MRI MRI Patient Care and Positioning 2 — Questions and Answers
Question 1: Which vital sign parameter is most critical to monitor during MRI in a sedated pediatric patient?
- Blood pressure only
- Oxygen saturation via MR-compatible pulse oximetry (Correct answer)
- Temperature with a mercury thermometer
- Heart rate via standard ECG only
Correct answer: Oxygen saturation via MR-compatible pulse oximetry
Continuous oxygen saturation monitoring via MR-compatible pulse oximetry is essential in sedated pediatric patients to detect respiratory compromise caused by sedation.
Question 2: For MRI of the breast, the patient should be positioned in which orientation?
- Supine with arms at sides
- Prone with breasts hanging freely in a dedicated bilateral breast coil (Correct answer)
- Lateral decubitus on the affected side
- Upright sitting position
Correct answer: Prone with breasts hanging freely in a dedicated bilateral breast coil
Prone positioning with the breasts hanging freely in dedicated bilateral surface coils minimizes motion and maximizes coil coupling for optimal breast MRI.
Question 3: Gadolinium contrast extravasation at the IV injection site is classified as which type of adverse event?
- Allergic-like reaction
- Non-allergic physiologic reaction
- Local injection site reaction (extravasation) (Correct answer)
- Vascular reaction
Correct answer: Local injection site reaction (extravasation)
Extravasation occurs when contrast leaks from the vein into surrounding tissue; it is a local injection site reaction, not a systemic allergic event.
Question 4: When performing MRI on a patient with an insulin pump, which step is essential before beginning the exam?
- Increase the insulin dose before scanning
- Remove the pump (if removable) or verify the pump is MR-conditional with the manufacturer before scanning (Correct answer)
- Tape the pump to the patient's leg during the scan
- Leave the pump in place since insulin is not ferromagnetic
Correct answer: Remove the pump (if removable) or verify the pump is MR-conditional with the manufacturer before scanning
Insulin pumps may malfunction, heat, or be damaged in the MRI environment; removal or manufacturer verification of MR-conditional status is mandatory.
Question 5: The landmark for centering an MRI brain exam using a head coil is located at:
- Top of the skull
- Nasion or bridge of the nose (Correct answer)
- External auditory meatus
- Occiput
Correct answer: Nasion or bridge of the nose
The nasion (bridge of the nose) is the standard external landmark used to center the isocenter of the MRI system for brain imaging.
Question 6: Which patient condition requires consultation with the ordering physician regarding MRI safety due to potential risks during the first trimester?
- Known diabetes mellitus
- Known pregnancy, especially first trimester (Correct answer)
- Mild hypertension controlled with oral medication
- Prior abdominal surgery more than 1 year ago
Correct answer: Known pregnancy, especially first trimester
MRI in the first trimester is performed with caution; although no confirmed harm is established, ACR guidelines recommend physician consultation and clinical justification for first-trimester MRI.
MRI MRI Patient Care and Positioning 2
Which vital sign parameter is most critical to monitor during MRI in a sedated pediatric patient?