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Projection - Describes the path of the x-ray beam.

Anode Heel Effect - Some x-rays are absorbed in the heel of the anode on the anode side of the tube resulting in a more intense beam on the cathode side of the tube.

Spinning Top Test - Measures the accuracy of the machine's timer.

Lead Apron - Must be no less than .25 mm lead equivalence, but most aprons are .5 mm lead equivalence as this provides more adequate protection.

Cell Damage - Discussed in terms of somatic changes (damage to the cell itself) and genetic changes (damage to the cell's DNA).

Sources of Ionizing Radiation - Natural - 82% / Made by man - 18%

Photoelectric Effect - Results in absorption of the x-ray photon - helps to provide contrast.

Compton Effect - Results in scatter radiation which provides nu useful information.

Linear Energy Transfer (LET) - Equates to the amount of damage that radiation does as it travels through tissue. Higher energy radiation has a higher LET and is capable of doing more harm as it travels through tissue.

ALARA - As low as reasonably achievable is a concept that encourages safe radiation practices in the field of radiography.

National Council on Radiation Protection and Measurements (NCRP) - Provides key information in determining dose limits.

Linear-Nonthreshold - No level of exposure is safe, and the degree of response is directly proportional to the degree of exposure received.

Law of Bergonie and Tribendeau - Cells are most sensitive to radiation when they are immature, undifferentiated, and rapidly dividing.

Oxygen Enhancement Ratio - Cells that are more oxygenated are more sensitive to radiation damage.

Blood Cells - A whole body dose of 25 rads depresses blood count.

Beam Limitation - Protects the patient by limiting the area of the body and the volume of tissue that is exposed.

Filtration - Filtration is responsible for removing lower energy photons which would only increase the patient's dose. Total filtration is the combination of added and inherent filtration in the unit. Total filtration must equal 2.5 mm aluminum equivalency.

Gonadal Shielding - Will reduce female gonadal exposure by 50%, and male gonadal exposure by 95%.

Fluoroscopy Fact - Source to table distance must be no less than 15 inches. The requirement is 12 inches for mobile fluoroscopy.

Fluoro Timer - Must sound alarm at 5 minutes of exposure.

Primary Protective Barrier - At least 1/16-inch lead equivalent and must extend up the wall 7 feet.

Secondary Protective Barrier - At least 1/32-inch equivalent. Must overlap primary barrier by 1/2-inch and extend up to the ceiling.

X-ray Tube Housing - Leakage radiation must not exceed 100mR per hour at a distance of 1 meter from the housing itself.

Fluoro Equipment - Protective curtain - 0.25 mm lead equivalence / Bucky slot cover - 0.25 mm lead equivalent.

Portable Unit - Exposure switch cord must be no less than 6 feet long.