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2014-10-26 11:01:23

Show Answers:

  1. What is the routine for a cranium series
    what are the special routines for a cranium series
    • ap axial towne
    • lateral
    • PA 15 deg (caldwell) PA 25 deg or PA 0 deg

    • PA axial (haas)
    • SMV (submentovertex)
  2. where is the cr for an ap axial (towne) method
    how much is cr angle for both areas
    • CR is 2.5 in above glabella
    • CR 30 deg caudad to OML or 37 deg caudad to IOML
  3. what lateral is required for a lateral skull
    where is the cr for a lateral skull
    • right lateral
    • CR 2 in superior to EAM
  4. In a rt lateral skull the MSP is parallel to what and the _____ is perpendicular to ______
    • xray table
    • interpupillary line
    • table
  5. When positioning and xraying the skull
    what is the minimum SID and kv range
    what size focal spot
    • 40''
    • 75-90 kv
    • small FSS
  6. in the ap towne axial method what must we ask the patient to do in order to get OML to perpendicular to the table
    when a patient is unable to get the OML perp to the table what must you do instead
    • depress the chin
    • you must angle the tube 37 deg caudad  and get the IOML perpendicular to the table and you can use a sponge if needed
  7. what is the differences of degrees between the OML and the IOML
    7-8 deg difference
  8. what structures are visualized in the ap axial towne view

    occipital bone petrous pyramids and foramen magnum are demonstrated with the dorsum sellae and posterior clinoids visualized in foramen magnum
  9. what position is used to demonstrate air fluid levels in the sphenoid sinus which is a sign of a basal skull fx if intracranial bleeding occurs
    cross table lateral
  10. what is the position of the body in a right lateral skull position
    what line must we align perpendicular to the table
    Certain patients with broader shape may require what to get this position
    • semi supine (or slight rao)
    • interpupillary line
    • a sponge to keep the head up
  11. where is the cr  exiting for a pa axial (caldwell) and what is the angulation of tube
    Where does CR exit?
    What line must be perp in this projection
    what instructions will give the patient to acquire this position
    • CR 15 deg caudad and centered to exit at the nasion
    • OML
    • tuck the chin towards your chest
  12. what is the alternative method to the pa axial caldwell projection to allow better visualization of the superior orbital
    where do u center
    Where is the CR exiting
    • pa axial with a 25-30 deg caudad angle
    • center in same area so CR exits at the nasion and the OML is perp to the table
  13. the pa axial caldwell 25-30 caldwell method where are the petrous ridges
    petrous pyramids are projected at or below the IOM to allow visualization of the entire orbital margin
  14. In the pa projection 0 degree where is the CR and is parallel to what?
    where is it exiting and what is position of the patient
    which line is perp to the table
    • CR is perp to IR and parallel to OML and is centered to exit at the glabella
    • the pt is face down with the chin tucked towrds chest
    • OML
  15. before doing and SMV projection special routing of the skull what must you rule out first
    cervical spine fx or subluxation on trauma patients when attempting this position
  16. where is the CR in an SMV projection
    CR is perp to IOML and 1.5 inch below mandibular symphysis or midway between the gonions
  17. Which line must be perp to the CR when doing the SMV
    How do we achieve this position with the patient
    • IOML
    • ask patient raise the chin hyperextend the neck if possible until line is per to CR
  18. Is the 10x12 cassette lengthwise or crosswise for an ap axial towne method
    Which position of the skull requires the IR to be crosswise
    • lengthwise
    • right or left lateral skull
  19. what position of the skull shows the petrous ridges over the lower 1/3 of the orbits
    pa 15 deg caldwell
  20. what causes the dorsum sellae to be projected above the foramen magnum in an ap towne axial view (2 things)
    underangulation or insufficient flexion of the neck
  21. over angulation of the CR or excessive flexion causes what in an ap town axial view
    superimposes the posterior arch of C1 over the dorsum sellae w/in the foramen magnum which causes foreshortening of the dorsum sellae
  22. what is the anatomy demonstrated in a right lateral skull
    entire cranium with superimposed parietal bones entire view of sell turcica with anterior and posterior clinoids processes and dorsum sellae
  23. In the pa axial caldwell 25-30 deg angle where are the petrous pyramids
    Where is the cr
    • projected at or just below the IOM
    • centered to exit at the nasion
  24. what alternative position is used for patients who cannot flex the neck efficiently for an ap towne view
    pa axial (haas method)
  25. In the pa haas method is the patient face down or face up
    what line must be perp to IR
    What is the angle of the tube
    where is the CR and where does it exit
    • face down
    • OML
    • 25 deg cephalad
    • CR at level of EAM and exits 1.5 superior to nasion
  26. which projection of the skull produces an image of the frontal bone with little or no distoretion
    pa axial 0 deg cladwell
  27. what positioning error is present if the petrous ridges are projected higher in the orbits than expected for a 15 deg pa axial projection
    excessive flexion or insufficient CR angle
  28. which positioning error has been committed if the EAMs are superimposed with on of them more superior than the other on a lateral skull
    tilt of skull
  29. superimposition of the posterior arch of C1 over the dorsum sellae w/in the
    foramen magnum which causes foreshortening of the dorsum sellae is caused by what error in a townes view
    overangulation of CR or excessive flexion of neck
  30. No tilt is evident in an SMV projection of the skull by what
    by the equakl distance between mandibular ramus and lateral cranial cortex
  31. what anatomy is demonstrated in the pa axial haas method
    No rotation is evident by what structures
    • same as a townes
    • symmetrical bilateral petrous ridges