An absolute contraindication of MRI is:

An absolute contraindication of MRI is:
a) Pacemaker
b) Prosthetic cardiac valves
c) Insulin pump
d) Choclear implants
Correct Answer - A
Pacemaker [Ref: Harrison 17/e p2494; Grainger Diagnostic
Radiology 4/e p122;
various websites-http://www.mr-tip.com/servl.php?ope=dbl
&dbs=Prosthetic%20Heart%20Valves
http://www. imrser.org/PDF/Shellock.HeartValves.JMRLpdf; http
://www. mrtip. com/se ry 1.php ?type = dh 1 &dbs= Prosthetic
%20Heart %20Valves
;and journal- _RadioGraphic s 2004 ;24 : 1257- 1267
MR is considered among the safest imaging modalities for patients,
even at very high field strengths, more than 3-4 tesla.
But Ferromagnetic objects under magnetic field can be vulnerable to
4 adverse effects:
Movement (causing structural injury),
Current conduction (potentially causing electrical shock),
Heating (possibly causing burn injury), and
Artifact generation
Serious injuries can be caused by attraction of ferromagnetic objects
into the magnet, which would act as missiles if brought too close to
the magnet.
Ferromagnetic implants, such as aneurysm clips, may torque (turn
or twist) due to the magnetic field, causing damage to vessels and
even death