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4. Treatment methods > 4.6. Motion detection
4.6.1. Misplaced heating or motion artefact?
If the temperature increases significantly outside the intended heating volume, the system issues
warnings. The warnings may be caused by movement or other artifacts and their reason and safety
consequences should be understood before continuing with the treatment.
Breathing or bowel movements may produce artefacts which look like heating in the temperature
images and trigger motion detection warnings.
The figures below show temperature images where sonication is in progress but bowel motion
interferes with the temperature imaging.
If there is any doubt about the cause of the perceived heating, immediately abort the sonication
using the software abort button and run a temperature scan without any heating. If the temperature
does not seem to decrease, the perceived heated region may be caused by an artefact and
treatment can resume with caution.
Ways to distinguish motion artefacts from heating:
Run temperature mapping scans before the Therapy stage and in between sonications.
Use the transducer beam overlay to check the location of the colored areas. If they are outside
the beam path, they are most likely artefacts caused by motion.
Scroll the time series to determine whether the perceived heating occurred during sonication.
In the following example image actual heating has taken place at the heated area at the ultrasound
beam focus. The areas colored yellow or red far from the transducer beam are motion artefacts.
Instructions for Use
109745C2 / 02-2022
Fig. 21: Motion artefacts in temperature mapping images.
Fig. 22: Heating and artefacts in temperature map
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