This format is used by newer versions of the Analyze medical imaging software (version 2.5 or higher). Previous versions used the Analyze 7.5 format, where image data and header information were stored in different files. The Analyze AVW format can be used to store 2D, 3D, and 4D medical images, but the 4D time series option is currently not supported in amira. Additional attributes stored in the files (like patient name or examination time) are stored in the parameter section of the generated amira data objects. Analyze AVW files are safely recognized by inspecting the file header. The common file name extension is .avw.
Besides Analyze AVW image files sometimes also so-called Analyze AVW volume files are used, which contain a list of 2D file names forming a 3D image stack. Such volume files currently cannot be interpreted by amira. However, note that amira provides a very similar concept with the Stacked-Slices format.
Amira exports scalar and color fields with uniform coordinates to the Analyze AVW format. Other coordinate types can be written as well, but in these cases the coordinate information will be lost and no accurate recovery will be possible.