MRI Classification and Manifestations of Discoid Meniscus / 中国医学影像学杂志

ABSTRACT

Purpoes To discuss the MRI manifestation and classification of discoid lateral meniscus and improve the accuracy of MRI diagnosis for discoid meniscus.Materials and Methods: 70 cases of discoid meniscus verified by arthroscopy were divided into impuberal group(n=30) and adult group (n =40).Following three quantitative parameters were measured.The meniscal width and tibial plateau width on the coronal slice showing the inttercondyloid spine( a),the number of the spine showing butterfly change when the layer thickness was 4mm(b) and the maximum width showing butterfly change on the sagittal slice(c).The discoid meniscus were classified as slab type (n=33),wedge type(n = 19),hypertrophied - horn type(n= 18) according to their shape.Results:69 cases had torn in different extent,a>or =20% (P0.05).Significant difference in the incidence of each type existed in c(Por = 20% is the most reliable criterion to diagnose discoid meniscus.Using b as the criterion of discoid meniscus is easy to occur missed diagnosis,c in the wedge type is bigger than the one in the hypertrophied type.Age can impact the classification of discoid meniscus.