Elsevier

Physica Medica

Volume 34, February 2017, Pages 38-47
Physica Medica

Original paper
Assessment of micronecrotic tumor tissue using dynamic contrast-enhanced magnetic resonance imaging

https://doi.org/10.1016/j.ejmp.2017.01.010Get rights and content
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Highlights

  • Contrast agent diffusion in inhomogeneous tissue using a macroscopic model is described.

  • Methodology of diffusion simulation in an inhomogeneous tissue is presented.

  • The impact of necrotic tumor tissue on contrast enhancement is investigated.

  • Why compartment models may provide an interstitial volume >100.

  • The possibility to assess necrotic tumor tissue using DCE-MRI is demonstrated.

Abstract

Compartmental models for evaluation of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) datasets assume a homogeneous interstitital volume distribution and homogeneous contrast agent (CA) distribution within each compartment, neglecting effects of CA diffusion within the compartments. When necrotic or micronecrotic tumor tissue is present, these assumptions may no longer be valid. Therefore, the present study investigates the validity of three compartmental models in assessing tumors with necrotic components.

The general diffusion equation for inhomogeneous tissue was used to simulate the extravasation of a low-molecular-weight contrast agent from a feeding vessel into the interstitial space. The simulated concentration-time curves were evaluated using the extended Tofts model, a parallel 3-compartment model, and a sequential 3-compartment model.

The extended Tofts model overestimated the interstitial volume fraction by a median of 6.9% resp. 10.0% and the parallel 3-compartment model by 8.6% resp. 15.5%, while the sequential 3-compartment model overestimated it by 0.2% resp. underestimated it by 18.8% when simulating a mean vessel distance of 100 μm resp. 150 μm. Overall, the sequential 3-compartment model provided more reliable results both for the total fractional interstitial volume and for the interstitial subcompartments.

Keywords

DCE-MRI
Diffusion
Contrast agent
Interstitium
Tumor
Necrotic tissue

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