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
PARIETALCANTHIAL WATERS Evaluation Criteria
-Proper Collimation
-Maxillary sinuses
-OML in proper position as demonstrated by:
-Petrous pyramids lying immediately inferior to the floor of the maxillary sinuses
-No rotation or tilt demonstrated by:
-Equal distances between the lateral border of the skull and the lateral border of the orbit on both sides
-Orbits and maxillary sinuses symmetric on each side
-MSP of head aligned with the long axis of collimated field
-Air fluid levels if present
PARIETALCANTHIAL WATERS (OPEN MOUTH) 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, open mouth
-Respiration: suspend
PARIETALCANTHIAL WATERS (OPEN MOUTH) Evaluation Criteria
-Proper collimation
-Sphenoid sinuses projected through the open mouth
-Maxillary sinuses
-OML in proper position
-Petrous pyramids lying inferior to the floor to the maxillary sinuses
-No rotation or tilt
-Equal distances from lateral borders of skull to lateral borders of orbit on both sides
-Orbits and maxillary sinuses symmetric
-MSP of head aligned with long axis of field
MODIFIED WATERS Planes and lines
MSP is ⟂ to IR
OML forms an angle of 55º from plane of IR
LML is ⟂ to IR
MODIFIED WATERS
What view can show blowout fractures
Modified Waters
SUBMENTOVERTICAL (SMV) Positioning
-MSP is ⟂ to IR
-IOML is II to IR
-CR: Enters the MSP of the throat between the gonions
⟂ to IOML
⟂ to sella turcica
3/4” anterior to the EAM
-Respiration: Suspend
SUBMENTOVERTICAL (SMV) Evaluation Criteria
-Proper collimation
-Sphenoid and ethmoid sinuses
-No tilt
Equal distances from lateral borders of skull to mandibular condyles
-IOML is parallel to IR
-Mental protuberance SI over anterior frontal bone
-Insufficient neck extension will cause mandible to superimpose ethmoid sinuses
-Mandibular condyles anterior to petrosal
What projection shows the Paranasal sinuses?
Lateral
