Skip to main content
NCBI home page
Italian Journal of Pediatrics logoLink to Italian Journal of Pediatrics
. 2024 Jan 23;50:12. doi: 10.1186/s13052-024-01583-3

Comparison of lung ultrasound and chest radiography for detecting pneumonia in children: a systematic review and meta-analysis

Yalong Yang 1,✉, Yuexuan Wu 1, Wen Zhao 2
PMCID: PMC10804756  PMID: 38263086

Abstract

Background

Lung ultrasound (LUS) is recommended as a reliable diagnostic alternative to chest X-ray (CXR) for detecting pneumonia in children.

Methods

PubMed, Embase, and Cochrane Library databases were used to identify eligible studies from their inception until April 2023. The investigated diagnostic parameters included sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the receiver operating characteristic curves (AUC).

Results

Twenty-six studies involving 3,401 children were selected for meta-analysis. The sensitivity, specificity, PLR, NLR, DOR, and AUC of LUS for detecting pneumonia in children were 0.95, 0.92, 12.31, 0.05, 108.53, and 0.98, respectively, while the sensitivity, specificity, PLR, NLR, DOR, and AUC of CXR were 0.92, 0.93, 24.63, 0.08, 488.54, and 0.99, respectively. The sensitivity of LUS was higher than that of CXR for detecting pneumonia in children (ratio: 1.03; 95% CI: 1.01–1.06; P = 0.018), whereas the DOR of LUS was significantly lower than that of CXR (ratio: 0.22; 95% CI: 0.06–0.85; P = 0.028).

Conclusions

This study found that the diagnostic performance of LUS was comparable to that of CXR for detecting pneumonia, and the sensitivity of LUS was superior to that of CXR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-024-01583-3.

Keywords: Lung ultrasound, Chest X-ray, Pneumonia, Children, Meta-analysis

Background

Pneumonia is the main cause of hospitalization and the leading cause of death in children aged < 5 years worldwide [1]. Early diagnosis and timely treatment are important for reducing morbidity and mortality [2]. The symptoms of pneumonia are non-specific in children, and there is no single test with a high sensitivity and specificity for diagnosing pneumonia. Clinicians diagnose pneumonia in children in resource-limited settings using the World Health Organization criteria; however, the sensitivity and specificity are low, which results in misdiagnosis and overtreatment [3, 4]. Chest computed tomography is regarded as the gold standard for detecting pneumonia; however, its routine use is restricted by cost, accessibility, and radiation exposure [5].

In clinical practice, chest radiography (CXR) is a widely used imaging modality for diagnosing pneumonia [6]. However, the routine use of CXR is restricted by some diagnostic and technical limitations, including the absence of definitive diagnostic criteria and intra- and inter-observer variations [7–9]. Moreover, exposure to ionizing radiation in children could increase the risk of cancer later in life [6, 10, 11]. Lung ultrasound (LUS) is radiation-free, portable, and inexpensive, which can be conducted at the point of care. Furthermore, the portable ultrasonography machines was easier obtained, which raises the potential of LUS for diagnostic methods in remote settings. It could identify complications of pneumonia and is widely used for the diagnosis and management of pneumonia in children [12, 13]. However, whether the diagnostic performance of LUS and CXR for pneumonia in children is comparable remains unclear. Therefore, the current systematic review and meta-analysis was performed to compare the diagnostic performance of LUS with that of CXR in detecting pneumonia in children.

Methods

Data collection

This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement [14]. The study protocol was registered at the INPLASY register (INPLASY202340071). We searched for studies that presented the diagnostic value of LUS with CXR for diagnosing pneumonia in children, and no restrictions were placed on publication language and status. We systematically searched PubMed, EmBase, and the Cochrane Library to screen eligible studies throughout April 2023, and used ((“pneumonia” [MeSH Terms] OR “pneumonia” [All Fields]) AND (“ultrasound” [MeSH Terms] OR (“ultrasound” [All Fields]) as search terms. The search terms were restricted to “Child: birth-18 years.” We also manually reviewed relevant reference lists, citation searches, and systematic reviews to identify any new eligible studies.

The processes of literature search and study selection were independently performed by two reviewers, and any disagreement between reviewers was resolved by discussion with an additional reviewer. Study was included if they met: (1) participants: all of individuals aged < 18.0 years, and suspected for pneumonia; (2) diagnostic tools: the study had to applied both LUS and CXR as diagnostic tools; (3) gold standard: the gold standard for diagnosing pneumonia should clear report; (4) outcomes: studies reported true positive, false positive, false negative, true negative, or data could be transformed into such; and (5) study design: no restrictions placed on study design, including prospective and retrospective design.

Data collection and quality assessment

The following variables were independently collected by two reviewers: first author’s name, publication year, country, study design, sample size, number of boys/girls, mean age, setting, pneumonia diagnosis, diagnostic tool, true positive, false positive, false negative, and true negative data. Then, the methodological quality was assessed by the quality assessment of diagnostic accuracy studies-2 (QUADAS-2), which was based on patient selection, index tests, reference standard, and flow and timing; the categories low risk, high risk, and unclear were assigned to each study [15]. Inconsistent results regarding data collection and quality assessment between reviewers were resolved by a third reviewer.

Statistical analysis

The diagnostic parameters of LUS and CXR were analyzed using true positive, false positive, false negative, and true negative data with a bivariate generalized linear mixed model and a the random-effects model. The calculated outcomes included sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the receiver operating characteristic curves (AUC) [16, 17]. The heterogeneity among studies was evaluated using the I2 and Q statistics, and I2 ≥ 50.0% or P < 0.10 was defined as significant heterogeneity [18, 19]. Then, the ratio of sensitivity, specificity, PLR, NLR, DOR, and AUC between LUS and CXR were compared using the random-effects model [16, 17, 20]. Subsequently, subgroup analyses were performed based on country, study design, mean age, and gold standards. A funnel plot with Deeks’ asymmetry test was applied to assess potential publication bias [21]. All reported P were 2-sided, and the inspection level for pooled conclusions was 0.05. STATA software (version 12.0 StataCorp, Texas, USA) was used to perform all statistical analyses.

