The imaging findings are consistent with a complete or high-grade proximal rectus femoris tendon tear with tendon retraction, surrounding the fluid collection, edema, and muscle strain, primarily at the musculotendinous junction.

A grading scheme that is commonly used for MRI includes ¹:

• grade 1: high signal intensity, either localized or diffuse, or feathery muscle edema without disruption of fibers

• grade 2: partial tear of the muscle-tendon junction with disruption of some fibers

• grade 3: complete tear of the muscle-tendon junction, with or without tendon retraction