3D/4D Echo White paper - List of use cases

List of 3D/4D Echo use cases

Below is an initial list of clinical use cases for which 3D/4D Echocardiography is relevant.

In the context of this whitepaper we will be focussing on interactions between the sonographer at the scanner and the reading physicin at a review workstation. The overall clinical workflow (including patient admission, ordering, scheduling, image acquisition, storage and reporting) is covered in the Echo workflow and will be most likely the same for 3D/4D Echo workflow. The critical part for 3D/4D workflow is on the review of the 3D/4D datasets and the interaction with the volume data.

3D Quantification of chambers

It is proven that 3D quantification of the cardiac chambers is more accurate and reproducible for multiple reasons:

• No geometric modelling is necessary
• Improved endocardial visualization

Parameters to be quantified:

• LV ejection fraction
• LV mass
• LA and RA volume
• RV volume
• Note: are there additional parameters which have not conventionally been used on 2D

Basic steps:

• On the scanner:
  • User queries modality worklist and selects patient/procedure
  • User acquires a volume clip together with the associated ECG waveform
  • System stores the volume clips and associated ECG locally
  • User opens volume into review
  • system displays volume data synchronized with external ECG waveform
  • User performs chamber quantification
  • System saves measurements and calculations in DICOM comprehensive SR (TID 5200 or 5300) and marks them as 3D measurments.
  • User archives study to the local PACS system
• At the review workstation
  • User retrieves study and opens it
  • User selects a volume and opens it
  • System displays volume synchronized with external waveform and measurements.
  • User reviews volume data and measurements
  • User performs additional measurements and derives some more views of the volume.
  • User ends study and stores additions back to the archive
  • User reviews volume data and measurement data

Open issues:

• workflow must accomodate for manual, semi-automated, and automated methods to calculate chamber volumes. Depending on the method used, different requirements for derived views (and therefore presentation states) may apply (eg what is the starting point for manually tracing views or for semi-automated algorithms? Are spefic views needed, if so I assume it should be based on MPRs of standard views.)
• Are there additional volume measurements which do not exist currently in 2D Echo
• How are 3D measurements encoded (3D modifier?)
• How are volume data represented to the user when he opens them
• Do we need to store derived views with outlines?
• Annotations inside of image