title: Hypointense signal lesions of the articular cartilage: a review of current concepts.
abstract: Discussion of articular cartilage disease detection by MRI usually focuses on the presence of bright signal on T2-weighted sequences, such as in Grade 1 chondromalacia and cartilage fissures containing fluid. Less emphasis has been placed on how cartilage disease may be manifested by dark signal on T2-weighted sequences. The appearance of the recently described "cartilage black line sign" of the femoral trochlea highlights these lesions and further raises the question of their etiology. We illustrate various hypointense signal lesions that are not restricted to the femoral trochlea of the knee joint and discuss the possible etiologies for these lesions.
authors.affiliation: Department of Radiology, Community Division, University of Wisconsin, Madison, WI. Electronic address: keegan.markhardt@gmail.com.
authors.forename: B Keegan
authors.initials: BK
authors.lastname: Markhardt
authors.affiliation: Department of Radiology, VA San Diego Healthcare System, San Diego, CA; Department of Radiology, University of California, San Diego Medical Center, San Diego, CA. Electronic address: ericchangmd@gmail.com.
authors.forename: Eric Y
authors.initials: EY
authors.lastname: Chang
mesh_terms: D016880:Anisotropy; D002357:Cartilage Diseases / Q000175:diagnosis*; D002358:Cartilage, Articular / Q000473:pathology*; D006801:Humans; D007719:Knee Joint / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*
keywords: Anisotropy; Black line; Cartilage; MRI; Magnetization transfer