Anthropomorphic thorax phantom for cardio-respiratory motion simulation in tomographic imaging

Area of Science:

• Medical Imaging Physics
• Biomedical Engineering
• Radiological Sciences

Background:

• Patient motion during medical imaging (CT, MRI, PET, SPECT) causes image degradation like blurring and artifacts.
• Existing motion correction methods require validation under realistic physiological conditions.
• Simulating complex cardio-respiratory motion is crucial for accurate assessment of imaging techniques.

Purpose of the Study:

• To introduce a novel, MR-compatible anthropomorphic thorax phantom named Wilhelm.
• To enable realistic simulation of cardio-respiratory motion for advanced imaging studies.
• To provide a platform for validating motion correction techniques in hybrid imaging and radiotherapy.

Main Methods:

• Development of an anthropomorphic thorax phantom with inflatable lungs, a beating left ventricle, and simulated moving lesions/plaques.
• Phantom designed for MR-compatibility, allowing studies across CT, PET, SPECT, and MRI modalities.
• Incorporation of features simulating respiration-induced motion and cardiac dynamics.

Main Results:

• The Wilhelm phantom successfully simulates diverse cardio-respiratory motions within a human-like thorax.
• Demonstrated utility in assessing detectability of coronary plaque lesions in PET/CT under motion.
• Evaluated the accuracy of left ventricular blood volume measurements with simulated motion.

Conclusions:

• The Wilhelm phantom is a sophisticated tool for studying motion effects in hybrid emission tomography and radiotherapy.
• It facilitates realistic validation of motion correction strategies for various medical imaging techniques.
• Enables improved accuracy in quantitative imaging of cardiac and thoracic structures affected by motion.