Many care providers are not pediatric specialists by practice, and evaluation and treatment of children is less familiar than with adults.. This is especially relevant to chest disorders
Trang 2Preface Pediatric Chest Imaging
Donald P Frush, MD Guest Editor
Children are frightening Frightening? In nearly
all contexts this statement would be indefensible
In medicine, however, children are often frightening
For one thing, clinical evaluation in young children
can be more difficult than with adults In addition, in
the acutely ill or injured child, reserve can be limited
and appropriate assessment, including imaging
evalu-ation, and subsequent care are critically important
in improving outcome Many care providers are not
pediatric specialists by practice, and evaluation and
treatment of children is less familiar than with adults
Moreover, the spectrum of disorders that affects the
pediatric population can be quite different from
dis-orders more easily recognized in adults Often there
is an extra layer of emotional concern, or anxiety,
because a child is involved Together, these issues
re-inforce the importance of resources which facilitate
the diagnosis and care of the sick or injured child
This is especially relevant to chest disorders, because
thoracic abnormalities are common in children, and
is also relevant to radiologists, because imaging
evaluation of the chest is frequently one of the first
(or only) tools used after the clinical assessment
Presumably, you are reading this because you
are an imager, or interested in imaging evaluation,
and because you are caring for children in some capacity Perhaps you are reading this because, like many of us who have contributed to this work, you understand the importance of being familiar with the imaging evaluation of chest disorders in infants and children Like many of us, you also understand that current information on many topics is difficult
to find, and when available, not a comprehensive resource This issue of Radiologic Clinics of North America, then, is compiled to provide a contempo-rary resource for those interested in imaging evalua-tion of the pediatric chest
I am fortunate and thankful to have enlisted an internationally recognized panel of pediatric radiolo-gists who bring an additional expertise in thoracic imaging Because of the many years of expertise, the work reflects not only knowledge, but wisdom regarding the approach and interpretation of chest imaging that only experience brings Topics covered include focused evaluation of common clinical sce-narios such as pulmonary infection, airway and esophageal disorders, trauma, and chest wall dis-orders; patterns of presentation, such as interstitial lung disease, and lung and mediastinal masses; imaging techniques including ultrasonography and
D 2005 Elsevier Inc All rights reserved.
Trang 3Imaging Evaluation of Congenital Lung Abnormalities in
Infants and Children Anne Paterson, MB BS, MRCP, FRCR, FFR RCSI
Radiology Department, Royal Belfast Hospital for Sick Children, 180 Falls Road, Belfast BT12 6BE, UK
Congenital lung abnormalities include a wide
spectrum of conditions and are an important cause
of morbidity and mortality in infants and children
This article discusses focal lung abnormalities (eg,
congenital lobar emphysema [CLE], congenital cystic
adenomatoid malformation [CCAM],
bronchopulmo-nary foregut malformations [BPFM], pulmobronchopulmo-nary
sequestrations) and the dysmorphic lung (lung-lobar
agenesis – hypoplasia complex) Pulmonary
arterio-venous malformations (AVMs) are also included
Thus, anomalies affecting the pulmonary
paren-chyma, its arterial supply, and venous drainage are
discussed Disorders of the airways are described
elsewhere in this issue
Congenital lobar emphysema
Lobar emphysema can either be acquired, or
secondary or congenital CLE refers to progressive
overinflation of a pulmonary lobe secondary to air
trapping; a ball-valve mechanism allows air into the
lobe when there is negative intrathoracic pressure
during inspiration, but fails to allow the air out during
expiration Bronchomalacia caused by a deficiency
of bronchial cartilage, bronchostenosis,
broncho-torsion, obstructive mucosal flaps or mucosal
thick-ening, cartilaginous septa, and bronchial atresia have
all been described pathologically in CLE lobectomy
specimens [1 – 5] In others, no cause is found
Secondary lobar emphysema may result if the
bron-chus is extrinsically compressed, for example by an enlarged right ventricular outflow tract in patients with congenital heart disease[1,2] Indeed, there is a reported increase in the incidence of congenital heart disease in association with CLE [2,4] Lobar over-inflation may also occur with an intraluminal ob-struction, such as an aspirated foreign body Some authors prefer the expression congenital lobar overinflation to CLE This is because micro-scopically, CLE specimens do not always demon-strate alveolar destruction Rather, the alveoli are overdistended but intact [4,6,7] In a pathologic variant of CLE known as the polyalveolar lobe, the alveoli are normal in size or small, but are increased
in number threefold to fivefold [8] The airways are normal When the alveoli distend with air, the lobe overinflates because of the sheer number of air spaces
Clinically, most infants with CLE present within the first 6 months of life, with symptoms and signs
of respiratory distress The earlier the child presents, the more severe is the involvement There is a pre-ponderance of male patients The chest radiograph remains the primary imaging tool CLE has a pre-dilection for the upper lobes and right middle lobe The lower lobes are involved in less than 1% of cases Bilateral or multifocal involvement is rare[3] The appearance on the chest radiograph depends on timing: if the radiograph is taken in the first 24 hours
of life, the involved lobe is seen to be distended and opaque, because of retained fetal lung fluid This fluid progressively clears by the tracheobronchial system, lymphatic vessels, and capillary network The lobe increases in size as it distends with air and demonstrates acinar shadowing, a reticular interstitial
D 2005 Elsevier Inc All rights reserved.
E-mail address: annie.paterson@royalhospitals.n-i.
nhs.uk