Results

Literature search

An initial electronic search yielded 1,315 records, and 943 studies were retained after removing duplicate studies. After the title and abstract were reviewed for relevance, 871 studies were removed. The remaining 72 studies were retrieved for detailed evaluations, and 46 studies were excluded because of other diseases (n = 31), no CXR data (n = 12), and no desirable data (n = 3). A total of seven articles were identified by manually reviewing the reference lists of relevant articles, and all of these studies were removed owing to duplicate articles. Subsequently, 26 studies were selected for quantitative meta-analysis [22–47]. The literature search and study selection process are shown in Fig. 1.

Fig. 1.

Fig. 1

Open in a new tab

The processes of literature search and study selection

Study characteristics

Table 1 summarizes the baseline characteristics of the included studies and patients. Of the included studies, 22 studies were prospective, and four studies were retrospective. These studies involved 3,401 children, and the sample size ranged from 28 to 641. The mean age of the included children ranged from newborn to 6.5 years. Twenty-one studies were performed in Western countries, and five studies were conducted in Eastern countries. Sixteen studies used clinical criteria to diagnose pneumonia, and the remaining 10 studies used CXR to diagnose pneumonia. The methodological quality of the included studies is shown in Table S1, and the overall quality of the included studies was moderate to high.

Table 1.

The baseline characteristics of included studies

Study Region Study design Sample size Boy/girl Age (years) Setting Pneumonia diagnosis Diagnostic tool TP FP FN TN
Copetti 2008 [22] Italy Prospective 79 37/42 5.1 Emergency department CXR LUS 60 0 0 19
CXR 53 0 7 19
Iuri 2009 [23] Italy Prospective 28 17/11 4.5 Pediatric emergency ward CXR LUS 22 0 2 4
CXR 24 0 0 4
Shah 2013 [24] USA Prospective 200 112/88 3.0 Emergency departments CXR LUS 31 18 5 146
CXR 36 0 0 164
Caiulo 2013 [25] Italy Prospective 102 53/49 5.0 Pediatric departments Physical and CXR LUS 88 0 1 13
CXR 81 0 8 13
Seif 2013 [26] Egypt Prospective 75 36/39 Newborn Neonatal ICU CXR LUS 64 4 7 0
CXR 64 0 11 0
Esposito 2014 [27] Italy Prospective 103 56/47 5.6 Pediatric ICU Physical and CXR LUS 47 3 1 52
CXR 48 0 0 55
Liu 2014 [28] China Prospective 80 43/37 Newborn Neonatal ICU Physical and CXR LUS 40 0 0 40
CXR 40 0 0 40
Reali 2014 [29] Italy Prospective 107 61/46 4.0 Pediatric departments Physical and CXR LUS 76 1 5 25
CXR 66 2 15 24
Iorio 2015 [30] Italy Retrospective 52 NA 3.5 Pediatric ward BTS guideline LUS 28 1 1 22
CXR 25 1 4 22
Urbankowska 2015 [31] Poland Prospective 106 NA 4.4 Pediatric ward Physical and CXR LUS 71 0 5 30
CXR 76 0 0 30
Ho 2015 [32] China Retrospective 163 91/72 6.1 Pediatric ward BTS guideline LUS 147 12 4 0
CXR 151 0 12 0
Ianniello 2016 [33] Italy Retrospective 84 44/40 6.0 Emergency departments Physical and CXR LUS 60 0 1 23
CXR 47 0 14 23
Guerra 2016 [34] Italy Prospective 222 108/114 4.9 Pediatric departments Clinical diagnosed LUS 207 0 7 8
CXR 197 0 17 8
Boursiani 2017 [35] Greece Prospective 69 27/42 4.5 Emergency departments Clinical and CXR LUS 62 0 4 3
CXR 63 0 3 3
Man 2017 [36] Romania Retrospective 81 42/39 6.5 Emergency departments CXR LUS 57 15 5 4
CXR 72 0 0 9
Yadav 2017 [37] India Prospective 118 55/63 2.2 Emergency departments Physical and CXR LUS 99 6 2 11
CXR 101 0 0 17
Yilmaz 2017 [38] Turkey Prospective 160 NA 3.3 Emergency departments BTS guideline LUS 142 4 7 7
CXR 132 0 17 11
Claes 2017 [39] Belgium Prospective 143 77/66 3.4 Emergency departments CXR LUS 44 8 1 90
CXR 45 0 8 90
Samson 2018 [40] Spain Prospective 200 116/84 2.5 Emergency departments Physical and CXR LUS 74 6 11 109
CXR 85 0 0 115
Zhan 2018 [41] Denmark Prospective 82 47/35 1.5 Pediatric departments CXR LUS 33 7 49 75
CXR 41 0 0 41
Biagi 2018 [42] Italy Prospective 87 43/44 5.8 Pediatric departments Physical and CXR LUS 25 10 0 52
CXR 24 8 1 54
Lissaman 2019 [43] Australia Prospective 97 47/50 2.4 Emergency departments CXR LUS 46 17 4 30
CXR 44 0 0 17
Bloise 2021 [44] Italy Prospective 68 38/30 4.9 Pediatric ward CXR LUS 40 1 1 26
CXR 40 1 1 26
Zhu 2022 [45] China Prospective 60 NA Newborn Pediatric ward Physical and CXR LUS 29 2 1 28
CXR 28 0 1 1
Don 2022 [46] Italy Prospective 641 NA < 16.0 Pediatric departments CXR LUS 575 14 26 26
CXR 533 5 68 35
Guitart 2022 [47] Spain Prospective 194 81/113 0.4 Pediatric ICU BTS guideline LUS 76 2 21 95
CXR 82 46 15 51
Open in a new tab

Sensitivity and specificity

The summary sensitivity and specificity of LUS for detecting pneumonia in children were 0.95 (95% CI: 0.93–0.97), and 0.92 (95% CI: 0.81–0.97), while the sensitivity and specificity of CXR were 0.92 (95% CI: 0.90–0.93), and 0.93 (95% CI: 0.91–0.95), respectively (Fig. 2). We noted that the sensitivity of LUS was higher than that of CXR for detecting pneumonia in children (ratio: 1.03; 95% CI: 1.01–1.06; P = 0.018), whereas there was no significant difference between LUS and CXR for specificity (ratio: 0.99; 95% CI: 0.90–1.09; P = 0.819). Subgroup analyses found that LUS was associated with a higher sensitivity than CXR in most subgroups, whereas no significant difference was observed between LUS and CXR for sensitivity if pooled studies were conducted in Eastern countries, had a mean age < 5.0 years, and used CXR diagnosed pneumonia (Table 2). Moreover, there were no significant differences in specificity between LUS and CXR in all subgroups (Table 2).

