Imaging in Trauma

Question 1

What type of medical professional should images be discussed with?

Answer 1

IMAGING IN TRAUMA

• Surgeons
  
  • trauma
  • ortho
  • neurosurgeon
• Experienced emergency radiographer (technician)

Question 2

What is the best imaging modality for accurately detecting bleeding in trauma?

Answer 2

CT.

Question 3

What are the indications for whole body CT and what does this entail? When is it NOT appropriate?

Answer 3

TRAUMA

WHOLE BODY CT

• = head to pubic symphysis
• Indication
  
  • CRITICALLY injured
  • MULTISYSTEM trauma
• WHEN: w/i 30 mins of pt’s arrival
• ROUTINE use of head to thigh polytrauma CT NOT appropriate
• although combination injury to head + abdomen + extremities is common, data shows areas b’w injuries are not commonly injured e.g. pelvis/ C-spine injury is RARE => do NOT routinely image B/W 2 injured areas
• keep the radiation dose ALARA (as low as reasonably possible)

Question 4

What type, mechanism and area of injury is most common in trauma?

Answer 4

TRAUMA

MOST COMMON

• Blunt > Penetrating
• Fall > RTA
• HI > extremities > abdomen

Question 5

Who must accompany the injured child to the radiology department and why?

Answer 5

A core component of the trauma team - in case there is deterioration.

Question 6

What ROUTINE imaging is recommended for a primary survey in trauma?

Answer 6

PRIMARY SURVEY - TRAUMA

ROUTINE IMAGING

1. CXR
2. C-spine XR
   
   • ONLY if unable to clear clinically
   • OR up front indication for CT

NB do NOT routinely perform pelvic XR

Question 7

What is the risk of performing a CT C-spine?

Answer 7

200 x radiation dose of 3-view XR

Delivered to developing thyroid gland

DO NOT ROUTINELY REQUEST

Question 8

Is there a role for FAST (Focused Abdominal Sonography for Trauma) in paediatric trauma?

Answer 8

FAST

= Focused Abdominal Sonography for Trauma

• NO role in paeds trauma
• Only 50% sensitive for free fluid in the abdomen
• If suspecting bleeding in the abdomen do CT with contrast

Vs. Formal abdo USS may be helpful

Question 9

What is the first line investigation for suspected bleeding in the abdomen?

Answer 9

CT with contrast.

Question 10

Are lateral C-spine XR’s useful?

Answer 10

BONY injury: Can NOT R/O using this alone.

CORD injury: Normal film does NOT R/O = SCIWORA - need MRI/ clinical assessment whilst awake.

Snapshot of the position of the bones at the time of the film, does not indicate degree of flexion/ extension forces applied to the spine at the time of injury.

Question 11

When is a pelvic XR indicated and when is it not?

Answer 11

TRAUMA

PELVIC XR

• ROUTINE use NOT recommended
  
  • High dose of radiation
  • # s causing sig. pelvic ring disruption are
    • rare (excluding isolate pubic ramus #)
    • usually clinically evident (manage w/ pelvic brace and fluids/ blood)
  • Pubic rami fractures are relatively common but do not cause much bleeding or threat to LOL (life, organ, limb)
• Indication: strong suspicion of pelvic ring injury

Question 12

What type of imaging is indicated if C-spine injury is suspected and WHEN should this be perfomed?

Answer 12

C-SPINE INJURY

IMAGING

• CT C-spine
  
  • High index of suspicion/ high risk mechanism of injury (bony injury)
  • plain films unclear/ abnormal
• 3 view C-spine XR
  
  1. AP
  2. Lateral
  3. Odontoid PEG view (if child is able to open mouth)
  • Lower index of suspicion (bony injury)
• MRI
  
  • Strong suspicion of C-spine CORD injury
• Perform imaging ONLY after life-threatening injuries have been identified & treated

Question 13

What should take place before any cervical imaging is performed?

Answer 13

C-spine immobilisation.

An inadequately immobilised C-spine # can cause progressive spinal cord damage.

Blocks rather than sandbags ideally.

Sandbags can obscure bony landmarks.

