Catheter-based Arterial Input Function Determination for Myocardial Perfusion Measurements
Simon Stephan1, Simon Reiss1, Thomas Lottner1
1Department of Radiology - Medical Physics, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Insights
This study presents a novel catheter-based method for measuring the arterial input function (AIF) during cardiovascular interventions. This technique enables accurate myocardial perfusion quantification, potentially speeding up assessments during procedures.
Area of Science:
- Cardiovascular Imaging
- Medical Physics
- Interventional Radiology
Background:
- Accurate myocardial perfusion quantification relies on precise arterial input function (AIF) determination.
- Current AIF measurement methods can be time-consuming and may not be optimal for real-time interventional guidance.
Purpose of the Study:
- To evaluate an MR-guided method for determining the AIF using an active tracking catheter during targeted contrast agent (CA) injection.
- To assess the feasibility and accuracy of catheter-based AIF measurements for myocardial perfusion quantification.
Main Methods:
- A phantom experiment using a dialysis filter was conducted to measure AIF with an active catheter and dynamic MR imaging.
- Correction methods were developed to address dilution and coil sensitivity effects for catheter-based AIF.
- Quantitative perfusion maps were calculated via deconvolution and normalized using flow measurements.
Main Results:
- Catheter-based and imaging-based AIF measurements showed agreement in signal-time curves, with a scaling factor difference of approximately 9.
- After normalization to surrounding flow, both perfusion quantification techniques demonstrated excellent agreement.
- Catheter-based AIF measurement is feasible but requires normalization via flow measurement.
Conclusions:
- Catheter-based AIF measurement is a viable approach for myocardial perfusion quantification during cardiovascular interventions.
- This technique, after normalization, provides results comparable to imaging-based methods.
- The method holds potential for enabling faster perfusion assessments in interventional settings.
Abstract:
The quantification of myocardial perfusion with contrast agent (CA) tracers requires the precise knowledge of the arterial input function (AIF). In this study a method for MR-guided vascular interventions is evaluated that determines the AIF via an active tracking catheter during targeted CA injection. A phantom experiment with a dialysis filter was conducted to measure the AIF using an active catheter and a dynamic image series as reference. To compensate for dilution and coil sensitivity effects, correction methods were developed for the catheter-based AIF determination. From the dynamic MR measurements in the perfusion phantom quantitative perfusion maps were calculated by a deconvolution of the measured CA concentration with the AIF, and additional flow measurements were used to normalize the perfusion map. The signal-time-curves of the measured AIF using the catheter-based and imaging-based methods agree while the absolute values differ by a scaling factor of about 9. After normalization to the surrounding flow, both perfusion techniques are in excellent agreement. Catheter-based AIF measurements are feasible but require an additional normalization which can be determined from a flow measurement. The technique might enable faster perfusion measurements during cardiovascular interventions.
