Magnetic Resonance Image Safety

Outline

Mind Map

Learning Objectives

Teaching Visuals

Online Module
(Requires Enrollment)

Text Reference

 

Outline and Learning Guide


INTRODUCTION AND OVERVIEW

MAGNETIC FIELDS

Physical Characteristics

Biological Effects

Internal Objects

External Objects

Magneto-electrical Effects

Activation of or Damage to Implanted Devices

GRADIENTS

RF ENERGY

Specific Absorption Rate (SAR)

Magnetic Field Strength

Pulse Flip Angles

Pulses Per Cycle

TR

Determining the SAR for a Patient

Surface Burns

ACOUSTIC NOISE

MIND MAP and SUMMARY

 

 

 

Learning Objectives

 
  • Identify and briefly describe the various environmental conditions that a patient is in during an MR imaging procedure that can produce injury.
     
  • Describe and compare the safety concerns associated with both the external and internal (to the magnet) areas of the magnetic field.
     
  • Briefly describe and compare the characteristics of stochastic and deterministic biological effects and the expectation that they will be produced by magnetic fields.
  • Describe the purpose and the general elements that makeup a Magnetic Field Safety Program.
     
  • Explain why ferromagnetic objects that might be in a patient's body are potential sources of injury.
  • List and briefly describe the types of medically implanted metal objects that might be found in a patient's body and can be a potential hazard when the patient is placed in a magnetic field.
  • List and briefly describe the types of accidentally imbedded metal objects that might be found in a patient's body and can be a potential hazard when the patient is placed in a magnetic field.
  • Briefly describe what effects might be observed because of the motion of the heart in the magnetic field.
  • Explain why a general policy is to exclude patients with pacemakers from magnetic fields.
  • Describe in detail, the process of screening patients to determine if they might have internal metal objects.
  • Describe the procedure for determining if a specific medical device, such as a surgical clip, is a potential hazard when the patient is placed in a magnetic field.
  • Explain why it is not safe to bring many common metal objects into the magnetic field area.
  • Identify common metal objects (as many as possible) that can become hazards if brought into the magnetic field area.
  • Describe completely the procedures to be followed to prevent hazardous metal objects to be brought into the magnetic field area.
  • Explain the physical effects than can be produced in tissue by the gradients.
  • Identify and briefly describe the design and operational factor associated with gradients that must be considered with respect to patient safety.
  • Explain the physical effects
    than can be produced in tissue by the RF (Radio Frequency) pulses.
  • Describe the physical quantity, SAR (Specific Absorption Rate), and explain how it is used in MRI.
  • Identify and briefly explain the factors that determine the SAR value
    for a specific imaging procedure.
  • Identify the conditions that can produce skin burns during an MRI acquisition and describe the steps to take to prevent them.

 

 

Text Reference

Chapter 15

Magnetic Resonance Imaging: Principles, Methods, and Techniques
Medical Physics Publishing,  http://www.medicalphysics.org

 

 

Mind Map