Figures
- FIGURE 1
Levels of diagnostic test efficacy [8] depicting the available evidence for bedside chest ultrasound at each level and the relative clinical impact.
- FIGURE 2
Selected chest ultrasound images. a) Sea-shore sign. Granular “sea-shore” appearance of normal lung sliding on M mode. b) Barcode sign. Horizontal “bar-code” appearance with loss of lung sliding on M mode. c) B-lines. Asterisks indicate comet tail artefacts arising from the pleural line (B-lines). d) Simple pleural effusion. “E” indicates anechoic free-flowing effusion. “L” indicates compressed atelectatic lung. “D” indicates diaphragm. e) Consolidation. “C” indicates consolidation. “D” indicates diaphragm. “L” indicates liver. “S” indicates serrated distal margins of the consolidation. Arrows indicate air bronchograms. f) Lung tumour. The arrow indicates the smooth distal margin of the mass.
- FIGURE 3
Chest ultrasound syndromes: available evidence at each level of efficacy. Grey shading indicates a substantial body of evidence for that level of efficacy.
Tables
- TABLE 1
Chest ultrasound syndromes: typical sonographic findings and relevant differential diagnoses
Chest ultrasound syndrome Sonographic features Differential diagnosis Pleural Pneumothorax Absent lung sliding
Absent B-lines
Lung point (specific for pneumothorax)Pneumothorax, emphysema, pleural adhesions Pleural effusion Echo-free space
Quad sign (fluid-colour and sinusoid signs more specific for effusion)Pleural effusion, pleural thickening, parenchymal fluid collection Parenchymal Consolidation Tissue-like pattern (iso- or hypo-echoic)
Echogenic air-bronchogramsPneumonia, atelectasis, neoplasm, pulmonary infarct Interstitial syndrome B-lines Diffuse: cardiogenic pulmonary oedema, non-cardiogenic pulmonary oedema, interstitial lung disease
Focal: pneumonia, focal fibrosis, pulmonary contusion, pulmonary infarction, lymphangitisMusculoskeletal Chest wall applications Interrupted parietal pleura and restricted pleural movement in the context of subpleural mass Malignant chest wall invasion Diaphragm applications Impaired thickening
Reduced excursionDiaphragmatic paresis, extrinsic limitation of diaphragm - TABLE 2
Diagnostic accuracy of ultrasound (US) in pleural chest syndromes: evidence from systematic reviews
Number of studies Population, unit of analysis US features, comparator Reference standard Prevalence and number Sensitivity Specificity Pneumothorax Wilkerson 2010 [25] 4 studies
No meta-analysisBlunt trauma,
By patient (3 studies)
By hemithorax (1 study)Not stated
CXRChest CT or release of air 21.5–30.1% of 497 patients
11.5% of 218 hemithoracesUS: 86–98%
CXR: 28–75%US: 97–100%
CXR: 100%Ding 2011 [24] 20 studies Trauma, post-lung biopsy, critically ill
By hemithorax#Absent lung sliding, absent comets, lung point
CXRChest CT or clinical findings and release of air 13.2% of 7569 hemithoraces US: 88%
CXR: 52%US: 99%
CXR: 100%Alrajhi 2012 [27] 8 studies Trauma, iatrogenic
By patient#Absent lung sliding, absent comets
CXRChest CT or release of air Not stated (unable to calculate)
1048 patientsUS: 90.9%
CXR: 50.2%US: 98.2%
CXR: 99.4%Alrajab 2013 [28] 13 studies Trauma, post-lung biopsy, critically ill
By hemithoraxNot defined
CXRChest CT 22.5% of 3028 hemithoraces US: 78.6%
CXR: 39.8%US: 98.4%
CXR: 99.3%Ebrahimi 2014 [29] 28 studies Trauma, iatrogenic, critically ill
By patient#Not stated
CXRChest CT 20% of 5314 patients US: 87%
CXR: 46%US: 99%
CXR: 100%Pleural effusion Grimberg 2010 [30] 4 studies Trauma, heart failure, ICU patients with ARDS
By patientNot stated
CXRCT or drainage 27.6% of 924 patients US: 92–96%
CXR: 24–100%US: 88–100%
CXR: 85–100%Yousefifard 2016 [31] 12 studies Trauma, heart failure, critically ill, surgical patients
By patientNot stated
CXRCT, US, CXR 41.5% of 1554 patients US: 94%
CXR: 51%US: 98%
CXR: 91%CXR: chest radiography; CT: computed tomography; ICU: intensive care unit; ARDS: acute respiratory distress syndrome. #: Included and pooled studies reporting the alternative unit of analysis, by either doubling the number of patients or halving the number of hemithoraces in those studies.
- TABLE 3
Diagnostic accuracy of ultrasound (US) for consolidation: evidence from systematic reviews
Number of studies Population, unit of analysis US features, comparator Reference standard Prevalence and number Sensitivity Specificity Consolidation Hew 2015 [32] 4 studies
No meta-analysisHospitalised adults with acute respiratory failure,
By patient, lung or lung regionConsolidation
CXRCT only Unable to summarise prevalence from heterogeneous units of analysis
224 patientsUS: 98–100%
CXR: 38–68%US: 78–100%
CXR: 89–95%Pneumonia Hu 2014 [65] 9 studies Included adults, children, neonates
By patientUnstated CXR/CT, or CXR only, or clinical diagnoses 62.5% of 1080 patients US: 97% US: 94% Chavez 2014 [66] 10 studies Adults with clinical suspicion of pneumonia, or acute respiratory failure
By patient, lung, or lung region#Consolidation or “alveolar and interstitial” CT only, or CXR or CT, or clinical diagnosis/CT/CXR Calculated at 50% of 1098 patients in studies analysed by patient US: 94% US: 96% Ye 2015 [67] 5 studies Clinically suspected pneumonia in adults
By patientUni/bilateral or focal alveolar–interstitial syndrome, or consolidation with air bronchograms Hospital discharge diagnosis 67.3% of 742 patients US: 95%
CXR: 77%US: 90%
CXR: 91%Pulmonary embolism Squizzato 2013 [68] 10 studies Clinical suspicion of PE
By patient5 studies: round or wedge-shaped lesions
5 studies: not reported6 studies: composite
4 studies: CTPA or V′/Q′ or MRA61% of 887 patients 87% 81.8% Jiang 2015 [69] 13 studies Adults with suspected PE
By patient7 studies: round or wedge-shaped lesions
6 studies: not reported8 studies: composite
5 studies: CTPA or V′/Q′ or MRA50.6% 85% 83% CXR: chest radiography; CT: computed tomography; PE: pulmonary embolus; CTPA: computed tomography pulmonary angiogram; V′/Q′: ventilation–perfusion scan; MRA: magnetic resonance angiogram;. #: Included and pooled studies reporting all three units of analysis.
- TABLE 4
Diagnostic accuracy of ultrasound (US) in the interstitial syndrome: evidence from systematic reviews
Number of studies Population, unit of analysis US features Reference standard Prevalence and number Sensitivity Specificity Acute cardiogenic pulmonary oedema Al Deeb 2014 [94] 7 studies Patients presenting with undifferentiated dyspnoea
By patientUS criteria not restricted as long as B-lines were used 5 studies: blinded chart review
2 studies:
final diagnosis45% of 1075 patients 94.1% 92.4% Martindale 2016 [95] 8 studies Adults presenting to ED with dyspnoea
By patientAt least 3 B-lines in each lung
Performed by emergency specialistsClinical diagnosis by independent reviewers blinded to index test result 45.6% of 1914 patients 85.3% 92.7% ED: emergency department.
