A5085398611- Advanced MRI Techniques and Applications
- Advanced Neuroimaging Techniques and Applications
- Cerebrovascular and Carotid Artery Diseases
- MRI in cancer diagnosis
- Acute Ischemic Stroke Management
- Medical Imaging Techniques and Applications
- Cardiac Imaging and Diagnostics
- Dementia and Cognitive Impairment Research
- Intracerebral and Subarachnoid Hemorrhage Research
- Medical Image Segmentation Techniques
- Neurological Disease Mechanisms and Treatments
- Functional Brain Connectivity Studies
- Brain Tumor Detection and Classification
- Alzheimer's disease research and treatments
- Amyotrophic Lateral Sclerosis Research
- Atomic and Subatomic Physics Research
- Medical Imaging and Analysis
- Radiomics and Machine Learning in Medical Imaging
- Traumatic Brain Injury and Neurovascular Disturbances
- Cardiovascular Health and Disease Prevention
- Parkinson's Disease Mechanisms and Treatments
- Photoacoustic and Ultrasonic Imaging
- NMR spectroscopy and applications
- Intracranial Aneurysms: Treatment and Complications
- Advanced Neural Network Applications
Foothills Medical Centre
2016-2025
University of Calgary
2016-2025
Alberta Health Services
2015-2024
Alberta Children's Hospital
2024
Landscape Research Group
2023
Authorised Association Consortium
2023
University of Alberta
2019-2022
Allen Institute for Brain Science
2007-2022
Resonance Research (United States)
2011-2022
Women and Children’s Health Research Institute
2022
An MR angiographic technique, referred to as 3D TRICKS (3D time-resolved imaging of contrast kinetics) has been developed. This technique combines and extends several previously published elements. These elements include an increased sampling rate for lower spatial frequencies, temporal interpolation k-space views, zero-filling in the slice-encoding dimension. When appropriately combined, these permit reconstruction a series image sets having effective frame one volume every 2-6 s. Acquiring...
Background and Purpose— We investigated the sensitivity reliability of MRI susceptibility-weighted imaging (SWI) compared with routine T2*-weighted gradient-recalled echo (GRE) for cerebral microbleed (CMB) detection. Methods— used data from a prospective study amyloid angiopathy (n=9; mean age, 71±8.3) healthy non–cerebral controls (n=22; 68±6.3). Three raters (labeled 1, 2, 3) independently interpreted GRE SWI sequences (using phase-filtered magnitude image) blinded to clinical...
Knowledge of human blood-flow waveforms is required for in vitro investigations and numerical modelling. Parameters interest include: velocity flow waveform shapes, inter- intra-subject variability frequency content. We characterized the blood-velocity left right common carotid arteries (CCAs) 17 normal volunteers (24 to 34 years), analysing 3560 cardiac cycles total. Instantaneous peak-velocity (Vpeak) measurements were obtained using pulsed-Doppler ultrasound with simultaneous collection...
MR imaging at very high field (3.0 T) is a significant new clinical tool in the modern neuroradiological armamentarium. In this report, we summarize our 40-month experience performing examinations 3.0 T and review relevant technical issues. We report on these issues and, where appropriate, their solutions. Issues examined include: increased SNR, larger chemical shifts, additional problems associated with installation of scanners, challenges designing obtaining appropriate coils, greater...
Decline in cognitive function begins by the 40s, and may be related to future dementia risk. We used data from a community-representative study determine whether there are age-related differences simple gait tests these were associated with covert cerebrovascular disease on magnetic resonance imaging (MRI).Between 2010 2012, 803 participants aged 40 75 years Prospective Urban Rural Epidemiological (PURE) study, recruited prespecified postal code regions centered 4 Canadian cities, underwent...
Examining the frequency content of signals is critical in many applications, from neuroscience to astronomy. Many techniques have been proposed accomplish this. One these, S-transform, provides simultaneous time and information similar wavelet transform, but uses sinusoidal basis functions produce globally referenced phase measurements. It has shown promise medical imaging applications high computational requirements. This paper presents a general transform that describes Fourier-family...
