Ch 11: Skull and Cranial Bones ~ Workbook

Which aspect of the temporal bone is considered the densest?

Petrous Portion

Which one of the auditory ossicles resembles a premolar tooth?

The Incus

Which projection of the cranium produces an image of the frontal bone with little or no distortion?

0-degree PA Skull

How long is the average external acoustic meatus (EAM)?

1 inch

Where is the CR centered for an AP Axial projection for the zygomatic arches?

1 inch above the glabella to pass through the midarches

The frontal sinuses rarely become aerated before the age of _____________.

6 years

How much skull rotation (from lateral) toward the IR is required with and axiolateral oblique projection for demonstrating each of the following? 1. body of the mandible: _______ 2. mentum region: ________ 3. ramus region: _________ 4. general survey of the mandible: ________ 5. What is if the maximum CR angle needed for all of these projections?

1. 30 2. 45 3. 0 = true lateral 4. 10-15 5. maximum CR angle for all of these projections is 25 degrees cephalad

What is the average kV range for analog skull radiography? and digital?

1. 65-85 kV 2. 75-90 kV

What are two positioning differences between the lateral projection of the cranium and the lateral projection for the facial bones?

1. IR placed lengthwise for facial bones but crosswise for the cranium 2. CR is centered to the zygoma for facial bones and 2 inches above the EAM for the cranium

The three foramina found within the orbits are what?

1. Optic foramen 2. Superior orbital fissure 3. Inferior orbital fissure

To demonstrate any possible air or fluid levels within the sinuses, it is important to:

1. Perform positions erect when possible 2. use horizontal beam

List the proper method name and the common descriptive name for the parieto-orbital oblique projection for the optic foramen

1. Rhese Method 2. Three-point landing

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

At the acanthion (at lips for PA projection)

List the 4 processes of the maxilla

1. frontal process 2. zygomatic process 3. alveolar process 4. palatine process

Give two reasons why projections of the facial bones are performed PA rather than AP when possible?

1. reduces OID 2. reduces exposure to the thyroid gland

List the five most common errors made during skull radiography

1. rotation 2. tilt 3. excessive neck flexion 4.excessive neck extension 5.incorrect CR angle

Which paranasal sinuses are demonstrated with an SMV projection of the paranasal sinuses?

1. sphenoid 2. ethmoid 3. maxillary sinuses

List 3 aspects of the temporal bones.

1. squamous 2. mastoid 3. petrous

To avoid angling the CR for the erect PA Caldwell sinus projection, the head should be adjusted to that the OML is ______-degrees from horizontal.

15 degrees

The axiolateral (Schuller method) projection for the TMJ requires a CR angle of _______ (caudad or cephalad).

25 caudad

What CR angle should be used for the PA axial (Haas method) projection for the cranium?

25 degrees cephalad

From anterior to posterior, the cone-shaped orbits project upward at an angle of __________ degrees.

30 degrees

From Anterior to posterior, the cone-shaped orbits project toward the midsagittal plane at an angle of _________ degrees.

37 degrees

There is a ______-degree difference between the orbitomeatal and glabellomeatal lines

7-8 degree

There is a _______-degree difference between the orbitomeatal and infraorbitomeatal lines

7-8 degree

Where does the CR exit for a 15-degree PA axial (Caldwell) projection for facial bones?

At the nasion

What is the name of the fracture that results from a direct blow to the orbit leading to a disruption of the inferior orbital margin?

A Blowout fracture

What device provides inherent collimation during an orthopantomographic procedure?

A narrow, vertical slit diaphragm

Which one of the following radiographic appearances pertains to an acoustic neuroma? A) Expansion of the internal acoustic canal B) Bone destruction within the middle ear C) Increased density in the sinus D) Sinus mucosal thickening

A) Expansion of the internal acoustic canal

Which of the following bones is not a facial bone? A) MIddle nasal conchae B) Lacrimal Bone C) Vomer D) Mandible

A) Middle nasal Conchae

Where does the CR exit for the PA axial (Haas method) projection of the skull? A. 1 1/2 " superior to the nasion B. 3/4" anterior to EAM C. 2 1/2" above the glabella D. Level of nasion

A. 1 1/2" superior to the nasion

What CR angle is required for the AP Axial projection of the mandible if the OML is placed perpendicular to the IR? (A) _____________ What CR angle is required for the AP axial projection of the mandible if the IOML is perpendicular to the IR? (B)___________

A. 35-degrees caudad B. 42-degrees caudad

If the area of interest is the tempomandibular fossae, angle the CR (A) _____ degrees (B) ______ to the OML for the AP axial (modified Towne) projection to reduce superimposition of the TM fossae and mastiod portions of the temporal bone.