Fig. 2.

Fig. 2

Open in a new tab

The summary sensitivity and specificity of LUS for detecting pneumonia

Table 2.

Subgroup analyses for diagnostic performance of US and chest radiography

Parameters Factors Subgroups US Chest radiography US vs. chest radiography P value
Sensitivity Country Eastern 0.97 (0.95–0.98) 0.94 (0.91–0.97) 1.03 (1.00-1.07) 0.083
Western 0.95 (0.91–0.97) 0.91 (0.90–0.93) 1.04 (1.01–1.08) 0.019
Study design Prospective 0.95 (0.92–0.97) 0.92 (0.91–0.93) 1.03 (1.00-1.06) 0.028
Retrospective 0.97 (0.93–0.98) 0.89 (0.83–0.93) 1.09 (1.02–1.16) 0.007
Age (years) ≥ 5.0 0.98 (0.95–0.99) 0.92 (0.88–0.94) 1.07 (1.02–1.11) 0.001
< 5.0 0.94 (0.90–0.96) 0.92 (0.90–0.93) 1.02 (0.99–1.06) 0.244
Gold standard CXR 0.93 (0.85–0.97) 0.91 (0.89–0.93) 1.02 (0.95–1.10) 0.540
Clinical diagnosed 0.96 (0.94–0.98) 0.92 (0.90–0.93) 1.04 (1.02–1.07) 0.002
Overall - 0.95 (0.93–0.97) 0.92 (0.90–0.93) 1.03 (1.01–1.06) 0.018
Specificity Country Eastern 0.76 (0.10–0.99) 1.00 (0.95-1.00) 0.76 (0.24–2.40) 0.644
Western 0.94 (0.84–0.98) 0.93 (0.91–0.94) 1.01 (0.93–1.09) 0.790
Study design Prospective 0.93 (0.85–0.97) 0.93 (0.91–0.95) 1.00 (0.93–1.07) 1.000
Retrospective 0.70 (0.01-1.00) 0.98 (0.90-1.00) 0.71 (0.07–7.15) 0.775
Age (years) ≥ 5.0 0.94 (0.24-1.00) 0.96 (0.91–0.98) 0.98 (0.48-2.00) 0.954
< 5.0 0.92 (0.83–0.96) 0.93 (0.91–0.94) 0.99 (0.92–1.07) 0.776
Gold standard CXR 0.83 (0.55–0.95) 0.99 (0.97–0.99) 0.84 (0.64–1.10) 0.212
Clinical diagnosed 0.95 (0.84–0.99) 0.89 (0.86–0.92) 1.07 (0.98–1.17) 0.150
Overall - 0.92 (0.81–0.97) 0.93 (0.91–0.95) 0.99 (0.90–1.09) 0.819
PLR Country Eastern 4.05 (0.33–50.33) 19.70 (4.85–79.94) 0.21 (0.01–3.65) 0.281
Western 15.06 (5.82–38.97) 25.30 (8.07–79.29) 0.60 (0.13–2.63) 0.494
Study design Prospective 13.40 (6.28–28.60) 24.77 (7.98–76.94) 0.54 (0.14–2.11) 0.377
Retrospective 3.22 (0.08-130.92) 23.08 (5.92–89.99) 0.14 (0.00-7.19) 0.327
Age (years) ≥ 5.0 16.22 (0.41-634.34) 23.03 (5.84–90.71) 0.70 (0.01–35.49) 0.861
< 5.0 11.77 (5.39–25.68) 24.67 (6.15–99.03) 0.48 (0.10–2.35) 0.363
Gold standard CXR 5.43 (1.74–16.87) 29.37 (10.82–79.73) 0.18 (0.04–0.84) 0.029
Clinical diagnosed 20.79 (5.64–76.64) 19.86 (5.08–77.58) 1.05 (0.16–6.91) 0.962
Overall - 12.31 (4.70-32.23) 24.63 (8.63–70.26) 0.50 (0.12–2.07) 0.340
NLR Country Eastern 0.04 (0.01–0.11) 0.03 (0.00-0.45) 1.33 (0.08–21.44) 0.839
Western 0.06 (0.03–0.10) 0.09 (0.06–0.13) 0.67 (0.33–1.36) 0.267
Study design Prospective 0.05 (0.03–0.09) 0.07 (0.05–0.11) 0.71 (0.36–1.40) 0.329
Retrospective 0.05 (0.01–0.31) 0.12 (0.04–0.40) 0.42 (0.05–3.29) 0.407
Age (years) ≥ 5.0 0.02 (0.01–0.05) 0.08 (0.03–0.20) 0.25 (0.07–0.87) 0.029
< 5.0 0.07 (0.04–0.12) 0.08 (0.05–0.12) 0.88 (0.43–1.77) 0.709
Gold standard CXR 0.08 (0.03–0.21) 0.06 (0.02–0.12) 1.33 (0.36-5.00) 0.670
Clinical diagnosed 0.04 (0.02–0.07) 0.09 (0.05–0.15) 0.44 (0.19–1.02) 0.056
Overall - 0.05 (0.03–0.08) 0.08 (0.05–0.12) 0.63 (0.32–1.21) 0.161
DOR Country Eastern 81.92 (11.48-584.54) 667.85 (63.42-7032.51) 0.12 (0.01–2.63) 0.180
Western 117.11 (50.77-270.15) 456.63 (136.86-1523.53) 0.26 (0.06–1.11) 0.069
Study design Prospective 125.88 (60.27–262.90) 531.40 (155.82-1812.26) 0.24 (0.06–0.99) 0.049
Retrospective 41.35 (1.21-1415.91) 234.68 (46.36-1187.99) 0.18 (0.00-8.59) 0.381
Age (years) ≥ 5.0 169.74 (12.07-2386.56) 359.58 (109.34-1182.51) 0.47 (0.03–8.57) 0.612
< 5.0 96.89 (46.24-203.02) 497.45 (131.40-1883.28) 0.19 (0.04–0.89) 0.035
Gold standard CXR 36.90 (12.49-109.05) 904.64 (179.00-4572.05) 0.04 (0.01–0.29) 0.001
Clinical diagnosed 212.69 (97.44-464.25) 344.23 (76.84-1542.09) 0.62 (0.11–3.35) 0.577
Overall - 108.53 (51.30-229.61) 488.54 (160.82-1484.16) 0.22 (0.06–0.85) 0.028
AUC Country Eastern 0.97 (0.95–0.98) 0.99 (0.97-1.00) 0.98 (0.96-1.00) 0.066
Western 0.98 (0.96–0.99) 0.99 (0.98-1.00) 0.99 (0.97–1.01) 0.280
Study design Prospective 0.98 (0.97–0.99) 0.99 (0.98-1.00) 0.99 (0.98-1.00) 0.166
Retrospective 0.97 (0.95–0.98) 0.99 (0.97-1.00) 0.98 (0.96-1.00) 0.066
Age (years) ≥ 5.0 0.99 (0.97–0.99) 0.99 (0.98-1.00) 1.00 (0.98–1.01) 0.803
< 5.0 0.97 (0.96–0.98) 0.99 (0.98-1.00) 0.98 (0.97–0.99) 0.006
Gold standard CXR 0.96 (0.93–0.97) 0.99 (0.99-1.00) 0.97 (0.95–0.99) 0.004
Clinical diagnosed 0.98 (0.97–0.99) 0.98 (0.96-1.00) 1.00 (0.98–1.02) 1.000
Overall - 0.98 (0.96–0.99) 0.99 (0.98-1.00) 0.99 (0.97–1.01) 0.280
Open in a new tab