Question 14

What kind of signs and symptoms raise the suspicion of C-spine CORD injury?

What should be done in these children?

Answer 14

C-SPINE CORD INJURY

• Positioning: oddly positioned or twisted head/ neck/ back
• Power: weakness/ paralysis, difficulty breathing
• Reflexes: loss of bladder/ bowel control
• Coordination: incoordination
• Sensation: altered sensation/ paraesthesiae/ numbness, extreme pain/ pressure in the head/ neck/ back
• Mx
  
  • continue neck protection measures
  • URGENT MRI

Question 15

What landmarks should be imaged in a CT C-spine in different age groups?

Answer 15

CT C-SPINE

LANDMARKS

• < 10 yo
  
  • upper C-spine incl. craniocervical junction (most common site of injury in < 10 yo)
  • FROM occipital condyles + foramen magnum
  • TO C3
  • avoids radiosensitive thyroid
• > 10 yo
  
  • as for adults
  • FROM occipital condyles
  • TO C7/ T1 junction

Question 16

What is the most common site of C-spine injury in children under the age of 10?

Answer 16

Craniocervical junction

= the interface b/w SKULL + C-Spine

Includes:

• occipital bone surrounding foramen magnum
• 1st and 2nd vertebra (C1 = atlas, C2 = axis)

Question 17

How do patterns of C-spine injury differ in children and adults & why?

Answer 17

PATTERNS OF C-SPINE INJURY

CHILDREN Vs. ADULTS

• large mass of head (relative)
• moving on a flexible neck
• poorly supportive muscles
  
  • => injury in the higher cervical vertebrae
• injuries through discs and ligaments at
  
  • carniovertebral junction (C1, 2, 3)
  • C7 / T1

Question 18

Describe the 3 main patterns of C-spine injury that occur in children.

Answer 18

PATTERNS OF SPINAL INJURY

CHILDREN

1. FRACTURE +/- SUBLUXATION/ DISLOCATION
2. SUBLUXATION/ DISLOCATON - NO #
3. SCIWORA (Spinal Cord Injury WithOut Radiographic Abnormality)

Question 19

What is SCIWORA and what is the only way to R/O spinal cord injury?

Answer 19

SCIWORA

= Spinal Cord Injury WithOut Radipgraphic Abnormality

• significant cord injury
• BUT radiographic films completely normal
• R/O spinal cord injury
  
  • MRI
  • clinical assessment in AWAKE child

Question 20

What is the most common site of a missed spinal injury?

Answer 20

Where a flexible part of the spine meets a fixed part

e.g. in the neck

cervicocranial junction &

cervicothoracic junction (C7 - T1)

Question 21

How do you check the adequacy of cervical spine imaging and what should be done if it is not adequate?

Answer 21

CERVICAL SPINE IMAGING

ADEQUACY

• whole spine visible
  
  • FROM lower clivus
  • TO upper body of T1
  • incl. C7-T1 junction
• If C7-T1 junction not visible
  
  • conscious child - ‘relax shoulders’
  • assistant - stabilise spinal board (if used)
  • hold arms above elbow joint
  • gentle traction - pull arms down

Question 22

What is chest USS useful for?

Answer 22

USS CHEST

Detection of:

PTX

Haemothorax

Question 23

How do you check the adequacy of a CXR?

Answer 23

CXR

Adequacy = RIP

1. ​Rotation: medial ends of both clavicles equally spaced about the spinous processes of the upper thoracic vertebrae, trachea equally spaced b/w the clavicles ​
2. Inspiration: at least 5 anterior rib ends above the diaphragm on the R side
3. Penetration: able to just visualise the disc spaces of the lower thoracic vertebrae through the heart shadow

Question 24

When is CT chest NOT required?

Answer 24

Normal CXR.

Question 25

Described a structured approach to reporting a CXR and what should be looked for.