A. 40 degrees B. caudad

Fill in the total number of bones. A. Cranium _________________ B. Facial Bones ____________________

A. 8 B. 14

Which of the following clinical indications may require an increase in manual exposure factors? A. Advanced Paget's disease B. Metastatic neoplasm C. Multiple myeloma D. Basal skull fracture

A. Advanced paget's disease

Identify the following adult Asterion with the associated Fontanels: A. Bregma B. Lambda C. Right and Left Pterion D. Right and Left Asterion

A. Anterior Fontanel B. Posterior Fontanel C. Right and Left Sphenoid D. Right and Left Mastiod

Which imaging modality is best to differentiate between an epidural and subdural hemorrhage? A. CT B. MRI C. Nuclear medicine D. PET

A. CT

The three aspects of the face that should be in contact with the head unit or tabletop when beginning positioning for the parieto-orbital oblique projection are the (A) ________, ________, and __________. The final angle between the midsagittal plane and the IR should be (B)_________ - degrees, with the (C)_________________ line to the IR. THis places the optic foramen in the (D)________ ________ quadrant of the orbit.

A. Cheek, Chin, and nose B. 53 degrees C. Acanthiomeatal D. Lower-outer

Which of the following imaging modality is the most common neuroimaging procedure performed for the cranium? A. Computed tomography (CT) B. Ultrasound C. Magnetic resonance imaging (MRI) D. Nuclear medicine

A. Computed Tomography (CT)

If the patient cannot flex the head adequately for the AP Axial (Towne Method) projection, the technologist could place the (A)________ perpendicular to the image receptor and angle the central ray (B)_________

A. IOML B. 37 degrees

Bilateral horizontal fractures of the maxillae describes a ________ fracture? A. LeFort B. Blowout C. Tripod D. Contrecoup

A. LeFort

The modified parietoacanthial (modified Waters) projection requires that the (A)______ line is perpendicular to the image receptor, which places the OML at a _______ degree angle to the tabletop

A. Lips-meatal line (LML) B. 55-degree

Which group or paranasal sinuses is best demonstrated with a Waters projection? (A)______ The OML forms a (B)________ degree angle with the IR with this projection.

A. Maxillary B. 37 degrees

The parietoacanthial (Waters) projection for the facial bones has the (A)______ ______ perpendicular to the image receptor, which places the orbitomeatal line (OML) at a (B)_______ degree angle to the tabletop and IR.

A. Mentomeatal Line (MML) B. 37-degrees

Central ray angles and degree of rotation stated for basic skull positions are based on the (A)______ (average)skull which has an approx. angle of (B)______ between the midsaggittal plane and the long axis of the petrous bone.

A. Mesocephalic B. 47

The axiolateral oblique projection for the TMJ is commonly referred to as the (A) _______ method, which requires a (B) _____ head rotation from lateral and a (C)________ caudad CR angle.

A. Modified Law B. 15 C. 15

A deviated nasal septum is most likely to occur at the junction between the (A)________ and (B)________.

A. Septal cartilage B. Vomer

Which one of the facial bone openings is formed by a cleft between the greater and lesser wings of the sphenoid bone? A. Superior Orbital Fissure B. Optic foramen C. Inferior orbital fissure D. Optical canal

A. Superior Orbital Fissure

When using a 30-degree caudad angle for the AP Axial (Towne method) projection of the skull, which positioning line should be perpendicular to the image receptor? A. OML B. IOML C. GAL D. AML

A. The Orbitomeatal line (OML)

List the 4 most commonly performed routine projections for paranasal sinuses:

A. lateral B. PA Caldwell C. paritoacanthial (Waters) D. SMV

SITUATION: As part of a study the zygomatic arches, the technologist attempts to perform the SMV position. Because of the size of the patient's shoulders, he is unable to flex his neck adequately to place the IOML parallel to the image receptor. What other options does the technologist have to produce an acceptable SMV projection

Angle CR to place it perpendicular to IOML. Angle IR to maintain a perpendicular relationship between CR and IR. This will prevent distorting any anatomy.

What is the older term for the maxillary sinuses?

Antrum of Highmore

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

At the Acanthion

Which projection of the mandible projects the opposite half of the mandible away from the side of interest?

