MRI Simulation Study Investigating Effects of Vessel Topology, Diffusion, and Susceptibility on Transverse Relaxation Rates Using a Cylinder Fork Model

Mohammed Salman Shazeeb, Jayashree Kalpathy-Cramer, Bashar Issa

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Brain vasculature is conventionally represented as straight cylinders when simulating blood oxygenation level dependent (BOLD) contrast effects in functional magnetic resonance imaging (fMRI). In reality, the vasculature is more complicated with branching and coiling especially in tumors. Diffusion and susceptibility changes can also introduce variations in the relaxation mechanisms within tumors. This study introduces a simple cylinder fork model (CFM) and investigates the effects of vessel topology, diffusion, and susceptibility on the transverse relaxation rates R2∗and R2. Simulations using Monte Carlo methods were performed to quantify R2∗and R2 by manipulating the CFM at different orientations, bifurcation angles, and rotation angles. Other parameters of the CFM were chosen based on physiologically relevant values: vessel diameters (∼2-10 μm), diffusion rates (1 × 10-11-1 × 10-9 m2/s), and susceptibility values (3 × 10-8-4 × 10-7 cgs units). R2∗and R2 measurements showed a significant dependence on the bifurcation and rotation angles in several scenarios using different vessel diameters, orientations, diffusion rates, and susceptibility values. The angular dependence of R2∗and R2 using the CFM could potentially be exploited as a tool to differentiate between normal and tumor vessels. The CFM can also serve as the elementary building block to simulate a capillary network reflecting realistic topological features.

Original languageEnglish (US)
Article number15968
JournalScientific Reports
Volume7
Issue number1
DOIs
StatePublished - Dec 1 2017
Externally publishedYes

Fingerprint

Monte Carlo Method
Neoplasms
Magnetic Resonance Imaging
Brain

ASJC Scopus subject areas

  • General

Cite this

MRI Simulation Study Investigating Effects of Vessel Topology, Diffusion, and Susceptibility on Transverse Relaxation Rates Using a Cylinder Fork Model. / Shazeeb, Mohammed Salman; Kalpathy-Cramer, Jayashree; Issa, Bashar.

In: Scientific Reports, Vol. 7, No. 1, 15968, 01.12.2017.

Research output: Contribution to journalArticle

@article{6ae484dcacdc4597bfe33672a8f6ab3d,
title = "MRI Simulation Study Investigating Effects of Vessel Topology, Diffusion, and Susceptibility on Transverse Relaxation Rates Using a Cylinder Fork Model",
abstract = "Brain vasculature is conventionally represented as straight cylinders when simulating blood oxygenation level dependent (BOLD) contrast effects in functional magnetic resonance imaging (fMRI). In reality, the vasculature is more complicated with branching and coiling especially in tumors. Diffusion and susceptibility changes can also introduce variations in the relaxation mechanisms within tumors. This study introduces a simple cylinder fork model (CFM) and investigates the effects of vessel topology, diffusion, and susceptibility on the transverse relaxation rates R2∗and R2. Simulations using Monte Carlo methods were performed to quantify R2∗and R2 by manipulating the CFM at different orientations, bifurcation angles, and rotation angles. Other parameters of the CFM were chosen based on physiologically relevant values: vessel diameters (∼2-10 μm), diffusion rates (1 × 10-11-1 × 10-9 m2/s), and susceptibility values (3 × 10-8-4 × 10-7 cgs units). R2∗and R2 measurements showed a significant dependence on the bifurcation and rotation angles in several scenarios using different vessel diameters, orientations, diffusion rates, and susceptibility values. The angular dependence of R2∗and R2 using the CFM could potentially be exploited as a tool to differentiate between normal and tumor vessels. The CFM can also serve as the elementary building block to simulate a capillary network reflecting realistic topological features.",
author = "Shazeeb, {Mohammed Salman} and Jayashree Kalpathy-Cramer and Bashar Issa",
year = "2017",
month = "12",
day = "1",
doi = "10.1038/s41598-017-15968-4",
language = "English (US)",
volume = "7",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",
number = "1",

}

TY - JOUR

T1 - MRI Simulation Study Investigating Effects of Vessel Topology, Diffusion, and Susceptibility on Transverse Relaxation Rates Using a Cylinder Fork Model

AU - Shazeeb, Mohammed Salman

AU - Kalpathy-Cramer, Jayashree

AU - Issa, Bashar

PY - 2017/12/1

Y1 - 2017/12/1

N2 - Brain vasculature is conventionally represented as straight cylinders when simulating blood oxygenation level dependent (BOLD) contrast effects in functional magnetic resonance imaging (fMRI). In reality, the vasculature is more complicated with branching and coiling especially in tumors. Diffusion and susceptibility changes can also introduce variations in the relaxation mechanisms within tumors. This study introduces a simple cylinder fork model (CFM) and investigates the effects of vessel topology, diffusion, and susceptibility on the transverse relaxation rates R2∗and R2. Simulations using Monte Carlo methods were performed to quantify R2∗and R2 by manipulating the CFM at different orientations, bifurcation angles, and rotation angles. Other parameters of the CFM were chosen based on physiologically relevant values: vessel diameters (∼2-10 μm), diffusion rates (1 × 10-11-1 × 10-9 m2/s), and susceptibility values (3 × 10-8-4 × 10-7 cgs units). R2∗and R2 measurements showed a significant dependence on the bifurcation and rotation angles in several scenarios using different vessel diameters, orientations, diffusion rates, and susceptibility values. The angular dependence of R2∗and R2 using the CFM could potentially be exploited as a tool to differentiate between normal and tumor vessels. The CFM can also serve as the elementary building block to simulate a capillary network reflecting realistic topological features.

AB - Brain vasculature is conventionally represented as straight cylinders when simulating blood oxygenation level dependent (BOLD) contrast effects in functional magnetic resonance imaging (fMRI). In reality, the vasculature is more complicated with branching and coiling especially in tumors. Diffusion and susceptibility changes can also introduce variations in the relaxation mechanisms within tumors. This study introduces a simple cylinder fork model (CFM) and investigates the effects of vessel topology, diffusion, and susceptibility on the transverse relaxation rates R2∗and R2. Simulations using Monte Carlo methods were performed to quantify R2∗and R2 by manipulating the CFM at different orientations, bifurcation angles, and rotation angles. Other parameters of the CFM were chosen based on physiologically relevant values: vessel diameters (∼2-10 μm), diffusion rates (1 × 10-11-1 × 10-9 m2/s), and susceptibility values (3 × 10-8-4 × 10-7 cgs units). R2∗and R2 measurements showed a significant dependence on the bifurcation and rotation angles in several scenarios using different vessel diameters, orientations, diffusion rates, and susceptibility values. The angular dependence of R2∗and R2 using the CFM could potentially be exploited as a tool to differentiate between normal and tumor vessels. The CFM can also serve as the elementary building block to simulate a capillary network reflecting realistic topological features.

UR - http://www.scopus.com/inward/record.url?scp=85035114886&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85035114886&partnerID=8YFLogxK

U2 - 10.1038/s41598-017-15968-4

DO - 10.1038/s41598-017-15968-4

M3 - Article

VL - 7

JO - Scientific Reports

JF - Scientific Reports

SN - 2045-2322

IS - 1

M1 - 15968

ER -