Pediatric chest xray

Basics of interpreting neonatal and pediatric chest Xrays

1. CHEST X-RAY
–The Basics

2. A TEN-POINT CHECKLIST
Is it a PA or AP radiograph?
Is it a satisfactory inspiration?
Is the patient rotated?
Is the heart enlarged?
Are both domes of the diaphragm clearly seen and well-
defined?
Are the heart borders clearly seen and well-defined?
Are the hila normal…position, size and density?
Are the bones normal?
Check the tricky hidden areas
Have the patient’s particular clinical problem been addressed

3. TECHNIQUE
In order to reduce the radiation dose for neonates, only
one AP view of the chest should be taken initially
In the first radiological examination, it is advisable to
include abdominal imaging as well
Presence of air in bowel loops
Ruling out of abdominal diseases to cause respiratory
symptoms
In subsequent x-rays, lateral chest and abdomen views
only can be included when there is clinical indication

4. Age Projection Patient position
Under 3 months Antero-posterior Supine
3 months to 4
years
Antero-posterior Erect
4 years and older Postero-anterior Erect
Guide to common practice for pediatric
chest radiography

5. CHOICE OF PROJECTION
No difference in the diagnostic value of AP compared to PA
projection in <4 years of age as the thoracic cage is
essentially cylindrical in young children and magnification of
mediastinal organs is insignificant
However, AP projection is associated with a higher radiation
dose to the developing breast, sternum and thyroid
In children under 4 years of age, the AP projection is often
preferred due to ease of positioning, immobilisation and
maintenance of patient communication
Disadvantage of AP projection is the likelihood of lordosis
but this can be prevented by careful technique

6. AP-SUPINE
A 15°foam pad for use in
chest radiography. The cut
out area helps to prevent the
chin obscuring the upper
chest
Correct supine chest technique. Note
the use of a 15°foam pad and arms
positioned with elbows flexed to prevent
hyperextension of the spine and lordosis

7. AP -ERECT
The child is seated on a foam sponge
and a 15°pad is placed behind the
chest to reduce lordosis. The arms are
held flexed at the side of the head by
a suitably protected guardian

8. Radiographic assessment criteria
1. Area of interest to be included on the radiograph
The radiograph should include the whole of the chest
from, and including, the first rib to the costophrenic
angles inferiorly and the outer margins of the ribs
laterally
Should also inculdebilateral clavicles and head of
humerusto look for ossification centres
Adequate centralization of the central beam on the
thoracic cage

10. 2. Assessment of inspiration on a chest radiograph:
Chest with trapezoidal morphology
Ribs horizontally disposed and parallel to each other
Cardiophrenicsinuses well delineated
Anterior arch of 6
th
rib projected over diaphragm
Supraclavicular fossasand superior hemiabdomen
included

12. Age of child Optimum inspiration
0–3 years 6 anterior ribs, 8
posterior ribs
3–7 years 6 anterior ribs, 9
posterior ribs
8 years + 6 anterior ribs, 10
posterior ribs

13. Pulmonary hypoaeration:
Results in horizontalizationof costal arcs, false
widening of the cardiothymicsilhouette and reduction
of the pulmonary transparency with possibility of
simulating pulmonary edema, hemorrhage, atelectasis
and pneumonic consolidations

14. Inspiratory Effort

15. 3. Rotation:
Vertical line drawn through the centre of the vertebral bodies
(T1–T5) equidistant from the medial end of each clavicle
Rotation is present when one of the clavicles is further away
from this vertical line
The chest of a young child is more cylindrical than that of an
adult and therefore a small amount of rotation will lead to the
appearance of significant asymmetry
Due to difficulties in visualisingthe medial ends of the clavicles
in young children, rotation is better judged using the anterior
ribs, which should be of equal length and symmetrically
positioned with respect to the vertebral column.

16. Rotated AP chest x-ray of a newborn
infant demonstrating bilateral clavicles
and costal arcs asymmetry

17. Rotated postero-anterior projection.
Note the unusual cardiac outline and the
asymmetric appearance of the anterior
ribs

18. •RotatedchestX-raymaysimulatecardiomegaly
orhyperdensehemithorax
•NewX-raystudyinthesamepatientrevealsno
cardiopulmonarydisease

19. 4. Lordosis:
Lordosisis a common technical fault inadequate
centralization of the central ray over the neonate’s
abdomen when performing antero-posterior chest
radiography and may be resolved by placing a 15°pad
behind the patient’s
Radiographically, lordosiscan be identified when the
anterior ribs appear horizontal or are angled cranially to
lie above the posterior ribs,
Widening and distortion of the cardiothymicimage

20. Lordotic antero-posterior projection. Note
that the anterior ribs cephalad in relation
to posterior ribs

21. 5. Exposure:
Visualization of dorsal intervertebral spaces through
the cardiac silhouette
Pulmonary vessels in the central two-thirds of the lung
fields without evidence of blurring
The trachea and major bronchi should be visible through
the heart shadow

22. X-ray beam underpenetration: Reduces the density
differences between intrathoracic structures and
simulating false pulmonary opacities
X-ray beam overpenetration:Darkens the
radiographic film and possibly concealing pulmonary
opacities, mainly the most subtle ones, like interstitial
opacities like TTN or HMD

