Paranasal Sinuses Flashcards
2 sinuses present at birth:
Maxillary and ethmoid
4 groups of paranasal sinuses:
Frontal, maxillary, ethmoid, sphenoid
Passageways and connections of all the sinuses
Osteomeatal complex
CR centering for lateral sinuses
midway between outer canthus and EAM
____ perpendicular to IR for lateral sinuses
IPL
___ perpendicular to front edge of IR for lateral sinuses
IOML
OML aligned ___ degrees from horizontal for PA (Caldwell) sinuses
15
CR exits at ____ for PA (Caldwell) sinuses
nasion
_____ perpendicular to IR for parietoacanthial (waters) sinuses
MML
CR exists at ____ for parietoacanthial (waters) sinuses
acanthion
Alternative for SMV to visualize sphenoid sinuses
Open mouth Waters
____ parallel to IR for SMV sinuses
IOML
CR centering for SMV sinuses
2 inches inferior to mandibular symphysis
Chin elevation moves the maxillary sinuses _____ to the petrous ridges.
superior
A patient comes to radiology for a sinus series on a cart (gurney). She is unable to stand or sit erect for any of the projections. Which of the following projections will best detect any air/fluid levels present in the maxillary sinuses?
Horizontal beam lateral
A patient comes to radiology for a sinus series. She cannot fully extend her head and neck for the submentovertical projection. What else can the technologist do to produce a diagnostic submentovertical projection?
Angle the CR to place it perpendicular to IOML.
A radiograph of a PA projection of the sinuses reveals that the petrous ridges are projected over the ethmoid sinuses. Which of the following modifications will eliminate this superimposition while not compromising diagnostic quality of the study?
Increase extension of the head and neck slightly.
A radiograph of a parietoacanthial (Waters method) projection reveals that the petrous ridges are superimposed over the lower 30% of the maxillary sinuses. What specific positioning error (if any) led to this radiographic finding?
Insufficient extension of skull and neck
T/F: All of the sinuses intercommunicate with each other and with the nasal cavity.
True
Along with the use of erect positions, what other technical factor is important to demonstrate air/fluid levels in paranasal sinuses?
Horizontal CR
T/F: Both CT (computed tomography) and MRI (magnetic resonance imaging) can provide reconstructed images in three planes: axial, sagittal, and coronal.
True
T/F: Infections involving the upper teeth may involve the frontal sinuses.
False
The ____ sinuses develop last and are not fully developed until the teenage years.
Ethmoid