Axiolateral Oblique projection

What CR angle must be used to project the petrous ridges just below the orbital floor with the PA axial projection (Caldwell method)? A. None, CR is perpendicular B. 30 degrees C. 20 degrees D. 45 degrees

B. 30 degrees

Which of the following imaging modalities best demonstrates otosclerosis? A. Nuclear Medicine B. CT C. Conventional Radiography D. Sonography

B. CT

Which skull positioning line is placed parallel to the plane of the IR for the SMV projection? A. OML B. IOML C. AML D. GAL

B. Infraorbitomeatal line (IOML)

The drainage pathway for the paranasal sinuses is called the what? A. Uncinate process B. Ostiomeatal complex C. Paranasal sinus D. Lateral masses

B. Ostiomeatal complex

Which position is most often used when performing a CT study of the sinuses? A. Supine B. Prone C. Erect D. Supine with 20 degree oblique of skull from AP position

B. Prone

Which specific positioning error is present if the mandibular rami are not superimposed on a lateral skull radiograph? A. Tilt B. Rotation C. Overflexion of head and neck D. Incorrect central ray angle

B. Rotation

Which projection/ method of the TMJ requires that the skull be kept in a true lateral? A. Modified Law B. Schullers C. Axiolateral D. Modified Towne

B. Schuller

What is another term for the second cranial nerve? A. Olfactory nerve B. The Optic nerve C. Maxillary nerve D. Trigeminal nerve

B. The Optic Nerve

Which imaging modality is commonly performed on neonates with a possible intracranial hemorrhage? A. Computed tomography (CT) B. Ultrasound C. Magnetic resonance imaging (MRI) D. Nuclear medicine

B. Ultrasound

Which two sensory functions occur within the inner ear?

Balance (equilibrium) and Hearing

Identify the following clinical indication: Fracture that may produce an air-fluid level in the sphenoid sinus

Basal skull fracture

Identify the correct mandibular term to the following definition or description: Horizontal portion of the mandible.

Body

This skull size classification has a width greater than 80% of its length:

Brachycephalic

Identify the four asterions:

Bregma Lambda Right and Left Pterion Right and Left Asterion

Which one of the following projections best demonstrates the foramen rotundum? A. SMV B. 25-30 degrees AP axial C. 25-30 degrees PA axial D. Lateral

C. 25-30 degrees PA axial

Which one of the following projections best demonstrates the clivus in profile? A. AP axial B. 13 degrees PA C. Lateral D. SMV

C. Lateral

A properly positioned AP Axial (Town Method) projection should place the dorsum sellae into the middle aspect of what structure? A. Orbits B. Clivus C. Foramen magnum D. Anterior arch of C1

C. The Foramen Magnum

Where is the CR centered for a lateral position for the facial bones? A. Outer canthus B. Acanthion C. Zygoma D.Nasion

C. Zygoma

Situation: A patient comes to the radiology department with a possible tumor of the pituitary gland. Which radiographic projection of the skull best demonstrates this fracture?

Collimated, Lateral projection of the sella turcica

Identify the correct mandibular term to the following definition or description: Posterior process of upper ramus.

Condyloid process

Which aspect of the Which aspect of the mandible is best visualized with an AP axial projection?

Condyloid process

Identify the correct mandibular term to the following definition or description: Bony process located anterior to mandibular notch.

Coronoid process

The small horizontal plate of the ethmoid bone is called:

Cribiform plate

What type of image receptor must be used with analog orthopantomography?

Curved, non-grid cassette

TRUE/FALSE: Secondary osteomyelitis is often caused by a tumor invasion

False

Which of the following bones does not articulate with the zygomatic bone? A) Temporal bone B) Maxilla C) Frontal Bone D) Sphenoid

D) Sphenoid

Which one of the following projection best demonstrates the sella turcica in profile? A. AP axial B. SMV C. 15 degree PA axial D.Lateral

D. Lateral Skull

Which of the following imaging modality is most commonly performed to evaluate patients for Alzheimer's disease? A. Computed tomography (CT) B. Ultrasound C. Magnetic resonance imaging (MRI) D. Nuclear medicine

D. Nuclear Medicine

A lack of symmetry of the petrous ridges indicates which of the following problems with a radiograph of an AP axial projection? A. Tilt B. Central ray angle C. Flexion or extension D. Rotation

D. Rotation

Identify the following clinical indication: Also called a "ping-pong" fracture

Depressed skull fracture

This skull size classification has a width less than 75% of the length:

Dolichocephalic

The posterior aspect of the sella turcica is called the:

Dorsum sellae

Situation: A patient with a clinical history of acoustic neuroma comes to the radiology department. Which imaging modality or modalities can be performed for this type of pathology?

Either MRI or CT can be performed

Which specific positioning error is present if the petrous ridges are projected higher in the orbits than expected for a 15-degree PA Axial projection?

