Table 2 Overview of included studies

Gargani et al. [23]

33 SSc, including 10 dcSSc, and 23 lcSSc

LUS

HRCT (gold standard)

PFT

72 ScS

Total BN > 10 was defined positive

WS

100%

Intra-observer and inter-observer variability respectively 5.1% and 7.4%

Total BN correlated with WS (r = 0.72; p < 0.001) and DLCO (r = – 0.6, p < 0.05); BN higher in dcSSc than in lcSSc (73 ± 66 vs 21 ± 35; p < 0.05)

N/A

Gutierrez et al. [25]

28 SSc, 2 SS, 2 DM, 2 ASS, 1UCTD, and 1 MCTD

LUS

HRCT (gold standard)

50 ScS (comprehensive method)

14 ScS (simplified method); comprehensive BS was defined 0 = normal (<10 BN); 1 = mild (11–20 BN); 2 = moderate (21–50 BN), and 3 = marked (>50 BN). Simplified BS was defined 0 = normal (<5 BN); 1 = mild (6–15 BN); 2 = moderate (16–30 BN), and 3 = marked (>30 BN)

WS

Simplified method required less time than the comprehensive (8.6 ± 1.4vs 23.3 ± 4.5 minutes, p < 0.001)

κ values for inter-observer reliability of comprehensive method 0.85–0.98.

κ values for inter-observer agreement of simplified method 0.77–0.89 and for intra-observer 0.85–0.89

BS of two methods correlated to WS (p = 0.0006), and simplified score also correlated to comprehensive method (p = 0.0001)

N/A

Barskova et al. [29]

58 SSc, including 32 VEDOSS

LUS

HRCT (gold standard)

72 ScS

BN ≥ 3 was found in at least two adjacent scanning sites or when total BN > 5

100%

Intra-observer and inter-observer variability respectively 5.1% and 7.4%

Total BN significantly higher in SSc + ILD (57 ± 53 vs 9 ± 9, p < 0.0001), and with GGO (63 ± 47 vs 33 ± 40, p < 0.05)

Sensitivity and specificity respectively 100% and 55%; NPV and PPV 100% and 78% respectively

N/A

Tardella et al. [28]

26 SSc, 2 SS, 1 UCTD, 2 ASS, 2 DM, and 1 MCTD

LUS

HRCT (gold standard)

PFT

50 ScS

Grading as comprehensive assessment (Gutierrez et al. [25])

Yes

Overall agreement of inter-observer 92–97%; weighted κ value 0.85–0.98

BS correlated with WS (p < 0.001; CC ρ = 0.875), and DLCO(p = 0.014)

N/A

Moazedi-Fuerst et al. [31]

25 SSc and 40 healthy controls

LUS

HRCT (only for patients)

18 ScS

Positive area for B lines = ScS with predominant B lines; positive area for PI = predominant PLT > 2.8 mm

BS: 0 = no positive areas; 1 = 1–5 positive areas; 2 = > 5 positive areas. Idem for PI

N/A

N/A

SSc + ILD had a BS of 2 in 55% and 1 in 45%; SSc – ILD had a BS of 2 in 5% and BS of 1 in 30%; SSc + ILD had a PI of 2 in 23% and 1 in 78%; SSc – ILD had a negative PI

N/A

Pinal Fernández et al. [38]

21 ASS

LUS

HRCT (gold standard)

72 ScS

Percentage of positive B-lines calculated (dividing the positive points by studied points)

WS

N/A

κ value of intra-observer and inter-observer 0.83 and 0.76

BS no correlated with WS (CC = 0.135, p = 0.559); BS correlated with GGO (ρ = 0.502, p = 0.02)

N/A

Cogliati et al. [36]

39 RA

LUS (standard and PS-USD)

HRCT (gold standard)

PFT

72 ScS

BN > 10 identified positive

WS

Yes

r-value for inter-observer variability 0.96; κ coefficient of two devices 0.78

BS correlated with WS (r = 0.806). Sensitivity and specificity of standard LUS vs HRCT 92% and 56%, and PS-USD vs HRCT 89% and 50%

N/A

Moazedi-Fuerst et al. [35]

