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Semi‐automated analysis of 4D flow MRI to assess the hemodynamic impact of intracranial atherosclerotic disease
Author(s) -
Vali Alireza,
Aristova Maria,
Vakil Parmede,
Abdalla Ramez,
Prabhakaran Shyam,
Markl Michael,
Ansari Sameer A.,
Schnell Susanne
Publication year - 2019
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.27747
Subject(s) - hemodynamics , icad , stenosis , medicine , cerebral blood flow , cardiology , blood flow , moyamoya disease , nuclear medicine , radiology , biochemistry , chemistry , gene
Purpose This study evaluated the feasibility of using 4D flow MRI and a semi‐automated analysis tool to assess the hemodynamic impact of intracranial atherosclerotic disease (ICAD). The ICAD impact was investigated by evaluating pressure drop (PD) at the atherosclerotic stenosis and changes in cerebral blood flow distribution in patients compared to healthy controls. Methods Dual‐venc 4D flow MRI was acquired in 25 healthy volunteers and 16 ICAD patients (ICA, N = 3; MCA, N = 13) with mild (<50%), moderate (50–69%), or severe (>70%) intracranial stenosis. A semi‐automated analysis tool was developed to quantify velocity and flow from 4D flow MRI and to evaluate cerebral blood flow redistribution. PD at stenosis was estimated using the Bernoulli equation. The PD calculation was examined by an in vitro phantom study against flow simulations. Results Flow analysis in controls indicated symmetry in blood flow rate (FR) and peak velocity (PV) between the brain hemispheres. For patients, PV in the affected hemisphere was significantly (65%) higher than the normal side ( P = 0.002). However, FR to both hemispheres of the brain was the same. The PD depicted significant correlation with PV asymmetry in patients ( ρ = 0.67 and P = 0.02), and it was significantly higher for severe compared to moderate stenosis (3.73 vs. 2.30 mm Hg, P = 0.02). Conclusion 4D flow MRI quantification enables assessment of the hemodynamic impact of ICAD. The significant difference of the PD between patients with severe and moderate stenosis and its correlation with PV asymmetry suggest that PD may be a pertinent hemodynamic biomarker to evaluate ICAD.