Either the head is too flexed or the CR angle is insufficient

Which structure allows for communication between the nasopharynx and the middle ear?

Eustachian Tube

A radiograph of a 15-degree PA axial (Caldwell) projection of the cranium demonstrates that the petrous ridges are projected at the inferior orbital margin. Which positioning error(s) led to this radiographic outcome?

Excessive extension or excessive caudad central ray angle; Projects the petrous ridges lower than expected (should be in lower 1/3 of the orbit)

SITUATION: A radiograph of a superoinferior projection of the nasal bones reveals that the glabella are superimposed over the nasal bones. What positioning error led to this radiographic outcome, and how can it be corrected during the repeat exposure

Excessive flexion of the head and neck or incorrect C R angle will project the glabella into the nasal bones. The C R must be parallel to the GAL line

What must be done to prevent the ramus of the mandible from being superimposed over the cervical spine with an axiolateral oblique projection of the mandible?

Extend the chin

TRUE/FALSE The mastoid portion of the temporal bone is the desest of the 3 aspects of the temporal bone?

FALSE petrous portion

True/False: An increase in KV of 25%-30% (using manual techniques) is often required for the geriatric patient with advanced osteoporosis.

False

TRUE/FALSE Two older terms for the orbitomeatal line OML are Reid's base line and the anthropologic base line .

False these are other terms for the infraorbitomeatal line

True or False: MRI is an excellent imaging modality for the detection of small metal foreign bodies in the eye.

False ~ Oh, the horror!

True/False: The older term for the orbitomeatal line (OML) are Reid's base line and the anthropologic base line.

False: These terms refer to the IOML

TRUE/FALSE Facial bone studies should always be performed recumbent whenever possible

False; Best to perform with patient erect

True/False: The CR should be angled 20-25 degrees caudad for the PA axial projection of the mandible

False; Cephalad

True or False: Nuclear medicine is not helpful in diagnosing occult facial bone fractures.

False; Nuc Med is used for this

True/False: The tangential projection for a unilateral zygomatic arch requires that the skull be rotated and tilted 15-degrees away from the affected side

False; Toward the affected side

True or false: The majority of the nose is formed by the right and left nasal bones

False; (most of the nose is made uo of cartilage)

Cranial sutures are classified as being what type of joints?

Fibrous and synarthrodial

Which one of the maxillary processes is considered most superior?

Frontal Process

Which paranasal sinuses are best demonstrated with a PA (Caldwell) projection?

Frontal and anterior ethmoid

List the four cranial bones that form the calvaria (skull cap).

Frontal bone, occipital bone, left parietal bone, right parietal bone

For the superoinferior projection of the nasal bones, the image receptor is placed perpendicular to what line?

Glabelloalveolar line (GAL)

Identify the correct mandibular term to the following definition or description: Mandibular angle

Gonion

SITUATION: A radiograph of a PA Caldwell projection for sinuses reveals that the petrous ridges are projected into the lower half of the orbits and are obscuring the ethmoid sinuses. The technologist used a horizontal x-ray beam for the projection. The skull was positioned to place the OML at a 15 degree angle from the horizontal plane. What positioning modification is needed to correct this problem during the repeat exposure?

Head and neck need to be extended more to projection the petrous ridges below the ethmoid sinuses

Situtation: A patient with a possible basal skull fracture enters the emergency room. No CT scanner is available. Which specific position may provide radiographic evidence of this fracture?

Horizontal beam (dorsal decubitus) lateral position - will demonstrate a possible air-fluid level in the sphenoid sinus

If the patient cannot stand for the lateral projection of the paranasal sinuses, it should be taken with?

Horizontal x-ray beam

SITUATION: A radiograph of a PA transoral projection reveals that the sphenoid sinus is superimposed over the upper teeth and the nasal cavity. How must the position be modified to avoid this problem during the repeat exposure

Increase extension of the head and neck to project entire spehnoid sinus through oral cavity

Which facial bone opening has the maxillary branch of the 5th cranial nerve passing through it?

Inferior orbital fissure

What specific positioning error has been committed if both sides of the mandible are superimposed with an axiolateral oblique projection?

Insufficient cephalic angle or not enough skull tilt

A radiograph of an SMV projection of the skull reveals that the mandibular condyles are within the petrous bone. What specific positioning error led to this problem?

Insufficient extension of the skull, or CR was not perpendicular to the IOML

SITUATION: A radiograph of an axiolateral oblique projection of the mandible reveals that the body of the mandible is severely foreshortened. The body of the mandible is the area of interest. What positioning error led to this radiographic outcome?

