What is the angle between the MSP and the plane of the IR from a lateral position for the Parieto orbital oblique projection for the optic foramen?

SKULLSKULL PLANES, POINTS & LINEMidsagittal plane (MSP)Interpupillary line (IPL)AcanthionOuter canthusInfraorbital marginExternal acoustic meatus (EAM)Orbitalmeatal line (OML)Infraorbitomeatal line (IOML)/FrankpurtLineAcanthiomeatal line (AML)Mentomeatal line (MML)Between OML & IOML: 7odifferenceBetween OML & GML: 8odifferencePATHOLOGY1. ) Basal FxFx located at the base of the skull2) Blowout FxFx of the floor of the orbit3.) Contre-Coup FxFx to one side of a structure caused bytrauma to the other side4.) Depressed FxFx causing a portion of the skull to bedepressed into the cranial cavity5.) Le Fort FxBilateral horizontal fxs of the maxillae6.) Linear FxIrregular or jagged fx of the skull7.) Tripod FxFx of the zygomatic arch & orbital floor/rim& dislocation of the frontozygomatic suture8.) MastoiditisInflammation of mastoid antrum & air cells9.) Paget’s DiseaseThick, soft bone marked by bowing fxs10.) SinusitisInflammation of one or more of theparanasal sinuses11.) TMJ SyndromeDysfunction of the temporomandibular jointA.) SKULLPA PROJECTIONPP:Prone; forehead & nose against IR; MSP &OML perpendicular to IRRP: NasionCR:PerpendicularSS:Petrous pyramid completely filled the orbits;frontal boneAP PROJECTIONPP:Supine; MSP & OML perpendicular to IRRP: NasionCR:PerpendicularSS:Same as PA, but the image is MAGNIFIEDMODIFIED CALDWELL METHODPA AXIAL PROJECTIONPP:Prone; forehead & nose against IR; OMLperpendicular to IR; MSP perpendicular to IRRP:NasionCR:15ocaudadSS:-General Survey Examination:Anterior & side walls of the craniumTemporal fossaeFrontal sinuses & anterior ethmoid sinusCrista galliUpper 2/3 of orbitsPetrous pyramid to lower 1/3 of orbit-Superior orbital fissure/sphenoid fissure (20-25ocaudad) & foramen rotundum (25-30ocaudad)AP AXIAL PROJECTIONPP:Supine; OML perpendicular to IRRP:NasionCR:15ocephalad1

Rest lateral aspect of head against table or bucky surface w side of interest closest to IR.

Align MSP // to IR.
Align IPL perpendicular to IR.
Adjust chin to bring the IOML perpendicular to front edge of film.

Center CR to zygoma, midway between outer canthus & EAM. CR perpendicular to IR

Parietoacanthial Projection
(Waters Method)

Extend neck, resting chin against bucky.
Adjust head until MML is perpendicular to IR.
The OML will form 37* angle w bucky.
MSP perpendicular to the midline of grid.

Align CR perpendicular to IR, exit at acanthion.

PA Axial Projection
(Caldwell MEthod)

Rest nose and forehead against bucky.
Tuck chin, bringing IOML perpendicular to IR.
Align MSP perpendicular to midline of grid.

Angle CR 15* caudad, to exit at nasion.

True later w side of interest closest to IR.
Position nasal bones to center of IR.
Align MSP // w table.
Align IPL perpendicular to table.
Position IOML perpendicular to front edge of cassette.

Align CR perpendicular to IR.
Center 1/2" inferior to nasion

Submentovertex (SMV) Zygomatic Arches

Raise chin, hyperextend neck until IOML is // to IR.
Align MSP perpendicular to grid.

Align CR perpendicular to IR.
Center midway between zygomatic arches, 1 1/2" inferior to mandibular symphysis.
Center IR to CR w plane of IR // to IOML.

Oblique Inferosuperior (Tangential) Zygomatic Arches

Hyperextend neck until IOML is // to IR.
Rest head on vertex of skull.
Rotate head 15*, tilt chin 15* toward side of interest.

