Aliza is described as 'Medical Imaging for Linux and Windows. Open 2D, 3D and 4D images in DICOM, MetaImage, Nifti, Nrrd and other formats. Front-end for registration with Elastix and many more features'. There are three alternatives to Aliza for Mac, Windows, iPad, iPhone and Linux. The best alternative is OsiriX. It's not free, so if you're looking for a free alternative, you could try AMIDE or Athena DICOM Viewer.
Athena DICOM Viewer is a breakthrough medical imaging software, an evolution of DICOM Viewers. Developed to high production, Athena incorporates many useful resources, shortcuts and tools to have a better diagnostics and increase production.