Answer 25

CXR REPORTING Position + ABCDEFGHI * Position: AP/ PA/ Lateral? * Airway + Apparatus + Alignment * Airway: * Trachea central/ deviated (mass effect e.g. PTX, pleural effusion or pulled by lung collapse) * * Apparatus: * ETT - 1st thing to r/v in intubated pt's (below clavicles & at least 1cm above carina) * NGT/ OGT (should bisect the carina i.e. below the carina =\> not in oesophagus) * CVP * chest drains * Wires/ clips from previous surgery * Alignment (spine) - 4 lines - the continuity of the lines should be maintained regardless of the degree of neck flexion/ extension - look for steps and angulation 1. anterior vertebral line 2. posterior vertebral line (anterior wall of the spinal canal) 3. facet line 4. spino-laminar line (posterior line of the spinal canal) * Bones & Soft tissues * Bones * posterior, lateral and anterior aspects of each rib * vertebrae - flattening = thoracic injury * clavicles * scapulae * proximal humerus * Look for * symmetry * fractures * of ribs only w/ considerable force * even greater if multiple or first rib # (look for other injuries inside & outside chest) * 1st 3 ribs --\> look for great vessel injury + major spinal trauma * osteoporosis * lesions * widening * disc spaces (thoracic injury) * gaps b/w spinous processes of pedicles (increased vertical or horizontal distance = unstable fracture) * Soft tissues * FB * SC air * haematoma * Cardiac * 1/3 to the R of the midline + 2/3 to L * mediastinal shift * pushing (mass effect) = Tension PTX, pleural effusion * pulling = collapse * cannot assess heart size on trauma films as these are all AP * Cardiophrenic angle blunting = consolidation * Globular shape = pericardial effusion (use cardiac ECHO if in doubt) * Diaphragm OR Disc spaces (spine) * L diaphragm should be visible behind the heart (if not - LLL collapse) * unilaterally raised (Hump) * normal slight on R (liver) * PTX * FB / collapse * diaphragmatic rupture * effusion * nerve palsy * B/L flattened - chronic asthma/ emphysema * Subdiaphragmatic free air * Disc spaces (spine) * Effusions * blunted costophrenic angles = pleural effusion/ haemothorax * lateral film ? posterior effusion * Fields/ Fissures + FB * Fields * APICES * Consolidation * air bronchograms * masses * PTX -- classical signs (lack of vascular markings at lung peripheries) not seen in supine film as air rises anteriorly --\> look for abnormal sharpness of diaphragm/ cardiac border * Fissures: * thickening * fluid = upper lobe collapse * change in position (elevation) = " * Great vessels + Gastric bubble * Great vessels * aortic size + shape + aortic knob/ knuckle (loss of definition = aneurysm) * pulmonary vessel outlines * aortopulmonary window (loss of definition = lymphadenopathy e.g. malignancy) * Gastric bubble * present + not diplaced * Hila & mediastinum * Hila * lymphadenopathy * masses * L often higher than R * Mediastinum * widening e.g. aortic dissection, spinal trauma, major vessel injury (rare in small children) --\> USS/ CT/ angiogram * \< 18 months --\> thymus simulates superior mediastinal widening (above carina) -- may reach L/R chest wall or diaphragm * Impression

Question 26

What are the indications for abdominal CT with contrast in trauma?

Answer 26

ABDO CT + CONTRAST INDICATIONS * Abdo tenderness (conscious pt) * Hypovolaemia - persistent * Blood from rectum/ NGT * Handle bar injuries (significant) * Bruising/ injury of abdo wall/ lap belt area * Abdo distension

Question 27

What is the prime modality for excluding acute intracranial haemorrhage?

Answer 27

CT brain. NB intracranial bleeding in children often occurs WITHOUT skull # =\> do not do a skull film.

Question 28

How do you assess alignment in the cervical spine? What 4 lines should you be looking for?

Answer 28

C-SPINE XR ALIGNMENT * 4 lines 1. anterior vertebral line 2. posterior vertebral line (anterior wall of the spinal canal) 3. facet line 4. spino-laminar line (posterior line of the spinal canal) * the continuity of the lines should be maintained regardless of the degree of neck flexion/ extension * look for steps and angulation

Question 29

What is the most common mechanism of injury of the lumbar and thoracic spine? What is the most common radiographic finding?

Answer 29

Hyper-flexion Wedge or beak shaped vertebra from compression