• data is taken as is (see also comment to T27568)
• I'd say the probably correct description would be 2D-Realtime B-Mode where images are made at a constant frame rate (20 fps in the case of the Canon video). If you consider moving the transducer over the body it not necessarily results in a 3D image, more 2D+t - if you keep the transducer at a fixed spot and e.g. only tilt the tranducer, it is more 3D like.
• I am not aware that there are sensors in the transducer that would give us its position and orientation in space
• Is e.g. a "Play" button for the z-dimension a possible solution?

In T27570#206547, @kleesiek wrote:

• data is taken as is (see also comment to T27568)
• I'd say the probably correct description would be 2D-Realtime B-Mode where images are made at a constant frame rate (20 fps in the case of the Canon video). If you consider moving the transducer over the body it not necessarily results in a 3D image, more 2D+t - if you keep the transducer at a fixed spot and e.g. only tilt the tranducer, it is more 3D like.
• I am not aware that there are sensors in the transducer that would give us its position and orientation in space

Yes you are right. I thought to much in the lines of CAMIs work.

• Is e.g. a "Play" button for the z-dimension a possible solution?

Technically yes. Currenty something like that is implemented in VideoMaker plugin. But currently such general controll plugin is yet not available.

If looked a bit closer. The time information is encoded in Tags of the MultiFrame and the CINE module.

In this case

• Number of Frames (0028,0008)
• Frame Increment Pointer (0028,0009) -> Pointing to Frame Time
• Frame Time (0018,1063)

So we could rework the generation of time geometry and volume seperation according to that information. But I also think that it will point to dedicated US reader, that handles this case of US Multi-frame Image CIOD for 2D+t images, as it might make the business logic to complex for the general reader if it should also be deduced and covered. But I must have a closer look on the current reader (may be also in conjunction with T27432).

For US images we should add at least the following tags of interest.

result.insert(MakeEntry(DICOMTag(0x0008, 0x2142))); //cine start time
result.insert(MakeEntry(DICOMTag(0x0008, 0x2143))); //cine stop time
result.insert(MakeEntry(DICOMTag(0x0018, 0x1063))); //cine frame time
result.insert(MakeEntry(DICOMTag(0x0018, 0x1065))); //cine frame vector
result.insert(MakeEntry(DICOMTag(0x0018, 0x1066))); //cine frame delay
result.insert(MakeEntry(DICOMTag(0x0028, 0x0008))); //number of frames
result.insert(MakeEntry(DICOMTag(0x0028, 0x0009))); //frame increment pointer