pulmonary hypoplasia

Absent left
main pulmonary artery with patent ductus arteriosus. a) Coronal, b) Sagittal MIP and c) rotated 3D VRT images. The white arrow refers to a dilated patent ductus aretriosus. Note the absence of the left main pulmonary artery and right sided aortic arch.
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Absent left
main pulmonary artery with patent ductus arteriosus. CT pulmonary angiography coronal reformatted image showing hypoplastic left lung with abnormally elevated left diaphragmatic copula. Dorsal scoliotic deformity with convexity to the left side noted.
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Right
Pulmonary Artery Atresia with Right Lung Hypoplasia. Volume rendering reconstruction of the thoracic vessels, no right pulmonary artery or segmentar and subsegmentary vessels are seen on the right hemithorax
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Infant with
respiratory distress. CXR AP shows multiple left-sided anterior and multiple right-sided posterior rib fusions and a mild curvature of the spine convex left resulting in a small thorax.The diagnosis was congenital scoliosis secondary to rib fusion causing pulmonary hypoplasia.
pediatricimaging.org • CC-by-nc-sa 4.0
Absent left
main pulmonary artery with patent ductus arteriosus. CT pulmonary angiography, axial MIP image revealed dilatation of the pulmonary trunk and right main pulmonary artery. Note absence of arterial flow to the left lung
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Absent left
main pulmonary artery with patent ductus arteriosus. CT pulmonary angiography, axial MIP image revealed oligemic left lung which is supplied with dilated intercostal arteries (yellow arrow).
www.eurorad.org • CC by-nc-sa-4.0
Absent left
main pulmonary artery with patent ductus arteriosus. a) Coronal, b) Sagittal MIP and c) rotated 3D VRT images. The white arrow refers to a dilated patent ductus aretriosus. Note the absence of the left main pulmonary artery and right sided aortic arch.
www.eurorad.org • CC by-nc-sa-4.0
Absent left
main pulmonary artery with patent ductus arteriosus. a) Coronal, b) Sagittal MIP and c) rotated 3D VRT images. The white arrow refers to a dilated patent ductus aretriosus. Note the absence of the left main pulmonary artery and right sided aortic arch.
www.eurorad.org • CC by-nc-sa-4.0
Absent left
main pulmonary artery with patent ductus arteriosus. CT pulmonary angiography, axial MIP image revealed oligemic left lung with absent left pulmonary arterial supply. This is associated with increased right pulmonary vasculature.
www.eurorad.org • CC by-nc-sa-4.0
Newborn with
an amniotic fluid leak in-utero. CXR AP shows bilateral poorly developed and poorly expanded lungs.The diagnosis was oligohydramnios causing pulmonary hypoplasia.
pediatricimaging.org • CC-by-nc-sa 4.0
Imaging of
congenital lung diseases presenting in the adulthood: a pictorial review. Imaging findings of pulmonary hypoplasia. Chest X-ray (a) and axial CT image (b) of a 26-year-old male presenting with recurrent infection demonstrate pulmonary hypoplasia of the right lung. Although bronchi and alveoli are present in underdeveloped lungs, the size of the right lung is decreased. Consolidations due to infection can also be seen on axial CT (b)
insightsimaging.springeropen.com • CC-by-4.0
Beyond
bronchitis: a review of the congenital and acquired abnormalities of the bronchus. Congenital pulmonary and bronchial malformation. a Illustrations demonstrating lobar bronchial malformations resulting in agenesis, aplasia, or hypoplasia as compared to normal. b Frontal chest x-ray demonstrating agenesis of the right mainstem bronchus and right lung (*); note the hyperexpanded left lung crossing the midline (triangle)
insightsimaging.springeropen.com • Open Access
Right
Pulmonary Artery Atresia with Right Lung Hypoplasia. Postero anterior view of chest radiograph shows loss of right lung volume and mediastinal shift towards the right, with hyperinflation of the left lung
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Right
Pulmonary Artery Atresia with Right Lung Hypoplasia. At the level of the carina, the difference in lung volume and deviation of the mediastinum to the right areclear as well as is the hyperinflation of the left lung
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Right
Pulmonary Artery Atresia with Right Lung Hypoplasia. At the level of the main pulmonary artery and left pulmonary artery, no right pulmonary artery is identifiable
www.eurorad.org • CC by-nc-sa-4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Pulmonary hypoplasia (PH) refers to deficient or incomplete development of parts of the lung. It can develop as a result of a number of other in utero anomalies.

Epidemiology

The true prevalence is not well known (1.4% of all births according to Knox et al. ), but in cases of premature rupture of membranes at 15-28 weeks gestation, the reported prevalence of pulmonary hypoplasia ranges from 9 to 28% .

Pathology

It is characterized by the presence of both bronchi (albeit rudimentary) and alveoli in an under-developed lobe. Both the size and the weight of the lung is reduced.

There are normally four stages of fetal lung development where the pathological process can occur at any level

  • embryonic: from conception ~5 week
  • pseudoglandular: from ~5-17 week
  • canalicular: from ~16- 24 week: this stage may be more affected by oligohydramnios
  • terminal sac or alveolar period: from 24 week to term and beyond
Etiology

There are several key factors required for the adequate development of the lung. These are:

  • sufficient amniotic fluid volumes
  • adequate volume of the thoracic cavity
  • normal breathing movement
  • normal fluid within the lung

A deficiency in any of these could lead to pulmonary hypoplasia.

Most cases of pulmonary hypoplasia are secondary to other congenital anomalies or pregnancy complications. Some cases however can occur as a primary event .

With secondary causes, it can result from factors directly or indirectly compromising the thoracic space available for lung growth.

Intrathoracic causes include:

Extrathoracic causes include:

Other associations include:

Radiographic features

Ultrasound

Antenatal ultrasound may show ancillary features such as the presence of oligohydramnios and/or also show any of the causative anomalies.

Several sonographic parameters may give indirect clues as to the presence and extent of pulmonary hypoplasia. Such include:

  • fetal lung : head ratio: reduced (ratios <1 usually indicate a poor prognosis)
  • fetal chest circumference (or thoracic circumference (TC)) : reduced

(In the case of intra-thoracic causes, both these parameters can be normal)

  • thoracic : abdominal circumference ratio <0.6
  • femur length : abdominal circumference ratio <0.16
Doppler

Peripheral pulmonary arterial resistance is often increased with pulmonary hypoplasia.

MRI

Fetal MRI may be useful to more accurately calculate lung volumes:

  • T1:  normal fetal lung is usually low signal on T1; more to be added
  • T2:  normal fetal long is usually high signal on T2; more to be added
  • HASTE:  fetuses with pulmonary hypoplasia are thought to have low signal

Treatment and prognosis

The presence or development of pulmonary hypoplasia is often a critical determining feature in fetal survival in context of other potential causative anomalies. Treatment will significantly depend on the presence of underlying/associated anomalies.

Differential diagnosis

In adult cases of unilateral pulmonary hypoplasia, consider conditions associated with a small hemithorax such as:

See also

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Lungenhypoplasie:
Scimitar-Syndrom
 
Wikipedia • CC BY-SA 3.0
Poland-Syndrom
 
Wikipedia • CC BY-SA 4.0
Pulmonalatresie
 
www.eurorad.org • CC by-nc-sa-4.0
Swyer-James-Syndrom
 
Wikipedia • CC-BY-SA-3.0
pulmonale
Aplasie
pediatricimaging.org • CC-by-nc-sa 4.0