31 terms

Head & neck imaging

STUDY
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frontal sinuses
visualized using the PA axial projection (Caldwell method)
ethmoidal sinuses
visualized using the PA axial projection (Caldwell method)
sphenoidal sinuses
well demonstrated in the SMV projection
maxillary sinuses
best demonstrated using the parietoacanthial projection (Waters' method)
The lateral projection demonstrates
the four pairs of paranasal sinuses superimposed on each other.
Blowout fractures of the orbit are best demonstrated using the
parietoacanthial projection (Waters' method)
Blowout fractures of the orbital floor are well demonstrated by using
Waters' method [parietoacanthial (PA) projection] and by using tomographic studies.
A PA with the OML perpendicular and the central ray angled 30° caudad will demonstrate
the orbital floor in profile
Sweet's localization method shows
exact placement of foreign bodies within the eye
The parietoacanthial projection (Waters' method) demonstrates
a distorted view of the frontal and ethmoidal sinuses. The maxillary sinuses are well demonstrated, projected free of the petrous pyramids. This is also the best single position for the demonstration of facial bones.
At what level do the carotid arteries bifurcate?
C4
The common carotid arteries function to
supply oxygenated blood to the head and neck
Major branches of the common carotid arteries (internal carotids) function to
supply the anterior brain, while the posterior brain is supplied by the vertebral arteries (branches of the subclavian)
The carotid arteries bifurcate into internal and external carotid arteries at the level of
C4
The true lateral position of the skull uses which of the following principles?
1. Interpupillary line perpendicular to the IR
2. Infraorbitomeatal line (IOML) parallel to the transverse axis of the IR
In a routine lateral projection of the skull, the central ray should enter approximately
2 inches superior to the EAM.
in a routine lateral projection of the skull the patient is placed in a
PA oblique position
Which of the following structures should be visualized through the foramen magnum in the AP axial projection (Grashey method) of the skull for occipital bone?
1. Posterior clinoid processes
2. Dorsum sella
The AP axial projection (Grashey method) of the skull requires that the central ray be
angled 30° caudad if the OML is perpendicular to the image receptor (37° caudad if the IOML is perpendicular to the image receptor)
The AP axial projection (Grashey method) of the skull
The frontal and facial bones are projected down and away from superimposition on the occipital bone. If positioning is accurate, the dorsum sella and posterior clinoid processes will be demonstrated within the foramen magnum.
in the AP axial projection (Grashey method) of the skull if the central ray is angled excessively,
the posterior aspect of the arch of C1 will appear in the foramen magnum.
Lateral deviation of the nasal septum may be best demonstrated in the
parietoacanthial (Waters' method) projection
the PA axial (Caldwell method) projection
superimposes the petrous structures over the nasal septum, while the lateral projection superimposes and obscures good visualization of the septum
The AP axial projection is used to demonstrate
the occipital bone
With the patient in the PA position, the rami can be better demonstrated with
20° to 25° cephalad angulation
In a lateral projection of the nasal bones, the central ray is directed
3/4 inch distal to the nasion
During studies of the soft tissue of the neck, the exposure can be made
1. during phonation before/after opacification.
2. during Valsalva maneuver.
3. at the height of swallowing motion with opacification.
Soft tissue neck studies can be performed for a number of reasons including
to determine presence of foreign body or to evaluate the swallowing mechanism following a stroke event.
Phonation of various vowel sounds, with or without contrast media opacification, can help demonstrate
the vocal cords
Performance of the Valsalva maneuver
fills the larynx and trachea with air, which is then well demonstrated on soft tissue study
Pharyngeal structures are demonstrated during
swallowing motion