Development of cardiac phantom which mimics the heart function using a 4.7t preclinical MRI system for cardiac imaging

Abstract

Cardiac MRI was one of the first MRI applications in the 1980s, which helps in the human study of different cardiovascular diseases. MRI is a noninvasive imaging technique that can be used for diagnosis and has advantages over other imaging techniques since it does not rely on radiation like X-rays, PET, and SPECT. Modern clinical methods do not require much scanning time, it revels good contrast between tissues and can compensate for patient movement during the scan. The scanner used is a 300mm internal diameter superconducting magnet (Magnex Uk) 4.7T preclinical MRI system, in the Biomedical Physics building at the University of Aberdeen. The cardiac phantom is made of a balloon filled with water, connected via a nylon T-piece to two 5 m lengths of rigid pvc tubing of 3 mm internal diameter to a 12 V water pump and solenoid valve located outside the 4.7 T MRI system’s 5 Gauss stray field contour. The balloon part of the phantom was fixed on the 4.7 T MRI system’s animal bed, directly over a 30mm diameter surface coil normally used to image the rat heart. The flow system was primed with water to mimic blood and the bed was loaded into the MRI magnet for imaging. The cardiac phantom has successfully been developed using a small balloon to represent a heart chamber and imaged in a 4.7T preclinical MRI scanner. Images acquired with gradient echo pulse sequence with shorter TE of 5 ms and using surface coil displayed improved image contrast and have useful signal-to-noise ratio as compared to images acquired with birdcage coil which show ghosting artifact.