A compact solution for estimation of physiological parameters from ultrafast prostate dynamic contrast enhanced MRI

Area of Science:

• Radiology
• Medical Imaging
• Pharmacokinetics

Background:

• The Tofts pharmacokinetic model, commonly used for dynamic contrast-enhanced MRI (DCE-MRI) analysis, involves complex calculations and may be unsuitable for prostate imaging.
• Model limitations can lead to error propagation, reducing the accuracy of pharmacokinetic measurements like K ^trans and v _e.

Purpose of the Study:

• To present a simplified, compact solution for estimating physiological parameters K ^trans and v _e from ultrafast DCE-MRI acquisitions.
• To avoid fitting DCE-MRI data to the standard Tofts pharmacokinetic model, thereby reducing computational complexity and potential errors.

Main Methods:

• Utilized ultrafast DCE-MRI data from 18 prostate cancer patients.
• Applied a compact solution simplifying the Tofts model to the Patlak model at early times and using the derivative form for late-state signal analysis.
• Calculated contrast media concentration using gradient echo signal equations and a reference tissue model.

Main Results:

• Strong correlations (r = 0.88-0.91) were observed between K ^trans values from the Tofts model and the compact solution for prostate cancer and normal tissue.
• Moderate correlations (r = 0.65-0.73) were found for v _e.
• Bland-Altman analysis indicated good agreement between the two methods, with low absolute bias for both K ^trans and v _e.

Conclusions:

• The compact solution offers a potentially more accurate and efficient method for pharmacokinetic analysis in DCE-MRI, especially for prostate cancer.
• This approach may reduce systematic errors and improve the clinical workflow.
• High temporal resolution DCE-MRI is crucial for the successful implementation of this compact solution.