Modeling DCE-MRI at low temporal resolution: a case study on rheumatoid arthritis

Area of Science:

• Radiology
• Medical Imaging
• Pharmacokinetics

Background:

• Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is crucial for assessing rheumatoid arthritis (RA) disease activity.
• Accurate tracer-kinetic modeling is essential for interpreting DCE-MRI data, especially at low temporal resolutions.

Purpose of the Study:

• To determine the optimal tracer-kinetic modeling strategy for DCE-MRI data acquired with low temporal resolution.
• To compare the modified Tofts (MT) model and the two-compartment exchange (2CXM) model for analyzing hand synovium in RA patients.

Main Methods:

• DCE-MRI was performed on 13 RA patients before and after anti-TNFα therapy.
• Concentration-time curves from enhancing synovium were fitted using the 3-parameter MT model and the 4-parameter 2CXM model.
• Simulated data with similar characteristics were analyzed to aid interpretation.

Main Results:

• Both MT and 2CXM models showed similar therapy effects.
• MT model yielded significantly lower plasma volume compared to 2CXM.
• 2CXM demonstrated lower precision with larger standard deviations, and its additional parameter lacked statistical significance.

Conclusions:

• The standard modified Tofts (MT) model is the optimal choice for DCE-MRI analysis at low temporal resolution.
• While advanced models like 2CXM offer potential accuracy improvements, their reduced precision limits their clinical utility in this setting.