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RADT 425
Ch 11 Cranium
Question | Answer |
---|---|
On a PA cranium/ mandible projection, the distances from the lateral margin of orbits to the lateral cranial ___ from the crista galli to the lateral cranial cortices and from the mandibular rami to the lateral cervical vertebrae on both sides are equal. | cortices |
On a PA cranium/mandible projection, the anterior clinoids and dorsum sellae are seen superior to the ___ ____. | ethmoid sinuses |
On a PA cranium/ mandible projection, the petrous ridges are superimposed over the ___ ___ and the internal acoustic meatus are visualized horizontally through the center of the orbits. | supraorbital margins |
On a PA cranium/mandible projection, the crista galli and ___ ___ are aligned with the long axis of the exposure field and the supraorbital margins and the TMJs are demonstrated on the same horizontal plane. | nasal septum |
The midsagittal plane is positioned ___-to the IR for a PA cranial projection to prevent rotation. | perpendicular |
PA and AP skull projections demonstrate different magnified anatomic structures. Which of these projections demonstrates the greater orbital magnification? | AP |
PA and AP skull projections demonstrate different magnified anatomic structures. Which of these projections demonstrates the greater parietal bone magnification? | PA |
What cranial positioning line is used to obtain an accurate PA projection? | OML |
How is the OML positioned with respect to the IR for a PA cranial projection? | perpendicular |
What 2 anatomic structures are aligned with the long axis on the projection if the patient's midsagittal plane is accurately aligned with the collimated field on a PA or AP cranial projection? | crista galli and nasal septum |
On a PA or AP cranial projection with accurate positioning, the ___ ___ is centered within the collimated field. This centering is obtained when the CR is centered to the ___. | dorsum sellae, glabella |
What anatomic structures are included on a PA or AP mandibular projection with accurate centering? | the entire mandible |
On a AP axial cranium, facial bones and sinuses projection, the distances from the lateral orbital margins to the ___ __ ___ on both sides and from the crista galli to the lateral cranial cortices on both sides are equal. | lateral cranial cortices |
On a PA axial cranium, the petrous ridges are demonstrated horizontally through the lower 3rd of the ___, the petrous ridges are superimposed over the ____ ___ and the superior orbital fissures are seen within the orbits. | orbits, infraorbital margins |
On a Pa cranium, facial bones or sinuses projection, the ___ ___ and nasal septum are aligned with the long axis of the exposure field and the supraorbital margins are demonstrated on the same horizontal plane. | crista galli |
What plane is positioned perpendicular to the IR for a PA axial projection? | midsagittal |
What is the CR angulation for a PA axial projection of the cranium for a patient who can tuck the chin only enough to place the OML at a 10-degree cephalad angle with the IR? | 5 degree caudal |
What is the CR angulation for an AP axial projection of the cranium for a patient who can tuck the chin only enough to place the OML at a 5-degree caudal angle with the IR? | 10-degrees cephalic |
On a PA and AP axial projection with accurate positioning, the ____ ___ are centered within the exposure filed. This is accomplished by centering the CR to the ____. | ethmoid sinuses, nasion |
On an AP axial cranium/ mandible projection, the distances from the posterior clinoid process to the lateral borders of the ___ ___ on both sides and the mandibular necks to the lateral cervical vertebrae on both sides are equal. | foramen magnum |
On an AP axial cranium/mandible projection, the petrous ridges are symmetrical and the dorsum sellae is centered within the ___ ___. | foramen magnum |
On an AP axial cranium projection, the dorsum sellae and ___ ___ are seen within the foramen magnum without foreshortening or superimposition of the atlas' posterior arch. | posterior clinoids |
On an AP axial mandible projection, the dorsum sellae and posterior clinoids are at the level of the ____foramen magnum and the mandibular condyles and fossae are clearly demonstrated with minimal mastoid superimposition. | superior |
On an AP axial cranium/mandible projection, the ___ ___ and nasal septum are aligned with the long axis of the exposure field. | sagittal suture |
The ____plane is positioned ___to the IR to prevent rotation on an AP axial projection. | midsagittal, perpendicular |
When rotation is present on an AP axial projection, the side demonstrating less distance between the posterior clinoid process and the lateral border of the foramen magnum is the side ____which the patient's face is rotated. | toward |
When the correct CR angulation and head position are used on an AP axial projection, the ___ ___ and posterior clinoids are demonstrated within the ___ ___> | dorsum sellae, foramen magnum |
What cranial positioning line is aligned perpendicular to the IR for an AP axial projection of the cranium? | OML |
On a lateral cranium, facial bones and sinuses projection, when visualized, the sella turcica is seen __ ___, orbital roofs, mandibular rami, greater wings of the sphenoid, external acoustic canals, zygomatic bones and cranial cortices are ____. | in profile, superimposed |
On a lateral cranium projection, the posteroinferior occipital bones and ___ ___ of the atlas are free of superimposition. | posterior arch |
What sinuses are demonstrated on a lateral projection of the sinuses? | sphenoid, ethmoid, frontal and maxillary |
What plane is used to position the patient to prevent rotation and tilting on a lateral cranial projection? | midsagittal |
How is the MSP aligned with the IR for a lateral cranial projection? | parallel |
How does proper MSP alignment align the interpupillary line with the IR? | perpendicular |
On a lateral cranial projection with accurate positioning, the Cr is centered 2 inches ____ to the ____. | superior, EAM |
On a SMV projection, the mandibular mentum and nasal fossae are demonstrated just anterior to the ___ ___. | ethmoid sinuses |
On a SMV projection, the distances from the mandibular ramus and body to the ___ ___ ___ on both sides are equal. | lateral cranial cortex |
On a SMV projection, the vomer, bony nasal septum and ___are aligned with the long axis of the exposure field. | dens |
Accurate mandibular mentum and nasal fossae positioning on a SMV cranial projection is obtained when the ____ cranial positioning line is aligned ___ with the IR. | IOML, parallel |
What structures are obscured on a SMV cranial projection if the patient's neck is not adequately extended? | nasal fossae, ethmoid sinuses, foramen ovale, foramen spinosum |
On a SMV cranial projection with accurate positioning, the ___ is centered within the exposure field. | dens |
On a SMV sinus and mandible image with accurate positioning, the ___ ___ are centered within the exposure field. | sphenoid sinuses |
On a parietoacanthial/acanthioparietal facial bones & sinuses projection, the distances from the ___ ___ ___ to the lateral cranial cortices and the distance from the bony nasal septum to the lateral cranial cortex on both sides are equal. | lateral orbital margins |
On a parietoacanthial/acanthioparietal facial bones & sinuses projection, the petrous ridges are demonstrated ____ to the maxillary sinuses and extend ___from the posterior maxillary process. | inferior, laterally |
On a parietoacanthial/acanthioparietal facial bones & sinuses projection, the bony nasal septum is aligned with the long axis of the exposure field and the ___ ___ are demonstrated on the same horizontal plane. | infraorbital margins |
What sinuses are demonstrated on an open-mouth parietoacanthial projection that are not demonstrated on a closed-mouth parietoacanthial projection? | sphenoid sinuses |
When rotation is present on a parietoacanthial projection, the patient's face is rotated ___ the side of the cranium that demonstrates the greatest distance. | away from |
On a parietoacanthial projection with accurate positioning, the ___ ___ ___ is centered within the exposure field. This is accomplished by centering the CR to the ____. | anterior nasal spine, acanthion |