Acquiring images using CMOS Sensors
Authored by:
Dr. Mindy Cash
Protocol for acquiring images in the
Radiology Clinic, using CMOS (complimentary metal
oxide semiconductor) sensors, including infection
control procedures
In the Radiology Clinic, the patient will
already be seated, the medical history reviewed
and a brief clinical exam performed, in order to
determine the required radiographic
prescription.
At dispensary:
- Once the prescription has been determined,
exchange tag(s) for the necessary equipment;
CMOS sensors in the required size(s) in
separate plastic containers, XCP positioning
devices. Bagged bitewing tabs are available in
the clinic operatories.
At the Imaging Chair:
Steps for acquiring images (prior to
gloving)
- Return to the operatory, where you will
find one white tray cover on the counter beside
the sink and a second tray cover on the counter
next to the computer.
- Place both containers, each containing a
CMOS sensor on the counter near the sink.
Remove the container lids and place under the
containers. Insert the CMOS sensor(s)
into their protective barrier(s), leaving the
outer wrapping on.
- If starting with the Size #1 sensor,
carefully remove the outer wrapping, ensuring
that the inner barrier is not touched with your
ungloved hands. Allow the barrier wrapped
sensor to be gently placed into the
container.
- Carry the container over to the
shelf/window and plug it into the USB hub.
- Open the bag containing the positioning
devices, and spill its contents onto the tray
cover beside the sink. Open the bag containing
the bitewing tabs and spill onto the same tray
cover (Donāt touch any of the positioning
devices with your ungloved hands). Optional: If
the patient is missing a few teeth and you
would like to use cotton rolls for
stabilization, then open the bag at this point
and spill the cotton rolls onto the tray
cover.
- Turn on the X-ray machine, confirming that
the kVp and mA are correct.
- Place the lead apron and thyroid collar on
the patient.
*Remember that these four steps must be
complete before you put on gloves:
- prepare sensors.
- open positioning device bag and spill
contents on tray cover.
- turn x-ray machine on, confirming
settings.
- place lead apron and thyroid collar on
patient.
Put gown on, wash hands and put on gloves and
mask (if wearing).
With gloves on:
- Log into axiUm, select patient from the
Rolodex. In the Radiology Clinic, axiUm would
already be open at the imaging chair.
- Select the MiPacs icon in the patientās
electronic health record. Double check
at the top of the screen that the correct
patient is selected.
- Select a template to acquire the images
into. This is done by clicking the arrow down
on the right of the template description, and
selecting the desired template. In the
Radiology Clinic, this will be the FMS 20
template.
- Select the āShow templateā icon, found to
the left of the template description in the
menu bar.
- Confirm that the CMOS sensor is active,
noting that the circle at the top on the right
of the menu bar is green.
- Assemble the positioning devices.
- Position the CMOS sensor into the
appropriate device, so that the correct side is
directed toward the tube head.
- Make sure that the correct image position
in the template is highlighted red, indicating
where the image will be inserted upon exposure.
If it is not, reselect by clicking with the
mouse.
- Position CMOS sensor/positioning device
assembly into the patientās mouth, placing the
cord between the headrest and the back
of the patientās head, to prevent it
from falling and striking the ground, while
ensuring that it is not pulled
tight and thereby inadvertently
pulling it out of the port. Make sure that the
cord projects towards the occlusal plane in the
anterior region and out of the mouth in the
posterior region. *Use size#1 for the anterior
and size #2 for the posterior.
- Exit the operatory, adjust exposure time
appropriately according to mounted chart and
press and hold the button to expose the
image.
- Re-enter the operatory and view the image
on the computer monitor. Even if errors
are identified at this point, under NO
CIRCUMSTANCES should a retake be made without
instructor approval.
- Reposition the CMOS sensor/positioning
device assembly to the next position, and
continue exposing images.
*Note that the RINN device must be reassembled
depending on the quadrant imaged, and the size of
the CMOS sensor is changed when imaging the
anterior (size #1) and the posterior (size
#2).
- When all images have been completed with
the first sensor, remove it from the
positioning device and carefully place it back
into its container, so that the entire sensor
and cord is within the container.
Remove gloves and unplug it
from the USB hub. Carry the container back to
the main counter.
- Carry and place the container with the
second sensor onto the shelf/window. Plug the
sensor into the USB hub.
- Re-wash hands and
reglove.
- Complete all image exposures following the
same procedure (steps 15-19).
- Save images and close
MiPacs: You may click on āSaveā icon,
or simply close MiPacs by clicking the X and
you will be prompted to save all images.
Students cannot approve images. If a dialogue
box opens requesting a user name and password
for approving images, select āCancelā or āDonāt
approveā.
- Remove gloves and optional
mask and return to the viewing room, where
you will review, assess and discuss
the images.
In the Viewing Room:
Steps to review and approve images
- Ensure that axiUm is open with the correct
patient selected. Open MiPacs. Select the new
series to review from list on left of screen.
This should be the series with a red
triangle.
- Self-evaluate the images, making note of
any deficiencies and the need for retakes.
- Ask an instructor to review the images. If
it has been determined that retakes are
required, on the template screen in MiPacs,
drag the insufficient images down to the
overflow area. This will leave the specific
location in the template empty, and ready for
re-imaging. Close MiPacs.
No changes should be made to the
images (i.e. density or contrast) in the
unapproved state. Any changes that are made
should be undone using the āUndo Allā icon, while
all images are selected.
- Return to the operatory and follow the
steps to expose the retakes or new images, as
outlined above. Corrected images are added to
the original series. Prior to re-imaging, you
will need to check to ensure that the barriers
are still covering the sensor(s), and that they
are not damaged prior to re-use.
Making adjustments to series
mounting in MiPacs
-
The series must be mounted correctly
prior to approval.
- Unapproved images can be dragged to
different positions within the
template.
- Rotations can be done as required to
reflect the proper anatomic position, using
āRotate 90 degrees clockwiseā icon.
- Any retaken images that are not
diagnostically useful should be pulled out
of the template, and dragged into the
overflow area at the bottom.
- If you have taken more images than fits
in the original template, or wish to
include the original retake with the
corrected view, remount the series.
Accomplish this by selecting a new
appropriate template and choosing āRemount
current seriesā.
This will cause all images to drop into the
overflow area. Remount the images into the new
template into the appropriate positions and
orientation.
- Once images are confirmed to be
adequate and mounted correctly, select
all images to ensure that no changes (ie.
density or contrast) have been made purposely,
or inadvertently, and click the āUndo Allā
icon. The clinical instructor can then approve
the series in MiPacs.
Return to the
operatory:
- Hang up the lead apron and thyroid collar
on the hooks provided, and dismiss the patient.
Cleaning the operatory:
- Put on your gown and a new pair of gloves.
Discard all disposables, dis-assemble the
positioning devices and wash and leave in sink.
DO NOT turn off the X-ray unit (this is how
staff identify which units need to be cleaned).
Place sensor(s), barrier wrapped in their
correct plastic containers and return to the
dispensary where you will obtain your
tag(s).
- Complete the Image Request in axiUm.
- Complete Chart Add to add the treatment
code for radiographs taken (necessary to
trigger patient billing) and if applicable the
re-take imaging code. The instructor will then
swipe to complete this and enter the Technique
Evaluation.
The author would like to acknowledge the
significant contributions of Dr. Karen Aiken and
Mrs. Andrea Welsh to the article.
Article Reviewed By
Dr. Ross Barlow and Mrs. Andrea
Welsh