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RTI Piranha Reference Manual Download Page 88

4. Measurement Principles & Theory
HVL & Total Filtration

Piranha & QABrowser Reference Manual

2014-06/5.5C

84

To measure the HVL:

1. Use the Piranha HVL stand on the table-top.

2. Set the generator to 80 kV/25 mAs.

3. If the display is unstable; press the Reset button.

4. Use some form to record your measurements.

5. Begin with 3 exposures without any added aluminum filter to get the zero-point and to

check the consistency of the generator.

6. Add the aluminum filters, 1, 2, 3, and 4 mm, and record the readings. Make a

measurement for each thickness and use the mean value.

7. Plot the results in a semi-logarithmic graph, set the value for 0 mm of added

aluminium to 1.0.

8. Join the measured points with a curve and find the value of added filtration required

to reduce the exposure to 0.5.

9. We find from the semi-logarithmic plot that the measured half-value layer is 3.3 mm

Al.

To measure Total Filtration:

In order to measure total filtration with one exposure optimally, there are some settings
to be aware of. Since the highest accuracy is obtained between 60 and 120 kV, we
recommend to do the measurement of the total filtration in between, at 80 kV. The
Piranha is also calibrated for the total filtration at this kV. Use a high signal level, i.e.
200 mA during 200 ms to get a stable result. It does not matter if you intend to do
measurements at a higher or lower kV than this, this measurement aim to get a correct
value of the total filtration.
See the graph below for optimum choice of method.

Hence, choose 80 kV, 200 mA and 200 ms and make an exposure. The total filtration
will be displayed in a pop-up screen. Tap

Keep

and the value is stored and will be used

on all further measurements. The pop-up screen will be displayed whenever the value of
the total filtration is changed.
Manually you can do this by entering the settings screen by tapping the

icon, as

shown below. As default value the total filtration is set to

Estimate

. Measure the total

filtration and then enter the settings window again. Now choose

Set

and enter the

measured value.

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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 2: ...Welcome to Piranha and the QABrowser The Piranha is an X ray Analyser Multimeter for everybody working with Quality Assurance and Service of X ray systems ...

Page 3: ...nited States RTI Electronics AB reserves all rights to make changes in the Piranha the QABrowser and the information in this document without prior notice RTI Electronics AB assumes no responsibility for any errors or consequential damages that may result from the use or misinterpretation of any information contained in this document Copyright 2001 2014 by RTI Electronics AB All rights reserved Co...

Page 4: ...ther steps in an examination but not an ongoing exposure for assessing the performance of the X ray equipment for evaluation of examination techniques and procedures for service and maintenance measurements for quality control measurements for educational purposes authority supervision etc The product is intended to be used by hospital physicists X ray engineers manufacturer s service teams and ot...

Page 5: ...ds and Compliances 29 2 5 1 Waste Electrical and Electronic Equipment WEEE 30 2 5 2 Manufacturer s Declaration of Conformity 31 2 5 3 Intended Use 32 2 5 4 FCC Certification 32 2 6 Maintenance 32 2 6 1 Updating the Piranha Firmware 35 2 6 2 Managing Detector Calibrations 3 37 Description of the QABrowser 37 3 1 Introduction to the QABrowser 37 3 2 Starting the QABrowser 38 3 3 Real time Display an...

Page 6: ... and Active Messages 78 4 4 1 Active Messages 80 4 4 2 Display Messages 82 4 5 Waveforms and Triggers 83 4 6 Measurement Principle for the Piranha 83 4 7 HVL Total Filtration 85 4 8 Linearity 86 4 9 Reproducibility 5 88 Measurements with the Piranha System 88 5 1 Introduction 89 5 2 Radiography 91 5 2 1 kVp Time Dose and Dose Rate 94 5 2 2 Dose Measurements with Piranha Dose Probe 95 5 2 3 HVL App...

Page 7: ... Scanning Beam Mammography 125 5 6 Dental and Panoramic Dental 128 5 6 1 kVp Time Dose and Dose Rate 130 5 6 2 Waveforms 131 5 6 3 Panoramic Systems 133 5 6 4 HVL Total Filtration and Quick HVL 134 5 7 CT 134 5 7 1 CT kVp 136 5 7 2 Parameters for CT Scanner Models 137 5 7 3 Quick HVL and Total Filtration 137 5 8 Tube Current Probes 138 5 8 1 MAS 1 Invasive mAs Probe 141 5 8 2 MAS 2 Non invasive mA...

Page 8: ...Introduction Chapter 1 ...

Page 9: ...are used to store calibration data and used by other products than the Piranha from RTI Electronics For the Piranha system calibration data is instead stored inside the system See section Managing Detector Calibrations for more information The handheld computer is sometimes called Palm or Palm computer in this manual this is referring to all types of handheld computers running Palm OS or Windows M...

Page 10: ...ng you are welcome to contact us at RTI Electronics at sales rti se You can of course also call or send a fax see notice section for details PC Requirements 1 3 To run the RTI Updater the QABrowser Updater and Ocean the following is required Minimum requirements Windows XP 2003 Vista 7 8 32 bit or 7 8 64 bit Pentium class 300 MHz 64 MB RAM 24 MB free 60 MB of HD 1 USB port Display and graphics car...

Page 11: ...1 Introduction Palm OS Computer Requirements 2014 06 5 5C 7 Piranha QABrowser Reference Manual RTI Handheld Display or Palm Tungsten E2 TX Bluetooth wireless ...

Page 12: ...Description of the Piranha Chapter 2 ...

Page 13: ...ld is 3 21 mm The recommended field size is shown as red corners 20 40 mm Power switch on edge Turns the Piranha on and off Indicators for charging status and Bluetooth USB Palm charger port output not used The USB port is used when using RTI Updater to update the internal firmware It can also be used when the Piranha is used together with a PC running the QA software Ocean Note that the USB conne...

Page 14: ...he status indicates for 3 seconds Green if battery level over 25 4 h left Yellow if battery level between 10 and 25 1 4 h left Red if battery level below 10 1 h left The idea is to get a quick indication when powering on the system if it will take me through today s work 2 When running on batteries the status indicator shows Status colour Running time left Green 2 hours Yellow 1 hours Red 15 minut...

Page 15: ... 0 Product marking Indicates the model of you Piranha as well as the version serial number and applicable conformity markings Camera thread for mounting the Piranha to a holder Attachment for Safety strap The Power switch is used to turn the Piranha on and off Piranha has several ways of saving power when it is inactive but must be powered off manually since there is no auto power off function Bel...

Page 16: ...d HVL stand for positioning of the Piranha in the X ray field The stand allows you to position the Piranha or the external Dose Probe and HVL filters in any angle including upside down Use the light field or other help to position the Piranha in the X ray field The Piranha detector is not sensitive for different field sizes as long as the entire sensitive detector area is irradiated but try to kee...

Page 17: ...adiographic fluoroscopic dental and CT exposures On pulsed radiation and cine also dose per pulse and pulse rate are measured The Piranha internal detector is very sensitive and can measure peak tube voltage for as low outputs as 50 kV 0 050 mA at 50 cm Typically the exposure time has to be at least 5 ms to get a kVp value but it depends on the waveform On modern X ray generators high frequency wi...

Page 18: ...80 12 h 2 h 150 min 6 h 27 h 90 13 h 3 h 195 min 7 h 30 h 100 15 h 5 h 300 min 8 h 32 h Note that other mains power solutions that uses a regular USB cable to connect to the Piranha will behave like USB in the table Communication USB Max 12 Mbit s USB v1 1 Bluetooth 115 kbit s 2 4 1 3 Specifications Piranha The inaccuracy is here defined as the root of the square sum of systematic errors which has...

