Hazards in MRI Scanning

While MRI scanning can yield essential information to support patient care, like many clinical procedures, it does carry some clinical risk.

Clinical risk

Hazards in MRI scanning
1. History of renal disease
2. History of allergy
3. History of injury involving projectiles
4. History of surgery with retained metallic items, e.g. surgical clips, pacemaker, stents

Clearly, unlike x-ray based modalities, there is no ionising radiation risk, but the intense magnetic field produced in the scanning environment can be a source of danger.

In particular, the intensity of the field can lead to projectile damage, both external and internal. Objects with magnetic properties can be attracted at high speed to the device and impinge on anything and anyone in their path.

Objects

Scissors test: note the orientation of the scissors to the magnetic field.

All patients undergoing imaging must be screened for retained metallic objects internally [9]. These can include shrapnel from wounds, pacemakers, surgical clips, etc. Any of these are at risk of violent movement or malfunction with potentially disastrous consequences.

See ‘Screening patients for MR procedures and individuals for the MR environment’ in Further Reading and Activities for a screening form used by some radiologists in the USA.

Learning bite

High intensity magnetic fields are hazardous.