Nuclear Medicine Flashcards
What nuclear medicine sign is associated with an osteoid osteoma on a bone scan
Double density sign or “hotter spot within hot area” sign
Physical half life of F18-FDG
110 minutes
What measures biologic damage caused by ionizing gamma radiation?
Roentgen equivalent man (REM) - term for dose equivalence and equals the biologic damage caused by 1 radiation absorbed dose (RAD).
Means not all types of radiation are equally effective in producing biological change or damage. Damage from 1 RAD deposited from beta is less than 1 rad of alpha radiation.
Physical half life of I-123 NaI?
13 hours
PET radiotracer useful for primary and metastatic well-differentiated neuroendocrine tumors
Ga-68 dotatate
Normal for uptake to be seen in the pituitary gland, spleen, liver, adrenals and urinary tract
What medication is given prior to an I-123 MIBG scan?
Potassium iodide (SSKI) or Lugols
Physical half life of Xe-133?
5.3 days
What measures the strength of radiation exposure in air from gamma ray radiation?
Roentgen is a measure of exposure to x-ray or gamma ray radiation.
The SI unit for absorbed dose is?
gray (Gy) but “RAD” or radiation absorbed dose is also commonly used
How is effective half life calculated? (equation)
1/Teffective = 1/Tphysical + 1/Tbiological.
Example: As in the case of ventilation imaging with Xe-133, where the biological half-life (~ 5 minutes) is much shorter than the physical half-life (5.2 days), the effective half-life will be closer to the biological half-life.
Half life of Tc-99m
6 hours
What is the physical half-life of Ga-67 citrate?
78 hours
Ga-67 half life and photopeaks?
Ga-67 has a half-life of 78 hours.
-Principal photopeaks of 93, 184, 296, and 388 keV. An easy way to remember Ga-67 photopeaks is “90, 190, 290, 390”,
Gallium energy peaks (4)
90, 190, 290, 390
In a younger patient, incidental finding
Bronchial atresia is a developmental anomaly characterized by focal obliteration of the proximal segment of a bronchus associated with hyperinflation of the distal lung.
On imaging, it commonly presents as a proximal focal tubular-shaped opacity radiating from the hilum associated with a distal area of hyperlucent lung parenchyma.
