skull projections Flashcards
- pt nose and forehead againsr rhe bucky surface
- OML perpendicular to IR
- MSP perpendicular to midline of table
- CR is perpendicular to IR, centered and exits at Glabella
- SS: Frontal bone, crista galli, frontal and anterior ethmoidal sinuses, greater and lesser wing of sphenoid, Petrous Ridges fill the orbits
PA Projection
- pxn’s nose and forehead against the Bucky surface
- OML perpendicular to IR
- CR: 15° caudad, to exit at Nasion
- SS: Petrous Ridge being projected into the lower 1/3 of the orbits, Frontal Bone, Orbital Rim, Anterior Ethmoidal Air Cells
PA Axial Projection/ Caldwell Method
- head in a true lateral position with the pxn’s body as oblique as needed for comfort
- MSP parallel to IR
- IPL perpendicular to IR
- IOML parallel to IR
- CR is perpendicular IR, 2 inches superior to EAM
- SS: superimposed cranial halves with the lateral details closest to the IR are demonstrated, the sella turcica and clivus
Lateral Projection
- for trauma patients
- demonstrate airfluid levels in the sphenoid sinus, this finding maybe the clue to the presence of basal skull fracture
- demonstrate the Sella Turcica CR must be perpendicular to IR, directed ¾ inch anterior and ¾ inch superior to EAM.
Cross Table Lateral
- Depress the pxn’s chin, bringing OML perpendicular to IR
- CR 30° caudad to OML, or 37° caudad to IOML
- RP: 2.5 inches above the Glabella
- SS: Occipital bone, petrous pyramids, and foramen magnum, with the dorsum sellae and posterior clinoids visualized in the shadow of the foramen magnum.
AP Axial Projection/ Towne Method
AP Axial Projection of the Cranium:
Towne
Grashey
Altschul
Chamberlain
- Head rested on the forehead and nose
- CR: 25° Cephalad, enters 1 ½ inch below the Inion and exits at 1 ½ inch above the Nasion
- SS: Sellar structures seen within the foramen magnum.
PA Axial Projection/ Haas Method
- hyperextend neck and raise chin until IOML is parallel to IR. rest the pt’s head on vertex.
- CR is perpendicular to IOML
- RP: ¾ inch anterior to level of EAM (midway between angles of mandible)
- SS: Base of the skull, foramen magnum, ovale and spinosum, mandible, hard palate, zygomatic arches, petrous ridges, ethmoid and sphenoid sinuses, and the occipital bone.
SubmentoVertico Projection/ Full Basal Projection /Schuller Method
- CR passes through a point ¾ inch anterior to the level of the EAM
VerticoSubmental Projection
CR Caldwell
15° caudad, to exit at Nasion
CR Towne
30° caudad to OML, or 37° caudad to IOML
CR Haas
25° Cephalad
RP Towne (skull)
2.5 inches above Glabella
RP Haas (skull)
enters 1 ½ inch below the Inion and exits at 1 ½ inch above the Nasion
RP Schuller (skull)
3/4 inch anterior to level of EAM
RP of Haas
1.5 inch below the Inion and exits at 1.5 inch above the Nasion
RP Cross Table Lateral
directed ¾ inch anterior and ¾ inch superior to EAM.