PLR and NLR

The summary PLR and NLR of LUS for detecting pneumonia were 12.31 (95% CI: 4.70-32.23), and 0.05 (95% CI: 0.03–0.08), while the PLR and NLR of CXR for diagnosing pneumonia were 24.63 (95% CI: 8.63–70.26), and 0.08 (95% CI: 0.05–0.12), respectively (Figure S1). There were no significant differences between LUS and CXR for PLR (ratio: 0.50; 95% CI: 0.12–2.07; P = 0.340) and NLR (ratio: 0.63; 95% CI: 0.32–1.21; P = 0.161). Subgroup analyses found that LUS was associated with a lower PLR than CXR if pooled studies used CXR as the gold standard. Moreover, LUS was associated with a lower NLR than CXR if the mean age of the children was ≥ 5.0 years (Table 2).

DOR

We noted that the summary DOR of LUS for detecting pneumonia was 108.53 (95% CI: 51.30-229.61), while the DOR of CXR for diagnosing pneumonia was 488.54 (95% CI: 160.82-1484.16) (Figure S2). The comparison results indicated that the DOR of LUS for detecting pneumonia was lower than that of CXR (ratio: 0.22; 95% CI: 0.06–0.85; P = 0.028). Subgroup analyses indicated that LUS was associated with a lower DOR as compared with CXR when pooled prospective studies, the mean age of children was < 5.0 years, and CXR was used as the gold standard to diagnose pneumonia (Table 2).

AUC

The AUC of LUS for detecting pneumonia in children was 0.98 (95% CI: 0.96–0.99), while the AUC of CXR for diagnosing pneumonia in children was 0.99 (95% CI: 0.98-1.00) (Fig. 3). There was no significant difference between LUS and CXR for AUC (ratio: 0.99; 95% CI: 0.97–1.01; P = 0.280). Subgroup analyses found that LUS was associated with a lower AUC than CXR when the mean age of children was < 5.0 years, and CXR was applied as the gold standard to diagnose pneumonia (Table 2).

Fig. 3.

Fig. 3

Open in a new tab

The area under the receiver operating characteristic curves of LUS for detecting pneumonia

Publication bias

The publication bias of LUS for detecting pneumonia in children is shown in Figure S3, and the Deeks’ asymmetry test suggested no significant publication bias (P = 0.78).

Discussion

Our study found that the diagnostic values of LUS and CXR were relatively good for detecting pneumonia in children. Moreover, we noted that LUS was associated with a higher sensitivity and lower DOR for detecting pneumonia than CXR. However, we did not find any differences between LUS and CXR for specificity, PLR, NLR, and AUC. Finally, the diagnostic performance between LUS and CXR could be affected by study design, mean age of children, and gold standard for diagnosing pneumonia.

The diagnostic performance of LUS has been investigated in several systematic reviews and meta-analyses [13, 48–51]. Orso et al. identified 17 studies and found that the diagnostic performance of LUS was relatively higher, although these results were restricted by reliable reference standard [48]. Tsou et al. identified 25 studies and found that LUS could accurately detect pneumonia in children, and the performance of LUS could be affected by experienced sonographers [49]. Pereda et al. identified five studies and found that LUS could be considered an imaging alternative for detecting pneumonia in children; however, this conclusion was restricted by unstable results [13]. Xin et al. identified eight studies and supports using LUS for detecting pneumonia in children, and the most common clinical signs of LUS were pulmonary consolidation, positive air bronchogram, abnormal pleural line, and pleural effusion [50]. However, these studies only provided a summary of the diagnostic performance of LUS for detecting pneumonia in children, and the diagnostic value between LUS and CXR was not directly compared [13, 48–50]. Most recently, a meta-analysis conducted by Yan et al. identified 22 studies and suggested that LUS could be regarded as a reliable, valuable, and alternative diagnostic tool to CXR for detecting pneumonia in children [51]. However, this study had several shortcomings, including mistakes on data abstraction, an absence of direct comparison results, and no investigation on the diagnostic performance of LUS versus CXR in study or children with specific characteristics.

