This document provides an overview of paranasal sinus anatomy and radiographic procedures. It describes the locations and functions of the maxillary, frontal, ethmoid, and sphenoid sinuses. Key radiographic projections discussed include lateral, PA axial, parietoacanthial, and submentovertical views. Proper patient positioning and technical factors are outlined to demonstrate the sinuses and ensure diagnostic image quality.

1. Chapter 22 Paranasal Sinuses Lesson 1 Anatomy and Procedures of the Paranasal Sinuses Prof. Z. Vinokur

2. Paranasal Sinuses Defined as the air-filled cavities located in the frontal, ethmoid, and sphenoid bones of the cranium, as well as the maxillae of the face So named because of their formation from the nasal mucosa and their continued communication with the nasal fossas Prof. Z. Vinokur

3. Functions Serve as resonating chamber for the voice Decrease weight of skull Aid in warming and moisturizing inhaled air Act as shock absorbers in trauma Possibly control the immune system Prof. Z. Vinokur

4. Development Begins in fetal life Maxillary sinuses are usually the only ones developed enough to be demonstrated radiographically at birth By 6 to 7 years of age, frontal and sphenoid are distinguishable from ethmoids Ethmoids do not fully develop until 17 to 18 years of age Prof. Z. Vinokur

5. Maxillary Sinuses Largest and most symmetric Paired (one in each facial bone) Vary in size and shape but are roughly pyramidal in shape Prof. Z. Vinokur

6. Frontal Sinuses Second largest Paired Located between vertical plates of frontal bone Vary greatly in size and shape Occasionally absent Rarely symmetric Prof. Z. Vinokur

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8. Ethmoid Sinuses Located within lateral masses of labyrinths Comprised of varying number of air cells, which are divided into three main groups Anterior (2 to 8) Middle (2 to 8) Posterior (2 to 6) Prof. Z. Vinokur

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10. Sphenoid Sinuses Normally paired Occupy body of sphenoid bone Often only one sinus develops, but never more than two Vary in size and shape Usually asymmetric Located below sella and extend between dorsum and posterior ethmoids Prof. Z. Vinokur

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13. Essential Projections Lateral PA axial (Caldwell method) Parietoacanthial (Waters method) Parietoacanthial (Waters) open-mouth modification Submentovertical Prof. Z. Vinokur

14. Technical Considerations Density most critical to demonstrate pathology Upright position necessary to demonstrate fluid levels CR should remain horizontal Shielding must be used on pregnant patients and pediatric patients Proper collimation critical in reducing scatter radiation and patient dose Prof. Z. Vinokur

15. Lateral Projection Prof. Z. Vinokur Demonstrates All four sets of sinuses AP and superoinferior dimensions of paranasal sinuses Thickness of frontal bone Detail of side closer to IR

16. Lateral Projection Patient position Seated erect in anterior oblique position Part position MSP of head parallel with IR plane IPL perpendicular to IR plane IOML parallel to transverse axis of cassette Prof. Z. Vinokur

17. Lateral Projection CR Horizontal and perpendicular to IR Enters ½  to 1  (1.3 to 2.5 cm) posterior to outer canthus Center IR to CR Prof. Z. Vinokur

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20. PA Axial Projection (Caldwell Method) Prof. Z. Vinokur 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

21. PA Axial (Caldwell Method) Angled Grid Technique Patient position Seated upright facing Bucky MSP centered to midline Prof. Z. Vinokur

22. PA Axial (Caldwell Method) Patient position Tilt vertical Bucky down 15 degrees Rest patient’s forehead and nose on device Center nasion to IR MSP and OML perpendicular to IR plane Prof. Z. Vinokur

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24. PA Axial (Caldwell Method) Vertical Grid Technique Position patient’s OML at 15-degree angle to horizontal CR Center nasion to IR MSP perpendicular Radiolucent support may be needed at forehead This method is not preferred due to increased OID, which results in decreased resolution Prof. Z. Vinokur

