Part 5: Pediatric and bio effects Flashcards
For kids, you must collimate ___ only and not ___.
Area of interest only
NOT the entire image intensifier field
___mm film is usually used for peds cine film (esp cardiac exams)
35mm
For peds, do you generally want to include or omit grids?
Omit
(they increase pt radiation dose)
Those in the room exposed to x-rays are recommended to wear a protective apron of ___mm lead equivalent, and are required to be at least ___mm.
0.5mm
0.25mm
2 classes of biological effects of radiation exposure
Somatic
Genetic
Examples of somatic effects of radiation exposure
injury to superficial tissues
induction of cancer
injury to fetus/embryo
cataract formation
In diagnostic radiology,is the dose measurement at a single anatomical point expressive of the total somatic effect?
No
Bc one anatomical area was targeted only, others spared
Which type of cell is most affected by bone marrow exposure to radiation?
lymphocytes
Which studies give the higher bone marrow doses?
barium enema
upper GI series
abdominal angio
What are genetic dose effects from radiation exposure?
Those seen in future offspring of the persons who have been irradiated
***does NOT refer to embryo/fetus that received direct irradiation
What is the BEIR report?
Discusses effects of radiation on the gonads of males and females
Acute radiation doses of ___ to the gonads may produce temporary sterility
30 rads
Which studies cause the most gonad radiation exposure?
barium enema
IVP
lumbar spine/hips/femur
What is the Genetically Significant Dose (GSD) defined as?
the gonad dose which, if received by the whole population, would be expected to produce the same total genetic effect on the whole population as the sum of the individual doses that are actually received
The GSD is a function of what 3 parameters?
number of future children
x-ray exam rate
mean gonad dose per exam
Biological effects from exposure to ionizing radiation are influenced by what 3 factors?
dose rate to the tissue exposed
total dose received by the tissue exposed
type of cell exposed
Following the initial radiation exposure, but before the first clinically detectable effects occur
latent period
short-term vs. long-term radiation effects
short: minutes, days, weeks later
long: years, decades, generations later
The law of Bergonie and Tribondeau states that the radiosensitivity of tissues depends on what 3 things?
- the number of undifferentiated cells it contains
- the degree of mitotic activity
- the length of time the cells stay in active proliferation
Radiation-induced mitotic delay in the life cycle of a cell is usually (reversible/irreversible).
reversible
Based on the law of B & T, which cells are the most radio sensitive?
blood forming organs (marrow, spleen)
GI tissue
developing embryonic tissue (esp 1st trimester)
What is the most sensitive cell type and the least sensitive cell type?
most: lymphocyte
least: muscle
Look at the list of cell types in order of most to least sensitive
lymphocytes/WBCs
RBCs/granulocyte
epithelial
endothelial
connective tissue
bone
nerve
brain
muscle
What is the only unique disease that is identifiable as caused by radiation exposure?
Radiation-induced cataracts (distinguishable from other cataracts)
Most frequently occurring radiation caused cancer and least occurring
Most: female breast
Least: bone
Look at the list of radiation induced cancers in order from most susceptible to least
female breast
thyroid
heme
lungs
GI
bone
Absorbed doses of ___ to the fetus could result in SAB.
In animal studies, doses as little as ___ could impact the embryo.
50 rads
10 rads
Optically clear protective lenses of ___mm lead equivalent reduce personnel eye radiation exposure by 85-90%.
0.25mm
