Modalities of Imaging

Plain film X-rays

The X-ray department should have a general X-Ray table, upright X-Ray facilities and additional portable facilities for use in the trauma bay/resuscitation area. The presence/absence of a film processor is dependent upon proximity to the main Medical Imaging Department or the use of digital radiography.
The trauma series of x-rays is commenced as soon as is practicable in the reception of the patient to the ED. Direct digital radiography (DR) should be used in the emergency department and the images viewed initially on a non-diagnostic built-in screen. The images are subsequently uploaded to a picture archiving and communication system (PACS) system for reporting.
Plain films can be used to evaluate limb injuries prior to surgery and are also used for standard indications in the emergency department.

  • Excellent evaluation of osseous structures.
  • Fast.
  • Portable.
  • Inexpensive.
  • Highest spatial resolution.
  • Limited soft tissue contrast
  • Ionising radiation

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Ultrasound is utilised in the form of Focused Assessment with Sonography in Trauma (FAST) at all trauma calls and is now the diagnostic imaging of choice in the unstable trauma patient with intra-abdominal haemorrhage who requires urgent surgery. The scan is performed in parallel with the primary survey of the patient as part of the initial resuscitation. The FAST scan is extended to include the pericardium and the pleural spaces, in addition to the abdomen and pelvis.3 The examination can be completed in around 2-5 minutes, is non-invasive and repeatable.
If the patient is found to have free fluid in a body cavity, and is too unstable clinically to undergo MDCT, urgent surgery should be undertaken prior to imaging with MDCT.
When patients arrive who are undergoing cardio-pulmonary resuscitation (CPR), ultrasound of the heart is performed to establish if there is spontaneous cardiac motion and to exclude cardiac tamponade. Ultrasound is occasionally performed intra-operatively to identify sources of haemorrhage distant from the current operative site (e.g. chest and upper abdomen during a pelvic fixation procedure).
Ultrasound is also used for image-guided chest drain insertion, vascular access and pericardiocentesis when immediate surgery is not an available option.

  • Portable.
  • No ionising radiation.
  • Less expensive than CT or MRI.
  • Low sensitivity and specificity for detecting visceral injuries and haemoperitoneum.
  • Operator dependant.
  • Does not adequately evaluate retroperitoneum, gas containing structures and mediastinum.

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CT scanning

MDCT is generally undertaken only on stable patients. If patients cannot be stabilised in the emergency department they are taken immediately to the operating theatre and receive damage control surgery. Once stabilised they can then receive MDCT.

  • Excellent soft tissue contrast resolution.
  • Fast / readily available.
  • High sensitivity and specificity.
  • Excellent evaluation of all tissues.
  • Expensive.
  • Requires the patient to be hemodynamically stable.
  • Time consuming.
  • Exposure to ionising radiation.


Rarely used in the trauma setting.

  • Uses non-ionising radiation.
  • No known deleterious effects.
  • Excellent soft tissue contrast.
  • Modality of choice for spinal cord injury.
  • Longer image acquisition time.
  • Limited availability.
  • Expensive.