What does a thoracic oblique projection visualize and what is the typical rotation?

• A. Visualizes pars interarticularis; rotate about 15 degrees
• B. Visualizes intervertebral discs; rotate 0 degrees
• C. Visualizes zygapophyseal joints and foramina; rotate about 45 degrees
• D. Visualizes pedicles; rotate 60 degrees

Answer: (C)

Opening the thoracic spine obliquely serves to bring the zygapophyseal joints and the foramina into profile. About 45 degrees of rotation is used because this angle best separates the joints and opens the foramina for evaluation, giving a clear view of their anatomy and any degenerative or traumatic changes. Intervertebral discs aren’t visible on plain radiographs, so that option isn’t the goal here, and the thoracic oblique isn’t primarily about visualizing pedicles or pars interarticularis—the latter is more a focus in other regions. So the correct idea is that this view shows the zygapophyseal joints and foramina with a rotation of roughly 45 degrees.