I have flown this jet with United and on most flights they gate check rolling bags and usually other larger carry on bags if you also have a personal item. The overheads are pretty tight and the information below from American Eagle shows the dimensions which I assume are similar for other airlines as well.

Bombardier CRJ-700 Storage

While Carry-on capacity is limited to smaller briefcase and purse sized pieces, all American Eagle aircraft feature our popular planeside Valet service for those larger pieces of carry-on luggage.

Area Cabin Width Height Depth
Under seat
First 33" 16.5" 10.5"
Main 33" 16.5" 10.5"

Overhead Bin
First 52.5" 14" 9.5"
Main 52.5" 14" 9.5"