Page 19: ...ation is done with field size typically 5 mm less than the size of the top panel Radiation quality Radiography Mammography CT 70 kV 2 5 mm Al 28 kV 30 µm Mo 120 kV 2 5 mm Al Note The reference conditions are given in reference to the IEC61674 standard Physical dimensions Detector area 3 21 1 mm Detector position 10 mm below top panel as indicated in figure below and by a 3 mm rim on 3 edges Size 1...

Page 20: ...ness of filtration Dose rate waveform Signal measured from radiation detector solid state detector Measuring range and inaccuracy Radiography Fluoroscopy and Dental Parameter RQ Range Inaccuracy Resolution kVp standard W 3 mm Al R1 35 160 kV 1 5 4 digits 10 or 100 V kVp dental W 3 mm Al R1 35 105 kV 1 5 As above Irradiation time 0 1 ms 2000 s 1 65535 pulses 1 or 0 5 ms 1 pulse 0 5 ms 1 pulse Air k...

Page 21: ... 5 or 0 7 kV 2 or 1 kV 2 or 1 kV 4 digits 10 V kVp optional Mo 30 µm Mo 2 mm Al Mo 2 0 mm Al M1d M2 25 35 kV 18 49 kV 2 or 1 kV 2 or 1 kV 4 digits 10 V Irradiation time 0 1 ms 2000 s 1 65535 pulses 1 or 0 5 ms 1 pulse 0 5 ms 1 pulse Air kerma Dose 1 with wide range option WR 5 µGy 1500 Gy 25 nGy 1500 Gy 3 µR 150 kR 5 5 Air kerma rate 1 Dose rate with wide range option WR 10 µGy s 750 mGy s 2 25 nG...

Page 22: ...W 50 µm Ag W 75 µm Ag W 50 µm Rh Gio W 0 70 mm Al W 50 µm Ag Sel W 50 µm Rh Sel M1 M3 M4 M6 M7 M8 M10 M11 M12 M15 M16 M17 0 19 0 47 mm Al 0 31 0 52 mm Al 0 33 0 60 mm Al 0 37 0 75 mm Al 0 24 0 64 mm Al 0 31 0 68 mm Al 0 34 0 69 mm Al 0 41 0 79 mm Al 0 37 0 66 mm Al 0 27 0 81 mm Al 0 34 0 69 mm Al 0 37 0 66 mm Al 10 3 digits 0 001 mm Note 6 The Quick HVL for mammography is only available for Piranh...

Page 23: ... Estimated total filtration C1 C6 1 5 90 mm Al 75 160 kV 10 or 0 3 mm 15 50 mm Al 75 120 kV HF DC 10 µGy s 2 digits 0 1 or 1 mm Quick HVL C1 1 2 14 mm Al 75 150 kV 10 or 0 2 mm 75 120 kV HF DC 10 µGy s 1 3 digits 0 01 or 0 1 mm Note 1 This is valid for a tube with 14 anode angle The HVL for a 22 anode is typically 0 5 mm lower 80 kV 3 mm TF Note 2 The C3 and higher numbered calibrations are only a...

Page 24: ... Sensitivity pulse width min dose rate 4 ms 4 µGy s 0 5 ms 30 µGy s 4 ms 20 µGy s 0 5 ms 160 µGy s Minimum ripple pulse top to bottom 50 Irradiation time 1 65535 pulses resolution 1 pulse Note 1 Max dose pulse depends on the pulse length Note 2 All kerma and kerma rate ranges inaccuracy and resolution figures are valid for product version 2 and higher of the Piranha Waveform recording time At max ...

Page 25: ...RQR 5 34 84 2 83 2 57 1 DV80 RQR 6 37 88 2 99 3 01 0 9976 DV90 RQR 7 41 1 3 18 3 48 0 9920 DV100 RQR 8 44 33 3 36 3 96 0 9920 DV120 RQR 9 50 86 3 73 5 00 0 9988 DV150 RQR 10 61 47 4 38 6 55 1 0199 Note These values are typical values measured at PTB in Germany in 2007 Radiation quality Mean energy air kerma keV Total Filtration mm Al Air kerma measurement PTB ISO 4037 IEC 61267 HVL mm Al Factor kQ...

Page 26: ... typical values measured at PTB in Germany in 2007 Mammography Mo 1 mm Al measured using RTI RQ Code M8 Radiation quality Mean energy air kerma keV Air kerma measurement PTB ISO 4037 IEC 61267 HVL mm Al Factor kQ Rel MAV28 MAV25 17 58 0 48 1 0033 MAV28 18 29 0 54 1 MAV30 18 66 0 56 0 9978 MAV35 19 36 0 61 0 9944 MAV40 19 89 0 64 0 9915 Note These values are typical values measured at PTB in German...

Page 27: ...6 97 0 40 1 WAV30 17 49 0 43 0 9974 WAV35 18 73 0 51 0 9928 WAV40 19 79 0 58 1 0028 Note These values are typical values measured at PTB in Germany in 2009 Mammography W 50 µm Rh measured using RTI RQ Code M6 Radiation quality Mean energy air kerma keV Air kerma measurement PTB ISO 4037 IEC 61267 HVL mm Al Factor kQ Rel WRV28 WRV25 17 6 0 48 0 9978 WRV28 17 99 0 51 1 WRV30 18 19 0 52 1 0009 WRV35 ...

Page 28: ... please see the polar plot shown below The Piranha is shown to the left and a typical mammographic ion chamber to the right There are two different graphs depending on the product version of your Piranha The product version is the version number you can find on the label on the bottom of the Piranha If the version of your Piranha is 1 X use the graphs marked v1 For 2 X and higher use graphs marked...

Page 29: ...2 Description of the Piranha Hardware and Specifications 2014 06 5 5C 25 Piranha QABrowser Reference Manual ...

Page 30: ...Measuring range and inaccuracy The detector noise given is typical values at room temperature Piranha External Dose Probe typical sensitivity 55 µC Gy Parameter Range Inaccuracy Typ noise Air kerma Dose 100 pGy 1 5 kGy 12 nR 170 kR 5 for time 0 1 ms Air kerma rate Dose rate 5 s moving average 4 nGy s 150 mGy s 460 nR s 16 R s 26 µR min 1000 R min 1 6 mR h 60 kR h 1 nGy s 150 mGy s valid for Irr ti...

Page 31: ... min sampling rate 524 s 4 Sa s A total of 8 recording times are available all separated by a factor of 2 i e 1 2 4 8 16 33 66 131 262 and 524 seconds The setting for Waveform recording time may affect the Irradiation time calculation Make sure to set back the Waveform recording time to the lowest choice after temporarily modifying it Please also note that in QABrowser the waveforms are limited to...

Page 32: ... also Waveforms and Triggers Piranha MAS 2 Probe Non invasive mAs probe sensitivity 1 nC mAs Module type Range Inaccuracy Typ noise Tube charge 0 1 mAs 5 for time 0 1 ms Tube current 10 4000 mA 5 or 2 mA for time 20 ms 3 at 250 mA 1 mA Pulse tube current Lower limit 50 mA otherwise same as tube current Time 1 0 1 ms 34000 s 1 65535 pulses 1 or 0 5 ms 1 pulse Resolution 0 5 ms Note 1 See also note ...

Page 33: ...d to finance the cost of recovery from municipal collection points reuse and recycling of specified percentages per the WEEE requirements Instructions for disposal of WEEE by Users in the European Union The symbol shown left is marked on the product which indicates that this product must not be disposed of with other waste Instead it is the user s responsibility to dispose of the user s waste equi...

Page 34: ...2 Description of the Piranha Standards and Compliances Piranha QABrowser Reference Manual 2014 06 5 5C 30 2 5 2 Manufacturer s Declaration of Conformity ...

Page 35: ...2 Description of the Piranha Standards and Compliances 2014 06 5 5C 31 Piranha QABrowser Reference Manual 2 5 3 Intended Use ...

