The lumbar spine series is comprised of two standard projections along with a range of additional projections depending on clinical indications. The series is often utilized in the context of trauma, postoperative imaging and for chronic conditions such as ankylosing spondylosis.

Lumbar spine radiographs are one of the more commonly requested radiographic investigations of the spine, however, projectional radiography has limitations and further imaging such as MRI and CT should be considered for further evaluation if justified by presenting clinical presentation ^1,2.

Imaging of the lumbar spine for back pain in the acute or sub-acute setting, without any concern or indication of a serious condition will not improve clinical outcomes ⁴.

Indications

Lumbar spine radiographs are performed for a variety of indications including:

• fall from a height of greater than 3 meters

• ejection from a motor vehicle or motorcycle

• acute back pain

• neurological deficit

• postoperative imaging

• chronic conditions

• history of cancer and associated back pain

Projections

Standard projections

• PA/AP view

  • the entire lumbar spine should be visible, with a demonstration of T11/T12 superiorly and the sacrum inferiorly

  • often performed erect unless otherwise indicated

• lateral view

  • visualization of lumbar vertebral bodies, pedicles, and facet joints

  • ideal projection when examining for suspected fractures

  • can be performed erect to assess stable fracture (under a specialist's guidance)

Modified trauma projections

• horizontal beam lateral

  • visualization of lumbar vertebral bodies, pedicles, and facet joints

  • taken supine

  • used in the context of trauma

Additional projections

• oblique view: used to visualize the articular facets and pars interarticularis of the lumbar spine

• flexion-extension view: functional view used to assess for spinal instability