2. Introduction
Normal neonatal chest
Respiratory distress syndrome
Transient tachypnoea of the newborn
Meconium aspiration syndrome
Neonatal pneumonia
Mechanical ventilation
Lines and tubes
Conclusion
3. Introduction
• Close collaboration between neonatologists and radiologists is the key in achieving the correct
diagnosis, since the radiographic features of many lung disorders overlap and the findings on the chest
film can be rather subtle.
• Clinical information like age of the neonate, gestational age and therapy with ventilation or surfactant
is vital for the interpretation of the radiological findings.
• Preterm infants show different types of pathology compared to term infants.
• For example, respiratory distress syndrome (RDS) is almost exclusively seen in preterm infants.
• Meconium aspiration (MA) on the other hand, is seen in full term or late term neonates in combination
with meconium-stained amniotic fluid during labor.
Invasive mechanical ventilation and surfactant therapy will have a huge impact on the radiographic findings
and are essential clinical information for the radiologist.
Plain radiography is still very important in the management of newborn babies, especially in premature
babies.
4. • The approach to the neonatal chest film starts by looking at the technique of the
radiograph.
• Then the position of lines and tubes is analyzed.
After these steps, the chest film can be interpreted for pathology.
This is done in a stepwise manner:
Consider gestational age, postnatal age, and other clinical information, including
respiratory support.
Lung volume should interpreted, being either normal, hypo-inflated or hyper-inflated.
Interpretation of lung parenchyma, being either normal, lucent, or opacified.
Pathology unilateral or bilateral.
Rotated chest X-ray may simulate cardiomegaly or hyperdense hemithorax (image on the left).
New X-ray study in the same patient reveals no cardiopulmonary disease (image on the right).
5. Normal Neonatal Chest
Sternal ossification centre may simulate healing rib
fractures or lung opacities
The normal cardiothoracic ratio can be as large as
65% due to the presence of the thymus.
Air bronchograms may be present
CXR signs of a premature infant:
Lack of subcutaneous fat
Lack of humeral ossification centres
Usually an ETT is present
Radiograph showing the sternal ossification
centres simulating healing rib fractures
(arrows)
Bilaterally reduced lung volume. Diffuse symmetrical
reticulogranular densities involving all lung fields. NG
tube seen in an appropriate position. The ossification
centers of both humeral heads are not visualized
suggestive of prematurity.
6.
7. Normal chest: Skin folds
Skin folds are the most common artifact
seen in newborn infants’ x-rays.
Especially common in premature infants
and results from the folding of excessively
redundant skin.
Often misinterpreted as pneumothorax
o Line produced by a skin fold travels across, and
outside the chest or across the diaphragm into the
abdomen
o Lack of visualization of vascular markings lateral to
the edge of the collapsed lung, and at the same
time, this space should be very black
Vertical skin fold versus pneumothorax
A. Skin fold. Vertical orientation of the skin fold.
B. True pneumothorax. Near-vertical orientation of
the edge of the compressed lung. No lung
markings are seen lateral to the edge of the lung.
In A, even though hyperlucency lateral to the skin
fold is present, lung markings still are visible beyond
the line of the skin fold.
8. Large left sided curvilinear line from left apex to left
mid-zone. No lung markings visible peripherally.
Slightly atypical for pneumothorax, given the cranial
outline extends to midline (and across vertebral
bodies).
Child was well. Oxygen saturation is 99% on room air.
Likely skin fold.
Repeat examination after the baby was repositioned.
The line has disappeared and there is definitely no
pneumothorax.
10. Respiratory Distress Syndrome (RDS)
• RDS is also known as hyaline membrane disease (HMD), idiopathic respiratory distress syndrome (IRDS)
and surfactant deficiency disorder (SDD).
• SDD is the most common cause of respiratory distress and death in pre-term infants.
• It is caused by insufficient surfactant (due to immature type II pneumocytes) and resultant decreased
lung compliance.
• Greater than 95% of cases are seen in pre-term infants born before 34 weeks.
• Less commonly, term babies born to diabetic mothers or via Caesarean delivery have increased
prevalence of SDD.
• Oxygen requirements progressively increase over the first few hours after birth.
• The treatment of RDS generally includes positive pressure ventilation and may include intratracheal
surfactant replacement.
11. Imaging
• Decreased lung volume on chest radiograph unless the patient is on ventilator.
• Bilateral symmetric ground glass opacities.
