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

Table 1 Magnetic resonance imaging parameters for the sequences

Imaging parameter	Tesla	Sequence
		Sag PD	Sag PD-FS	Sag T1CE	Ax PD-FS	Ax T1CE
Repetition time (ms)	1.5T	2000	3000	438	3400	714
	3T	2054-3940	3000-4150	530-782	3000-5300	530-782
Echo time (ms)	1.5T	46	46	12	43	13
	3T	22-30	30-43	12-20	13-45	12-20
Matrix resolution (mm)	1.5T	0.7 × 0.7	0.7 × 0.7	0.7 × 0.7	0.6 × 0.6	0.6 × 0.6
	3T	0.3 × 3.3	0.3 × 0.3	0.3 × 0.3	0.3 × 0.3	0.3 × 0.3
Field of view (mm)	1.5T	150	150	150	150	150
	3T	150	150	150	150	150
Slice thickness (mm)	1.5T	3.5	3.5	3.5	5	5
	3T	2.5	2.5	2.5	3	3

Sag PD: Sagittal proton density-weighted sequence; Sag PD-FS: Sagittal proton density-weighted fat-suppressed sequence; Sag T1CE: Sagittal contrast-enhanced T1-weighted fat-suppressed sequence; Ax PD-FS: Axial proton density-weighted fat-suppressed sequence; Ax T1CE: Axial contrast-enhanced T1-weighted fat-suppressed sequence; T1CE: T1-weighted fat-suppressed fast spin-echo sequence; PD: Proton density-weighted fast spin-echo sequence; PD-FS: Proton density-weighted fat-suppressed fast spin-echo sequence.

Table 2 Inter and intraobserver reliability

		Intra-observer	Inter-observer
		A1-A2	A1-B	A1-C	B-C
Thickness	T1CE	0.74 (0.65-0.81)	0.69 (0.60-0.77)	0.67 (0.56-0.75)	0.55 (0.42-0.65)
	PD	0.68 (0.58-0.76)	0.45 (0.31-0.57)	0.49 (0.35-0.61)	0.54 (0.41-0.65)
	PD-FS	0.71 (0.61-0.78)	0.59 (0.48-0.69)	0.49 (0.35-0.60)	0.63 (0.52-0.72)
SM score	T1CE	0.88 (0.83-0.91)	0.67 (0.56-0.75)	0.78 (0.70-0.83)	0.56 (0.43-0.66)
	PD	0.88 (0.83-0.91)	0.49 (0.35-0.60)	0.72 (0.63-0.79)	0.50 (0.36-0.61)
	PD-FS	0.89 (0.85-0.92)	0.51 (0.38-0.63)	0.79 (0.71-0.84)	0.62 (0.50-0.71)
MOAKS	T1CE	0.76 (0.68-0.82)	0.64 (0.53-0.73)	0.54 (0.41-0.65)	0.49 (0.35-0.60)
Synovitis-score	T1CE	0.93 (0.91-0.95)	0.65 (0.54-0.74)	0.72 (0.62-0.79)	0.53 (0.40-0.64)
WORMS (effusion synovitis)	PD-FS	0.77 (0.70-0.83)	0.70 (0.61-0.78)	0.61 (0.50-0.71)	0.68 (0.58-0.76)
Effusion-diameter	PD-FS	0.89 (0.85-0.92)	0.77 (0.69-0.83)	0.81 (0.75-0.86)	0.68 (0.58-0.76)

Data are presented as ICC (95%CI). T1CE: T1-weighted fat-suppressed fast spin-echo sequence; PD: Proton density-weighted fast spin-echo sequence; PD-FS: Proton density-weighted fat-suppressed fast spin-echo sequence.

Table 3 Correlation with the MOAKS score

		1.5T	3T	Total
Thickness	T1CE	0.45	0.49	0.47
	PD	0.32	0.49	0.44
	PD-FS	0.42	0.41	0.41
SM score	T1CE	0.55	0.68	0.64
	PD	0.61	0.64	0.63
	PD-FS	0.64	0.74	0.71
Synovitis-score	T1CE	0.68	0.51	0.56
WORMS (effusion synovitis)	PD-FS	0.48	0.55	0.53
Effusion-diameter	PD-FS	0.58	0.48	0.51

All P values are less than 0.01. T1CE: T1-weighted fat-suppressed fast spin-echo sequence; PD: Proton density-weighted fast spin-echo sequence; PD-FS: Proton density-weighted fat-suppressed fast spin-echo sequence.

Table 4 Correlation with the parapatellar synovitis score

		1.5T	3T	Total
Thickness	T1CE	0.63	0.73	0.70
	PD	0.52	0.45	0.47
	PD-FS	0.44	0.51	0.49
SM score	T1CE	0.85	0.79	0.81
	PD	0.42	0.76	0.66
	PD-FS	0.79	0.59	0.65
MOAKS	T1CE	0.66	0.56	0.59
	PD-FS	0.65	0.52	0.56
WORMS (effusion synovitis)	PD-FS	0.64	0.81	0.76
Effusion-diameter	PD-FS	0.52	0.62	0.59

All P values are less than 0.01. T1CE: T1-weighted fat-suppressed fast spin-echo sequence; PD: Proton density-weighted fast spin-echo sequence; PD-FS: Proton density-weighted fat-suppressed fast spin-echo sequence.