Our study found that the diagnostic performance of LUS was relatively high for detecting pneumonia in children, which was consistent with prior meta-analyses [13, 48–51]. We also noted that the diagnostic performance of LUS and CXR for detecting pneumonia in children was comparable. Furthermore, the sensitivity of LUS was higher than that of CXR, which suggests that LUS could differentiate more pneumonia cases, and the prognosis of pneumonia in children could improve. Although CXR is inexpensive and quick, it has a poor ability to distinguish alveolar and interstitial pneumonia. Additional shortcomings of CXR include ionizing radiation and inter-observer agreement [52–54]. The use of LUS can monitor disease progression without exposure to ionizing radiation. Studies have already demonstrated that the use of LUS could shorten emergency department stays, lower financial costs, and reduce complications related to invasive procedures [55–57].

Subgroup analyses found that the diagnostic performance of LUS and CXR for detecting pneumonia in children could be affected by study design, mean age of children, and the gold standard used for diagnosing pneumonia. Several reasons could explain these results: (1) the study design is significantly related to intrinsic biases, and inevitable limitations for retrospective studies include selection and recall biases. Moreover, most included studies were designed as prospective; thus, the pooled conclusions based on retrospective studies were not stable; (2) the diagnostic performance of LUS in children was higher than that in adults for detecting pneumonia [50, 58]. Our study found that LUS was superior to CXR for children aged 5.0 years or older, while the diagnostic performance of LUS was lower than CXR for children aged less than 5.0 years; and (3) numerous included studies applied CXR as the gold standard for detecting pneumonia, and the diagnostic value of CXR may have been overestimated.

This study had some limitations. First, the analysis was based on prospective and retrospective studies, and the pooled conclusions could be affected by uncontrolled selection, recall, and confounding biases. Second, the sonographer’s experience could have affected the diagnostic performance of LUS. Third, the gold standard for diagnosing pneumonia varies across the included studies, which could affect the diagnostic value of LUS and CXR. Fourth, the severity of pneumonia differed across the included studies, which could have affected the complexity of detecting pneumonia in children. Finally, the inherent limitations of meta-analyses based on published data include inevitable publication bias and restricted detailed analyses.

Conclusions

Both LUS and CXR showed high diagnostic performance in detecting pneumonia in children, and the diagnostic parameters were comparable in terms of specificity, PLR, NLR, and AUC. Moreover, we noted that LUS was associated with higher sensitivity and lower DOR for detecting pneumonia in children than CXR. Exploratory analyses found the diagnostic value of LUS were lower than CXR for detecting pneumonia in children less than 5.0 years. Thus, the LUS should be recommended for detecting pneumonia in older children. Further large-scale prospective studies should be performed to compare the diagnostic value of LUS with CXR for detecting pneumonia in children with specific characteristics.

Supplementary Information

13052_2024_1583_MOESM1_ESM.docx (15KB, docx)

Additional file 1: Table S1. The methodological quality of included studies.

13052_2024_1583_MOESM2_ESM.eps (996.3KB, eps)

Additional file 2: Figure S1. The summary PLR and NLR of LUS for detecting pneumonia.

13052_2024_1583_MOESM3_ESM.eps (1.1MB, eps)

Additional file 3: Figure S2. The summary DOR of LUS for detecting pneumonia.

13052_2024_1583_MOESM4_ESM.eps (490.4KB, eps)

Additional file 4: Figure S3. The publication bias of LUS for detecting pneumonia.

Acknowledgements

Not applicable.

Abbreviations

LUS

Lung ultrasound

CXR

Chest X-ray

PLR

Positive likelihood ratio

NLR

Negative likelihood ratio

DOR

Diagnostic odds ratio

AUC

A

rea under the receiver operating characteristic curves

Authors’ contributions

YLY carried out the studies, participated in collecting data, and drafted the manuscript. YXW performed the statistical analysis and participated in its design. WZ helped to draft the manuscript. All authors read and approved the final manuscript.

Funding

None.

