Technical note: use of a double inversion recovery pulse sequence to image selectively grey or white brain matter.
ABSTRACT The design of a double inversion recovery (DIR) sequence, to image selectively grey or white brain matter, is described. Suitable choice of inversion times allows either cerebrospinal fluid (CSF) and white matter to be suppressed, to image the cortex alone, or CSF and grey matter to be suppressed, to image the white matter. The DIR sequence was found to give clear delineation of the cerebral cortex.
- SourceAvailable from: Paul Polak
Conference Paper: 3D DIR: 3D Double Inversion Recovery in Multiple SclerosisInternation Society of Magnetic Resonance in Medicine; 05/2011
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ABSTRACT: Many of the regions with the earliest atrophy in Alzheimer's Disease (AD) do not show prominent deficits on functional imaging studies of flow or metabolism. This paradox may provide unique insights into the pathophysiology of AD. We sought to examine the relationship between function and atrophy in AD using MRI blood flow and anatomic imaging. 22 subjects diagnosed with AD, mean Mini Mental State Exam (MMSE) score 22.2, and 16 healthy elderly controls were imaged with a volumetric arterial spin labeling blood flow MRI technique and an anatomical imaging method using the identical spatial resolution, image orientation, and spatial encoding strategy. Cerebral blood flow (CBF) and gray matter (GM) maps derived from the imaging were transformed to a standard anatomical space. GM and CBF maps were tested for significant differences between groups. Additionally, images were tested for regions with significant mismatch of the CBF and GM differences between groups. CBF was significantly lower in the bilateral precuneus, parietal association cortex and the left inferior temporal lobe but was non-significantly increased in the hippocampus and other medial temporal structures. After correction for GM loss, CBF was significantly elevated in the hippocampus and other medial temporal structures. The hippocampus and other regions affected early in AD are characterized by elevated atrophy-corrected perfusion per cm(3) of tissue. This suggests compensatory or pathological elevation of neural activity, inflammation, or elevated production of vasodilators.NeuroImage 07/2008; 42(4):1267-74. · 6.25 Impact Factor
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ABSTRACT: The efficacy of stereotactic neurosurgery procedures is critically dependent on the accuracy of the device placement procedure. The first step in this process involves correctly identifying the target location in three-dimensional brain space. In some clinical applications, this targeting process cannot be accomplished using MRI images of gross anatomical structures alone. The amygdala complex is a case in point, in that it consists of multiple histologically defined subnuclei with different functional characteristics. In this report, we describe an elastic atlas brain-morphing method that projects amygdala subnuclear anatomical information onto the MRI volumes of individual subjects. The accuracy of this method was tested in 5 representative subjects using quantitative image-matching analytical techniques. The results demonstrate a high degree of intersubject variability in medial temporal lobe anatomy, and markedly superior anatomical matching performance by the elastic morphing method compared to Affine transformation. Nonlinear elastic morphing technique provides superior performance on fitting atlas templates to individual brain. The strengths and limitations of this and other atlas morphing methods are discussed in the context of emerging functional neurosurgery applications.Stereotactic and Functional Neurosurgery 07/2009; 87(4):219-28. · 1.46 Impact Factor