25. PA Axial (Caldwell Method) CR Horizontal Exits nasion Center IR and CR Prof. Z. Vinokur

26. Parietoacanthial Projection (Waters Method) Prof. Z. Vinokur Demonstrates Maxillary sinuses Petrous pyramids lying inferior to maxillary floor Frontal and ethmoid sinuses are distorted

27. Patient position Seated erect facing Bucky MSP centered to midline Part position Hyperextend neck to place OML at 37-degree angle from IR plane MSP and MML perpendicular to IR plane Parietoacanthial Projection (Waters Method) Prof. Z. Vinokur

28. CR Horizontal Exits acanthion Parietoacanthial Projection (Waters Method) Prof. Z. Vinokur

29. Parietoacanthial Projection (Open-Mouth Waters Method) Prof. Z. Vinokur Demonstrates Sphenoid sinuses through open mouth Maxillary sinuses Petrous pyramids lying inferior to maxillary floor

30. Patient position Seated erect facing Bucky MSP centered to midline Part position Hyperextend neck to place OML at 37-degree angle from IR plane MSP and MML perpendicular to IR plane Open mouth wide while holding position Parietoacanthial Projection (Open-Mouth Waters Method) Prof. Z. Vinokur

31. CR Horizontal Exits acanthion Parietoacanthial Projection (Open-Mouth Waters Method) Prof. Z. Vinokur

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35. SMV Projection Prof. Z. Vinokur Demonstrates Sphenoid and ethmoid sinuses Mandible Bony nasal septum

36. SMV Projection Patient position Upright Part position Hyperextend neck and rest vertex of head on vertical grid device MSP perpendicular to IR plane Neck extended to place IOML parallel to IR plane Prof. Z. Vinokur

37. SMV Projection CR Horizontal and perpendicular to IOML Enters MSP ¾  (1.9 cm) anterior to level of EAM Prof. Z. Vinokur

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40. Image Critique Criteria for Essential Projection Slide

41. Lateral Projection All four sinus groups Sphenoid of primary importance No rotation of sella turcica Superimposed orbital roofs Superimposed mandibular rami Clearly visible sinuses Close beam restriction Clearly visible air-fluid levels, if present Prof. Z. Vinokur

42. Lateral Projection Prof. Z. Vinokur

43. Prof. Z. Vinokur L LATERAL SKULL CORONAL SUTURE LAMBOID SUTURE INT. & EXT. OCCIPITAL PERTUBERANCE MASTOID AIR CELLS HARD PALATE NASOPHARYNX ANTERIOR CLINOID POSTERIOR CLINOID MANDIBULAR CONDYLE FLOOR OF THE CRANIAL FOSSA SELLA TURCICA FRONTAL SINUS MAXILLARY SINUS SPHENOID SINUS ETHMOID SINUS

44. PA Axial (Caldwell Method) No rotation Equal distance between lateral border of skull and lateral border of orbits Petrous ridges symmetric Petrous ridge lying in lower third of orbit Frontal sinuses above frontonasal suture and anterior ethmoidal air cells above petrous ridges Prof. Z. Vinokur

45. PA Axial (Caldwell Method) Frontal and anterior ethmoidal air cells Clearly visible air-fluid levels, if present Close beam restriction Prof. Z. Vinokur

46. Prof. Z. Vinokur SINUS CALDWELL VIEW FRONTAL SINUS SPHENOID BONE MAXILLARY SINUS INFERIOR TURBINATE MANDIBLE HARD PALATE MASTOID AIR CELLS ORBIT ETHMOID

47. Prof. Z. Vinokur ETHMOID SINUS NASAL SEPTUM MASTOID AIR CELLS MAXILLARY SINUS MAXILLA GREATER WING OF SPHENOID AP SKULL

