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Question 1

Tc-99m sulfur colloid particles are predominantly removed from circulation by which organ?

Accepted Answer

Liver (60-90%), spleen, and bone marrow via phagocytosis

Answer

Tc-99m sulfur colloid is phagocytized by reticuloendothelial cells (Kupffer cells) in the liver (60-90%), with the remainder taken up by spleen and bone marrow.

Question 2

What is the primary route of excretion for Tc-99m DTPA after IV administration?

Accepted Answer

Glomerular filtration by the kidneys

Answer

Tc-99m DTPA is a small hydrophilic chelate that is freely filtered at the glomerulus and excreted in the urine without tubular secretion or reabsorption.

Question 3

Which radiopharmaceutical is used to assess gastric emptying rate?

Accepted Answer

Tc-99m sulfur colloid in scrambled eggs

Answer

Tc-99m sulfur colloid mixed into scrambled eggs is the standardized solid-phase gastric emptying meal per the Society of Nuclear Medicine protocol.

Question 4

Samarium-153 EDTMP is used therapeutically for which condition?

Accepted Answer

Painful bone metastases

Answer

Sm-153 EDTMP (lexidronam) localizes in bone metastases via hydroxyapatite binding and delivers beta radiation to palliate metastatic bone pain.

Question 5

The aluminum ion breakthrough test on a Tc-99m generator eluate ensures that aluminum concentration does not exceed:

Accepted Answer

1 µg/mL (1 ppm)

Answer

USP limits aluminum ion in Tc-99m eluate to no more than 10 µg Al per mL, but the standard limit commonly cited and tested is ≤10 µg/mL; the regulatory limit is ≤10 µg Al/mL eluate.

(NMTCB) Nuclear Medicine Technology Certification Board Practice Test

(NMTCB) Nuclear Medicine Technology Certification Board Practice Test

NMTCB Pharmaceutical & Radiopharmaceutical Agents 3