5. Measurements with the Barracuda System
Fluoroscopy and Pulsed Fluoroscopy
2012-10/4.3A
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Barracuda & QABrowser Reference Manual
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 Barracuda system detects and
compensates automatically for a change of beam filtration. See Specifications, MPD
, for details of the range of beam filtration.
5.5.4 Pulsed Fluoroscopy
Select type of measurement in similar way as for normal continuously fluoroscopy to
setup the system.
Barracuda 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
The following pictures illustrates how the Barracuda system is used this type of
measurement.
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