Insufficient rotation of the skull toward the IR. The skull should be rotated 30 degree (from lateral position) toward the IR to prevent foreshortening of the body

Where are the petrous ridges located on a well-positioned parietoacanthial projection?

Just below the maxillary sinuses

What suture runs between the occipital bone and the parietal bones?

Lambdoidal suture

Identify the sinus projection used to best visualize: All 4 paranasal sinuses demonstrated:

Lateral

Which single projection for a paranasal sinus routine provides an image of all 4 sinus groups?

Lateral

This projection best gives a profile image of the nasal bones and nasal septum

Lateral Nasal Bones

Which radiographic projection best demonstrates the sella turcica and dorsum sellae?

Lateral Skull

Where should the CR exit for both PA Waters and PA transoral (open-mouth Waters) projection?

Level of the acanthion

Identify the correct mandibular term to the following definition or description: U-shaped notch

Mandibular notch

What is the largest immovable bone of the face?

Maxilla

Which structures of the sphenoid bone help form part of the lateral walls of the nasal cavities?

Medial and Lateral Pterygoid processes

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

Mentomeatal Line (MML)

Identify the correct mandibular term to the following definition or description: The chin

Mentum

This skull size classification has a width between 75% and 80% of the length:

Mesocephalic

Aligning the ___________ plane perpendicular to the IR prevents rotation of either a PA or AP axial mandible.

Midsagittal

This projection best visualizes this floor of the orbits (or blowout fractures).

Modified Waters method

SITUATION: A patient with a possible blowout fracture of the right orbit enters the emergency room. In addition to the basic facial bone routine, what single projection would best demonstrate this type of injury?

Modified parietoacanthial (modified waters)

Identify the following clinical indication: Bone tumor that originates in the bone marrow

Multiple myeloma

The purpose of the _________ or ____________, is to divide the nasal cavity into compartments and circulate air coming into the nasal cavities.

Nasal conchae or Turbinates

A radiograph of an AP axial (Towne method) projection for the cranium reveals that the mid to lower mandible is cut off and not demonstrated. What should the technologist do?

No repeat exposure is necessary. Because of elongation of the facial mass in the AP axial projection for the skull, cutting off aspects of the mandible is acceptable

SITUATION: A radiograph of a parietoacanthial Waters projection reveals that 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 exposure?

No, the petrous ridges should be projected just below the maxillary sinuses. The patient's head needs to be extended more.

SITUATION: A radiograph of a parieto-orbital oblique Rhese projection reveals that 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 problem during the repeat exposure

No. Increase extension of the head and neck The AML should be placed perpendicular to the IR to ensure that the optic foramen is now open. and is projected into lower quadrant of the orbits

SITUATION: A radiograph of a parietoacanthial projection Waters reveals that the petrous ridges are projected just below the maxillary sinuses. What positioning error (if any) are present

None. The petrous ridges should be below the floors of the maxillary sinuses on a well-positioned parietoacanthial

Identify the positioning line for the given cranial landmark: A line between the midlateral orbital margin and the EAM

OML

This projection best visualizes a single zygomatic arch

Oblique inferosuperior projection

Which cranial positioning line is placed perpendicular to the image receptor for a PA or PA axial projection of the mandible?

Orbitomeatal Line (OML)

Which imaging system provides a single, frontal perspective of the entire mandible?

Orthopantomography, or panoramic tomography

Identify the following clinical indication: Proliferative bony lesion of increased density

Osteoblastic neoplasm

Identify the following clinical indication: Destructive lesion with irregular margins

Osteolytic neoplasm

A radiograph of an AP axial (Towne method) projection for the cranium reveals that the posterior arch of C1 is projected within the foramen magnum. The dorsum sellae is superimposed on the posterior arch as well. What is the positioning error(s)?

Overangulation of the CR or excessive flexion of the neck

Identify the sinus projection used to best visualize: frontal and ethmoid sinuses:

PA Caldwell

Identify the sinus projection used to best visualize: Sphenoid sinus in oral cavity:

PA transoral

SITUATION: A patient comes to the radiology department with a clinical history of a deviated bony nasal septum. Which facial bone projections best demonstrate the degree of deviation.

PA, PA Axial, and Waters will demonstrate a possible bony nasal septal deviation

Identify the following clinical indication: Also known as osteitis deformans

Paget's disease

This projection best visualizes the optic foramen

Parieto-orbital Oblique (Rhese Method) projetion

Identify the sinus projection used to best visualize: the maxillary sinuses:

Parietoacanthial

SITUATION: A patient with a possible fracture of the nasal bones enters the emergency room. The physician is concerned about deviation of the bony nasal septum along with possible nasal bones fracture. What radiographic routine would be best for this situation

Parietoacanthial and right and left lateral projections. The parietoacanthial Waters or optional PA axial would demonstrate any possible septal deviation. The lateral projection would demonstrate any possible fracture of nasal bones or anterior nasal spine. The superoinferior tangential projection would provide an axial perspective but is considered an optional projection in most departments and not part of the routine.

