Welcome everyone my name is Shannon and i'm a sonographer working in general
imaging applications at Philips. In this video, we will look at the four main steps for effective use
of ElastQ imaging for liver stiffness assessment. Philips EQI is a Shearwave based technique
which provides real-time feedback, confidence and quantification and speed to advance the use
of elastography in clinical practice. Philips has developed two Shearwave techniques, ElastPQ
and ElastQ imaging. ElastPQ has proven valuable in staging liver disease
and reducing the need for costly and painful biopsies in some patients. ElastQ imaging advances
Shearwave elastography providing a technique that is not only non-invasive and easy to use,
but also offers clinicians additional confidence in the reliability of measurements.
For an effective use of EQI, Philips developed a robust protocol including patient's preparation
acquisition, advice sampling strategy and interpretation guidance. This protocol
reflects feedback from expert users and worldwide guidelines.
The first step is all about the patient's preparation.
For start, please make sure that the patient has been fasting for at least six hours, then
position the patient so it increases the rib space and provides an optimal window of acquisition.
Supine or left lateral oblique position with the right arm and maximal extension is recommended.
Once your patient is in an optimal position you can proceed and enter patient name,
select the C5-1 transducer and the customized ElastQ preset. This will include abdomen gen
preset settings, a 6 second cine loop and 12 centimeters of depth. Before starting your exam,
you always have the option to choose the units of your measurements. Indeed within
setup, you can select meters per second or kilopascals at default on all of your exams.
For an optimal acquisition we like to recommend to start by finding the segment of the liver
where you would like to make your measurements. Ensuring good transducer contact with adequate gel
will help you. Then position the transducer in the right intercostal space and aligned with the ribs.
Image liver segment 7 or 8 and keep the liver capsule parallel to the transducer surface.
We recommend to avoid scanning the left side of the liver, as cardiac motion leads to inaccurate
results. Look for a section of the liver with fewer vessels and little hypoechogenic structures
such as the gallbladder or the bile ducts. You can now begin the Shearwave assessment.
Select the elasto control at the bottom of the touch panel. Position the ROI box in the center
of the image and 1.5 to 2 centimeters below the liver capsule. Do not place the ROI box
on or near a rib shadow or the liver capsule, as it might generate reverberation artifacts.
Ask the patient to pause breathing in a relaxed manner rather than taking and holding a deep
breath. We recommend a practice phase to show the patient when the liver is stable.
You do not want the patient to take a deep breath in or out. Once you are comfortable
wait for a stable image and acquire a cine loop with a minimum of six second length.
You have already acquired reliable cine loops, the second step is about placing the sampling calibers
in the most representative area so you collect robust and reproducible stiffness measurements.
Start by reviewing the acquired cine loop to identify frames where the tissue is stable and the
color-coded stiffness velocity map is consistent. Measure areas of most representative colors that
change the least over time. Avoid measuring over rib shadows or areas near blood vessels.
Verify that the calipers are placed in areas with high confidence, green on the confidence
map. Take no more than two measurements on one frame per cine loop acquisition.
One last step is required before you can start the interpretation of the results. For a reliable
evaluation of liver stiffness, measurements should be acquired from multiple cine loops of the right
lobe. For each cine loop pick a single frame where no more than two calipers should be placed.
Once at least five calipers on five different frames have been acquired, refer to the median
across the sampling calipers. It eliminates the outliers. You will find the median in the patient
report. Refer to the IQR over median as a quality criterion for measurements in KPA. Anything
less than 30% provides strong confidence in your sampling measurements. I just showed the effective
use of Philips EQI which offers a non-invasive and easy to use Shearwave technique for confident
liver stiffness assessment. Thank you for watching, I hope that you enjoyed this video.