Positioning for Paranasal sinuses Flashcards
Essential Projections for Sinuses
Lateral
Posteroanterior (PA) axial (Caldwell method)
Parietoacanthial (Waters method)
Parietoacanthial (Waters method) open-mouth modification
Submentovertical (SMV)
why is upright needed for sinuses
Need upright for fluid levels
how should the CR be ?
CR must be horizontal
What is the view that shows all four sets of sinuses ?
Lateral projection
- frontal
- maxillary
-ethmoid
sphenoid
what does the lateral projection of the sinuses demonstrate
All four sets of sinuses
Anteroposterior (AP) and superoinferior dimensions of paranasal sinuses
Thickness of frontal bone
Detail of side closer to image receptor (IR)
how is the IOML for the lateral projection of the sinuses
Infraorbitomeatal line (IOML) perpendicular to front edge of IR
how is the MSP for the lateral projection of the sinuses
Midsagittal plane (MSP) of head parallel with IR plane
CR for the lateral projection of the sinuses
Horizontal and perpendicular to IR
Enters ½ to 1 inch (1.3 to 2.5 cm) posterior to outer canthus
Center IR to CR
how is the IPL for the lateral projection of the sinuses
Interpupillary line (IPL) perpendicular to IR plane
what does the PA Axial Projection (Caldwell Method) demonstrates
Frontal sinuses above frontonasal suture
Anterior ethmoid air cells
Sphenoid sinuses seen through nasal fossa below or between ethmoids
Petrous pyramids in lower third of orbits
What sinuses is best demonstrated for PA axial Projection Caldwell
frontal sinuses and anterior ethmoid air cells
how are the petrous ridges in the PA Axial Projection (Caldwell Method)
Petrous pyramids in lower third of orbits
what is the sphenoid sinuses seen through in the PA Axial Projection (Caldwell Method)
Sphenoid sinuses seen through nasal fossa below or between ethmoids not well demonstrated
part position for the PA axial Caldwe
Tilt vertical Bucky down 15 degrees or rest on nose to put head at 15 degrees
Rest patient’s forehead and nose on device
what should be centered to IR in PA Axial (Caldwell Method)
Nasion
how is the msp and oml in the PA Axial (Caldwell Method)
MSP and orbitomeatal line (OML) perpendicular to IR plane