48. PA Axial (Caldwell Method) Prof. Z. Vinokur

49. Petrous pyramids immediately inferior to floor of maxillary sinuses No rotation Equal distance between lateral border of skull and lateral border of orbit Orbits and maxillary sinuses symmetric Maxillary sinuses Close beam restriction Clearly visible air-fluid levels, if present Parietoacanthial Projection (Waters Method) Prof. Z. Vinokur

50. Prof. Z. Vinokur Sinus WATERS VIEW MANDIBLE FRONTAL SINUS ETHMOID SINUS MAXILLARY SINUS ZYGOMA ZYGOMATIC ARCH INFERIOR ORBITAL MARGIN ORBIT NASAL SEPTUM ZYGOMATICAL –FRONTAL SUTURE ODONTOID

51. Prof. Z. Vinokur Sinus AP FRONTAL SINUS ETHIMOID SINUS ORBIT NASAL SEPTUM GREATER WING OF SPHENOID MAXILLARY SINUS

52. Parietoacanthial (Waters) Prof. Z. Vinokur

53. Petrous pyramids immediately inferior to floor of maxillary sinuses No rotation Equal distance between lateral border of skull and lateral border of orbit Orbits and maxillary sinuses symmetric Maxillary sinuses Parietoacanthial Projection (Open-Mouth Waters Method) Prof. Z. Vinokur

54. Close beam restriction Clearly visible air-fluid levels, if present Sphenoid sinuses projected through open mouth Parietoacanthial Projection (Open-Mouth Waters Method) Prof. Z. Vinokur

55. Parietoacanthial (Waters) Prof. Z. Vinokur

56. SMV Projection No tilt Equal distance from lateral border of skull to mandibular condyles on both sides Anterior frontal bone superimposed by mental protuberance Indicates IOML is parallel (full extension) Mandibular condyles anterior to petrous pyramids Clearly visible air-fluid levels, if present Prof. Z. Vinokur

57. SMV Projection Prof. Z. Vinokur

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59. Prof. Z. Vinokur SKULL TOWNE VIEW MANDIBLE MASTOID AIR CELLS PETROUS TEMPORAL BONE FORAMEN MAGNUM PARIETAL BONES LAMBDOID SUTURE LAMBDOID SUTURE

60. Prof. Z. Vinokur SKULL TOWNE VIEW MANDIBLE MASTOID AIR CELLS PETROUS TEMPORAL BONE FORAMEN MAGNUM PARIETAL BONES LAMBDOID SUTURE LAMBDOID SUTURE

61. Prof. Z. Vinokur ODONTOID PROCESS (DENS) ETHMOID SINUS SPHENOID SINUS MAXILLARY SINUS LAT. PTYERGOID PLATE FORAMEN OVALE ARCH OF C-1 EXT. AUDITORY CANAL MASTOID AIR CELLS BASE OF THE SKULL

62. Prof. Z. Vinokur FRONTAL SINUS LATERAL NASAL BONE NASAL BONES

63. Prof. Z. Vinokur FRONTAL SINUS MAXILLARY SINUS MANDIBLE MAXILLA ETHMOID SINUS SELLA TURCICA SPHENOID SINUS LATERAL FACIAL STRUCTURES

64. Prof. Z. Vinokur AIRWAY EPIGLOTTIS HYOID BONE CALCIFIED TRACHEAL CARTILAGE RINGS THYROID CARTILAGE CRICOID CARTILAGE

65. Prof. Z. Vinokur ARTERIOGRAM CAROTID SYPHON OCCIPITAL ARTERY INTERNAL CAROTID ARTERY EXTERNAL CAROTID ARTERY COMMON CAROTID ARTERY MAXILLARY ARTERY MIDDLE CEREBRAL ARTERY ANTERIOR CEREBRAL ARTERY FACIAL ARTERY

66. What is it supposed to look like Prof. Z. Vinokur http://www.jeffersonhospital.org/webcast/sinus/index.html

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68. links Prof. Z. Vinokur http://classes.kumc.edu/som/radanatomy/results2.asp?RegionID=1&PathologyID=2