Identification of intra-individual variation in intracranial arterial flow by MRI and the effect on computed

Xinke Liu1,2, Evan Kao2, Henrik Haraldsson2

  • 1Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China.

Magma (New York, N.Y.)
|April 11, 2021
PubMed

Insights

Intra-individual flow variation in phase-contrast MRI can reach 10%, impacting hemodynamic simulations. This variation significantly alters wall shear stress but has minimal effect on low shear areas.

Area of Science:

  • Medical Imaging
  • Computational Fluid Dynamics
  • Biomedical Engineering

Background:

  • Accurate hemodynamic simulations are crucial for understanding cerebrovascular diseases.
  • Phase-contrast MRI (PC-MRI) is used to assess blood flow dynamics.
  • Intra-individual variability in serial PC-MRI studies can affect simulation accuracy.

Purpose of the Study:

  • To quantify intra-individual flow variation in serial 2D PC-MRI acquisitions.
  • To evaluate the impact of this flow variation on patient-specific computational fluid dynamics (CFD) simulations.
  • To determine the influence of flow variability on hemodynamic parameters, particularly wall shear stress.

Main Methods:

  • Prospective study of 51 patients with unruptured intracranial aneurysms undergoing serial 2D PC-MRI.
  • Flow and velocity parameters were extracted to assess reproducibility and variation.
  • Patient-specific CFD simulations were performed using measured inlet flow data.

Main Results:

  • Intraclass correlation coefficients for flow parameters ranged from 0.77 to 0.90, indicating good reproducibility.
  • A 10% coefficient of variation (CV) in mean flow was identified.
  • A 10% variation in inlet flow led to substantial changes in wall shear stress (up to 47.57%) but minor changes in low shear area (up to 2.79%).

Conclusions:

  • A 10% intra-individual mean flow variation is detectable with serial PC-MRI.
  • This flow variation introduces non-negligible alterations in calculated wall shear stress.
  • The impact on low shear area in hemodynamic calculations is relatively small.
Abstract