SINUSES VIEWS Flashcards
Functions of the Paranasal Sinuses
-Serve as resonating chamber for the voice
-Decrease the weight of the skull by containing air
-Help warm and moisten inhaled air
-Act as shock absorbers in trauma
-Possibly control the immune system
T or F: Maxillary sinuses are present at birth
True
T or F: Sinuses are not completely developed until 17-18 years of age
True
Maxillary sinuses are also known as
Antrum of Highmore
Labeling of the Paranasal Sinuses
The most superior sinus is the
Frontal
The most posterior sinus is the
Sphenoidal
The most inferior sinus is the
Maxillary
The largest sinus is the
Maxillary
How should sinuses images be taken and why?
Must be performed upright position with a horizontal CR because it’s the best demonstration of air fluid levels and differentiates fluid from other pathologic conditions
LATERAL Positioning
-MSP: II to IR
-IPL: ⟂ to IR
-IOML: II to long axis of IR (or ⟂ to front edge of IR)
-CR: 0.5-1” posterior to outer canthus
-SID: 40”
-Respiration: suspend
LATERAL Evaluation Criteria
-Proper Collimation
-All four sinus groups, best demonstration of sphenoid sinus
-No rotation or tilt
-SI orbital roofs
-SI mandibular rami
-Sella turcica in profile
-Brightness and contrast sufficient to visualize air fluid levels, if present
PA AXIAL CALDWELL Positioning
-Rest tip of nose on grid device and center the nasion to the IR so the OML forms a 15 degree angle OR tilt the grid down 15 degrees
-CR: perpendicular exiting the nasion
-SID: 40”
-Adjust the MSP perpendicular to the IR
-Respiration: suspend
PA AXIAL CALDWELL Evaluation Criteria
-Proper collimation
-Frontal sinuses lying above the frontonasal suture and anterior ethmoid cells lying above petrous ridges
-No rotation or tilt
-Equal distances from lateral borders of skull to lateral borders of orbits
-Symmetric petrous ridges
-MSP of cranium aligned with long axis of field
-Petrous pyramids in lower 1/3 of orbits
PARIETOACANTHIAL WATERS Positioning
-MSP is ⟂ to IR
-OML forms an angle of 37º from plane of IR
-MML is approximately ⟂ to IR
-CR: perpendicular exiting the acanthion
-Place patients chin on the grid adjusting the neck so that the MML is perpendicular to the IR
-Respiration: suspend