Situation: A patient comes to the radiology department for a skull series, but the patient cannot assume the correct position for either version of the AP axial (Towne method) projections because of a very short neck and severe spinal kyphosis. What can the technologist do to demonstrate the occipital bone?

Perform the PA axial (Haas method) projection

SITUATION: A patient with a possible fracture of the left zygomatic arch enters the emergency room. 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 projections can the technologist provide to better define this area?

Perform the oblique inferosuperior tangential projection. These are ideal to demonstrate a depressed fracture of zygomatic arch. Bilateral projections are generally taken for comparison.

The vertical plate of the ethmoid bone forming the upper portion of the bony nasal septum is the what?

Perpendicular plate

Identify the following clinical indication: Tumor that may produce erosion of the sella turcica

Pituitary adenoma

Identify the correct mandibular term to the following definition or description: The vertical portion of mandible.

Ramus

Situation: A possible linear fracture of the right parietal bone enters the emergency room. Which single radiographic projection of the skull best demonstrates this fracture?

Right Lateral projection of the skull

What are the two most common errors radiographers make when imaging the skull?

Rotation and Tilt

A radiograph of a 15-degree PA axial (Caldwell) projection demonstrates that the distance between the right mid-lateral orbital borders and the lateral margin of the skull cortex is greater than the left side. Which positioning error led to this radiographic outcome?

Rotation of the patient's face (skull) to the left

SITUATION: A radiograph of a lateral projection of the facial bones reveals that the mandibular rami are not superimposed. What positioning error led to this radiograph outcome

Rotation of the skull

SITUATION: A radiograph of a parietoacanthial Waters projection reveals that the distance between the lateral margins of the orbits and the lateral aspect of the cranial cortex is not equal. What type of positioning error led to this radiographic outcome?

Rotation of the skull

A radiograph of an AP axial (Towne method) projection of the cranium reveals that the right petrous ridge is wider than the left side. Which specific positioning error is present on this radiograph?

Rotation of the skull is present; rotation of the patient's face toward the left

With a possible trauma patient, what must be determined before performing the SMV projection of the skull?

Rule out any cervical fractures or subluxation

Identify the sinus projection used to best visualize: Inferiosuperior view of sphenoid and ethmoid sinus

SMV

Which projection of the mandible will demonstrate the entire mandible, including the coronoid and condyloid processes?

SMV projection

This suture is located between the parietal bones, running from the frontal to occipital bones

Sagittal suture

A structure found in the middle of the sphenoid bone that surrounds the pituitary gland is the:

Sella Turcica

A radiograph of a lateral projection of the skull reveals that the orbital plates are not superimposed. One orbital plate is slightly superior to the other. Which specific positioning error led to this radiographic outcome?

Skull Tilt

Which sinus is projected through the open mouth with a PA axial transoral projection?

Sphenoid Sinus

List the four cranial bones that form the floor of the cranium

Sphenoid bone, occipital bone, left temporal bone, right temporal bone

Which sinuses are projected through the oral cavity with the PA axial transoral projection?

Sphenoid sinus

What suture runs between the parietal bones and the temporal and sphenoid bones?

Squamous Suture

This projection best visualizes the bilateral zygomatic arches

Submentovertex (SMV) projection

Identify the correct mandibular term to the following definition or description: The point of union between both halves of the mandible.

Symphysis menti

Identify the positioning line for the given cranial landmark: Corresponds to the level of the petrous ridge

TEA

What is the name of the thin plate of bone that separates the mastoid air cells from the brain?

Tegmen Tympani

An AP axial (Towne method) radiograph for the cranium demonstrates the dorsum sellae projected above or superior to the foramen magnum. The foramen magnum is distorted. Which positioning error(s) occurred?

The CR was angled less than 37-degrees to the IOML, or less than 30-degrees to the OML (could be caused by a 30-degree angle to the IOML). This error can be addressed with more flexion of the neck, as well.

What is the name of the passageway between the maxillary sinuses and the middle nasal meatus?

The Infundibulum

Which cranial bone is best demonstrated with an AP Axial (Towne method) projection of the skull?

The Occipital Bone

Which structure of the sphenoid bone allows for the passage of the optic nerve and is the actual opening into the orbit?

