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151 terms

Skull

STUDY
PLAY
TEA
Corresponds to the level of the Petrous Ridge
Supraorbital Groove
Corresponds to the highest level of the facial bones
Interpupillary Line
A line used in positioning to ensure that the skull is in a true lateral position
Gonion
Posterior angle of the jaw
Tragus
The small cartilaginous flap covering the EAM
Outer Canthus
Lateral junction of the eye
Orbitomeatal Line
Line between the mid-lateral orbital margin and the EAM
Glabelloaveolar Line
Line between the glabella and aveolar process of the mandible
Infraorbitomeatal Line
Line between the inferior orbital rim and the EAM
Mentomeatal Line
Line between the mental point and EAM
Glabella
Smooth, slightly raised area between the eyebrows
Inion
The most prominent point of the external occipital protuberance
Nasion
A depression at the bridge of the nose
Parietal Eminence
Distance between these two points would indicate the widest dimension of the skull
Mastoid Tip
This point can also be used in positioning fr he open-mouth C-spine
Erosion is best demonstrated on which projection?
Lateral Projection
Anatomical Landmarks used to evaluate the Lateral Projection
Orbital Lines or Roof
Rami Mandible
Body of Mandible
Anterior/Posterior Clinoids
Petrous Pyramids
Greater/Lesser Wing of Sphenoid
EAM
Mastoid Tip
Base of Skull, Mastoid Tip, Occlusal Plane
Perpendicular to the film for the AP Open Mouth C-Spine Projection
CR for routine Caldwell Projection
15 degrees Caudal
Why the sinus x-ray is erect
Air and Fluid Levels
Brachycephalic
Skull angle of 54 degrees between the midsagital plane and long axis of the petrous bone
Mesocephalic
Skull angle of 47 degrees between the midsagital plane and long axis of the pertrous bone
Mesocephalic
Average size Skull
Reids Baseline is also called
IOML or Anthropalogic Baseline
Lateral Skull Potioning, Which baseline is perpendicular to the imaginary line along the front edge ofthe IR
IOML is Perpendicular to Imaginary Line
What Projection and CR angle to demonstrate the Superior Orbital Fissure?
Caldwell, 30 degrees Caudal
Which Baseline is parallel to IR for the Submentovertex Projection (SMV)
IOML is Parallel to IR, Perpendicular to CR
CR and Angle for the Haas Method
25 degrees Cephalad
Petrous Pyramid
Densest bone of the 3 aspects of the temporal bone
Properly positioned AP Axial (Towne) projection should place the dorsum sellae in the middle of?
Foramen Magnum
Lack of symmetry of the Petrous Ridges indcates what problem with a Radiograph of an AP Axia Projection?
Rotation
What Positioning errr is present if te Mandibular Rami are not superimposed on a Lateral Skull Radiograph?
Rotation
With a traum patient, what must b determined before performing the SMV Projection?
C-Spine Injury
Where should the Petrous Ridges be located on well positioned 15 Degree Caldwell?
Lower 1/3 of the Orbit
Where should the Petrous Ridges be located on well positioned 30 Degree Caldwell?
Lower than the lower 1/3 of the Orbit
What Skull projection results in th highest Thyroid Dose
SMV (264 mR)
CR and Patient Position for the Towne Projection ofthe Skull
2 1/2" superior to the Glabella, 30 degrees Caudal to the OML
CR and Patient Position for the Lateral Skull Projection
2" Superior to the EAM, Perpendicular to the IR
CR and Patient Position for the Caldwell Projection of the Skull
PA, OML& MSP Perpendicular to the IR, 15 degrees Caudal exiting the Naison
Routine Skull Series
Towne
Lateral
Caldwell
Structures best demonstrated on the Towne Projection
Dorsum Sellae within the Foramen Magnum
Structures best demonstrated on the Lateral Projection
Sellae Turcica in Profile, Cranial halves, Orbital Plates, Clinoids ad Rami Superimposed
Structures best demonstrated on the Caldwell Projection
Petrous Pyramids in the lower 1/3 of the Orbit
Special Skull Projections
PA or AP Skull
SMV
Caldwell
Haas (Reverse Towne)
Haas (Reverse Town) Special Projection Patient Position and CR
PA, OML Perpendicular to the IR, 25 Degree Cephalad, Occipital Bone is Magnified
Caldwell Special Projection Patient Position and CR
PA, OML & MSP perpendicular to IR, 30 degrees Caudal,
Superior Orbital Fissure, Foramen Rotundum, Inferior Orbital Rim
SMV Special Projection Patient position and CR
Vertex of head on IR, IOML Parallel to IR, CR 3/4" Anterior to EAM & Perpendicular to IOML
Petrous Pyramids posterior to mandibular condyles, Sphenoid & Ethmoid Sinuses, Foramen Ovali & Foramen Spinosum
Difference in Degrees between the infraorbitomeatal & orbitomeatal lines
7-8 degrees
Small Irregular Bones occassionally found in the Sutures
Wormain
Bone that contains the Cribiform Plate
Ethmoid
Bone that contains the Foramen Ovale
Sphenoid
Bone assciated with and protects the Hypophysis Gland
Sphenoid
Cranial Bone that Articulates with all other Cranial Bones
Sphenoid
Widest portion of the cranium is formed at a level of?
