fo-dicom is also available on the Unity platform, see here. The Unity assembly does not support asynchronous methods, networking (due to the missing asynchronous support) or JPEGx compressed codecs (due to missing third party codec libraries), but it does support Unity specific image rendering, limited compressed codecs (RLE) and the latest DICOM dictionary, 2016e.
The fo-dicom package on the Unity Asset Store comes with a small fee. If you want to try out a "no-charge" version, you can build the DICOM.Unity solution in the fo-dicom repository from source. Note that the Unity version on Github only contains a non-functional implementation of image rendering to Unity's Texture2D class. For full functionality, the Asset Store version is required.