Shutter-speed dynamic contrast-enhanced MRI: Is it fit for purpose?

Area of Science:

• Radiology
• Medical Imaging
• Biophysics

Background:

• Dynamic contrast-enhanced (DCE) MRI is a key imaging technique.
• Estimating water exchange (WX) is crucial for understanding tumor physiology.
• Current models for WX estimation in DCE-MRI require further validation.

Purpose of the Study:

• To evaluate the efficacy of shutter-speed DCE-MRI in quantifying water exchange (WX).
• To assess the performance of WX estimation models in simulated and clinical breast tumor data.
• To compare shutter-speed DCE-MRI with other kinetic models for tumor characterization.

Main Methods:

• Simulated DCE-MRI data using 1- and 2-compartment tracer kinetic (TK) models combined with WX models.
• Acquisition parameters included WX-sensitive (8°) and WX-insensitive (25°) flip angles.
• Clinical data from malignant and benign breast tumors were analyzed using various TK and WX models.

Main Results:

• Simulated data showed poor WX estimates with 2-pool WX (2PX) and shutter-speed models.
• Malignant tumor data fitting was poor with 1-compartment TK models, except for the shutter-speed model, which overestimated parameters.
• Benign tumor data showed excellent fits with all models, indicating 1 tracer compartment sufficiency.

Conclusions:

• The 2PX and shutter-speed models are inadequate for estimating WX from DCE-MRI data.
• A good fit with the shutter-speed model in malignant tumors does not reflect accurate WX estimation.
• Inappropriate TK model selection can lead to distorted parameter estimates in DCE-MRI analysis.