Performing MRI scans in human subjects wearing metallic orthodontic braces

Title: Performing MRI scans in human subjects wearing metallic orthodontic braces

Abstract:

MR images are very sensitive to susceptibility artifacts in the presence of metallic objects such as dental braces. This impedes the application of MRI for studies involving participants wearing metallic dental braces. It also presents a significant barrier for presurgical MRI in epilepsy and tumor patients with metallic head implants, hemorrhages, and other lesions with strong susceptibility effects. In this talk, we introduce two alternative MRI approaches in healthy human subjects wearing metallic orthodontic braces to demonstrate their ability to minimize susceptibility artifacts in the presence of metallic objects. Removable dental braces with bonding trays were used so that MR images could be acquired with and without the braces in the same subjects. Results were compared in regions with strong or minimal susceptibility effects between the current standard MRI sequences and the proposed alternatives using t-tests. The new methods showed preserved signal-to-noise ratio (SNR) in brain regions with strong or minimal susceptibility effects from the metallic braces, whereas the conventional MRI methods showed significantly impaired sensitivity in regions with strong susceptibility effects. Geometric distortion was substantially reduced throughout the brain with the proposed methods.

Biography:

Dr. Hua’s research has centered on the development of novel MRI technologies for in vivo functional and physiological imaging in the brain, and the application of such methods for studies in healthy and diseased brains. These include the development of human and animal MRI methods to measure functional brain activities, cerebral perfusion and oxygen metabolism at high (3 Tesla) and ultra-high (7 Tesla and above) magnetic fields. He is particularly interested in novel MRI approaches to image small blood and lymphatic vessels in the brain. Collaborating with clinical investigators, these techniques have been applied 1) to detect functional, vascular and metabolic abnormalities in the brain in neurodegenerative diseases such as Huntingdon’s disease (HD), Parkinson’s disease (PD), Alzheimer’s disease (AD) and mental disorders such as schizophrenia; and 2) to map brain functions and cerebrovascular reactivity for presurgical planning in patients with vascular malformations, brain tumors and epilepsy.