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8. Glossary
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Piranha & QABrowser Reference Manual
housing to control the "ON" or "OFF" condition of the useful beam.
Sievert (Sv)
The special name for the SI unit of dose equivalent. One sievert equals one joule per
kilogram. The previously used unit was the rem. One sievert is equal to 100 rem.
Signal-to-noise ratio
For video cameras, the ratio of input signal to background interference. The greater the
ratio, the clearer the image.
Simulator
Diagnostic energy X-ray equipment used to simulate a therapy treatment plan outside
the treatment room.
Slice
The single body section imaged in a tomography procedure.
Source
See radiation source.
Source-detector distance (SDD)
The distance measured along the central ray from the centre of the front surface of the
source (X-ray focal spot or sealed radioactive source) to the active surface of the
detector.
Source-to-image-distance (SID)
The distance measured along the central ray from the centre of the front of the surface
of the source (X-ray focal spot of sealed radioactive source) to the surface of the image
detector.
Source-surface distance (source-skin distance) (SSD)
The distance measured along the central ray from the centre of the front surface of the
source (X-ray focal spot or sealed radioactive source) to the surface of the irradiated
object or patient.
Spot film
A radiograph taken during a fluoroscopic examination for the purpose of providing a
permanent record of an area of interest of to verify the filling of a void with contrast
media.
Stray radiation
The sum of leakage and scattered radiation.
Survey
See radiation protection survey.
Target
The part of an X-ray tube anode assembly impacted by the electron beam to produce
the useful X-ray beam.
Tenth value layer (TVL)
Thickness of a specified substance which, when introduced into the path of a given
beam of radiation, reduces the kerma rate to one-tenth of its original rate.
Tomography
A special technique to show in detail images of structures lying in a predetermined
Summary of Contents for Piranha
Page 1: ...Reference Manual English Version 5 5C Piranha QABrowser RTI article number 9629050 10 ...
Page 8: ...Introduction Chapter 1 ...
Page 12: ...Description of the Piranha Chapter 2 ...
Page 40: ...Description of the QABrowser Chapter 3 ...
Page 77: ...Measurement Principles Theory Chapter 4 ...
Page 91: ...Measurements with the Piranha System Chapter 5 ...
Page 151: ...Optional Accessories Chapter 6 ...
Page 155: ...Problems and Solutions Chapter 7 ...
Page 161: ...Glossary Chapter 8 ...
Page 181: ...Notes Piranha QABrowser Reference Manual 2014 06 5 5C Notes 177 ...