Which line should be perpendicular to the image receptor for a PA skull projection?

In extraoral radiographic examinations, both the x-ray source and the image receptor (film or electronic sensor) are placed outside the patient’s mouth. This chapter describes the most common extraoral radiographic examinations in which the source and sensor remain static. These include the lateral cephalometric projection of the sagittal or median plane; the submentovertex (SMV) projection of the transverse or horizontal plane; and the Waters, posteroanterior (PA) cephalometric, and reverse-Towne projections of the coronal or frontal plane. Panoramic radiography is described in Chapter 10, and other more complex imaging modalities are described in Chapters 11 through 14.

Which of the following articulates with the zygomatic bones?

A.  Nasal B.  Lacrimal C.  Temporal D.  Mandible

C.  Temporal
The temporal process of the zygomatic bone articulates with zygomatic process of the temporal bone to form the zygomatic arch.

An AP projection of the skull with a 30 degree caudad angle will best demonstrate which cranial bone?

A.  Frontal B.  Parietal C.  Temporal D.  Occipital

D.  Occipital

This description is better known as an AP axial (Towne) projection.

The point where the two nasal bones and the frontal bone join together is called what?

A.  Nasal septum B.  Inferior nasal conchae C.  Supraorbital groove D.  Nasion

D.  Nasion
The nasion is an anatomical landmark that corresponds with the depression at the bridge of the nose.

For a lateral (Schuller) projection of the TMJ's, how is the central ray angled?

A.  12 degrees cephalad B.  12 degrees caudad C.  25 degrees cephalad D.  25 degrees caudad

D.  25 degrees caudad

The skull is in a true lateral position. The 25 degree caudad angle prevents the two TMJ's from being superimposed.

Which of the following glands will be demonstrated if contrast media is injected into Stensen's duct?

A.  Submandibular B.  Sublingual C.  Pineal D.  Parotid

D.  Parotid
During sialography, contrast media is injected into the ducts of the salivary glands. The parotid duct (Stensen's) drains the parotid gland.

What are the names of the "L" shaped bones that are located posterior to the nasal cavity?

A.  Nasal conchae B.  Palatine C.  Maxilla D.  Zygomatic

B.  Palatine
The right and left palatine bones are "L" shaped. The vertical portion extends upward between the maxilla and the sphenoid bones. The horizontal portion makes up the posterior portion of the hard palate.

An elderly patient who has a loss of mental, physical and emotional control is said to be what?

A.  Geriatric B.  Homeostatic C.  Spastic D.  Senile

D.  Senile

Mental or physical weakness in an elderly person is a sign of senility.

What position is obtained if the head is in a lateral position and the central ray enters the zygoma?

A.  Lateral facial bones B.  Lateral paranasal sinuses C.  Lateral skull D.  Lateral mandible

A.  Lateral facial bones
For lateral facial bones the CR is centered at the level of the zygoma.

What is the opening of the external ear canal called?

A.  Auricle B.  Temporal opening C.  External auditory meatus D.  Sella turcica

C.  External auditory meatus
The external auditory meatus is part of the temporal bone.

Which of the following is the part of the skull that surrounds and protects the brain?

A.  Facial bones B.  Cranium C.  Foramen magnum D.  Cerebrum

B.  Cranium
The skull is composed of two main parts, the cranium and the facial bones.

Which position/projection would be used to best demonstrate the frontal bone?

A.  PA (Caldwell) projection B.  AP axial (Towne) projection C.  Submentovertex (full basal) projection D.  Lateral

A.  PA (Caldwell) projection
A PA (Caldwell) projection places the frontal bone on the table or upright image receptor. This puts the frontal bone as close to the image receptor as possible, which provides the best recorded detail.

What is the superior most aspect of the skull called?

A.  Floor B.  Calvarium C.  Vertex D.  Cranium

C.  Vertex
The most superior aspect of the cranium is called the vertex, as in the submentovertex (full basal) projection.

Which of the following projections are taken to demonstrate the temporomandibular joints?

A.  PA and parietoacanthial (Waters) projection B.  Open and closed mouth lateral (Law) projection C.  PA (Caldwell) and parietoacanthial (Waters) projections D.  AP and axiolateral (Mayers) projection

B.  Open and closed mouth lateral (Law) projection
Open and closed mouth axiolateral (Schuller) projections will also demonstrate the position of the condyles within the temporomandibular fossae.

The bregma in an adult would be referred to as what in an infant?

