Positioning for Paranasal Sinuses

Question 1

Essential Projections for Sinuses

Answer 1

Lateral

Posteroanterior (PA) axial (Caldwell method)

Parietoacanthial (Waters method)

Parietoacanthial (Waters method) open-mouth modification

Submentovertical (SMV)

Question 2

why is upright needed for sinuses

Answer 2

Need upright for fluid levels

Question 3

how should the CR be ?

Answer 3

CR must be horizontal

Question 4

What is the view that shows all four sets of sinuses ?

Answer 4

Lateral projection

Question 5

what does the lateral projection of the sinuses demonstrate

Answer 5

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)

Question 6

how is the MSP for the lateral projection of the sinuses

Answer 6

Midsagittal plane (MSP) of head parallel with IR plane

Question 7

how is the IPL for the lateral projection of the sinuses

Answer 7

Interpupillary line (IPL) perpendicular to IR plane

Question 8

how is the IOML for the lateral projection of the sinuses

Answer 8

Infraorbitomeatal line (IOML) perpendicular to front edge of IR

Question 9

CR for the lateral projection of the sinuses

Answer 9

Horizontal and perpendicular to IR
Enters ½ to 1 inch (1.3 to 2.5 cm) posterior to outer canthus
Center IR to CR

Question 10

what does the PA Axial Projection (Caldwell Method) demonstrates

Answer 10

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

Question 11

how are the petrous ridges in the PA Axial Projection (Caldwell Method)

Answer 11

Petrous pyramids in lower third of orbits

Question 12

what is the sphenoid sinuses seen through in the PA Axial Projection (Caldwell Method)

Answer 12

Sphenoid sinuses seen through nasal fossa below or between ethmoids

Question 13

part position for the PA axial Caldwell

Answer 13

Tilt vertical Bucky down 15 degrees
Rest patient’s forehead and nose on device

Question 14

what should be centered to IR in PA Axial (Caldwell Method)

Answer 14

Nasion

Question 15

how is the msp and oml in the PA Axial (Caldwell Method)

Answer 15

MSP and orbitomeatal line (OML) perpendicular to IR plane

Question 16

how should the patients OML be positioned for PA Axial (Caldwell Method)

Answer 16

Position patient’s OML at 15-degree angle to horizontal CR

Question 17

CR for PA Axial (Caldwell Method)

Answer 17

Horizontal
Exits nasion
Center IR and CR

Question 18

how do you get the PA axial caldwell method

Answer 18

either angle bucky or angle the OML 15 degrees

Question 19

what is demonstrated in the Parietoacanthial Projection (Waters Method

Answer 19

Maxillary sinuses
Petrous pyramids lying inferior to maxillary floor
Frontal and ethmoid sinuses are distorted

Question 20

what are the four sinuses

Answer 20

frontal, ethmoid, maxillary, and sphenoid

Question 21

how is the MSP and MML in the
Parietoacanthial Projection (Waters Method)

Answer 21

MSP and mentomeatal line (MML) perpendicular to IR plane

Question 22

what degree is the OML in the
Parietoacanthial Projection (Waters Method)

Answer 22

37 degrees

Question 23

how should the head be positioned in the Parietoacanthial Projection (Waters Method)

Answer 23

Hyperextend neck to place OML at 37-degree angle from IR plane

Question 24

how is the CR in the Parietoacanthial Projection (Waters Method)

Answer 24

CR:
Horizontal
Exits acanthion

Question 25

how is the patient positioned for the Parietoacanthial Projection (Open-Mouth Waters Method)

Answer 25

Seated erect facing Bucky MSP centered to midline

Question 26

how is the head positioned in the Parietoacanthial Projection (Open-Mouth Waters Method)

Answer 26

Hyperextend neck to place OML at 37-degree angle from IR plane

Question 27

what is the degree of the OML in the Parietoacanthial Projection (Open-Mouth Waters Method)

Answer 27

37 degrees

Question 28

how is the head positioned in the Parietoacanthial Projection (Open-Mouth Waters Method)

Answer 28

Hyperextend neck to place OML at 37-degree angle from IR plane

Question 29

how is the MSP and MML in the Parietoacanthial Projection (Open-Mouth Waters Method)

Answer 29

MSP and MML perpendicular to IR plane

Question 30

what is the CR for Parietoacanthial Projection (Open-Mouth Waters Method)

Answer 30

Horizontal Exits acanthion

Question 31

what does the Parietoacanthial Projection (Open-Mouth Waters Method) demonstrate

Answer 31

Sphenoid sinuses through open mouth Maxillary sinuses Petrous pyramids lying inferior to maxillary floor

Question 32

how are the petrous ridges in the open mouth waters method

Answer 32

they lie inferior to maxillary floor

Question 33

how is the head positioned in the SMV

Answer 33

Hyperextend neck and rest vertex of head on vertical grid device

Question 34

how is the MSP in the SMV

Answer 34

MSP perpendicular to IR plane

Question 35

how is the IOML in the SMV projection

Answer 35

Neck extended to place IOML parallel to IR plane

Question 36

CR for the SMV projection

Answer 36

Horizontal and perpendicular to IOML Enters MSP ¾ inch (1.9 cm) anterior to level of external acoustic meatus (EAM)

Question 37

what does the SMV projection demonstrate

Answer 37

Sphenoid and ethmoid sinuses Mandible Bony nasal septum

Question 38

Which sinuses are best demonstrated on the parietoacanthial projection (Waters method)?

Answer 38

Maxillary

Question 39

Which sinuses are best demonstrated on the PA axial projection (Caldwell method)?

Answer 39

Frontal