Spinal radiograph — AP and lateral
Region of interest with adequate visualisation of the cervicothoracic junction where relevant
When to use it
- Alignment, deformity, instrumentation position.
- Suspected vertebral collapse.
Technique
- AP and lateral projections of the named region, erect where the question is alignment or deformity and supine where the patient cannot stand — the projection changes the answer, since degenerative listhesis reduces on lying down and a scoliosis curve measured supine is not comparable with an erect Cobb angle.
- Cervical spine: AP and lateral with the shoulders depressed, and a swimmer's view added when C7/T1 is not seen — a lateral that stops above the cervicothoracic junction is an incomplete study, not a normal one. An open-mouth peg view is included where the odontoid is in question.
- Thoracic and lumbar spine: centred at about T7 and at L3 respectively, exposed on arrested expiration for the thoracic region and on arrested respiration for the lumbar, with the knees flexed on the lateral lumbar projection to reduce lordosis and open the disc spaces.
- A dedicated coned lateral of the lumbosacral junction is added where L5/S1 is the level of interest, because it is routinely obscured by the iliac crests on the standard lateral.
- Flexion and extension laterals are acquired only where dynamic instability is the specific question, and never in acute trauma or where cord compromise is suspected.
- Collimate tightly and use the highest practicable kVp with a grid: a lumbar spine series is one of the higher-dose plain film examinations, and an erect AP lumbar spine delivers a substantial gonadal and, in women, breast dose — which is part of why current guidance discourages it for uncomplicated back pain.
Where it goes wrong
- Cannot assess the cord, the disc or the epidural space. Any question of cord compression or cauda equina requires MRI, and a normal radiograph must never be used to exclude them.
Clinical questions that reach this study
Contrast
None
Acquisition
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.
- Child-sized technique and contrast dose· radiographer at scan
- Pregnancy status before an ionising exposure· radiographer at scan