Medial collateral ligaments (MCL) tears can be graded into 1, 2, and 3, with 3 being indicating complete disruption.  

Intermensical fluid signal must contact an articular surface to be diagnostic for an MRI tear.  Classically this was stated on 2 or more consecutive slices, however, with smaller slice thickness MRI, meniscal tear morphology is favored by many to make a diagnosis.