Paranasal Sinuses

Week 10

Fall 2009

DRAFT

Anterior Sinus Anatomy

•Purpose of sinuses

______

______

______

______

______

Lateral Sinus Anatomy

Aerated at birth

–______

Age 6-7

–______

–______

Puberty- approx 17-18 yrs

–______

Maxillary Sinuses

______sinuses

–3.5 cm high

–2.5 – 3 cm wide

Within maxilla

–Above upper teeth

Paired & symmetric

Communicates with ______

Frontal Sinuses

______largest sinuses

–2 – 2.5 cm

Normally:

–Between tables of vertical plate in frontal bone

–Can extend beyond frontal bone inot the orbital plates

Rarely ______

Number varies (occassionally absent)

Drain into ______

Sphenoid Sinuses

______sella turcica

–Extends between dorsum sellae and post clinoid processes

Can be single or paired

–Usually no more than ______

Drains into ______

Ethmoid Sinuses

Within ______masses of ethmoid bone

Three groups:

–Anterior, middle & posterior

______

–2-8 cells

–Drains into middle nasal meatus

______

–2-6 cells

–Drain into superior nasal meatus

Osteomeatal complex – coronal view

______

–Frontal, ethmoid and maxillary

______

–Infundibulum

–Middle nasal meatus

Osteomeatal Complex

Paranasal Sinuses Protocols

Lateral

PA (Caldwell)

Parietoacanthial (Waters)

Parietoacanthial (Open mouth Waters)

SMV

Technical Considerations

Radiographic density is critical

______diminishes or obliterates pathology

______can simulate pathology

______focal spot

Clean screens

Perfect film/screen contact

No ______contrast

Air Fluid Levels

Lateral Projection

Methods:

______

Lines and planes:

______

______

CR:

______

Lateral Sinuses

Lateral Radiograph

•All 4 sinuses

–Sphenoid of primary interest

•No rotation

•SI orbital roofs, mandibular rami

•Close beam restriction

•Clear air-fluid levels

Caldwell

Methods:

______

____grid 15 degrees:

 OML & MSP perp

Nose & forehead

______grid:

Tip of nose on grid and use sponge

OML 15 from CR

CR

horizontal to exit nasion

Caldwell Radiograph
Frontal & Anterior ethmoid

•No rotation

•Petrous ridges symmetric

•Petrous ridge in lower 1/3 of orbits

•Frontal sinus above frontonasal suture

•Anterior ethmoid cells above petrous ridges

•Frontal &ethmoid air cells

•Air fluid levels

•Close beam restriction

Waters for Maxillary sinuses

Methods:

______

Lines and planes:

______

______

CR:

______

Waters

Waters Radiograph

•Petrose just below maxillary sinuses

•No rotation

•Orbits & maxillary sinuses symmetric

•Close beam restriction

•Clear air-fluid levels

Open Mouth Waters for Maxillary / sphenoid sinuses

Methods:

______

Lines and Planes:

______

______

CR:

______

Open mouth Waters Radiograph

•Petrous ridges below maxillary sinuses

•No rotation

•Maxillary sinuses

•Close beam restriction

•Clear air-fluid levels

•Sphenoid sinuses through open mouth

SMV for ethmoidal and sphenoidal sinuses

Methods:

______

Lines and planes:

______

CR:

SMV Sinuses

SMV Radiograph

•No tilt or rotation

•Anterior frontal bone SI over mental protuberance

•Mandibular condyles anterior to petrous pyramids

•Clear air-fluid levels

Pathologic Indications

______

•Acute

•Chronic

Secondary ______

______

______

______

______

______

______

______

______

______

______

______

Mastoiditis

______