Purpose To examine the effect of low b‐values (0 < b 50 s/mm 2 ) on calculation intravoxel incoherent motion (IVIM) derived pseudodiffusion parameter in normal liver. Methods Simulations were performed to effects adding parameter. Low cumulatively added distribution and IVIM signal was generated with varying values. The fit model after addition Gaussian noise, simulated values compared true In addition, livers eight control subjects imaged using respiratory‐triggered DWI. Pseudodiffusion...

Introduction Cognitive symptoms are reported in the vast majority of individuals with long-COVID and there is growing support to suggest neurovascular mechanisms may play a role. Older adults at increased risk for developing complications associated COVID-19, including heightened cognitive decline. Cerebrovascular Reactivity (CVR), marker health, has been linked age related decline role long-COVID, however, this not yet explored. Methods The present study examined group differences CVR 31...

The cerebellum is known to be a relatively well preserved structure, but subtle alterations may occur early in the evolution of Alzheimer's disease (AD). Amnestic mild cognitive impairment (aMCI) patients appear particularly vulnerable AD. However, little currently whether altered patterns cerebellar function aMCI patients. 26 and 18 well-matched healthy controls underwent baseline resting-state functional magnetic resonance imaging (fMRI) scan. After mean follow-up period 20 months,...

Background Arterial spin labeling (ASL) can be confounded by varying arterial transit times (ATT) across the brain and with disease. Hadamard encoding schemes applied to 3D pseudocontinuous ASL (pCASL) acquire data multiple postlabeling delays (PLDs) estimate ATT then correct cerebral blood flow (CBF). Purpose To assess longitudinal reproducibility of pCASL Hadamard‐encoded PLDs. Study Type Prospective, longitudinal. Population Fifty‐two healthy, right‐handed male subjects who underwent...

Abstract Breath holding (BH) is a viable vasodilatory stimulus for calculating functional MRI-derived cerebral vascular reactivity (CVR). The BH technique suffers from reduced repeatability compared with gas inhalation techniques; however, extra equipment needed to perform techniques, and this not available at all institutions. This study aimed determine the sensitivity of activation CVR using multiband multi-echo simultaneous arterial spin labelling/blood oxygenation level dependent...

Abstract Resting‐state fMRI has shown the ability to predict task activation on an individual basis by using a general linear model (GLM) map resting‐state network features z ‐scores. The question remains whether relatively simplistic GLM is best approach accomplish this prediction. In study, several regression‐based machine‐learning approaches were compared, including GLMs, feed‐forward neural networks, and random forest bootstrap aggregation (bagging). data from 350 Human Connectome...

Recent advances in functional MRI techniques include multiband (MB) imaging and multi-echo (ME) imaging. In MB multiple slices are acquired simultaneously leading to significant increases temporal spatial resolution. Multi-echo enables echoes be one shot, where the ME images can used denoise BOLD time series increase sensitivity. this study, resting state fMRI (rs-fMRI) data were collected using a combined MBME sequence compared an single echo sequence. total, 29 subjects imaged, 18 of them...

A novel sequence has been introduced that combines multiband imaging with a multi-echo acquisition for simultaneous high spatial resolution pseudo-continuous arterial spin labeling (ASL) and blood-oxygenation-level dependent (BOLD) echo-planar (MBME ASL/BOLD). Resting-state connectivity in healthy adult subjects was assessed using this sequence. Four echoes were acquired acceleration of four, order to increase resolution, shorten repetition time, reduce slice-timing effects on the ASL...

Emerging evidence has shown that functional connectivity is dynamic and changes over the course of a scan. Furthermore, patterns can arise from short periods co-activation on order seconds. Recently, (CAPs) analysis was introduced to examine voxels resulting individual timepoints. The goal this study apply CAPs resting state fMRI data collected using an advanced multiband multi-echo (MBME) sequence, in comparison with (MB) sequence single echo. Data 28 healthy control subjects were examined....

Typical simultaneous blood oxygenation-level dependent (BOLD) and arterial spin labeling (ASL) sequences acquire two echoes, one perfusion-sensitive BOLD-sensitive. However, for ASL, spatial resolution brain coverage are limited due to the T1 decay of labeled blood. This study applies a sequence combining multiband acquisition with four echoes BOLD pseudo-continuous ASL (pCASL) echo planar imaging (MBME ASL/BOLD) block-design task-fMRI. A acceleration was employed increase reduce...

