In vitro pharmacokinetic phantom for two-compartment modeling in DCE-MRI

Area of Science:

• Biomedical Engineering
• Medical Imaging Physics

Background:

• Dynamic contrast-enhanced MRI (DCE-MRI) is crucial for assessing tissue characteristics but faces challenges in standardization due to varied protocols and models.
• Inconsistent DCE-MRI results hinder its widespread clinical adoption and reliable interpretation.

Purpose of the Study:

• To develop and validate a novel flow phantom for standardizing DCE-MRI acquisition protocols and evaluating pharmacokinetic models.
• To enable objective comparison and optimization of DCE-MRI methods in a controlled in vitro setting.

Main Methods:

• A two-compartmental flow phantom was designed using a hemodialysis filter to simulate blood plasma and extravascular extracellular space (EES).
• Gadolinium-based contrast agent boluses were injected, and time-intensity curves (TICs) were acquired via T1-weighted DCE-MRI.
• System identification and model-based deconvolution were used to estimate trans-membrane extravasation rates under varying flow conditions.

Main Results:

• The flow phantom successfully mimicked a two-compartmental vascular bed, allowing for manipulation of extravasation rates.
• Estimated extravasation rates were significantly influenced by flow rates in the EES compartment, aligning with simulations.
• The phantom demonstrated its utility in testing and optimizing DCE-MRI sequences for consistent quantification.

Conclusions:

• The developed flow phantom provides a robust platform for validating DCE-MRI acquisition protocols and pharmacokinetic models.
• This standardized approach is expected to improve the reliability and clinical applicability of DCE-MRI for tissue assessment.
• Further research can utilize this phantom to refine DCE-MRI techniques for more accurate hemodynamic and viability analysis.