Page 36: ...llow quick and easy update The RTI Updater with the latest firmware is always available free of charge on the RTI Electronics Web site at http www rti se To update your Piranha you must first download the latest version and install it on a PC The PC needs to have an USB port You will need to have access to an administrative account to install the software To update the Piranha firmware or bootload...

Page 37: ...ton is enabled Click Start If the Piranha cannot be found a message with suggested solutions is shown 7 The updating process starts The RTI Updater checks the current versions and compares with the update Modules with old firmware are automatically updated 8 Note that storing the new firmware in the flash memory may take several minutes for each module The RTI Updater will indicate which modules h...

Page 38: ...nics To re install firmware repeat step 1 to 9 above but before performing step 6 go to the menu Settings and select Always Overwrite If you want to see more details of what is updated use the menu Settings Advanced and you will see more information as shown in the figure below You normally also need to update the QABrowser and Ocean when you update the firmware See section Updating the QABrowser ...

Page 39: ...and click OK If no instrument appears check the communication cable and that the Piranha is powered on then click Rescan Next the available detectors are shown to the left The Internal detector is always available but external probes will only show up if they are attached When clicking a detector the available calibrations will show up to the right In this case the Internal detector is highlighted...

Page 40: ...Description of the QABrowser Chapter 3 ...

Page 41: ...ions for viewbox test and monitor test using the light detector The QABrowser also allow you to look at waveforms and log data The text in this section assumes that you purchased your Handheld Display either directly from RTI or a RTI dealer which means that QABrowser is already installed and configured on the Handheld Display If you have purchased your handheld on your own then you first need to ...

Page 42: ...Piranha as described in topic Setting Up the Piranha 3 3 1 Using the Real Time Display There are two main measuring modes Real Time Display RTD and Applications in the QABrowser We will first see how to use the RTD to measure different parameters and viewing waveforms Earlier in the topic Setting Up the Piranha was showed how to set up the Piranha system and how to start the QABrowser 1 A list wit...

Page 43: ...uality Depending on type of measurement you may have several kV ranges and beam qualities to choose from For radiography you have three different kV ranges 35 75 45 125 and 90 155 to select between You will have four displays on this screen if you do not have use a mAs probe and six if you selected to measure mAs The manual for the mAs probe explains how to connect it Change kV range by tapping he...

Page 44: ...o re position the detector For a small misalignment a correction factor is applied and you are allowed to continue without re positioning the detector This message disappears automatically if the position is OK If the displayed number is between 0 950 and 1 050 the position is acceptable and a correction factor will be applied to correct the position to 1 000 The correction factor is valid until y...

Page 45: ...ch exposure for all measurement types except mammography It is shown automatically after the first exposure If you want the QABrowser to lock this value and not estimate it again for the following exposures tap Keep You can also enter the total filtration manually under the settings see topic Settings for more information Up to six values can be shown simultaneously Measured kVp dose and dose rate...

Page 46: ...ke Up to three waveforms are simultaneously captured and visualized with the QABrowser The following waveforms can be measured depending on configuration and selected type of measurement tube voltage kVp with the Internal detector dose rate with the Internal detector dose rate with the external Dose Probe available for specific Piranha models tube current mA with the external Dose Probe available ...

Page 47: ...surement Settings As mentioned before all settings of the Piranha are done automatically when you select type of measurement For example when you choose fluoroscopy the detector sensitivity is set to high However there might be situations where the default settings cannot be used and settings must be adjusted Use Settings to adjust the Piranha when necessary The figure below shows how to access th...

Page 48: ...c settings for the Internal detector detector If your model of Piranha has an external probe that is attached it will also show here Piranha Shows general settings for the Piranha You can find information about the different parameters in Settings Piranha Internal detector Shows specific settings for the Internal detector detector as well as the serial number You can find information about the dif...

Page 49: ...es can be shown depending on selected measured parameter Conditions TF and Waveform These are parameters of the X ray generator which influence the measurements The Piranha can measure these or you can set them yourself Total Filtr Shows actual total filtration value Estimate means that a new estimation will be performed at next exposure and the values will be displayed on screen Waveform Shows th...

Page 50: ...e kV ripple from the AMX 4 Therefore it is important to select the AMX 4 waveform under Settings Conditions More about the AMX 4 correction can be found in the Application Note 1 AN 52020 1 from RTI Electronics AB Pulsed This waveform type should be used for pulsed fluoroscopy especially when the pulses do not have a good square waveform shape The exposure time must be longer than the selected rec...

Page 51: ...on is active an indicator on the RTD screen indicates that this feature is on Scatter factor If an ion chamber is positioned just below the compression paddle the measured dose will rise because of side scattering from the compression paddle material The effect of this is depending on the ion chambers angular dependence Since the Piranha is almost insensitive to this you can put a number here to c...

Page 52: ... same When this function is activated a red horisontal indicator will show in the top right corner of the RTD screen Here you can see an example of a holder that is used for some customers to replace ion chambers in ready made fixtures 3 3 3 2 Settings Piranha Here general measurement settings for the Piranha are shown Post Delay The post delay time defines how long time the Piranha shall wait and...

Page 53: ... irradiation time is then calculated as the end time minus the start time The start time is the first time the signal goes above TL SPEAK The end time is the last time the signal goes below TL SPEAK See example below Update This setting defines when Piranha shall send measured values to the QABrowser Four different alternatives are available After exp the QABrowser receives a new value when the ex...

Page 54: ...eforms need to be viewed See section Update Modes for more information The default value is set according to selected type of measurement see section Measurement Type Settings Start after delay When this is selected the waveform recoding will start after the set delay This can be useful if you want to study a phenomenon that occurs after the normal waveform recording time When this is selected the...

Page 55: ...l wait before starting to measure kVp after that radiation has been detected The delay can be set to Off 5 ms 25 ms 100 ms 500 ms 1 s 2 s or Other 0 9999 ms The default value is set according to selected type of measurement see section Measurement Type Settings Window This gives the possibility to define a fixed time that Piranha measures kVp after that the delay time has expired The window can be...

Page 56: ...en Low is used To avoid false triggering in a noisy environment use one of the higher threshold levels Normalize to distance Note Only for dose detectors If Normalize to distance is checked you have the option to normalize the dose reading to any given distance Here you can enter your Source to Detector Distance SDD and a normalizing distance SDD Norm that you want the dose normalized to When this...

Page 57: ...on 2 The Select application screen lists the available applications for selected Type of measurement and Selected parameter For kVp only Accuracy and Reproducibility are available Choose Accuracy by tapping it with the pen You can also use the scroll button to highlight Accuracy and then press the button that corresponds to Select the right most button 3 The accuracy application is shown on the sc...

Page 58: ...to the left of the graffiti area and select Options Edit Set Value List from the pull down menu You can now change delete insert values in the set value list for current application Use the graffiti area to enter new values Tap OK to save changes or Cancel to return to the application without changing the list 5 Make exposures according to the set values Measured values are shown and the inaccurac...

Page 59: ...n You can use the pen or buttons to move the cursor to view result for individual points 3 4 2 The Accuracy Application multi parameter It is also possible to test several parameters at the same time As an example Radiography All Accuracy is used 1 Tap Appl to activate the application screen 2 Available applications for Radiography All are shown Choose Accuracy by tapping it with the pen You can a...

Page 60: ... the bottom of the screen allowing input of a new set value Enter a new value using the pen on the graffiti area then tap OK Tap Cancel to leave without modifying the set value If you want to edit or view the complete set value list Then tap at the top of the screen or the Menu icon the lower icon to the left of the graffiti area and select Options Edit Set Value List from the pull down menu You c...

