Abdominal CT: spinal fractures

Trauma patients undergoing imaging should always be evaluated for spinal fractures.

Diagnosing spinal fractures

In younger patients, spinal injuries are usually caused by significant trauma. In contrast, an older patient with osteoporosis can have a serious spinal injury from just a minor fall.

Sagittal view

When evaluating the spine for fractures, the highest yield view will be the sagittal images in bone windows. Here you can see how the vertebral bodies stack up (pun intended) by comparing them to each other and making sure they have normal alignment. We also make sure the vertebral bodies are similar in height and evaluate the spinous processes.

Articular pillar view

In the articular pillar view, we examine the posterior elements including the pedicles and articular pillars to make sure they are normally aligned.

In a motor vehicle collision, a flexion-type injury is most common in the lower thoracic and lumbar spine. This results in two changes:

• Wedging: compression of the anterior vertebral bodies
• Distraction: pulling apart of the posterior elements

---

Example Cases

Example 1: Compression fractures, fragmentation, and wedging

Compression fractures and fragmentation of two lumbar vertebral bodies anteriorly with some height loss and wedging compared to the other normal vertebrae.

---

Example 2: Wedging and split spinous process

As most patients have five lumbar vertebral bodies, you can count upward from the sacrum to help identify the level of injury: L5, L4, L3, L2, and L1.

In the next example, there is dramatic height loss and wedging of the first lumbar (L1) vertebra. The L1 fracture line extends through the articular pillar.

The image below from the same patient shows that the fracture splits the spinous process apart. This is an unstable injury where ligaments are also usually injured, but we cannot see these well on CT imaging. Some patients may require further imaging with magnetic resonance imaging (MRI) to specifically look for ligamentous and spinal cord injury.

---

Example 3: Abdominal aortic injury

Note that abdominal aortic injury is uncommon, even with high velocity trauma. However, the same blunt forces that cause a flexion injury to the spine can also injure the abdominal aorta and cause a traumatic dissection or pseudoaneurysm.

For this reason, you should carefully evaluate the aorta near the level of the injury for subtle signs of damage such as surrounding blood, wall thickening, and intimal tear. The case below has a flexion injury of the lumbar spine with retropulsion of a fragment of bone into the spinal canal and pulling apart of the posterior elements.

On the axial images below, we can see an injury to the abdominal aorta just below the spinal injury. This is characterized by a thickened, injured aortic wall, which indicates that there is an intramural hematoma. In the image on the right, you can see a small dissection flap in the lumen.

---

Case study: Osseous and ligamentous injury

More practice with complex spinal injuries by examining an additional case of trauma following a high-speed motor vehicle collision. The patient is presenting with severe back pain after the collision. We will look at the dedicated reformatted images of the lumbar spine, which help create a zoomed-in view of the spine.

---

References

• Top 100 CT scan quiz. LITFL

Radiology Library: Abdominal Trauma. Musculoskeletal injuries

• Hartung MP. Abdominal Trauma: rib fractures
• Hartung MP. Abdominal CT: spinal fractures
• Hartung MP. Abdominal CT: body wall injuries
• Hartung MP. Abdominal CT: pelvic fractures
• Hartung MP. Abdominal CT: bladder injuries

---