[Determination of the arterial input function in mouse-models using clinical MRI]
Dorothea Theis1, Boris Keil, Johannes T Heverhagen
1Klinik für Strahlendiagnostik, Philipps-Universität Marburg, Marburg. dorothea.theis@gmail.com
Abstract:
Dynamic contrast enhanced Magnetic Resonance Imaging is a promising method for quantitative analysis of tumor perfusion and is increasingly used in study of cancer in small animal models. In those studies the determination of the arterial input function (AIF) of the target tissue can be the first step. Series of short-axis images of the heart were acquired during administration of a bolus of Gd-DTPA using saturation-recovery gradient echo pulse sequences. The AIF was determined from the changes of the signal intensity in the left ventricle. The native T1 relaxation times and AIF were determined for 11 mice. An average value of (1.16+/-0.09) s for the native T1 relaxation time was measured. However, the AIF showed significant inter animal variability, as previously observed by other authors. The inter-animal variability shows, that a direct measurement of the AIF is reasonable to avoid significant errors. The proposed method for determination of the AIF proved to be reliable.
Insights
Dynamic contrast-enhanced MRI helps quantify tumor perfusion in animal models. Measuring the arterial input function (AIF) directly in each animal is crucial due to significant variability, ensuring accurate cancer research.
Area of Science:
- Biomedical Imaging
- Pharmacokinetics
- Cancer Research
Context:
- Dynamic contrast-enhanced Magnetic Resonance Imaging (DCE-MRI) is vital for assessing tumor perfusion in preclinical cancer studies.
- Accurate determination of the arterial input function (AIF) is a critical first step in quantitative DCE-MRI analysis.
- Small animal models are increasingly used to study cancer, requiring precise physiological measurements.
Purpose:
- To determine the native T1 relaxation times and arterial input function (AIF) in mice using DCE-MRI.
- To evaluate the reliability of a proposed method for AIF determination in small animal models.
- To highlight the necessity of direct AIF measurement due to inter-animal variability.
Summary:
- A method was developed to determine the arterial input function (AIF) from left ventricle signal intensity changes during Gd-DTPA administration in mice.
- Native T1 relaxation times averaged (1.16+/-0.09) s.
- Significant inter-animal variability in AIF was observed, confirming the need for direct measurement to minimize errors.
Impact:
- The study validates a reliable method for determining AIF in small animal models, crucial for accurate tumor perfusion quantification.
- This work supports the advancement of quantitative DCE-MRI in preclinical cancer research.
- Improved accuracy in AIF measurement can lead to more effective drug development and treatment strategies in oncology.
