A radiograph of an AP axial proj of the crania reveals that the dorsum sellae is projected below the foramen magnum, but the anterior arch of C1 is visible w/i the foramen. WHich of the following positioning errors led to this radiographic outcome?
a. excessive CR angle
b. insufficient CR angle
c. insufficient flexion of the head and neck
d. tilt of the skull
A radiograph of a PA axial proj (Caldwell) of the cranium reveals that the petrous ridges are located at the level of the lower one third of the orbits. The tech performed this proj with the CR angled 15 degree caudal to the OML. How must positioning be altered if a repeat exposure is performed?
a. increase the extension of the skull
b. increase the flexion of the skull
c. increase the CR angle
d. none; position correct
A radiograph of a smv proj of the cranium reveals that the mandibular condyles are proj into petrous pyramids. What must be altered during teh repeat exposure to produce a more diagnostic radiograph?
a. increase extension of skull
b. increase flexion of skull
c. decrease CR angle
d. none acceptable image
A radiograph of a lateral proj of the cranium reveals that the orbital plate are not superimposed, one is slightly superior to the other. WHich of the following position error led to this outcome?
c. excessive flexion
d. excessive extension
A radiograph of a lateral cranium reveal that the mentum was cut off from the bottom of the radiograph. A 10x12 was used and it was placed crosswise. What must be altered if a repeat exposure is performed?
a. center CR at EAM
b. use 14x17
c. place cassett lengthwise
d. none; center and ir correct
A patient comes to radiology for a routine study of the cranium. He is unable to flex his head and neck sufficiently to place OML perpendicular to the IR for AP axial proj. What should the tech do to compensate for this problem w/o creating excess magnification of the occipital bone?
a. use IOML w/ CR angle of 37 degree
b. perform Haas
c. Perform smv proj
d. use AML and increase CR angle by 10 degree
Pt enters ER w possible basilar skull fracture. Which of the following skull proj would best demonstrate any blood present in the sphenoid sinus?
a. AP w/15 degree cephalic angle
b. Haas method
d. Horizontal beam lateral proj
Pt comes to radiology with a history of a possible erosion of the superior orbital fissures. Which of following prom would best demonstrate this structure?
a. PA axial w/ a 15 degree caudal angle to OML
c. PA axial w/ 25 to 30 degree caudal angle to OML
d. AP axial w/ 37 degree caudal angle to OML
Pt comes to radiology w/ possible bone cyst w/i the squamous portion of frontal bone. Which of the following proj would best demonstrate this region w/ a minimal amt of distortion of the frontal bone?
a. AP axial w/ 30 degree caudal angle to OML
b. PA axial w/ 30 degree caudal angle to OML
c. PA axial w/ 15 degree caudal angle to OML
d. PA w/ no angle to OML
Pt comes to radiology for study of the sella turcica. Which of the following routines would best demonstrate this structure?
a. PA axial w/ 15 caudal angle and lateral proj
b. AP axial and lateral proj
c. SMV and lateral proj
d. Haas and SMV
Pt comes to radiology w/ clinical history of an acoustic neuroma. Which of hte following imaging modalities will provide the best assessment for this tumor?
c. Nuclear Medicine
Pt comes to radiology w/ severe mastoiditis. WHich of the following imaging modalities will best demonstrate possible bony destruction w/i the mastoid region?
b. Nuclear Medicine
Pt comes in w clinical history of a possible pituitary adenoma. Because this is a rural hospital, CT and MRI are not available. Which radiographic proj or position would best demonstrate signs of erosion of sella turcica because of tumor?
a. AP axial Towne
b. PA Caldwell
AP axial proj w/ 30 degree caudal CR to IOML for sella turcica best visualizes what?
anterior clinoid processes
The joint found btwn lateral condylar portions of the skull and the superior articular process of C1
The classification of an average shape skull with a 47 degree angle btwn petrous pyramids and midsagittal plane
Hereditary disease which involves excessive spongy bone formation of the middle and inner ear
If pt is unable to depress chin sufficiently to bring OML perpendicular to IR the IOML can be placed perpendicular w/ CR caudad angle of _____ degrees
30 degree caudad to OML chin depressed
37 degree caudad to IOML no depression
CR 2 1/2" above glabella
MSP parallel IR, IPL perpendicular IR, IOML perpendicular edge IR
CR 2" superior to EAM
OML perpendicular IR, exit @ nasion
15 degree caudad, petrous ridge low 1/3 orbits
25-30 degree caudad, petrous ridge below orbits
PA 0 degrees
OML perpendicular IR, exit @ glabella
CR perpendicular IR (parallel to OML)
Petrous ridge fill orbits and superimpose supraorbital region
IOML parallel IR perpendicular CR
CR 1 1/2" inferior mandibular symphysis midway btwn gonion
OML perpendicular IR, 25 degree cephalad to OML
CR to MSP pass through level of EAM exit 1 1/2" sup to nasion
(can't do AP towne, magnifies occipital region but lower thyroid dosages)
Lateral: Sella Turcica
IPL perpendicular table, MSP parallel table, IOML perpendicular front IR
CR 3/4" ant 3/4" sup EAM, 4" sq collimation
AP Axial: Sella Turcica
IOML perpendicular IR
37 degree caudad if dorsum sellae and post clinoid process interest w/i foramen magnum
30 degree caudad if ant clinoid process interest above foramen magnum
CR 1 1/2" above superciliary arch exit @ foramen magnum
basal skull fractures
through dense inner structures of temporal bone, see air fluid levels in sphenoid sinus use horizontal lateral, CT
tumor of pituitary seen by CT or MRI, images show enlargement of sella turcica and erosion of dorsum sellae
paget's disease (osteitis deformans)
bony destruction then bony repair, radiographically area of lucency demonstrate destructive stages, cotton-wool appearance w/ irreg area of increase density.
Seen with nuclear medicine best
hereditary disease w/ excessive spongy bone formation of middle and inner ear, late adolescence or young adult, CT