Align CR perpendicular to IR and IOML.
Center CR to zygomatic arch of interest (CR skims mandibular ramus, passes thru arch, and skims parietal eminence on downside).
Adjust IR so it is // to IOML and perpendicular to CR.

AP Axial Zygomatic Arches
(Modified Towne Method - "Jug Handle View")

Posterior skull against bucky.
OML (or IOML) perpendicular to IR.
Align MSP perpendicular to midline of the grid.

Angle CR 30* caudad to OML (or 37* to IOML).
Center CR 2.5cm superior to glabella (to pass thru midarches) at the level of the gonion.

Parietoorbital Oblique Optic Foramina
(Rhese Method)
"Three point landing position"

Pt prone w MSP perpendicular to IR.
AML is perpendicular to IR.
Chin, cheek & nose touching table.
Rotate 37* toward affected side.
Angle between MSP and IR will be 53*

Align CR perpendicular to IR at midportion of the downside orbit.

Axiolateral Oblique Mandible

True lateral w side of interest against IR.
Extend neck to prevent superimposition of gonion over C-spine.
Mandible // to IR.

Lateral demonstrates ramus
30* for body
45* for mentum
10-15* for general survey

Angle CR 25* cephalad from IPL;
for horizontal beam +5-10*
Combination tilt/CR not exceed 25*.
CR exit mandibular region of interest.

Rest forehead & nose against bucky.
Tuck chin, bringing IOML perpendicular to IR.
Align MSP perpendicular to midline of grid.

PA: align CR perpendicular to IR, centered to exit at junction of lips.

Opt. PA Axial: CR 25* cephalad, centered to exit at acanthion.

AP Axial Mandible
(Towne Method)

Rest pt posterior skull against bucky.
Tuck chin, bringing OML perpendicular to IR
(Or IOML and add 7* CR angle)
Align MSP perpendicular to midline of grid.

Angle CR 35-42* caudad.
Center CR to glabella.

Lateral aspect of head against bucky w side of interest closest to IR.
Align IPL perpendicular to IR.
Adjust chin to align IOML perpendicular to front edge of film.

Align a horizontal CR perpendicular to IR.
Center CR to a point midway between outer canthus & EAM.

PA Sinuses
(Caldwell Method)

Place nose & forehead against bucky w neck extended to elevate the OML 15* from horizontal.
Align MSP perpendicular to midline of grid.

Align CR horizontal.
Center to exit nasion.

Parietoacanthial Sinuses
(Waters Method)

Extend neck, placing chin & nose against talbe.
Adjust head until MML is perpendicular to IR.
OML will form a 37* angle w the plane of IR.
MSP perpendicular to midline of grid.

Align a horizontal CR perpendicular to IR.
Centered to exit at the acanthion.

Which three cranial bones articulate directly with the zygomatic bone?

Frontal, sphenoid, temporal

What is the only paranasal sinus not contained w/in a cranial bone?

The ___ sinuses develop last and are not fully developed until the teenage years.

A fracture involving the facial bones where a blow to one side causes a fracture to the opposite side is termed

T/F: For a lateral facial bones projection, the chin should be adjusted so the IOML is perpendicular to the front edge of the IR.

Which positioning line is placed perpendicular to the IR for the parietoacanthial projection?

Where does the CR exit for a modified parietoacanthial (modified Waters) projection of the facial bones?

Which projection will best demonstrate the bony nasal septum?

Which positioning line must be used with a 30* caudad angle for an AP axial projection of zygomatic arches?

Where is the CR centered for an AP axial projection for the mandible?

Which sinuses are best demonstrated with a parietoacanthial projection?

A radiograph of a lateral projection of the facial bones reveals that the mandibular rami are not superimposed. What specific positioning error is present on this radiograph?

A radiograph of a parietoacanthial (Waters) projection reveals that the petrous ridges are superimposed over the lower 30% of the maxillary sinuses. What specific positioning error (if any) led to this radiographic finding?