• Air bronchograms can be visible into the periphery.
• Poor definition of the cardiac silhouette and pulmonary vessels, as a result of less aerated lung
parenchyma.
• Usually no pleural effusion.
• Radiological appearance can be asymmetric immediately after minimally invasive surfactant therapy
(MIST) and can mimic for example neonatal pneumonia.
In many preterm neonates improvements in
treatment, including antenatal glucocorticoid
administration, surfactant replacement therapy
and better ventilatory strategies have decreased
the prevalence of RDS.
When prolonged mechanical ventilation is
necessary, this increases the risk of lung injury
and air leak and can evolve into chronic lung
disease.
12. 33 weeks + 5 days gestational age, day one.
Findings:
• Intubated patient.
• Good position of endotracheal tube (ETT).
• Hyperinflation.
• Symmetric granular opacifications with air
bronchograms.
• Definition of heart and vessels is diminished.
This is a typical case of RDS.
29 weeks + 1 day one. CPAP.
Findings:
• Reticulogranular opacification of lungs
• Air bronchogram
• Consolidation in the right lower lobe
• Heart, vessels and diaphragm are poorly defined.
• Malposition of umbilical vein catheter (arrow),
probably in a pulmonary vein.
• Nasogastric tube (NG tube) in good position.
This is a severe case of RDS.
The differential diagnosis includes pulmonary
infection due to the asymmetric consolidation.
13. Grading
• Grading of RDS can be performed but is not used when the patient is on invasive mechanical ventilation
support.
• As the lungs cannot expand properly in RDS, hyperinflation in a preterm infant without mechanical ventilation
makes the diagnosis of RDS highly unlikely.
• There are 4 grades of staging RDS.
1) Only mild ground glass or mild granular opacification of the lungs.
2) Granular opacification with air bronchograms.
3) Increasing consolidation of lung tissue leading to obscured borders of the heart and diaphragm.
4) Complete pulmonary white-out.
One week old neonate, born at 27 weeks of gestational age.
Image
Deep position of the tracheal tube, which should be
repositioned to the mid of the trachea.
Diffuse granular opacification of both lungs.
Air bronchograms.
Pulmonary vessels are not recognized anymore, but cardiac
silhouette is still recognizable.
Opacification of the left lower lobe caused by atelectasis.
No grading because this neonate is on mechanical ventilation.
14. One day old neonate, 27 weeks of gestational age.
Image
• Granular opacification of both lungs.
• Vessels and cardiac silhouette are well depicted.
Conclusion: RDS grade 1.
Peripherally inserted central catheter (PICC) line, curled in the right
atrium. The PICC should be pulled back to the level of the superior vena
cava and right atrium.
One day old neonate, 29 weeks of gestational age.
Image
• Hyperinflation due to CPAP.
• Granular opacification of both lungs with air bronchograms.
• Vessels and cardiac silhouette are harder to distinguish.
• NG tube in good position.
Conclusion: RDS grade 2.
15. One day old boy, gestational age 25 weeks and 5 days.
Image
Grade 4 RDS with complete opacification of left lung and right
upper lobe.
After one bolus of surfactant the right lower lobe and the
middle lobe are aerated.
Good position of ETT and umbilical artery line.
Malposition of the umbilical vein line in the portal vein. This
should be removed.
One day old neonate, 26 weeks of gestational age.
Image
• Granular opacification of both lungs.
• Vessels and cardiac silhouette are hard to distinguish.
• Umbilical venous line properly positioned.
• Deep position of umbilical artery line, which should be pulled
back to the level of T6.
• NG tube in situ.
Conclusion: RDS grade 3.
16. Transient Tachypnea of the Newborn (TTN)
• Transient Tachypnea of the Newborn (TTN) is also known as wet lung or retained fetal lung liquid.
• TTN is the most common cause of respiratory distress in neonates (full term).
• It is caused by lack of clearance of fetal lung fluid by prostaglandins, which normally dilate pulmonary
lymphatics to absorb excess fluid.
• Prostaglandin imbalance can be worsened by male sex, Caesarean delivery (lack of “vaginal squeeze”),
or maternal asthma, diabetes or sedation.
• Symptoms of dyspnea usually occur during the first 6 hours, peak at 24 hours and resolve by 48–72
hours.
17. Imaging
• Mild increased lung volume.
• Interstitial edema resulting in perihilar linear
densities.
