CSH057 Image Interpretation (Theory)

What is the role of MRPBA?

Developing codes, standards and guidelines for MRPs under regulatory law

What is the role of ASMIRT?

A professional (voluntary) association that set standards of competency in practice, encourage continuing professional development and leading in research

Which two governing bodies outline the expectation of radiographers in terms of image interpretation?

MRPBA and ASMIRT

What are the three benefits of radiographer image interpretation?

• Improved service delivery

• Improved communication

• Improved patient management

What is a Salter-Harris 1 fracture?

Malalignment of the physis

What is a Salter-Harris 2 fracture?

Involves physis and metaphysis

What is a Salter-Harris 3 fracture?

Involves physis and epiphysis

What is a Salter-Harris 4 fracture?

Involves physis, metaphysis and epiphysis

What is a Salter-Harris 5 fracture?

Metaphysis and epiphysis pushed together

Which is the most common type of Salter-Harris fracture?

2

Which Salter-Harris fractures are intra-articular?

3, 4

List some common types of incomplete paediatric fractures.

• Plastic deformity

• Greenstick

• Lead pipe

• Buckle/Torus

What is a plastic deformity fracture?

Microfractures causing a bend

Why might a lateral chest view performed?

• Assessment of fissures for collapse

• Localising consolidation (NOT apices)

• Localising large nodule/mass (NOT apices)

• Checking hila

• Visualisation of prosthetic valves

• Assessment of hemidiaphragms

• Assessment of vertebral bodies

• Assessment of hernias

Why might a lateral decubitus chest view be performed?

Pleural effusion, pneumothorax

What is a silhouette sign? Name one example.

When two structures of the same density are adjacent, the interface between them cannot be delineated (e.g. pneumonia in the right middle lobe creating a silhouette sign between the right heart border and right hilum)

Which lobe is involved when there is an ill-defined/absent right hemi-diaphragm and cardiophrenic angle?

RLL

Which lobe is involved when there is an ill-defined/absent right heart border and right hilum?

RML

Which lobe is involved when there is an ill-defined/absent right uppermediastinum?

RUL

Which lobe is involved when there is an ill-defined/absent left heart borer and aortic knuckle?

LUL

Which lobe is involved when there is an ill-defined/absent left heart border and medial aspect of left hemi-diaphragm?

LLL

Where do pericardial fat pads sit?

Supero-medial aspects of hemidiaphragms which overlay the heart borders

What might pectus excavatum resemble?

RML or RLL pathology

What is an air bronchogram sign? What is its significance?

When the more peripheral intrapulmonary bronchi can be seen surrounded by air, due to alveolar infiltrate/consolidation. Helpful in distinguishing consolidation from collapse or effusion

Which hilum sits higher: L or R?

L

Which rib levels constitute the ‘upper zone’ of the chest?

2nd rib and above

Which rib levels constitute the ‘middle zone’ of the chest?

2nd to 4th rib

Which rib levels constitute the ‘lower zone’ of the chest?

4th rib down

What are the three types of pneumothoracies?

Open, closed, tension

What is an open pneumothorax? Give one example.

When external air has been forced into the pleural space via a penetrating injury (e.g. gunshot through rib)

What is a closed pneumothorax? Give one example.

When air from the lung enters the pleural space from blunt trauma (e.g. rib fracture)

What is a tension pneumothorax?

When there is continuous entry of air into the pleural space, pushing the mediastinal contents to one side

What is a deep sulcus sign? On what radiograph might this been seen?

When air collects anteriorly and basally within the non-dependent portions of the pleural space, seen on a supine CXR.

What are some radiographic features of a tension pneumothorax?

• Tracheal shift (away from collapsed lung)

• Mediastinal shift

• Flattened diaphragm

Which ribs require high force to fracture?

1-3

Which ribs are the most commonly fractured?

4-10

List some risks posed by rib fractures.

• Pleural effusions

• Lung contusions

• Closed pneumothoracies

• Vessel ruptures

What is a flail segment? What makes a flail segment particularly dangerous?

When a segment of the thoracic cage is separated from the rest of the chest wall, results in reduced capacity for lung expansion making it harder for the body to repair itself

What causes a pneumomediastinum?

