MRI 220 - MR Physics I

2. In this section we will explore the conditions by which resonance occurs, the effect of hydrogen after the initial excitation pulse is removed. Introduction to T1 Recovery and T2 decay.

3. This section will further explain T1 and T2 weighted tissue characteristics. The differences in relaxation times for fat and water based on timing parameters. Introduction to different pulse sequences.

4. Once the MRI signal is formed it must be encoded and stored to represent out image. In this module, we will explore the localization of the Gradients and their use to encode the signal.

5. In this module, we will explore the operator control variables that allow technologists to modify given protocols to achieve the best possible SNR and Resolution. Define the various types of resolution.

6. Use of Pulse Sequences to achieve image contrast. Each Pulse Sequence will be identified.
Course Outline:
I. Identify and discuss the basic principles of MRI.

A. Differentiate between nuclear magnetic resonance and magnetic resonance imaging.

B. Discuss the role of electromagnetism in MRI.

C. Identify the three requirements for MRI.

D. Discuss the basic structure of the atom.

E. Identify the three types of motion present with an atom.

F. State the Larmor Equation and relate its importance to MRI

G. Describe the appearance of net magnetization on a vector diagram.

H. Discuss and define resonance.

I. State the conditions necessary for resonance to occur.

J. Characterize MR active nuclei.

K. Identify Quantum theory as it relates to MRI.

L. Differentiate between the magnetic moments of hydrogen nuclei as they align with Bo.

M. Discuss procession and identify its relationship to magnetic moments.

N. Discuss flip angle as it relates to the nuclear magnetic vector.

O. Differentiate between In and Out of Phase conditions.

P. State Faraday’s Law of Electromagnetic Induction.

Q. Discuss the importance of Faraday’s Law of Electromagnetic Induction to MRI.

II. Identify and discuss the intrinsic parameters that affect image quality.

A. Discuss the relaxation of hydrogen as the nuclear magnetic vector returns to Bo.

B. Identify the two basic measurements of relaxation in magnetic resonance.

C. List the intrinsic contrast parameters.

D. Differentiate between T1 recovery and T2 decay as seen on a graph.

E. Differentiate between fat and water.

F. Discuss and differentiate between T1 recovery in fat and T1 recovery in water.

G. Discuss and differentiate between T2 decay in fat and T2 decay in water.

H. Differentiate between T1 contrast and T2 contrast of both fat and water.

I. Discuss proton density contrast.

J. Discuss the impact intrinsic contrast parameters have on image weighting.

III. Identify and discuss the extrinsic parameters that affect image quality.

A. Discuss pulse timing parameters.

B. Discuss the impact extrinsic contrast parameters have on image weighting.

C. Discuss and identify the importance of repetition time (TR).

D. Discuss and identify the importance of echo time (TE).

E. Discuss Time from Inversion (TI) and identify its use for weighting in an Inversion Recovery pulse sequence.

F. Identify the pulse sequences and operator control variables necessary to achieve image contrast.

G. Differentiate between the following pulse sequences: spin echo, fast spin echo, inversion recovery, gradient echo, and echo planar.

H. Describe the differences in TR for each type of pulse sequence.

I. Discuss and identify the weighting for each type of pulse sequence.

J. Identify the phase, frequency, and slice select position for each type of pulse sequence.

IV. Explore the localization of the gradients and their use in signal encoding.

A. Discuss Fourier Transform as it relates to signal encoding.

B. Identify the need for gradients.

C. Differentiate between the X, Y, and Z gradients.

D. Discuss k-space.

E. Discuss the areas in k-space to store the signal amplitude.

F. Discuss and differentiate between frequency encoding, phase encoding, and slice select gradients.

G. Identify how the gradient causes precessional frequencies to vary.

H. Identify the steps necessary to calculate the magnetic field at any point along the gradient.

I. identify how the phase encoding gradient, frequency encoding gradient, and slice select gradient correspond to the physical gradient.

V. Describe the operator control variables and discuss their impact on signal-to-noise and resolution.

A. Identify the parameters in a spin echo (SE) sequence (TR, TE, and Bandwidth).

B. Discuss the signal-to-noise ratio (SNR).

C. Discuss spatial resolution.

D. Differentiate between the parameters that affect SNR and detail.

E. Discuss the causes of artifact and identify ways to correct it.

F. Identify the types of resolution that are important to the MR image.