Ch. 11 F.B., Nasal, and Orbits Workbook Flashcards
a radiograph of a lateral projection of the facial bones shows the mandibular rami are not superimposed. what positioning error led to this
rotation of skull
for the superoinferior projection of the nasal bones, the IR is placed perp to what line
glabelloalveolar line (GAL)
what CR angle must be used to project the petrous ridges just below the orbital floor with the PA axial (caldwell method) projection
30 degrees
what FB projection best demonstrates inferior orbital rim, maxillae, nasal septum, nasal spine, zygomatic bone and arches
parietoacanthial projection
a radiograph of a parietoacanthial (waters) projection shows the petrous ridges are projected within the maxillary sinuses. is this an acceptable image? if not, what must be done to improve the image during the repeat
no, petrous ridges should be just below the maxillary sinuses. patient’s head needs to be extended more
a radiograph of a superoinferior projection of the nasal bones shows the glabella are superimposed over the nasal bones. what positioning error led to this and how can it be corrected
excessive flexion of the head and neck or incorrect CR angle; CR must be parallel to the GAL
a radiograph of a parietoacanthial projection shows the distance between the msp and the outer orbital margin is not equal. what positioning error is present
rotation of skull
a radiograph of a 30 degree PA axial projection of the facial bones shows the petrous ridges are projected at the level of the inferior orbital margins. is this an acceptable image for this projection. if not, what must be bone to improve the quality of the image during repeat
yes, this image meets evaluation criteria for a 30 degree PA axial
list the proper method name and the common descriptive name for the parietoacanthial oblique projection for the optic foramen
- rhese method
- three-point landing
a patient comes to the radiology department with a clinical history of a deviated nasal septum. which facial bone projection best demonstrates the degree of deviation
PA, PA axial, and parietoacanthial
what are two differences between the lateral projection of the cranium and the lateral projection for the facial bones
- IR is placed in portrait for facial bones and landscape for cranium
- CR is to the zygoma for facial bones and 2” above the EAM for the cranium
what is another term for the second cranial nerve
optic nerve
as part of a study of the zygomatic arches, the tech attempts to perform the smv position, due to the size of the patients shoulders, they are unable to flex their neck adequately to place the ioml parallel to the IR. what other options does the tech have to produce an acceptable smv projection
angle CR to placer it perp to ioml. angle the IR to maintain a perp relationship
which of the following is not a facial bone
- middle nasal conchae
- vomer
- lacrimal bone
- mandible
middle nasal conchae
which facial bones are sometimes called the “cheekbones”
zygomatic or malar bones
what facial bone projection best demonstrates bilateral zygomatic arches
smv projection
which facial bone is associated with the tear ducts
lacrimal bones
which of the processes of the maxilla is considered most superior
frontal process
vertical portion of mandible
ramus
which facial bones form the posterior aspect of the hard palate
horizontal portion of the palatine bones
a ‘free-floating’ zygomatic bone is the frequent result of what fracture
tripod
which facial bone structures are best seen with a parietoacanthial projection
orbits including infraorbital rims, bony nasal septum, maxillae, zygomatic bones and arches
give 2 reasons why projections of facial bones are performed PA rather than AP when possible
- reduces OID of facial bones
- reduces exposure to anterior facial bones and neck structures such as thyroid glands
T/F - both oblique inferosuperior (tangential) projections for the zygomatic arch are generally taken for comparison
true
what is the proper method name for the parietoacanthial projection of the facial bones
waters method
which specific facial bone structures (other than the mandible) are best demonstrated with the smv projection if the correct exposure factors are used (soft tissue tech)
zygomatic arches
the modified parietoacanthial (modified waters) projections requires what line to be perp to the IR. which also places the oml at what angle to the tabletop and IR
- lips-meatal line
- 55 degrees
mandibular angle
gonion
posterior process of the upper ramus
condyloid process
T/F - the oblique inferosuperior (tangential) projection for the zygomatic arch require that the skull be rotated and tilted 15 degrees away from the affected side
false - toward
a patient with a possible fracture of the nasal bones enters the ER, the physician is concerned about deviation of the nasal septum along with possible fracture of nasal bones, what radiographic routine would be best for this
patietoacanthial and right and left lateral projections
T/F - facial bone studies should always be performed recumbent whenever possible
false - best to perform erect
where does the Cr exit for a 15 degree PA axial (caldwell) projection for the facial bones
nasion
which two cranial bones articulate with the maxilla
frontal and ethmoid
a radiograph of a parietoacanthial (waters) projection shows the distance between the lateral margins of the orbits and the lateral aspect of the cranial cortex is not equal. what positioning error led to this
rotation of skull
from anterior to posterior, the cone-shaped orbits project upward at an angle of what and toward the msp at an angle of what
- 30 degrees
- 37 degrees
what is the largest immovable bone of the face
maxilla
what are the 3 aspects of the face that should be in contact with the head unit or tabletop when beginning positioning for the parieto-orbital oblique projection
- cheek
- nose
- chin
T/F - MRI is an excellent imaging modality for the detection of small metal foreign bodies in the eye