Page 61: ...osure 6 Perform all exposures in the list 7 You can look at the result graphically for each parameter tested Highlight a parameter by tapping it with the pen not the set value and then tap Graph or press the corresponding button The accuracy limits dotted lines in the graph are defined in the QABrowser Setup see topic QABrowser Setup Regulations Data Logging 3 5 The QABrowser can log data and save...

Page 62: ...e will be written to the log file each time the exposure indication is shown For Continuous update mode a value will be stored each time you tap the Hold button In applications the log values are stored when you exit the application This means that you can start the log after you have done your measurements and still get all data to the log If you want to pause the log temporarily just select Opti...

Page 63: ... the interface and find yourselves performing the same types of measurements over and over again you may desire to move between these types of measurements more quickly Instead of going up and down through the menu trees we found that users would like to move across the tree structure The desire was to find a solution for this need but still be able to keep the simplicity and intuitiveness of the ...

Page 64: ...asuring units and much more are saved with it If you save an application for example Accuracy even the set value list is saved That is both an Accuracy table for a Siemens generator with specific set values as well as another Accuracy specific for a GE generator can be saved When either of these new Favourites is selected you will have all the proper set values without having to change anything Th...

Page 65: ...hown Choose Options Add to Favourites The favourite must be saved in a group and a new group is created by tapping New Creating a group so that the favourite can be saved in this Saving a favourite in a certain group Mammo in this case The saved favourites can be found in the menu field tap Options and then Favourites To start the favourite that you are interested of you have to mark the favourite...

Page 66: ... stored in the Palm to a backup folder in the PC This folder can normally be found in C program files palmOne your palm name backup Note that program files varies depending on your Windows language version and your palm name is the name of your Palm device In this case the name of the Palm is T3MW In this folder you can find all the favourites in the groups where they were saved The group is saved...

Page 67: ...y use the QABrowser for measurement on radiography and that you use the real time display to display all values Go to the screen where you want the QABrowser to start Tap Start Here to select this screen as starting point for the QABrowser You can now quit the QABrowser Restart and verify that it starts up with selected screen Actually Start Here is a special case of the Favourites as described ab...

Page 68: ...raffiti area 2 You can change parameter by tapping the parameter name at the top of the screen 3 7 2 Units Setup Units Setup is used to change the preferred unit of measure for dose and dose rate as well as units for temperature and air pressure These are then the default units for all new tests Tap the unit you want to change and tap the desired unit in the list that pops up When measuring in the...

Page 69: ...n when it is not used and charging is off Stay on in Cradle defines that it should stay on as soon as it is connected to and powered from the Piranha Auto prompt is for the built in applications in multi parameter mode It defines how long time the result from one exposure is shown before the cursor moves on to the next position Lock unit prefixes means that the prefix of a unit is fixed and not au...

Page 70: ...al Number The serial number for the system Firmware Firmware version of the internal software that is used in the system Product v The product version is the hardware version This is the version printed on the product serial label 3 7 7 System Test System Test is used to test different functions in the Piranha system Beep generates a 2 second beep Play Melody plays the famous Swedish hit song The ...

Page 71: ...h the Piranha and the Palm you can monitor the charge level by the fill of the battery symbol See also Indicators and Connectors If the Piranha is powered from batteries the following warnings are displayed when the batteries are low When the batteries are running low a warning message will be shown You should now connect the power supply or USB cable as soon as possible When the batteries are too...

Page 72: ...it comes over and over you may need to increase the trig level by raising the threshold see topic Settings This pause symbol indicates that hold has been activated during measurement on fluoroscopy This symbol indicates that there are more items not visible in a list Tap the symbol or press the up down buttons to view not visible items This symbol is similar to the previous Tap to move the cursor ...

Page 73: ...gs Waveform indication This symbol indicates that the waveform was set or determined as DC HF Tube voltage readings are affected by this The waveform functionality can be changed under Settings Waveform indication This symbol indicates that the waveform was set or determined as single phase Tube voltage readings are affected by this The waveform functionality can be changed under Settings Waveform...

Page 74: ...u install the QABrowser For the RTI Handheld Display or Palm OS handheld computer see the HTML help file on your Product CD for details 3 10 1 Updating QABrowser on the handheld The QABrowser Updater helps you to install update the QABrowser software on the handheld computer To update install the QABrowser 1 First install the QABrowser Setup as described in the previous chapter 2 In the end of the...

Page 75: ...our handheld computer This process may take several minutes When the HotSync Progress window disappears all files have been transferred to the handheld computer At the same time a complete backup of your handheld has been done and saved on the PC 10 You can now remove the handheld computer from the cradle You may be asked to make a Reset of the handheld computer Do that by tapping the Reset button...

Page 76: ...mpletely 1 Remove the QABrowser on you handheld device 2 Uninstall the QABrowser Updater on your PC Removing the QABrowser from your handheld Simply remove by deleting the icon on the Palm You find a Delete menu in the Application Launcher Removing the QABrowser Updater from your PC This is accomplished by using the Windows Control Panel Add and Remove Programs or by choosing Start RTI Electronics...

Page 77: ...Measurement Principles Theory Chapter 4 ...

Page 78: ...OK OK Mammography OK OK CT OK OK Dental OK OK OK Panoramic Dental OPG OK OK OK Measurement Type Settings 4 2 For both the QABrowser and Ocean a number of measuring settings and update modes can be selected some of them also determines active sensitivity range the selected integration time etc and also controls the way the displays and or electrometers are reset The table below shows the default se...

Page 79: ...any trig levels or background compensation When the time has passed a reading will be presented It has a long reset time for increased accuracy which varies with the sensitivity as seen in the table below Free run the Piranha will continuously measure the radiation without any trig levels or background compensations No applications are available when using this mode The mode has a feature called m...

Page 80: ...et means that a reset is performed after each trig off Reset time is the time it takes to perform a reset each time you hit Reset Sample time is the time between individual data point of the waveform Waveform recording time is the range of user selectable recording times the Piranha allows Note that in Timed and Free run you may get negative readings for instance if you press reset when a signal i...

Page 81: ... make sure not to do a Reset between these measurements as the Reset will also make an offset adjustment Note also that low level readings may give inaccurate kV readings For long duration measurements cases with slowly rising and falling output or cases with very low pulse rate timed mode may also be useful For instance on CT machines where the rotation cannot be stopped 4 3 2 Using Free Run Upda...

Page 82: ...ges 4 4 Even though the range of the Piranha measurement system is quite wide sometimes the signal may get too low or too high To inform you of this there are display messages These are mainly of two types Active or Passive Active messages are shown when the hardware settings can be adjusted to adapt the measurement ranges The active message will just inform you that it is making an automatic adju...

Page 83: ...erence Manual High signal One or several detectors have too high signal Low signal The Piranha detects a signal but it is too low to present a reliable result High kVp Measured tube voltage is higher than that of the selected kV range Low kVp Measured tube voltage is lower than that of the selected kV range ...

Page 84: ...The exposure time is too short compared to the delay time Increase the exposure time and or reduce the values of delay and or window time Keep in mind that the type of measurement sets the delay time value The standard value for radiography use is 5 ms but for dental it is 200 ms See Measurement Type Settings High kVp Measured tube voltage is higher than that of the selected kV range Change to a h...

Page 85: ... D2 and D1 is not within 5 quota not between 0 95 to 1 05 The most common reason for this is that the detector area is only partially irradiated the detector is tilted or the filtration differs between D2 and D1 e g heel effect Change the field size or move the detector into the central beam Negative Signal The electrometer module detects a negative signal Most common is that the mAs probe have be...

Page 86: ...ation ends i e it goes under the detector s lowest trig level 8 If the signal has been below the trig level during all of Post delay the exposure is considered finished All exposure readings are calculated Integrated signal dose mAs etc Is the integration of all signal which means the area below the curve above from point 1 to 7 During the measurement exposure the accumulated signal dose etc is di...

