有异常的情况下,甲基苯丙胺使用障碍和Grinker髓鞘病(迟发性缺氧后白质脑病)也出现了白斑迹象,并且是侮辱后白质脑病综合征的中心组成部分。本文介绍了超高对比度MRI的概念,白色标志,使用dSIR序列和损伤后白质脑病综合征的基础理论。