There are proprietary image file formats the 3D Slicer does not recognize and so refuses to load. @nagy.attila in collaboration with Slicer core developers created an extension that can be used to load data from files that use an unknown format.
RawImageGuess extension offers a number of parameters (image header size, dimensions, pixel type, etc.) that users can adjust and see the resulting image in real-time. This makes it possible to guess the image format in a couple of minutes.
See a demo video that shows how to guess format of a Samsung .mvl 3D ultrasound image:
The extension is available in the extension manager for latest Slicer Preview Release.