Question 1
A radiopharmacy receives a Tc-99m vial containing 100 mCi at 6:00 AM. Assuming a physical half-life of 6 hours, how much activity remains in the vial at 6:00 PM the same day?
Show answer & explanation
Correct answer: A - 25 mCi
10 free, exam-style Nuclear Medicine Technologist Certification (NMTCB) practice questions with answers and explanations. No signup required. Work through them below, then take the full free NMTCB practice test to study every exam domain.
A radiopharmacy receives a Tc-99m vial containing 100 mCi at 6:00 AM. Assuming a physical half-life of 6 hours, how much activity remains in the vial at 6:00 PM the same day?
Correct answer: A - 25 mCi
What is the annual occupational whole-body dose limit (total effective dose equivalent) for a radiation worker under NRC regulations (10 CFR 20.1201)?
Correct answer: D - 5 rem (50 mSv) per year
A technologist measures an exposure rate of 80 mR/hr at a distance of 1 meter from a source. Using the inverse square law, what is the approximate exposure rate at 2 meters?
Correct answer: B - 20 mR/hr
Before administration, each Tc-99m generator eluate must be tested for molybdenum breakthrough. According to USP/NRC standards, the maximum permissible amount of Mo-99 at the time of administration is:
Correct answer: C - 0.15 microcurie of Mo-99 per millicurie of Tc-99m
Tc-99m MAG3 is widely used for renal imaging. The kidneys clear this radiopharmaceutical primarily by which mechanism?
Correct answer: A - Tubular secretion
Which of the following dose calibrator quality control tests is required to be performed each day before patient use?
Correct answer: D - Constancy
A technologist is preparing to image a patient who received I-131, which has a principal photon energy of 364 keV. Which collimator is MOST appropriate?
Correct answer: B - High-energy
On a Tc-99m mebrofenin hepatobiliary study, the liver and small bowel are visualized normally, but the gallbladder is not seen at 60 minutes or after morphine administration. This finding is MOST consistent with:
Correct answer: C - Acute cholecystitis
When preparing a Tc-99m MAA lung perfusion study, the number of administered particles should be REDUCED in a patient with a known:
Correct answer: A - Right-to-left cardiac shunt
During a regadenoson (Lexiscan) pharmacologic stress study, a patient develops severe bronchospasm and chest tightness. Which medication is used to REVERSE these effects?
Correct answer: D - Aminophylline
Practice hundreds more NMTCB questions with instant scoring, weak-area drills, and full exam simulations.