Anatomy workbook-skull Flashcards
What is best demonstrated in a lateral skull view?
The entire crainium
What is best demonstrated in this image?
Superior orbital fissures and frontal bone
What is best demonstrated in this image?
The orbits
How could the radiographer modify caldwell position even more to visizalize the orbits?
Angle 30 degrees caudad with tight collimation
What is best demonstrated in this image?
The occipitobasal regoin of the skull
What changes will the radiographer make if the patient cannot get the OML perpendicular to the IR for the Townes
Angle 37 degrees caudad with IOML perpendicular to the IR
When the CR is 30 degrees caudad and the OML is perpendicular to the IR, what is visualized in the foramen magnum?
Dorsum sella+posterior cliniod process
When the CR is 37 degrees caudad and the OML is perpendicular to the IR, what is visualized in the foramen magnum?
The posterior arch of C1 within the foramen magnum
What anatomy is visualized in the petrous bones in the orbits of the ruggles view?
Internal auditory canal
What projection is this?
Lateral skull
What projection is this?
Caldwell-modified
What projection is this?
Townes skull
What are some challeges when imaging the skull on a child?
Movement, following instructions
What is best demonstrated in this view?
The base of the skull
What is best demonstrated in this view?
Facial fractures
Is this an acceptable radiograph for a facial bone study? What projection is this?
-No
-Townes facial bone
How is positioning adjusted to demonstrate the ramus?
True lateral
How is positioning adjusted to demonstrate the body of the mandible?
30 degrees roated toward the IR
How is positioning adjusted to demonstrate the symphisis menti?
45 degrees towards
How is positioning adjusted to demonstrate the general survey?
10-15 degrees towards the IR
Where will the remote TMJ be demonstrated in an open mouth view?
Inferior to the dependant mandible and more magnified
What do the axiolateral TM joints demonstrate?
Excursion of the mandible
Describe the changes in positioning from a routine Towne skull to produce this coned image of the TMJs?
-Angle 5 degrees more caudad
-Center an inch above the EAM
-Collimate to include the forhead and acanthion
What is the structure that is present in the foramen magnum on this AP axial view?
Posterior arch of C1
List the 3 skull types:
Mesocephalic, dolicoceohalic, brachiocephalic
How much would you have to rotate the MSP of the skull to align the petrous bones to be parallel to the IR for each of the skull
types?
Mesocephalic: 47 degrees
Brachiocephalic: 54 degrees
Dolicocephalic: 40 degrees
Which skull projection will place the petrous bones within the orbits?
Ruggles
Which skull projection will place the petrous bones at the infraorbital margins?
-20 degree caudad angle with the OML perpendicular
Which landmark is used to localize the TMJ?
Just anterior to the EAM
Which projection best demonstrates the size and shape of the sella turcica?
Lateral skull
Which skull projection will best demonstrate the superior orbital fissures?
Caldwell method-skull
Which sinuses are best demonstrated on the open mouth waters?
All sinuses and sphenoid through the open mouth
Which sinuses are best demonstrated on the SMV?
The sphenoid and ethmoid sinuses
Which sinuses are best demonstrated on the regular waters?
Maxillary
Which sinuses are best demonstrated on the caldwell method?
The frontal sinus and the anterior ethmoid sinus
How will the sphenoid sinuses be demonstrated in relation to the maxillary sinuses in the lateral projection?
They will be superior and posterior
Why does sinus imaging need to be erect?
To demonstrate air fluid levels
What is the relationship of the midsagittal plane to the plane of the IR in the parietoacanthial projection?
MSP perpendicular to the IR
What is the difference in angle between the glabellomeatal line and the orbitomeatal line?
8 degree difference betweeen the GML and the OML
What is the relationship of the ramus of the mandible to the plane of the IR in the Axiolateral Oblique of the mandible?
Parallel to the IR
Which projection places the CR ray perpendicular to the IOML?
All lateral projections including the axiolaterals of the TM joints
In the acanthioparietal projection, what is the main reference line utilized to position the patient?
MML to the IR
What projection must have the IOML parallel to the IR and how does one assess that it has been accomplished?
-SMV projections
-When the symphyisis menti is at the same level as the frontal bone
What structure is visualized within the foramen magnum in the skull basal view?
Odontiod process
What structure should be visualized within the foramen magnum in the skull Towne method
- Posterior clinoid process
- Dorsum sella
Which projection will best demonstrate a ‘blowout’ fracture?
Shallow/modified waters
What is the best projection to demonstrate medial or lateral fracture displacement of the ramus of the mandible?
Axiolateral ramus
In the basal view of the cranium, where are the mandibular condyles in relation to the petrous bones?
Anterior to the petrous bones
In the axiolateral projection of the TMJs, what 4 radiographs are taken?