Availability of data and materials

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Footnotes

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

  • 1.Organization WH. April : Children: improving survival and well-being [updated September 2020]. Available from: https://www.who.int/news-room/fact-sheets/detail/children-reducing-mortality. Accessed 2023.
  • 2.Mortensen EM, Restrepo MI, Anzueto A, Pugh JA. Antibiotic therapy and 48-hour mortality for patients with pneumonia. Am J Med. 2006;119(10):859–64. doi: 10.1016/j.amjmed.2006.04.017. [DOI] [PubMed] [Google Scholar]
  • 3.House DR, Rijal S, Adhikari S, Cooper ML, Hohl CM. Prospective evaluation of World Health Organization guidelines for diagnosis of pneumonia in children presenting to an emergency department in a resource-limited setting. Paediatr Int Child Health. 2020;40(4):227–30. doi: 10.1080/20469047.2020.1815483. [DOI] [PubMed] [Google Scholar]
  • 4.Chavez MA, Naithani N, Gilman RH, Tielsch JM, Khatry S, Ellington LE, Miranda JJ, Gurung G, Rodriguez S, Checkley W. Agreement between the World Health Organization Algorithm and Lung consolidation identified using point-of-care Ultrasound for the diagnosis of Childhood Pneumonia by General practitioners. Lung. 2015;193(4):531–8. doi: 10.1007/s00408-015-9730-x. [DOI] [PubMed] [Google Scholar]
  • 5.Donnelly LF, Klosterman LA. The yield of CT of children who have complicated pneumonia and noncontributory chest radiography. AJR Am J Roentgenol. 1998;170(6):1627–31. doi: 10.2214/ajr.170.6.9609186. [DOI] [PubMed] [Google Scholar]
  • 6.Cherian T, Mulholland EK, Carlin JB, Ostensen H, Amin R, de Campo M, Greenberg D, Lagos R, Lucero M, Madhi SA, et al. Standardized interpretation of paediatric chest radiographs for the diagnosis of pneumonia in epidemiological studies. Bull World Health Organ. 2005;83(5):353–9. [PMC free article] [PubMed] [Google Scholar]
  • 7.Bradley JS, Byington CL, Shah SS, Alverson B, Carter ER, Harrison C, Kaplan SL, Mace SE, McCracken GH, Jr, Moore MR, et al. The management of community-acquired pneumonia in infants and children older than 3 months of age: clinical practice guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America. Clin Infect Dis. 2011;53(7):e25–76. doi: 10.1093/cid/cir531. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Williams GJ, Macaskill P, Kerr M, Fitzgerald DA, Isaacs D, Codarini M, McCaskill M, Prelog K, Craig JC. Variability and accuracy in interpretation of consolidation on chest radiography for diagnosing pneumonia in children under 5 years of age. Pediatr Pulmonol. 2013;48(12):1195–200. doi: 10.1002/ppul.22806. [DOI] [PubMed] [Google Scholar]
  • 9.Nambu A, Ozawa K, Kobayashi N, Tago M. Imaging of community-acquired pneumonia: roles of imaging examinations, imaging diagnosis of specific pathogens and discrimination from noninfectious diseases. World J Radiol. 2014;6(10):779–93. doi: 10.4329/wjr.v6.i10.779. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.O’Grady KF, Torzillo PJ, Frawley K, Chang AB. The radiological diagnosis of pneumonia in children. Pneumonia (Nathan) 2014;5(Suppl 1):38–51. doi: 10.15172/pneu.2014.5/482. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 11.Gargani L, Volpicelli G. How I do it: lung ultrasound. Cardiovasc Ultrasound. 2014;12:25. doi: 10.1186/1476-7120-12-25. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Soni NJ, Franco R, Velez MI, Schnobrich D, Dancel R, Restrepo MI, Mayo PH. Ultrasound in the diagnosis and management of pleural effusions. J Hosp Med. 2015;10(12):811–6. doi: 10.1002/jhm.2434. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Pereda MA, Chavez MA, Hooper-Miele CC, Gilman RH, Steinhoff MC, Ellington LE, Gross M, Price C, Tielsch JM, Checkley W. Lung ultrasound for the diagnosis of pneumonia in children: a meta-analysis. Pediatrics. 2015;135(4):714–22. doi: 10.1542/peds.2014-2833. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 14.Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009;6(7):e1000097. doi: 10.1371/journal.pmed.1000097. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Whiting PF, Rutjes AW, Westwood ME, Mallett S, Deeks JJ, Reitsma JB, Leeflang MM, Sterne JA, Bossuyt PM. QUADAS-2: a revised tool for the quality assessment of diagnostic accuracy studies. Ann Intern Med. 2011;155(8):529–36. doi: 10.7326/0003-4819-155-8-201110180-00009. [DOI] [PubMed] [Google Scholar]
  • 16.DerSimonian R, Laird N. Meta-analysis in clinical trials. Control Clin Trials. 1986;7(3):177–88. doi: 10.1016/0197-2456(86)90046-2. [DOI] [PubMed] [Google Scholar]
  • 17.Walter SD. Properties of the summary receiver operating characteristic (SROC) curve for diagnostic test data. Stat Med. 2002;21(9):1237–56. doi: 10.1002/sim.1099. [DOI] [PubMed] [Google Scholar]
  • 18.Deeks JJ, Higgins JPT, Altman DG. Analyzing data and undertaking meta-analyses. In: Higgins J, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions 5.0.1.Oxford, UK: The Cochrane Collaboration; 2008. 2008.
  • 19.Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. BMJ. 2003;327(7414):557–60. doi: 10.1136/bmj.327.7414.557. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 20.Huxley RR, Woodward M. Cigarette smoking as a risk factor for coronary heart disease in women compared with men: a systematic review and meta-analysis of prospective cohort studies. Lancet. 2011;378(9799):1297–305. doi: 10.1016/S0140-6736(11)60781-2. [DOI] [PubMed] [Google Scholar]
