Nucs Mechanism of Localization

Question 1

Passive Diffusion

Answer 1

• Tc-Sestamibi - Cross the cell membrane via lipophilic diffusion
• Tc-Tetrofosmin - Cross the cell membrain via lipophillic diffusion
• Tc-HMPAO - Delivery is flow related - then diffuse into the brain
• Tc-ECD - Delivery is flow related - then diffuse to brain

Question 2

Filtration

Answer 2

DTPA

Question 3

Facilitated Diffusion

Answer 3

F18 - FDG

Question 4

Active Transport

Answer 4

• I-123/I-131 (use ATP to move AGAINST concentration gradient)
• Thallium (Na/K Pump)
• Rubidium (Na/K Pump)
• MIBG (Na facilitated NE uptake system)
• DMSA

Question 5

Secretion

Answer 5

• Pertechnetate (active transport out of gland or tissue)
• MAG-3 (gets “threecreated” by peritubular capillaries)
• Tc-99m IDA (secreted by hepatocytes)

Question 6

Phagocytosis

Answer 6

Sulfur colloid (RES ears colloid particles)

Question 7

Sequestration

Answer 7

Head Treated RBCs

Question 8

Capillary Blockade

Answer 8

MAA (lung perfusion)

Question 9

Chemisorption

Answer 9

• MDP (Chemical covalent + H-bonding)
• SM-153

Question 10

Cellular Migration

Answer 10

In-WBC

Question 11

Receptor Binding

Answer 11

• Octreotide
• Ga-68 DOTATATE
• DAT Scan (I-123 Isoflupane)