Procedures Exam #4 Flashcards

All headwork is done on what breathing instructions?

Suspended breathing

Lateral Skull Positioning (EAM line and centering)

IOML parallel to floor, center 2 inches superior to EAM

If your patient is hypersthenic and laying recumbent, how do you need to prop them up to keep the head in the same plane as the body? (eliminate tilt)

Prop the head up with a pillow (prop up the body if patient is hyposthenic)

What anatomy indicates a true lateral skull?

Orbital plates, sella turcica, rami of mandible are all superimposed as much as possible

PA Axial Caldwell Skull

1. Line OML perpendicular to board (forehead and nose on board)

2. angle 15 degrees caudad, exiting the skull at the level of the nasion

Where do the petrous ridges appear on a Caldwell skull projection?

lower 1/3 of the orbits

What sinus does the Caldwell skull projection best demonstrate?

frontal sinus

What is changed in the alternative PA Axial projection of the skull?

angulation of the CR is increased to 30 degrees (petrous ridges are thrown lower under the orbits and the skull looks more distorted)

PA Skull projection

1. OML perpendicular to board

2. CR exits at glabella, no CR angle (petrous ridges fill up the orbit)

AP Axial (Towne) Skull projection

1. OML perpendicular to the board

2. 30 degrees caudad angulation, CR enters 2.5 inches above the glabella (at hairline) (if using IOML, increase angulation to 37 degrees caudad)

What is the area of interest on a Towne Skull projection?

the dorsum sellae and posterior clinioid processes should be projected inside of the foramen magnum, can sometimes see the posterior arch of cervical vertebra inside

If the dorsum sellae is projected above the foramen magnum, the neck is _______

not flexed enough

If the dorsum sellae is projected below the foramen magnum, the neck is ______

flexed too much

The Haas method is a PA alternative to which projection

AP Axial Towne projection

Haas method PA Axial Projection

1. OML perpendicular to the board

2. CR exits 1.5 inches above nasion, angled 25 degrees cephalad

How does the Haas vary in appearance compared to a Towne projection

The foramen magnum is slightly magnified

SMV Skull Projection

1. IOML parallel to IR

2. CR has no angle, enters between the gonions

What sinuses can more easily be identified with an SMV projection?

1. Ethmoid

2. Sphenoid

Does AP or PA magnify the orbits more?

AP

Lateral Facial Bones Projection

1. CR enters half way between outer canthus and EAM

2. Must include the mandible (not necessary on skull projections)

What is the difference in a Caldwell for the skull and a Caldwell for facial bones?

collimation

Parietoacanthial Waters Facial Bones Projection

1. MML is positioned perpendicular to the IR

2. 37 degree angle is formed between the MML line and the OML line and the board

3. CR exits at acanthion

4. Petrous ridges are projected below the maxillary sinuses

Which sinuses are best demonstrated by the Waters projection?

maxillary sinuses

Modified Waters Projection

1. LML is perpendicular to IR

2. CR exits at acanthion

3. Petrous ridges are half way through the maxillary sinuses

Why is the modified Waters projection preformed?

distorts the orbits less than the normal Waters, demonstrates Blowout fractures the best

What cannot be done when doing any sinus projections?

using an angle on the tube

How is a Caldwell Sinus projection done?

The head is tilted so that the tip of the nose touches the board instead of angling the tube 15 degrees caudad (kept parallel to the floor)

Why is the Open Mouthed Waters preformed?

Opening the mouth allows for the viewing of the sphenoid sinus

Lateral Nasal Bones Projection

1. IOML perpendicular to front edge of IR

2. CR enters ½ inch distal to the nasion

3. Collimate to include all soft tissue

4. Do NOT use a grid

How is the Waters projection for nasal bones different than for facial bones

Collimation

How is the Caldwell projection for nasal bones different than for facial bones

Collimation

Orbits (Rhese Method)

1. AML perpendicular to IR

2. 3 point landing (cheek, nose, brow)

3. MSP rotated 53 degrees towards IR

4. CR exits the downside orbit

5. ordered bilaterally

How is the Waters/modified Waters method different when done for orbits?

Center between orbits, collimate to orbits

Caldwell (PA Axial) Orbits

1. OML perpendicular to IR

2. CR angled 30 degrees caudal, exits at mid orbits (3/4 inch distal to nasion)

How is a lateral orbits different than other lateral headwork projections?

1. center to the outer canthus

2. collimate to orbits

Modified Towne TMJ Projection

1. OML perpendicular to IR

2. 35 degree caudal angle

3. CR enters 3 inches superior to nasion

(best for assessing the interaction between the condyle of the mandible and the mandibular fossa)

(done open/closed mouth)

Mod. Law TMJ projection (axiolateral oblique)

1. IOML parallel to floor

2. 15/15 (rotate head towards IR 15 degrees, angle CR 15 degrees caudad)

3. CR enters 1 ½ inches superior to upside EAM

(open/closed mouth)

Schuller TMJ Projection (axiolateral)

1. Head in TRUE LATERAL position

2. IOML parallel to floor

3. Angle CR 25-30 degrees caudad

4. CR enters ½ inch anterior and 2 inches superior to upside EAM

(open/closed mouth)

PA mandibular rami

1. OML perpendicular to IR

2. CR exits at/near acanthion

PA Axial mandibular rami

1. OML perpendicular to IR

2. CR angled 25-30 degrees cephalad

3. Exits at acanthion

PA mandibular body

1. AML perpendicular to IR

2. CR exits at lips

PA Axial mandibular body

1. AML perpendicular to IR

2. CR exits at acanthion, 30 degree cephalad angle

Axiolateral mandibular rami

1. TRUE LATERAL

2. CR angled 25 degrees cephalad (enters at gonion)

Axiolateral Oblique mandibular body

1. 30 degree rotation towards IR

2. 25 degree cephalad angle, enters at gonion

Axiolateral Oblique mandibular symphysis

1. 45 degree rotation towards IR

2. 25 degree cephalad CR angle, enters at gonion

AP Axial Towne mandible

1. OML perpendicular to the IR

2. 35 degree caudad angle

3. enters 1 inch above the glabella

SMV mandible

1. CR perpendicular to IOML, enters between gonions (IOML parallel to IR)

Zygomatic arches SMV

1. IOML parallel to IR

2. Enters 1 inch posterior to outer canthus

(produces jug handle appearance)

AP Axial Towne Zygomatic Arches

1. OML perpendicular to IR

2. CR 30 degrees caudad

3. Enters on glabella

Zygomatic arch (unilateral) tangential

1. IOML parallel to IR

2. Rotate towards affected side 15 degrees

3. Tilt away from affected side 15 degrees

4. CR enters 1 inch posterior to outer canthus