  • 21.Deeks JJ, Macaskill P, Irwig L. The performance of tests of publication bias and other sample size effects in systematic reviews of diagnostic test accuracy was assessed. J Clin Epidemiol. 2005;58(9):882–93. doi: 10.1016/j.jclinepi.2005.01.016. [DOI] [PubMed] [Google Scholar]
  • 22.Copetti R, Cattarossi L. Ultrasound diagnosis of pneumonia in children. Radiol Med. 2008;113(2):190–8. doi: 10.1007/s11547-008-0247-8. [DOI] [PubMed] [Google Scholar]
  • 23.Iuri D, De Candia A, Bazzocchi M. Evaluation of the lung in children with suspected pneumonia: usefulness of ultrasonography. Radiol Med. 2009;114(2):321–30. doi: 10.1007/s11547-008-0336-8. [DOI] [PubMed] [Google Scholar]
  • 24.Shah VP, Tunik MG, Tsung JW. Prospective evaluation of point-of-care ultrasonography for the diagnosis of pneumonia in children and young adults. JAMA Pediatr. 2013;167(2):119–25. doi: 10.1001/2013.jamapediatrics.107. [DOI] [PubMed] [Google Scholar]
  • 25.Caiulo VA, Gargani L, Caiulo S, Fisicaro A, Moramarco F, Latini G, Picano E, Mele G. Lung ultrasound characteristics of community-acquired pneumonia in hospitalized children. Pediatr Pulmonol. 2013;48(3):280–7. doi: 10.1002/ppul.22585. [DOI] [PubMed] [Google Scholar]
  • 26.Dien SE, Abd ElLatif HM. The value of bedside lung ultrasonography in diagnosis of neonatal pneumonia. Egypt Soc Radiol Nuclear Med. 2013;44:339–47. doi: 10.1016/j.ejrnm.2013.02.005. [DOI] [Google Scholar]
  • 27.Esposito S, Papa SS, Borzani I, Pinzani R, Giannitto C, Consonni D, Principi N. Performance of lung ultrasonography in children with community-acquired pneumonia. Ital J Pediatr. 2014;40:37. doi: 10.1186/1824-7288-40-37. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28.Liu J, Liu F, Liu Y, Wang HW, Feng ZC. Lung ultrasonography for the diagnosis of severe neonatal pneumonia. Chest. 2014;146(2):383–8. doi: 10.1378/chest.13-2852. [DOI] [PubMed] [Google Scholar]
  • 29.Reali F, Sferrazza Papa GF, Carlucci P, Fracasso P, Di Marco F, Mandelli M, Soldi S, Riva E, Centanni S. Can lung ultrasound replace chest radiography for the diagnosis of pneumonia in hospitalized children? Respiration. 2014;88(2):112–5. doi: 10.1159/000362692. [DOI] [PubMed] [Google Scholar]
  • 30.Iorio G, Capasso M, De Luca G, Prisco S, Mancusi C, Laganà B, Comune V. Lung ultrasound in the diagnosis of pneumonia in children: proposal for a new diagnostic algorithm. PeerJ. 2015;3:e1374. doi: 10.7717/peerj.1374. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31.Urbankowska E, Krenke K, Drobczyński Ł, Korczyński P, Urbankowski T, Krawiec M, Kraj G, Brzewski M, Kulus M. Lung ultrasound in the diagnosis and monitoring of community acquired pneumonia in children. Respir Med. 2015;109(9):1207–12. doi: 10.1016/j.rmed.2015.06.011. [DOI] [PubMed] [Google Scholar]
  • 32.Ho MC, Ker CR, Hsu JH, Wu JR, Dai ZK, Chen IC. Usefulness of lung ultrasound in the diagnosis of community-acquired pneumonia in children. Pediatr Neonatol. 2015;56(1):40–5. doi: 10.1016/j.pedneo.2014.03.007. [DOI] [PubMed] [Google Scholar]
  • 33.Ianniello S, Piccolo CL, Buquicchio GL, Trinci M, Miele V. First-line diagnosis of paediatric pneumonia in emergency: lung ultrasound (LUS) in addition to chest-X-ray (CXR) and its role in follow-up. Br J Radiol. 2016;89(1061):20150998. doi: 10.1259/bjr.20150998. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 34.Guerra M, Crichiutti G, Pecile P, Romanello C, Busolini E, Valent F, Rosolen A. Ultrasound detection of pneumonia in febrile children with respiratory distress: a prospective study. Eur J Pediatr. 2016;175(2):163–70. doi: 10.1007/s00431-015-2611-8. [DOI] [PubMed] [Google Scholar]
  • 35.Boursiani C, Tsolia M, Koumanidou C, Malagari A, Vakaki M, Karapostolakis G, Mazioti A, Alexopoulou E. Lung Ultrasound as First-Line examination for the diagnosis of Community-Acquired Pneumonia in Children. Pediatr Emerg Care. 2017;33(1):62–6. doi: 10.1097/PEC.0000000000000969. [DOI] [PubMed] [Google Scholar]
  • 36.Man SC, Fufezan O, Sas V, Schnell C. Performance of lung ultrasonography for the diagnosis of communityacquired pneumonia in hospitalized children. Med Ultrason. 2017;19(3):276–81. doi: 10.11152/mu-1027. [DOI] [PubMed] [Google Scholar]
  • 37.Yadav KK, Awasthi S, Parihar A. Lung Ultrasound is comparable with chest Roentgenogram for diagnosis of community-acquired P``neumonia in Hospitalised Children. Indian J Pediatr. 2017;84(7):499–504. doi: 10.1007/s12098-017-2333-1. [DOI] [PubMed] [Google Scholar]
  • 38.Yilmaz HL, Özkaya AK, Sarı Gökay S, Tolu Kendir Ö, Şenol H. Point-of-care lung ultrasound in children with community acquired pneumonia. Am J Emerg Med. 2017;35(7):964–9. doi: 10.1016/j.ajem.2017.01.065. [DOI] [PubMed] [Google Scholar]
  • 39.Claes AS, Clapuyt P, Menten R, Michoux N, Dumitriu D. Performance of chest ultrasound in pediatric pneumonia. Eur J Radiol. 2017;88:82–7. doi: 10.1016/j.ejrad.2016.12.032. [DOI] [PubMed] [Google Scholar]
  • 40.Samson F, Gorostiza I, González A, Landa M, Ruiz L, Grau M. Prospective evaluation of clinical lung ultrasonography in the diagnosis of community-acquired pneumonia in a pediatric emergency department. Eur J Emerg Med. 2018;25(1):65–70. doi: 10.1097/MEJ.0000000000000418. [DOI] [PubMed] [Google Scholar]
  • 41.Zhan C, Grundtvig N, Klug BH. Performance of Bedside Lung Ultrasound by a Pediatric Resident: a useful Diagnostic Tool in Children with suspected pneumonia. Pediatr Emerg Care. 2018;34(9):618–22. doi: 10.1097/PEC.0000000000000888. [DOI] [PubMed] [Google Scholar]
