Paediatric Radiology

This session was designed to help you feel more confident interpreting paediatric imaging.

You should already have a basic understanding of interpreting imaging from your Foundations of Clinical Practice. We will recap how to approach interpretation in a structured manner.

By the end of this session, you should be able to identify common abnormalities on imaging that is related to your core conditions.



Quality of Imaging

Why is the quality of imaging important?

Influences the interpretation of the imaging.

For example, you may miss a broken bone if the field of view is too small. Or you may miss a pneumonia if there's not adequate penetration.

Image quality if made up of the following:

  • Inclusion
  • Projection
  • Rotation
  • Penetration


Inclusion refers to the area of the image.

For example, a good chest xray should show the entire thoracic cage.

  • At the top you should be able to see the first rib.
  • At the bottom you should see the costophrenic angles.
  • At the lateral sides, you should clearly see the rib edges.

An abdominal xray should show the abdominal cavity from the diaphragm all the way down to the hernial orifices. This may fit into one image in young children or atleast 2 different xray films in older children.

This is a poor quality field of view.


This is an example of adequate inclusion. All the important sites can be seen.

See how you can see the costophrenic angles?


For chest xrays there are two main projections you need to know: AP and PA

Most chest X-rays are done PA and this is the projection you should use when commenting on heart size. AP view can make the heart appear larger than it is, but if the heart is still a normal size in AP view, then you can still say that there is no cardiomegaly.

Another projection you may come across is lateral. This is viewed from the side and allows you to "see behind the heart" where a pneumonia might be hiding.

Most bone rays are done in two projections, usually at different angles so you can safely exclude a fracture.

This is an example of an AP film.

It is usually done if the patient is unwell and cannot be taken to the xray department. You might see additional labels on the film such as "resus" which means the patient is in resus in a&e or "supine" where the patient is in bed.

This is an example of a PA film. 

This is the ideal chest xray standard


Next you should check to see if the film is rotated. 

The spinous processes should form a vertical line that is equidistant from the clavicles. This is the easiest way to check for rotation.

It is important to have a film that is not rotated so you can assess for tracheal deviation. It can also make it difficult to see the costophrenic angles to assess for effusion. As you can imagine, it may also make the heart size look larger if the patient is tilted to the left and smaller if tilted to the right.

Sometimes a film may look rotated if the patient has scoliosis. But if you know the patient history, and check the rotation using the method above, you should still be able to tell that the spine is curved rather than the xray rotated.

Does this image show a rotated film? or scoliosis? or both?


Penetration is the degree to which the xrays have passed through the body. An ideal chest xray is where the vertebrae should just be visible behind the heart.

If the film is under-penetrated, the lung tissue behind the heart cannot be assessed. 

However, you can use the PACS software to "re-window" and change the exposure of the image to help you see better.

This is an example of the image above if it had been under-exposed.

It is much harder to interpret.

This is the same image again but over-exposed.

The radiographers try to get an ideal xray film like the one above but sometimes they don't always manage.

Chest X-rays

Reminder of normal chest anatomy

Structure of Interpretation

When describing what you see in a radiology film, it is best to stick to a structure but make sure to describe the obvious abnormality too!

A useful one to remember is A, B, C, D, E

Describe the abnormalities before you come to a conclusion on a likely diagnosis like pneumonia/pleural effusion.


Look at the trachea.

Is it deviated?


Look at the lung fields.

Are there lung markings?

Are they clear?

Describe any lesions

  • Location in terms of zones, not lobes
  • Patchy/diffuse/well defined?
  • Size
  • Use terms like shadowing/opacification/consolidation

Is there any abnormality in the pleural space? 

Are the costophrenic angles visible? Effusion?


Look at the heart and the hilar structures.

How big is the heart compared to the thorax? Normal is less than 50%

Is there any hilar prominence?

Structure of Interpretation


D= Dem Bones!

Look at the bony structures. 

Look at the clavicles and the ribs. Sometimes the humerus is also visible.

You're looking for any fractures or breaks in the bones but you're also looking for any increased density suggestive of metastatic disease, although uncommon in paediatrics

E= Equipment/Everything else

Lastly, is there any additional equipment?

Any NG tubes?

Oxygen tubes?

Foreign body even...

Abdominal X-rays

Normal Abdominal Anatomy

Structure of interpretation

Abdominal xrays are not the best mode of imaging for the organs in the abdomen. Ultrasound is usually your first port of call. Even chest xrays can be useful to assess if there's air under the diaphragm. This is an important consideration as the radiation exposure from abdominal xrays is much more than from chest xrays. However, it can be a useful tool in assessing for abnormal patterns of bowel gas.

Remember the differences between large bowel appearances and small bowel appearances.

Large bowel have folds called haustrations which don't go all the way across the bowel whereas small bowel has valvulae conniventes which are lines going all the way through.

Remember the 3 6 9 rule for adults

3cm small bowel

6cm large bowel

9cm caecum

Anything larger than this is abnormal!

In children, their organs are smaller so there Is no hard and fast rule. As you can imagine, the numbers would just keep changing based on their age and size.

Also remember that the causes of obstruction are different:

  • volvulus
  • atresia
  • intussusception (usually use ultrasound to diagnose)
  • pyloric stenosis (usually use ultrasound to diagnose)
  • hirschprung disease (use xray with contrast to diagnose)
  • necrotising enterocolitis

Bone X-rays

Normal Bone Anatomy

Structure of interpretation

You might be different areas of the body imaged for fractures.

You should describe any abnormalities you see.

Describe the location... mid shaft/distal/proximal... femur/humerus/tibia/etc...

Describe the type of fracture.

Describe whether the fracture is complete (travels the whole way across the bone) or incomplete and if complete, describe whether it is displaced or nondisplaced based on if the fracture segments have moved.

