A Low-Cost Portable 50 mT MRI Scanner for Dental Imaging

Magnetic resonance imaging (MRI) has proven excellent performance in dental imaging, especially for temporomandibular joint (TMJ), teeth, and periodontal apparatus; however, the high price and strict installation environment of the conventional high-field MRI has prevented its widespread use in dental clinics or developing regions. The introduction of low-cost and portable MRI scanners will help increase the easy accessibility of MRI examinations and reduce the patients’ waiting time. This work introduces a low-cost portable 50 mT MRI scanner for dental imaging. First, the overall structure, including permanent magnets, gradient coils, and radio frequency (RF) coils, is introduced. The cooling system is removed because the static field is maintained by the permanent magnets. The system stands 90 cm wide and 110 cm high and weighs 600 kg, which makes it possible to install in an average-sized room. Then, the design processes of specialized RF receiving coils for TMJ teeth are illustrated. In order to improve patient comfort, an intraoral wireless coil for boosting the signal-to-noise ratio (SNR) inside the oral cavity is proposed; furthermore, the $T_{1}$ -weighted images of TMJ and teeth are given to show the dental imaging performance of the proposed device.