Background Blood oxygen level‐dependent (BOLD) functional MRI (fMRI) has been widely applied to detect brain activations. Recent advances in multiband (MB) and multiecho (ME) techniques have greatly improved fMRI methods. MB imaging improves temporal and/or spatial resolution, while ME shown improve BOLD sensitivity. This study aimed evaluate the novel MBME echo planar (EPI) sequence utilizing simultaneously determine if outperform single (MBSE) for task fMRI. Purpose To compare performance...

Blood oxygen level-dependent (BOLD) functional MRI (fMRI) is commonly used to measure cerebrovascular reactivity (CVR), which can convey insightful information about neurovascular health. Breath-holding (BH) has been shown be a practical vasodilatory stimulus for measuring CVR in clinical settings. The conventional BOLD fMRI approach some limitations, however, such as susceptibility-induced signal dropout at air tissue interfaces and low sensitivity especially areas of T2* . These drawbacks...

Receptor-enriched analysis of functional connectivity by targets (REACT) is a strategy to enrich MRI (fMRI) data with molecular information on the neurotransmitter distribution density in human brain, providing biological basis (FC) analysis. Although this approach has been used BOLD fMRI studies only so far, extending its use ASL imaging would provide many advantages, including more direct link neuronal activity compared and suitability for pharmacological assessing drug effects baseline...

Key Points Hemodialysis patients have impaired cerebrovascular reactivity. cerebral structural deficits. Background declines in blood flow (CBF) and oxygenation during hemodialysis that may lead to ischemic brain injury. Cerebrovascular reactivity (CVR) indicate which individuals are more susceptible intradialytic hypoperfusion ischemia. We hypothesized would decreased CVR increased CBF relative controls deficits be related Methods measured cortical thickness white matter hyperintensity...

Purpose To characterize the influence of perfusion on measurement diffusion changes over time when ADC is computed using standard two‐point methods. Materials and Methods Functional maps (FDMs), which depict in time, were compared with rCBV patients brain tumors. The FDMs created by coregistering subtracting from two points categorizing voxels where significantly increased (iADC), decreased (dADC), or did not change (ncADC). Traditional (tFDMs) b = 0,1000 s/mm 2 . Flow‐compensated (fcFDMs)...

Cerebrovascular health plays an important role in cognitive older adults. reactivity (CVR), a measure of cerebrovascular health, changes both normal and pathological aging, is increasingly being conceptualized as contributory to decline. Interrogation this process will yield new insights into correlates cognition neurodegeneration.The current study examines CVR using advanced MRI prodromal dementia states (amnestic non-amnestic mild impairment phenotypes; aMCI naMCI, respectively) adult...

Repetitive head impact exposure (RHIE) during contact sports (CS) might have potentially long-term neurological effects. We evaluated the effect of sport, time, and their interaction on local global functional connectivity density (FCD) as measured using an advanced multiband multi-echo EPI sequence in CS non-contact sport (NCS) middle school high athletes. Significant effects between time both FCD were detected, which suggest connections alterations due to participation.

Motivation: Long COVID in aging has become a significant public health concern, but the neurological mechanisms of symptoms remain elusive. Goal(s): This study aimed to assess abnormal brain perfusion related cognitive impairments COVID, who had initial non-hospitalized mild COVID-19.Approach: : 3D pCASL with Hadamard-encoded multiple PLDs was applied 30 elderly patients comparison 28 controls.Results: Both prolonged arterial transit time (ATT) and reduced ATT-corrected CBF (cerebral blood...

ABSTRACT Receptor-Enriched Analysis of functional Connectivity by Targets (REACT) is a novel analytical strategy that enriches connectivity (FC) information from MRI (fMRI) with molecular on the neurotransmitter distribution density in human brain, providing biological basis to FC analysis. So far, this integrative approach has been used blood oxygen level-dependent (BOLD) fMRI studies only, new insights into brain mechanisms underlying specific disorders and its response pharmacological...