A.  Anterior fontanel B.  Posterior fontanel C.  Anterior fissure D.  Posterior sulcus

A.  Anterior fontanel
The bregma is where the sagittal suture and the coronal suture join. In an infant it is referred to as "soft spots" and is called the anterior fontanel. There are five other such areas in the skull.

For a submentovertex (full basal) projection, what line is parallel to the plane of the image receptor?

A.  Glabellomeatal line B.  Orbitomeatal line C.  Infraorbitomeatal line D.  Acanthiomeatal line

C.  Infraorbitomeatal line
The neck has to be hyperextended until the vertex of the head rests on the image receptor and the infraorbitomeatal line is parallel with the image receptor.

What is the name of the bony plate that divides the nasal cavity?

A.  Nasal ridge B.  Nasal septum C.  Nasal spine D.  Nasal bone

B.  Nasal septum
The bony nasal septum is made up of the perpendicular plate of the ethmoid bone and the vomer (facial bone).

What is the correct anatomical term describing the skull cap?

A.  Calvarium B.  Cranium C.  Vertex D.  Parietals

A.  Calvarium
The eight cranial bones are divided into the calvarium (skull cap) and the floor (base) of the cranium.

Which of the following is a disease of abnormal electrical discharges in the brain?

A.  Encephalitis B.  Epilepsy C.  Hydrocephalus D.  Meningitis

B.  Epilepsy
Abnormal brain activity involving recurrent electrical discharges describes the pathology known as epilepsy. Epileptic seizures can vary widely in severity, from mild to severe.

If the orbitomeatal line is perpendicular to the image receptor for an AP axial (Towne) projection, how much caudad angle is required?

A.  25 degrees B.  30 degrees C.  37 degrees D.  40 degrees

B.  30 degrees
It is difficult to get the orbitomeatal line perpendicular to the image receptor on most patients, therefore, put the infraorbitomeatal line perpendicular to the image receptor and use a 37 degree caudad angle.

A patient with cataracts has which of the following conditions?

A.  Opacity of the eye lens B.  Hormone deficiency C.  Constipation D.  Ulcers

A.  Opacity of the eye lens
A cataract is an eye disorder involving opacity of the lens, it is often the result of the aging process.

For a true lateral position of the skull, the midsagittal plane must be in which of these positions?

A.  Perpendicular to the image receptor B.  Parallel to the image receptor C.  At a right angle to the image receptor D.  Parallel to the central ray

B.  Parallel to the image receptor
For a true lateral position of the skull, the midsagittal plane must be parallel to the image receptor or perpendicular to the central ray in order to prevent rotation of the skull.

Which of the following is a reliable way to check for rotation on a lateral skull radiograph?

A.  Mandibular rami superimposed B.  Sella turcica visualized C.  Cranial floor superimposed D.  E.A.M. superimposed on mastoid tip

A.  Mandibular rami superimposed
Some radiographers use the superimposition of the posterior clinoid processes of the sella turcica, but since the mandibular rami are large, it is easier to see if they are superimposed.

An inflammation of the covering of the brain and/or spinal cord is called what?

A.  Meningitis B.  Cerebralitis C.  Poliomyelitis D.  Multiple sclerosis

A.  Meningitis
Meningitis is inflammation of (-itis) the meninges, the outer covering of the brain and spinal cord.

A line drawn between the lateral margin of the orbit and the E.A.M. is called what?

A.  Glabellomeatal line B.  Orbitomeatal line C.  Outer orbital line D.  External meatal line

B.  Orbitomeatal line
The orbitomeatal line (OML) is often used in skull positioning. It extends from the outer canthus of the eye (the lateral junction of the eyelids) to the external auditory meatus (E.A.M.).

What structure must be entirely in front of (anterior to) both petrous pyramids on a submentovertex (full basal) radiograph of the skull?

A.  Mandible B.  Floor of the cranium C.  Foramen magnum D.  Sella turcica

A.  Mandible
To determine the correct positioning for a submentovertex (full basal) projection, the mandibular condyles must be projected anterior to the petrous pyramids. This puts the entire mandible anterior to the petrous pyramids.

Which of the following is an injury to the brain caused by a severe impact?

A.  Concussion B.  Convulsion C.  Contusion D.  Conversion

A.  Concussion
A concussion of the brain, or cerebral concussion, is an injury that results from an impact with an object.

Which of the following projections would demonstrate the facial bones and the zygomatic arches?

