Exam category: Procedures → Head, Spine and Pelvis
Why it matters: Each region has one geometric fact that tells you which view opens which structure — the cervical foramina angle, the thoracic facet angle, the lumbar "Scottie dog." Learn the angle for each region and the whole spine falls out of it. The registry tests the one place students reliably flip: cervical-vs-lumbar obliques.
Every part of the spine has joints and openings that only show up when the beam lines up with them, so positioning is just "what angle opens this structure?" In the neck, the intervertebral foramina sit at 45°, so you oblique 45°. In the thoracic spine the facet joints sit at 70–75°, so you oblique steeper. In the lumbar spine a 45° oblique turns the vertebra into a little dog, and reading that dog is reading the anatomy. Sacrum, coccyx, SI joints, pelvis and hip are in Pelvis, hip & SI joints.
The whole cervical series comes from one idea: the foramina and the joints point in different directions, so different views open them.
| Structure | Angle to the midsagittal plane | View that opens it |
|---|---|---|
| Intervertebral foramina (C2–C7) | 45° oblique, angled ~15–20° inferior | 45° oblique + CR angle |
| Zygapophyseal joints (C2–C7) | 90° (straight lateral) | True lateral |
| Atlantoaxial joints (C1–C2) | — | AP open-mouth only |
Answer this to keep going. 16 more sections unlock below.
A student reasons that since the lumbar oblique opens the zygapophyseal joints, the cervical oblique must too. Which projection actually opens the C2 to C7 zygapophyseal joints?
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