Radiation Safety and Patient Care
Dose philosophy
ALARA governs every case: use the lowest dose that answers the clinical question. Time, distance, and shielding are the levers; doubling distance from the scatter source cuts exposure to about one quarter by the inverse square law. Lead aprons of 0.5 mm Pb attenuate most diagnostic scatter, and thyroid shields and leaded glasses address thyroid and lens dose. Personal dosimeters are worn at collar level outside the apron, with a second badge under the apron in high-workload labs.
Practical dose reduction
Pulsed fluoroscopy, low frame rates, last-image hold, tight collimation, and avoiding magnification all reduce dose. Keep the image receptor close to the patient and the tube as far as practical. Record fluoroscopy time, dose-area product, and air kerma; high air kerma values trigger review. Occupational effective dose limits are far above public limits (public is about 1 mSv per year), so never quote public limits for workers.
Patient care
Before the procedure verify allergies (especially iodinated contrast), renal function, hydration, anticoagulation status, and informed consent. After the procedure monitor the access site, distal pulses, blood pressure, and signs of bleeding or hematoma; hydration aids contrast clearance. Treat vasovagal reactions with leg elevation and fluids.
Traps
- Placing the collar badge under the apron.
- Confusing public and occupational dose limits.
- Assuming contrast nephropathy is unavoidable; hydration and minimizing volume matter.
Rule of thumb
If fluoroscopy time is climbing without progress, step back, collimate, lower the frame rate, and re-plan instead of screening to think.