The paranasal sinuses should always be examined in the

Chapter 11: Cranium Long: Merrill’s Atlas of Radiographic Positioning and Procedures, 14th Edition. Part 5 The paranasal sinuses should always be examined in the

upright position to:

• demonstrate the presence or absence of fluid.
• differentiate between fluid and other pathologic conditions.
• make it easier for the radiographer to position the patient.
• 1 and 2
• 1 and 3
• 2 and 3
• 1, 2, and 3 - Correct Answers ✅a. 1 and 2

For a lateral projection of the paranasal sinuses, the central

ray is directed:

• 1 inch posterior to the outer canthus.
• 2 inches posterior to the outer canthus.
• 1 inch anterior to the EAM.
• 2 inches anterior to the EAM - Correct Answers ✅a. 1

inch posterior to the outer canthus.All of the following should be clearly demonstrated on a lateral projection of the paranasal sinus, except: 1 / 3

Chapter 11: Cranium Long: Merrill’s Atlas of Radiographic Positioning and Procedures, 14th Edition. Part 5

• all four paranasal sinus groups.
• petrous ridge in lower third of orbits.
• sella turcica in profile.
• superimposed orbital roofs. - Correct Answers ✅b.

petrous ridge in lower third of orbits.Which projection will best demonstrate the frontal and anterior ethmoidal sinuses?

• PA
• Parietoacanthial (Waters)
• PA axial (Caldwell)
• SMV - Correct Answers ✅c. PA axial (Caldwell)

Which of the following must be projected below the maxillary sinuses for the parietoacanthial projection (Waters method) of the sinuses?

• Zygomatic bones
• Petrous pyramids
• Inferior orbital margin
• Sphenoidal sinuses - Correct Answers ✅b. Petrous

pyramids 2 / 3

Chapter 11: Cranium Long: Merrill’s Atlas of Radiographic Positioning and Procedures, 14th Edition. Part 5 When using the angled grid technique for the PA axial (Caldwell method) projection of the sinuses, the vertical grid device must be angled _____ degrees.

• 7
• 10
• 15
• 20 - Correct Answers ✅c. 15

The parietoacanthial projection (Waters method) of the sinuses requires the orbitomeatal line to be placed how many degrees from the plane of the image receptor?

• 20 degrees
• 27 degrees
• 30 degrees
• 37 degrees - Correct Answers ✅d. 37 degrees

Which sinus is projected through the mouth on the open- mouth modification of the Waters method?

• Frontal
• Ethmoidal
• Sphenoidal
• / 3