The Optic Foramen

Which structures specifically are visualized better on the modified parietoacanthial projection as compared with the basic waters projection?

The Orbital Floors and Rims

Which aspect of the frontal bone forms the superior aspect of the orbit?

The Orbital or horizontal Portions

Which facial bone structures are best seen with a parietoacanthial projection?

The Orbits, including infraorbital rims, bony nasal septum, maxillae, and zygomatic bones & arches

SITUATION: A patient comes to the radiology department to rule out a possible polyp within the sphenoid sinus. What routine and/or special projection provides the best overall assessment of the sinuses for this patient

The PA transoral special projections in addition to the routine four sinuses projection ~ 1. Lateral 2. PA Caldwell 3. Waters 4. SMV

Which structure serves as an opening between the mastoid portion of the temporal bone and the middle ear?

The aditus

What suture runs between the frontal bone and occipital bones?

The coronal suture

What is the major disadvantage of performing a straight PA projection for facial bones, with no CR angulation or neck extension, as compared with other PA facial bone projections?

The dense Petrous Pyramids superimposing the orbits, obscurring facial bones

What evidence on an AP axial (Towne method) radiograph indicates whether the correct CR angle and correct head flexion were used?

The dorsum sellae and posterior clinoids should be projected into the foramen magnum

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

The glabella

SITUATION: A lateral radiograph of the facial bones demonstrates that 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 exposure

The head was tilted. Ensure that the MSP is parallel to the IR

Which cranial line is placed parallel to the floor for orthopantomography of the mandible?

The infraorbitomeatal line (IOML)

Where will the petrous ridges be projected with a 15-degree PA axial (Caldwell) projection of the cranium?

The lower third of the orbits

Which one of the auditory ossicles picks up sound vibrations from the tympanic membrane?

The malleus

An infection of the teeth may travel upward and involve which sinus?

The maxillary sinus

SITUATION: 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. Which single projection demonstrates any possible air-fluid levels in the sinuses

The most diagnostic projection is the horizontal beam lateral projection to demonstrate any air-fluid levels

What is the one major difference in positioning between the parietoacanthial and PA axial transoral projections?

The mouth (oral cavity) is open with the PA transoral projection

What is the name of the small membrane that connects the middle to the inner ear?

The oval or Vestibular window

A lateral skull radiograph demonstrates one mandibular ramus about 0.5cm more anterior than the other. Which positioning error occurred?

The skull is rotated

The small section of bone separating the optic foramen and the superior orbital fissure is called what?

The sphenoid strut

Which one of the auditory ossicles is considered to be the smallest?

The stapes

What is the major function of the Eustachian tube?

To allow for equilization of air pressure

TRUE/FALSE Most CT studies of the sinuses do not require the use of contrast media?

True

TRUE/FALSE The common basic PA axial projection for facial bones requires a 15 degree caudad angle of the central ray, which projects the dense petrous ridges into the lower one-third of the orbits

True

TRUE/FALSE: MRI is the preferred modality to study soft tissue changes and masses within the sinus

True

TRUE/FALSE: The mandibular condyles move anteriorly as the mouth is open.

True

TRUE/FALSE: The modified law method provides a bilateral and functional study of the TMJ.

True

TRUE/FALSE: Ultrasound exams of the maxillary sinuses to rule out sinusitis are possible.

True

True or false: The PA axial projection of the mandible produces an elongated view of the condyloid processes.

True

True/False: Both oblique inferosuperior (tangential) projections for the zygomatic arch are generally taken for comparison

True

True/False: CT is ideal for facial bone studies because it allows for visualization of bony structures as well as related soft tissues of the facial bones

True

True/False: Fo ra true PA projection of the mandibular body, the AML should be perpendicular to the image receptor

True

True/False: Lateral projections for nasal bones generally are taken bilaterally for comparison.

True

Where is the central ray centered for a lateral projection of the skull?

Two inches above the External Acoustic Meatus (EAM)

Situation: A neonate has a clinical history of craniosynostosis. Because of the age of the patient, the physician does not order a radiographic procedure of the cranium. What other imaging modality can be performed to evaluate the patient for this condition?

Ultrasound

What is the proper method name for the parietoacanthial projection of the facial bones?

Waters method

Small, irregular bones that sometimes develop in adult skull sutures are called _________ or __________ bones and are most frequently found in the ________________ suture?

Wormian Sutural Lambdoidal

SITUATION: A radiograph of a 30 degree PA axial projection of the facial bones reveals that 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 done to improve the quality of the image during the repeat exposure

Yes, this image meets the evaluation criteria for a 30 degree PA axial projection

Which specific facial bone structures (other than the mandible) are best demonstrated with the submentovertex (SMV) projection if the correct exposure factors are used (soft tissue technique)?

