They are used in OCT (optical coherence tomography) as well

OCT is a technique which uses IR to get "through" tissue using beam in the near infrared (roughly 950 nm, with a spread of roughly 100 nm). The return is passed through interferometer and what amounts to a diffraction grating to produce the "spread" that the line camera sees. After some signal processing (FFT is a big one), you can get the intensity at depth. If you sweep in X,Y somehow, usually deflecting the beam with a mirror, you can obtain a volumetric image like an MRI or sonogram. Very useful for imaging the eye, particularly the back of the retina where the blood vessels are.

Yah, lots of neat line scan camera applications in spectroscopy. Basically any grating application. 950nm would be on the edge of where you'd implement a Si CCD for OCT as the sensitivity drops as the Si is no longer absorbing. InGaAs detectors are used further in the NIR.