Page 87: ...have different thicknesses all optimized for different ranges of the tube voltage two 1 and 2 are used for the low mammography energy range 20 to 45 kV and three filters 3 5 are used for the radiography range 35 to 155 kV 35 75 55 105 and 80 155 kV Using these four signals S1 S4 from detectors D1 to D4 the Piranha can accurately calculate the corresponding tube voltage The signal S3 is not affecte...

Page 88: ...al filtration with one exposure optimally there are some settings to be aware of Since the highest accuracy is obtained between 60 and 120 kV we recommend to do the measurement of the total filtration in between at 80 kV The Piranha is also calibrated for the total filtration at this kV Use a high signal level i e 200 mA during 200 ms to get a stable result It does not matter if you intend to do m...

Page 89: ... the table top If patient equivalent phantom should be used it is recommend to use the Piranha HVL stand to simplify the set up Use 2 pieces of 10 mm Al filter as patient equivalent filter in the beam 2 Set the X ray generator to technique factors commonly used clinically 3 If the display is unstable press the Reset button 4 Use some form to record your measurements 5 Make exposures at different m...

Page 90: ...he output reproducibility 1 Place the dose detector on the table top the patient equivalent phantom is not necessary since this measurement can be made as a relative measurement 2 Set the X ray generator to technique factors commonly used clinically 3 If the display is unstable press the Reset button 4 Use some form to record your measurements 5 Make 5 to 10 exposures and record the reading for ea...

Page 91: ...Measurements with the Piranha System Chapter 5 ...

Page 92: ...ending on model measure up to eight parameters simultaneously plus three waveforms from a single exposure kVp Dose and dose rate Exposure time HVL Estimated total filtration and determined waveform type mAs and mA pulses kV waveform Dose rate waveform mA waveform various pulsed fluoroscopy parameters Using the Piranha alone 6 parameters and two waveforms can be measured simultaneously ...

Page 93: ... It also has a very wide dynamic range so it very rarely happens that the signal level is not enough to get a correct kVp value The radiography kV range is 35 to 155 kV You can either select the tube voltage as single parameter or together with dose dose rate and exposure time As complementary information estimations of the total filtration and type of waveform are made This feature uses the kV fi...

Page 94: ...lses You can also change the dose and dose rate units Tap the dark part of the display where the unit and its prefix are displayed to get the list of units or for the supplementary data at the bottom you tap the unit The value for the new unit is automatically calculated and displayed A delay of 5 ms is standard but can be changed when necessary It is important to select an exposure time longer th...

Page 95: ...ues and can be displayed by tapping Wave Applications and logging of the real time values are described earlier 5 2 1 kVp Time Dose and Dose Rate To measure on radiographic units 1 Set up the Piranha and the handheld computer according to the description in Setting Up the Piranha 2 Place the detector on the table at the distance that is clinically relevant Place the Piranha in the direction indica...

Page 96: ...ated The Piranha automatically changes back to the previous selected kV range As default this is radiography range R2 indicated by a 4 on the QABrowser screen 6 Set kVp and mAs or mA time to the desired values 7 Make an exposure The RTI logo flashes to indicate that the Piranha has detected the exposure The Piranha now first analyses the beam and displays the type of waveform This is done once for...

Page 97: ...timated in the range of 50 150 kV Depending of the selection of display parameter different display screens may be presented 8 Tap Wave to study the waveforms 9 You can use the pen to move the cursor 10 Tap Back to return to the real time display 11 Repeat the measurement for other generator settings or select an Application tap Appl to measure further ...

Page 98: ...Up the Piranha 3 Follow the same steps as for the measurement with Piranha but select Dose as parameter and then External 3 Set kVp and mAs or mA time to the desired values 4 Make an exposure The RTI logo flashes to indicate that the Piranha has detected the exposure 5 Read the values As complementary information the dose rate and exposure time is also displayed below Tap Wave to view the correspo...

Page 99: ... section HVL Total Filtration Using the Piranha and the built in HVL application correct HVL value and total filtration value can be measured and calculated Set up the system the same way as described earlier to measure dose in radiography beams and select the Piranha The only difference is that you select the built in HVL application for the dose measurement The HVL application can be found in th...

Page 100: ...iew a graphical presentation of the result It is recommended to use the built in HVL application or Ocean to evaluate HVL 5 2 3 1 Introduction 2 The Piranha system can depending on model measure up to eight parameters simultaneously plus three waveforms from a single exposure kVp Dose and dose rate Exposure time mAs and mA Estimated total filtration and determined waveform type kV waveform Dose ra...

Page 101: ...r on the table at the distance that is clinically relevant Place the Piranha in the direction indicated in the figure below Adjust the collimator so the radiation clearly covers the detector rectangle marked on the Piranha top panel but try to keep the field size inside the top panel size to minimize scatter Recommended field size is 20 40 mm Furthermore the Piranhasurface should optimally be plac...

Page 102: ... this is radiography range R2 indicated by a 4 on the QABrowser screen 6 Set kVp and mAs or mA time to the desired values 7 Make an exposure The RTI logo flashes to indicate that the Piranha has detected the exposure The Piranha now first analyses the beam and displays the type of waveform This is done once for every test Then the estimated total filtration is displayed estimated in the range of 5...

Page 103: ...ribed earlier in this manual The total inaccuracy is about 0 3 mm in the range of 2 to 10 mm and 10 in the range 10 to 25 mm see Specifications Piranha The purpose of this value is to always be able to calculate correct kVp and dose value independent of beam filtration But it can also be used as a quick way to estimate the filtration and alert you if the filtration has changed since last measureme...

Page 104: ... be determined at three different kV settings with only three exposures With the initial exposure the total filtration is displayed 6 8 mm Al before the kVp is displayed Then the measured kVp is shown 117 0 kV and the estimated total filtration and HVL are shown as supplementary information The HVL is calculated to be 6 42 mm Al The set kV was changed and the Piranha measured 102 6 kV The HVL is c...

Page 105: ...t is much lower Therefore depending on type of acquisition mode it may be better to select the pulsed fluoroscopy measurement type for the Piranha Please consult the next section of the manual if this is the case For under table cine measurement turn the Piranha upside down An optional detector rod is available that can be used to put the detector in position on the image intensifier without risk ...

Page 106: ...or the normal radiography measurement but select the All parameter If only Tube voltage is selected 5 3 2 Pulse Measurements with Piranha Dose Probe Use the same procedure as for the normal radiography measurement Note that if it is difficult to get a good pulse rate reading you may use a manual pulse rate setting as described under Settings to get a dose per pulse reading 43 ...

Page 107: ...ranha upside down Use the optional detector rod to be able to put the detector in the cassette holder or on the image intensifier without risk of hazardous X ray The Position Check should be used to confirm the position of the Piranha When you select fluoroscopy or pulsed fluoroscopy as type of measurement the Piranha system automatically changes to continuously updating the display and using the ...

Page 108: ...e the average dose rate as total dose divided by the exposure time Note that for very low dose rate values the exposure time cannot be measured accurately and the last dose rate value cannot be stored automatically in the display Then tap Hold to freeze the current value in the display The waveform is also acquired when you tap Hold Waveform is also automatically acquired when the selected delay t...

Page 109: ...e optional detector rod that can be attached to Piranha Dose Probe to position the detector without risk for hazardous X ray exposure Observe the image on the monitor 8 The real time display is now displayed Set the generator Tap Reset Since the external dose probe Piranha Dose Probe is not sensitive to back scatter a lower value compared to a transmission ion chamber is typically detected typical...

Page 110: ...luoroscopy 13 Read the values 5 4 2 kVp and Dose Rate Use the same procedure as for the image intensifier input dose rate measurement but select All parameters instead 1 The first screen shows how the continuous updated display looks like The little black arrow indicates that the radiation is detected and the display is updating every four seconds 2 The second screen shows that the Piranha has det...

