The first half of this lecture will explain the principles of MRI.
First, I will explain the behavior of protons in MRI, focusing on the Larmor precession and frequency, NMR phenomena, and the two relaxation processes. This section requires an understanding of energy transfer and phase convergence and divergence.

Next, I will define the T1 and T2 relaxation times and present the T1 and T2 relaxation times of normal oral tissues. Next, I will introduce the five steps of MRI imaging and explain signal acquisition methods, including SE, GRE, and FSE sequences. To explain the FSE sequence, I will also briefly explain k-space. Here, I will explain how contrast is created by combining TR and TE. Lamor frequency is useful for deciding a tomographic plane. Next, the characteristics of MRI are compared with CT. This comparison will help guide strategies for selecting imaging modalities in general clinical practice.

In the second half of this lecture, I will discuss the application of MRI to the oral region. I will summarize key points and introduce relevant case studies. I will present cases of cysts, benign tumors, malignant tumors, inflammation, and temporomandibular joint disorders.

In the oral region, magnetic susceptibility artifacts from prosthetics and orthodontic appliances are often problematic. This presentation will discuss the latest findings regarding the impact of these artifacts on diagnostic imaging. It will also discuss the forces and torques exerted on prosthetic and orthodontic appliances, both inside and outside the MRI scanner.

Finally, I will introduce the latest MRI techniques for imaging teeth and bones, as well as dynamic swallowing and temporomandibular joint movement.