What are possible patient problems encountered in the MRI scanner?
The MRI environment creates an unavoidable distance between the patient and the anesthesiologist. The patient’s inaccessibility following placement in the MRI scanner can be problematical when immediate access is required. Patient visibility is limited once the patient is placed within the gantry of the scanner. Some MRI systems are equipped with a closed-circuit camera which allows for continuous visualization of the patient.
Noise is produced by the MRI scanner as a result of the vibration of wire loops producing gradient current in the presence of RF pulses. This can at times be loud and may average approximately 95 decibels. Auditory protection, such as earplugs, should be provided to all patients under-going a scan.
The risk of burns during MRI is another possible patient problem. The monitoring systems that may be associated with burns in the MRI scanner have been discussed above.
Gadopentetate dimeglumine (gadolinium) is a com-monly used MRI contrast agent. It is a low-osmolar ionic medium, with a slower clearance in neonates and infants compared with adults. Reported adverse effects include thrombophlebitis, hypotension, headache, nausea, and vomiting.
Anxiety and claustrophobia are possible problems encountered by the awake patient.