Table 1.
Characteristics of randomized controlled trials included in the meta-analysis.
| LUS | |||||||||||||||
| Author, year country | Sample size | Boy/Girl | MeanAge (Range) | Study design | Blinding | Patients setting | LUS operator | Ultrasound system | Pneumonia diagnosis | LUS findings | CXR | TP | FP | FN | TN |
| Copetti, 2008, Italy | 79 | 37/42 | 5.1y (6 mo-16 y) | Prospective | Yes | Emergency Department | The samea expert operator | Esaote,convex probe (3.5–5 MHz), linear probe (7.5–10 MHz) | CXR | Consolidations | LUS | 60 | 0 | 0 | 19 |
| CXR | 53 | 0 | 7 | 19 | |||||||||||
| Iuri, 2009, Italy | 28 | 17\11 | 4.5y (4mo-17y) | Prospective | Yes | Paediatric emergency ward | Two radiologists | Philip, convex probe (2–5 MHz) and linear probe (5–12MHz) | CXR | Consolidations | LUS | 22 | 0 | 2 | 4 |
| CXR | 24 | 0 | 0 | 4 | |||||||||||
| Caiulo, 2013, Italy | 102 | 53/49 | 5y (1–16y) | Prospective | Yes | Pediatric department | An expert pediatric sonographer | Sono57500; Philips, Bothell, WA, convex probe (5MHz) | Physical and CXR | Consolidations, FBL, PLA | LUS | 88 | 0 | 1 | 13 |
| CXR | 81 | 0 | 8 | 13 | |||||||||||
| Shah, 2013, American | 200 | 112/88 | 3y (1-8y) | Prospective | Yes | Emergency departments | Trained clinicians | Sonosite, GS60, Siemensa, linear probe (7.5–10MHz) | CXR | Consolidations | LUS | 31 | 18 | 5 | 146 |
| CXR | 36 | 0 | 0 | 164 | |||||||||||
| Hadeel, 2013, Egypt | 75 | 36/39 | 3–26d | Prospective | NO | NICU | The same radiologist | Nemio XG SSA-580A, and a linear 7MHz | CXR | Consolidations | LUS | 68 | 0 | 7 | 0 |
| CXR | 64 | 0 | 11 | 0 | |||||||||||
| Esposito, 2014, Italy | 103 | 56/47 | 5.6y (1mo-14y) | Prospective | Yes | Pediatric ICU | Trained resident paediatrics | MyLab, convex probe (2.5–6.6MHz), linear probe (7.5–12MHz) | Physical and CR | Consolidations | LUS | 47 | 3 | 1 | 52 |
| CXR | 48 | 0 | 0 | 55 | |||||||||||
| Ho, 2014, Taiwan | 163 | 91/72 | 6.1y | Retrospective | Yes | Pediatric ward | Experienced pediatric pulmonologists | Sono57500, Philips, convex probe (5MHz) | BTS guideline | Consolidations, PE, FBL | LUS | 159 | 0 | 4 | 0 |
| CXR | 151 | 0 | 12 | 0 | |||||||||||
| liu, 2014, China | 80 | 43/37 | Newborn | Prospective | Yes | Department of Neonatology & NICU | A single examiner expert physician | GE Voluson E6 or E8, linear probe(9–12 MHz) | Physical and CXR | Consolidations | LUS | 40 | 0 | 0 | 40 |
| CXR | 40 | 0 | 0 | 40 | |||||||||||
| Reali, 2014, Italy | 107 | 61/46 | 4y (0–16y) | Prospective | Yes | Pediatric department | A pulmonologist and two residents | Mylab25; Esaote, Genoa and a linear probe (7.5–10MHz) | Physical and CXR | Consolidations, FBL | LUS | 76 | 1 | 5 | 25 |
| CXR | 66 | 2 | 15 | 24 | |||||||||||
| Iorio, 2015, Italy | 52 | NR | 3.5y (2–12.5y) | Retrospective | Yes | Pediatric ward | The same expert operator | Sonosite, linear probe (5–10MHz) | BTS guideline | Consolidations | LUS | 28 | 1 | 1 | 22 |
| CXR | 25 | 1 | 4 | 22 | |||||||||||
| Dianova, 2015, Russia | 154 | 87/67 | 0–18y | Prospective | Yes | Children's Teaching Hospital | Eperienced radiologist | Hitachi Vision Avius (Japan) and sonoscape s8Exp (China) with 4–11 mHz multifrequency linear probes and 4–11 mHz convex probes | Clinical, CXR, CT | Consolidation, FBL, atelectasis, PE | LUS | 147 | 0 | 7 | 0 |
| CXR | 126 | 0 | 28 | 0 | |||||||||||
| Urbankowska, 2015, Poland | 106 | NR | 52.5mo (1–213mo) | Prospective | Yes | Pediatric ward | The same pediatric sonographer | ALOKA, linear probe (3–7and5–9MH) | Physical and CXR | Consolidations | LUS | 71 | 0 | 5 | 30 |