Rupture of the trachea, pharanx or oesophagus

What is a continuous diaphragm sign? What does it suggest?

When the hemidiaphragms seemingly connect due to free gas within the mediastinum, pericardium, or peritoneal cavity, suggesting pneumomediastinum

What might a deep sulcus sign suggest on a supine CXR?

Pneumothorax

What causes subcutaneous epmhysema?

Gas rising internally or introduced externally

What are some radiographic features of subcutaneous emphysema?

• Linear streaky pattern

• Focal or diffuse radiolucent patches embedded within soft tissue

What is a haemothorax? What might cause it?

A collection of blood in the pleural space, caused by a blunt or penetrating trauma the ruptures the serous membrane

What is a meniscus sign? What does it indicate on a erect CXR?

A crescent-shaped collection of air surrounded by consolidated lung tissue, suggesting a haemothorax

What is a pulmonary contusion?

An injury to lung parenchyma, causing oedema and blood collection in the alveolar space and loss of normal lung structure and function

What does a pulmonary contusion look like radiographically?

Patchy air space opacification (‘fluffy’), either focal or diffuse

What is the radiographic difference between consolidation and pleural effusions?

• Consolidations have air bronchogram signs whereas pleural effusions don’t

• Consolidations are fluffy in appearance whereas pleural effusions are more solid (on erect views)

What is an ETT? Where should it sit?

Endotracheal tube, should sit 4cm above the carina

What is an ICC? Where should it sit?

Intercostal catheter, sits within the chest cavity

If an ICC is sitting antero-superiorly and pointing up, is it likely to be draining a pneumothorax or a pleural effusion?

Pneumothorax

If an ICC is sitting postero-inferiorly and pointing down, is it likely to be draining a pneumothorax or a pleural effusion?

Pleural effusioin

What is a CVL? Where should it sit?

Central venous line, should sit within the SVC/RA junction

What is a NGT? Where should it sit?

Nasogastric tube, should sit within the stomach

What is a pleural effusion? List some causes of pleural effusions.

An abnormal amount of fluid around the lung, can be caused by congestive heart failure, pulmonary embolism, infection, neoplasm or recent surgery

What is consolidation?

Airspace opacification (by fluid or solid material) without loss of volume

List some causes of consolidation?

• Transudate

• Pus

• Blood

• Cells

• Protein

• Fat

• Gastric contents

What are some radiographic features of lobar pneumonia/consolidation?

• Increased opacity of the lung

• Air bronchogram

• Involves one or more lobes

What are some radiographic features of bronchopneumonia?

• Patchy areas of consolidatioin within the lung

• Usually bilateral and lower lobes

What are some radiographic features of interstitial consolidation?

• Faint increased lung opacity

• Linear opacities

• Diffuse bilateral

Which type of pneumonia may demonstrate air bronchograms on a radiograph?

Lobar pneumonia

What is atelectasis? What are some radiographic features of atelectasis?

Partial or complee lung collapse, demonstrated by lung opacity and volume loss

List some causes of atelectasis.

• Aspirated FB

• Mucous plugging

• Bronchogenic carcinoma

• Compression by adjacent mass

What are the radiographic differences between consolidation and collapse?

• Consolidation can have air bronchograms, collapse does not

• Consolidation does not cause fissure movement, collapse does

• Consolidation does not affect the size of the lobe, collapse does

If there is a silhouette sign of the medial and posterior right hemidiaphragm and the right hilum is depressed, which lung lobe may have collapsed?

RLL

If there is a silhouette sign with the right heart border but the hilar position is maintained, which lung lobe may have collapsed?

RML

If the right hilum is elevated, which lung lobe may have collapsed?

RUL

If there is a silhouette sign of the medial and posterior left hemidiaphragm and the left hilum is depressed, which lung lobe may have collapsed?

LLL

If there is a silhouette sign with the left heart border and the left hilum is elevated, which lung lobe may have collapsed?

LUL

What may a primary spontaneous pneumothorax be caused by?

A ruptureof the alveoli, bleb or bulla

What may a secondary spontaneous pneumothorax be caused by?

A complication of an underlying lung disease, like asthma, CF, whooping cough

What is congestive cardiac failure? List some causes of congestive cardiac failure.

