1 Department of Medicine, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
2 Department of Radiology, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, 892 Dongnam-ro, Gangdong-gu, Seoul 134-727, Republic of Korea.
AJR Am J Roentgenol. 2017 Dec;209(6):1321-1330. doi: 10.2214/AJR.16.17718. Epub 2017 Oct 18.
The purpose of this study was to determine the validity of infrapatellar fat pad (IPFP) opacity grading based on lateral knee radiography for assessing knee synovitis using correlation with contrast-enhanced (CE) MRI.
Retrospective reviews of radiographs and CE knee MR images from 79 patients were independently performed by two radiologists. They evaluated IPFP opacity alteration (IPFP) and joint effusion grades on lateral knee conventional radiographs, IPFP signal intensity alteration (IPFP) and joint effusion grades on CE MR images, and synovitis (SYN) grade in nine divided regions, three compartments (parapatellar, periligamentous, perimeniscal), and the whole knee on CE MR images. Correlations between radiographic grades and MRI assessments were evaluated using Spearman correlation tests, and the correlation coefficients (ρ) were compared. Interobserver agreement was evaluated using weighted kappa values.
The IPFP grade was very highly correlated with the IPFP grade (ρ = 0.906, p < 0.001) and highly correlated with SYN grades from four regions (suprapatellar, infrapatellar, intercondylar, lateral parapatellar recess), the parapatellar compartment, and the whole knee (ρ = 0.614-0.740, all p < 0.001). The IPFP grade was moderately correlated with the SYN grades of the remaining five regions and two compartments (ρ = 0.457-0.547, all p < 0.001). The differences between correlation coefficients for SYN grades and the IPFP and IPFP grades were not statistically significant (p = 0.290-1.0). Interobserver reliabilities were excellent or good for IPFP, IPFP, and SYN grades (κ = 0.661-1.000).
IPFP grade assessment enables valid evaluation and reporting of knee synovitis, especially in the parapatellar compartment and the whole knee.
本研究旨在通过与对比增强（CE）MRI 相关性来确定基于外侧膝关节 X 线摄影的髌下脂肪垫（IPFP）不透明度分级评估膝关节滑膜炎的有效性。
对 79 例患者的 X 线和 CE 膝关节 MRI 进行回顾性分析。由两名放射科医生独立评估外侧膝关节常规 X 线片上的 IPFP 不透明度改变（IPFP）和关节积液分级、CE 磁共振图像上的 IPFP 信号强度改变（IPFP）和关节积液分级，以及 CE 磁共振图像上的九个分区（髌上、韧带周围、半月板周围）、三个间室（髌旁、韧带周围、半月板周围）和整个膝关节的滑膜炎（SYN）分级。采用 Spearman 相关检验评估 X 线分级与 MRI 评估之间的相关性，并比较相关系数（ρ）。采用加权 Kappa 值评估观察者间一致性。
IPFP 分级与 IPFP 分级高度相关（ρ=0.906，p＜0.001），与四个分区（髌上、髌下、髁间、外侧髌旁隐窝）、髌旁间室和整个膝关节的 SYN 分级高度相关（ρ=0.614-0.740，均 p＜0.001）。IPFP 分级与其余五个分区和两个间室的 SYN 分级中度相关（ρ=0.457-0.547，均 p＜0.001）。SYN 分级与 IPFP 和 IPFP 分级的相关系数差异无统计学意义（p=0.290-1.0）。IPFP、IPFP 和 SYN 分级的观察者间可靠性为优或良（κ=0.661-1.000）。
IPFP 分级评估能够对膝关节滑膜炎进行有效评估和报告，特别是在髌旁间室和整个膝关节。
