XRAY FINAL FIXED

What is never imprinted on a patient's x-ray?

Social Security number

What is the densest tissue in our bodies?

Bone

How does bone display on the radiograph?

Bright/white

What does the central ray not being perpendicular to the body part affect?

Shape distortion

What is the purpose of a collimator?

Reduce dose by restricting the beam to the area of interest. (limit scatter and increase image contrast.)

What types of x-rays does filtration remove?

Low energy x-rays that add to skin dose.

70 kVp is how many volts?

70,000

What are the four variables to create an image?

mA, time, kVp, and SID.

Name 5 properties of x-rays.

Travel in straight path, neutral, massless, invisible, polyenergetic beam, cannot be focused, can be absorbed or scattered, cause damage to tissue.

What is the final x-ray image called that remains in a patient's medical file?

Manifest image.

365 msec is how many seconds?

0.365 seconds

What is scatter radiation?

Radiation that interacts with the patient's tissue, loses energy, and emerges in a different direction. If it reaches the IR it will produce a graying called fog.

What is the purpose of fluoroscopy?

To evaluate anatomy in real time.

Where is the x-ray tube located in fluoroscopy?

Under the table.

What is the device above the patient in fluoroscopy called?

II/fluoroscope.

What is another name for primary radiation?

Incident or useful beam.

Where does primary radiation come from?

The x-ray tube window.

What factors influence differential absorption?

kVp, tissue density, patient factors.

What are the three requirements to create x-rays?

Source of electrons, accelerate electrons, and stop electrons.

What do mA and exposure time determine?

Quantity of x-rays.

What is the relationship between mAs and dose?

Directly proportional.

Where are electrons created inside the x-ray tube?

When kV is applied to the tube, the electrons will travel very fast to the focal spot on the anode target; gets converted to heat and x-ray.

Where are x-rays created?

Focal spot of target on anode in the cathode filament.

What is the negative side of the x-ray tube called?

Cathode.

What is the positive side of the x-ray tube called?

Anode.

What is the energy that produces negative and positive ions called?

Ionizing radiation.

What radiation is emitted from the metal housing other than through the window?

Leakage.

What does the acronym SID stand for?

Source to image receptor distance.

What does the acronym OID stand for?

Object to image receptor distance.

What is exit radiation also called?

Remnant beam.

What area type of radiation in radiography contributes most to patient dose?

Photoelectric absorption.

What is the time for 60 mAs at 100 mA?

0.6 seconds.

What is the mA value for 40 mAs at ¼ sec?

160 mA.

What controls the quality of the x-ray beam?

kVp.

What are the five factors affecting image quality?

Exposure, brightness, contrast, spatial resolution, distortion.

Which three factors are considered photographic properties?

Exposure, brightness, contrast.

Which two factors are considered geometric properties?

Spatial resolution and distortion.

What is the difference between brightness levels called?

Contrast.

What is the most detrimental effect on image contrast?

Scatter.

What color appears in the image due to insufficient brightness?

White.

What types of radiation cause attenuation?

Absorption and scatter.

What is the smallest object that can be distinguished on a radiograph?

Spatial resolution.

If 50 mR was used at 72 inches, what is the new intensity at 50 inches?

104 mR.

If the exposure is 100 mR at 40 inches, what would be the exposure at 60 inches?

44 mR.

Which factor produces the BEST spatial resolution?

Short OID.

What is the purpose of grids?

Absorb scatter and increase contrast.

What necessitates the use of a grid?

Thicker body parts and higher kV.

What influences contrast in imaging?

Computer processing, anatomic part, use of contrast media, and kVp.

Describe high contrast using terms from the lecture.

b/l, short scale.

What is true about the larger matrix on the monitor?

The better the image resolution.

What is sometimes used advantageously in imaging?

Distortion.

What type of radiation produces the light areas on the radiograph?

Absorbed.

What factors affect absorption?

kVp, tissue type, patient factors.

What type of radiation contributes to occupational exposure?

Scatter.

What is any medium or device that captures the remnant beam called?

IR.

1. Brightness of the x-ray image depends on?

The anatomic part and computer processing.

What body region is high in subject contrast?

Chest

1. CR uses what as the IR/DR uses what as the IR?

IP/Detectors