Table 4.

Origin of grading system applied to evaluate USI OA features.

Sonographic feature	Origin of grading system (number of studies which applied a grading system)
	Semiquantitative		Dichotomous (present or absent)		Continuous (mm)
	Grading system referenced	Studies that referenced system	Grading system referenced	Studies that referenced system
Osteophytes	4x Mathiessen [27]	[38,42,44,65]	1x Keen [60]	[62]	NR
	2x Keen [60]	[27,63]
	1x Kortekaas [48]	[49]
	1x Hammer [69]	[27]
Erosions	NR	NR	1x Wakefield [80]	[40]	NR
Articular cartilage damage	NR	NR	1x Iagnocco [58]	[65]	NR
Synovitis	5x Keen [60]	[36,38,48,61,63]	1x Hammer [69] 1x Keen [60] 1x Wakefield [80]	[41] [59] [60]	NR
	2x Hammer [69]	[45,68]
	1x Terslev88	[37]
	1x Mandl89	[40]
	1x Mathiessen [27]	[75]
Synovial hypertrophy	5x Kortekaas [48]	[39,46,47,49,52] [43,54] [38,48] [65] [40]	1x Terslev88	[65]	NR
	2x Szkudlarek90
	2x Keen (2008) [60]
	1x D'Agostino91
	1x Mandl89		1x Wakefield [80]	[50]
Joint effusion	5x Kortekaas [48]	[39,46,47,49,52] [54,64] [40] [48]	1x Terslev88	[65]	NR
	2x Szkudlarek90
	1x Mandl89
	1x Keen [60]		1x Wakefield [80]	[50]
Power Doppler activity	5x Kortekaas [48]	[39,46,47,49,52] [36,48,61,63] [42,45] [37] [40] [43] [65]	2x Wakefield [80]	[38,50]	NR
	4x Keen [60]
	2x Hammer [69]1x Terslev88
	1x Mandl89
	1x Szkudlarek90
	1x D'Agostino91		1x Keen [60]	[62]
Joint space narrowing	NR	NR	NR	NR	NR
Tenosynovitis	NR	NR	NR	NR	NR

NR, Not reported.