盘状半月板MRI分型及其表现分析

目的:探讨盘状半月板MRI表现及其分型特点,提高盘状半月板MRI诊断率.材料和方法:将70例行MRI检查并经关节镜证实的盘状半月板分为未成年组、成年组.对全部病例冠状面髁间棘层面半月板宽度与胫骨平台宽度之比(板面比)、矢状面层厚4mm扫描"领结样"改变层数及"领结样"改变最宽层面前后径宽度进行测量、分析.根据盘状半月板MRI表现分为板型、楔型、肥角型.结果:70例盘状半月板中未成年组30例、成年组40例,板型33例、楔型19例、肥角型18例,69例发生不同程度撕裂.整组病例板面比≥20%(P<0.01),各型年龄分布无显著性差异(P>0.05),各型矢状面"领结样"改变最宽层面不全相同(P<0.05).结论:板面比≥20%诊断盘状半月板最可靠,矢状面层厚4mm扫描"领结样"改变层数≥3诊断盘状半月板易发生漏诊,矢状面"领结样"改变最宽层面楔型较肥角型大,年龄可影响盘状半月板分型.

MRI Classification and Manifestations of Discoid Meniscus

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% (P<0.01) in all of cases.No significant difference in the incidence of each type existed between two groups(P>0.05).Significant difference in the incidence of each type existed in c(P<0.05).Conclusions: a >or = 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.