23. Overexposed Underexposed

24. NORMAL CXR

25. THE HEART
CXR evidence of cardiac enlargement
On an infant’s AP radiograph the normal cardiothoracic
ratio (CTR) should not exceed 60%
On a child’s PA radiograph the normal CTR can be
slightly above 50%, though by the second year it rarely
exceeds 50%

26. 6 months old. The initial impression is
that the heart is enlarged. But…this is
an AP CXR. The CTR does not exceed
60%. There is no reason to suggest
cardiac enlargement

27. HILA
99% of each hilar shadow is due to vessels —pulmonary
arteries and to a lesser extent veins.
Minor contribution from fat, lymph nodes, and bronchial walls
The superior margin of the left hilum is normally higher than
the right.
This is because the left main pulmonary artery passes over
the left main bronchus whereas the right main pulmonary
artery passes in front of the right main bronchus
The hila are at the same level in 5% of normal CXRs
The important rule: The left hilum should never be lower
than the righ

29. MEDIASTINUM

31. BLIND SPOTS
Behind heart & hemidiaphragms
Lung apices
Costophrenic angles
Hila
Rib lesions
Shoulders

32. NORMAL STRUCTURES
35 weeks gestation.
One day old. Mediastinum widened
to the right and to the left
Four weeks old. AP view
The rounded shadow projected
over the right upper zone

33. THYMUS
The thymic shadow is visible at birth
Characterized by a widening of the upper mediastinum, above the
cardiac image, on the AP view, and an increase in the supracardiac
retrosternal density on the lateral view
On the AP view, the normal width of the thymic image must be higher
than double the width of the third thoracic vertebra
Shorter dimensions represents sign of thymic involution
When a child is ill or under stress, thymic shadow may decrease in size
Involution may revert once the stress situation is overcome, and the
thymus returns to its normal dimensions
The gland normally involutes between the ages of two and eight years
Rare for the thymic shadow to be evident on the CXR after the age of
eight years

35. Sail sign-lateral triangular soft
tissue opacity
Wave sign-indentation of the
lateral borders of thymus by
anterior costochondral junctions
Notch sign-the inferior border
of the normal thymus blends with
the border of the cardiac
silhouette

37. Other Normal Findings
Transitory cardiomegalymay be noted during the first
hours of a neonate’s life, as a result of additional blood
inflow from the placenta into the umbilical cord before
its cutting, and of the presence of a bidirectional shunt
through the arterial duct and oval foramen
Prominent pulmonary vascularizationmay be observed
as a result of residual lung fluid absorption through the
lymphatic-venous system
Open ductus arterial canal may be seen on a chest x-ray
as a convex prominence to the left of the spine,
between T3 and T4 vertebras, this configuration being
denominated ductus bump

38. One-day-old newborn infant chest x-ray
demonstrating the ductus bump (arrow)

39. Other Normal Findings …..(cont.)
The thickness of the thoracic wall soft tissues reflects
the nutritional condition, and may be decreased in LBW
neonates
Secondary ossification nuclei of the proximal humeral
extremity and coracoid apophysis may be visualized
indicating sign of fetal maturity
Typically, the presence of air may be observed in the
stomach right at birth, small bowel with three hours of
live, and in the rectum, six to eight hours after birth

40. ARTEFACTS
Skinfold-
pneumothorax; dense,
linear image
presenting an
obliquity as opposed
to the lung border,
extending below the
thoracic cavity

41. Hole in incubator-
lung cyst,
pneumatocele

42. TUBES AND LINES

43. UMBLICAL VEIN CATHETER
UVC tip (arrow) good position
in the IVC.
UVC. Incorrect position.
The tip (arrow) of the catheter has
entered a portal vein and lies within the
right lobe of the liver

44. UMBLICAL ARTERY CATHETER
UAC in good (high) position. The tip
(arrow) lies above the dome of the
diaphragm (at the level of
the T7 vertebra)
The tip (arrow) of the UAC is too
low—it lies at the level of L2
vertebra, close to the origins of
the renal arteries

45. CENTRAL VENOUS LINE
Right subclavian line in good position with its tip in the SVC. The SVC
commences at the level of the right 1
st
anterior intercostal space

46. Left ante-cubital long line.
Unsatisfactory position.
The tip (arrow) lies within the
right atrium. Dysrhythmia is a
recognised complication
The subclavian line has entered the
internal jugular vein

47. ENDOTRACHEAL TUBE
ETT. Satisfactory position.
Approximates to the level of the
medial ends of the clavicles.
1.5-2cm above carina when the head
is held in the neutral position
ETT in the oesophagus.
The tip (arrow) of the ETT is midline
but well below the carina; the
distended and air filled stomach

48. ETT in the right main bronchus.
This has caused complete
consolidation of the non-ventilated
left lung
ETT has entered the right main
bronchus. Lung collapse has
not yet occurred

49. TRACHEOSTOMY TUBE
Tracheostomy tube walls lie
parallel to the long axis of the
trachea.
Tip lies several centimetres above
the carina.
The infated cuff should not bulge
the lateral walls of the trachea.

50. NASOGASTRIC TUBE
NG tubes
(a) Normal position
(b) Tip in the
oesophagus.

51. CONCLUSION
PROPER AP CXR:
1.Visualization of dorsal
intervertebral spaces through
the cardiac silhouette
2.Right hemi-diaphragm at the
level of the anterior arc of the
6
th
rib
3.Caudal inclination of anterior
costal arcs appearing
underneath the posterior ones
4.Symmetry of bone structures
on both sides of the thoracic
cage

52. THANK YOU