Page 111: ... 5 The last screen above shows actually the same measurement with added 10 mm filter to reduce the dose rate even further Note that the kV value is the same since the Piranha even on this extremely low level still makes corrections for the beam filtration The Piranha can measure both kV and dose rate at very low levels for instance on Mini C arm systems Piranha can as an example successfully measu...

Page 112: ... Select Dose rate 2 Tap Appl and select HVL 3 Use the Hold button to store a reading and move to next line when the displayed value is stable Total Filtration and Quick HVL The total filtration is measured continuously when the Piranha is used under fluoroscopy The following pictures illustrates this excellent feature for the Piranha and the Internal detector shown for Barracuda MPD The fluoro is ...

Page 113: ...otice that the filtration is changed and shows a new total filtration value The dose rate is now much lower The added filtration does not affect measured kVp at all Note how the Piranha directly responds to a sudden change of the filtration The display is continuously updated with the kV time and dose rate The dose rate value decreases when the extra 10 mm Al is put in the beam but the continuousl...

Page 114: ...p 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 pu...

Page 115: ...stem is used this type of measurement These pictures describes the check of the output levels in pulse fluoroscopy mode showing Barracuda MPD This example shows measurements of dose pulse dose rate and pulse rate on an ordinary C arm system Example of more measurement done using this application The first slides are the measuring results of measuring on a 5 Hz fluoroscopy system ...

Page 116: ...he noise level is too high to detect the pulses in the signal The pulsed fluoro mode works also well on X ray generators that only have a continuous fluoro output The Dose pulse screen has been configured to always display the Dose rate and Pulse dose rate continuously during the measurement period even when pulse information is lacking Be aware of that during the fluoro the continuous dose rate v...

Page 117: ...at Mo 2 mm Al M2 Rh 1 mm Al M5 supports only kVp measurement no dose measurement with Piranha is possible Mo 2 mm Al is not used that often but the GE DMR unit use Mo 1 mm Al so simply add one extra 1 mm Al in the beam when measuring kVp This since the kV of the generator is the same regardless of the filtration You can either select the Tube Voltage as single parameter mode or All and get kVp tog...

Page 118: ... and radiation waveform is always stored together with the RTD values and can be displayed by tapping the Wave button The kVp calibration for Piranha is made without the compression paddle in place The purpose of dose measurement is often to determine the ESAK Entrance Surface Air Kerma or ESE Entrance Skin Exposure It is recommended to perform dose measurements according to a mammography protocol...

Page 119: ... the USB port points in the patients left direction as shown in picture To be able to get comparable results please consider the position of the Piranha The Piranha should be placed at a clinically relevant distance from the chest wall Recommendations for this varies typically between 40 and 60 mm For Europe 60 mm is the recommended distance Ref ECR 16263 EU 4 Connect the devices Handheld For Blue...

Page 120: ...t you use the correct settings see section Corrections for the Compression Paddle 2 Select the correct radiation beam quality The radiation quality is shown in the lower right corner 3 Make a Position Check as shown above It is recommended to make the check at 28 kV After the check the Piranha automatically changes back to the previously selected kV range 4 Set kVp and mAs or mA time to the desire...

Page 121: ...nstance The Hologic Selenia and IMS Giotto In those cases RTI have updated Application Notes and there may be some even for other units Please check the RTI Electronics website www rti se for the latest info For Sectra MDM Fischer Senoscan and other scanning beam units please see the section Scanning Beam Mammography 5 5 4 Dose Measurements with the Piranha Dose Probe It is often more convenient t...

Page 122: ...TECTOR DATA manual You may store the correction as a Beam Correction Factor in a Favourite for a specific kV to do the correction automatically 8 Repeat the measurement for other generator settings To get a good HVL value using the Piranha Dose Probe you must correct it according to the tables in the Piranha Dose Probe DETECTOR DATA manual It is often more convenient to measure HVL with the Piranh...

Page 123: ...value has been reduced to less than half the HVL is calculated and the graph can be selected 5 5 6 Quick HVL Quick HVL The Piranha is able to measure HVL for mammography in one shot Quick HVL is available for measurements with or without compression paddle If the parameter All w HVL is chosen the QABrowser will display quick HVL values for every measurement 5 5 7 Mammo Compensations and Correction...

Page 124: ...t compression paddle is used That is equal to approximately 3 mm of plexiglass PMMA For W Al beam energy an equivalent compression paddle of 0 18 mm Al is typically used instead If you tap the symbol you can see these two settings under Conditions When comparing with typical mammographic ion chambers listed above you should multiply the Piranha dose value with a scatter factor of 1 06 to make it m...

Page 125: ...the wanted measuring position is then 605 mm 3 When the normalizing function is used it is indicated with a blue N as indicated in the last figure The dose and dose rate values are then normalized to this virtual position at 605 mm SDD A practical consequence of usage of the normalizing function and scatter factor is that the Piranha can be kept at the same position on the breast support all the t...

Page 126: ...angular corrections field inhomogeneity corrections etc If you save this setting as a Favourite you can have a quick way of repeatedly making a special measurement without any manual corrections 5 5 7 4 Corrections for Angular Sensitivity For mammography the following correction table may be used at a SDD of 60 cm if the Piranha is placed flat on the breast support This assuming that the focal poi...

Page 127: ...indicated with a red icon Important quantities to measure The most common measurements for a mammographic system are conducted to determine the average glandular dose AGD The AGD values are based on measurements of ESAK entrance surface air kerma and HVL To do the measurements correctly and according to standards the radiation detectors should be placed directly below the compression paddle This i...

Page 128: ...ely To collect data from real exposure set the delay not the post delay to exclude the pre pulse When the data has been acquired change the radiation quality to the one chosen by the system and the measured data is automatically corrected For the time being this feature is only present in the QABrowser software With Ocean a new exposure has to be made with the correct radiation quality using the s...

Page 129: ...hat the output level is much lower and the total filtration is normally around 2 mm Al The setup is straightforward and also to get the measured value Most dental units is still single phase self rectified and has 100 radiation and kV ripple In the case of one phase dental units it is common that only the exposure time can be changed In most cases the set tube voltage and current is fixed to about...

Page 130: ...xposure time The dose value is collected for the whole exposure time If you need to change the sensitivity delay or and measuring window tap to show the settings and make your choices In the case of dental panoramic system the situation is somewhat different Here the kV and radiation waveform often is very well regulated The challenges instead arise for the mechanical setup needed to position the ...

Page 131: ...er use different mA or scan speeds when the scanning beam passes the neck region Newer digital system can actually measure patients X ray beam attenuation dynamically and change the output level automatically during the scan The Piranha has addressed these challenges Since the panoramic scan has an exposure time of about 10 to 20 seconds the Piranha is set up to continuously update the display dur...

Page 132: ...isplayed dose value has very little energy dependence since it is automatically compensated for each exposure since the kV estimated filtration and the waveform are measured 5 6 1 kVp Time Dose and Dose Rate Use the same procedure as for the normal radiography measurement but select Dental instead of radiography and select Tube voltage as parameter A 200 ms delay is default 1 Set up the Piranha an...

Page 133: ...cular to the focal spot see also Angular Sensitivity Piranha 3 It is recommended to make a check measurement to confirm that the detector area is uniformed radiated Select a exposure time of at least 400 ms The Piranha automatically changes back to the previous selected kV filter after the check exposure As default this is radiography filter R2 indicated by a 4 on the QABrowser screen 4 Set the kV...

Page 134: ... on a one phase dental unit Delay 0 ms Delay 200 ms Delay 500 ms From the study of the above three screens several conclusions can be made 1 A stable output level is not reached until after approximately 200 to 300 ms 20 to 30 pulses for a 50 Hz main based dental unit 2 The exposure time is depending on the definition of the trig level 3 The kVp value in the RTD is related to selected delay and wi...

