elastq imaging | liver quick guide confidence map & threshold · ultrasound the color-coded...
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Quick Guide
Ultrasound
The color-coded Confidence Map reflects a value for each pixel, providing an indication of quality across the stiffness value map. This assists the user in obtaining measurements from the areas with the highest shear wave quality.
Every pixel in the ROI is assigned a confidence value from 0 to 100 and a corresponding color between red and green. Low values (red) indicate that the stiffness value for a given pixel is less reliable. High values (green) indicate that the stiffness value for a given pixel is more reliable.
Several factors can lower the confidence value: tissue areas with blood flow (vessels), low echogenicity (such as the gallbladder), low shear wave strength (as when scanning deep in the Technically Difficult Patient), or with large tissue motion (as with no breath pause). The confidence map reflects shear waves strengths but may not detect ultrasound artifacts such as reverberation and rib shadowing artifacts.
Use of the confidence map can enhance the exam if the scan technique is optimal, but it cannot overcome suboptimal scanning technique. Examples of suboptimal scanning technique are placing the ROI and taking measurements within 1.5 cm of Glisson’s capsule (producing a reverberation artifact) or placing the ROI on the edge of a rib or lung shadow.
We recommend to turn on the confidence map to verify that the calipers that are placed on the stiffness map are in areas with high confidence (green on the confidence map).
Confidence Map
Confidence Threshold
The Confidence Threshold sets those areas of a stiffness/velocity image with lower confidence as transparent. For example, setting the confidence threshold to 60% will set areas of a stiffness/velocity image with a confidence value of less than 60% as transparent. The transparent areas will not be measured. Changing the confidence threshold will not change the confidence map.
A Confidence Threshold of 60% is recommended.
Press the Confidence Map button to enable/disable the Confidence
Map function.
Turn this rotary to
adjust the Confidence Threshold.
Confidence Map ElastQ image mapping tissue stiffness
Turn this rotary for additional
color enhancements.
EPIQ Elite Release 4.0
ElastQ Imaging | LiverConfidence Map & Threshold
Confidence Map & ThresholdConfidence Threshold
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