Spine and Pelvis
29 Thoracic Spine
Anatomy
body, vertebral arch, vertebral foramen, intervertebral disks, transverse processes, spinous process, laminae, pedicle, superior articular process, inferior articular process, zygapophyseal joints (AKA. apophyseal jts. or interarticular facet joints), facet or demifacet, costovertebral joint, costotransverse joints, intervertebral foramina.
Projections
[Part], PA or AP
CR Location
[Part], PA or AP –
Evaluation Criteria
AP Image Criteria: C7 to L1 should be seen centered to image. Good collimation should be visible. Sternoclavicular joints should be equidistant from the spine indicating no rotation.
Lateral Image Criteria: C7 to L1 well visualized and midline of image. Upper vertebra may be under exposed due to shoulders. Vertebral bodies in lateral profile (no rotation). Intervertebral disk space open (good support under waist). Ribs and lung markings will be blurred out if breathing technique is used.
Cervicothoracic (Swimmer’s or Twining) Lateral Image Criteria: C4 to T3 well visualized. Vertebral bodies in lateral profile (no rotation). Humeral heads separated vertically (because of tube angle). Intervertebral disk spaces well visualized.
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Hows & Whys of [Part] Radiography
- How many thoracic vertebrae are there?
- 12
- What should you do to obtain a more uniform density when doing a lateral thoracic spine?
- Use compensating filters or a saline bag on the neck, also reduce scatter with a strip of lead along the back.
- To demonstrate the upper three thoracic segments without superimposition of the shoulder, which projection would be done?
- Cervicothoracic Lateral
- What are the two common names of the above projection?
- Swimmer’s or Twining
- How should the patient be instructed to breath for a lateral T-spine? Why?
- The patient should breath gently if a breathing technique is used because very large breaths can cause too much motion, but too shallow breaths will not blur ribs enough.
- Which kind of curve does the thoracic spine have?
- The thoracic curve is a kyphotic curve, one of the primary spinal curves.
- Which projection of the thoracic spine best demonstrates the intervertebral foramina?
- Lateral
- Which projection of the thoracic spine best demonstrates the zygapophyseal joints?
- A 70º oblique, Upside for posterior obliques, Downside for anterior obliques.
- What are facets and demifacets?
- They are the areas where the ribs contact the vertebral body. If it contacts in one spot it is a facet, if it contacts in two places it is a demifacet. The rib and the facet or demifacet of the vertebra form a costovertebral joint.
- What are costotransverse joints?
- They are the area on the spinous processes of the first ten thoracic vertebrae, where the tubercle of each rib articulates. Ribs 11 and 12 articulate only at the costovertebral joints.
- What kind of joints are the costovertebral and costotransverse joints?
- Diarthrodial, Gliding