Page 135: ...t up the Piranha and the handheld computer according to the description in Setting Up the Piranha Selecting one parameter mode enables you to see the measured values from a distance of several meters 2 Mount the Piranha and power on the Piranha 3 The real time display for Tube voltage is now displayed 4 It is strongly advised to make Position Check to confirm that the detector area is uniformed ir...

Page 136: ...ilm image below shows that in the bottom part of the image you can see a part of X ray slit image In this case the radiation beam centre is about 4 mm from the centre line indicated by the thin centre black line Move the detector about 4 mm to get it in the beam was the cure for this case to be able to pass check measurement criteria 6 Press the rewind button on the panoramic unit to take back the...

Page 137: ...on is measured as well as the scan time The figure shows the RTD after a complete scan The waveform is also automatically stored after the delay time in the beginning of the scan or acquired when Hold is activated during the scan 5 6 4 HVL Total Filtration and Quick HVL It is not unusual that the total filtration is as low as 2 0 mm Al on an dental unit compared to 2 5 to 3 5 mm on an normal radio...

Page 138: ...ogram scout pilot image is taken A topogram is obtained with a moving table and a stationary tube normally in the top position The topogram is normally used to provide information for the actual CT scan It is recommended to use a slice width of 3 mm or wider That is if selectable use as large slice width as possible You may also want to use the Timed mode to allow measurements on moving CT machine...

Page 139: ...ons are available C1 W 3 0 mm Al C2 W 3 0 mm Al 0 25 mm Cu optional C3 W 3 0 mm Al 1 2 mm Ti optional In earlier software versions the Piranha could not measure total filtration in the CT application Therefore an extra radiation quality C2 corresponding to measurements inside a phantom was necessary in order to get a correct kV Now this is taken care of automatically since the total filtration is ...

Page 140: ...he position is accepted and the real time display is shown again If not check the position of the Piranha and or increase the slice width if possible 9 You are now ready to measure Repeat the topogram program to measure kVp The exposure time you measure is not related to the actual radiation time It is the time it takes for the detector to pass through the CT X ray field when the table moves when ...

Page 141: ...existing scanner models and can be of assistance to make correct settings References 1 Nagel H D Radiation Exposure in Computed Tomography Fundamentals Influencing parameters Dose Assessment Optimisation Scanner Data Terminology 4th Edition Hamburg Germany December 2002 CTB Publications D 21073 Hamburg ctb publications gmx de 2 Stamm G Nagel H D Software CT Expo Medizinische Hockschule Hannover D ...

Page 142: ...sure only the mAs that actually contributes to the exposure and the generation of the image The discussion above is generally true for the invasive MAS 1 probe since it is connected in the transformer and measures all current The non invasive probes MAS 2 and MAS 3 can be placed anywhere on the HV cable If they are placed close to the tube they will measure only the current that floats through the...

Page 143: ...esult from an exposure with 80 kV 50 ms and 100 mA The exposure time is measured with the external probe input If you would get a message as shown in the figure to the left the current is floating in the wrong direction in the mAs probe Switch the two connectors that are connected in the mAs measuring socket tap Reset and make a new exposure Since the MAS 1 probe is connected in the X ray generato...

Page 144: ...earlier in this manual 2 Connect the MAS 1 probe to the X ray generator as described in the MAS 1 User s Manual 3 Connect the MAS 1 probe to the external probe input 4 In the QABrowser select type of measurement 5 Select Tube Current from the menu 6 The real time display for tube current is now displayed Set the generator Do a Reset 7 Start the fluoroscopy 8 The figure to the left shows the real t...

Page 145: ...th MAS 2 is 10 mA The figure to the left shows the MAS 2 probe without the cable The parameter mAs is available for most type of measurements but mAs is normally measured only for X ray exposures To measure tube charge mAs with the Piranha MAS 2 Probe 1 Connect the MAS 2 probe to the X ray generator Then power on the MAS 2 by turning the range switch to the 4 A range and make a Reset of the MAS 2 ...

Page 146: ... probe tap Reset and make a new exposure Since the MAS 2 probe is based on measurement of magnetic flux false triggering may occur due to electrical noise when the pre heat is started and the anode starts to rotate If you get incorrect or inconsistent results try the following First start anode rotation without firing the exposure While the anode is rotating tap Reset or press corresponding button...

Page 147: ...nance cd m measurements on CRTs monitors and viewing boxes and illuminance lx measurements of ambient light in a room or in front of a CRT Read the Piranha Light Probe User s Manual for a detailed description of practical use and explanation of the theory behind the units and quantities of light The monitor adapter is shown to the left and the lux adapter to the right 5 9 1 Luminance Monitor Viewb...

Page 148: ...e display You can now move the Piranha Light Probe to other points and measure the light If you are measuring very low light intensities it may occur that the Piranha does not start to measure You should then do as follows 1 Do as described in step 1 to 8 above 2 Press and hold the shutter If the Piranha does not start to measure lift the Piranha Light Probe and direct it towards a bright spot wit...

Page 149: ...anha Light Probe L probe 7 Tap Select 8 The real time display for illuminance is now displayed Cover the white light sensitive area of the Piranha Light Probe to shield off all light you may use the rubber part that comes with the Piranha Light Probe M if available It is very important that you shield off all light Then tap Reset After that you can remove the shield and place the light detector wh...

Page 150: ...5 Measurements with the Piranha System Light Measurement Piranha QABrowser Reference Manual 2014 06 5 5C 146 4 Read the result on the display ...

Page 151: ...Optional Accessories Chapter 6 ...

Page 152: ...lows you to position the Piranha or the Piranha Dose Probe and HVL filters in any angle including upside down Use the light field or other help to position the Piranha in the X ray field The Piranha detector is not sensitive for different field sizes as long as the entire sensitive detector area is irradiated but try to keep the field size down to minimize scattering Recommended field size for Pir...

Page 153: ...the left to position it right on the slot 3 Fixate the Holder using the magnets or if no magnets are allowed adhesive tape to the surface 4 Adjust the position in detail using the set screws 5 If needed use the bendable plate to fit it around a corner as shown below Magnet or tape position Bend the included plate here Fasten the included plate with the base with this screw Magnet or tape position ...

Page 154: ...6 Optional Accessories Piranha Panoramic Holder Piranha QABrowser Reference Manual 2014 06 5 5C 150 ...

Page 155: ...Problems and Solutions Chapter 7 ...

Page 156: ...rous trig indications If you get the trig indicator play symbol when there is no signal 1 Press reset 2 If it comes over and over you may need to increase the trig level by raising the threshold see topic Settings The electrometer or Piranha gives too low dose rate If you get to low dose rate readings or too short irradiation times for short exposures 1 Check that you are measuring with a good geo...

Page 157: ...nable to reconnect using Retry Tap Exit and restart the Piranha and then re start the QABrowser again Bluetooth only shows Unknown device when trying to connect Depending on Palm model it may take a little while for the serial number to appear the Piranha will appear as Unknown device Normally it will show the serial number if you wait a while How do I change from Gray to Röntgen units You can set...

Page 158: ...ith your PC and meter then this is recommended 7 2 1 Bluetooth Passkey There are two different ways to use Bluetooth with you meter without a passkey and with a passkey also called PIN code authentication and Bluetooth security code All meters and accessories that are delivered from RTI Electronics from the first quarter of 2010 are configured to use a passkey 0000 Drawbacks of using a Passkey If ...

Page 159: ...will have a key next to it and it will work properly 3 Quit the QABrowser by for instance a soft reset and add the meter as a trusted device It is recommended that you do this before you launch the QABrowser after having used the meter with Bluetooth and another device handheld PC Add as a Trusted Device on Palm OS If you have not yet launched the QABrowser you can do the following 1 Launch Prefs ...