A.  Parietoacanthial (Waters) projection B.  PA (Caldwell) projection C.  AP axial (Towne) projection D.  Submentovertex (full basal) projection

A.  Parietoacanthial (Waters) projection
The zygomatic arches are visible on the parietoacanthial (Waters) projection lateral to the maxillary sinuses.

What two parts of the patient's anatomy will be touching the table during a PA (Caldwell) projection?

A.  Nose and chin B.  Nose and forehead C.  Upper and lower lips D.  Cheek and chin

B.  Nose and forehead
Start by resting the patient's nose and forehead on the table. Then adjust the head until the orbitomeatal line (OML) is perpendicular to the image receptor.

What position is obtained if the head is in a lateral position and the central ray enters the lateral margin of the orbit?

A.  Lateral facial bones B.  Lateral paranasal sinuses C.  Lateral skull D.  Lateral mandible

B.  Lateral paranasal sinuses
For lateral paranasal sinuses the CR would be centered at the level of the outer canthus.

What is the name of the small gland that lies in the midline of the brain and is often calcified in the adult?

A.  Pineal B.  Pituitary C.  Thyroid D.  Parathyroid

A.  Pineal
The pineal gland is attached to the roof of the third ventricle. It secretes a variety of hormones, eg., melatonin (aids in sleeping). When the gland calcifies, older adults have difficulty sleeping.

Which of the following projections is used to demonstrate the optic foramen?

A.  Parietoacanthial (Waters) projection B.  PA (modified Waters) projection C.  Parieto-orbital oblique (Rhese) projection D.  AP axial (Towne) projection

C.  Parieto-orbital oblique (Rhese) projection
A correct Parieto-orbital (Rhese) projection will project the optic foramen in the lower outer quadrant of the orbit.

For positioning purposes, the difference between the OML and the IOML in an adult skull is approximately:

A.  3 degrees. B.  5 degrees. C.  7 degrees. D.  9 degrees.

C.  7 degrees.
This is an important fact to remember because a patient cannot always get the OML perpendicular to the IR.

Which of the following would be an alternate projection for a patient who cannot flex his/her neck sufficiently for an AP axial (Towne) projection?

A.  AP (Caldwell) projection B.  AP (Fuchs) projection C.  Axiolateral (Schuller) projection D.  PA axial (HAAS) projection

D.  PA axial (HAAS) projection
This projection results in magnification of the occipital bone, so it should only be used in the above scenario.

For an axiolateral oblique projection of the mandible, if the patient is lateral, how much is the tube angled?

A.  15 degrees cephalad B.  25 degrees cephalad C.  35 degrees cephalad D.  45 degrees cephalad

B.  25 degrees cephalad
It takes a 25 degree tube angle, or a combination of a head tilt (15 degrees) and tube angle (10 degrees) to achieve a 25 degree angle.

What is another name for the posterior angle of the mandible?

A.  Inion B.  Gonion C.  Pinna D.  Mental point

B.  Gonion
The angle (gonion) divides the mandible into anterior (body) and superior (rami) parts.

Which of the following bones helps form the base of the cranium?

A.  Sphenoid B.  Parietal C.  Occipital D.  Frontal

A.  Sphenoid
The base of the cranium is made up of the right and left temporals, the ethmoid and the sphenoid.

Which of the following is NOT one of the sutures of the cranium?

A.  Coronal B.  Squamosal C.  Lambdoidal D.  Occipital

D.  Occipital

The coronal suture is between the frontal and the parietals. The squamosal is between the parietal and temporal. The lambdoidal is between the parietals and the occipital.

The cribriform plate is a part of which of these bones?

A.  Frontal B.  Sphenoid C.  Ethmoid D.  Vomer

C.  Ethmoid
The cribriform plate has several small foramina for the passing of the olfactory nerves (the nerves of smell).

Which of the following describes involuntary contractions of voluntary muscles?

A.  Convulsions B.  Glioma C.  Hydrocephalus D.  Multiple sclerosis

A.  Convulsions
Repeated contraction and relaxation of involuntary muscles describes a convulsion.

Which of the following is NOT one of the bones that composes the calvarium?

A.  Frontal B.  Temporal C.  Occipital D.  Parietal

B.  Temporal
The calvarium (skull cap) is made up of the frontal, occipital and right and left parietals.

What is the line called between the infraorbital margin and the E.A.M. called?