Transverse fractures go straight across the bone. They don't always go all the way across.

Linear fractures travel in the same direction as the bone.

Comminuited fractures are where there are multiple fragments of bone and usually occur after high impact trauma such as a road traffic accident.

Spiral fractures are caused by rotational forces and are usually uncommon. You should rule out non-accidental injury with spiral fractures.

However greenstick fractures are common in paediatrics. It is due to young soft bone bending and then breaking.

Epiphyseal fractures are another common fracture which is found in up to 15% of childhood long bone fractures. They occur at the epiphyseal(growth) plate. Remember to use the SALTER-HARRIS classification if you see an epiphyseal fracture.

CT Head

Normal Head Anatomy

Structure of interpretation

The denser the material, the whiter it appears on CT.

When looking at CT heads, you're mainly looking for bleeds in the brain, but you may also come across space occupying lesions and skull fractures.

Remember that subdural haemorrhages are convex shaped whereas epidural haemorrhages are crescent shaped.

CT head images are made up on many slices and it can be difficult to interpret a single slice, but as you gain confidence from looking at CT heads, it will become easier.


What's wrong with the quality of this film?

What's wrong with the quality of this film?

What's wrong with the quality of this film?

  • Penetration
  • Inclusion
  • Annotation

Cough and Shortness of Breath

A 10 year old child presents with cough and shortness of breath.

What is the abnormality seen?

What is the diagnosis?

  • Left pleural effusion
  • Left lower zone pneumonia
  • Pneumothorax
  • Heart failure

How will you treat?

  • Chest drain in mid-axillary line
  • Aspiration in midclavicular line
  • Antibiotics
  • Pleural tap
  • Oxygen only

NG tube

A 6 year old has had an NG tube put in for feeding. The ward nurse is asking you to confirm the correct placement.

Is the NG in the correct place?

  • Yes
  • No

What are the features you need to confirm correct NG placement?

  • Passes in midline
  • Bisects the carina
  • Passes below level of diaphragm
  • Tip curving towards cardia of stomach
  • Tip found in duodenum
  • All of the above

A well neonate

A neonate has a chest xray done. You cannot find any of the requesting information but the child looks well.

What does the xray show?

What does xray show?

  • Right Pneumonia
  • Right lung collapse
  • Broken rib
  • Thymus gland

Baby with dusky episodes

This baby's parents are concerned that she is having dusky episodes when she cries.

What is the diagnosis?

Cyanotic Heart Defect


Tetralogy of Fallot

Transposition of the Great Arteries

Eisenmenger Syndrome

  • this is progression of an acyanotic heart defect's left-to-right shunt (ASD, VSD, PDA) to cyanotic right-to-left shunt due to pulmonary hypertension

Acyanotic Heart Defect

(LEFT TO RIGHT Shunt/Obstructive)

Atrial Septal Defect

  • Patent Foramen Ovale

Ventricular Septal Defect


Coarctation of the aorta

Patent Ductus Arteriosus

Acyanotic heart defects are usually picked up as a murmur in a well baby check. Cyanotic heart defects are more symptomatic and brought to the attention of healthcare staff by concerned parents. 

They are referred for echo and to paediatric cardiologists. The echo will usally be able to characterise the type of heart defect.

  • Tetralogy of Fallot
  • Atrial Septal Defect
  • Ventricular Septal Defect
  • Patent Ductus Arteriosus

Distressed preterm neonate

This neonate is in NICU after being born pre-term.

She is unsettled with bowel distension, vomiting and diarrhoea.

What is the most likely diagnosis?

  • Constipation
  • Necrotising Enterocolitis
  • Hirschprung
  • Splenomegaly
  • Duodenal Atresia

Child with Green Vomit

A child presents with greeny-yellow vomit and is drawing his legs up to his chest.

What is the most likely diagnosis?

  • Volvulus
  • Constipation
  • Gastroenteritis
  • Necrotising Enterocolitis
  • Testicular torsion

Newborn with non-stop vomiting

This newborn has had vomiting since he was born 24 hours ago. He has not been able to keep down any food at all. He has also not passed any meconium

What is the diagnosis?

  • Duodenal atresia
  • Inguinal Hernia
  • Intussusception
  • Cystic Fibrosis

Baby with excessive sleepiness

This child is brought in by parents worried that he is "not like himself"

He is usually an alert baby. He was crying this morning when they left him with the babysitter but after getting back from work, they note he is unusually quiet and sleepy.

What is the diagnosis?

  • Subdural haemorrhage
  • Epidural haemorrhage
  • Intraventricular haemorrhage

What are possible causes of this diagnosis?

  • Shaken baby
  • Preterm baby
  • Head injury
  • Excessive crying
  • Overweight baby
  • All of the above

Painful ankle

This child was playing sports when they hurt their ankle.

What's the diagnosis?

  • Fractured femur
  • Epiphyseal fracture of tibia
  • Fracture of talus

Overweight child with limp

This child was brought in by parents who have noted he has started limping but they can't recall any history of trauma.

 On examination, you note his BMI is on the larger side. One of his legs seems externally rotated but he looks otherwise well.

What's the diagnosis?

  • Slipped Capital/Upper Femoral Epiphyses
  • Fracture neck of femur
  • Fracture of midshaft of femur
  • Septic arthritis
  • No abnormality seen

Child with unexplained bruising

A child with unexplained bruising is found to have this abnormality on xray

What type of fracture?

  • Comminuited
  • Spiral fracture
  • Bucket handle fracture
  • Simple
  • Transverse

What would be your management plan?

  • Involve senior regarding child protection/safeguarding
  • Skeletal survey
  • Call the police
  • All of the above