L-spine X-ray positioning

How to position for each of the 6 L-spine X-ray views: where the patient goes, where to centre, which receptor and distance to use, and what a good image looks like.

By the ScanFlo Editorial Team · Updated 6 October 2026

X-ray positioning/L-spine

The routine L-spine views are Lumbar spine AP, Lumbar spine lateral and Lumbosacral junction lateral. Lumbar spine lateral (after injury), Lumbar spine lateral in extension and Lumbar spine lateral in flexion come in when you need to answer a particular question, or when the patient can't manage a routine view. Each guide walks you through the set-up step by step, with a short video, exposure settings for different patient sizes and what a good image should show.

A radiographer is still checking these guides.

Routine views

Lumbar spine AP →Supine · 100 cm · centring point: L3, at the lower costal margin

Lumbar spine lateral →Lateral recumbent · 100 cm · centring point: L3, on the mid-coronal line at the lower costal margin

Lumbosacral junction lateral →Lateral recumbent · 100 cm · centring point: 3 cm below the iliac crest, on the mid-coronal line

Extra views

Lumbar spine lateral (after injury) →Supine · 100 cm · centring point: L3

Lumbar spine lateral in extension →Lateral, erect · 110 cm · centring point: L3

Lumbar spine lateral in flexion →Lateral, erect · 110 cm · centring point: L3

All views in this region

• Lumbar spine AP
• Lumbar spine lateral
• Lumbosacral junction lateral
• Lumbar spine lateral (after injury)
• Lumbar spine lateral in extension
• Lumbar spine lateral in flexion

Quick reference

Where to centre, how far and which receptor, for every l-spine view at a glance. Open a guide for the full set-up.

Mistakes that lead to repeats

• Spaces closed on the lumbar spine AP: flex the knees to flatten the back.
• Double posterior margins on the lumbar spine lateral: square the shoulders and hips.
• L5/S1 closed on the lumbosacral junction lateral: pad the waist so the spine is horizontal.
• Spine cut off on the lumbar spine lateral (after injury): centre the detector on the mid-coronal line.
• Patient unstable on the lumbar spine lateral in extension: let the patient hold the stand.
• Sacrum cut off on the lumbar spine lateral in flexion: centre lower in flexion.

Common questions

Which L-spine views are routine?

Usually Lumbar spine AP, Lumbar spine lateral and Lumbosacral junction lateral.

What distance (SID) do L-spine X-rays use?

Anywhere from 100 to 110 cm, depending on the view. Each guide gives the exact figure.

Do L-spine X-rays need a grid?

Yes, every view here is taken with a grid.

← All positioning regions