The speaker introduces an MRI physics module, comparing the learning process to assembling a puzzle. The MRI machine, made of multiple layers of magnets, generates images using nuclear magnetic resonance, primarily from hydrogen atoms within the patient's body. These hydrogen atoms, due to their magnetic properties, align with the machine's main magnetic field and precess around their own axis.
The speaker explains that a second magnetic field, known as the radio frequency pulse, is applied, causing the hydrogen atoms to move into a transverse plane, where they gain transverse magnetization. This process is dependent on the radio frequency pulse matching the protons' processional frequency.
The speaker also discusses the concept of the free induction decay (T2*) curve, which represents the rate at which transverse magnetization is lost. Different tissues have different T2* curves, which can be used to generate contrast in MRI images.
The speaker mentions that the process of gaining longitudinal magnetization (T1 recovery) and the loss of transverse magnetization are independent of each other. The time of echo (TE) and the time of repetition (TR) are key parameters that can be manipulated to generate different contrasts in MRI images.
The speaker concludes by emphasizing the importance of understanding these concepts as the basis for creating MRI images. The speaker also mentions a question bank for self-testing and identifying knowledge gaps. The speaker looks forward to the upcoming talks where each aspect will be discussed in detail.
1. The MRI physics module is divided into multiple talks, each delving into specific details of MRI physics. The goal is to provide a comprehensive understanding of how MRI physics works [Document(page_content="00:00:00.00: hello everybody and welcome to the MRI\n00:00:01.86: physics module I can't wait to share the\n00:00:04.02: upcoming talks with you now this course\n00:00:06.24: consists of multiple different talks and\n00:00:08.58: each one dives into a fair amount of\n00:00:10.68: detail regarding that specific topic and\n00:00:12.90: it's my hope that by the end of this\n00:00:14.52: module you'll have a good conceptual\n00:00:16.44: understanding as to how exactly MRI\n00:00:18.84: physics works now I think about learning\n00:00:21.54: MRI physics much like building a large\n00:00:23.46: puzzle if I was to pour all the puzzle\n00:00:25.86: pieces out on the table and pick up one\n00:00:27.60: piece it'll be very difficult for me to\n00:00:29.58: accurately place that piece where it\n00:00:31.50: goes on the table what we want to do is\n00:00:33.90: separate the puzzle into the edge pieces\n00:00:36.00: find the corners separated into various\n00:00:38.64: different color groups and then work on\n00:00:40.98: each one of those groups individually\n00:00:42.54: before combining them to give us the\n00:00:44.82: overall picture now what I want to do\n00:00:46.92: today is show you the front cover of the\n00:00:48.90: puzzle we're trying to build show you\n00:00:50.94: where we're going throughout this course\n00:00:52.44: then we can take a step back and work on\n00:00:55.20: each one of these individual sections\n00:00:56.82: before putting them together and\n00:00:58.50: hopefully having a good clear understand\n00:01:00.00: scanning of how MRI physics works now as\n00:01:03.30: you'll see here is a 3D model of the MRI\n00:01:05.76: machine itself and you can see it's made\n00:01:08.28: of multiple different layers and each\n00:01:10.08: one of these layers represents a\n00:01:12.12: different type of magnet that we're\n00:01:13.56: going to use to generate our image now\n00:01:16.20: if we look at the machine from side on\n00:01:18.18: and then open up that machine we can see\n00:01:20.70: where the patient lies within the MRI\n00:01:22.98: machine", metadata={})].
2. In MRI imaging, the signal used to generate the image comes from within the patient. The signal is localized using the Cartesian plane, which separates the image into three axes: the longitudinal axis (Z or z-axis), the transverse plane (X Y plane), and the axial plane [Document(page_content="00:00:52.02: the Cartesian