146 AJTCCM VOL. 28 NO. 4 2022
EDITORIAL
During the early 19th century, fascination with measuring the speed
of sound underwater ultimately led to the development of SONAR
(sound navigation and ranging).[1] These early developments of
SONAR underwent major advances in the battle for naval supremacy
during the rst and second world wars.[1] It was, however, only within
the past 60 years that ultrasound for applications in the medical eld
gained momentum, starting with initial attempts to diagnose brain
tumours and abdominal and pelvic masses using large and unpractical
ultrasound machines, and leading to the current routine application
of ultrasound in disciplines such as obstetrics and gynaecology,
cardiology and others with portable hand-held devices.[1] Although
ultrasound is a routine part of the diagnostic and therapeutic services
provided by radiologists and diagnostic sonographers, the past two
decades really saw ultrasound coming full circle back into the hands
of treating clinicians at the point of care. Emergency and critical
care physicians were early adopters of point-of-care ultrasonography
to assist in the rapid diagnosis and treatment of patients with
time-sensitive life-threatening illnesses.[2] Currently, point-of-care
ultrasonography is embraced as an essential cost-eective bedside
tool to improve on the sensitivity of the clinical examination and
to perform interventions, such as central line placement or pleural
eusion sampling, under direct vision and therefore limiting the risk
of iatrogenic complications.[3]
Since air is the ‘enemy’ of ultrasound, it was initially thought that
ultrasound could not be applied for lung imaging. Unlike conventional
ultrasound imaging, where the acoustic properties of so tissue enable
the shape of dierent organs to be visualised fairly accurately, air in
normal lungs impedes ultrasound waves.[4] Despite this hindrance,
early pioneers of lung ultrasonography noted that normal and
diseased lung tissue is associated with certain image artefacts.
The ability of clinicians to differentiate normal from diseased
lung by interpreting the artefactual pattern made lung ultrasound
an attractive tool to respiratory physicians in the management of
patients with pulmonary disorders.[4] One of the most prominent
artefacts is the hyperechoic pleural line, resulting from ultrasound
waves reected from the pleura.[5] Movement of normal visceral
pleura relative to parietal pleura creates ‘lung sliding’.[5] Loss of
normal lung sliding may therefore indicate air between the visceral
and parietal pleura, or lung disease abutting the visceral pleura and
impeding pleural movement. Reverberation artefacts of the pleura
result in equidistant horizontal lines on the ultrasound image,
called A-lines.[6] An increase in lung density, such as with interstitial
inammation or pulmonary oedema, results in loss of A-lines. With
interstitial oedema or inammation, ultrasound waves deect from
denser lung interstitium, creating vertical lines coming from the
pleura on ultrasound imaging, called B-lines.[6] B-lines can also be
used to qualitatively judge the intrapulmonary water content of the
lungs, since the more numerous the B-lines are, the more water the
lungs contain.[7]
As respiratory physicians became more adept at lung
ultrasonography, it naturally followed for ultrasound to be used in
clinical practice when performing diagnostic interventions involving
the chest wall, pleural space and lungs.[8] Sub-pleural pneumonia
or lung masses are recognised on lung ultrasound as hypoechoic
lesions, associated with irregular borders where the mass borders
normal lung tissue.[9] It is this ability to identify lung masses abutting
the pleura that allows diagnostic samples to be taken by means of
ne-needle aspiration or biopsy under ultrasound guidance.[10] e
advantages of clinicians performing ultrasound-guided procedures
are numerous. It saves time, because diagnostic procedures can be
performed at the time of consultation. It is also a cost-eective option
that circumvents the need for expensive computed tomography
(CT)-guided procedures.[11] e portability of ultrasound machines
makes it possible for procedures to be performed wherever patients
are located, unlike CT machines, which are not portable and are
oen unavailable in limited-resource or rural settings. CT machines
also expose patients to unnecessary radiation. Ultrasound-guided
interventions reduce the risk of complications,[6,12] thereby potentially
limiting the risk of litigation. It is easy to learn lung ultrasonography.
House et al.[13] found that the majority of physicians in a low-resource
setting were able to interpret lung ultrasound prociently aer only
1 day of training.
The study by Benbarka et al.[14] in this issue of AJTCCM
further adds to the body of knowledge on the use of ultrasound
in performing diagnostic interventions for thoracic masses.
The investigators evaluated all cases of thoracic plasmacytoma
diagnosed by respiratory physicians at their hospital’s pulmonology
division over a 12-year period. Plasmacytoma is a rare, frequently
unsuspected haematological malignancy that can present with
solitary masses in any organ.[15,16] e study demonstrates the utility
and feasibility of using chest ultrasound to assist in the diagnosis of
plasmacytoma. e availability of cytopathologists on site to rapidly
analyse cytology samples increases diagnostic certainty. e ability
of respiratory physicians to perform ultrasound of the chest and use
this modality to guide diagnostic procedures ultimately provides a
one-stop service for patients with accessible lung, pleural or chest wall
masses. As part of a patient-centred service, rapid on-site evaluation
(ROSE) has the potential to provide the patient with a diagnosis
and management plan immediately aer the procedure. is is an
important consideration in low socioeconomic settings where the
cost incurred by patients to attend healthcare establishments can
be a considerable obstacle. Reducing the turnaround time between
sampling and reporting of results is an important consideration in
settings where loss to follow-up may be a concern. e growing
recognition that lung ultrasound can assist in the rapid diagnosis
of specic respiratory diseases makes it an important modality that
should be normalised in the clinical setting.[17]
S D Maasdorp, MB ChB, MMed (Int), FCP (SA), Cert Pulmonology
(SA) Phys
Department of Internal Medicine, Faculty of Health Sciences,
University of the Free State, South Africa
maasdorpSD1@ufs.ac.za
Normalising lung ultrasound
AJTCCM VOL. 28 NO. 4 2022 147
EDITORIAL
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3. Lee L, Decara JM. Point-of-care ultrasound. Curr Cardiol Rep 2020;22(11):149.
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10. Christiansen IS, Clementsen PF, Bodtger U, Naur TMH, Pietersen PI, Laursen CB.
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019.1579632
11. Moreira BL, Guimaraes MD, de Oliveira AD, et al. Value of ultrasound in the imaging-
guided transthoracic biopsy of lung lesions. Ann orac Surg 2014;97(5):1795-1797.
https://doi.org/10.1016/j.athoracsur.2013.07.105
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biopsy of the lung: Sensitivity and safety variables. Eur Radiol 2021;31(11):8272-8281.
https://doi.org/10.1007/s00330-021-07888-9
13. House DR, Amatya Y, Nti B, Russell FM. Lung ultrasound training and evaluation for
prociency among physicians in a low-resource setting. Ultrasound J 2021;13(1):34.
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14. Benbarka SS, Shubert PT, Irusen EM, Allwood BW, Koegelenberg CFN. e utility of
chest ultrasound-guided ne-needle biopsy in the diagnosis of plasmacytoma. Afr J
oracic Crit Care Med 2022;28(4):167-171. https://doi.org/10.7196/AJTCCM.2022.
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15. Lenka J, Sharma N. Extramedullary pulmonary plasmacytoma as a complication of
relapsed multiple myeloma. Chest 2021;160(4 Suppl):A2073. https://doi.org/10.1016/j.
chest.2021.07.1830
16. Wise JN, Schaefer RF, Read RC. Primary pulmonary plasmacytoma: A case report.
Chest 2001;120(4):1405-1407. https://doi.org/10.1378/chest.120.4.1405
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medicine: Training and clinical practice. Crit Ultrasound J 2016;8(1):10. https://doi.
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