64 RA and 40 healthy controls

LUS

HRCT (gold standard, only for patients)

18 ScS

Grading as previous report (2012)

Yes

κ value of inter-observer 0.92

Sensitivity and specificity of LUS respectively 97.1% and 97.3%; PPV and NPV 94.3% and 98.6% respectively (p < 0.001)

N/A

Mohammadi et al. [26]

70 SSc

LUS (modified TTUS)

HRCT (gold standard)

10 ScS

BS: 0 = normal (≤5 BN); 1 = mild (6–15 BN); 2 = moderate (16–30 BN); 3 = severe (>30 BN)

WS

Yes

κ value of intra-observer reliability 0.838.

Agreement between LUS and HRCT 0.553 (p < 0.001)

BS correlated with WS (SCC = 0.695, p < 0.001); sensitivity and specificity respectively 73.5% and 88.23%; PPV and NPV 95.12% and 51.72% respectively

N/A

Gigante et al. [24]

39 SSc, including 24 dcSSc and 15 lcSSc

LUS

HRCT (gold standard)

PFT

NVC

BN ≥ 3 was found in at least two adjacent scanning sites or when a total BN > 5

WS

N/A

Intra-observer variability 3.8%

BN correlated with WS (r = 0.81, p < 0.0001), DLCO (r = – 0.63, p < 0.0001), and DSS (r = 0.8, p < 0.01)

N/A

Moazedi-Fuerst et al. [33]

25 RA, 14 SSc, 6 SLE, and 40 healthy controls

LUS

HRCT (gold standard, only for patients)

18 ScS

BN > 2 and PLT > 3 mm in any scanned area regarded as abnormal. Grading as previous report (2012)

Yes

N/A

Sensitivity and specificity of LUS respectively 86.9% and 100%; PPV and NPV 100% and 88% respectively

N/A

Pinal-Fernandez et al. [32]

16 SSc and 21 ASS

LUS

HRCT (gold standard)

PFT

72 ScS

Percentage of positive BN and PI calculated (dividing the positive points by studied points)

WS and Wells scores

N/A

N/A

PI correlated with WS both in SSc (r = 0.6, p = 0.01) and ASS (r = 0.6, p = 0.005), higher performance than BS (p = 0.01). PI also correlated with Wells score (r = 0.7, p < 0.001) and with DLCO (r = – 0.5, p = 0.05) in SSc, and high diagnostic value for detecting ILD (AUC = 0.85, 95% CI 0.64–1) and classified limited and extensive (AUC = 0.81, 95% CI 0.57–1)

N/A

Buda et al. [30]

52 ILD (including 30 CTD and 16 IP) and

50 healthy controls

LUS

HRCT (gold standard)

BN classified into three types: single (≤3 per one scan), numerous (≥4), and white lung. PI was described ragged, fragmentary, thickness (≥2 mm), and blurred

WS

N/A

N/A

Sensitivity and specificity of white lung to GGO.95% and 99%; blurred pleural line to honeycombing 59% and 82% (p < 0.005); numerous B lines correlated with blurred pleural line (p<0.001)

N/A

Sperandeo et al. [34]

175 SSc

LUS

HRCT (gold standard)

BN > 3; PLT > 3.0 mm; HRCT pattern classified: no fibrosis, reticular, reticular-nodular, and honeycombing + reticular-nodular pattern

N/A

κ value of inter-observer and intra-observer 0.6–0.8

Sensitivity and specificity of PLT (>3.0 to ≤ 5.0) to reticular pattern 80% and 99% (AUC = 0.95); PLT (>3.5) to reticular nodular and honeycombing 74.3% and 99% (AUC = 0.99); PLT (>5) to honeycombing 90.1% and 99% (AUC = 0.99)

Sensitivity and specificity of BS to all kinds of fibrosis 0.94 and 0.95

N/A

Vasco et al. [37]

13 SS

LUS

HRCT (gold standard)

8ScS BN ≥ 3 in a single ScS

N/A

κ value of intra-rater 1

BS correlated with HRCT (r = 0.84, p < 0.001); sensitivity and specificity respectively 100% and 89%

N/A