Parital Tubercles
Lateral Juntion of eyelid
Outer Canthus
Posterior Angle of Jaw
Gonion
Corresponds to the highest (Nuchal) Line ofthe Occipital Bone
Inion
Located at junction of the 2 Nasal Bones & the Frontal Bone
Nasion
Line between the Midlateral Orbital Margin & the EAM
OML
Center Point of the EAM
Auricular Point
Positioning line that is primarily used for the modified Waters Projection
Lips-Meatal Line
Line used in positioning to ensure that the skull is in a true lateral position
Interpupillary line
Average KV for the Skull
Film 65-80 Kv
Digital 70-80 Kv
AP Axial (Towne) Skull results in about 10x's more dose to __________ than in a PA Axial (Haas) Projection.
Thyroid
# of Cranium Bones
8
# of Facial Bones
14
4 Cranial Bones that form the Calvaria (Skull) Cap
Frontal
Right & Left Parietal
Occipital
4 Cranial Bones that form the Floor of the Cranium
Right & Left Temporal
Sphenoid
Ethmoid
Small Horizontal Plate of the Ethmoid
Cribiform Plate
Vertical Plate of the Ethmoid Bone forming the Upper Portion of the Bony Nasal Septum
Perpendicular Plate
Structure found in the middle of the Sphenoid Bone that surrounds the Pituitary Gland
Sella Turcica
Posterior Aspect of the Sella Turcica
Dorsum Sellae
Which structure of the Sphenoid allows for the passage of the Optic Nerve & is the actual opening into th orbit
Optic Foramen
Which Structure of te Sphenoid Bone help form part of the Lateral Walls of the Nasal Cavities
Medial & Lateral Pterygoid Processes
Radiograph best demonstrates the Sella Turcica
Lateral
Aspect of Frontal Bone forms the Superior aspect of the Orbit
Orbital or Horizontal Portion
Cranial Surtures are________joints
Fiborous or Synarthrodial
Small irregular bones that sometimes develop in adult skull sutures are_________&__________bones & are most frequently found in the________suture.
Sutural & Wormian Bones, Lambdoidal Suture
Superior Rim of Orbit
SOM (Supraorbital Margin)
Notch that separates the Orbital Plates from eachother
Ethmoid Notch
Cranial Bones form the Upper Lateral Walls of the Calvarium
R & L Parietals
Cranial Bone Contains the Foramen Magnum
Occipital
Small Prominence located on Squamous Portion of the Occipital Bone
External Occipital Protuberance or Inion
3 Aspects of Temporal Bones
Squamous Portion
Mastoid Portion
Petrous Portion
Opening of Temporal Bone serves as a Passageway for nerves of Hearing & Equilibrium
Internal Acoustic Meatus
Width between 75% & 80% of Length
Mesocephalic
Width 80% or more Length
Brachycephalic
Width less than 75% of length
Dolichocephalic
CR Angles & Degree of Rotation stated for basic skull positions are based on the ___________Skull & has a angle of _________degrees between the Midsagital Plane & long axis of the Petrous Bone.
Mesocephalic, 47 degrees
Long, Narrow Skull has an angle of appx ______degrees between the midsagital plane & the long axis of the Petrous Bone
+/- 40 Degrees
Thyroid Dose for SMV projection of skull
200-300 mRad
5 Most Common Errors made during a Skull Radiograph
Rotation
Tilt
Excessive Flexion
Excessive Extension
Incorrect CR Angle
What patients require a 25% - 30% reduction in mAs during skull projections
Adults w/ Osteoporosis
Most common neuroimaging procedure performed for the cranium is done w/ what imaging modality
CT
Imaging modality used on neonates w/ a possible intracranial hemorrhage
Ultrasound
Imaging Modality performed to evaluate patients for Alzheimer disease
NuclearMedicine
Basal Skull Fracture
May produce air-fluid level in Sphenoid Sinus
Osteolytic Neoplasm
Destructive Lesion w/ irregular margins
Depressed Skull Fracture
Ping Pong Fracture
Osteoblastic Neoplasm
Proliferative bony lesion of increased density
Pituitary Adenoma
Tumor that may produce erosion of the Sella Turcica
Multiple Myeloma
Bone tumor that originates in bone marrow
Pagents Disease
Osteitis Deformans
May require increase in manual exposure factors
Which Cranial Bone is best demonstrated w/ an AP Axial (Towne Method) projection of the skull
Occipital Bone
When using a 30 degre caudad angle for AP Axial (Towne) projection of skull, what positioning line should be perpendicular to the IR
OML
Lack of Symmetry of the Petrous Ridges indicates what problem?
