Well, it would be possible but only if the video format in the torrent allowed for this is a way compatible with the way torrent transfers are split into blocks - i.e. it has a block structure that lines up with the torrent block structure such that block X is enough to play a given set of frames at the lowest quality, block X+1 for better quality, and so forth.
The blocks wouldn't have to be sequential: as torrent transfers are essentially random access you could have the content required for lowest quality display at the start of the file and the extra data further on, similar to how FLIF supports almost immediate low quality with progressive improvement as the rest of the file arrives (http://flif.info/ - see the video demo part way down that page, or https://uprootlabs.github.io/poly-flif/ for a more interactive look at how it copes with truncated files).
I'm not aware of any video formats that are arranged this way though. Those that are designed for adaptive streaming have a more dynamic structure that would not align well with the torrent protocols blocks.
Torrents are usually one file, which would not allow Adaptive Bitrate Streaming.