New scoring system in assessment of Hoffa’s fat pad synovitis: A comparative study with established scoring systems

Figure 1 Thickness score. A: The thickness of Hoffa’s synovitis is measured at three points at the proximal, middle, and distal synovium along the posterior aspect of the Hoffa’s fat pad (yellow arrow); B: Sagittal slices are selected at the medial, lateral, and central patellofemoral groove.

Figure 2 Grading of the Synovial membrane score. A: Grade1 is defined as linear thickening of the posterior Hoffa’s fat pad’s synovium; B: Grade 2 is defined as mild exudation and signal change in the posterior Hoffa’s fat pad; C: Grade 3 is defined as gross nodular thickening of the posterior Hoffa’s fat pad’s synovium.

Figure 3 Parapatellar synovitis score. A: Two slices are chosen for the parapatellar synovitis score, and each corresponds with the first and last axial slice, respectively, in which the patella was still visible; B, C: The five sites of interest include three points in the suprapatellar recess, one point in the lateral gutter, and one point in the medial femoral gutter. Thickening of the inflamed synovium is determined in each site and is graded on a four-point scale, according to the thickness.

Figure 4 A 69-year-old woman with osteoarthritis and a parapatellar score of 9. A: The thickness score is grade 3, the Synovial membrane (SM) score is grade 3, and the MOAKS score is grade 3 on T1-weighted fat-suppressed fast spin-echo sequence; B: The thickness score is grade 2, the SM score is grade 3, and the MOAKS score is grade 3 on proton density-weighted fast spin-echo sequence; C: The thickness score is grade 3, the SM score is grade 3, and the MOAKS score is grade 3 on proton density-weighted fat-suppressed fast spin-echo sequence.

Figure 5 A 71-year-old woman with osteoarthritis and a parapatellar score of 8. A: The thickness score is grade 2, the Synovial membrane (SM) score is grade 3, and the MOAKS score is grade 3 on T1-weighted fat-suppressed fast spin-echo sequence; B: The thickness score is grade 1, the SM score is grade 1, and the MOAKS score is grade 3 on proton density-weighted fast spin-echo sequence; C: The thickness score is grade 2, the SM score is grade 3, and the MOAKS score is grade 3 on proton density-weighted fat-suppressed fast spin-echo sequence.