Spine and Pelvis
31 Lumbar Spine
Anatomy
superior articular process, transverse process, pedicle, pars interarticularis, lamina, inferior articular process, zygapophyseal joint. spinous process, superior vertebral notch, inferior vertebral notch, mamillary process, body, vertebral foramen, and intervertebral foramen.
Projections
[Part], PA or AP
CR Location
[Part], PA or AP –
Evaluation Criteria
AP Image Criteria: T12 to S1 should be seen centered to image. Good collimation should be visible. Sacroiliac joints should be equidistant from the spinous processes indicating no rotation. Spinous processes should be midline of the vertebral column.
Posterior Obliques Image Criteria: T11 to S1 well visualized and midline of image. Scotty dogs and open zygapophyseal joints should be seen on all five vertebrae. Pedicle (scotty’s eye) should be near the center of the vertebral body indicating correct obliquity.
Lateral Image Criteria: T12 to S1 well visualized. Vertebral bodies in lateral profile (square) indicates no rotation. Intervertebral foramina and Intervertebral disk space should be open.
Lateral L5 – S1 Spot Image Criteria: L5 – S1 joint space well visualized and in center of image. Vertebral bodies in lateral profile (no rotation). Intervertebral disk space open (proper tube angulation).
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Hows & Whys of Lumbar Spine Radiography
- How many lumbar vertebrae are there?
- 5
- What makes the lumbar vertebrae different from the thoracic or cervical vertebrae?
- Lumbar vertebra are larger, have smaller transverse processes, the spinous processes are larger and more blunt. The tip of the spinous process that can be felt is in line with the intervertebral disk space inferior to the vertebral body.
- What is the special name for the area of the laminae lying between the two articular processes?
- Pars interarticularis.
- Which Lumbar projection best demonstrates the intervertebral foramina?
- Lateral.
- Which Lumbar projection best demonstrates the zygapophyseal joints?
- 45º Oblique.
- What is the condition where the front part of one vertebra slips forward on the vertebra below it?
- Spondylolisthesis.
- What is the condition where the laminae fail to unite at the center line, leaving an opening where the spinous process is usually found?
- Spina bifida.
- What is the smoothly rounded projection on the back of each superior articular process?
- Mamillary process