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KaVo ProXam Extraoral systems
Instructions for use
Constancy test DIN 6868-5
EN
The manufacturer, assembler and importer are responsible for the safety, reliability and
performance of the unit only if:
- installation, calibration, modification and repairs are carried out by qualified
authorised personnel
- electrical installations are carried out according to the appropriate requirements such
as IEC 60364
- equipment is used according to the operating instructions.
Planmeca pursues a policy of continual product development. Although every effort
is made to produce up-to-date product documentation this publication should not be
regarded as an infallible guide to current specifications. We reserve the right to make
changes without prior notice.
COPYRIGHT PLANMECA
Publication Number 1.015.1559 Revision 1
Release Date 1 March 2023
Table of contents
1 Introduction.................................................................................................................................................1
2 Constancy test tools................................................................................................................................... 2
3 Preparing Romexis..................................................................................................................................... 3
4 Constancy test for panoramic imaging....................................................................................................... 4
4.1 Positioning test phantom................................................................................................................ 4
4.2 Positioning copper plate assembly and copper filter...................................................................... 5
4.3 Adjusting X-ray unit........................................................................................................................ 6
4.4 Taking test exposure...................................................................................................................... 6
4.5 Evaluating test results.................................................................................................................... 7
5 Constancy test for cephalometric imaging................................................................................................10
5.1 Positioning test phantom.............................................................................................................. 10
5.2 Positioning copper plate assembly...............................................................................................12
5.3 Cephalometric X-ray unit settings.................................................................................................13
5.4 Preparing test exposure............................................................................................................... 13
5.5 Evaluating test results.................................................................................................................. 14
Instructions for use Extraoral constancy test DIN 6868-5
Table of contents
Extraoral constancy test DIN 6868-5 Instructions for use
1 Introduction
These instructions describe how the constancy test is performed in
accordance with DIN 6868 Part 5 on KaVo ProXam 2D and 3D X-ray units.
These instructions apply to the following X-ray units:
• KaVo ProXam 2D
• KaVo ProXam 3D
• KaVo ProXam 3DQ
with or without cephalostat.
NOTE
Read these instructions thoroughly before performing the constancy test.
X-ray images of a Quart test phantom are prepared for the constancy
test. According to the X-ray Ordinance (Röntgenverordnung), the constancy
test must be carried out by the operator once a month to confirm image
quality. The test results determine whether the image generation meets
the legal requirements, i.e. if the quality of the image generation has
remained constant within the defined thresholds within the framework of the
acceptance test. These thresholds are defined in the appropriate acceptance
test protocols supplied with the device. The service technician who installs
the X-ray equipment is responsible for carrying out and documenting the
acceptance test.
The constancy test is carried out according to DIN 6868-5 “Image quality
assurance in diagnostic X-ray departments - Part 5: RöV constancy testing
of dental radiographic equipment” and the test exposure must be evaluated
according to the criteria defined therein.
To compare the constancy test exposure with the acceptance test exposure
(reference exposure) it is very important that all settings used for the image
acquisition and image processing remain constant.
The dialogue windows shown in these instructions only serve as examples
unless otherwise specified.
NOTE
The digital X-ray units and the image processing program have separate
manuals that should be used with these instructions.
Original manufacturer
PLANMECA OY
Asentajankatu 6 FIN-00880
Helsinki FINLAND
Phone: +358-20-7795 500
Distribution
KaVo Dental GmbH
Bismarckring 39
88400 Biberach
Germany
Phone +49 7351 56-0
Fax +49 7351 56-1488
1 Introduction
Instructions for use Extraoral constancy test DIN 6868-5 1
2 Constancy test tools
2D Quart Test Phantom Set (2.023.4050) is required for the DIN 6868-5
constancy test for KaVo ProXam 2D, 3D and 3DQ X-ray units. The set is
optional and available as a spare part.
NOTE
Handle the test phantom with care and do not drop it.
