Three-dimensional micro-structurally informed in silico myocardium—Towards virtual imaging trials in cardiac diffusion weighted MRI

Lashgari, Mojtaba; Ravikumar, Nishant; Teh, Irvin; Li, Jing-Rebecca; Buckley, David L.; Schneider, Jürgen; Frangi, Alejandro F.

doi:10.1016/j.media.2022.102592

Cited by 2 publications

(5 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Abnormalities of impulse propagation, arrhythmic tendency and hypertrophied myocardium have been linked to significant changes in gap junctions 52 . To study the sensitivity of the diffusion tensor to the presence of the ICD, results are compared for constant sarcolemma permeability with results for lowered ICD permeability 12 (

{\kappa}_{\mathrm{ICD}}

). Among all the sequences evaluated only STEAM shows changes in the diffusion tensor in response to reduced ICD permeability, as the spins diffuse further for larger

\Delta

and are more likely to collide with the cardiomyocyte end caps.…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, the link between a given change in microstructure and the corresponding change in DT-CMR parameters is not well established. The comprehension of this missing link between the MR image data and the microscopic structure lends itself to investigations using Monte Carlo (MC) random walk simulations [8][9][10] or finite element method (FEM) based simulators, 11,12 which have the power to elucidate the sensitivity of the DT-CMR signal to confounding factors or biological parameters present in the tissue microstructure. The first cardiac microstructure numerical phantom 8,9 utilized MC simulations and simplified cardiomyocytes to cylindrical geometries with differing hexagonal cross sections and lengths.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Realistic numerical simulations of diffusion tensor cardiovascular magnetic resonance: The effects of perfusion and membrane permeability

Alemany

Rose

Ferreira

et al. 2023

Magnetic Resonance in Med

View full text Add to dashboard Cite

Purpose To study the sensitivity of diffusion tensor cardiovascular magnetic resonance (DT‐CMR) to microvascular perfusion and changes in cell permeability. Methods Monte Carlo (MC) random walk simulations in the myocardium have been performed to simulate self‐diffusion of water molecules in histology‐based media with varying extracellular volume fraction (ECV) and permeable membranes. The effect of microvascular perfusion on simulations of the DT‐CMR signal has been incorporated by adding the contribution of particles traveling through an anisotropic capillary network to the diffusion signal. The simulations have been performed considering three pulse sequences with clinical gradient strengths: monopolar stimulated echo acquisition mode (STEAM), monopolar pulsed‐gradient spin echo (PGSE), and second‐order motion‐compensated spin echo (MCSE). Results Reducing ECV intensifies the diffusion restriction and incorporating membrane permeability reduces the anisotropy of the diffusion tensor. Widening the intercapillary velocity distribution results in increased measured diffusion along the cardiomyocytes long axis when the capillary networks are anisotropic. Perfusion amplifies the mean diffusivity for STEAM while the opposite is observed for short diffusion encoding time sequences (PGSE and MCSE). Conclusion The effect of perfusion on the measured diffusion tensor is reduced using an increased reference b‐value. Our results pave the way for characterization of the response of DT‐CMR to microstructural changes underlying cardiac pathology and highlight the higher sensitivity of STEAM to permeability and microvascular circulation due to its longer diffusion encoding time.

show abstract

{\kappa}_{\mathrm{ICD}}

). Among all the sequences evaluated only STEAM shows changes in the diffusion tensor in response to reduced ICD permeability, as the spins diffuse further for larger

\Delta

and are more likely to collide with the cardiomyocyte end caps.…”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Realistic numerical simulations of diffusion tensor cardiovascular magnetic resonance: The effects of perfusion and membrane permeability

Alemany

Rose

Ferreira

et al. 2023

Magnetic Resonance in Med

View full text Add to dashboard Cite

show abstract

“…The geometrical and physical characteristics of the virtual tissue models are adjusted according to the anatomical parameters of the heart tissue [26,47,30,27,48,28,29]. The diffusivity D controls simulated water molecule movement speed, the membrane permeability P controls passive diffusion probability, and the cellular volume fraction R ICS affects diffusivity differences between ICS and ECS.…”

Section: Virtual Tissue Modelsmentioning

confidence: 99%

“…The diffusivity D controls simulated water molecule movement speed, the membrane permeability P controls passive diffusion probability, and the cellular volume fraction R ICS affects diffusivity differences between ICS and ECS. Some virtual models consider heterogeneity in microstructure, such as myocyte diameter [26,28,27,48,29] and orientation [30,28,27,29], to match histological data statistics (Section 2.1.1).…”

Section: Virtual Tissue Modelsmentioning

confidence: 99%