  • 42.Biagi C, Pierantoni L, Baldazzi M, Greco L, Dormi A, Dondi A, Faldella G, Lanari M. Lung ultrasound for the diagnosis of pneumonia in children with acute bronchiolitis. BMC Pulm Med. 2018;18(1):191. doi: 10.1186/s12890-018-0750-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 43.Lissaman C, Kanjanauptom P, Ong C, Tessaro M, Long E, O’Brien A. Prospective observational study of point-of-care ultrasound for diagnosing pneumonia. Arch Dis Child. 2019;104(1):12–8. doi: 10.1136/archdischild-2017-314496. [DOI] [PubMed] [Google Scholar]
  • 44.Bloise S, La Regina DP, Pepino D, Iovine E, Laudisa M, Di Mattia G, Nicolai A, Nenna R, Petrarca L, Mancino E, et al. Lung ultrasound compared to chest X-ray for the diagnosis of CAP in children. Pediatr Int. 2021;63(4):448–53. doi: 10.1111/ped.14469. [DOI] [PubMed] [Google Scholar]
  • 45.Zhu J, Chen P, Jiang D. Clinical Value and Imaging Features of Bedside High-Frequency Ultrasound Imaging in the Diagnosis of Neonatal Pneumonia. Contrast Media Mol Imaging. 2022;2022:4805300. doi: 10.1155/2022/4805300. [DOI] [PMC free article] [PubMed] [Google Scholar] [Retracted]
  • 46.Don M, Fiotti N, Bizjak R, Guerra M, Nicolini G, Barbi E, Toller I, Narducci F, Tortorella ML, Dragovic D, et al. Multicentre study supports the use of lung ultrasound in diagnosing paediatric community-acquired pneumonia. Acta Paediatr. 2022;111(2):401–2. doi: 10.1111/apa.16131. [DOI] [PubMed] [Google Scholar]
  • 47.Guitart C, Rodríguez-Fanjul J, Bobillo-Perez S, Carrasco JL, Inarejos Clemente EJ, Cambra FJ, Balaguer M, Jordan I. An algorithm combining procalcitonin and lung ultrasound improves the diagnosis of bacterial pneumonia in critically ill children: the PROLUSP study, a randomized clinical trial. Pediatr Pulmonol. 2022;57(3):711–23. doi: 10.1002/ppul.25790. [DOI] [PubMed] [Google Scholar]
  • 48.Orso D, Ban A, Guglielmo N. Lung ultrasound in diagnosing pneumonia in childhood: a systematic review and meta-analysis. J Ultrasound. 2018;21(3):183–95. doi: 10.1007/s40477-018-0306-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 49.Tsou PY, Chen KP, Wang YH, Fishe J, Gillon J, Lee CC, Deanehan JK, Kuo PL, Yu DTY. Diagnostic accuracy of Lung Ultrasound performed by novice Versus Advanced sonographers for Pneumonia in children: a systematic review and Meta-analysis. Acad Emerg Med. 2019;26(9):1074–88. doi: 10.1111/acem.13818. [DOI] [PubMed] [Google Scholar]
  • 50.Xin H, Li J, Hu HY. Is lung ultrasound useful for diagnosing pneumonia in children? A Meta-analysis and systematic review. Ultrasound Q. 2018;34(1):3–10. doi: 10.1097/RUQ.0000000000000330. [DOI] [PubMed] [Google Scholar]
  • 51.Yan JH, Yu N, Wang YH, Gao YB, Pan L. Lung ultrasound vs chest radiography in the diagnosis of children pneumonia: systematic evidence. Med (Baltim) 2020;99(50):e23671. doi: 10.1097/MD.0000000000023671. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 52.Levinsky Y, Mimouni FB, Fisher D, Ehrlichman M. Chest radiography of acute paediatric lower respiratory infections: experience versus interobserver variation. Acta Paediatr. 2013;102(7):e310–314. doi: 10.1111/apa.12249. [DOI] [PubMed] [Google Scholar]
  • 53.Nascimento-Carvalho CM, Araújo-Neto CA, Ruuskanen O. Association between bacterial infection and radiologically confirmed pneumonia among children. Pediatr Infect Dis J. 2015;34(5):490–3. doi: 10.1097/INF.0000000000000622. [DOI] [PubMed] [Google Scholar]
  • 54.Self WH, Courtney DM, McNaughton CD, Wunderink RG, Kline JA. High discordance of chest x-ray and computed tomography for detection of pulmonary opacities in ED patients: implications for diagnosing pneumonia. Am J Emerg Med. 2013;31(2):401–5. doi: 10.1016/j.ajem.2012.08.041. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 55.Jones BP, Tay ET, Elikashvili I, Sanders JE, Paul AZ, Nelson BP, Spina LA, Tsung JW. Feasibility and safety of substituting lung ultrasonography for chest radiography when diagnosing pneumonia in children: a Randomized Controlled Trial. Chest. 2016;150(1):131–8. doi: 10.1016/j.chest.2016.02.643. [DOI] [PubMed] [Google Scholar]
  • 56.Ferrada P, Wolfe L, Anand RJ, Whelan J, Vanguri P, Malhotra A, Goldberg S, Duane T, Aboutanos M. Use of limited transthoracic echocardiography in patients with traumatic cardiac arrest decreases the rate of nontherapeutic thoracotomy and hospital costs. J Ultrasound Med. 2014;33(10):1829–32. doi: 10.7863/ultra.33.10.1829. [DOI] [PubMed] [Google Scholar]
  • 57.Mercaldi CJ, Lanes SF. Ultrasound guidance decreases complications and improves the cost of care among patients undergoing thoracentesis and paracentesis. Chest. 2013;143(2):532–8. doi: 10.1378/chest.12-0447. [DOI] [PubMed] [Google Scholar]
  • 58.Long L, Zhao HT, Zhang ZY, Wang GY, Zhao HL. Lung ultrasound for the diagnosis of pneumonia in adults: a meta-analysis. Med (Baltim) 2017;96(3):e5713. doi: 10.1097/MD.0000000000005713. [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

13052_2024_1583_MOESM1_ESM.docx (15KB, docx)

Additional file 1: Table S1. The methodological quality of included studies.

13052_2024_1583_MOESM2_ESM.eps (996.3KB, eps)

Additional file 2: Figure S1. The summary PLR and NLR of LUS for detecting pneumonia.

13052_2024_1583_MOESM3_ESM.eps (1.1MB, eps)

Additional file 3: Figure S2. The summary DOR of LUS for detecting pneumonia.

13052_2024_1583_MOESM4_ESM.eps (490.4KB, eps)

Additional file 4: Figure S3. The publication bias of LUS for detecting pneumonia.

Data Availability Statement

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Articles from Italian Journal of Pediatrics are provided here courtesy of BMC

RESOURCES