1Test phantom
2Frame assembly
3Copper plate assembly
4Copper filter
5Phantom holder
6Cephalostat head support alignment plate
2 Constancy test tools
2 Extraoral constancy test DIN 6868-5 Instructions for use
3 Preparing Romexis
Steps
1. New patient is set up by a service technician.
Images are filed based on patient's name. The patient must therefore be
selected before the exposure.
The service technician sets up a corresponding “patient” in the Romexis
program so that test exposures can be prepared. The acceptance test
exposure (reference exposure) created by the service technician will be
filed under this “patient”.
2. Select this patient from the patient list.
For more information on Romexis, refer to
Romexis user's manual
.
3 Preparing Romexis
Instructions for use Extraoral constancy test DIN 6868-5 3
4 Constancy test for panoramic imaging
4.1 Positioning test phantom
Steps
1. Pull the ring of the locking pin (1).
At the same time, push the holder assembly in the designated slot
in the frame assembly (2). Release the locking pin when the holder
assembly is in place (3). The holder assembly is now secured in the
frame assembly.
2. Place the test phantom in the frame assembly.
Ensure that the side with the offset rings is facing forward. Position the
test phantom so that the groove is facing upwards.
1Groove
2Frame assembly
3Quart test phantom
4Offset rings
3. Remove the head support from the positioning table and, if necessary,
remove the chin support or the chin rest from the adapter.
4 Constancy test for panoramic imaging
4 Extraoral constancy test DIN 6868-5 Instructions for use
4. Fit the frame assembly into the adapter as illustrated.
The test phantom must be positioned so that the side with the offset
rings is facing forwards.
1Adapter
2Frame assembly
3Holder assembly
4.2 Positioning copper plate assembly and copper filter
Steps
1. Secure the copper plate assembly (L-shaped) to the X-ray unit housing.
NOTE
Ensure that the copper plate assembly is roughly in the middle of the
X-ray unit housing (as shown).
4 Constancy test for panoramic imaging
Instructions for use Extraoral constancy test DIN 6868-5 5
2. Then, as shown, position the copper filter onto the L-shaped copper
plate assembly you have just secured.
4.3 Adjusting X-ray unit
Use the exposure values (kV, mA) and device settings (program type,
patient size) set during the acceptance test.
The acceptance test is documented by the service technician and the
exposure values and device settings used in the acceptance test are
recorded in the form
Acceptance test for dental radiographic equipment
.
The exposure values are also entered in the form
Constancy test for
panoramic and teleradiographic systems in dental radiology
.
Precise instructions on the use of the X-ray equipment are set out in the
manual.
4.4 Taking test exposure
Steps
1. In the Romexis, right-click on the Patient for the test exposure from the
patient list.
2. Select Capture followed by Pan Exp.
3. When the system is ready to use, press the exposure button and hold it
down throughout the exposure.
Follow the instructions in the X-ray unit user's instructions.
4 Constancy test for panoramic imaging
6 Extraoral constancy test DIN 6868-5 Instructions for use
4. Click on the ready button at the bottom of the window of the Romexis to
accept the new exposure.
5. Select the Display properties option and name the exposure in the
Comments field.
This name differentiates the new test exposure from the other test
exposures to be performed later on. The information is stored with the
image and displayed as reference text.
6. Click Set Layout on the top toolbar.
7. Select the middle option.
If the test exposures are arranged next to each other on the screen, it
is easier to compare the new constancy exposures with the reference
exposure (taking the exposure test).
For more information on Romexis, refer to the
Romexis user's manual
.
NOTE
To compare the constancy test exposure with the acceptance test
exposure (reference exposure) it is very important that all settings used
for the image acquisition and image processing remain constant.
4.5 Evaluating test results
The test exposure must be compared with the X-rays taken during the
acceptance test and any deviations from the baseline must be checked.
