The AAPM/RSNA physics tutorial for residents. Basic physics of MR imaging: an introduction

Area of Science:

• Physics
• Medical Imaging

Background:

• Magnetic Resonance (MR) imaging is a cornerstone of modern medical diagnostics.
• Understanding the fundamental physical principles is crucial for effective application and interpretation of MR images.

Purpose of the Study:

• To provide a foundational understanding of the physical principles underlying MR imaging.
• To explain key concepts including nuclear magnetism, magnetization, precession, excitation, and relaxation.

Main Methods:

• Explanation of nuclear spin properties and their behavior in magnetic fields.
• Description of tissue magnetization and relaxation processes (T1, T2, T2*).
• Overview of basic planar MR pulse sequence elements: section selection, phase encoding, and frequency encoding.

Main Results:

• Clear presentation of fundamental MR physics concepts.
• Explanation of how hydrogen spin density and relaxation times influence image contrast.
• Introduction to the basic components of an MR pulse sequence.

Conclusions:

• A solid grasp of these basic physical principles is essential for comprehending MR imaging.
• This foundational knowledge aids in the effective use and interpretation of MR data.