Amplified Flow Imaging (aFlow): A Novel MRI-Based Tool to Unravel the Coupled Dynamics between the Human Brain and Cerebrovasculature

Javid Abderezaei, John Martinez, Itamar Terem, Gloria Fabris, Aymeric Pionteck, Yang Yang, Samantha J. Holdsworth, Kambiz Nael, Mehmet Kurt

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


With each heartbeat, periodic variations in arterial blood pressure are transmitted along the vasculature, resulting in localized deformations of the arterial wall and its surrounding tissue. Quantification of such motions may help understand various cerebrovascular conditions, yet it has proven technically challenging thus far. We introduce a new image processing algorithm called amplified Flow (aFlow) which allows to study the coupled brain-blood flow motion by combining the amplification of cine and 4D flow MRI. By incorporating a modal analysis technique known as dynamic mode decomposition into the algorithm, aFlow is able to capture the characteristics of transient events present in the brain and arterial wall deformation. Validating aFlow, we tested it on phantom simulations mimicking arterial walls motion and observed that aFlow displays almost twice higher SNR than its predecessor amplified MRI (aMRI). We then applied aFlow to 4D flow and cine MRI datasets of 5 healthy subjects, finding high correlations between blood flow velocity and tissue deformation in selected brain regions, with correlation values r= 0.61, 0.59, 0.52 for the pons, frontal and occipital lobe (p < 0.001). Finally, we explored the potential diagnostic applicability of aFlow by studying intracranial aneurysm dynamics, which seems to be indicative of rupture risk. In two patients, aFlow successfully visualized the imperceptible aneurysm wall motion, additionally quantifying the increase in the high frequency wall displacement after a one-year follow-up period (20%, 76%). These preliminary data suggest that aFlow may provide a novel imaging biomarker for the assessment of aneurysms evolution, with important potential diagnostic implications.

Original languageEnglish (US)
Article number9153022
Pages (from-to)4113-4123
Number of pages11
JournalIEEE Transactions on Medical Imaging
Issue number12
StatePublished - Dec 2020


  • 4D flow MRI
  • Intracranial aneurysm
  • amplified MRI
  • aneurysm rupture
  • cine MRI

ASJC Scopus subject areas

  • Software
  • Radiological and Ultrasound Technology
  • Computer Science Applications
  • Electrical and Electronic Engineering

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