How many degrees and in which direction should the central ray be directed for the PA axial projection Haas method of the skull?

The skull consists of 22 bones:
8 cranial bones
- frontal
- 2 parietal
- 2 temporal
- sphenoid
- ethmoid
- occipital

14 facial bones
- 2 maxillary
- 2 zygomatic
- 2 nasal
- 2 lacrimal
- 2 inferior nasal conchae
- 2 palatine
- vomer
- mandible

Caldwell's Method
Towne's Method
Rhese's Method
Water's Method

etc.

What is the border that receives the roots of the teeth?

What is the outer opening of the ear called?

EAM - External Auditory Meatus.

The junction of the upper and lower borders of the orbits at the lateral margin is:

The ___ is found at the junction of the upper lip and nose.

Located 1/2" below the glabella. 

The angle of the mandible is known as:

The smooth raised portion between the supercillary arches is the:

Describe the glabellomeatal base line (GML). 

Extends from glabella to the EAM.

Describe the orbitomeatal base line (OML).

- Extends from the outer canthus of the eye to the EAM. - There are 8 degrees difference between the GML & the OML. - Utilize this baseline whenever you rest the head on the forehead and nose OR duck the chin DOWN!

Describe the infraorbitomeatal base line (IOML).

- Extends from the infraorbital margin to the EAM. - There are 7 degrees difference between the IOML & the OML. - Use this baseline whenever the head is level OR when you're doing a submentovertical (SMV) projection.

Describe the acanthiomeatal base line (AML).

Extends from the Acanthion to the EAM. Use this baseline when the head is extended.

Describe the mentomeatal base line (MML).

Extends from the mentum to the EAM. Use this baseline when the head is extended.

Describe the interpupillary base line (IPL).

Extends between the pupils.

Describe the glabelloalbeolar base line (GAL).

Extends between the glabella & the alveolar ridge of the maxilla.

The ___ base line is also called Reids base line. The ___ base line is also called the Radiographic base line.

- Infraorbitomeatal (IOML). - Orbitomeatal (OML).

Which base line is perpendicular to the film in the lateral projection?

Which base line is parallel to the transverse axis of the film in the lateral projection?

How is the central ray directed & centered for the lateral projection?

Perpendicular to the IR. Enters 2" above EAM.

For a severely traumatized patient, how would you adjust the lateral projection?

Cross table lateral projection.

The head rests on the ___ for a lateral projection.

The head rests on the ___ for the PA projection.

What base line and plane are perpendicular for the PA projection?

Midsagittal plane & Orbitomeatal line.

To demonstrate the frontal bone, the CR is ___ to the film. The petrous ridges fill:

- Perpendicular. - Fill orbits.

To demonstrate a general survey of the skull in the PA projection, the CR is ___ & the petrous ridges ____.

- Angled 15 degrees CAUDAD. - In lower 1/3 of orbits.

To demonstrate the superior orbital fissures, the CR is ___ & the petrous ridges ___.

- 20-25 degrees CAUDAD. - @ lower margin of orbit.

To demonstrate the foramina rotundum, the CR is ___ & the petrous ridges ___.

- 25-30 degrees CAUDAD. - Below orbit.

The Grashey-Towne method is an ___ projection.

How are the orbitomeatal baseline and the median plane to the film for the Grashey-Towne method?

Both perpendicular to the IR.

If the head cannot be ducked, the ___ baseline can be used. The CR is then angled ___.

- IOML. - 37 degrees CAUDAD.

For the routine AP Axial projection, the CR is ___.

For demonstration of the foramen magnum & the jugular foramen, the CR is ___.

The Grashey method will demonstrate:

- Petrous ridges. - Foramen magnum. - Dorsum sella. - Posterior clinoid processes. - Occipital bone. - Mastoids. - Posterior portion of parietal bones.

The PA Axial projection is a ___ method.

The Haas method is a reverse ___ method.

Reverse Grashey-Towne method.

The PA Axial projection (Haas method), the CR is angled ___ degrees ___. Direction to a point ___ inches above the ___.

- 25 degrees CEPHALAD. - 1 & half inches above the NASION.

Why was the Haas method devised?

To move shoulders out of the way on obese patients. 

The Valdini method is a ___ projection.

The Valdini method best demonstrates the ___ because of the absence of ___.

- Organs of hearing. - Absence of distortion.

The submentovertical & verticosubmental projections are ___ methods.

For the submentovertical projection, the ___ baseline is as nearly parallel to the film as possible. The CR is ____ to the ____ baseline.

- IOML. - @ right angles. - IOML.

What structures are demonstrated in a full basal projection (SMV/Schuller method)? Full axial (basalar view of cranium); shows axial of bottom of skull.

- Petrous ridges. - Mastoids. - Basal foramina. - Sphenoid sinuses. - Nasal septum. - Odontoid processes. - Mandible.

What facial bones can be demonstrated in the submentovertical projection?

The patient is in the ___ position for the verticosubmental projection. The head rests on the:

For the lateral projection of the sella turcica, the CR is directed to:

The AP axial projection with the CR directed 30 degrees CAUDAD will demonstrate ____. With the CR directed 37 degrees CAUDAD will demonstrate ____.

For the PA projection of the sella turcica, the head is adjusted so that the base line is perpendicular. The CR is angled ___ to the head, it will demonstrate.

Lower border of the orbit.

Round prominence of the chin.

Mental point/Mentum/Mental Protuberance.

External occipital protuberance; prominence of the back of the skull.

Round prominence on the upper portion of the parietal bone.

Plane that divides the body into equal right and left halves.

Median sagittal plane (Median).

Plane that divides the body into anterior and posterior; extends through coronal suture.

Wide skull side to side; petrous ridges form a ___ degree angle with the median sagittal plane.

- Brachycephalic. - 54 degrees.

Narrow skull side to side; petrous ridges form a ___ degree angle.

- Dolichocephalic. - 40 degree angle.

Average skull; petrous ridges form a ___ degree angle.

- Mesocephalic. - 45-47 degree angle.

An AP axial (Grashey-Towne method) of the skull is obtained. The dorsum sellae is projected below the foramen magnum, but the anterior arch of C1 is visible within the foramen magnum. What positioning error led to this?

A submentovertical projection of the skull is obtained. The mandibular condyles are projected onto the petrous ridges. What led to this error?

The head was not extended enough. To correct it, extend the head more OR angle tube more so that the CR is perpendicular to the IOML.

A lateral projection of the skull is obtained. The orbital plates are not superimposed, one is slightly superior to the other one. What positioning error led to this?

A patient has a possible basilar skull fracture. Rountine projections are PA, lateral, AP Axial (Grashey-Towne). What modifications would you do for this patient? What projection best demonstrates a basilar skull fracture?

- AP instead of PA; AP Axial (Grashey-Towne) & cross table instead of lateral. - Cross table lateral.

An AP Axial (Grashey-Towne method) of the skull needs to be obtained. The patient is unable to flex his head enough so that the OML is perpendicular to the IR. What should you do to compensate for this problem?

Use the IOML & increase the CR angle by 7 degrees. CR angled 37 degrees CAUDAD.

How many degrees and in which direction should be central ray be directed for Haas method?

What is the average central ray angulation for the PA axial Haas projection of the skull?

When taking a PA axial projection Caldwell method of the skull the central ray is directed?

Where is the central ray directed for an anteroposterior axial projection of the skull?