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Skull Positioning
Sinuses
Question | Answer |
---|---|
What are the views for Sinuses? | Lateral, Caldwell, Waters, SMV |
In the views of sinuses, the patient is always _______ and the CR is __________. | upright, horizontal |
Describe the patients position in the Lateral Sinuses. | Patient is upright in an RAO or LAO with te head turned lateral |
What line(s) are parallel and which line(s) are perpendicular? | MSP and IOML are parallel, IPL is perpendicular |
What is the entrance point of the central ray for lateral sinuses? | perpendicular, entering 1/2 - 1" posterior to outer canthus |
What is demonstrated in Lateral Sinuses? | All four sinus groups, superimposed orbital roofs, mandibular rami, sinuses clearly visible, air/fluid levels, no rotation of sellla turcica |
Which group of sinuses are primarily seen? | sphenoid |
What SID is used for the lateral sinuses? When is the SID changed? | 40" SID except when for pre-op it should be done 72" SID |
If patient is unable to sit upright for lateral sinuses, what can be done to show air/fluid levels? | cross-table lateral |
What kVp do we use for skull work? | 65-75 kVp |
Describe the patients position for the Caldwell Sinuses? | Upright, OML perpendicular and then lift chin up so that the OML is 15 degrees from perpendicular |
The central ray exits the ______ in the Caldwell Sinuses. | nasion |
What is the angle of the CR in the Caldwell Sinuses? | There is no angle. The CR is perpendicular. |
What is demonstrated in the Caldwell Sinuses? | Frontal sinuses above the frontonasal suture, ethmoid sinuses above the petrous ridges, Petrous ridges in lower 1/3 of orbit, lateral borders of skull equal, close collimation |
What is another name for the Waters sinuses view? | parietoacanthial projection |
Describe the patients position in the Waters sinus view? | Patent is upright with chin extended. MML perpendicular. |
The OML forms a ________ to film in the Waters sinus view. | 37 degree angle |
The central ray exits at the ______. | acanthion |
Petrous pyramids inferior to floor of maxillary sinuses, maxillary sinuses ar demonstrated in what view of the sinuses? | Waters |
SMV stands for ________. | submentovertical |
Describe the patients position for the SMV sinuses. | Patient is upright with neck extended back to place the crown of head on IR. |
What line is parellel to the film? | IOML |
In the SMV sinuses, the CR enters _______ to the ______ throught the _______. | perpendicular, IOML, Sella turcica |
If an SMV sinuses is not able to be done, what other method can be done? | Open mouth Waters |
What is best demonstrated in the SMV sinuses? | sphenoidal and ethmoidal air cells |
What is demonstrated in the SMV sinuses? | sphenoidal and ethmoidal air cells, anterior frontal bone superimposed by mandibular symphysis, mandibular condyles anterior to petrous pyramids, no rotation |