Table 5 Validity of ultrasonography detected synovial pathology described in the literature including definitions, scoring systems, comparators and results

First author (reference no)	Structure imaged	Definition of imaging appearance of pathology	Scoring system	Comparator	Results
Acebes33	Baker’s cyst	N	Maximal area calculated in two planes using software	Clinical examination	Clinical and ultrasonography parameters decrease after therapy
Acebes33	Synovial hypertrophy	N	Maximal area calculated in two planes using software	Symptoms
Arslan12	Vascular flow (RI)	Y	RI	CT	All osteoarthritis subjects had sacroilitis on CT; however, only 50% had Doppler flow on ultrasonography
Atchia43	Hip joint	DE	DE	N/A	N/A
Baratelli5	Joint capsule thickness	Y	Measured in mm	N/A	N/A
D’Agostino28	Synovial hypertrophy	Y	Present or absent	Clinical examination	Synovitis found more commonly with ultrasonography than CE although there was a strong association between ultrasonography synovitis and clinical effusion
	Effusions	Y	Present or absent	CR	Ultrasonography synovitis associated with KL grade >2
	Effusions	Y	Present or absent	Symptoms	Ultrasonography synovitis was associated with early morning stiffness and sudden aggravation of pain in past 2 weeks
de Miguel Mendieta34	Effusion	Y	Present or absent	Symptoms	Symptomatic knees were more likely to demonstrate effusion and Baker’s cyst than asymptomatic knees
	Bursitis	Y	Present or absent
	Baker’s cyst	Y	Present or absent
Fam3	Popliteal cysts	Y	Present or absent	CR	Ultrasonography found cysts in 29/100 knees
				Arthrogram	Arthrogram used to confirm two cysts
				Symptoms	Ultrasonography popliteal cyst correlated with increasing radiographic grade cysts in 17/36 knees with KL grade >2, but only 12/64 knees with KL grade 2
Giovagnorio17	Vascularity	Y	Present or absent	Clinical examination	GS findings not correlated with laboratory markers or CE
Giovagnorio17	Synovial thickening, effusion.	N	Present or absent	Laboratory biomarkers	PD signal related to ESR
Iagnocco15	Effusion	Y	Measured in mm	Aspiration of fluid	Ultrasonography is able to detect joint effusion
Jan35	Synovial sac thickness	N	Measured in mm	Symptoms	Pain correlated with ultrasonography-detected sac thickness
Jung36	Capsular distension	Y	Measured in mm	Laboratory biomarkers	Subjects with capsular distension and effusion have higher levels of COMP and HA
	Effusion	Y	Measured in mm
	Synovial proliferation	Y	Present or absent
Karim27	Synovitis	Y	4-Point scale (based on morphology)	Clinical examination	Ultrasonography has higher sensitivity and specificity than CE compared with arthroscopy
Karim27	Effusion	Y	Present or absent	Direct visualisation
Keen47	Synovitis	Y	4-Point scale	N/A	N/A
Keen47	Vascularity	Y	4-Point scale (semiquantitative)	N/A	N/A
Kim48	Effusion	Y	Measured in mm	Scintigraphy	Ultrasonography-detected effusion correlated with uptake in medial femoral and tibial condyles
Kim48	Synovitis	Y	U	Scintigraphy
Kristoffersen37	Synovial hypertrophy	Y	NS	Clinical examination	N/A
	Fluid	Y	NS	Symptoms
	Hyperaemia	Y	RI
Lee44	Synovial proliferation	Y	Present or absent	Biochemical markers	Synovial proliferation not associated with biochemical markers
Naredo30	Bursitis	Y	NS	Clinical examination	Ultrasonography effusion was associated with higher VAS pain at rest and on motion
	Effusion	Y	NS	CR
	Popliteal cyst	Y	NS	Symptoms
Ostergaard11	Effusion	Y	Measured in mm	MRI	Ultrasonography detected 100% of effusions, 100% Baker’s cysts, 57% synovial thickening
Ostergaard11	Synovial thickness	Y	Measured in mm	Clinical examination	Ultrasonography and MRI showed moderate correlation with synovial membrane thickness and effusion
Qvistgaard39	Synovial profile	Y	3-Point scale (semiquantitative)	Fluid aspiration	No correlation between fluid aspiration and fluid on ultrasonography
	Effusion	Y	3-Point scale (semiquantitative)
	Global synovitis	N	3-Point scale (semiquantitative)
Robinson45	Effusion	Y	Present or absent	Clinical symptoms	Ultrasonography did not predict clinical response
	Capsular thickness	Y	Measured in mm	Clinical response	Ultrasonography findings did not correlate with symptoms
	Vascularity	N	Present or absent
Schmidt16	Synovial thickness	N	3-Point scale based on measurement in mm	Clinical examination	No agreement between CE and ultrasonography in detecting synovitis
				Direct visualisation	Agreement between GS ultrasonography and arthroscopy as to presence of villi was 80–85%
				Histology	All knees with histological pannus had Doppler signal within hypoehcoic synoial hypertrophy
Song49	Effusion	Y	4-Point scale based on measurement in mm	Clinical examination	Effusion found by ultrasonography in 78%, by MRI 81%
	Synovial hypertrophy	Y	4-Point scale based on measurement in mm	MRI	No correlation between lateral recess effusion and MRI
	Vascularity	N	4-Point scale semiquantitative		Poor correlation between contrast enhancement and MRI
Tarasevicius41	Capsular distension	Y	Measured in mm	N/A	N/A
Tarhan26	Synovial hypertrophy	Y	4-Point scale based on measurement in mm	MRI	Synovial thickening (ultrasonography 34%, MRI 50%)
	Synovial hypertrophy	Y	4-Point scale based on measurement in mm	MRI	Popliteal cysts (ultrasonography 40%, MRI 35%)
	Effusion	Y	4-Point scale based on measurement in mm	Clinical examination	Increased changes with increasing radiographic grade
Walther22	Synovial thickness	N	4-Point scale, based on measurement in mm	Histology	PD valid in detecting vascularity of synovium
	Effusion thickness	Y	4-Point scale, based on measurement in mm
	Vascularity	Y	4-Point scale and software
Walther20	Synovial thickness and effusion	N	4-Point scale, semiquantitative	Histology	Good correlation between PD signal and histological vascularity scores

CE, clinical examination; COMP, cartilage oligomeric matrix protein; CR, conventional radiography; CT, computed tomography; DE, described elsewhere; ESR, erythrocyte sedimentation rate; GS, grey scale; HA, hyaluronic acid; KL, Kellgren Lawrence; MRI, magnetic resonance imaging; N, No; N/A, not applicable; NS, not stated; PD, power Doppler; RI, resistive index; U, unclear; VAS, visual analogue scale; Y, Yes.