Zygomatic Arches

What analog kV range should be used for sinus radiography? (a) _____ Digital kV range? (b) ______

a. analog: 65- 80 b. digital: 75- 85

Which soft tissue landmark is found at the base of the anterior nasal spine?

acanthion

Benign tumor of the auditory nerve sheath

acoustic neuroma

What is the collective term for the small bones in the middle ear?

auditory ossicles

Which structure makes up the cartilaginous external ear?

auricle or pinna

Identify the positioning line for the given cranial landmark: The center point of the EAM

auricular point

Specifically, where are the frontal sinuses located?

between inner and outer tables of the skull posterior to glabella

Benign, cystlike mass or tumor of the middle ear

cholesteatoma

What is the name of the notch that separates the orbital plates from each other?

ethmoidal notch

A small prominence located on the squamous portion of the occipital bone is called the?

external occipital protuberance or inion

Which 2 cranial bones articulate with the maxilla?

frontal and ethmoid bones

Identify the positioning line for the given cranial landmark: A smooth, slightly depressed area between the eyebrows

glabella

Identify the positioning line for the given cranial landmark: A line between the glabella and alveolar process of the maxilla

glabelloalveolar line

Identify the positioning line for the given cranial landmark: Posterior angle of the jaw

gonion

Which facial bones from the posterior aspect of the hard palate?

horizontal portion of the palatine bones

Identify the positioning line for the given cranial landmark: A line between the infraorbital margin and EAM

infraorbitomeatal line IOML

Identify the positioning line for the given cranial landmark: Corresponds to the highest "nuchal" line of the occipital bone

inion

Which opening in the temporal bone serves as a passageway for nerves of hearing and equilibrium?

internal acoustic meatus

Identify the positioning line for the given cranial landmark: A line used in positioning to ensure that the skull is in the true lateral position

interpupillary line

Which facial bone is associated with the tear ducts?

lacrimal bones

Which specific aspect of the ethmoid bone contains the ethmoid sinuses?

lateral masses or labryinths

Identify the positioning line for the given cranial landmark: A positioning line that is primarily used for the modified Waters projection

lips-meatal line

Bacterial infection of the mastoid process

mastoiditis

Identify the positioning line for the given cranial landmark: A line between the mental point and EAM

mentomeatal line

Identify the positioning line for the given cranial landmark: Located at the junction of the 2 nasal bones and the frontal bone

nasion

New and abnormal growth

neoplasia

Which cranial bone contains the foramen magnum?

occipital

What is the name of the oval processes found on the occipital bone that helps form the occipitoatlantal joint?

occipital condyles or lateral condylar portions

Hereditary disease involving excessive bone formation of middle and inner ear

otosclerosis

Identify the positioning line for the given cranial landmark: Lateral junction of the eyelid

outer canthus

This projection best visualizes the inferior orbital rim, maxillae, nasal septum, nasal spine, zygomatic bone and arches

parietoacanthial Projection

The long, narrow-shaped skull has an angle of approximately how much between the midsagittal plane and the long axis of the petrous bone?

plus-or-minus 40 degrees

Growth arising from mucous membrane

polyp

Which cranial bones from the upper lateral walls of the calvarium?

right and left parietals

SITUATION: A radiograph of a parietoacanthial projection reveals that the distance between the midsagittal plane and the outer orbital margin is not equal. What positioning error is present on this radiograph

rotation of the skull

What is the name of the small membrane that will move outward to transmit impulses to the auditory nerve, thus creating the sense of hearing?

round or cochlear window

Identify the positioning line for the given cranial landmark: Corresponds to the highest level of the facial bone mass

supraorbital groove

Which term describes the superior rim of the orbit?

supraorbital margin (SOM)

SITUATION: A radiograph of an SMV projection for sinuses reveals that the distance between the mandibular condyles and lateral border of the skull is not equal. What specific positioning error is present on this radiograph

tilt of the skull

What positioning error has been committed if the EAMs are not superimposed with one of them more superior than the other on a lateral projection of the cranium?

tilt of the skull

Which external landmark corresponds with the level of the petrous ridge?

top of the ear attachment (TEA)

Identify the positioning line for the given cranial landmark: The small cartilaginous flap covering the ear opening

tragus

A free floating zygomatic bone is the frequent result of a _____fracture.

tripod

Which small membrane marks the beginning of the middle ear?

tympanic membrane (eardrum)

Which facial bones are sometimes called the "cheek bones"?

zygomatic or malar bones