Page 160: ...able Bluetooth Passkey If you experience problems with this then you probably need to update you meter firmware before you can enable the Bluetooth passkey Please run the available updates by pressing Start and then restart the application again to enable the Bluetooth passkey 8 Follow the onscreen instructions If you want to disable the Bluetooth passkey do the same thing but select Disable Bluet...

Page 161: ...Glossary Chapter 8 ...

Page 162: ...n a given quantity of radioactive material per unit time The SI unit of activity is s 1 The special name for the unit of activity is becquerel Bq The previously used special unit of activity was the curie Ci 1 Bq 2 7 x 1010 Ci 1 Ci 3 7 x 1010 Bq See Report No 82 NCRP 1985b SI unit Bq s 1 Additional filtration ADDED FILTERS and other removable materials in the RADIATION BEAM which are between the R...

Page 163: ...ch normally just starts the Firmware It is used more when the Firmware is updated See Firmware Centigray 0 01 gray 1 cGy equals one rad Cinefluorography The production of motion picture photographic records of the image formed on the output phosphor of an image intensifier by the action of X rays transmitted through the patient often called cineradiography Cineradiography Indirect radiography of m...

Page 164: ...technique factors See definition Digital radiography A diagnostic procedure using an appropriate radiation source and an imaging system which collects processes stores recalls and presents image information in a digital rather than analogue fashion Digital subtraction An image processing procedure used to improve image contrast by subtracting one digitized image from another Dose equivalent H A qu...

Page 165: ...e filter permanently in the useful beam it includes the window of the X ray tube and any permanent enclosure for the tube or source Replaced by term Permanent filter Filter Added filter Filter in addition to the inherent filtration Filter Permanent filter The filter permanently in the useful beam it includes the window of the X ray tube and any permanent enclosure for the tube or source Filter Tot...

Page 166: ...et surface must pass through more target material before escaping from the target than does the major portion of the beam which is emitted more perpendicularly Note In addition to the non uniform intensity the angled target also produces non uniform image resolution due to variations in apparent focal spot size as viewed from various positions on the film Hounsfield units See CT number Image inten...

Page 167: ...onization in the sensitive volume of the detector Irradiation time Irradiation time is usually the time a rate of a RADIATION QUANTITY exceeds a specified level Irradiation time is sometimes called Exposure time SI unit s second Kerma K The sum of the initial kinetic energies of all the charged ionizing particles liberated by uncharged ionizing particles per unit mass of a specified material Kerma...

Page 168: ...MTF can be thought of as a measure of spatial resolution of the detector system SI unit m 1 Monitor personnel See personnel monitor Occupancy factor T The factor by which the workload should be multiplied to correct for the degree of occupancy by any one person of the area in question while the source is in the ON condition and emitting radiation This multiplication is carried out for radiation pr...

Page 169: ...AL PEAK VOLTAGE Primary protective barrier See protective barrier Protective apron An apron made of radiation absorbing materials used to reduce radiation exposure Protective barrier A barrier of radiation absorbing material s used to reduce radiation exposure Protective glove A glove made of radiation absorbing materials used to reduce radiation exposure Rad The previously used special unit of ab...

Page 170: ... subject contrast levels and noise of the overall imaging system Roentgen R or Röntgen The previously used special unit of exposure 1 R 2 58 10 4 C kg Originally Stockholm 1928 defined as international R Symbol r and later Chicago 1937 modified to Roentgen or ray that gives a charge of 1 esE from secondary emission in 0 001293 g of air This means that an exposure of one Roentgen will produce 2 58 ...

Page 171: ...nce 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 o...

Page 172: ...ng imaged The mean attenuation coefficient of the voxel determines the CT Hounsfield number of the pixel Whole body dose equivalent Hwb The dose equivalent associated with the uniform irradiation of the whole body Workload W The degree of use of a radiation source For X ray machines operating at tube potentials below 500 kV the workload is usually expressed in milliampere minutes per week For gamm...

Page 173: ...ions 52 Multi parameter 55 Single parameter 53 Authentication Bluetooth 154 Auto prompt 65 Auto reset 74 75 Automatic exposure control 158 Auto power off 152 Autoscaling 152 Average Glandular Dose 117 123 B Battery charging 67 charging times 13 indicator 67 level 10 13 67 running time 10 13 status 10 67 warning 67 Battery charging indicator 10 Beam Correction 69 Beam Correction Factor 48 122 Beam ...

Page 174: ...Default settings 74 Default Unit 152 Delay 50 52 74 82 130 Start efter 48 Waveform 48 Delay time 80 Deleting a Favourite 60 Demo 37 Dental 125 Default settings 74 HVL 133 Quick HVL 133 Total filtration 133 Dental panoramic 131 Dental panoramic radiographic 160 Dental specifications 16 Dental waveforms 130 Detector 38 Detector area 14 Detector Information 66 Detector Manager 35 Detector settings 52...

Page 175: ...5 77 Free run update mode 48 Using 77 G Gantry 162 Geometric unsharpness 162 Good geometry HVL 120 Gray Gy 162 H Half Value Layer Theory 83 Half value layer HVL 162 Handheld Reset 152 Heel effect 12 162 Help 89 High kVp 78 80 High signal 78 80 Hold indicator 68 Holder 148 Piranha 12 HotSync 37 57 70 152 Hounsfield units 162 House Icon 68 How To Report a Problem 156 HVL 83 95 Application 95 Cine 10...

Page 176: ...As 138 141 MAS 1 Probe Specifications 28 MAS 2 Current Probe 141 MAS 2 Probe Specifications 28 Mean Glandular Dose 117 123 Measured value 164 Measurement 101 110 Cine 101 Dental 128 Dose 94 Dose per pulse 101 110 Fluoroscopy 103 Image intensifier 104 Mammography 115 Number of pulses 101 Panoramic dental 131 Pulse rate 110 Pulsed fluoroscopy 110 Pulsed radiography 101 Radiography 89 91 97 Measureme...

Page 177: ...ay 48 74 82 Power Management 67 Power supply 67 Power switch 9 PPV 38 PPV waveform 42 Practical Peak Voltage 38 Practical Peak Voltage PPV 164 Preferences 65 Prefixes Lock 65 Prefixes Unit 152 Pre pulse mammography 124 Primary protective barrier 164 Probes Managing 35 Viewing 35 Problem Report 152 156 Protective apron 164 Protective barrier 164 Protective glove 164 Pulse Measurements 102 Pulse Rat...

Page 178: ...50 52 Threshold 50 52 Total Filtration 45 Trig level time 48 Trig source 48 Update mode 48 Waveform recording time 48 Waveform type 45 Window 50 52 Setup Log 65 Power Management 67 Preferences 65 QABrowser 63 Regulations 64 System Info 66 System Test 66 Units 64 Shutter 166 Sievert Sv 166 Signal Extension Module 88 96 Signal to noise ratio 166 Simulator 166 Size 15 Sleep time 65 Slice 166 Source 1...

Page 179: ... CT 137 Dental 133 Fluoroscopy 108 Radiography 99 Trig Visual indication 65 Trig indicator 68 Trig level time 48 Trig source 48 Trigger 82 Troubleshooting 152 Trusted device Bluetooth 155 Tube current Invasive 138 Non invasive 141 Tube current measurements 137 Typical CTDI values 136 Typical Response 21 Typographical Rules 5 U Uninstallation QABrowser 72 Unit Default 152 Gray 152 Prefixes 152 Rönt...

Page 180: ...Piranha QABrowser Reference Manual 2014 06 5 5C Index 176 Weight 15 White screen 152 Whole body dose equivalent Hwb 168 Window 50 52 82 Window time 80 Workload W 168 X Xeroradiography 168 X ray tube 168 ...

Page 181: ...Notes Piranha QABrowser Reference Manual 2014 06 5 5C Notes 177 ...

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