Patient Care
Screening and preparation
Every MRI encounter begins with a documented screening interview: implants and devices, foreign bodies such as shrapnel or intraocular metal, prior surgery, pregnancy status, allergies, renal function, weight, and the patient's ability to lie still and use the call device. Remove medication patches (some have metallic backing), transdermal systems, and loose metal; hospital gowns avoid zippers and snaps. Verify any implant against its labeling rather than assuming metal equals exclusion - titanium and nitinol hardware is common and often acceptable.
Contrast and renal assessment
Extracellular gadolinium agents are dosed at 0.1 mmol/kg. Assess eGFR when renal disease is suspected. For group II agents the usual caution threshold is eGFR below 30 mL/min/1.73 m², where risk and benefit are weighed and the lowest diagnostic dose is used; group I linear agents are avoided in this population because of nephrogenic systemic fibrosis risk. Breastfeeding usually may continue after gadolinium.
Comfort, communication, monitoring
Describe the noise, the intercom, the squeeze bulb, and the expected duration. Provide hearing protection for every patient. Place coils close to the anatomy, pad bony prominences, and avoid skin-to-skin contact or coiled cables that can form conductive loops. Use MRI-compatible monitoring for sedated or unstable patients, and keep emergency equipment accessible but outside the magnet room.
Traps and a worked example
Questions blur "metal" with "absolute contraindication," and they test whether you know that pregnancy is not an absolute bar to a non-contrast exam. Dose calculation: an 82 kg patient at 0.1 mmol/kg needs 8.2 mmol; with a 0.5 mmol/mL agent that is 16.4 mL.