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5. Measurements with the Piranha System
Fluoroscopy and Pulsed Fluoroscopy
Piranha & QABrowser Reference Manual
2014-06/5.5C
110
Furthermore, if the parameter "All w. TF+HVL" is chosen, the QABrowser will display
both estimated total filtration and quick-HVL values for every measurement shown
above.
Conclusion:
For the first time, trustable kV and filtration measurements can be made on an X-ray
unit. This is of special interest where the filtration not easily can be measured with a
conventional HVL method or the filtrations actually is changed during the fluoro
exposure or actually even not are known before.
Most other invasive kVp meters have a correction for the kVp of around 5 to 10 kV for a
change of the beam filtration of 10 mm Al. The correction graphs given, does not help if
the actual beam filtration are not known. The Piranha system detects and compensates
automatically for a change of beam filtration. See
Specifications, Piranha
, for details
of the range of beam filtration.
5.4.4
Pulsed Fluoroscopy
Select type of measurement in similar way as for normal continuously fluoroscopy to
setup the system.
Piranha is set-up for this application to calculate the number of pulses per second (Hz
or pps), the dose/pulse, and pulse dose rate. The picture below explain the difference
between the pulse dose rate and the traditional dose rate.
(Note that for DC waveform, pulse dose rate and dose rate gives the same value.)
When measuring tube voltage on pulsed fluoroscopy there is an additional waveform
type available. This waveform type is called
pulsed
and is recommended for pulsed
fluoroscopy measurements, especially if the pulses are not square wave shaped, since
this can result in low tube voltage readings.
Example of measurement on pulsed fluoroscopy
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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 ...