Lung ultrasound for the diagnosis of community-acquired pneumonia in children
Pediatr Radiol
Lung ultrasound for the diagnosis of community-acquired pneumonia in children
Jacob A. M. Stadler 0 1 2 4 5
Savvas Andronikou 0 1 2 4 5
Heather J. Zar 0 1 2 4 5
0 Department of Radiology, University of Cape Town , Cape Town , South Africa
1 University of Bristol , Bristol , UK
2 Department of Paediatric Radiology, Bristol Royal Hospital for Children , Upper Maudlin Street, Bristol BS2 8BJ , UK
3 Savvas Andronikou
4 MRC Unit on Child and Adolescent Health, University of Cape Town , Cape Town , South Africa
5 Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital , Cape Town , South Africa
Ultrasound (US) has been proposed as an alternative first-line imaging modality to diagnose communityacquired pneumonia in children. Lung US has the potential benefits over chest radiography of being radiation free, subject to fewer regulatory requirements, relatively lower cost and with immediate bedside availability of results. However, the uptake of lung US into clinical practice has been slow and it is not yet included in clinical guidelines for community-acquired pneumonia in children. The aim of this review is to give an overview of the equipment and techniques used to perform lung US in children with suspected pneumonia and the interpretation of relevant sonographic findings. We also summarise the current evidence of diagnostic accuracy and reliability of lung US compared to alternative imaging modalities in children and critically consider the strengths and limitations of lung US for use in children presenting with suspected community-acquired pneumonia.
Children; Community-acquired pneumonia; Lung; Pneumonia; Ultrasound
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Department of Paediatrics and Child Health,
University of Cape Town,
Cape Town, South Africa
Introduction
Pneumonia remains the leading cause of death in children
outside the neonatal period, but confirmation of a clinically
suspected diagnosis, either to guide management or for
consistent case definition in epidemiological and vaccine studies,
remains problematic. Chest radiography is generally
considered the first-line standard-of-care imaging modality to
investigate suspected pneumonia, with alveolar consolidation or
interstitial infiltrates combined with high serum C-reactive
protein considered diagnostic for bacterial pneumonia. However,
chest radiography cannot be considered a diagnostic gold
standard due to wide inter- and intraobserver variability when
interpreting results, differing radiologic manifestations of
pneumonia and possible lack of sensitivity and specificity
[
1–7
]. Due to the potentially harmful effects of radiation
exposure, some clinical guidelines advise against the routine use of
chest radiography in uncomplicated acute lower respiratory
infections in childhood populations with high vaccination
cover for Haemophilus influenzae type B and Pneumococcus [
8,
9
]. The use of chest radiography is further limited by the cost
and expertise required for operating a radiology service.
Historically, ultrasound (US) has played a relatively minor
role in pneumonia diagnosis, being viewed mostly as a
complementary tool to standard radiography in complicated
disease. More recently, decreased cost and increased availability
of portable US technology as well as its potential to decrease
radiation exposure has renewed interest in the use of lung US
as a first-line imaging modality for the diagnosis of
pneumonia, especially in children. Methods initially used in adult
studies were adapted for use in children and feasibility,
diagnostic accuracy and reliability have now been assessed in
children in multiple settings. As the use of US is not subject
to the same regulatory requirements as radiography and the
cost of basic US technology is considerably lower than
operating a basic radiology service, it has the potential to expand
access to diagnostic imaging in low resource settings and
could lead to overall cost savings. Clinician-driven use with
immediate availability of results is another reason US may be
favoured in certain settings. This article aims to describe the
technique and sonographic findings used for US diagnosis of
community-acquired pneumonia in children and summarise
current evidence of its diagnostic accuracy and reliability.
Technique and equipment
The type and size of the transducer depends on the age and
size of the child. For an intercostal approach, small linear or
micro-convex probes are preferred. In lung US, where the
pleura and subpleural space are being assessed, a
highfrequency transducer (5-15 MHz) is appropriate. Children
can be scanned in the upright, supine or decubitus position.
Scanning an uncooperative child can be challenging but is
usually feasible. One approach is to scan the child while he
is seated on a caregiver’s lap (even while breastfeeding) to
minimise anxiety. To improve control of the probe, the base
of the operator’s hand can be stabilized against the chest wall.
This minimises movemen (...truncated)