Nuclear: High Yield Flashcards
What is the critical organ?
The organ that receives the most concerning dose of radiation (this is the organ that limits the dose of the radiopharmaceutical used for that particular study)
Note: This is typically the organ that the radiotracer spends the most time in.
What is the target organ?
The organ you want a radiotracer to accumulate in
Critical organ for In-111 PSMA
Liver
Critical organ for I-131 MIBG
Liver
Note: For I-123 MIBG, its bladder.
Critical organ for IV Tc-99m sulfur colloid
Liver
Critical organ for Tc-99m HIDA
Gallbladder wall
Critical organ for thallium-201
Renal cortex
Critical organ for Tc-99m DMSA
Renal cortex
Note: Structural renal agents stay in the kidney longer than the bladder.
Critical organ for PO Tc-99m sulfur colloid
Proximal colon
Critical organ for Tc-99m sestamibi
Proximal colon
Critical organ for Tc-99m MAG3
Bladder
Note: Functional renal agents stay in the bladder longer than the kidney.
Critical organ for Tc-99m MDP
Bladder
Note: Some people think its actually bone.
Critical organ for I-123 MIBG
Bladder
Note: For I-131 MIBG, its liver.
Critical organ for In-111 octreotide/pentetreotide
Spleen
Critical organ for Tc-99m RBCs
Undamaged RBCs: Heart
Heat-damaged RBCs: Spleen
Critical organ for In-111 WBC
Spleen
Critical organ for Tc-99m pertechnetate
Stomach
Critical organ for gallium-67
Distal colon
Critical organ for Tc-99m DTPA
Bladder
Note: Functional renal agents stay in the bladder longer than the kidney.
Thallium-201 is an analog of…
Potassium (enters cells by Na/K ATPase)
Gallium-67 is an analog of…
Iron
What are the photon energies released by Tc-99m?
Low:
140 keV
What are the photon energies released by I-123?
Low:
159 keV
What are the photon energies released by Xenon-133
Low:
81 keV
What are the photon energies released by Thallium-201?
Low:
- 135 keV (2%)
- 167 keV (8%)
Note: It is the photon energies released by thalliums daughter product (mercury-201) that are used for imaging. Mercury-201 actually gives off x-rays.
What are the photon energies released by Indium-111?
Medium:
- 173 keV (89%)
- 247 keV (94%)
What are the photon energies released by Gallium-67?
Multiple:
- 93 keV (40%)
- 184 keV (20%)
- 300 keV (20%)
- 393 keV (5%)
What are the photon energies released by Iodine-131?
High:
365 keV
What are the photon energies released by Fluorine-18?
High:
511 keV
Note: 2 high energy 511 keV photons are released during the annihilation process.
Physical half life of Tc-99m
6 hours
Physical half life of Iodine-123
13 hours
Physical half life of Xenon-133
125 hours
Note: The biological half life is 30 seconds (because it is breathed out).
Physical half life of Thallium-201
73 hours
Physical half life of Indium-111
67 hours
Physical half life of Gallium-67
78 hours
Physical half life of Iodine-131
8 days
Physical half life of Fluorine-18
110 minutes
Physical half life of Strontium-89
50.5 days (14 days in bone)
Physical half life of Samarium-153
46 hours
Physical half life of Radium-223
11 days
Physical half life of Yttrium-90
64 hours
Physical half life of Rubidium-82
75 seconds
Physical half life of Nitrogen-13
10 minutes