| CXR | 76 | 0 | 0 | 30 | |||||||||||
| Guerra, 2016, Italy | 222 | 108/114 | 3mo–16y | Prospective | Yes | Paediatric department | Three paediatricians with specific LUS expertise | MyLAB25, Esaote, linear probe (7.5–10MHz), convex probe (3.5–5-MHz) | Clinical characteristis | Consolidations | LUS | 207 | 0 | 7 | 8 |
| CXR | 197 | 0 | 17 | 8 | |||||||||||
| Ianniello, 2016, Italy | 84 | 44/40 | 6y (3–16y) | Retrospective | NO | Emergency department | Professional sonographer | Siemens, convex probe 4MHz and linear probe (7.5–10 MHz) | Clinical, CXR | Consolidations, FBL, PE, air bronchograms | LUS | 60 | 0 | 1 | 23 |
| CXR | 47 | 0 | 14 | 23 | |||||||||||
| Samson, 2016, Spain | 200 | 116/84 | 29.5mo (18.5–52.5mo) | Prospective | Yes | Emergency department | Pediatricians with limited training | Sonosite, linear probe (6–15MHz) | Physical and CXR | Consolidations, PE, alveolar infiltrate | LUS | 74 | 6 | 11 | 109 |
| CXR | 85 | 0 | 0 | 115 | |||||||||||
| Boursiani, 2017, Greece | 69 | 27/42 | 6mo-12y | Prospective | Yes | Emergency department | Eperienced pediatric radiologist | Microconvex probe (5–8MHz), linear probe (5–12MHz), convex (3–5MHz) | clinical criteria and CXR | Consolidations, FBL, atelectasis, PE | LUS | 62 | 0 | 4 | 3 |
| CXR | 63 | 0 | 3 | 3 | |||||||||||
| Man, 2017, Romania | 81 | 42/39 | 6.5y | Retrospective | NO | Emergency department | Senior radiologist experienced | Accuvix V20, convex probe (7–11 MHz) and linear probe (3.5–5 MHz) | CXR | Consolidations | LUS | 57 | 15 | 5 | 4 |
| CXR | 72 | 0 | 0 | 9 | |||||||||||
| Claes, 2017, Belgium | 143 | 77/66 | 41mo (8d–14y) | Prospective | Yes | Emergency room | Basic ultrasound knowledge | Philips iU-22, linear probe (12–5 MHz) | CXR | Consolidations | LUS | 44 | 8 | 1 | 90 |
| CXR | 45 | 0 | 8 | 90 | |||||||||||
| Yilmaz, 2017, Turkey | 160 | NR | 1mo- 18y | Prospective | Yes | Pediatric emergency department | A single trained operator | SonoSite, linear probe (6–13MHz) | BTS guideline | Pleural irregularity, consolidation, FBL, PE, air bronchograms | LUS | 142 | 4 | 7 | 7 |
| CXR | 132 | 0 | 17 | 11 | |||||||||||
| Yadav, 2017, India | 118 | 55/63 | 26.22mo (2–59 mo) | Prospective | Yes | Pediatric emergency department | Trained pulmonary radiologist | GE, LOGIQ P5, microconvex | Physical and CXR | Consolidations, FBL, PLA | LUS | 105 | 0 | 13 | 0 |
| CXR | 101 | 0 | 0 | 17 | |||||||||||
| Iorio, 2018, Italy | 47 | 27/20 | 4y (1mo-12y) | Retrospective | Yes | Pediatric department | A skilled sonographer | Sonosite Micro Maxx Systems ecographic equipment with a 5-to10 MHz linear probe (L38e) | Medical records | Consolidations, PE | LUS | 47 | 0 | 0 | 0 |
| CXR | 38 | 0 | 9 | 0 | |||||||||||
| Lissaman, 2018, Australia | 97 | 47/48 | 1 mo to 18y | Prospective | Yes | Pediatric emergency department | A first-year paediatric emergency medicine fellow with specifical training | A Zonare z.one ultrasound using an L14–5w linear transducer | CXR | Consolidations, FBL, PLA, PE | LUS | 46 | 17 | 4 | 30 |
| CXR | 44 | 0 | 0 | 17 |
BTS = British Thoracic Society, CXR = chest radiography, ED = emergency department, FBL = focal B-lines, FN = false-negative, FP = false-positive, ICU = intensive care unit, LUS = lung ultrasound, NICU = neonatal intensive care unit, PE = pleural effusion, PLA = pleural line abnormality, TN = false-negative, TP = true-positive.