CT polytrauma (technique)
CT polytrauma/multitrauma, also called trauma CT, whole body CT (WBCT) or panscan, is an increasingly used investigation in patients with multiple injuries sustained after significant trauma.
Clinical assessment and mechanism of injury may underestimate injury severity by 30% . There is some evidence from meta-analyzes that trauma patients who undergo WBCT have better survival than patients who undergo selective imaging but this is yet to be definitely proven in randomized controlled trials . Patients who undergo immediate WBCT at presentation have a similar radiation dose at discharge to patients who undergo a selective imaging strategy . As well as traumatic injuries, trauma CT uncovers incidental findings which have varying levels of significance .
Indications
Indications will vary from institution-to-institution but indications by mechanism include:
- high speed motor vehicle collision
- non-trivial motorcycle collision
- death at the scene
- fall from height >2 meters
- other concerning mechanism of injury
- abnormal FAST, or trauma chest or pelvis x-ray
- abnormal vital signs
Technique
The actual procedure will vary depending on institutional protocol/guidelines, but a typical protocol will include non-contrast and contrast-enhanced CT of the head, neck, chest, and abdomen/pelvis:
- non-contrast CT brain +/- face
- non-contrast CT cervical spine
- CT thorax and upper abdomen in angiographic or delayed phase
- CT abdomen/pelvis in portal venous phase
- multiplanar reconstructions of the thoracic and lumbar spine
Additionally, depending on the injuries present and especially if the images are reviewed with the patient on the CT table, the following phases may be useful:
- CT angiogram neck/circle of Willis: penetrating neck injuries or risk factors for blunt cerebrovascular injuries
- delayed phase of the abdomen/pelvis: useful to assess for contrast pooling/contrast extravasation indicative of active bleeding
- renal excretory phase of the abdomen/pelvis: useful in patients with traumatic renal injuries (to assess for urinoma and upgrade AAST grading)
- CT cystogram to assess for bladder injury
There are numerous variations including:
- additional non-contrast CT of the upper abdomen
- CT angiogram of the abdomen/pelvis and lower limbs in the setting of suspected major hemorrhage and/or pelvic/lower limb fractures
- triphasic injection single pass CT of the chest, abdomen and pelvis
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