A.  Infraorbitomeatal line B.  Canthomeatal line C.  Infraorbital line D.  Glabellomeatal line

A.  Infraorbitomeatal line
A line between the infraorbital margin and the external auditory meatus (E.A.M.) is called the infraorbitomeatal line.

What is it called when a patient's ventricles are filled with a large amount of cerebrospinal fluid?

A.  Meningitis B.  Epilepsy C.  Spina bifida D.  Hydrocephalus

D.  Hydrocephalus

A patient with hydrocephalus (hydro = water; cephal = brain) has an increased accumulation of cerebrospinal fluid in the ventricles, due to a problem with the normal circulation and absorption of the CSF.

The open mouth parietoacanthial (Waters) projection is used to demonstrate which of the paranasal sinuses?

A.  Frontal B.  Sphenoid C.  Maxillary D.  Ethmoid

B.  Sphenoid
The sphenoid sinuses will be projected within the open mouth.

Where will the petrous pyramids be projected in a properly positioned PA (Caldwell) projection radiograph?

A.  In the center of the orbits B.  In the upper 1/3 of the orbits C.  In the lower 1/3 of the orbits D.  In the lower 1/8 of the orbits

C.  In the lower 1/3 of the orbits
When the orbitomeatal line is perpendicular and the CR angled 15 degrees caudad, the petrous pyramids will be projected in the lower 1/3 of the orbits.

If the CR enters at a point 3/4" anterior and 3/4" superior to the E.A.M., what structure would be visualized?

A.  Petrous pyramid B.  Foramen magnum C.  Floor of the cranium D.  Sella turcica

D.  Sella turcica

The sella turcica is part of the sphenoid bone and it can be located by centering the CR (central ray) at a point 3/4" anterior and 3/4" superior to the E.A.M. (external auditory meatus).

Where should the central ray enter for a cross-table lateral, trauma skull projection?

A.  Perpendicular to the EAM B.  3/4" anterior and 3/4" superior to the EAM C.  2" superior to the EAM D.  The lateral margin of the orbit

C.  2" superior to the EAM
The same place you would center for a routine lateral skull projection.

Which of the following facial bones are paired?

1. Vomer
2. Maxilla
3. Zygoma
A.  1 only B.  2 only C.  2 & 3 only D.  1, 2 & 3

C.  2 & 3 only
All of the facial bones are paired except the vomer and the mandible.

For a parietoacanthial (Waters) projection, the patient is instructed to rest his/her head on which of the following?

A.  Nose B.  Cheek C.  Chin D.  Forehead

C.  Chin
For a parietoacanthial (Waters) projection, the only part of the patient that will be touching the table or upright image receptor will be the chin.

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

A.  Acanthion B.  Nasion C.  Glabella D.  Inner canthus

A.  Acanthion
A parietoacanthial (Waters) projection means the CR will enter the parietal area and exit the acanthion.

Which of the following is NOT a facial bone?

A.  Maxilla B.  Mandible C.  Lacrimal D.  Ethmoid

D.  Ethmoid

The ethmoid bone is one of the four cranial bones that make up the floor of the cranium.

What is the name of the membrane that separates the external auditory meatus from the middle ear?

A.  Tympanic antrum B.  Tympanic cavity C.  Tympanic membrane D.  Epitympanic recess

C.  Tympanic membrane
The tympanic membrane (ear drum) and the tympanic cavity are middle ear structures.

What is the name of the bony ridge that lies beneath the eyebrows?

A.  Glabella B.  Supercilliary ridge C.  Supraorbital groove D.  Anterior orbital protuberance

B.  Supercilliary ridge
The supercilliary ridge (arch) lies beneath the eyebrow. The glabella lies between the two supercilliary ridges.

A stroke victim may be alert but suffering from aphasia. Which of the following describes this condition?

A.  Loss of speech B.  Loss of sight C.  Loss of feeling D.  Loss of taste

A.  Loss of speech
Aphasia refers to the inability to speak (a = without; phasia = speech).

What is the name of the canal that connects the nasopharynx with the middle ear?

A.  Auditory canal B.  Internal auditory canal C.  Nasal cavity D.  Eustachian tube

D.  Eustachian tube
The eustachian tube (auditory tube) serves to equalize the pressure within the middle ear (tympanic cavity) to the atmospheric air pressure.

Which of the following bones does NOT help form the base of the orbit?

