Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Nov 28, 2018; 10(11): 162-171
Published online Nov 28, 2018. doi: 10.4329/wjr.v10.i11.162
New scoring system in assessment of Hoffa’s fat pad synovitis: A comparative study with established scoring systems
Shigeo Hagiwara, Albert Yang, Shoichiro Takao, Yasuhito Kaneko, Taiki Nozaki, Hiroshi Yoshioka
Shigeo Hagiwara, Albert Yang, Shoichiro Takao, Yasuhito Kaneko, Taiki Nozaki, Hiroshi Yoshioka, Department of Radiological Sciences, University of California Irvine Medical Center, Orange, CA 92868, United States
Author contributions: Yoshioka H involved in overseeing the data collection process and data analysis following the data collection; Hagiwara S and Takao S accessed to subject identifiable data and analyzed the data; all the authors have read the manuscript and have approved this submission.
Institutional review board statement: The research protocol of this retrospective study was in compliance with the Helsinki Declaration, was approved by the institutional review board, and was registered with the University of California Irvine Medical Center.
Informed consent statement: The waiver of informed consent was granted by the institutional review board, the University of California Irvine Medical Center.
Conflict-of-interest statement: No conflict of interest to be disclosed.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Hiroshi Yoshioka, MD, PhD, Chief Doctor, Professor, Executive Vice Chair, Department of Radiological Sciences, University of California Irvine Medical Center, 101 The City Drive South, Orange, CA 92868, United States. hiroshi@uci.edu
Telephone: +1-877-8243627
Received: August 4, 2018
Peer-review started: August 5, 2018
First decision: August 24, 2018
Revised: September 22, 2018
Accepted: October 6, 2018
Article in press: October 6, 2018
Published online: November 28, 2018
Abstract
AIM

To investigate the reliability of the established and new scoring methods for Hoffa’s fat pad synovitis using magnetic resonance imaging (MRI).

METHODS

A total of 139 knees of 115 patients who underwent MRI of the knee with and without gadolinium contrast were enrolled in this study. Proton density (PD)-weighted, PD-weighted fat-suppressed (PD-FS), and postcontrast T1-weighted fat-suppressed (T1CE) images were used for evaluation. Using contrast and non-contrast images, our grading method for synovitis was performed to measure synovial thickness and signal intensity changes of the fat pad [Synovial membrane (SM) score], which was compared with the established methods, including MRI Osteoarthritis Knee Score (MOAKS), parapatellar synovitis score, Whole-Organ Magnetic Resonance Imaging Score (WORMS), and suprapatellar effusion diameter. Intraclass correlation coefficients (ICC) for intra and interobserver reproducibility and Spearman correlation coefficients (r) were calculated for the parapatellar synovitis score and each scoring method.

RESULTS

All of the scores presented substantial to almost perfect intrareliability. Among three readers, effusion diameter had substantial to almost perfect interreliability (ICC = 0.68-0.81) and WORMS had substantial interreliability (ICC = 0.61-0.70). For two out of three readers, there was substantial interreliability for the thickness score in T1CE (ICC = 0.55-0.69), SM scores in T1CE (ICC = 0.56-0.78) and PD-FS (ICC = 0.51-0.79), and parapatellar synovitis score in T1CE (ICC = 0.53-0.72). The parapatellar synovitis score was significantly correlated with the thickness score in T1CE (r = 0.70) and the SM score in T1CE (r = 0.81) and PD-FS (r = 0.65).

CONCLUSION

The newly proposed quantitative thickness score on T1CE and the semi-quantitative SM score on T1CE and PD-FS can be useful for Hoffa’s fat pad synovitis.

Keywords: Magnetic resonance imaging, Hoffa’s fat pad synovitis, Semiquantitative score, Quantitative score, Scoring system

Core tip: We proposed a new grading method for Hoffa’s fat pad synovitis and compared it with the other established methods. Our method showed substantial to almost perfect reproducibility and significant correlations with the established methods for both non-contrast and contrast images. Our newly proposed scoring system method can be useful for Hoffa’s fat pad synovitis.