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Updated: May 30, 2026
11:27
Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging
Published on: December 4, 2016
First order correction for T2*-relaxation in determining contrast agent concentration from spoiled gradient echo
Dieter De Naeyer1, Isabelle Debergh, Yves De Deene
1Institute Biomedical Technology (IBiTech), Department of Civil Engineering, Ghent University, Belgium. dieter.denaeyer@ugent.be
Journal of Magnetic Resonance Imaging : JMRI
|July 20, 2011
Summary
A new method accurately converts MRI signal intensity to contrast agent concentration by accounting for T(2)*-relaxation. This dynamic contrast-enhanced MRI technique significantly reduces underestimation errors in both tissue and arterial measurements.
Area of Science:
- Medical Imaging
- Biophysics
- Radiology
Background:
- Dynamic contrast-enhanced (DCE) MRI is crucial for assessing tissue perfusion and vascularity.
- Accurate conversion of MRI signal intensity to contrast agent (CA) concentration is vital for quantitative analysis.
- Previous methods often neglect T(2)*-relaxation, potentially leading to inaccurate CA concentration measurements.
Purpose of the Study:
- To evaluate the accuracy of a simplified method that neglects T(2)*-relaxation for CA concentration conversion in DCE-MRI.
- To introduce and validate a novel, closed-form conversion expression incorporating a first-order approximation of T(2)*-relaxation.
Main Methods:
- Theoretical comparison of the T(2)*-neglecting method and the proposed first-order method using simulations across four pulse sequences.
- In vivo validation of both methods against a numerical conversion method for arterial input function measurement in mice.
Main Results:
- Simulations revealed underestimation of tissue CA concentrations by up to 6% and arterial concentrations by up to 43% with the T(2)*-neglecting method.
- The proposed first-order method demonstrated numerically indistinguishable results from simulation inputs in tumor tissue.
- In vivo studies showed the T(2)*-neglecting method underestimated peak Gd-DOTA concentration by up to 14%, while the first-order method showed an underestimation of only 0.9%.
Conclusions:
- The proposed first-order conversion method significantly reduces the underestimation of contrast agent concentration across a wide physiological range.
- This new method is accurate, easy to implement in clinical settings, and improves quantitative analysis in DCE-MRI.
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