The acceptance test was recorded by the service technician and the test
results are documented in the form
Acceptance test for dental radiographic
equipment
. These test results are treated as reference values for the
constancy test exposure that has now been created and are also entered
in the form
Constancy test for panoramic and teleradiographic systems in
dental radiology
.
The results of the constancy test exposure must be recorded separately. The
form
Constancy test for panoramic and teleradiographic systems in dental
radiology
is also used to record the test results of the constancy tests.
4 Constancy test for panoramic imaging
Instructions for use Extraoral constancy test DIN 6868-5 7
The results of the constancy tests must be entered in the table in the form
every month. The form has completed tables for the first year; after this,
you can attach a supplementary sheet with a corresponding table from your
X-ray unit book. Or alternatively you can simply copy the empty form if you
need to.
NOTE
Constancy test exposures and documents must be archived for two years.
NOTE
If there are any deviations from the baseline (reference exposure), it is
important that you immediately contact your service technician.
The constancy test exposure is to be evaluated in terms of the following.
1Minimum resolution: 2.5 Lp/mm
2Minimum contrast: 2 of the 4 elements
•Visual resolution capacity
The visual resolution capacity is tested with the aid of a lead line test
pattern. The monitor image of the panoramic test exposure must have a
minimum resolution of 2.5 line pairs/mm.
•Minimum contrast:
The minimum contrast is defined with the aid of low contrast elements
(drill holes). At least two of the four low contrast elements must be
detectable on the monitor screen of the panoramic test exposure.
•Area of effective radiation
4 Constancy test for panoramic imaging
8 Extraoral constancy test DIN 6868-5 Instructions for use
The constancy of the position of the area of effective radiation is shown
on the monitor image of the panoramic test exposure. At least one
unexposed edge (1) must be detectable on two opposite sides.
The imaging plate technology must have an unexposed edge all the way
round.
The following also applies to units with imaging plates.
•Uniformity of the procedure
The uniformity of the procedure is established based on the monitor
image of the panoramic test exposure. The horizontal stripes generated
by the image must be parallel. No radial run-out of the moving
mechanism may be evident.
4 Constancy test for panoramic imaging
Instructions for use Extraoral constancy test DIN 6868-5 9
5 Constancy test for cephalometric imaging
5.1 Positioning test phantom
Steps
1. Pull the ring of the locking pin (1).
At the same time, push the cephalostat head support alignment plate
(2) in the designated slot on the frame assembly as shown. Release
the locking pin when the cephalostat head support alignment plate is in
place (3). The positioning aid is now secured in the holder.
2. Place the test phantom in the frame assembly.
Position the test phantom as shown below.
1Test phantom
2Large slot
5 Constancy test for cephalometric imaging
10 Extraoral constancy test DIN 6868-5 Instructions for use
3. Turn the head support plate to the 0° position.
4. Open the release tabs and remove both ear posts and the nasal
positioner from the cephalometric X-ray unit.
5. Push the cephalostat head support alignment plate (1) into the mounting
part for the right ear post (on the sensor side) and close the release tab.
The test phantom must be positioned so that the side with the offset
rings is facing the sensor (3).
Ensure that the fixture is secure.
5 Constancy test for cephalometric imaging
Instructions for use Extraoral constancy test DIN 6868-5 11
1Cephalostat head support alignment plate
2Test phantom
3Sensor
4Cephalostat
5.2 Positioning copper plate assembly
Steps
1. Secure the copper plate assembly on the X-ray unit housing (if you have
not yet done this).
NOTE
Ensure that the copper plate assembly is roughly in the middle of the
X-ray unit housing (as shown).
NOTE
The copper filter is NOT used for cephalometric exposures.
5 Constancy test for cephalometric imaging
12 Extraoral constancy test DIN 6868-5 Instructions for use
5.3 Cephalometric X-ray unit settings
Use the exposure values (kV, mA) and device settings (program type,
patient size) set during the acceptance test.