• Subtle enlargement of the cardiac silhouette.
• Pleural effusions and fluid in the fissures.
• The radiological findings may be asymmetrical.
In many cases the clinical presentation is mild and there is no need for a chest radiograph.
Only in some cases a chest x-ray is performed to rule out complications.
The imaging findings may be similar to those of RDS, showing diffuse granular opacities, or of pneumonia
with more coarse opacities.
18. Full term infant, 2 hours after elective caesarean
section with some respiratory distress.
Findings:
• Mild hyperinflation
• Subtle interstitial linings on both sides
• Some pleural fluid on the right side (arrow).
• Skin fold on the right side
After supportive therapy the respiratory distress
disappeared the next day.
41 Weeks neonate. 24 hours old.
Respiratory distress, no ventilatory support
Findings:
• Marked hyperinflation of both lungs
• Increased vascular markings and interstitial
markings
• Some inter-fissural fluid (arrow).
Spontaneous improvement within 48 hours.
19. Meconium Aspiration
• Meconium aspiration results in diffuse pulmonary disease and it is the most common cause of
significant morbidity and mortality among full-term and post-term neonates.
• This occurs when infants who suffer a hypoxic stress in utero pass meconium into the amniotic fluid,
which is then inhaled results in a chemical bronchiolitis with obstruction of the smaller airways and
surfactant dysfunction resulting in air trapping and atelectasis.
• Meconium aspiration can impede the transition from prenatal fetal circulation to postnatal neonatal
circulation.
• Usually, this condition presents within a few hours after birth.
20. Imaging
• Increased lung volume due to air trapping.
• Bronchiolitis can lead to atelectasis and air trapping.
• Complete obstruction of the bronchus can lead to atelectasis.
• Coarse, diffuse bilateral patchy or more linear opacification.
• Can present asymmetrical.
• Pleural effusions can be seen.
• In a later stage persistent pulmonary hypertension present as cardiomegaly on the x-ray..
21. Chest film of a full term newborn with meconium
stained amniotic fluid.
Findings:
• Hyperinflation
• Course diffuse patchy consolidations on both sides.
• Some subtle pleural fluid on both sides
(arrowheads).
• Good position ETT. Superficial position NG tube, still
in esophagus.
• Deep position of umbilical vein line with tip in right
atrium.
Chest film of a full term newborn with meconium
stained amniotic fluid.
Findings:
• Good position of ETT, NG tube and umbilical vein
line.
• Course patchy consolidations with relative sparing
of the left apical lobe and right middle lobe.
• Mild hyperinflation.
Conclusion: chest radiograph in keeping with
meconium aspiration.
Without staining of the amniotic fluid the differential
diagnosis would include neonatal pneumonia or TTN.
22. Neonatal Pneumonia
• Neonatal pneumonia refers to inflammatory changes of the respiratory system caused by neonatal
infection.
• In the majority of cases the clinical course, together with intratracheal sputum cultures and biochemical
parameters are leading in the diagnosis of pneumonia.
• Without signs of infection, a consolidation on a chest radiograph is unlikely to be caused by pneumonia.
• Typical signs of adult pneumonia, such as fever or elevated white count, are not reliable in neonates.
Therefore, it can be difficult to distinguish between neonatal pneumonia and TTN.
Risk factors for neonatal pneumonia are:
• Preterm infants with ventilatory support and intubation.
• Full-term newborns after prolonged rupture of membranes or after maternal infection.
• Secondary after meconium aspiration.
• Transplacental (TORCH) infections - (Toxoplasmosis, Rubella, Cytomegalovirus and Herpes)
• Perinatal infection, such as E. coli or group B streptococcus, viral. Miscellaneous agents as Chlamydia
trachomatis can be found.
23. Imaging
• Hyperinflation of both lungs
• Multifocal irregular opacities are observed in both
lungs with cavitations (small arrows).
• Right pleural effusion (long arrow) is evident
obliterating right costophrenic sulcus
Staphylococcus aureus pneumonia.
24. Neonate, GA 37+6 weeks, respiratory distress, treated
with CPAP after delivery. History of maternal infection.
Findings:
• Bilateral increased lung volume with asymmetric
increased opacification of the lungs with subtle
consolidation of right upper lobe (black arrow) and
left lower lobe (white arrow).
• Hyperinflation of left upper lobe.
This child developed signs of infection, both clinically
and in the laboratory findings.
