Effect of T2* correction on contrast kinetic model analysis using a reference tissue arterial input function at 7 T.

Area of Science:

• Magnetic Resonance Imaging
• Pharmacokinetics
• Biomedical Engineering

Background:

• Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) is vital for assessing tumor characteristics.
• Accurate estimation of kinetic parameters, such as K(trans) and ve, is essential for DCE-MRI analysis.
• T2* effects can potentially influence the accuracy of these parameter estimations.

Purpose of the Study:

• To evaluate the impact of T2* correction on kinetic parameter estimation in T1-weighted DCE-MRI.
• To determine if T2* correction is necessary when using a reference-tissue arterial input function (AIF).

Main Methods:

• DCE-MRI data were acquired from mouse mammary tumors using a 7T scanner.
• The extended Tofts model was employed to calculate pharmacokinetic parameters.
• T2* correction was applied to both the lesion and the AIF, with corrected parameters serving as the reference standard.

Main Results:

• A significant difference in the transfer constant (K(trans)) was observed between T2*-corrected and uncorrected methods across the study population (p < 0.05).
• No significant differences in K(trans) or interstitial volume fraction (ve) were found for most individual tumors.
• However, K(trans) was significantly underestimated without T2* correction in tumors with a median K(trans) > 0.4 min(-1).

Conclusions:

• The T2* effect can be significant in kinetic model analysis of tumors with high K(trans).
• This effect may persist even when the arterial input function is derived from reference tissue with low contrast agent concentration.
• T2* correction should be considered for accurate DCE-MRI kinetic analysis in specific tumor types.