The acceptance test is documented by the service technician and the
exposure values and device settings used in the acceptance test are
recorded in the form
Acceptance test for dental radiographic equipment
.
The exposure values are also entered in the form
Constancy test for
panoramic and teleradiographic systems in dental radiology
.
Precise instructions on the use of the X-ray equipment are set out in the
manual.
5.4 Preparing test exposure
Steps
1. In the Romexis, right-click on the Patient for the test exposure from the
patient list.
2. Select Capture followed by Ceph Exp.
3. When the system is ready to use, press the release button and hold it
down throughout the exposure.
Follow the instructions in the user's manual for the cephalometric unit.
4. Click on the ready button at the bottom of the window of the Romexis to
accept the new exposure.
5. Select the Display properties option and name the exposure in the
Comments field.
This name differentiates the new test exposure from the other test
exposures to be performed later on (e.g. constancy Pano June 2021).
The information is stored with the image and displayed as reference text.
6. Click Set Layout on the top toolbar.
5 Constancy test for cephalometric imaging
Instructions for use Extraoral constancy test DIN 6868-5 13
7. Select the middle option.
If the test exposures are arranged next to each other on the screen, it
is easier to compare the new constancy exposures with the reference
exposure (taking the exposure test).
For more information on Romexis, refer to the
Romexis user's manual
.
NOTE
To compare the constancy test exposure with the acceptance test
exposure (reference exposure) it is very important that all settings used
for the image acquisition and image processing remain constant.
5.5 Evaluating test results
The test exposure must be compared with the X-rays taken during the
acceptance test and any deviations from the baseline must be checked.
The acceptance test was recorded by the service technician and the test
results are documented in the form
Acceptance test for dental radiographic
equipment
. These test results are treated as reference values for the
constancy test exposure that has now been created and are also entered
in the form
Constancy test for panoramic and teleradiographic systems in
dental radiology
.
The test results of the constancy test exposure must be recorded separately.
The form
Constancy test for panoramic and teleradiographic systems in
dental radiology
is also used to record the test results of the constancy tests.
The results of the constancy tests must be entered in the table in the form
every month. The form has completed tables for the first year; after this,
you can attach a supplementary sheet with a corresponding table from your
X-ray unit book. Or alternatively you can simply copy the empty form if you
need to.
NOTE
Constancy test exposures and documents must be archived for two years.
NOTE
If there are any deviations from the baseline (reference exposure), it is
important that you immediately contact your service technician.
5 Constancy test for cephalometric imaging
14 Extraoral constancy test DIN 6868-5 Instructions for use
The constancy test exposure is to be evaluated in terms of the following
points.
1Minimum resolution: 2.5 Lp/mm
2Minimum contrast: 1 of the 4 elements
•Visual resolution capacity
The visual resolution capacity is tested with the aid of a lead line test
pattern. The monitor image of the cephalometric test exposure must
have a minimum resolution of 2.5 line pairs/mm.
•Minimum contrast
The minimum contrast is defined with the aid of low contrast elements
(drill holes). At least one of the four low contrast elements must be
detectable in the monitor image of the cephalometric test exposure.
•Area of effective radiation:
The constancy of the position of the area of effective radiation is shown
on the monitor image of the cephalometric test exposure. At least one
unexposed edge (1) must be detectable on two opposite sides.
For cephalometric X-ray systems with imaging plates, the edge
surrounding the three sides must be clearly shown if using soft tissue
filters.
5 Constancy test for cephalometric imaging
Instructions for use Extraoral constancy test DIN 6868-5 15
The following also applies to cephalometric X-ray systems with imaging
plates.
•Uniformity of the procedure
The uniformity of the procedure is established based on the monitor
image of the cephalometric test exposure. The horizontal stripes
generated by the image must be parallel. No radial run-out of the moving
mechanism may be evident.
5 Constancy test for cephalometric imaging
16 Extraoral constancy test DIN 6868-5 Instructions for use
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