false
what is the term for the chin
mentum
T/F - nuclear medicine is not helpful in diagnosing occult facial bone fractures
false
bony process located anterior to mandibular notch
coronoid process
where is the CR centered for a lateral position for the facial bones
zygoma
which soft tissue landmark is found at the base of the anterior nasal spine
acanthion
a deviated nasal septum is most likely to occur at the junction between what
septal cartilage and vomer (pushed laterally to one side)
what facial bone projection best demonstrates the view of single zygomatic arch
oblique inferosuperior projection
list the 4 processes of the maxilla
- frontal
- zygomatic
- alveolar
- palatine
point of union between both halves of the mandible
symphysis menti
what is the major disadvantage of performing a straight PA projection for facial bones, with no CR angle or neck extension as compared to other PA facial bone projections
dense petrous pyramids superimpose the orbits, obscuring facial bone structures
a patient with a possible blowout fracture of the right orbit enters the ER. In addition to the basic facial bone routine, what single projection would best demonstrate this type of injury
modified parietoacanthial (modified waters method) projection
a lateral radiograph of the facial bones demonstrates the bodies of the mandible are not superimposed one is about 1 cm superior to the other. how would this be corrected on a repeat
head was tilted, ensure the msp is parallel to the IR
which structures specifically are better visualized on the modified parietoacanthial (waters) projection as compared with the basic waters projection
orbital rims and orbital floors
T/F - an increase in kVp of 25%-30% (using manual techniques) is often required for the geriatric patient with advanced osteoporosis
false
where does the CR exit for a parietoacanthial (waters) projection of the facial bones
acanthion
T/F - CT is ideal for facial bone studies because it allows for the visualization of bony structures as well as related soft tissues of the facial bones
true
what facial bone projection best demonstrates the optic foramen
parieto-orbital oblique projection
a patient with a possible fracture of the left zygomatic arch enters the ER. neither the AP axial nor the smv projection demonstrates the left side well. the radiologist is indecisive as to whether this zygomatic arch is fractured. what other projection can the tech provide to better define this area
oblique inferosuperior (tangential) projections - these demonstrate depressed fractures of the zygomatic arch (bilateral usually taken for comparison)
a radiograph of a parietoacanthial projection (waters method) shows the petrous ridges are projected just below the maxillary sinuses. what positioning error (if any) is present
none - petrous ridges should be below the floors of the maxillary sinuses on parietoacanthial
horizontal portion of mandible
body
which of the facial bone openings is formed by a cleft between the greater and lesser wings of the sphenoid bone
superior orbital fissure
T/F - the right and left nasal bones form the largest part of the nose
false - most of the nose is composed of cartilage
where is the CR centered for an AP axial projection for the zygomatic arches
1” superior to nasion to pass through mid-arches (at level of gonion)
what facial bone projection best demonstrates profile image of nasal bones and nasal septum
lateral (nasal bones)
T/F - the common basic PA axial projection for facial bones requires a 15 degree caudal angle of the CR, which projects the dense petrous ridges into the lower 1/3 of the orbits
true
which of the following bones does not articulate with the zygomatic bone
- temporal
- mandible
- frontal
- sphenoid
mandible
U-shaped notch
mandibular notch
what facial bone projection best demonstrates the floor of the orbits (blowout fracture)
modified waters method
a radiograph of a parieto-orbital oblique (Rhese) projection shows the optic foramen is located in the upper outer quadrant of the orbit. is this an acceptable image for this projection? if not, what must be done to correct this on the repeat
no, increase extension of the head and neck. the AML should be perp to the IR to ensure the optic foramen is open and projected in lower outer quadrant of orbit
what is the name of the fracture that results form a direct blow to the orbit leading to a disruption of the inferior orbital margin
blow-out fracture
a patient with a clinical history of sinusitis comes to the radiology department for a sinus study . the patient is quadriplegic and cannot be placed erect. what single projection demonstrates any possible air-fluid levels in the paranasal sinuses
horizontal beam lateral projection
for a parietoacanthial (PA waters) projection the petrous ridges should be projected directly below what and projected into the lower half of the maxillary sinuses or below what for a modified waters projection
- maxillary sinus
- inferior orbital rims
which facial bone opening has the maxillary branch of the 5th cranial nerve passing through it
inferior orbital fissure
T/F - lateral projections for nasal bones generally are taken bilaterally for comparision
true
a radiograph of an smv projection for paranasal sinuses shows the distance between the mandibular condyles and lateral border of he skull is not equal. what positioning error is present
tilt of the skull
the parietoacanthial (waters) projection for the facial bones has what line perp to the IR, which places the OML at what angle to the tabletop and IR
- mentomeatal line
- 37 degrees
the purpose of this is to divide the nasal cavity into compartments and to circulate air coming into the nasal cavities
conchae/turbinates
for the parieto-orbital oblique projection the final angle between the msp and the IR should what and with what line perp to the IR. this places the optic foramen in what quadrant of the orbit
- 53 degrees
- acanthiomeatal line
- lower outer
