Trauma radiographs requested before CT in a haemodynamically borderline patient
A 34-year-old man is brought to the emergency department of a Kuwait MOH trauma centre after a high-speed road traffic collision. He is borderline haemodynamically (BP 88/54 mmHg, pulse 128), with a GCS of 14 (E3 V4 M6), neck pain and midline tenderness at C6, and an unstable pelvis on log-roll. He is on a long spine board with a rigid cervical collar, a pelvic binder has been applied, and he has two large-bore intravenous lines and a urinary catheter in place. The trauma team leader asks for a cross-table lateral cervical spine and an AP pelvis 'now, before CT', because the CT scanner is occupied for a further 20 minutes with another patient. The radiographer is asked to bring a mobile unit to the resuscitation bay. The patient has very muscular shoulders and cannot be sat up or turned.
1. Evaluate the request: which projections would you accept, which would you decline, and what is your justification reasoning?
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Accept: AP pelvis. It is a single, low-dose projection taken without moving the patient, it can be done on the trolley with a detector slipped under the board, and it directly changes immediate management - it confirms or refutes a major pelvic fracture and informs whether the binder must stay, whether interventional radiology or theatre is needed, and whether blood products are escalated while CT is occupied. Benefit clearly outweighs the small dose.
Accept with conditions: cross-table lateral cervical spine. It is a screening image only. It gives the team a first look at gross malalignment during a 20-minute delay and is done without removing the collar or moving the patient's head. Conditions: it must not delay transfer to CT, it must not involve lifting or turning the patient, and the requesting clinician must understand that a normal lateral film does not clear the cervical spine.
Decline: everything that requires manipulation or provides no acute benefit - open-mouth odontoid (requires mouth opening and beam angulation across an uncleared spine), swimmer's view (requires arm positioning and shoulder traction in a patient who cannot be moved), flexion-extension views (absolutely contraindicated), and oblique views. There is no role for these in the acute resuscitation phase; CT is the reference standard in a GCS 14 patient with midline tenderness.
Justification. Justification is a professional duty, not a clerical step. The reasoning to state aloud and document is: does this projection change what happens to the patient in the next 30 minutes, and can it be obtained without moving an unstable spine? If yes, do it well and quickly; if no, say so and escalate.
2. Describe how you would optimise the cross-table lateral cervical spine with the patient supine, and when you would stop and accept a non-diagnostic image.
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Technique reasoning.
- Detector vertical in a cassette holder or a dedicated cross-table device, centred at the level of C4, with a horizontal beam and a 150-180 cm source-to-image distance to reduce magnification of an already difficult projection.
- Lead-rubber or the apron on the trolley behind the detector to reduce backscatter, and collimation to the spine to protect the thyroid and reduce scatter - collimation is one of the few dose levers available here.
- Collar left in place. Removing it to improve image quality is a decision for the trauma team, not the radiographer, and is not made for a screening film.
- Gentle caudal traction on both shoulders by an assistant, applied only if the trauma team agrees and only while the patient reports no new pain, no paraesthesia, no weakness and no change in breathing. Any neurological symptom stops the manoeuvre immediately.
- Exposure at end-expiration, since relaxed shoulders sit lower; in a distressed patient this may not be achievable, which is itself a reason not to persist.
- Keep the head in the neutral position the collar holds it in; do not extend or rotate the neck to clear the shoulders.
When to stop. The film is adequate only if C1 down to the C7-T1 junction is visible. If after two or three well-reasoned attempts the shoulders still obscure the lower cervical spine, stop. Each further attempt adds dose to the thyroid and lens and delays definitive imaging. Document on the image and in the notes that the film is non-diagnostic below C6, tell the trauma team leader verbally, and press for CT - which is where this patient is going anyway.
3. For the AP pelvis, what positioning and shielding decisions would you make, and how would you handle the pelvic binder?
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Positioning. The patient stays supine on the trolley on the long board; no rolling and no log-roll for the film. Place the detector in the tray under the trolley or slide a grid cassette beneath the pelvis only if doing so does not require lifting the patient - if it does, ask the team to log-roll with manual in-line stabilisation of the spine, or use a detector already under the board. Centre the beam at the level of the symphysis pubis with the top of the field at the iliac crests, include the proximal femora and the whole pelvis, and collimate laterally to the soft tissue margins. No tube angulation on a trauma AP pelvis - angulation distorts the ring and the femoral neck.
Shielding decision. Do not apply gonadal shielding here. In a suspected unstable pelvic fracture the shield can obscure the pubic symphysis, the pubic rami and the sacroiliac region - exactly the structures being looked for - and a repeat film after removing it delivers more dose than the shield saves. The single AP projection is already a low-dose study. This is a defensible, documented deviation from routine shielding practice for a clinical reason.
The binder. Do not remove or loosen it. The binder is a haemostatic device; releasing it in a borderline patient can precipitate rebleeding. Image through it, collimate to the pelvis, and accept the modest loss of detail from the overlap. If the trauma team decides it must be released for clinical reasons, that is their decision and it is done with blood products running and staff ready to reapply.
Afterwards. Evaluate the image before leaving the bay: symmetry, coverage of both hips, exposure indicator, and any suspicion of movement. Report a suspected fracture verbally immediately rather than waiting for the formal report.