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Rad Pro Ch.11 Part 1
Paranasal Sinuses
Question | Answer |
---|---|
Paranasal Sinuses | Large air-filled cavities are sometimes called the accessory nasal sinuses because they are linked with mucous membrane. |
Maxillary Sinuses | Large; are paired structures, one of which is located within the body of each maxillary bone. |
Older term for maxillary sinus is? | Antrum. |
Nasal Cavity | Is divided into 2 equal chambers or fossae. |
The radiographic positioning of the paranasal sinuses should be accomplished with the patient in the _______ position to delineate any possible air-fluid levels. | Erect. |
Frontal Sinuses | Are located between the inner and outer tables of the skull, posterior to the glabella and they rarely become aerated before age 6. |
Ethmoid Sinuses | Are contained within the lateral masses or labyrinths of the ethmoid bone. |
Sphenoid Sinuses | Lie in the body of the sphenoid bone directly below the sella turcica. |
Sphenoid Effusion | The air-fluid level may provide evidence that the patient has a basal skull fracture and that either blood or cerebrospinal fluid is leaking through the fracture into the sphenoid sinuses. |
Osteomeatal Complex | Made up by the drainage pathways of the frontal, maxillary, and ethmoid sinuses. |
Sinusitis | Infection of the sinuses. |
Large Maxillary Sinus | Drains through the infundibulum passageway through the middle nasal meatus into the inferior nasal meatus. |
Ethmoid Bulla | Receies drainage from the frontal and ethmoid sinus cells which drains down through the middle nasal meatus into the inferior nasal meatus where it exits the body through the exterior nasal orifice. |
Uncinate Process | Of the ethmoid bone makes up the medial wall of the infundibulum passageway. |
Each orbit is a _____________, bony-walled structure. | Cone-shapped. |
Base | The rim of the orbit which corresponds to the outer circular portion of the cone; but is seldom a true circle. |
Apex | The posterior portion of the cone; corresponds to the optic nerve through which the optic nerve passes. |
Each orbit is composed of ____ bones? | 7. |
Forms the base of the orbit: | Frontal bone, Zygoma, and Maxilla. |
Lacrimal bone | A portion of the medial wall of the orbit. |
Sphenoid & Ethmoid Bones | Make up most of the posterior orbit. |
Palatine Bone | Contributes to the innermost posterior portion of the floor of each orbit. |
The 7 Bones that make up at orbit include ____ cranial bones and _____ facial bones. | 3- Frontal, Sphenoid, & Ethmoid. 4- Maxilla, Zygoma, Lacrimal, Palatine. |
Optic Foramen | Is a small hole in the sphenoid bone that is located posteriorly at the apex of the cone-shaped orbit that allows passage of the optic nerve which is a continuation of the retina. |
Superior Orbital Fissure | Is a cleft or opening between the greater & lesser wings of the sphenoid bone, located lateral to the optic foramen that allows transmission of 4 primary cranial nerves which control movement of the eye and eyelid. |
Inferior Orbital Fissure | Located between the maxilla, zygomatic bone, and grater wing of the sphenoid; it allows for transmission of the maxillary branch of CNV which permits entry of sensory innervation for the cheek, nose, upper lip & teeth. |
Sphenoid Strut | the small root of bone that separates the superior orbital fissure from the optic canal. |
TECHNICAL CONSIDERATIONS FOR SINUSES: | 1. Erect. 2. Horizontal beam. 3. AEC not recommended. |
Lateral Sinuses | CR midway between outer canthus and EAM. |
PA Sinuses: Caldwell | - OML perpendicular to IR, 15° tilt . - OML 15° from horizontal. - Horizontal CR; CR exits nasion. * Frontal and ethmoid sinuses demonstrated. * Petrous ridges in lower ⅓ of orbits. |
Parietoacanthial Sinuses: Waters Method | - MML perpendicular to IR forms a 37° angle with the plan of IR. - CR horizontal, to exit at acanthion. * Maxillary sinuses demonstrated. * Petrous ridges below maxillary sinuses. |
SMV Sinuses | - IOML parallel to IR. - Horizontal CR, between angles of mandible. * Mandibular condyles anterior to petrous ridges. |
PA Transoral Sinuses: Open-Mouth Waters Method | - MML perpendicular to IR. - Open mouth. - Horizontal CR, exit at acanthion. * Sphenoid sinus visualized. * Frontal and maxillary sinuses also included. * Petrous ridges below maxillary sinuses. |