We used functional MRI (fMRI), transcranial Doppler ultrasound, and visual evoked potentials (VEPs) to determine the nature of blood flow responses brain activity carbon dioxide (CO2) inhalation in patients with cerebral amyloid angiopathy (CAA), their association markers CAA severity.In a cross-sectional prospective cohort study, fMRI, ultrasound CO2 reactivity, VEP data were compared between 18 probable (by Boston criteria) healthy controls, matched by sex age. Functional consisted task...
Background and Purpose— Among patients with acute ischemic stroke, we determine computed tomographic perfusion (CTP) thresholds associated follow-up infarction at different stroke onset-to-CTP CTP-to-reperfusion times. Methods— Acute occlusion on angiography were acutely imaged CTP. Noncontrast tomography magnectic resonance diffusion–weighted imaging between 24 48 hours used to delineate infarction. Reperfusion was assessed conventional angiogram or 4-hour repeat angiography. T max ,...
Autopsy studies suggest that cerebral amyloid angiopathy (CAA) is associated with cognitive impairment and risk for dementia. We analyzed neuropsychological test data from a prospective cohort study of patients CAA to identify the prevalence its associations brain magnetic resonance imaging features apolipoprotein E genotype.Data were 34 CAA, 16 Alzheimer's disease, 69 mild impairment, 27 ischemic stroke participants. Neuropsychological results expressed as z scores in relation normative...
The purpose of this study was to investigate whether low cerebral blood flow (CBF) is associated with subsequent development white matter hyperintensities (WMH). Patients were included from a longitudinal magnetic resonance (MR) imaging minor stroke/transient ischemic attack patients. Images co-registered and new WMH at 18 months identified by comparing follow-up baseline fluid-attenuated inversion recovery (FLAIR). Regions-of-interest (ROIs) placed on FLAIR images in one three categories:...
To compare the diagnostic accuracy of time-resolved three-dimensional contrast material-enhanced magnetic resonance (MR) angiography with that conventional for imaging lower extremity vasculature.Sixty-nine patients who were evaluated possible surgical intervention underwent (ie, digital subtraction [DSA]) and contrast-enhanced MR kinetics [TRICKS]). Two independent, blinded readers vessel stenosis occlusion at DSA angiographic image readings. Sensitivity, specificity, positive negative...
Definitions for chronic lacunar infarcts vary. Recent retrospective studies suggest that many acute strokes do not develop a cavitated appearance. We determined the characteristics of on follow-up MRI in consecutive patients participating prospective research studies.Patients with infarction diffusion-weighted imaging were selected from 3 cohort minor stroke imaged within <24 hours onset. Follow-up was performed at 30 days (Vascular Imaging Acute Stroke Identifying Predictors Clinical...
Background Volume measurements of intracerebral haemorrhage are prognostically important and increasingly used in clinical trials to measure the effects potential interventions. The purpose this work is establish reliability haematoma volume obtained using a computer-assisted method called Quantomo (for quantitative tomography) ABC/2 method. Hypothesis reliably detects smaller changes as compared with because tailored geometry individual volumes whereas approximates all ellipsoids. Methods...
Multisite longitudinal neuroimaging designs are used to identify differential brain structural change associated with onset or progression of disease. The reliability neuroanatomical measurements over time and across sites is a crucial aspect power in such studies. Prior work has found that while within-site reliabilities excellent, between-site generally more modest. Factors may increase include standardization scanner platform sequence parameters correction for between-scanner variations...
Decreasing magnetic resonance (MR) image acquisition times can potentially make MR examinations more accessible. Compressed sensing (CS)-based reconstruction methods decrease time by reconstructing high-quality images from data that were originally sampled at rates inferior to the Nyquist-Shannon sampling theorem. Deep-learning have been used solve CS problem. These proposed are able quickly reconstruct in a single pass using an appropriately trained network. A variety of different network...
<h3>Objective</h3> To evaluate progressive white matter (WM) degeneration in amyotrophic lateral sclerosis (ALS). <h3>Methods</h3> Sixty-six patients with ALS and 43 healthy controls were enrolled a prospective, longitudinal, multicenter study the Canadian Neuroimaging Consortium (CALSNIC). Participants underwent harmonized neuroimaging protocol across 4 centers that included diffusion tensor imaging (DTI) for assessment of WM integrity. Three visits accompanied by clinical assessments...