A.  Frontal B.  Maxilla C.  Zygoma D.  Nasal

D.  Nasal

The frontal, maxilla and zygoma make up the base of the orbit. The lacrimal forms the medial wall, the sphenoid and ethmoid make up most of the posterior orbit, and the palatine part of the floor.

Which of the following positions/projections will best demonstrate a "blow-out" fracture of the orbit?

A.  Lateral B.  Parietoacanthial (Waters) projection C.  PA (modified Waters) projection D.  PA (Caldwell) projection

C.  PA (modified Waters) projection
The PA (modified Waters) projection requires the head to be extended less than the parietoacanthial (Waters) projection. This will demonstrate the floor of the orbit where the fracture fragments "blow-out" into the maxillary sinus.

Which of the following is a very serious inflammation of the brain?

A.  Spinalitis B.  Encephalitis C.  Hydrocephalus D.  Meningitis

B.  Encephalitis
Inflammation of the brain, a very serious condition, is encephalitis (encephal = brain; itis = inflammation).

What structure should be projected within the shadow of the foramen magnum on a well positioned AP axial (Towne) projection radiograph of the skull?

A.  Petrous pyramids B.  Inion C.  Dorsum sellae D.  Posterior cervical arch

C.  Dorsum sellae
The dorsum sellae is the posterior portion of the sella turcica. A good AP axial (Towne) projection will project it within the foramen magnum of the occipital bone.

Which of the following topographical landmarks corresponds to the floor of the cranium?

A.  Supraorbital groove B.  Interpupillary line C.  Mental point D.  E.A.M.

A.  Supraorbital groove
The supraorbital groove lies above each eyebrow. It is an important landmark because this is where the facial bones end and the cranium begins.

The orbitomeatal line is perpendicular to the image receptor and the CR is angled 15 degrees cephalad. What projection is this?

A.  PA (Caldwell) projection B.  AP (Caldwell) projection C.  AP axial (Towne) projection D.  Submentovertex (full basal) projection

B.  AP (Caldwell) projection
Since the CR is angled 15 degrees cephalad, this must be an AP (Caldwell) projection or what is sometimes called a reverse Caldwell.

Which line should be perpendicular to the plane of the image receptor for a true lateral skull position?

A.  Infraorbitomeatal line B.  Orbitomeatal line C.  Acanthiomeatal line D.  Interpupillary line

D.  Interpupillary line
The interpupillary line must be perpendicular to the plane of the image receptor in order to prevent tilting of the skull.

What is the name of the large opening in the base of the cranium through which the spinal cord passes?

A.  Optic foramen B.  Foramen ovale C.  Foramen lacerum D.  Foramen magnum

D.  Foramen magnum

The foramen magnum is a "great hole" in the occipital bone through which the spinal cord passes.

Which of the following will best be demonstrated with a submentovertex (full basal) projection of the skull?

A.  Orbits B.  Mandible C.  Base of cranium D.  Frontal sinuses

C.  Base of cranium
The base (floor) of the cranium is made up of the right and left temporal, ethmoid and sphenoid. These bones are demonstrated on a submentovertex (full basal) radiograph.

Which of the following conditions usually results in a loss of consciousness?

A.  Convulsion B.  Contusion C.  Conflict D.  Concussion

D.  Concussion

Temporary or prolonged unconsciousness is associated with a concussion, an injury that results from an impact with an object.

For an AP 0 degree (Caldwell) projection of a trauma skull, where will the central ray enter?

A.  Acanthion B.  Glabella C.  Nasion D.  Forehead

B.  Glabella
The patient would be in a cervical collar for this projection.

The tear ducts are associated with which of the following bones?

A.  Nasal B.  Ethmoid C.  Lacrimal D.  Maxilla

C.  Lacrimal
Lacrimal means tear. The lacrimal bones are located on the medial aspect of the orbits near the tear ducts.

Why is the radiograph to the right NOT an acceptable parietoacanthial (Waters) projection?
A.  The skull is rotated B.  The orbits are magnified C.  The frontal sinuses are not visualized D.  The petrous ridges are not projected directly below the maxillary sinuses

D.  The petrous ridges are not projected directly below the maxillary sinuses
The petrous portions of the temporal bone should be projected directly below the maxillary sinuses. This radiograph is a modified Waters.

What is the name of the structure that houses the pituitary gland?

A.  Sella turcica B.  Sphenoid strut C.  Sphenoid fossa D.  Turk's fossa

A.  Sella turcica
The sella turcica protects the pituitary gland, known as the master gland of the body.

Which of the following is NOT one of the auditory ossicles?

