Journal of neuroimaging : official journal of the American Society of Neuroimaging
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A substantial overlap exists between declines in cerebral vasoreactivity (CVR) and symptomatic Alzheimer's disease (AD). CVR can be quantified using transcranial Doppler (TCD) measurement of cerebral blood flow velocities (CBFV) in the middle cerebral artery (MCA) with CO2 as a vasodilatory stimulus. The breath-hold acceleration index (BHAI) is a new, more reliable measure of CVR developed recently in our laboratory. Our primary goal is to explore the possibility of using TCD for asymptomatic AD screening. ⋯ In this exploratory pilot study, CVR was significantly decreased in preclinical, prodromal, and mild AD subjects as compared to the healthy group. Lower CVR in the preclinical AD group was detected using the new BHAI index but not the conventional BHI index.
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Identifying a last known well (LKW) time surrogate for acute stroke is vital to increase stroke treatment. Diffusion-weighted imaging (DWI) signal intensity initially increases from onset of stroke but mapping a reliable time course to the signal intensity has not been demonstrated. ⋯ There is good correlation between DWI intensity and minutes from onset to MRI. This suggests a time-dependent DWI intensity response and supports the potential use of DWI intensity measurements to extrapolate an LKW time. Further studies are being pursued to increase both experience and generalizability.
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We hypothesized that vessel wall MR imaging (VWI) with 3D-time-of-flight magnetic resonance imaging (3D-TOF-MRA) together increases the ability to detect abnormal intracranial vessel segments compared to 3D-TOF-MRA alone. ⋯ 3D-TOF-MRA and VWI together identifies a higher number of abnormal vessel segments than 3D-TOF-MRA alone and may provide a more accurate assessment of disease burden.
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Structure-by-structure analysis, in which the brain magnetic resonance imaging (MRI) is parcellated based on its anatomical units, is widely used to investigate chronological changes in morphology or signal intensity during normal development, as well as to identify the alterations seen in various diseases or conditions. The multi-atlas label fusion (MALF) method is considered a highly accurate parcellation approach, and anticipated for clinical application to quantitatively evaluate early developmental processes. However, the current MALF methods, which are designed for neonatal brain segmentations, are not widely available. ⋯ The Web platform by braingps.mricloud.org will eliminate the dependence on a particular operating system (eg, Windows, Macintosh, or Linux) and the requirement for high computational performance of the user's computers. The MALF-based, fully automated, image parcellation could achieve excellent agreement with manual parcellation, and the whole and regional brain volumes quantified through this method demonstrated developmental trajectories comparable to those from a previous publication. This solution will make the latest MALF tools readily available to users, with minimum barriers, and will expedite and accelerate advancements in developmental neuroscience research, neonatology, and pediatric neuroradiology.
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Capabilities of CTA for evaluation of intracranial aneurysms treated with the Woven EndoBridge (WEB) system has not been thoroughly studied yet. Our aim is to compare the ability of CTA to that of DSA to depict the occlusion status of aneurysms treated with WEB device and present the level of reproducibility of results from CTA. ⋯ CTA is a reliable and reproducible method to evaluate the aneurysm occlusion status and could be implemented on the follow-up of aneurysms treated with WEB.