Rotation
If patient can't flex head for AP Axial (Towne), what should Tech do?
IOML perpendicular to IR 37 degrees Caudal
What evidence on AP Axial (Towne) indicates correct CR Angle & Correct Head Flexion
Dorsum Sellae & Posterior Clinoids visualized in Foramen Magnum
What positioning error if the Mandibular Rami are not superimposed on a Lateral Skull
Rotation
Projection where Frontal Bone has little or no distortion
PA 0 degree CR
CR for Lateral of Sella Turcica
3/4" Anterior & 3/4" Superior to EAM
Which Imaging Modality is Best to Differentiate between an Epidural & Subdural Hemorrhage
CT
Projection Best Demonstrates Sella Turcica in Profile
Lateral
Projection Best Demonstrates Foramen Rotundum in profile
25-30 degree PA Axial
Projection Best Demonstrates Clivus in profile
Lateral
Where does the CR exit for a PA Axial (Haas) of Skull
1 1/2" Superior to the Naison
CR Angle for the AP Axial (Sella Turcica) if Dorsum Sellae & Posterior Clinoid Processes are Primary Interest
37 degree Caudad
Conchae
Turbinate
Cranial Suture formed by inferior junction of the parietals to the temporal bone
Squamosal Surture
Shallow depression Posterior to Base of Dorsum Sellae & Anterior to Foramen Magnum
Clivus
Pituitary Gland
Hypophysis Cerebri
Master Gland
Suture Separates Frontal Bone from 2 Parietals
Coronal Surture
CR for AP Axial (Towne) w/ IOML Perpendicular to IR
37 Degrees Caudad to IOML
30 Degrees Caudad to OML
2 Projections show Dorsum Sellae within Foramen Magnum
AP Axial (Towne) 30 Degrees Cephalic OML
PA Axial (Haas) 25 Degrees Cephalic OML
Large Cartilanginous aspect of External Ear
Auricle or Pinna
Region where surtures join in the infant skull, soft spots
Anterior/Posterior Fontanels
Articulation @ Anterior end of Sagittal Surture
Bregma
OML
located between outer canthus & EAM
IOML
Connects infraorbital Margin to EAM
GAL
Connects Glabella to point Anterior Aspect of Alveolar process of Maxilla
GML
Line between Glabella & Eam
AML
Under Nose to EAM
LML
Lips to EAM
MML
Mental Point (Chin) to EAM
IPL
Connects Pupils or Outer Canthi of Eye
EAM
Opening of external ear canal
TEA
Superior attachment of the auricle where frames of eye glasses rest
Rotation for Lateral Skull Positioning
Rami
Clinoids
EAM
Greater Wing of Sphenoid
Petrous Pyramid
Mastoid Tip
(Left or Right Turn)
Tilt for Lateral Skull Positioning
Orbital Roof (Plate, Fontal Lines)
Body of Mandible
EAM
Lesser Wing of Sphenoid
Mastoid Tip
(Chin up or don)
Flexion/Extension
IOML Perpendicular to Imaginary Plane at Front Edge of IR
(Chin up or down)
RHESE Method Shows
Optic Foramen
3 Major Foramen Opening
ROS
Rotandum
Ovale
Spinosum
What is the best modalities used today to see the Erosion of the Sella Turcica
MRI & CT
Crista Galli
Holds Coverings of the Brain together
Junction Points
Asterion - Side
Bregma - Front
Lambda - Back
Pterion - Side
Surtures
Coronal - Front
Lambdoidal - Back
Squamosal - Side
Sagittal - Middle
Planes
MSP (Mid sagittal Plane)
Coronal
Facial Landmarks
Glabella
Naison
IPL
Acanthion
Gonion
Mental Point
Supercilliary Arch
SOG
MSP
Lateral Landmarks
TEA
Auricle (Pinna)
Tragus
Gonion (Angle)
Acanthion
Nasion
Glabella
Exam Cranial Bleed
CT
Exam to determine Brain Tissue an Brainstem
MRI