A.  Incus B.  Stapes C.  Malleus D.  Meatus

D.  Meatus

The malleus is attached to the tympanic membrane (ear drum), it articulates with the incus which articulates with the stapes. The stapes is attached to the oval window leading to the inner ear.

Which of the following anatomical structures would NOT be found in the petrous portion of the temporal bone?

A.  Ossicles B.  Auricle C.  Cochlea D.  Tympanic cavity

B.  Auricle
The auricle or pinna is the external portion of the ear.

What is the name of the part of the temporal bone that houses the organs of hearing and equilibrium?

A.  Petrous B.  Squamous C.  Mastoid D.  Alveolar

A.  Petrous
The middle ear houses the organs of hearing and equilibrium, it is located in the petrous portion of the temporal bones.

Which of the following areas would have to be radiographed in order to demonstrate the sphenoid strut?

A.  Base of the cranium B.  Sella turcica C.  Middle ear D.  Orbit

D.  Orbit
At the apex of the orbit, next to the optic foramen is part of the sphenoid bone called the sphenoid strut.

What is the posterior portion of the sella turcica called?

A.  Sphenoid strut B.  Dorsum sellae C.  Pituitary fossa D.  Posterior clinoid

B.  Dorsum sellae
The sella turcica is a "saddle-shaped" structure that houses the pituitary gland. The dorsum sellae is the posterior portion of the "saddle".

Which of the following projections will demonstrate both zygomatic arches?

A.  Submentovertex (full basal) projection B.  Axiolateral C.  Biparietal D.  Axial oblique

A.  Submentovertex (full basal) projection
The submentovertex (full basal) projection will demonstrate the zygomatic arches projecting laterally from the zygomatic and temporal bones.

Which position/projection would be used to best demonstrate the occipital bone?

A.  PA (Caldwell) projection B.  AP axial (Towne) projection C.  Submentovertex (full basal) projection D.  Lateral

B.  AP axial (Towne) projection
An AP axial (Towne) projection places the occipital bone on the table or upright image receptor. This puts the occipital bone as close to the image receptor as possible, which provides the best recorded detail.

Which of the following bones forms the major part of the hard palate?

A.  Palatines B.  Maxillae C.  Zygomatics D.  Mandible

B.  Maxillae
It would seem logical that the palatines would form the hard palate. However, they only form the posterior 1/4. The palatine processes of the maxillae form the majority of the hard palate.

The perpendicular plate of the ethmoid bone articulates with which of the following facial bones?

A.  Maxilla B.  Zygoma C.  Vomer D.  Palatine

C.  Vomer
The perpendicular plate of the ethmoid bone articulates with the vomer of the facial bones to form the bony nasal septum.

Of the following radiographic projections, which one will show all of the paranasal sinuses?

A.  PA B.  Parietoacanthial (Waters) projection C.  Lateral D.  Submentovertex (full basal) projection

C.  Lateral
The sphenoid sinuses are the primary interest in a lateral, but the superimposed ethmoid, frontal, and maxillary are also visualized. The submentovertex (full basal) projection visualizes all but the frontal sinuses.

A radiographic examination of the nasal bones would consist of which of the following positions/projections?

A.  Parietoacanthial (Waters) projection and lateral B.  Parietoacanthial (Waters) and PA (Caldwell) projections C.  Parietoacanthial (Waters) projection and both laterals D.  Parietoacanthial (Waters) projection, AP axial (Towne) projection and lateral

C.  Parietoacanthial (Waters) projection and both laterals
Both laterals are routinely taken for comparison, with the side closest to the image receptor demonstrated best.

If the foramen magnum is NOT well visualized on an AP axial (Towne) projection radiograph of the skull, what must be done to correct it?

A.  Increase CR angle caudally B.  Decrease CR angle caudally C.  Eliminate CR angle D.  Orbitomeatal line is parallel

A.  Increase CR angle caudally
An AP axial (Towne) projection calls for the orbitomeatal line to be perpendicular and the CR angled 30 degrees caudad. If the foramen magnum is not visualized it usually means the patient cannot get the OML perpendicular, which calls for more CR angle.

Which of the following terms describes the horizontal portion of the mandible?

A.  Body B.  Ramus C.  Alveolar process D.  Condyloid process

A.  Body
The ramus would be considered the vertical portion; the condyloid process is part of the ramus. The alveolar process holds the teeth.

