Cranium Series Radiographic Positioning

Vocabulary flashcards covering routine and special projections, central ray angles, positioning lines, and evaluation criteria for cranium radiography.

Routine Cranium Series

A standard radiographic skull examination series consisting of AP axial (Towne), Lateral, and PA $15^\times$ (Caldwell), PA $25^\times$ to $30^\times$, or PA $0^\times$.

Special Cranium Series

Supplemental radiographic skull projections including PA axial (Haas) and SMV (submentovertex).

AP Axial (Towne Method) Positioning

A cranial projection where the CR is angled $30^\times$ caudad to OML or $37^\times$ to IOML, centered $2\frac{1}{2}\text{ inches}$ ($6.5\text{ cm}$) above the glabella.

AP Axial Evaluation Criteria

Radiographic criteria requiring the dorsum sellae projected within the foramen magnum, entire skull visualized, no rotation or tilt, symmetric petrous ridges, and optimal exposure factors.

Right Lateral Skull Positioning

Positioning where the MSP is parallel, interpupillary line is perpendicular, and CR is centered $2\text{ inches}$ ($5\text{ cm}$) superior to EAM.

Lateral Skull Evaluation Criteria

Radiographic criteria requiring the entire skull visualized, cranium seen without rotation or tilt, correct flexion and extension of skull, and optimal exposure factors.

PA $15^\times$ (Caldwell) Projection

A PA axial projection of the skull where the central ray is directed $15^\times$ caudad and exits at the nasion.

$0^\times$ PA Projection

A PA projection of the skull where the central ray is perpendicular ($0^\times$) and exits at the glabella.

PA $15^\times$ (Caldwell) Evaluation Criteria

Criteria requiring the entire skull visualized, no rotation, petrous ridges projected over the lower $\frac{1}{3}$ of orbits, and optimal exposure factors.

Petrous Ridges Criteria Comparison

Demonstrates that the petrous ridges are projected over the supraorbital margin in a $0^\times$ PA projection, and over the lower $\frac{1}{3}$ of orbits in a $15^\times$ Caldwell projection.