>Fields, as in scientific fields? Are there any that still commonly use imperial units at all?

More industrial fields, but it's still pretty common in engineering R&D in fields where the academic, scientific, and industrial lines get blurred.

Automotive and Aerospace engineering, for example.

>Are there any that still commonly use imperial units at all?

Aerospace is still overwhelmingly Imperial, at least until you get to space. Altitudes are measured in feet, speed in knots, thrust and payload in pounds, power in horsepower (particularly for piston-cylinder engined aircraft).