A radiograph of an axiolateral projection of the mandible w the head in a lateral position reveals that the mandibular body is greatly foreshortened. What modification is needed to produce a more diagnostic image?

Increase the rotation of the skull toward the IR

Which two bones form the bony nasal septum?

The posterior aspect of the orbit is termed the

T/F: The lateral projection of the facial bones is a unilateral projection. (Right and left laterals are generally not required)

T/F: For a lateral facial bones projection, the chin should be adjusted so the IOML is perpendicular to the front edge of the cassette.

Where is the CR centered for a lateral projection of the facial bones?

Zygoma, midway between the EAM and the outer canthus

What is the angle between the OML and the plane of the IR for the parietoacanthial (Waters) projection?

T/F: The modified parietoacanthial (modified Waters) projection requires more extension of the head and neck as compared to the parietoacanthial (Waters) projection.

Which positioning line is placed perpendicular to the plane of the IR for the parietoacanthial projection?

T/F: The 15* PA Axial (Caldwells) projection produces an unobstructed view of the maxilla.

Where does the CR exit for a modified parietoacanthial (modified Waters) projection of the facial bones?

Which positioning line is placed perpendicular to the plane of the IR w a true lateral nasal bone projection?

What projection will best demonstrate the bony nasal septum?

T/F: The lateral projection for the nasal bones is generally a unilateral projection. (Both right and left laterals are usually not required)

What can the tech do if the patient cannot extend the head & neck adequately for the routine SMV projection of the zygomatic arches?

Angle the CR to place it perpendicular to the IOML

Which positioning line is parallel to the IR for the oblique inferosuperior (tangential) projection of the zygomatic arches?

Which projection best demonstrates the floor of the orbits?

Modified parietoacanthial
(modified Waters)

Which positioning line must be used with a 30* caudad angle for an AP axial projection of zygomatic arches?

Which positioning line is placed perpendicular to the IR for the parieto-orbital projection of the optic foramina?

The proper name for the parieto-orbital projection is the

T/F: routine optic foramen studies are routinely taken as bilateral projections.

How much cephalad CR angulation is required for the axiolateral projection of the mandible?

25*

10-15* for general survey

30* - body

45* - body

How much skull rotation (from a lateral position) is required to place the ramus parallel to the IR for the axiolateral projection of the mandible?

Which positioning line is perpendicular to the IR for a PA projection of the mandible?

Which aspect of the mandible is best demonstrated w an AP axial projection CR angled 40* caudal?

Where is the CR centered for an AP axial projection for the mandible?

What CR angle is required for the AP axial projection for the TMJs with the IOML perpendicular to the IR?

The modified Law method for TMJ requires a ___ rotation of the skull and a ___ angle of the CR.

What is the position of the skull for a Schuller method projection of the TMJs?

What CR angle is required for the Schuller method projection of the TMJs?

A radiograph of a lateral projection of the facial bones reveals that the mandibular rami are not superimposed. What specific positioning error is present on this radiograph?

A radiograph of a parietoacanthial (Waters) projection reveals that the petrous ridges are superimposed over the lower 30% of the maxillary sinuses. What positioning error led to this?

A radiograph of a modified parietoacanthial projection reveals that the petrous ridges are projected into the lower half of the maxillary sinuses. What modifications should be made?

Nothing; accept the radiograph

A radiograph of an axiolateral projection of the mandible for the mandibular body is rotated how many degrees from lateral?

A pt enters the ER w a possible nasal bone fx. The physician is concerned about a possible bony nasal septum deviation, as well as fractured nasal bones. Which routines would best diagnose these injuries?

Parietoacanthial, lateral nasal bone, and superinferior (axial) projections

A patient enters the ER w a possible fx of the R zygomatic arch. What routines?

Submentovertex, bilateral oblique tangential, and AP axial projections

Where does the CR exit for a PA axial projection of the mandible?

A radiograph of a parieto-orbital projection for the optic foramen reveals that the optic foramen is projected into the inferior orbital rim. What should be changed?

Decrease the extension of the head and neck