Skull
A radiography of an AP axial Towne projection of the cranium reveals that the right petrous ridge is wider than the left side. Which specific positioning error is present on the radiograph?
Rotation of the skull is present; rotation of patient's face towards left.
A radiograph of a lateral projection of the facial bones reveals that the mandibular rami are not superimposed. What positioning error led to this radiographic outcome?
Rotation of the skull
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 shoulder be rotated 30 degrees toward the IR to prevent foreshortening of the body.
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 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 a repeat exposure?
The head and neck need to be extended more to project the petrous ridges below the ethmoid sinuses.
A radiography 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 CR angle will project the glabella into the nasal bones. CR must be parallel to the glabelloalveolar line.
A Radiograph of an SMV projection of the skull reveals that the mandibular condyles are within the petrous bone. Which specific positioning error led to this problem?
Insufficient extension of the skull, or central ray was not perpendicular to IOML.
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 a repeat exposure?
Yes, this image meets the evaluation criteria for a 30 degree PA axial projection
How much skull rotation (from the lateral skull position) toward the image receptor is required with an axiolateral oblique projection for demonstrating the body of mandible?
30 degrees
A radiograph of the waters projection reveals that the distance between the midsagittal plane and the outer orbital margins is not equal. What positioning error is present on the radiograph?
Rotation of the skull
A radiograph of the 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 a 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 open and is projected into the lower outer quadrant of the orbit.
A patient comes in to the radiology department with a possible tumor of the pituitary gland. Which radiographic projection of the cranium best demonstrates any bony involvement of the sella turcica?
Collimated; lateral projection of the sella turcica.
A true 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 image receptor.
What specific positioning error has been committed if both sides of the mandible are superimposed with an axiolateral oblique projection?
Insufficient cephalic CR angle or skull tilt
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 patients head needs to be extended more.
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 bone fracture. What radiographic routine would be best for this situation?
Parietoacanthial and R and L lateral projections.
The waters method or optional PA projections would demonstrate any possible septal deviation.
The lateral projections would demonstrate any possible fractures of the nasal bone or anterior nasal spine.
Tangential can also be used; however, is optional at most facilities.
A patient with a possible basal 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.
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? More than one correct answer is possible.
PA, PA axial, and waters
Which projection of the mandible will demonstrate the entire mandible, including the coronoid and condyloid processes?
SMV
A radiograph of the SMV projection of sinuses reveals that the distance between the mandibular condyles and lateral border of the skull is not equal. What positioning error is present on this radiograph?
Tilt of the skull
A patient with a possible blow out 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 or modified waters projection
A patient comes in to the radiology department for a skull series, but the patient cannot assume the correct position for either version of the AP axial projection because of a very short neck and severe spinal kyphosis. What can the technologist do to demonstrate the occipital bone?
Should perform the PA projection (Haas method)
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 projection?
Dense petrous pyramids super impose the orbits, obscuring facial bones structures.
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
A radiograph of a PA transoral projection reveals that the sphenoid sinus is superimposed over the upper teeth ands the nasal cavity. Hw must the position be modified to avoid this problem during the repeat exposure?
Increase extension of the neck and head to project the entire sphenoid sinus through the oral cavity.
A radiography of an AP axial Towne method projection for 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?
Overangulation of the CR or excessive flexion of the neck.