Medical Biophysics

Bradley MacIntosh PhD, University of Toronto
Associate Professor
Photo of Dr. Bradley MacIntosh
Contact Info
T: (416) 480-6100 x7277
F: (416) 480-5775
Website
Location
Sunnybrook Health Sciences Centre
2075 Bayview Avenue, Room A453
Toronto, ON, M4N 3M5
Research Interests
Biomedical Imaging, Cardiovascular Sciences, Neuroscience

At A Glance

In the MacIntosh lab we use brain imaging to study chronic diseases through a vascular lens with the goal of identifying new therapies. With the novel use of existing tools and development of new techniques we add to the current understanding of brain health, treatment, and recovery.  

Short Bio

Bradley MacIntosh is a Scientist at Sunnybrook Research Institute in the Brain Sciences research program & Physical Sciences platform, and a core member of the Heart and Stroke Foundation Canadian Partnership for Stroke Recovery. Brad holds an academic post as an Assistant Professor in the Department of Medical Biophysics at the University of Toronto, which is also where he completed his PhD in 2006. His MSc was at the Robarts Research Institute at Western University, supervised by Ravi Menon. After completing his postdoctoral fellowship at the University of Oxford’s Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), under the supervision of Professor Peter Jezzard, Brad returned to Toronto to take up his current post at the Sunnybrook Research Institute.

Research/Teaching

Research Synopsis

The MacIntosh lab focuses on developing and translating vascular imaging tools and measures to advance our understanding of human brain disease. Magnetic Resonance Imaging (MRI) is a versatile medical imaging modality and we work on functional imaging to study neurovascular function, cerebral blood flow, and related aspects of brain physiology.  

METHODS: Arterial Spin Labeling (ASL) MRI features prominently in our research activities. This technique produces non-invasive cerebral blood flow maps with spatial resolution that approaches the millimetre details of a conventional anatomical picture. Our ASL innovation includes image processing of individual scans, a pipeline to use these images in group analysis or multi-site trials, and additional ASL hemodynamic features (such as the arterial transit time and the spatial coefficient of variation). On-going efforts areusing deep learning to improve physiological MRI in radiology applications. 

CLINICAL MOTIVATION: The lab works on major burden of disease where vascular and physiological imaging can play a role to help patient. Active areas of research include stroke, small vessel disease, Alzheimer’s disease, and diabetes. The MacIntosh lab works closely with the Sunnybrook Centre for Youth Bipolar Disorder (CYBD); with ASL it is possible to map cerebral blood flow without ionizing radiation, which is particularly important in the developing brain. We also use aerobic exercise interventions to study brain adaption and changes with aerobic fitness. 

COLLABORATION: We focus on clinical translation and work closely with our Clinician-Scientist colleagues. The lab participates in numerous national and international initiatives (e.g. a national drug trial through the Canadian Partnership for Stroke Recovery, an international LeDucq Foundation international network to study perivascular spaces in small vessel disease, international collaborationsto use imaging to study psychiatric, diabetes, and stroke.  

Graduate Students

Sarah Atwi
Nicholas Luciw
Zahra Shirzadi

Publications and Awards

View PubMed search of this faculty member's recent publications.

Recent Publications

  • Theyers AE, et al., MacIntosh BJ. Cerebrovascular blood oxygenation level dependent pulsatility at baseline and following acute exercise among healthy adolescents. J Cereb Blood Flow Metab. 2018 Mar PubMed PMID: 29561225.
  • Robertson AD, et al., MacIntosh BJ. Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study. Front Aging Neurosci. 2017 Sep 29;9:318. PubMed PMID: 29033829.  
  • Mutsaerts HJ, et al., MacIntosh BJ. The spatial coefficient of variation in arterial spin labeling cerebral blood flow images. J CerebBlood Flow Metab. 2017 Sep;37(9):3184-3192. PubMed PMID:28058975.  
  • Swardfager W, MacIntosh BJ. Depression, Type 2 Diabetes, and Poststroke Cognitive Impairment. Neurorehabil Neural Repair. 2017 Jan;31(1):48-55. Epub 2016 Jun 29. PubMed PMID: 27364648.  
  • Atwi S, Shao H, Crane DE, da Costa L, Aviv RI, Mikulis DJ, Black SE, MacIntosh BJ. BOLD-based cerebrovascular reactivity vascular transfer function isolates amplitude and timing responses to better characterize cerebral small vessel disease. NMR Biomed. 2019 Mar;32(3):e4064. PubMed PMID: 30693582.  
  • Shirzadi Z, et al., MacIntosh BJ. Enhancement of automated blood flow estimates (ENABLE) from arterial spin-labeled MRI. J MagnReson Imaging. 2018 Mar;47(3):647-655. PubMed PMID: 28681479
  • Mutsaerts HJMM, et al., MacIntosh BJ; GENFI investigators. Comparison of arterial spin labeling registration strategies in the multi-center GENetic frontotemporal dementia initiative (GENFI). J Magn Reson Imaging. 2018 Jan;47(1):131-140. PubMed PMID: 28480617.

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