When the heart is unable to pump efficiently

• Myocardial infarction

• Chronic health problems

• Heart disease

• Diabetes

• Hypertension

What is cardiomegaly? What might it indicate?

When the cardio-thoracic ratio on a PA CXR is greater than 50%, suggesting congestive cardiac failure

List some radiographic features of congestive cardiac failure.

• Cardiomegaly

• Pleural effusion

• Pulmonary oedema

• Kerley B lines

• Cephalisation

What is a batwing appearance? What does it indicate?

Increased density next to the hila bilaterally, indicating pulmonary oedema

What are Kerley B lines? What do they indicate?

Horizontal lines in the lung periphery that extend to the pleural surface, usually at the lung bases, they indicate cardiac failure

What is cephalisation? What does it indicate?

Pulmonary vessels in the upper lobes increase in size and become more obvious, indicating cardiac failure

List some causes of pericardial effusion.

• Infection

• Inflammation

• Trauma

List some radiographic features of pericardial effusion.

• Globular cardiac outline

• Well-defined cardiac contour

• Rapid alteration in heart size

What might a globular cardiac outline and well-defined cardiac contour indicate?

Pericardial effusion

Which structures should be carefully assessed under the ‘airways and mediastinum’ search in a CXR?

• Lung fields

• Hilar

• Diaphragm

• Pleua

• Mediastinum and heart

What are the review areas in a CXR STAR?

• Apices

• Hila

• Retrocardiac space

• Sub-diaphragmatic

Why are children more likely to endure fractures involving their growth plates than their midshaft etc.?

Paediatric ligaments and tendons are stronger than immature bones, so fractures are more common than ligamentous damage. Before puberty the growth plates are the weakest part of the bone, hence the propensity for growth plate fractures (Salter-Harris).

What are the review areas for the phalanges (fingers)?

Soft tissue attachments (e.g. radial and ulnar collateral ligaments, extensor tendons, flexor tendons, volar plate)

What MOI may result in a volar avulsion fracture? What are some radiographic findings of volar avulsion fractures?

Forced extension, resulting in a bony fragment at the base of the phalanx at the insertion site of the volar plate or flexor tendon

What MOI may result in a dorsal avulsion fracture? What are some radiographic findings of dorsal avulsion fractures?

Forced flexion, resulting in a bony fragment at the base of the phalanx at the insertion site of the extensor tendon

What is a mallet deformity?

Injury to the distal interphalangeal joint due to forced extension, resulting in a tear or avulsion fracture of the extensor tendon

What MOI may result in a collateral avulsion fracture? What are some radiographic findings of collateral avulsion fractures?

Abduction or adduction, resulting in a bony fragment at the base of the phalanx (either on the radial or ulnar side)

What is a skier’s thumb injury?

A rupture or avulsion of the ulnar collateral ligament of the first metacarpophalangeal joint

What is the review area for the hand?

Base of metacarpals

Where does the deep ulnar ligament attach?

Ulnar aspect of the base of the first metacarpal

Where does the abductor pollicis longus tendon attach?

Radial aspect of the base of the first metacarpal

What two important structures attach to the base of the first metacarpal?

Deep ulnar ligament (ulnar aspect) and abductor pollicis longus tendon (radial aspect)

What is the MOI for a punch injury? What are some associated radiographic findings?

Axial loading with possible rotation, resulting in

• Fracture of the head, neck or base of the fifth metacarpal

• Potential volar angulation

• Potential carpometacarpal involvement

• Hamate fracture

What is a Bennett’s injury? What are some associated radiographic findings?

Intra-articular fracture dislocation/subluxation of the first carpometacarpal joint with retraction of the abductor pollicis longus tendon causing dorsal and radial displacement

What is soft tissue structure is involved in a Bennett’s injury?

Abductor pollicis longus tendon

What is a Rolando injury? What are some associated radiographic findings?

Intra-articular comminuted fracture dislocation of the base of the first metacarpal, either presenting as a T or Y configuration

Which is more common: Bennett’s or Rolando injuries?

Bennett’s

What is the most common injury from a FOOSH for a child younger than 5 years old?

Clavicle fracture

What is the most common injury from a FOOSH for children aged 3-9 years old?

Supracondylar fracture of the humerus