GXMO Exam Questions and Correct
Answers
Motion blurMotion blur - Answer-1. Movement of the patient or the x-ray tube during exposure results
in blurring of the radiographic image. This loss of radiographic quality, called motion blur, may result in
repeated radiographs and therefore should be avoided.
2. Patient motion is usually caused by motion blur. Suspend respiration for exposures, decrease
exposure time, use a large SID and use a small OID.
Transverse - Answer-across the table, at right angles to longitudinal.
Longitudinal - Answer-along the long axis of the table.
Primary X-ray Beam - Answer-The x-ray beam that leaves the tube and is unattenuated, except by air.
The direction and location are predictable and controllable.
X-ray source - Answer-the x-ray tube between the cathode and anode.
kVp - Answer-Measure of the maximum electrical potential across an x-ray tube (expressed in kilovolts).
mA - Answer-Measure of x-ray tube current
,Remnant Radiation - Answer-X-rays that pass through the patient and interact with the image receptor
Scatter Radiation - Answer-X-rays scattered back in the direction of the incident x-ray beam
Penetrate - Answer-ability to pass through an object. Related to the x-ray quality
Absorb - Answer-to soak up. Absorption of x-rays results in energy being scattered or converted into
new scatter x-rays.
Attenuation - Answer-the total reduction in the number of x-rays remaining in an x-ray beam after
penetration through a given thickness of tissue
X-ray attenuation - Answer-When a broad beam of x-rays is incident of any tissue, some of the x-rays are
absorbed and some are scattered. The result is a reduced number of x-rays.
Differential attenuation - Answer-X-rays can penetrate matter that is opaque to light. This penetration is
differential, depending on the mass density and thickness of the matter
Basis for subject contrast - Answer-i. determined by the size, shape, and x-ray attenuating characteristics
of the subject who is being examined and the energy of the x-ray beam
Subject contrast - Answer-the range of differences in the intensity of the x-ray beam after it exists the
patient. It is affected by the kVp and the tissue density
Effects on air, bone, muscle and fat - Answer-i. X-rays penetrate air very readily. There is less
penetration of fat or oil, even less of water, which has about the same mass as muscle tissue, and still
less of bone.
, Intensity - Answer-The intensity of the x-ray beam of an x-ray imaging system is measured in milligray in
air (mGya) and is called x-ray quantity.
Effects on intensity (quantity) of the x-ray beam on the radiographic image - Answer-i. X-ray intensity is
proportional to mAs.
ii. X-ray intensity is proportional to kVp2.
iii. X-ray intensity is inversely proportional to the square of the distance from the source.
X-rayintensityisreducedwhenfiltrationisadded
Extremity - Answer-soft tissue and bone / low kV = high contrast (short scale) kVp 50 - 70
Abdomen - Answer-organs, air, fluid, and bowel patterns /low subject contrast / kVp: 75 to 90
Chest - Answer-Many structures to evaluate with different densities: lung, ribs, heart, and mediastinum
high subject contrast / high kVp = low contrast (long scale) / kVp 100 - 120
Radiographic film - Answer-Base and the emulsion
Base - Answer-i. the foundation of radiographic film that provides a rigid structure onto which the
emulsion can be coated.
ii. The original was a glass plate. Replaced by cellulose nitrate which was flammable. Replaced by
cellulose triacetate "safety base."
Answers
Motion blurMotion blur - Answer-1. Movement of the patient or the x-ray tube during exposure results
in blurring of the radiographic image. This loss of radiographic quality, called motion blur, may result in
repeated radiographs and therefore should be avoided.
2. Patient motion is usually caused by motion blur. Suspend respiration for exposures, decrease
exposure time, use a large SID and use a small OID.
Transverse - Answer-across the table, at right angles to longitudinal.
Longitudinal - Answer-along the long axis of the table.
Primary X-ray Beam - Answer-The x-ray beam that leaves the tube and is unattenuated, except by air.
The direction and location are predictable and controllable.
X-ray source - Answer-the x-ray tube between the cathode and anode.
kVp - Answer-Measure of the maximum electrical potential across an x-ray tube (expressed in kilovolts).
mA - Answer-Measure of x-ray tube current
,Remnant Radiation - Answer-X-rays that pass through the patient and interact with the image receptor
Scatter Radiation - Answer-X-rays scattered back in the direction of the incident x-ray beam
Penetrate - Answer-ability to pass through an object. Related to the x-ray quality
Absorb - Answer-to soak up. Absorption of x-rays results in energy being scattered or converted into
new scatter x-rays.
Attenuation - Answer-the total reduction in the number of x-rays remaining in an x-ray beam after
penetration through a given thickness of tissue
X-ray attenuation - Answer-When a broad beam of x-rays is incident of any tissue, some of the x-rays are
absorbed and some are scattered. The result is a reduced number of x-rays.
Differential attenuation - Answer-X-rays can penetrate matter that is opaque to light. This penetration is
differential, depending on the mass density and thickness of the matter
Basis for subject contrast - Answer-i. determined by the size, shape, and x-ray attenuating characteristics
of the subject who is being examined and the energy of the x-ray beam
Subject contrast - Answer-the range of differences in the intensity of the x-ray beam after it exists the
patient. It is affected by the kVp and the tissue density
Effects on air, bone, muscle and fat - Answer-i. X-rays penetrate air very readily. There is less
penetration of fat or oil, even less of water, which has about the same mass as muscle tissue, and still
less of bone.
, Intensity - Answer-The intensity of the x-ray beam of an x-ray imaging system is measured in milligray in
air (mGya) and is called x-ray quantity.
Effects on intensity (quantity) of the x-ray beam on the radiographic image - Answer-i. X-ray intensity is
proportional to mAs.
ii. X-ray intensity is proportional to kVp2.
iii. X-ray intensity is inversely proportional to the square of the distance from the source.
X-rayintensityisreducedwhenfiltrationisadded
Extremity - Answer-soft tissue and bone / low kV = high contrast (short scale) kVp 50 - 70
Abdomen - Answer-organs, air, fluid, and bowel patterns /low subject contrast / kVp: 75 to 90
Chest - Answer-Many structures to evaluate with different densities: lung, ribs, heart, and mediastinum
high subject contrast / high kVp = low contrast (long scale) / kVp 100 - 120
Radiographic film - Answer-Base and the emulsion
Base - Answer-i. the foundation of radiographic film that provides a rigid structure onto which the
emulsion can be coated.
ii. The original was a glass plate. Replaced by cellulose nitrate which was flammable. Replaced by
cellulose triacetate "safety base."