The radiographic findings were attributed to neonatal
pneumonia.
A full term neonate, with respiratory distress after 24
hours.
Findings:
• Hyperinflation of both lungs and cardiac
enlargement with increased interstitial markings
and vascular markings. No pleural fluid.
The differential diagnosis includes TTN and neonatal
pneumonia.
After 48 hours there was no improvement of the
respiratory distress, and the neonate developed signs
of infection.
25. Mechanical Ventilation
Early effects of mechanical ventilation
• Air leak: a premature infant’s lungs are immature and vulnerable to damage with alveolar rupture
leading to various air leak complications:
• Air leakage as a result of barotrauma in newborns present as:
Pneumothorax
Pneumomediastinum and pericardium
Pulmonary Interstitial Emphysema (PIE)
Tracheal rupture
Pneumatocele
26. Pneumothorax
• Pneumothorax can occur spontaneously or as a complication of positive pressure ventilatory
support.
• The introduction of surfactant treatment and improved ventilatory support has significantly
decreased the incidence.
Neonate 32 weeks gestational age. Treated for RDS
via CPAP, with sudden respiratory distress.
Image
There is a pneumothorax on the right side.
Midline structures are displaced to the left.
The left lungs shows reticulonodular markings in
keeping with RDS.
27. Pneumomediastinum
• Pneumomediastinum is recognized as air inside the mediastinum.
• The classical sign is the so-called spinnaker sign (arrowhead). This is caused by the thymus
being ‘lifted up’ from the lower mediastinum by mediastinal air.
Normal Thymic Sail Sign. The triangular density to the
right of the mediastinum is bounded inferiorly by the
major fissure and the density is NOT separated from
the mediastinum by air.
Spinnaker Sail Sign. This is abnormal. The right and
left lobes of the thymus are displaced off of the
mediastinal structures by air in the mediastinum. The
thymus looks like the spinnaker sails of a ship
28. Pulmonary Interstitial Emphysema (PIE)
• PIE is leakage of air into the perivascular and peribronchial spaces as a result of rupture at the
bronchio-alveolar junctions.
• PIE is recognized as either small bubbles or linear air collections along the bronchovascular
bundle radiating from hilum to the periphery.
• PIE can be bilateral or unilateral.
Preterm infant born at 27 weeks gestational age.
Now 6 weeks old. Mechanical ventilation for RDS.
Image
Bubbly air configurations bilateral indicating PIE.
Deep position umbilical vein line, tip likely in left
atrium or pulmonary vein.
Good position ETT. NG tube in situ..
29. Neonate 3 days old with RDS. Gestational age: 34 weeks.
Findings:
• Increased lucency of the right pleural space.
• Increased density of the partially collapsed right lung.
• Mediastinal shift to the left as a result of the
pneumothorax under tension.
• Pneumomediastinum causing ‘lifting’ of the thymus.
Neonate 1 days old with RDS, gestational age 30 weeks.
Findings:
• Bilateral radiating bubbly lucencies, with
hyperinflation of both lungs.
• These are typical findings in PIE.
30. Bronchopulmonary Dysplasia
Late effects of mechanical ventilation
• Bronchopulmonary dysplasia (BPD) also known as chronic lung disease of the premature, is a disorder
of lung injury and repair originally ascribed to positive-pressure mechanical ventilation and oxygen
toxicity.
• BPD is nowadays a purely clinical diagnosis characterized by the requirement of oxygen for at least 28
days in an infant born at less than 30 weeks of gestation.
• Nowadays after the introduction of prenatal steroids and postnatal surfactant and more sophisticated
ventilatory support, BPD is infrequently seen in infants.
31. Premature, born at 27 weeks of gestational age.
Now 6 weeks of age.
History of intubation and mechanical airway support.
Findings:
• Bilateral perihilar opacification and increased
interstitial markings.
• Given the history, BPD is the most likely diagnosis.
Premature, born at 27 weeks of gestational age.
Now 8 weeks of age.
History of extensive mechanical ventilation with
prolonged need for oxygen support.
Findings:
• Bilateral perihilar opacifications with a coarse
interstitial pattern as a sign of chronic small airway
disease.
• NG tube in situ.
• Given the history in combination with the radiological
findings BPD is the most likely diagnosis.
33. Lines and tubes in Neonates
Umbilical artery line
• Umbilical artery catheterization provides direct
access to the arterial system and allows
accurate measurement of arterial blood
pressure, blood sampling and intravascular
access for fluids and medications.
