Contrast Enhanced Ultrasound: Technical Top Tips
Dr Gibran Timothy Yusef, from Kings College London shares his top tips for Contrast Enhanced Ultrasound.
- Use the correct dosage: Determine what dose you require prior to starting, too much contrast agent will create flare whilst too little may lead to inadequate enhancement. Commonly (using SonoVueTM, Bracco) 2.4ml is used for the liver, 1.2ml for the kidneys, 4.8ml for microvascular uses e.g. testis. Intracavity use requires only 0.1ml diluted in up to 50ml of solvent (e.g. normal saline)
- Turn down the gain: Having the gain too high prior to commencing a CEUS examination in contrast specific mode will increase the artefact present, including that seen from very hyperechoic regions (such as bowel gas) which may cause interpretation error. Adjusting the gain prior to administering contrast will provide greater resolution of the contrast agent within the vasculature/lumen ensuring you have as close as possible to a truly contrast specific image.
- Optimise Mechanical index: Too high a mechanical index will lead to bubble destruction, particularly in the near field. Too low a mechanical index will result in poor visualisation of the far field and may hide pathology. Make sure the mechanical index is optimised for the area you are trying to visualise.
- Record a video clip: A great benefit of CEUS is its dynamic nature, but it can be easy to miss the early arterial phase which is of particular importance in CEUS of liver lesions. Recording a video clip, using a timer and reviewing the clip later can be helpful to make sure the arterial phase is seen clearly.
- Avoid prolonged scanning: Prolonged scanning in a single plane results in microbubble destruction, particularly the near field and slow flow vessels. This may simulate washout in liver lesions and result in misinterpretation of findings. It helps to scan intermittently after the arterial phase.
If you want to learn more about CEUS we are running, in partnership with Kings College London, A EUROSON School CEUS Course: How to incorporate CEUS into your imaging practice, click here for the programme and booking information