Math
A radiograph is made with a 36 inch SID resulting in a receptor exposure of 0.01 mGy. What will the receptor exposure be if the SID is changed to 72 inches?
0.0025 mGy
The diastolic blood pressure is a measurement of the pressure exerted on the arterial walls during:
Relaxation of the left ventricle
A radiograph of the shoulder is produced using 12 mAs and 75 kVp at the wall bucky. How could the technique be changed to decrease contrast while maintaining the same receptor exposure?
6 mAs, 87 kVp
Which component of an indirect capture flat-panel detector converts incident x-ray photons into visible light photons?
Scintillation layer
Subject contrast in radiography refers to the:
Magnitude of signal difference in the remnant beam
A satisfactory x-ray of the thoracic spine is made at 60 inches using automatic exposure control. The exposure time was 100 milliseconds. If the exam is repeated at 40 inches, what will the new exposure time be?
44 milliseconds
The movement of electrical impulses through ventricles is represented by which segment of the electrocardiogram EKG pattern?
QRS complex
An x-ray of the chest uses a 72 inch SID. If the image of the heart measures 12cm and the actual heart measures 7cm, what is the magnification factor?
1.7
Which element used in the construction of a flat-panel detector is able to convert x-ray photons directly into an electrical signal?
Amorphous Selenium
How does an air filled bowel obstruction affect the subject contrast of the abdomen?
increased subject contrast
The breasts of a radiation worker are exposed to an absorbed dose of 10 mGy from a gamma emitting radionuclide. Calculate the effective dose if the radiation weighting factor is 1.0 and the tissue weighting factor for the breasts is 0.12
1.2 mSv
A glomerular filtration rate test would provide information on:
Rate at which the kidneys filter waste from the blood
Calculate the focal spot blur for a radiograph acquired using 40 inch SID, 2 inch OID, and a 0.1 inch Focal spot size.
0.0053 inches
What is created on an image receptor by the arrangement of detector elements into rows and columns?
Matrix
How does increasing window width affect the displayed image?
Decreased contrast
Which combination of variables will result in a radiograph with the lowest receptor exposure?
A)100 kVp, 50 mAs, 14x17 receptor
B)85 kVp, 100 mAs, 10x12 receptor
C)75 kVp, 50 mAs, 14x17 receptor
D)85 kVp, 25 mAs, 10x12 receptor
D
Iodine contrast media is made less toxic and more tolerable to the human body by what method?
binding the iodine atoms to a benzene ring
A technologist acquires an x-ray of the pelvis using 100 kVp, 10 mAs, 40 inches SID, and a no grid. The exposure level is good, but the contrast is to low. If the exam is repeated using a 16:1 grid, what new technique should be employed?
100 kVp and 60 mAs
How many shades of gray can be displayed by an 8-bit digital radiography system?
256 shades
How is the Source to object distance calculated (SOD)?
Source to image distance (SID)- Object to image distance (OID)
If a radiograph is produced using a mA of 400 and 0.05 seconds, how should the exposure time be changed of the mA is decreased to 200?
0.10 seconds
What is the main reason barium is combined with a sulfate molecule for use as a contrast media?
It lessens the toxicity of barium by forming a non-water soluble solution.
Calculate the heat produced by a 3- phase 6- pulse x-ray machine using a 70 kVp and 7 mAs.
662 heat units
What type of noise cannot be reduced?
Ambient
What is the relationship between source to image distance and size distortion?
Size distortion decreases with a longer SID