CT Whole-Body Trauma — Single Pass
Unenhanced head and cervical spine, then a contrast-enhanced acquisition from the thoracic inlet to the lesser trochanters. Thoracolumbar spine and pelvic reformats are generated from the torso dataset.
Timings, volumes and delays here are representative values drawn from published guidance. Scanner generation, injector, cardiac output and local preference all move them. Confirm against your department's own protocol before you rely on a number.
When to use it
- Significant blunt polytrauma in a patient stable enough to be scanned, meeting local major trauma imaging criteria.
- High-energy mechanism with an unreliable clinical examination, including the intubated or obtunded patient.
- Penetrating truncal trauma in a stable patient where the track needs defining.
Technique
- The head and cervical spine are acquired unenhanced first; giving contrast before the head acquisition compromises the haemorrhage assessment.
- The split-bolus single-pass approach halves the torso exposure relative to separate arterial and portal venous passes and has been adopted as standard practice for stable blunt trauma in several major trauma centres.
- A delayed acquisition through the abdomen and pelvis is added selectively for suspected urinary tract injury or to characterise active bleeding.
- Spine imaging comes from reformats of the same acquisition — rescanning the thoracolumbar spine separately is duplicated dose.
Where it goes wrong
- Scanning a haemodynamically unstable patient is a clinical governance failure rather than a protocol one; the decision to transfer belongs to the trauma team.
- Arms down through the torso pass creates severe streak across the upper abdomen; where the injury pattern allows, arms should be raised.
- Split-bolus enhancement does not look like a conventional portal venous study, and departments that switch protocols without briefing readers see mis-called organ enhancement.
- Rescanning the spine or pelvis rather than reformatting duplicates exposure in an already high-dose study.
- Assuming the pan-scan covers the extremities: dedicated limb imaging is a separate request.
Clinical questions that reach this study
Contrast
A split-bolus injection is widely used: a first slower portion to produce solid-organ parenchymal enhancement, followed after a short interval by a second faster portion for angiographic enhancement, with the whole torso then acquired in one pass. Published examples use around 65 mL at 2 mL/s followed 10 s later by around 85 mL at 3.5 mL/s.
- No oral contrast.
Acquisition
- Breathing
- Breath-hold where achievable; otherwise quiet respiration, accepting the artefact.
- Reconstruction
- Thin axial reconstructions of the whole torso with soft-tissue and bone kernels, plus dedicated spine, pelvis and, where indicated, extremity reformats from the same data.
- Preparation
- Haemodynamic stability sufficient to leave resuscitation is a clinical decision that precedes the request. Lines, monitoring and airway secured before transfer; arms positioned above the head for the torso pass where injuries permit. No oral contrast.
Phases
Each phase is authored once and shared across every protocol that uses it, so the physiology below is the same wherever you meet it.
- CT angiography, bolus-trackedNo fixed delay. A monitoring ROI is placed in the target vessel (commonly the aorta) and acquisition triggers at a set attenuation rise — a ~100 HU threshold is widely used — followed by a short diagnostic delay of a few seconds for table movement and breath-hold instruction. Confirm locally.
This is not a separate physiological phase so much as a technique for hitting one reliably. The transferable principle is that a fixed delay assumes an average circulation, and the patients who most need vascular imaging — the shocked, the failing, the arrhythmic, the aneurysmal — are precisely those whose circulation time is furthest from average. Tracking the bolus in the target vessel replaces that assumption with a measurement, so peak arterial opacification is achieved in the individual patient. The trade-off is that the technique commits the scan to whatever the monitoring ROI sees: a badly placed ROI, a mistimed breath-hold or a threshold reached by a contralateral vein produces a systematically mistimed study rather than a slightly degraded one.
- Portal venous phaseTypically ~60–90 s after the start of injection. Confirm locally.
The portal vein and hepatic veins are opacified and the liver is at maximum parenchymal enhancement; bowel wall, mesentery, spleen and peritoneum are all well enhanced. The transferable principle is that HYPOVASCULAR lesions are most conspicuous when the BACKGROUND peaks, so this is the single most productive general-purpose abdominal phase and the correct default when the question is "what is wrong in this abdomen?". Its corollary is the classic error: a hypervascular lesion that was obvious 30 s earlier can become isodense and invisible here, so a normal portal venous study never excludes hypervascular disease.
Safety checks this protocol carries
Derived from the contrast agent and phases above, not authored here — which is why they cannot drift apart from what the protocol actually does.
- Prior contrast reaction and elective premedication· nurse pre scan
- Intravenous access adequate for the planned injection· radiographer at scan
- Metformin and iodinated contrast· radiographer at scan
- Child-sized technique and contrast dose· radiographer at scan
- Pregnancy status before an ionising exposure· radiographer at scan
- Kidney function and intravenous iodinated contrast· radiographer at scan