- Left open and closed
- Right open and closed
A patient has come in for imaging of their sinuses, but has severe vertigo and is unable to stand unassisted. How will you perform the
images?
Erect, sitting
In the tangential view of the zygomatic arches, the CR is perpendicular to the OML or IOML and the top of the head is tilted 15 degrees TOWARDS or AWAY from the affected side?
- IOML
- Towards
The MML or OML is parallel to the central beam for the Water’s method.
MML
REMOTE or DEPENDENT side is demonstrated in the axiolateral projection of the TMJs
Dependent
Is the OML or the IOML used to position a Caldwell method for imaging of the sinuses?
OML(15 degrees from horizontal)
What is the CR angle for Towne skull
30 degrees
What is the CR angle for the townes mandible AP?
35
What is the CR angle for the Towne TMJ
35 degrees
What is the CR angle for the townes method of the z arches?
30 degrees
What is the error
The tip of the mandible is visualized anterior to the frontal bone
For the skull SMV
Neck too extended
What is the error
The condyles of the mandible are slightly superimposed by the petrous bones
For the skull SMV
Neck not extended enough
What is the error
There is a greater amount of anatomy visualized on the right condyle to the lateral margin of the skull
For the skull SMV
Nose is to the left
What is the error
The collimation only included the mandible
For the skull SMV
Centered too superior and not large enough feild FOV
What is the error
The orbital plates are not superimposed
For the lateral
Tilt is present
What is the error
The posterior border of the zygomatic process of the maxilla appears with bold borders
For the lateral
Rotation of the nose away from the IR
What is the error
Both tips of the posterior clinoid processes are visualized
For the lateral
Rotation of the head
What is the error
The body of the mandible is parallel to the floor
For the lateral
Chin is lifted too much
What is the error
The petrous ridges are in the center of the orbit
For the PA Axial – Caldwell
Not enough caudad angle (need another 5 degree angle)
What is the error
A greater distance on the right side from the oblique orbital line to the lateral cortices of the skull
For the PA Axial – Caldwell
Nose rotated to the left
What is the error
The MSP is such that the top of the head is toward the right of the image and the chin is slightly left
For the PA Axial – Caldwell
Vertex tilted
What is the error
The tip of the chin is over the dens
For the Parietoacanthial – Waters
Neck is over extended
What is the error
The petrous ridge is at the level of the gonions
For the Parietoacanthial – Waters
Neck too extended
What is the error
The collimation includes from the mid orbits to the dens
For the Parietoacanthial – Waters
Too small FOV collimation
What is the error
The petrous bones are in the mid to lower third of the maxillary sinuses
For the Parietoacanthial – Waters
Neck not extended enough
What is the error
The posterior arch of C1 is seen in the foramen magnum
For the AP Axial – Towne skull
Too much caudad angle
What is the error
The dorsum sellae is seen in the foramen magnum
For the AP Axial – Towne skull
Correct positioning
What is the error
The anterior clinoid processes are seen in the foramen magnum
For the AP Axial – Towne skull
Not enough caudad angle or head isn’t tilted down enough
What is the error
The petrous ridges are not symmetrical
For the AP Axial – Towne skull
Rotation of the head
What is the error
The top of the cranium is very dark
For the AP Axial – Towne skull
Windowing/filter needed
What is the error
The angle of the mandible is superimposed on the shoulder
For the Axiolateral Oblique Mandible
Too much of a cephalad (if semisupine)
What is the error
The dependent body is slightly superimposed by the remote body
For the Axiolateral Oblique Mandible
Not enough of a cephalad angle, or top of head tilted away from IR
What is the error
The remote TMJ is seen slightly superior to the dependent TMJ
For the Axiolateral TMJ
Angled cephalad instead of caudad
What is the error
The remote TMJ is seen slightly anterior to the dependent TMJ
For the Axiolateral TMJ
Nose rotated to the demonstrated side
What is the error
The posterior arch is seen in the foramen magnum
For the Modified Towne TMJ
Too much flexion or caudad angle
Label 1-9
- Outer canthus
- Infraorbital margin
- Gonion
- Glabella
- Interpupillary line
- Inner canthus
- Nasion
- Acanthion
- Mental point
Label 1&2
- Glabellometal line
- Acanthiomeatal line
Label 1-3, 6,7
1=Parietal bones
2=Lamboidal suture
3=Clivus
6=Occipital bone
7=Orbital cavities
Label 10, 14-19
10=Coronal suture
14=Posterior clinoid process
15=Mastoid process
16=Cribiform plate
17=Occipital bone
18=Mandibular rami
19=Clivus
Label 21-24
21=Dorsum sellae
22=Pterion
23=Asterion
25=Tuberculum sellae