What is the name of the point where the two parietals articulate with the occipital bone?

A.  Bregma B.  Acanthion C.  Canthus D.  Lambda

D.  Lambda

In an infant this point would be a "soft spot" called the posterior fontanel.

For the lateral (Law) projection of the TMJ's, how much is the central ray angled and in which direction?

A.  15 degrees cephalad B.  15 degrees caudad C.  30 degrees cephalad D.  30 degrees caudad

B.  15 degrees caudad
The purpose of the 15 degree caudad angle is to project the upside TMJ below the downside TMJ so they will not be superimposed. The downside TMJ is the one of interest.

The point where the nose and the upper lip join together is called what?

A.  Acanthion B.  Nasal septum C.  Mental point D.  Alveolar process

A.  Acanthion
The acanthion is used as a positioning landmark for skull radiography.

What suture separates the two parietal bones?

A.  Coronal B.  Lambdoidal C.  Sagittal D.  Squamosal

C.  Sagittal
The sagittal suture separates the two parietal bones at the midline.

In order to demonstrate fluid in the sinuses, the patient must be radiographed in which position?

A.  Supine B.  Prone C.  Erect D.  Trendelenburg

C.  Erect
Fluid levels can be demonstrated with either an erect position or a lateral decubitus position.

What is the area between the eyebrows and above the bridge of the nose called?

A.  Supraorbital groove B.  Nasal septum C.  Glabella D.  Calvarium

C.  Glabella
For an AP axial (Towne) projection of the skull, the CR would enter at the midsagittal plane, 2 1/2" above the glabella.

A line drawn between the two pupils of the eyes defines which of the positioning lines?

A.  Interpupillary line B.  Intercanthus line C.  Biorbital line D.  Base line

A.  Interpupillary line
Inter means between. Interpupillary means between the pupils.

Which of the following is considered the master gland of the endocrine system?

A.  Pineal B.  Pituitary C.  Pancreas D.  Parotid

B.  Pituitary
The pituitary gland or hypophysis is considered the master gland of the body because it secretes a variety of hormones that control a variety of body functions.

Where is the exact location of the optic foramen?

A.  Base of the skull B.  Base of the orbit C.  Apex of the orbit D.  Posterior to the sella turcica

C.  Apex of the orbit
The orbit is "cone" shaped. The base of the orbit makes up the bony rim around the eye and the apex of the orbit is where the optic foramen is located.

What type of fracture to the floor of the orbit will result from a direct blow to the eye?

A.  Colles' fracture B.  Trimalleolar fracture C.  Blow out fracture D.  Compression fracture

C.  Blow out fracture
A direct blow to the eye (by something like a fist) results in a blow-out fracture of the orbit.

What is the flat, major part of the parietal bone called?

A.  Petrous portion B.  Squamous portion C.  Sagittal portion D.  Temporal portion

B.  Squamous portion
All the bones of the calvarium have a flat surface called the squamous portion.

To best demonstrate the floor of the cranium, which position/projection would be used?

A.  Lateral B.  AP axial (Towne) projection C.  Submentovertex (full basal) projection D.  PA (Caldwell) projection

C.  Submentovertex (full basal) projection
The submentovertex (full basal) projection demonstrates the sphenoid, ethmoid and the mastoid and petrous portions of the temporal bones.

How many salivary glands are there?

A.  2 B.  4 C.  6 D.  8

C.  6
There are right and left parotids, right and left submandibulars and right and left sublingual salivary glands.

A line between the acanthion and the external auditory meatus is known as what?

A.  Glabellomeatal line B.  Mentomeatal line C.  Alveolar line D.  Acanthiomeatal line

D.  Acanthiomeatal line

A line between the acanthion and the external auditory meatus (E.A.M.) is called the acanthiomeatal line.

The parietoacanthial (Waters) projection will best demonstrate which of the following sinuses?

A.  Frontal B.  Ethmoid C.  Sphenoid D.  Maxillary

D.  Maxillary

A good parietoacanthial (Waters) projection will project the petrous ridges directly below the maxillary sinuses.

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

Which cranial positioning line should be aligned perpendicular to the image receptor IR for a Posteroanterior PA skull radiograph?

Which positioning line is adjusted perpendicular to the plane of the image receptor when performing a PA axial Caldwell projection of the orbits?

Which of the following reference lines is placed perpendicular to the image receptor for a Parietoacanthial waters method projection?