正常和损伤膝关节半月板低场MRI研究(附损伤半月板关节镜所见比较)

目的:认识正常膝关节半月板低场MRI表现并提高对损伤半月板诊断的正确率。方法:20例正常膝关节按年龄分成5组,观察半月板及关节软骨的信号并测量其厚度。根据正常半月板及关节软骨的低场MRI征象,结合本组41例半月板MRI和关节镜检查的对照研究,参照Stoller半月板退变和损伤的MRI分级标准,拟订了损伤半月板低场MRI诊断标准,即半月板退变、半月板单纯撕裂和复杂撕裂,统计学采用t检验。结果:低场MRI显示正常半月板内线条状高信号,不延伸至关节面或游离缘,半月板和关节软骨的厚度随年龄不同而变化。低场MRI对损伤半月板诊断的正确率为92.68%(38/41)。结论:拟订的半月板损伤低场MRI诊断标准具有简明、扼要、实用性强的特点,值得临床推广应用。

The study of normal and injured meniscus of knee with low field MRI(comparison with arthroscopy)

Objective: To recognize normal meniscus and improve diagnostic accuracy about injured meniscus with low field MRI. Methods: Twenty volunteers were divided into five groups according to age. The figure and signal of the meniscus and cartilage were showed, the thickness of the anterior, posterior horn, body of the meniscus and cartilage were measured on sagittal and coronal SE T1WI. T-test was used statistically. According to MR imaging of normal meniscus, Stoller's grade standard and combining comparison study of MRI with arthroscopy in this article, the diagnostic standard was made, that is, degeneration, single tear and complex tear of meniscus. Results: The normal figure of meniscus was triangular and the thickness of meniscus and cartilage differed from different age, the meniscus had lineal high signal not to reach the articular surface and the cartilage had homogeneous signal and smooth edge. The diagnostic accuracy of injured meniscus was 92.68%(38 41) with low field MRI. Conclusion: The diagnostic standard of injured meniscus is simple, accurate, practical and had clinical significance in diagnosing injured meniscus of knee.