Published online Nov 28, 2018. doi: 10.4329/wjr.v10.i11.162
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
Osteoarthritis (OA) of the knee is one of the most common chronic disorders resulting in pain, deformity, and loss of function. Several semiquantitative methods using magnetic resonance imaging (MRI) for assessment of knee OA have been developed and used in various observational studies and clinical trials.
Although all assessment methods had been reported to be clinical useful, their reliability was not perfect, and the scoring for Hoffa’s fat pad synovitis based on non-enhanced sequence has not been sufficient, compared with that for the other subregions of the knee.
The aim of this study was to evaluate the reliability of the established and new scoring methods, including non-enhanced MRI, for Hoffa’s fat pad synovitis.
This study enrolled 139 knees of 115 patients who underwent MRI of the knee with and without Gadolinium contrast. Proton density (PD)-weighted, proton density-weighted fat-suppressed (PD-FS), and postcontrast T1-weighted fat-suppressed (T1CE) images were used for evaluation. Our grading method for synovitis was performed using non-contrast and contrast images to measure synovial thickness and signal intensity changes of the fat pad (SM score). Intraclass correlation coefficients (ICC) for intra and interobserver reproducibility and the Spearman correlation coefficients (r) with the parapatellar synovitis score were calculated for each scoring method.
The thickness score in T1CE and the SM scores in T1CE and PD-FS showed substantial to almost perfect reproducibility. The parapatellar synovitis score statistically significant correlation with the thickness score in T1CE (r = 0.68) and thee SM scores in T1CE (r = 0.71) and PD-FS (r = 0.66).
The newly proposed quantitative thickness score on T1CE and the semiquantitative SM scores on T1CE and PD-FS can be useful for Hoffa’s fat pad synovitis.
Our findings indicated that the established scoring systems for Hoffa’s fat pad synovitis could be further improved. Future research may propose more reliable methods for Hoffa’s fat pad synovitis.