• The catheter should be passed through the
umbilic artery and enter the aorta via the
internal iliac artery.
• It should demonstrate the typical loop from the
umbilicus inferiorly into the internal iliac artery.
• In order to avoid placement into aortic
branches, the catheter should be either in a
high position above the celiac, mesenteric and
renal arteries or in a low position below the
inferior mesenteric artery:
• high position: T6-T9
• low position: L3-L5
• The high position is advisable since it leads to
less vascular complications .
34. Findings:
• Umbilical artery line in a good high position.
• Malposition of umbilical vein line in right portal
vein.
Findings:
• Malposition of umbilical artery line in left iliac
artery.
• Deep position of umbilical vein line in right atrium.
• Good position of gastric tube.
35. Lines and tubes in Neonates
Umbilical vein catheter
• An umbilical vein catheter should pass through the
umbilic vein into the left portal vein.
• Then through the ductus venosus into a hepatic
vein and the inferior caval vein (IVC).
• The tip should be positioned in the IVC at the level
of the diaphragm.
• Several line malpositions are possible:
• Low position in the umbilical vein. Not all
medication can be administered through a line
in this position.
• Intrahepatic into the portal venous system,
both right and left, or even into the superior
mesenteric or splenic vein. This can cause
thrombosis.
• Perforation of the portal vein can cause
haemorrhage or abscess formation in the liver.
• Position too deep in right atrium or in the left
atrium through a patent foramen ovale or atrial
septal defect. This can lead to cardiac
arrhythmias or perforation.
36. Findings:
• The tip of the umbilical vein line is pointed downwards and
probably situated in the mesenterical vein.
Findings:
• The umbilical venous line is too deep and positioned in the
right atrium.
• The umbilical arterial line is at the level of T10 (preferrably
at level T6-T9).
• The endotracheal tube is positioned too deep. It should be 1
cm above the trachea bifurcation.
Findings:
• The umbilical venous line is too deep.
• The line probably went through a patent foramen ovale and
through the left atrium into a pulmonary vein.
Findings:
• The umbilical venous line is too deep
• After repositioning the tip is in a good position. Notice that the endotracheal tube is too deep.
37. Lines and tubes in Neonates
Endotracheal tube
• The tip of an endotracheal tube should be in
between the thoracic aperture and 1 cm above the
carina.
• The tip travels downward if the neck is flexed or
upward if the neck is extended.
• The most common mal-positioning is in the right
mainstem bronchus, because of the shallower angle
of the right main bronchus.
Findings:
• A good positioned tube in a patient with a
pneumothorax on the left.
38. Findings:
• Right mainstem bronchus intubation with atelectasis of the
entire left lung.
Findings:
• Endotracheal tube is positioned in the right main bronchus.
• Atelectasis of left upper lobe of the lung.
Findings:
• Endotracheal tube is positioned in the oesophagus.
• Chest radiograph shows dilatation of the esophagus and
stomach, that are filled with air (arrows).
39. Lines and tubes in Neonates
Peripherally Inserted Central Catheter
• A peripheral inserted central catheter or PICC line is
positioned in the great vessels, preferably in the
superior or inferior caval vein.
• It is important for the neonatologist to know if the
line is in a superficial position, because then not all
medication can be given.
Findings:
• Malpositioned PICC line. Probably located in the
coronary sinus or in the left atrium after passing
through a patent foramen ovale.
Reploggel's suction catheter
• Replogle's suction catheters are used in case of
oesophageal atresia to remove saliva.
• They are positioned in the blind ending oesophagus.
• The markings of a Replogle's suction catheter form a
dashed line.
Findings:
• There is a Reploggel's drain in situ.
• Notice deep position of endotracheal tube and
atelectasis of left upper lobe.
40. Conclusion
• Multiple processes can cause respiratory distress in a neonate, including
pulmonary disease, congenital heart disease, thoracic mass, airway disorders,
skeletal abnormalities, vascular anomalies, etc.
41. References
• Grainger & Allison’s, Diagnostic radiology, Textbook of medical imaging
• Grainger & Allison’s, Diagnostic radiology essentials, Second edition
• https://radiologyassistant.nl/pediatrics/pediatric-chest-ct/neonatal-chest
• https://radiologyassistant.nl/pediatrics/abdominal-masses/lines-and-tubes-
in-neonates
