NMTCB Pharmaceutical & Radiopharmaceutical Agents 4

Question 1

Tc-99m MAA particles used for lung perfusion imaging should be sized between:

Accepted Answer

10-90 µm

Answer

Tc-99m macroaggregated albumin (MAA) particles are 10-90 µm in diameter, large enough to lodge in pulmonary capillaries (7-10 µm) for perfusion imaging.

Question 2

Which agent is used for hepatobiliary imaging to evaluate acute cholecystitis?

Accepted Answer

Tc-99m mebrofenin (DISIDA)

Answer

Tc-99m mebrofenin (a hepatobiliary iminodiacetic acid/HIDA analogue) is extracted by hepatocytes and excreted into bile, allowing evaluation of gallbladder filling and biliary patency.

Question 3

Which radiopharmaceutical requires thyroid blocking prior to administration to prevent thyroidal uptake?

Accepted Answer

I-123 MIBG

Answer

Free iodide released from I-123 MIBG can be taken up by the thyroid; Lugol's solution or potassium iodide is given beforehand to block thyroid uptake.

Question 4

Tc-99m oxidronate (HDP) and Tc-99m MDP are used for bone imaging primarily due to their:

Accepted Answer

Chemisorption onto hydroxyapatite crystals at sites of osteoblastic activity

Answer

Diphosphonate agents chemisorb onto calcium hydroxyapatite at sites of increased osteoblastic activity and new bone formation.

Question 5

Which PET radiopharmaceutical is used to assess myocardial viability by evaluating fatty acid metabolism?

Accepted Answer

C-11 palmitate

Answer

C-11 palmitate is a radiolabeled fatty acid that is metabolized by viable myocardium via beta-oxidation, allowing assessment of myocardial fatty acid utilization.

(NMTCB) Nuclear Medicine Technology Certification Board Practice Test

(NMTCB) Nuclear Medicine Technology Certification Board Practice Test

NMTCB Pharmaceutical & Radiopharmaceutical Agents 4